In 1996, the regional anesthesia team at Duke University Health System initiated a new model for resident training in regional anesthesia. Our primary objective was to increase resident training and exposure to peripheral nerve blocks (PNBs) with a resultant improvement in skill and confidence level. This objective had to be achieved with consideration of the shortage of anesthesia work force, especially regional anesthesiologists.
Recent publications have emphasized the paucity of opportunities for anesthesia residents to learn PNB (1,2). In 1999, Smith et al. (1) assessed the number of regional blocks performed by residents and the residents’ confidence levels. Disturbingly, third-year residents (CA-3) had performed on average <10 of each of the following regional procedures: thoracic epidurals, interscalene, femoral, sciatic, ankle, and IV regional anesthetics. More than 50% of CA-3 residents stated they were not confident in performing interscalene, femoral, and sciatic PNBs. Kopacz and Neal (2) determined the number of regional anesthesia techniques performed by residents by using the annual training report forms submitted to the Residency Review Committee (RRC) for Anesthesiology for the 1999 to 2000 academic year. The median number of cumulative spinal, epidural, and PNBs performed by CA-3 residents were 94, 175, and 45, respectively. In a previous publication, Kopacz et al. (3) postulated that 45 spinal and 85 epidural attempts were necessary to achieve a 90% success rate. Thus, training in central neuraxial techniques seems to be adequate. The number of attempts needed to achieve proficiency in nerve blocks such as interscalene, supraclavicular, lumbar plexus, and sciatic has not been determined, but if an assumption of numbers similar to that for neuraxial blocks is made, the studies by Smith et al. (1) and Kopacz and Neal (2) demonstrate that the number of PNBs performed by residents nationwide is inadequate.
We assessed the success of our new model by comparing the data supplied by the Anesthesiology Residency Program to the RCC for the training period encompassing the academic years from July 1992 to June 1995 (pre-model) compared with the data from the academic years July 1998 to June 2001 (post-model). These data reflect the entirety of the regional anesthesia experience during residency training for the indicated years.
The process of developing a regional anesthesia training program began in 1996 with the establishment of a hospital working committee. The principal intent of this committee was to improve patient care and operating room (OR) efficiency by shortening OR turnover, and providing better postoperative analgesia using regional anesthesia. A secondary but equally important goal was to improve the training of our residents in regional anesthesia.
The model approved by the hospital committee was the use of CA-3 residents to perform the PNB in the preoperative area under the supervision of multiple faculty. Several changes in the department and our OR structure were required to achieve this goal. The development of a fully equipped preoperative area to safely and effectively facilitate regional anesthesia procedures with full monitoring, oxygen supplementation, and access to drugs and resuscitative equipment in each bed space was critical to achieve this goal. This allowed the placement of PNB in the preoperative area, thus positively impacting turnover. Next, we had to ensure an adequate number of faculty trained in regional anesthesia to maintain continuous faculty supervision of our residents while performing PNB. In a typical week, we have an average of 3 or 4 CA-1 residents and 1 or 2 CA-3 residents rotating through our orthopedic and regional anesthesia division. Our division covers 6 to 8 ORs on a daily basis. Faculty were cross-trained, thus increasing our numbers in the regional group from two to eight anesthesiologists. Cross-training new faculty members involved relieving these individuals from their regular OR duties and having them perform PNBs in the preoperative blocking area under the supervision of other regional anesthesiologists. This clinical training was further strengthened by didactic courses consisting of a lecture series, participation in regional anesthesia workshops, and studying the divisional regional anesthesia manual as well as other suggested texts. The training period required 3–6 mo for the completely inexperienced faculty to become proficient in PNB. Subsequently, the schedules of our residents were altered by adding a dedicated regional anesthesia training block period in the final year. A period of 2–3 mo was allotted for each CA-3 resident to allow every resident the opportunity to participate in this regional block period and at the same time allow each resident to perform a sufficient number of cases. The role of the resident in the preoperative area was to assess patients, perform PNB under the supervision of faculty members, and assist CA-1 or CA-2 residents who were assigned to ORs to perform blocks on their patients. The assistance consisted of preparing the patients and equipment so that the junior residents could perform the PNB in the preoperative block area as soon as their previous case was completed. The CA-3 resident would not perform blocks on patients who were assigned to other residents, but only on cases assigned to ORs with certified registered nurse anesthetists, which permitted the CA-1 and CA-2 residents early exposure to regional anesthesia techniques.
We assessed the success of our new teaching model by comparing the data supplied by the Anesthesia Residency Program to the RCC for Anesthesiology for the training period July 1992–June 1995 (pre-model) with the data for the training period July 1998–June 2001 (post-model). We also wanted to examine the variety of PNBs performed by our CA-3 residents who had spent their entire residency under the new model. A questionnaire was sent to all CA-3 residents in April 2001, 2 mo before the completion of the CA-3 residency-training program. All residents maintained accurate records by using logbooks or a personal digital assistant. The regional anesthesia techniques assessed in the survey included spinal, lumbar epidurals, thoracic epidurals, interscalene, supraclavicular, axillary, sciatic, femoral, lumbar plexus, IV regional, ankle, and paravertebral blockade.
The data were reported as median with interquartile range. The distribution of the data were tested for normality by using the Shapiro-Wilk test of normality. Two-sample t-tests or two-sample Wilcoxon’s ranked sum test were used to evaluate the difference in the number of blocks before and after the teaching model at each year of residency and for the total number of blocks in all 3 yr. A mixed-method methodology was used to account for the within-subject correlation during the 3 yr. Bonferroni correction was used to correct the error rate for the tests at each year in which statistical significance was achieved at the 0.0167 level.
The number of regional blocks performed by the pre-model anesthesia residents (1992–1995) (n = 12) and the post-model anesthesia residents (1998–2001) (n = 10) are shown in Table 1. The cumulative number of PNBs performed by the pre-model residents during their 3 yr of training was 80 (58–105) compared with the post-model residents who performed 350 (237–407) PNBs during the equivalent training period. This difference was highly significant with a P value < 0.0001. At each of the 3 yr of training, the post-model residents performed significantly more PNBs than the pre-model residents (P < 0.005), with the largest difference demonstrated in the last year of training (P < 0.0003) (Table 1;Fig. 1, A).
Overall, significantly more spinals and epidurals were performed by the post-model residents than pre-model residents (P < 0.001 and P < 0.01, respectively). However, unlike PNB, there was only a significant difference in the first year of training (P < 0.0003) (Table 1;Fig. 1, B and C).
The mixed-model results echoed what is described in Figure 1, A–C. Mixed models were fitted to study the relationship of each of the three different blocks as a function of an indicator for pre-post training data, year of training, and their interaction. The interactions were significant for all 3 responses (P < 0.007 for spinals, P < 0.024 for epidurals, and P < 0.0002 for PNB). Inference on the main effects of the training model cannot be done when analyzing all years collectively because of this significant interaction. Instead, inference on the difference between pre- and post-training model data can be measured at each year and for the total number of blocks performed.
Six of 10 post-model CA-3 residents completed the survey evaluating the variety of regional anesthetics performed. The types of PNBs performed by the post-model CA-3 residents are presented in Figure 2.
Our new regional training model dramatically increased the cumulative number of PNBs performed by our residents during their 3-year training period from 80 (58–105) to 350 (237–407) (P < 0.0003) (Table 1). This increase in PNBs has not come at the price of decreased training in spinals or epidurals. In fact, there was an increase in the cumulative numbers of spinals and epidurals performed since the introduction of the new training model (P < 0.006).
CA-3 residents in the surveys conducted by Smith et al. (1) and Kopacz and Neal (2) performed 34 and 45 PNBs, respectively, during their 3-year training period compared with 350 PNBs performed by post-model CA-3 residents at our institution (Fig. 3). The RRC for Anesthesiology has established a minimal requirement for PNBs for surgical procedures at 40 (4). These are minimal requirements, and the number of PNBs to be performed by residents to acquire efficiency has not been extensively reported. Konrad et al. (5) found that 20 axillary blocks had to be performed to achieve a success rate of 70%. Our residents performed an average of 40 axillary blocks, twice the number required to reach a 70% competency rate (Fig. 2). This number could have been much larger but many upper-limb procedures at our institution are performed under supraclavicular, infraclavicular, and interscalene blockade. The average number of supraclavicular blocks and interscalene blocks performed by our residents was 19 and 22 (Fig. 2). Our total PNB numbers are much larger than the national averages (1,2) and we believe that our residents complete anesthesia residency training having sufficient skills to perform these PNBs in their continuing practice. Hadzic et al. (6) reported that anesthesiologists who rated their training in PNB to be adequate devoted a larger percentage of their practice to PNB than anesthesiologists who rated their training as inadequate.
The teaching model has resulted in an increase in the number of PNBs and also a greater diversity in the type of PNB performed by our CA-3 residents (Fig. 2). Of a total of 77 brachial plexus blocks, 27% were interscalene, 24% supraclavicular, and 48% were axillary. This is compared to 83% usage of the axillary approach to the brachial plexus as reported by Smith et al. (1). Our CA-3 residents performed an average of 87 lumbar plexus blocks and 56 paravertebral blocks during their training. These blocks were not considered in the national survey by Smith et al. (1). The number of ankle PNBs and IV regional blocks performed by our residents was not significantly different from national averages (1). The number of spinals and epidurals was similar between our institution and the national averages (Fig. 3). The averages at our institution exceeded the 45 spinal and 85 epidurals needed to obtain 90% efficiency as reported by Kopacz et al. (3) as did the national averages (1,2). Therefore, resident training in neuraxial blocks seems to be adequate in United States residency programs.
Another important feature of our new model is that the junior residents, in particular our first-year residents, gained experience in performing PNB (Table 1). Although the major influence of this teaching model was on the CA-3 training year, there was also a significant positive effect on the CA-1 training year (Table 1, Fig. 1, A). The new training model therefore improved resident experience at both the CA-1 and CA-3 levels. CA-1 residents performed an average of 50 PNBs during their first year compared with the national average of 14 during the same training period (2). CA-2 residents performed 27 PNBs compared with the national average of 13 (2). CA-2 residents spend a large percentage of their time in rotations without much emphasis in regional anesthesia and this was unchanged by the new teaching model. CA-3 residents facilitated the process by assessing the patients for junior residents and often assisted the junior residents in preparing the necessary equipment and monitoring for the next case. This not only expedited turnover but also permitted more time for faculty to teach residents.
In developing this new model, we considered two other models. The first alternative model considered was to use one faculty member to be solely responsible for providing a regional anesthesia service in the preoperative area for the entire OR system. A second alternative model involved the use of one certified registered nurse anesthetist employed to assist all faculty members in performing the blocks in the preoperative area. Both of these models would have resulted in benefits to patient care, but neither of these models would have resulted in improved resident training. For this reason, we adopted the model of using a CA-3 resident in the preoperative block area because this addressed both of our goals of improved patient care and resident training.
In assessing the success of our regional teaching model, we have relied solely on quantitative numbers as a measure of adequacy of resident training. This may not be a true reflection of the ability of the resident to gain mastery of the regional technique (7). We need to develop other methods of resident assessment in addition to our present reporting of numbers to the RRC. This may include the use of an observational structured clinical examination to demonstrate resident ability to perform regional techniques successfully and safely. The use of either animal models or training simulators may offer qualitative methods of assessing resident performance. Videotaping as recently reported by Birnbach et al. (8) may be useful in training as well as evaluation of the resident. Qualitative methods of evaluating residents are probably of even more importance in those residency-training programs in which the number of opportunities for performing regional techniques is small. Consideration of evaluation methods other than numbers performed may help programs determine that their educational process for regional anesthesia is providing the desired outcome, i.e., graduates who are competent and confident in using regional anesthetics in their post-residency practice. This is also consistent with the Accreditation Council for Graduate Medical Education plan to assess the outcome, rather than process, of resident education (9).
The regional anesthesia division has strived to further refine the regional anesthesia teaching model. One of the divisional faculty has developed the human anatomical laboratory experience to allow the residents hands-on demonstrations of the relevant neurologic and vascular anatomy. A multimedia library of commercial CD-ROMs demonstrating many PNBs is readily available at computer sites within the hospital. In addition, an institutional web page is currently under development, which will be available through the computerized anesthetic record database system (Saturn®) located in each OR and preoperative block area. The regional anesthesia faculty is in the process of developing a simulator model to help familiarize residents with complications of regional anesthesia such as inadvertent IV injection and total spinal physiology. An additional aspect in the evolution of our training model will be inclusion of upper airway regional techniques to facilitate awake fiberoptic intubations.
In conclusion, a new regional anesthesia teaching model has been used since 1996. The new model has increased the residents’ exposure to all regional anesthesia techniques, but particularly PNBs.
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9. ACGME Outcome Project. 2000. Accreditation Council for Graduate Medical Education Website. Available at http://www.acgme.org.