Vena cava filters were introduced in the 1960s as a mechanical means to prevent pulmonary embolism (PE).1 Since that time, the number of filters placed has grown steadily, to over 49,000 annually in the United States alone.2 However, patients with vena cava filters can develop complications from the filter itself, which can lead to significant morbidity and, rarely, mortality. In particular, the interruption of venous flow caused by the filter can precipitate lower extremity deep vein thrombosis (DVT),3 as well as vena caval thrombosis involving the filter itself. This has led some experts to recommend indefinite anticoagulation in patients with vena caval filters,4, 5 potentially exposing many patients to the risks of anticoagulation. Given these long‐term safety concerns, there has been recent enthusiasm for the development of optional filters. Optional vena cava filters can be classified into 2 types: temporary and retrievable. Temporary filters, which are not currently available in the United States, are held in place by a tether or catheter5 and cannot be used as permanent devices. Retrievable filters, on the other hand, maintain their position by hooks, radial pressure, or barbs and can either be removed within a prescribed time period after placement or remain in place permanently. In this way, optional filters offer the possibility of avoiding long‐term filter complications in patients with temporary contraindications to anticoagulation. Not surprisingly, the use of retrievable filters has increased dramatically, with many filters being placed for prophylactic indications in patients without known venous thromboembolism (VTE).6 In this work we review the different types of retrievable vena cava filters, current indications for placement, complications, and areas for future research.

Filter Design and Efficacy

Currently, there are 5 U.S. Food and Drug Administration (FDA)‐approved filters in the United States that can be used as retrievable filters: ALN (ALN Implants Chirurgicaux, Ghisonaccia, France); Celect (Cook Medical Incorporated, Bloomington, IN); Gunther‐Tulip (Cook Medical Incorporated, Bloomington, IN); G2 (Bard Peripheral Vascular, Tempe, AZ); and OptEase (Cordis Corporation, Miami Lakes, FL) (Table 1). Three more devices are in U.S. clinical trials: SafeFlo (Rafael Medical Technologies, Hasselt, Belgium); Crux (Crux Biomedical, Portola Valley, CA); and Option (Rex Medical, Conshohocken, PA). Filters are constructed from magnetic resonance imaging (MRI)‐compatible, nonferromagnetic alloys and are produced in either a hexagonal or conical shape. There are potential advantages and disadvantages to both designs. A hexagonal design is thought to be better for trapping small thrombi, but conical filters may have a decreased propensity toward thrombosis.7 When a hexagonal filter becomes partially occluded in vitro, flow disturbances can lead to turbulence, stasis, and progressive clot formation.7 Some clinical studies have demonstrated an increased incidence of thrombosis with hexagonal filters,8 but further investigation is needed to determine if a true correlation exists. Comparisons of the 2 types of filter design are limited but have shown no difference in their efficacy in the prevention of PE.9 Therefore, filter choice is usually dependent upon the physician performing the procedure, although other factors, such as caval size, clot extent, available venous access, and route of retrieval also may affect this decision. Furthermore, retrospective reviews have shown no difference in efficacy between retrievable and permanent filters.10

Insertion of filters is typically performed under fluoroscopy in the operating room or interventional radiology suite. Placement can also occur at the bedside using intravascular ultrasound. This option is particularly useful for critically ill patients who are not stable enough to leave the intensive care unit (ICU) for insertion. The safety of this approach has been documented for both retrievable and permanent filters.11, 12 Duplex ultrasonography has been used to allow bedside placement of permanent filters, but published experience with this modality in placement of retrievable filters is lacking.13, 14

There are no set time limits for retrieving filters, although the retrieval success rate decreases as the time postplacement increases. Rather, the decision to remove them is based on the clinical situation. Table 1 shows data on some of the longest documented successful dwell times for the various retrievable filters. Prior to filter retrieval, a venogram is performed to ensure that there is no clot in the inferior vena cava (IVC) or common iliac veins (Figure 1). Removal of a retrievable filter involves snaring one end of the filter with a hook and then slipping a sheath over the filter, which retracts the filter from the vessel wall as it is being pulled into the sheath (Figure 2). Retrieval rates from various studies are listed in Table 2. Common reasons for nonretrieval include loss to follow up,15 ongoing contraindications to anticoagulation,11, 1618 presence of large thrombi in the filter,16, 1820 poor patient prognosis,16, 18 unrelated death,1618 and filter tilting or embedment.19, 21

Figure 1

Figure 2

Indications for Filter Placement

Filter Complications

During Filter Retrieval

Filter tilting and clot trapping under the filter that occurs during the filter removal process are infrequent causes of non‐retrieval. Tilting of the filter sometimes can pose problems, but if this occurs, the filter can be repositioned so that the degree of tilt no longer precludes removal. Severe cases of tilting that lead to nonretrieval are very rare. When thrombus is trapped in the filter (Figure 3), retrieval often depends on the amount of thrombus. A visual scale to assist in judgment of thrombus volume has been developed to assist in retrieval decision‐making.33 In some cases, catheter‐directed thrombolysis has been used to facilitate thrombus dissolution.34

Figure 3

Conclusions

There is growing concern over the increased use of vena caval filters for the prevention of PE.41 Retrievable filters offer the possibility of protection without the risk of long‐term complications attributable to permanent filters. The advent of these devices has lead to an increase in overall filter use but also could result in filter placement without adequate consideration of the potential complications or consequences of nonretrieval. More evidence is needed in order to establish best practice guidelines for retrievable filter use. Until these data are available, these devices should be used only in patients with acute VTE who are at risk for recurrent thromboembolism and have a transient risk for bleeding.

Vena cava filters were introduced in the 1960s as a mechanical means to prevent pulmonary embolism (PE).1 Since that time, the number of filters placed has grown steadily, to over 49,000 annually in the United States alone.2 However, patients with vena cava filters can develop complications from the filter itself, which can lead to significant morbidity and, rarely, mortality. In particular, the interruption of venous flow caused by the filter can precipitate lower extremity deep vein thrombosis (DVT),3 as well as vena caval thrombosis involving the filter itself. This has led some experts to recommend indefinite anticoagulation in patients with vena caval filters,4, 5 potentially exposing many patients to the risks of anticoagulation. Given these long‐term safety concerns, there has been recent enthusiasm for the development of optional filters. Optional vena cava filters can be classified into 2 types: temporary and retrievable. Temporary filters, which are not currently available in the United States, are held in place by a tether or catheter5 and cannot be used as permanent devices. Retrievable filters, on the other hand, maintain their position by hooks, radial pressure, or barbs and can either be removed within a prescribed time period after placement or remain in place permanently. In this way, optional filters offer the possibility of avoiding long‐term filter complications in patients with temporary contraindications to anticoagulation. Not surprisingly, the use of retrievable filters has increased dramatically, with many filters being placed for prophylactic indications in patients without known venous thromboembolism (VTE).6 In this work we review the different types of retrievable vena cava filters, current indications for placement, complications, and areas for future research.

Filter Design and Efficacy

Currently, there are 5 U.S. Food and Drug Administration (FDA)‐approved filters in the United States that can be used as retrievable filters: ALN (ALN Implants Chirurgicaux, Ghisonaccia, France); Celect (Cook Medical Incorporated, Bloomington, IN); Gunther‐Tulip (Cook Medical Incorporated, Bloomington, IN); G2 (Bard Peripheral Vascular, Tempe, AZ); and OptEase (Cordis Corporation, Miami Lakes, FL) (Table 1). Three more devices are in U.S. clinical trials: SafeFlo (Rafael Medical Technologies, Hasselt, Belgium); Crux (Crux Biomedical, Portola Valley, CA); and Option (Rex Medical, Conshohocken, PA). Filters are constructed from magnetic resonance imaging (MRI)‐compatible, nonferromagnetic alloys and are produced in either a hexagonal or conical shape. There are potential advantages and disadvantages to both designs. A hexagonal design is thought to be better for trapping small thrombi, but conical filters may have a decreased propensity toward thrombosis.7 When a hexagonal filter becomes partially occluded in vitro, flow disturbances can lead to turbulence, stasis, and progressive clot formation.7 Some clinical studies have demonstrated an increased incidence of thrombosis with hexagonal filters,8 but further investigation is needed to determine if a true correlation exists. Comparisons of the 2 types of filter design are limited but have shown no difference in their efficacy in the prevention of PE.9 Therefore, filter choice is usually dependent upon the physician performing the procedure, although other factors, such as caval size, clot extent, available venous access, and route of retrieval also may affect this decision. Furthermore, retrospective reviews have shown no difference in efficacy between retrievable and permanent filters.10

Insertion of filters is typically performed under fluoroscopy in the operating room or interventional radiology suite. Placement can also occur at the bedside using intravascular ultrasound. This option is particularly useful for critically ill patients who are not stable enough to leave the intensive care unit (ICU) for insertion. The safety of this approach has been documented for both retrievable and permanent filters.11, 12 Duplex ultrasonography has been used to allow bedside placement of permanent filters, but published experience with this modality in placement of retrievable filters is lacking.13, 14

There are no set time limits for retrieving filters, although the retrieval success rate decreases as the time postplacement increases. Rather, the decision to remove them is based on the clinical situation. Table 1 shows data on some of the longest documented successful dwell times for the various retrievable filters. Prior to filter retrieval, a venogram is performed to ensure that there is no clot in the inferior vena cava (IVC) or common iliac veins (Figure 1). Removal of a retrievable filter involves snaring one end of the filter with a hook and then slipping a sheath over the filter, which retracts the filter from the vessel wall as it is being pulled into the sheath (Figure 2). Retrieval rates from various studies are listed in Table 2. Common reasons for nonretrieval include loss to follow up,15 ongoing contraindications to anticoagulation,11, 1618 presence of large thrombi in the filter,16, 1820 poor patient prognosis,16, 18 unrelated death,1618 and filter tilting or embedment.19, 21

Figure 1

Figure 2

Indications for Filter Placement

Filter Complications

During Filter Retrieval

Filter tilting and clot trapping under the filter that occurs during the filter removal process are infrequent causes of non‐retrieval. Tilting of the filter sometimes can pose problems, but if this occurs, the filter can be repositioned so that the degree of tilt no longer precludes removal. Severe cases of tilting that lead to nonretrieval are very rare. When thrombus is trapped in the filter (Figure 3), retrieval often depends on the amount of thrombus. A visual scale to assist in judgment of thrombus volume has been developed to assist in retrieval decision‐making.33 In some cases, catheter‐directed thrombolysis has been used to facilitate thrombus dissolution.34

Figure 3

Conclusions

There is growing concern over the increased use of vena caval filters for the prevention of PE.41 Retrievable filters offer the possibility of protection without the risk of long‐term complications attributable to permanent filters. The advent of these devices has lead to an increase in overall filter use but also could result in filter placement without adequate consideration of the potential complications or consequences of nonretrieval. More evidence is needed in order to establish best practice guidelines for retrievable filter use. Until these data are available, these devices should be used only in patients with acute VTE who are at risk for recurrent thromboembolism and have a transient risk for bleeding.

Vena cava filters were introduced in the 1960s as a mechanical means to prevent pulmonary embolism (PE).1 Since that time, the number of filters placed has grown steadily, to over 49,000 annually in the United States alone.2 However, patients with vena cava filters can develop complications from the filter itself, which can lead to significant morbidity and, rarely, mortality. In particular, the interruption of venous flow caused by the filter can precipitate lower extremity deep vein thrombosis (DVT),3 as well as vena caval thrombosis involving the filter itself. This has led some experts to recommend indefinite anticoagulation in patients with vena caval filters,4, 5 potentially exposing many patients to the risks of anticoagulation. Given these long‐term safety concerns, there has been recent enthusiasm for the development of optional filters. Optional vena cava filters can be classified into 2 types: temporary and retrievable. Temporary filters, which are not currently available in the United States, are held in place by a tether or catheter5 and cannot be used as permanent devices. Retrievable filters, on the other hand, maintain their position by hooks, radial pressure, or barbs and can either be removed within a prescribed time period after placement or remain in place permanently. In this way, optional filters offer the possibility of avoiding long‐term filter complications in patients with temporary contraindications to anticoagulation. Not surprisingly, the use of retrievable filters has increased dramatically, with many filters being placed for prophylactic indications in patients without known venous thromboembolism (VTE).6 In this work we review the different types of retrievable vena cava filters, current indications for placement, complications, and areas for future research.

Filter Design and Efficacy

Currently, there are 5 U.S. Food and Drug Administration (FDA)‐approved filters in the United States that can be used as retrievable filters: ALN (ALN Implants Chirurgicaux, Ghisonaccia, France); Celect (Cook Medical Incorporated, Bloomington, IN); Gunther‐Tulip (Cook Medical Incorporated, Bloomington, IN); G2 (Bard Peripheral Vascular, Tempe, AZ); and OptEase (Cordis Corporation, Miami Lakes, FL) (Table 1). Three more devices are in U.S. clinical trials: SafeFlo (Rafael Medical Technologies, Hasselt, Belgium); Crux (Crux Biomedical, Portola Valley, CA); and Option (Rex Medical, Conshohocken, PA). Filters are constructed from magnetic resonance imaging (MRI)‐compatible, nonferromagnetic alloys and are produced in either a hexagonal or conical shape. There are potential advantages and disadvantages to both designs. A hexagonal design is thought to be better for trapping small thrombi, but conical filters may have a decreased propensity toward thrombosis.7 When a hexagonal filter becomes partially occluded in vitro, flow disturbances can lead to turbulence, stasis, and progressive clot formation.7 Some clinical studies have demonstrated an increased incidence of thrombosis with hexagonal filters,8 but further investigation is needed to determine if a true correlation exists. Comparisons of the 2 types of filter design are limited but have shown no difference in their efficacy in the prevention of PE.9 Therefore, filter choice is usually dependent upon the physician performing the procedure, although other factors, such as caval size, clot extent, available venous access, and route of retrieval also may affect this decision. Furthermore, retrospective reviews have shown no difference in efficacy between retrievable and permanent filters.10

Insertion of filters is typically performed under fluoroscopy in the operating room or interventional radiology suite. Placement can also occur at the bedside using intravascular ultrasound. This option is particularly useful for critically ill patients who are not stable enough to leave the intensive care unit (ICU) for insertion. The safety of this approach has been documented for both retrievable and permanent filters.11, 12 Duplex ultrasonography has been used to allow bedside placement of permanent filters, but published experience with this modality in placement of retrievable filters is lacking.13, 14

There are no set time limits for retrieving filters, although the retrieval success rate decreases as the time postplacement increases. Rather, the decision to remove them is based on the clinical situation. Table 1 shows data on some of the longest documented successful dwell times for the various retrievable filters. Prior to filter retrieval, a venogram is performed to ensure that there is no clot in the inferior vena cava (IVC) or common iliac veins (Figure 1). Removal of a retrievable filter involves snaring one end of the filter with a hook and then slipping a sheath over the filter, which retracts the filter from the vessel wall as it is being pulled into the sheath (Figure 2). Retrieval rates from various studies are listed in Table 2. Common reasons for nonretrieval include loss to follow up,15 ongoing contraindications to anticoagulation,11, 1618 presence of large thrombi in the filter,16, 1820 poor patient prognosis,16, 18 unrelated death,1618 and filter tilting or embedment.19, 21

Figure 1

Figure 2

Indications for Filter Placement

Filter Complications

During Filter Retrieval

Filter tilting and clot trapping under the filter that occurs during the filter removal process are infrequent causes of non‐retrieval. Tilting of the filter sometimes can pose problems, but if this occurs, the filter can be repositioned so that the degree of tilt no longer precludes removal. Severe cases of tilting that lead to nonretrieval are very rare. When thrombus is trapped in the filter (Figure 3), retrieval often depends on the amount of thrombus. A visual scale to assist in judgment of thrombus volume has been developed to assist in retrieval decision‐making.33 In some cases, catheter‐directed thrombolysis has been used to facilitate thrombus dissolution.34

Figure 3

Conclusions

There is growing concern over the increased use of vena caval filters for the prevention of PE.41 Retrievable filters offer the possibility of protection without the risk of long‐term complications attributable to permanent filters. The advent of these devices has lead to an increase in overall filter use but also could result in filter placement without adequate consideration of the potential complications or consequences of nonretrieval. More evidence is needed in order to establish best practice guidelines for retrievable filter use. Until these data are available, these devices should be used only in patients with acute VTE who are at risk for recurrent thromboembolism and have a transient risk for bleeding.

There is little scientific evidence about professional help‐seeking behavior among resident physicians. Although junior physicians have many sources of information available to them in the course of clinical practiceprint materials, internet resources, curbside consultations, and advice from senior residents and facultywe have little empirical knowledge about when, why, and how physician trainees ask for help.

To study this phenomenon, we examined the use of a medical procedure service (MPS) by resident physicians. The MPS is an inpatient service at a Boston teaching hospital that provides education, supervision, and evaluation of internal medicine residents who perform common bedside procedures; it has been described previously.1 Residents who call the MPS review an online curriculum with self‐assessment quizzes, perform procedures with faculty supervision and feedback, and assess their own performance using online checklists. This program has been available to internal medicine residents since 2002. In a previous study, we found that residents reported greater comfort performing bedside procedures when they used the procedure service, when the operator was a postgraduate year (PGY)2 or PGY3 resident (compared to PGY1 residents), and while placing central venous catheters (CVCs) (compared to thoracenteses).2

The goal of the current study was to examine help‐seeking behavior among resident physicians as they placed CVCs and performed thoracenteses. We interpreted the decision to use the MPS to indicate that the resident successfully sought and received assistance from pulmonary attending physicians or interventional pulmonary fellows. We hypothesized that: (1) residents earlier in their training would choose to use the procedure service due to their relative lack of experience; (2) they would seek consultation when the procedure was performed in high‐risk patients, as indicated by the number of comorbidities, presence of medications that increase the risk of bleeding, and treatment in an intensive care unit; and (3) residents would be less likely to call the MPS for urgent or emergent situations, when timely assistance may be difficult to obtain. To examine the potentially confounding influence of procedures supervised by non‐MPS physicians, we also investigated differences between informally supervised procedures (i.e. by a non‐MPS attending or fellow) and unsupervised procedures (i.e. no attending or fellow supervision) to determine whether any significant differences in their characteristics existed.

Methods

Results

Discussion

To understand professional help‐seeking behavior by internal medicine resident physicians, we studied factors associated with the use of a MPS for performing 2 common bedside procedures. We found that residents used the MPS more often when they performed procedures on patients with more comorbidities and less often during urgent or emergent procedures.

These results are consistent with our hypothesis that residents use formal supervision when caring for high‐risk patients. We had also hypothesized that they would seek the MPS for patients on medications that increase the risk of bleeding, but this was not borne out. One possible explanation is that invasive procedures on anticoagulated patients may be deferred or avoided. Additionally, we did not collect prothrombin times nor platelet count, which may represent better proxies for coagulopathy. Our hypothesis that residents would not seek the MPS for urgent and emergent procedures was confirmed; the time delay between contacting the faculty member and performing the procedure may have inhibited or obviated consultation of the MPS. We hypothesized that interns would use the MPS preferentially; we found instead that level of training did not influence use of the MPS. A resident early in training may struggle with the balance between autonomy and supervision, wanting instead to establish himself as able to solve clinical problems independently and by seeking consultation only as a last resort. Alternatively, interns may be primarily supervised by their residents and may seek expert assistance only for particularly challenging or high‐risk cases. Additionally, as newcomers to the training program, they may not be well acquainted with the role and availability of the service (although periodic announcements were made throughout the year). Our examination of procedures not supervised by the MPS showed that informally supervised and unsupervised procedures are quite similar to each other; the inverse relationship between informal supervision and patient gender is difficult to explain and may be spurious.

To our knowledge, only 1 author has postulated a theoretical foundation for help‐seeking in trainees, depicted in the context of the patient‐resident‐attending triadic relationship.4 The mature help‐seeker, whether patient, resident, or attending, is willing to confront problems, receptive to new information, able to acknowledge dependence on expertise, and able to apply new input with self‐reliance. However, little is known about how this model manifests itself empirically in professional help‐seeking or what the optimal conditions of faculty supervision are. One observational study suggested that faculty who spent more time on hospital floors created environments with higher resident satisfaction scores, higher perceived quality of patient care, and, paradoxically, increased perceptions of autonomy.5 These results are consistent with our previous work showing that residents' comfort with bedside procedures increased with use of the MPS.2 In the related field of consultation medicine, 2 studies6, 7 showed that family practitioners prefer to consult internal medicine subspecialists over general internists. One of these studies7 demonstrated that the primary need was for a consultant with technical (ie, procedural) skills. Our use of MPS faculty who are specifically skilled in performing medical procedures appears to be consistent with this observation that specific technical expertise is valued over general supervision or guidance.

How can we best design formal procedural supervision programs that allow residents to obtain help when they need it? In addition to fostering mature help‐seeking behavior, help‐giving requires: (1) an environment that encourages help‐seeking; (2) a mechanism to provide assistance when and where it is needed; (3) supervisors with technical expertise; and (4) supervision that supports learning, skill acquisition, and graduated autonomy. It is difficult to devise mechanisms that include all of these elements. For instance, 24‐hour per day faculty coverage may be logistically challenging and expensive. Physicians with technical expertise may not be good teachers despite faculty development on procedural teaching. Obstacles to successful help‐seeking may include differences in residents' and supervisors' perceptions about the need for supervision. For example, a supervisor may be available and willing to assist, but the resident may feel capable of performing independently. When assistance is provided, residents and supervisors may differ in their perceptions of the quality of supervision.8 Ultimately, any educational intervention to increase supervision must confront a cultural norm of self‐sufficiency among many residency programs, in which managing a situation without assistance is equated with competence. To address this issue, our hospital has mandated the use of the MPS for all bedside procedures since 2005 and staffed the program 24 hours a day, in recognition of the potential risk of procedural complications9, 10 among inexperienced trainees.

This study has several limitations. We had a small number of thoracenteses. The study was not designed or powered to examine differences in complication rates among MPS and non‐MPS procedures. Because we represent a single institution, our findings may not be generalizable to other teaching hospitals or nonteaching settings. Our data on procedure characteristics were ascertained through resident self‐reports and, though typically submitted in a timely way, are subject to recall bias. In particular, discrepancies in the reported level of urgency may have affected our results about the time‐dependent nature of help‐seeking. Additionally, our findings about the types of patients about which residents seek consultation are somewhat at odds; use of the modified Deyo criteria to adjust for clinical severity weighs chronic conditions heavily and may translate into complication risk, but the level of urgency may better reflect the acuity of the clinical presentation. We could not distinguish between resident‐supervised procedures and those performed without supervision because of limited data. We also acknowledge the possibility that some non‐MPS faculty (classified for the study as informal supervisors) may serendipitously provide an equal quality of supervision that our MPS faculty did, by being present throughout the procedure and giving structured and valuable feedback.

Nevertheless, our results suggest that many residents do seek formal help appropriately when they perform procedures on the sickest patients, recognizing the risk and technical difficulty associated with bedside procedures in these patients. Our results also point to a greater area of inquiry: how do we optimally address the help‐seeking needs among trainee physicians? How do we create an environment in which help‐seeking is encouraged? How do we overcome the logistical barriers of providing timely assistance to residents, particularly at times of greatest need (urgent or emergent procedures)? How do we confront a longstanding culture in which independence is equated with competence, especially as it relates to procedural skills? A better understanding of how the widespread availability of programs like our MPS would affect the residents' use of supervision in general may guide the design of resident curricula and the development of mechanisms to ensure safe and effective clinical care.

There is little scientific evidence about professional help‐seeking behavior among resident physicians. Although junior physicians have many sources of information available to them in the course of clinical practiceprint materials, internet resources, curbside consultations, and advice from senior residents and facultywe have little empirical knowledge about when, why, and how physician trainees ask for help.

To study this phenomenon, we examined the use of a medical procedure service (MPS) by resident physicians. The MPS is an inpatient service at a Boston teaching hospital that provides education, supervision, and evaluation of internal medicine residents who perform common bedside procedures; it has been described previously.1 Residents who call the MPS review an online curriculum with self‐assessment quizzes, perform procedures with faculty supervision and feedback, and assess their own performance using online checklists. This program has been available to internal medicine residents since 2002. In a previous study, we found that residents reported greater comfort performing bedside procedures when they used the procedure service, when the operator was a postgraduate year (PGY)2 or PGY3 resident (compared to PGY1 residents), and while placing central venous catheters (CVCs) (compared to thoracenteses).2

The goal of the current study was to examine help‐seeking behavior among resident physicians as they placed CVCs and performed thoracenteses. We interpreted the decision to use the MPS to indicate that the resident successfully sought and received assistance from pulmonary attending physicians or interventional pulmonary fellows. We hypothesized that: (1) residents earlier in their training would choose to use the procedure service due to their relative lack of experience; (2) they would seek consultation when the procedure was performed in high‐risk patients, as indicated by the number of comorbidities, presence of medications that increase the risk of bleeding, and treatment in an intensive care unit; and (3) residents would be less likely to call the MPS for urgent or emergent situations, when timely assistance may be difficult to obtain. To examine the potentially confounding influence of procedures supervised by non‐MPS physicians, we also investigated differences between informally supervised procedures (i.e. by a non‐MPS attending or fellow) and unsupervised procedures (i.e. no attending or fellow supervision) to determine whether any significant differences in their characteristics existed.

Methods

Results

Discussion

To understand professional help‐seeking behavior by internal medicine resident physicians, we studied factors associated with the use of a MPS for performing 2 common bedside procedures. We found that residents used the MPS more often when they performed procedures on patients with more comorbidities and less often during urgent or emergent procedures.

These results are consistent with our hypothesis that residents use formal supervision when caring for high‐risk patients. We had also hypothesized that they would seek the MPS for patients on medications that increase the risk of bleeding, but this was not borne out. One possible explanation is that invasive procedures on anticoagulated patients may be deferred or avoided. Additionally, we did not collect prothrombin times nor platelet count, which may represent better proxies for coagulopathy. Our hypothesis that residents would not seek the MPS for urgent and emergent procedures was confirmed; the time delay between contacting the faculty member and performing the procedure may have inhibited or obviated consultation of the MPS. We hypothesized that interns would use the MPS preferentially; we found instead that level of training did not influence use of the MPS. A resident early in training may struggle with the balance between autonomy and supervision, wanting instead to establish himself as able to solve clinical problems independently and by seeking consultation only as a last resort. Alternatively, interns may be primarily supervised by their residents and may seek expert assistance only for particularly challenging or high‐risk cases. Additionally, as newcomers to the training program, they may not be well acquainted with the role and availability of the service (although periodic announcements were made throughout the year). Our examination of procedures not supervised by the MPS showed that informally supervised and unsupervised procedures are quite similar to each other; the inverse relationship between informal supervision and patient gender is difficult to explain and may be spurious.

To our knowledge, only 1 author has postulated a theoretical foundation for help‐seeking in trainees, depicted in the context of the patient‐resident‐attending triadic relationship.4 The mature help‐seeker, whether patient, resident, or attending, is willing to confront problems, receptive to new information, able to acknowledge dependence on expertise, and able to apply new input with self‐reliance. However, little is known about how this model manifests itself empirically in professional help‐seeking or what the optimal conditions of faculty supervision are. One observational study suggested that faculty who spent more time on hospital floors created environments with higher resident satisfaction scores, higher perceived quality of patient care, and, paradoxically, increased perceptions of autonomy.5 These results are consistent with our previous work showing that residents' comfort with bedside procedures increased with use of the MPS.2 In the related field of consultation medicine, 2 studies6, 7 showed that family practitioners prefer to consult internal medicine subspecialists over general internists. One of these studies7 demonstrated that the primary need was for a consultant with technical (ie, procedural) skills. Our use of MPS faculty who are specifically skilled in performing medical procedures appears to be consistent with this observation that specific technical expertise is valued over general supervision or guidance.

How can we best design formal procedural supervision programs that allow residents to obtain help when they need it? In addition to fostering mature help‐seeking behavior, help‐giving requires: (1) an environment that encourages help‐seeking; (2) a mechanism to provide assistance when and where it is needed; (3) supervisors with technical expertise; and (4) supervision that supports learning, skill acquisition, and graduated autonomy. It is difficult to devise mechanisms that include all of these elements. For instance, 24‐hour per day faculty coverage may be logistically challenging and expensive. Physicians with technical expertise may not be good teachers despite faculty development on procedural teaching. Obstacles to successful help‐seeking may include differences in residents' and supervisors' perceptions about the need for supervision. For example, a supervisor may be available and willing to assist, but the resident may feel capable of performing independently. When assistance is provided, residents and supervisors may differ in their perceptions of the quality of supervision.8 Ultimately, any educational intervention to increase supervision must confront a cultural norm of self‐sufficiency among many residency programs, in which managing a situation without assistance is equated with competence. To address this issue, our hospital has mandated the use of the MPS for all bedside procedures since 2005 and staffed the program 24 hours a day, in recognition of the potential risk of procedural complications9, 10 among inexperienced trainees.

This study has several limitations. We had a small number of thoracenteses. The study was not designed or powered to examine differences in complication rates among MPS and non‐MPS procedures. Because we represent a single institution, our findings may not be generalizable to other teaching hospitals or nonteaching settings. Our data on procedure characteristics were ascertained through resident self‐reports and, though typically submitted in a timely way, are subject to recall bias. In particular, discrepancies in the reported level of urgency may have affected our results about the time‐dependent nature of help‐seeking. Additionally, our findings about the types of patients about which residents seek consultation are somewhat at odds; use of the modified Deyo criteria to adjust for clinical severity weighs chronic conditions heavily and may translate into complication risk, but the level of urgency may better reflect the acuity of the clinical presentation. We could not distinguish between resident‐supervised procedures and those performed without supervision because of limited data. We also acknowledge the possibility that some non‐MPS faculty (classified for the study as informal supervisors) may serendipitously provide an equal quality of supervision that our MPS faculty did, by being present throughout the procedure and giving structured and valuable feedback.

Nevertheless, our results suggest that many residents do seek formal help appropriately when they perform procedures on the sickest patients, recognizing the risk and technical difficulty associated with bedside procedures in these patients. Our results also point to a greater area of inquiry: how do we optimally address the help‐seeking needs among trainee physicians? How do we create an environment in which help‐seeking is encouraged? How do we overcome the logistical barriers of providing timely assistance to residents, particularly at times of greatest need (urgent or emergent procedures)? How do we confront a longstanding culture in which independence is equated with competence, especially as it relates to procedural skills? A better understanding of how the widespread availability of programs like our MPS would affect the residents' use of supervision in general may guide the design of resident curricula and the development of mechanisms to ensure safe and effective clinical care.

There is little scientific evidence about professional help‐seeking behavior among resident physicians. Although junior physicians have many sources of information available to them in the course of clinical practiceprint materials, internet resources, curbside consultations, and advice from senior residents and facultywe have little empirical knowledge about when, why, and how physician trainees ask for help.

To study this phenomenon, we examined the use of a medical procedure service (MPS) by resident physicians. The MPS is an inpatient service at a Boston teaching hospital that provides education, supervision, and evaluation of internal medicine residents who perform common bedside procedures; it has been described previously.1 Residents who call the MPS review an online curriculum with self‐assessment quizzes, perform procedures with faculty supervision and feedback, and assess their own performance using online checklists. This program has been available to internal medicine residents since 2002. In a previous study, we found that residents reported greater comfort performing bedside procedures when they used the procedure service, when the operator was a postgraduate year (PGY)2 or PGY3 resident (compared to PGY1 residents), and while placing central venous catheters (CVCs) (compared to thoracenteses).2

The goal of the current study was to examine help‐seeking behavior among resident physicians as they placed CVCs and performed thoracenteses. We interpreted the decision to use the MPS to indicate that the resident successfully sought and received assistance from pulmonary attending physicians or interventional pulmonary fellows. We hypothesized that: (1) residents earlier in their training would choose to use the procedure service due to their relative lack of experience; (2) they would seek consultation when the procedure was performed in high‐risk patients, as indicated by the number of comorbidities, presence of medications that increase the risk of bleeding, and treatment in an intensive care unit; and (3) residents would be less likely to call the MPS for urgent or emergent situations, when timely assistance may be difficult to obtain. To examine the potentially confounding influence of procedures supervised by non‐MPS physicians, we also investigated differences between informally supervised procedures (i.e. by a non‐MPS attending or fellow) and unsupervised procedures (i.e. no attending or fellow supervision) to determine whether any significant differences in their characteristics existed.

Methods

Results

Discussion

To understand professional help‐seeking behavior by internal medicine resident physicians, we studied factors associated with the use of a MPS for performing 2 common bedside procedures. We found that residents used the MPS more often when they performed procedures on patients with more comorbidities and less often during urgent or emergent procedures.

These results are consistent with our hypothesis that residents use formal supervision when caring for high‐risk patients. We had also hypothesized that they would seek the MPS for patients on medications that increase the risk of bleeding, but this was not borne out. One possible explanation is that invasive procedures on anticoagulated patients may be deferred or avoided. Additionally, we did not collect prothrombin times nor platelet count, which may represent better proxies for coagulopathy. Our hypothesis that residents would not seek the MPS for urgent and emergent procedures was confirmed; the time delay between contacting the faculty member and performing the procedure may have inhibited or obviated consultation of the MPS. We hypothesized that interns would use the MPS preferentially; we found instead that level of training did not influence use of the MPS. A resident early in training may struggle with the balance between autonomy and supervision, wanting instead to establish himself as able to solve clinical problems independently and by seeking consultation only as a last resort. Alternatively, interns may be primarily supervised by their residents and may seek expert assistance only for particularly challenging or high‐risk cases. Additionally, as newcomers to the training program, they may not be well acquainted with the role and availability of the service (although periodic announcements were made throughout the year). Our examination of procedures not supervised by the MPS showed that informally supervised and unsupervised procedures are quite similar to each other; the inverse relationship between informal supervision and patient gender is difficult to explain and may be spurious.

To our knowledge, only 1 author has postulated a theoretical foundation for help‐seeking in trainees, depicted in the context of the patient‐resident‐attending triadic relationship.4 The mature help‐seeker, whether patient, resident, or attending, is willing to confront problems, receptive to new information, able to acknowledge dependence on expertise, and able to apply new input with self‐reliance. However, little is known about how this model manifests itself empirically in professional help‐seeking or what the optimal conditions of faculty supervision are. One observational study suggested that faculty who spent more time on hospital floors created environments with higher resident satisfaction scores, higher perceived quality of patient care, and, paradoxically, increased perceptions of autonomy.5 These results are consistent with our previous work showing that residents' comfort with bedside procedures increased with use of the MPS.2 In the related field of consultation medicine, 2 studies6, 7 showed that family practitioners prefer to consult internal medicine subspecialists over general internists. One of these studies7 demonstrated that the primary need was for a consultant with technical (ie, procedural) skills. Our use of MPS faculty who are specifically skilled in performing medical procedures appears to be consistent with this observation that specific technical expertise is valued over general supervision or guidance.

How can we best design formal procedural supervision programs that allow residents to obtain help when they need it? In addition to fostering mature help‐seeking behavior, help‐giving requires: (1) an environment that encourages help‐seeking; (2) a mechanism to provide assistance when and where it is needed; (3) supervisors with technical expertise; and (4) supervision that supports learning, skill acquisition, and graduated autonomy. It is difficult to devise mechanisms that include all of these elements. For instance, 24‐hour per day faculty coverage may be logistically challenging and expensive. Physicians with technical expertise may not be good teachers despite faculty development on procedural teaching. Obstacles to successful help‐seeking may include differences in residents' and supervisors' perceptions about the need for supervision. For example, a supervisor may be available and willing to assist, but the resident may feel capable of performing independently. When assistance is provided, residents and supervisors may differ in their perceptions of the quality of supervision.8 Ultimately, any educational intervention to increase supervision must confront a cultural norm of self‐sufficiency among many residency programs, in which managing a situation without assistance is equated with competence. To address this issue, our hospital has mandated the use of the MPS for all bedside procedures since 2005 and staffed the program 24 hours a day, in recognition of the potential risk of procedural complications9, 10 among inexperienced trainees.

This study has several limitations. We had a small number of thoracenteses. The study was not designed or powered to examine differences in complication rates among MPS and non‐MPS procedures. Because we represent a single institution, our findings may not be generalizable to other teaching hospitals or nonteaching settings. Our data on procedure characteristics were ascertained through resident self‐reports and, though typically submitted in a timely way, are subject to recall bias. In particular, discrepancies in the reported level of urgency may have affected our results about the time‐dependent nature of help‐seeking. Additionally, our findings about the types of patients about which residents seek consultation are somewhat at odds; use of the modified Deyo criteria to adjust for clinical severity weighs chronic conditions heavily and may translate into complication risk, but the level of urgency may better reflect the acuity of the clinical presentation. We could not distinguish between resident‐supervised procedures and those performed without supervision because of limited data. We also acknowledge the possibility that some non‐MPS faculty (classified for the study as informal supervisors) may serendipitously provide an equal quality of supervision that our MPS faculty did, by being present throughout the procedure and giving structured and valuable feedback.

Nevertheless, our results suggest that many residents do seek formal help appropriately when they perform procedures on the sickest patients, recognizing the risk and technical difficulty associated with bedside procedures in these patients. Our results also point to a greater area of inquiry: how do we optimally address the help‐seeking needs among trainee physicians? How do we create an environment in which help‐seeking is encouraged? How do we overcome the logistical barriers of providing timely assistance to residents, particularly at times of greatest need (urgent or emergent procedures)? How do we confront a longstanding culture in which independence is equated with competence, especially as it relates to procedural skills? A better understanding of how the widespread availability of programs like our MPS would affect the residents' use of supervision in general may guide the design of resident curricula and the development of mechanisms to ensure safe and effective clinical care.

The Accreditation Council for Graduate Medical Education mandates that internal medicine residents develop technical proficiency in performing central venous catheterization (CVC).1 Likewise in Canada, technical expertise in performing CVC is a specific competency requirement in the training objectives in internal medicine by the Royal College of Physicians and Surgeons of Canada.2 For certification in Internal Medicine, the American Board of Internal Medicine expects its candidates to be competent with respect to knowledge and understanding of the indications, contraindications, recognition, and management of complications of CVC.3 Despite the importance of procedural teaching in medical education, most internal medicine residency programs do not have formal procedural teaching.4 A number of potential barriers to teaching CVC exist. A recent study by the American College of Physicians found that fewer general internists perform procedures, compared with internists in the 1980s.5 With fewer internists performing procedures, there may be fewer educators with adequate confidence in teaching these procedures.6 Second, with increasing recognition of patient safety, there is a growing reluctance of patients to be used as teaching subjects for those who are learning CVC.7 Not surprisingly, residents report low comfort in performing CVC.8

Teaching procedures on simulators offers the benefits of allowing both teaching and evaluation of procedures without jeopardizing patient safety9 and is a welcomed variation from the traditional see 1, do 1, teach 1 approach.10 Despite the theoretical benefits of the use of simulators in medical education, the efficacy of their use in teaching internal medicine residents remains understudied.

The purpose of our study was to evaluate the benefits of using simulator models in teaching CVC to internal medicine residents. We hypothesized that participation in a simulator‐based teaching session on CVC would result in improved knowledge and performance of the procedure and confidence.

Methods

Results

Of the 33 residents in the first‐year internal medicine program, all consented to participate. Thirty participants (91%) completed the study protocol between January and June 2007. The remaining three residents completed the presession assessments and the simulation session, but did not complete the postsession assessments. These were excluded from our analysis. At baseline, 20 participants had rotated through a previous 1‐month intensive care unit (ICU) block, 8 residents had no prior ICU training, and 2 residents had 2 months of ICU training. Table 1 summarizes the residents' baseline CVC experience prior to the simulation training. In general, participants had limited experience with CVC at baseline, having placed very few internal jugular CVCs (median = 4).

Simulation training was associated with an increase in knowledge. Mean scores on multiple‐choice tests increased from 65.7 11.9% to 81.2 10.7 (P < 0.001). Furthermore, simulation training was associated with improvement in CVC performance. Median global average rating score increased from 3.5 (IQR = 34) to 4.5 (IQR = 44.5) (P < 0.001).

The procedural checklist median score increased from 9 (IQR = 69.5) to 9.5 (IQR = 99.5) (P <.001), median time required for completion of CVC decreased from 8 minutes 22 seconds (IQR = 7 minutes 37 seconds to 12 minutes 1 second) to 6 minutes 43 seconds (IQR = 6 minutes to 7 minutes 25 seconds) (P = 0.002). Other performance measures are summarized in Table 2. Last, simulation training was associated with an increase in self‐rated confidence. The median confidence rating (0 lowest, 5 highest) increased from 3 (moderate, IQR = 23) to 4 (good, IQR = 34) (P < 0.001). The overall satisfaction with the CVC simulation course was good (Table 3) and all 30 participants felt this course should continue to be offered.

Discussion

CVC is an important procedural competency for internists to master. Indications for CVC range from measuring of central venous pressure to administration of specific medications or solutions such as inotropic agents and total parental nutrition. Its use is important in the care of those who are acutely or critically ill and those who are chronically ill. CVC is associated with a number of potentially serious mechanical complications, including arterial puncture, pneumothorax, and death.11, 17 Proficiency in CVC insertion is found to be closely related to operator experience: catheter insertion by physicians who have performed 50 or more CVC are one‐half as likely to sustain complications as catheter insertion by less experienced physicians.18 Furthermore, training has been found to be associated with a decrease in risk for catheter associated infection19 and pneumothorax.20 Therefore, cumulative experience from repeated clinical encounters and education on CVC play an important role in optimizing patient safety and reducing potential errors associated with CVC. It is well‐documented that patients are generally reluctant to allow medical trainees to learn or practice procedures on them,7 especially in the early phases of training. Indeed, close to 50% of internal medicine residents in 1 study reported poor comfort in performing CVCs.8

Deficiencies in procedural teaching in internal medicine residency curriculum have long been recognized.4 Over the past 20 years, there has been a decrease in the percentage of internists who place central lines in practice.5 In the United States, more than 5 million central venous catheters are inserted every year.21 Presumably, concurrent with this trend is an increasing reliance on other specialists such as radiologists or surgical colleagues in the placement of CVCs. Without a concerted effort for medical educators in improving the quality of procedural teaching, this alarming trend is unlikely to be halted.

With the advance of modern technology and medical education, patient simulation offers a new platform for procedural teaching to take place: a way for trainees to practice without jeopardizing patient safety, as well as an opportunity for formal teaching and supervision to occur,9, 22 serving as a welcomed departure from the traditional see 1, do 1, teach 1 model to procedural teaching. While there is data to support the role of simulation teaching in the surgical training programs,16, 23 less objective evidence exists to support its use in internal medicine residency training programs.

Our study supports the use of simulation in training first‐year internal medicine residents in CVC. Our formal curriculum on CVC involving simulation was associated with an increase in knowledge of the procedure, observed procedural performance, and subjective confidence. Furthermore, this improvement in knowledge and confidence was maintained at 18 months. Our study has several limitations, such as those inherent to all studies using the prestudy and poststudy design. Improvement in performance under study may be a result of the Hawthorne effect. We are not able to isolate the effect of self‐directed learning from the benefits from training using simulators. Furthermore, improvement in knowledge and confidence may be a function of time rather than training. However, by not comparing our results to that from a historical cohort, we hope to minimize confounders by having participants serve as their own control. Results from our study would be strengthened by the introduction of a control group and a randomized design. Future study should include a randomized, controlled crossover educational trial. The second limitation of our study is the low interobserver agreement between video raters, indicating only fair to moderate agreement. Although our video raters were trained senior medical residents and faculty members who frequently supervise and evaluate procedures, we did not specifically train them for the purposes of scoring videotaped performances. Further faculty development is needed. Overall, the magnitudes of the interobserver differences were small (mean global rating scale between raters differed by 1 0.9), and may not translate into clinically important differences. Third, competence on performing CVC on simulators has not been directly correlated with clinical competence on real‐life patients, although a previous study on surgical interns suggested that simulator training was associated with clinical competence on real patients.16 Future studies are warranted to investigate the association between educational benefits from simulation and actual error reductions from CVC during patient encounters. Fourth, our study did not examine residents in the use of ultrasound during simulator training. Use of ultrasound devices has been shown to decrease complication rates of CVC insertion24 and increase rates of success,25 and is recommended as the preferred method for insertion of elective internal jugular CVCs.26 However, because our course was introduced during first‐year residency, when majority of the residents have performed fewer than 5 internal jugular CVCs prior to their simulation training session, the objective of our introductory course was to first ensure technical competency by landmark techniques. Once learners have mastered the technical aspect of line insertion, ultrasound‐guided techniques were introduced later in the residency training curriculum. Fifth, only 48% of participants completed the knowledge assessment at 18 months. Selection bias may be present in our long‐term data. However, baseline comparisons between those who completed the 18 month assessment vs. those who did not demonstrated no obvious differences between the 2 groups. Performance was not examined in our long‐term data. Demonstration of retention of psychomotor skills would be reassuring. However, by 18 months, many of our learners had completed a number of procedurally‐intensive rotations. Therefore, because retention of skills could not be reliably attributed to our initial training in the simulator laboratory, the participants were not retested in their performance of the CVC. Future study should include a control group that undergoes delayed training at 18 months to best assess the effect of simulation training on performance. Sixth, only overall confidence in performing CVC was captured. Confidence in each venous access site pretraining and posttraining was not assessed and warrants further study. Last, our study did not document overall costs of delivering the program, including cost of the simulator, facility, supplies, and stipends for teaching faculty. One full‐time equivalent (FTE) staff has previously been estimated to be a requirement for the success of the program.9 Our program required 3 medical educators, all of whom are clinical faculty members, as well as the help of 4 chief medical residents.

Despite our study's limitations, our study has a number of strengths. To our knowledge, our study is the first of its kind examining the use of simulators on CVC procedural performance, with the use of video‐recording, in an independent and blinded manner. Blinding should minimize bias associated with assessments of resident competency by evaluators who may be aware of residents' previous experience. Second, we were able to recruit all of our first‐year residents for our pretests and posttests, although 3 did not complete the study in its entirety due to on‐call or post‐call schedules. We were able to obtain detailed assessment of knowledge, performance, and subjective confidence before and after the simulation training on our cohort of residents and were able to demonstrate an improvement in knowledge, skills, and confidence. Furthermore, we were able to demonstrate that benefits in knowledge and confidence were retained at 18 months. Last, we readily implemented our formal CVC curriculum into the existing residency training schedule. It requires a single, 2‐hour session in addition to brief pretest and posttest surveys. It requires minimal equipment, using only 2 CVC mannequins, 4 to 6 central line kits, and an ultrasound machine. The simulation training adheres to and incorporates key elements that have been previously identified as effective teaching tools for simulators: feedback, repetitive practice, and curriculum integration.27 With increasing interest in the use of medical simulation for training and competency assessment in medical education,10 our study provides evidence in support of its use in improving knowledge, skills, and confidence. One of the most important goals of using simulators as an educational tool is to improve patient safety. While assessing for whether or not training on simulators lead to improved patient outcomes is beyond the scope of our study, this question merits further study and should be the focus of future studies.

Conclusions

Training on CVC simulators was associated with an improvement in performance, and increase in knowledge assessment scores and self‐reported confidence in internal medicine residents. Improvement in knowledge and confidence was maintained at 18 months.

The Accreditation Council for Graduate Medical Education mandates that internal medicine residents develop technical proficiency in performing central venous catheterization (CVC).1 Likewise in Canada, technical expertise in performing CVC is a specific competency requirement in the training objectives in internal medicine by the Royal College of Physicians and Surgeons of Canada.2 For certification in Internal Medicine, the American Board of Internal Medicine expects its candidates to be competent with respect to knowledge and understanding of the indications, contraindications, recognition, and management of complications of CVC.3 Despite the importance of procedural teaching in medical education, most internal medicine residency programs do not have formal procedural teaching.4 A number of potential barriers to teaching CVC exist. A recent study by the American College of Physicians found that fewer general internists perform procedures, compared with internists in the 1980s.5 With fewer internists performing procedures, there may be fewer educators with adequate confidence in teaching these procedures.6 Second, with increasing recognition of patient safety, there is a growing reluctance of patients to be used as teaching subjects for those who are learning CVC.7 Not surprisingly, residents report low comfort in performing CVC.8

Teaching procedures on simulators offers the benefits of allowing both teaching and evaluation of procedures without jeopardizing patient safety9 and is a welcomed variation from the traditional see 1, do 1, teach 1 approach.10 Despite the theoretical benefits of the use of simulators in medical education, the efficacy of their use in teaching internal medicine residents remains understudied.

The purpose of our study was to evaluate the benefits of using simulator models in teaching CVC to internal medicine residents. We hypothesized that participation in a simulator‐based teaching session on CVC would result in improved knowledge and performance of the procedure and confidence.

Methods

Results

Of the 33 residents in the first‐year internal medicine program, all consented to participate. Thirty participants (91%) completed the study protocol between January and June 2007. The remaining three residents completed the presession assessments and the simulation session, but did not complete the postsession assessments. These were excluded from our analysis. At baseline, 20 participants had rotated through a previous 1‐month intensive care unit (ICU) block, 8 residents had no prior ICU training, and 2 residents had 2 months of ICU training. Table 1 summarizes the residents' baseline CVC experience prior to the simulation training. In general, participants had limited experience with CVC at baseline, having placed very few internal jugular CVCs (median = 4).

Simulation training was associated with an increase in knowledge. Mean scores on multiple‐choice tests increased from 65.7 11.9% to 81.2 10.7 (P < 0.001). Furthermore, simulation training was associated with improvement in CVC performance. Median global average rating score increased from 3.5 (IQR = 34) to 4.5 (IQR = 44.5) (P < 0.001).

The procedural checklist median score increased from 9 (IQR = 69.5) to 9.5 (IQR = 99.5) (P <.001), median time required for completion of CVC decreased from 8 minutes 22 seconds (IQR = 7 minutes 37 seconds to 12 minutes 1 second) to 6 minutes 43 seconds (IQR = 6 minutes to 7 minutes 25 seconds) (P = 0.002). Other performance measures are summarized in Table 2. Last, simulation training was associated with an increase in self‐rated confidence. The median confidence rating (0 lowest, 5 highest) increased from 3 (moderate, IQR = 23) to 4 (good, IQR = 34) (P < 0.001). The overall satisfaction with the CVC simulation course was good (Table 3) and all 30 participants felt this course should continue to be offered.

Discussion

CVC is an important procedural competency for internists to master. Indications for CVC range from measuring of central venous pressure to administration of specific medications or solutions such as inotropic agents and total parental nutrition. Its use is important in the care of those who are acutely or critically ill and those who are chronically ill. CVC is associated with a number of potentially serious mechanical complications, including arterial puncture, pneumothorax, and death.11, 17 Proficiency in CVC insertion is found to be closely related to operator experience: catheter insertion by physicians who have performed 50 or more CVC are one‐half as likely to sustain complications as catheter insertion by less experienced physicians.18 Furthermore, training has been found to be associated with a decrease in risk for catheter associated infection19 and pneumothorax.20 Therefore, cumulative experience from repeated clinical encounters and education on CVC play an important role in optimizing patient safety and reducing potential errors associated with CVC. It is well‐documented that patients are generally reluctant to allow medical trainees to learn or practice procedures on them,7 especially in the early phases of training. Indeed, close to 50% of internal medicine residents in 1 study reported poor comfort in performing CVCs.8

Deficiencies in procedural teaching in internal medicine residency curriculum have long been recognized.4 Over the past 20 years, there has been a decrease in the percentage of internists who place central lines in practice.5 In the United States, more than 5 million central venous catheters are inserted every year.21 Presumably, concurrent with this trend is an increasing reliance on other specialists such as radiologists or surgical colleagues in the placement of CVCs. Without a concerted effort for medical educators in improving the quality of procedural teaching, this alarming trend is unlikely to be halted.

With the advance of modern technology and medical education, patient simulation offers a new platform for procedural teaching to take place: a way for trainees to practice without jeopardizing patient safety, as well as an opportunity for formal teaching and supervision to occur,9, 22 serving as a welcomed departure from the traditional see 1, do 1, teach 1 model to procedural teaching. While there is data to support the role of simulation teaching in the surgical training programs,16, 23 less objective evidence exists to support its use in internal medicine residency training programs.

Our study supports the use of simulation in training first‐year internal medicine residents in CVC. Our formal curriculum on CVC involving simulation was associated with an increase in knowledge of the procedure, observed procedural performance, and subjective confidence. Furthermore, this improvement in knowledge and confidence was maintained at 18 months. Our study has several limitations, such as those inherent to all studies using the prestudy and poststudy design. Improvement in performance under study may be a result of the Hawthorne effect. We are not able to isolate the effect of self‐directed learning from the benefits from training using simulators. Furthermore, improvement in knowledge and confidence may be a function of time rather than training. However, by not comparing our results to that from a historical cohort, we hope to minimize confounders by having participants serve as their own control. Results from our study would be strengthened by the introduction of a control group and a randomized design. Future study should include a randomized, controlled crossover educational trial. The second limitation of our study is the low interobserver agreement between video raters, indicating only fair to moderate agreement. Although our video raters were trained senior medical residents and faculty members who frequently supervise and evaluate procedures, we did not specifically train them for the purposes of scoring videotaped performances. Further faculty development is needed. Overall, the magnitudes of the interobserver differences were small (mean global rating scale between raters differed by 1 0.9), and may not translate into clinically important differences. Third, competence on performing CVC on simulators has not been directly correlated with clinical competence on real‐life patients, although a previous study on surgical interns suggested that simulator training was associated with clinical competence on real patients.16 Future studies are warranted to investigate the association between educational benefits from simulation and actual error reductions from CVC during patient encounters. Fourth, our study did not examine residents in the use of ultrasound during simulator training. Use of ultrasound devices has been shown to decrease complication rates of CVC insertion24 and increase rates of success,25 and is recommended as the preferred method for insertion of elective internal jugular CVCs.26 However, because our course was introduced during first‐year residency, when majority of the residents have performed fewer than 5 internal jugular CVCs prior to their simulation training session, the objective of our introductory course was to first ensure technical competency by landmark techniques. Once learners have mastered the technical aspect of line insertion, ultrasound‐guided techniques were introduced later in the residency training curriculum. Fifth, only 48% of participants completed the knowledge assessment at 18 months. Selection bias may be present in our long‐term data. However, baseline comparisons between those who completed the 18 month assessment vs. those who did not demonstrated no obvious differences between the 2 groups. Performance was not examined in our long‐term data. Demonstration of retention of psychomotor skills would be reassuring. However, by 18 months, many of our learners had completed a number of procedurally‐intensive rotations. Therefore, because retention of skills could not be reliably attributed to our initial training in the simulator laboratory, the participants were not retested in their performance of the CVC. Future study should include a control group that undergoes delayed training at 18 months to best assess the effect of simulation training on performance. Sixth, only overall confidence in performing CVC was captured. Confidence in each venous access site pretraining and posttraining was not assessed and warrants further study. Last, our study did not document overall costs of delivering the program, including cost of the simulator, facility, supplies, and stipends for teaching faculty. One full‐time equivalent (FTE) staff has previously been estimated to be a requirement for the success of the program.9 Our program required 3 medical educators, all of whom are clinical faculty members, as well as the help of 4 chief medical residents.

Despite our study's limitations, our study has a number of strengths. To our knowledge, our study is the first of its kind examining the use of simulators on CVC procedural performance, with the use of video‐recording, in an independent and blinded manner. Blinding should minimize bias associated with assessments of resident competency by evaluators who may be aware of residents' previous experience. Second, we were able to recruit all of our first‐year residents for our pretests and posttests, although 3 did not complete the study in its entirety due to on‐call or post‐call schedules. We were able to obtain detailed assessment of knowledge, performance, and subjective confidence before and after the simulation training on our cohort of residents and were able to demonstrate an improvement in knowledge, skills, and confidence. Furthermore, we were able to demonstrate that benefits in knowledge and confidence were retained at 18 months. Last, we readily implemented our formal CVC curriculum into the existing residency training schedule. It requires a single, 2‐hour session in addition to brief pretest and posttest surveys. It requires minimal equipment, using only 2 CVC mannequins, 4 to 6 central line kits, and an ultrasound machine. The simulation training adheres to and incorporates key elements that have been previously identified as effective teaching tools for simulators: feedback, repetitive practice, and curriculum integration.27 With increasing interest in the use of medical simulation for training and competency assessment in medical education,10 our study provides evidence in support of its use in improving knowledge, skills, and confidence. One of the most important goals of using simulators as an educational tool is to improve patient safety. While assessing for whether or not training on simulators lead to improved patient outcomes is beyond the scope of our study, this question merits further study and should be the focus of future studies.

Conclusions

Training on CVC simulators was associated with an improvement in performance, and increase in knowledge assessment scores and self‐reported confidence in internal medicine residents. Improvement in knowledge and confidence was maintained at 18 months.

The Accreditation Council for Graduate Medical Education mandates that internal medicine residents develop technical proficiency in performing central venous catheterization (CVC).1 Likewise in Canada, technical expertise in performing CVC is a specific competency requirement in the training objectives in internal medicine by the Royal College of Physicians and Surgeons of Canada.2 For certification in Internal Medicine, the American Board of Internal Medicine expects its candidates to be competent with respect to knowledge and understanding of the indications, contraindications, recognition, and management of complications of CVC.3 Despite the importance of procedural teaching in medical education, most internal medicine residency programs do not have formal procedural teaching.4 A number of potential barriers to teaching CVC exist. A recent study by the American College of Physicians found that fewer general internists perform procedures, compared with internists in the 1980s.5 With fewer internists performing procedures, there may be fewer educators with adequate confidence in teaching these procedures.6 Second, with increasing recognition of patient safety, there is a growing reluctance of patients to be used as teaching subjects for those who are learning CVC.7 Not surprisingly, residents report low comfort in performing CVC.8

Teaching procedures on simulators offers the benefits of allowing both teaching and evaluation of procedures without jeopardizing patient safety9 and is a welcomed variation from the traditional see 1, do 1, teach 1 approach.10 Despite the theoretical benefits of the use of simulators in medical education, the efficacy of their use in teaching internal medicine residents remains understudied.

The purpose of our study was to evaluate the benefits of using simulator models in teaching CVC to internal medicine residents. We hypothesized that participation in a simulator‐based teaching session on CVC would result in improved knowledge and performance of the procedure and confidence.

Methods

Results

Of the 33 residents in the first‐year internal medicine program, all consented to participate. Thirty participants (91%) completed the study protocol between January and June 2007. The remaining three residents completed the presession assessments and the simulation session, but did not complete the postsession assessments. These were excluded from our analysis. At baseline, 20 participants had rotated through a previous 1‐month intensive care unit (ICU) block, 8 residents had no prior ICU training, and 2 residents had 2 months of ICU training. Table 1 summarizes the residents' baseline CVC experience prior to the simulation training. In general, participants had limited experience with CVC at baseline, having placed very few internal jugular CVCs (median = 4).

Simulation training was associated with an increase in knowledge. Mean scores on multiple‐choice tests increased from 65.7 11.9% to 81.2 10.7 (P < 0.001). Furthermore, simulation training was associated with improvement in CVC performance. Median global average rating score increased from 3.5 (IQR = 34) to 4.5 (IQR = 44.5) (P < 0.001).

The procedural checklist median score increased from 9 (IQR = 69.5) to 9.5 (IQR = 99.5) (P <.001), median time required for completion of CVC decreased from 8 minutes 22 seconds (IQR = 7 minutes 37 seconds to 12 minutes 1 second) to 6 minutes 43 seconds (IQR = 6 minutes to 7 minutes 25 seconds) (P = 0.002). Other performance measures are summarized in Table 2. Last, simulation training was associated with an increase in self‐rated confidence. The median confidence rating (0 lowest, 5 highest) increased from 3 (moderate, IQR = 23) to 4 (good, IQR = 34) (P < 0.001). The overall satisfaction with the CVC simulation course was good (Table 3) and all 30 participants felt this course should continue to be offered.

Discussion

CVC is an important procedural competency for internists to master. Indications for CVC range from measuring of central venous pressure to administration of specific medications or solutions such as inotropic agents and total parental nutrition. Its use is important in the care of those who are acutely or critically ill and those who are chronically ill. CVC is associated with a number of potentially serious mechanical complications, including arterial puncture, pneumothorax, and death.11, 17 Proficiency in CVC insertion is found to be closely related to operator experience: catheter insertion by physicians who have performed 50 or more CVC are one‐half as likely to sustain complications as catheter insertion by less experienced physicians.18 Furthermore, training has been found to be associated with a decrease in risk for catheter associated infection19 and pneumothorax.20 Therefore, cumulative experience from repeated clinical encounters and education on CVC play an important role in optimizing patient safety and reducing potential errors associated with CVC. It is well‐documented that patients are generally reluctant to allow medical trainees to learn or practice procedures on them,7 especially in the early phases of training. Indeed, close to 50% of internal medicine residents in 1 study reported poor comfort in performing CVCs.8

Deficiencies in procedural teaching in internal medicine residency curriculum have long been recognized.4 Over the past 20 years, there has been a decrease in the percentage of internists who place central lines in practice.5 In the United States, more than 5 million central venous catheters are inserted every year.21 Presumably, concurrent with this trend is an increasing reliance on other specialists such as radiologists or surgical colleagues in the placement of CVCs. Without a concerted effort for medical educators in improving the quality of procedural teaching, this alarming trend is unlikely to be halted.

With the advance of modern technology and medical education, patient simulation offers a new platform for procedural teaching to take place: a way for trainees to practice without jeopardizing patient safety, as well as an opportunity for formal teaching and supervision to occur,9, 22 serving as a welcomed departure from the traditional see 1, do 1, teach 1 model to procedural teaching. While there is data to support the role of simulation teaching in the surgical training programs,16, 23 less objective evidence exists to support its use in internal medicine residency training programs.

Our study supports the use of simulation in training first‐year internal medicine residents in CVC. Our formal curriculum on CVC involving simulation was associated with an increase in knowledge of the procedure, observed procedural performance, and subjective confidence. Furthermore, this improvement in knowledge and confidence was maintained at 18 months. Our study has several limitations, such as those inherent to all studies using the prestudy and poststudy design. Improvement in performance under study may be a result of the Hawthorne effect. We are not able to isolate the effect of self‐directed learning from the benefits from training using simulators. Furthermore, improvement in knowledge and confidence may be a function of time rather than training. However, by not comparing our results to that from a historical cohort, we hope to minimize confounders by having participants serve as their own control. Results from our study would be strengthened by the introduction of a control group and a randomized design. Future study should include a randomized, controlled crossover educational trial. The second limitation of our study is the low interobserver agreement between video raters, indicating only fair to moderate agreement. Although our video raters were trained senior medical residents and faculty members who frequently supervise and evaluate procedures, we did not specifically train them for the purposes of scoring videotaped performances. Further faculty development is needed. Overall, the magnitudes of the interobserver differences were small (mean global rating scale between raters differed by 1 0.9), and may not translate into clinically important differences. Third, competence on performing CVC on simulators has not been directly correlated with clinical competence on real‐life patients, although a previous study on surgical interns suggested that simulator training was associated with clinical competence on real patients.16 Future studies are warranted to investigate the association between educational benefits from simulation and actual error reductions from CVC during patient encounters. Fourth, our study did not examine residents in the use of ultrasound during simulator training. Use of ultrasound devices has been shown to decrease complication rates of CVC insertion24 and increase rates of success,25 and is recommended as the preferred method for insertion of elective internal jugular CVCs.26 However, because our course was introduced during first‐year residency, when majority of the residents have performed fewer than 5 internal jugular CVCs prior to their simulation training session, the objective of our introductory course was to first ensure technical competency by landmark techniques. Once learners have mastered the technical aspect of line insertion, ultrasound‐guided techniques were introduced later in the residency training curriculum. Fifth, only 48% of participants completed the knowledge assessment at 18 months. Selection bias may be present in our long‐term data. However, baseline comparisons between those who completed the 18 month assessment vs. those who did not demonstrated no obvious differences between the 2 groups. Performance was not examined in our long‐term data. Demonstration of retention of psychomotor skills would be reassuring. However, by 18 months, many of our learners had completed a number of procedurally‐intensive rotations. Therefore, because retention of skills could not be reliably attributed to our initial training in the simulator laboratory, the participants were not retested in their performance of the CVC. Future study should include a control group that undergoes delayed training at 18 months to best assess the effect of simulation training on performance. Sixth, only overall confidence in performing CVC was captured. Confidence in each venous access site pretraining and posttraining was not assessed and warrants further study. Last, our study did not document overall costs of delivering the program, including cost of the simulator, facility, supplies, and stipends for teaching faculty. One full‐time equivalent (FTE) staff has previously been estimated to be a requirement for the success of the program.9 Our program required 3 medical educators, all of whom are clinical faculty members, as well as the help of 4 chief medical residents.

Despite our study's limitations, our study has a number of strengths. To our knowledge, our study is the first of its kind examining the use of simulators on CVC procedural performance, with the use of video‐recording, in an independent and blinded manner. Blinding should minimize bias associated with assessments of resident competency by evaluators who may be aware of residents' previous experience. Second, we were able to recruit all of our first‐year residents for our pretests and posttests, although 3 did not complete the study in its entirety due to on‐call or post‐call schedules. We were able to obtain detailed assessment of knowledge, performance, and subjective confidence before and after the simulation training on our cohort of residents and were able to demonstrate an improvement in knowledge, skills, and confidence. Furthermore, we were able to demonstrate that benefits in knowledge and confidence were retained at 18 months. Last, we readily implemented our formal CVC curriculum into the existing residency training schedule. It requires a single, 2‐hour session in addition to brief pretest and posttest surveys. It requires minimal equipment, using only 2 CVC mannequins, 4 to 6 central line kits, and an ultrasound machine. The simulation training adheres to and incorporates key elements that have been previously identified as effective teaching tools for simulators: feedback, repetitive practice, and curriculum integration.27 With increasing interest in the use of medical simulation for training and competency assessment in medical education,10 our study provides evidence in support of its use in improving knowledge, skills, and confidence. One of the most important goals of using simulators as an educational tool is to improve patient safety. While assessing for whether or not training on simulators lead to improved patient outcomes is beyond the scope of our study, this question merits further study and should be the focus of future studies.

Conclusions

Training on CVC simulators was associated with an improvement in performance, and increase in knowledge assessment scores and self‐reported confidence in internal medicine residents. Improvement in knowledge and confidence was maintained at 18 months.

The benefits of glycemic control include decreased patient morbidity, mortality, length of stay, and reduced hospital costs. In 2004, the American College of Endocrinology (ACE) issued glycemic guidelines for non‐critical‐care units (fasting glucose <110 mg/dL, nonfasting glucose <180 mg/dL).1 A comprehensive review of inpatient glycemic management called for development and evaluation of inpatient programs and tools.2 The 2006 ACE/American Diabetes Association (ADA) Statement on Inpatient Diabetes and Glycemic Control identified key components of an inpatient glycemic control program as: (1) solid administrative support; (2) a multidisciplinary committee; (3) assessment of current processes, care, and barriers; (4) development and implementation of order sets, protocols, policies, and educational efforts; and (5) metrics for evaluation.3

In 2003, Harborview Medical Center (HMC) formed a multidisciplinary committee to institute a Glycemic Control Program. The early goals were to decrease the use of sliding‐scale insulin, increase the appropriate use of basal and prandial insulin, and to avoid hypoglycemia. Here we report our program design and trends in physician insulin ordering from 2003 through 2006.

Patients and Methods

Program Description

Since 2003, the multidisciplinary committeephysicians, nurses, pharmacy representatives, and dietary and administrative representativeshas directed the development of the Glycemic Control Program with support from hospital administration and the Department of Quality Improvement. Funding for this program has been provided by the hospital based on the prominence of glycemic control among quality and safety measures, a projected decrease in costs, and the high incidence of diabetes in our patient population. Figure 1 outlines the program's key interventions.

Figure 1

First, a Subcutaneous Insulin Order Form was released for elective use in May 2004 (Figure 2). This form incorporated the 3 components of quality insulin ordering (basal, scheduled prandial, and prandial correction dosing) and provides prompts and education. A Diabetes Nurse Specialist trained nursing staff on the use of the form.

Figure 2

Second, we developed an automated daily data report identifying patients with out‐of‐range glucose levels defined as having any single glucose readings <60 mg/dL or any 2 readings 180 mg/dL within the prior 24 hours. In February 2006, this daily report became available to the clinicians on the committee.

Third, the Glycemic Control Program recruited a full‐time clinical Advanced Registered Nurse Practitioner (ARNP) and part‐time supervising physician to provide directed intervention and education for patients and medical personnel. Since August 2006, the ARNP has reviewed the out‐of‐range report daily, performs assessments, refines insulin orders, and educates clinicians. The assessments include chart review (of history and glycemic control), discussion with primary physician and nurse (and often the dietician), and interview of the patient and/or family. This leads to development and implementation of a glycemic control plan. Clinician education is performed both as direct education of the primary physician at the time of intervention and as didactic sessions.

Results

Physician Insulin Ordering

Ordering of both short‐acting and basal insulin increased (Figure 3). The ratio of short‐acting to basal orders decreased from 3.36 (1668/496) in 2003 to 1.97 (2226/1128) in 2006.

Figure 3

Chart review of the 100 randomly selected dysglycemic patients revealed increased ordering of prandial correction dosing from 8% of patients in 2003 to 32% in 2006. Yet, only 1 patient in 2003 and only 2 in 2006 had scheduled prandial. Ordering of sliding scale insulin fell from 16% in 2003 to 4% in 2006.

Glycemic Control Outcomes

The percentage of dysglycemic patients with hyperglycemia ranged from 19 to 24 without significant decline over the 4 years (Figure 4A). The percentage of hypoglycemic dysglycemic patients was increasing from 2003 to 2004, but in the years following the interventions (2005 through 2006) this declined significantly (P = 0.003; Figure 4B). On average, the observed LOS was higher for dysglycemic vs. euglycemic patients (mean SD days: 9.4 12.2 and 5.8 8.5, respectively). The mean observed to expected mortality ratio was 0.45 0.08 and 0.44 0.17 for the dysglycemic and euglycemic patients, respectively. Over the 4 years no statistically significant change in observed LOS or adjusted mortality was found (data not shown).

Figure 4

Conclusions

HMC, a safety net hospital with the highest UHC expected mortality of 131 hospitals nationwide, has demonstrated early successes in building its Glycemic Control Program, including: (1) decreased prescription of sliding scale; (2) a marked increase in prescription of basal insulin; and (3) significantly decreasing hypoglycemic events subsequent to the interventions. The decreased sliding scale and increased overall ordering of insulin could reflect increased awareness brought internationally through the literature and locally through our program. Two distinctive aspects of HMC's Glycemic Control Program, when compared to others,68 include: (1) the daily use of real‐time data to identify and target patients with out‐of‐range glucose levels; and (2) the coverage of all non‐critical‐care floors with a single clinician.

In 2003 and 2004, the increasing hypoglycemia we observed paralleled the international focus on aggressively treating hyperglycemia in the acute care setting. We observed a significant decrease in hypoglycemia in 2005 and 2006 that could be attributed to the education provided by the Glycemic Control Program and 2 features on the subcutaneous insulin order set: the prominent hypoglycemia protocol and the order hold prandial insulin if the patient cannot eat. These are similar features identified in a report on preventing hospital hypoglycemia.9 Additionally, hypoglycemia may have decreased secondary to the emphasis on not using short‐acting insulin at bedtime.

Despite increased and improved insulin ordering, we did not observe a significant change in the percent of dysglycemic patients with 2 glucose levels 180 mg/dL. In our program patients are identified for intervention after their glucose levels are out‐of‐range. To better evaluate the impact of our interventions on the glycemic control of each patient, we plan to analyze the glucose levels in the days following identification of patients. Alternatively, we could provide intervention to all patients with dysglycemia rather than waiting for glucoses to be out‐of‐range. Though this approach would require greater resources than the single clinician we currently employ.

Our early experience highlights areas for future evaluation and intervention. First, the lack of scheduled prandial insulin and that less than one‐third of dysglycemic patients have basal insulin ordered underscore a continued need to target quality insulin ordering to include all componentsbasal, scheduled prandial, and prandial correction. Second, while the daily report is a good rudimentary identification tool for at‐risk patients, it offers limited information as to the impact of our clinical intervention. Thus, refined evaluative metrics need be developed to prospectively assess the course of glycemic control for patients.

We acknowledge the limitations of this study. First, our most involved interventionthe addition of the clinical intervention teamcame only 6 months before the end of the study period. Second, this is an observational retrospective analysis and cannot distinguish confounders, such as physician preferences and decisions, that not easily quantified or controlled for. Third, our definition of dysglycemic incorporated 41% of non‐critical‐care patients, possibly reflecting too broad a definition.

In summary, we have described an inpatient Glycemic Control Program that relies on real‐time data to identify patients in need of intervention. Early in our program we observed improved insulin ordering quality and decreased rates of hypoglycemia. Future steps include evaluating the impact of our clinical intervention team and further refining glycemic control metrics to prospectively identify patients at risk for hyper‐ and hypoglycemia.