Susan M. Martinelli

A systematic review of the effectiveness of flipped classrooms in medical education

There are inconsistent claims made about the effectiveness of the flipped classroom (FC) in medical education; however, the quality of the empirical evidence used to back up these claims is not evident. The aims of this review are to examine the scope and quality of studies on the FC teaching approach in medical education and to assess the effects of FCs on medical learning.

Simulator training enhances resident performance in transesophageal echocardiography.

Background:Standardized training via simulation as an educational adjunct may lead to a more rapid and complete skill achievement. The authors hypothesized that simulation training will also enhance performance in transesophageal echocardiography image acquisition among anesthesia residents. Methods:A total of 42 clinical anesthesia residents were randomized to one of two groups: a control group, which received traditional didactic training, and a simulator group, whose training used a transesophageal echocardiography–mannequin simulator. Each participating resident was directed to obtain 10 commonly used standard views on an anesthetized patient under attending supervision. Each of the 10 selected echocardiographic views were evaluated on a grading scale of 0 to 10, according to predetermined criteria. The effect of the intervention was assessed by using a linear mixed model implemented in SAS 9.3 (SAS Institute Inc., Cary, NC). Results:Residents in the simulation group obtained significantly higher-quality images with a mean total image quality score of 83 (95% CI, 74 to 92) versus the control group score of 67 (95% CI, 58 to 76); P = 0.016. On average, 71% (95% CI, 58 to 85) of images acquired by each resident in the simulator group were acceptable for clinical use compared with 48% (95% CI, 35 to 62) in the control; P = 0.021. Additionally, the mean difference in score between training groups was the greatest for the clinical anesthesia-1 residents (difference 24; P = 0.031; n = 7 per group) and for those with no previous transesophageal echocardiography experience (difference 26; P = 0.005; simulator n = 13; control n = 11). Conclusion:Simulation-based transesophageal echocardiography education enhances image acquisition skills in anesthesiology residents.

Trends in cardiac surgery-associated acute renal failure in the United States: A disproportionate increase after heart transplantation

Acute renal failure (ARF) is common after cardiac surgery and more frequent after complex cardiac surgery. While the incidence of ARF is increasing after coronary artery bypass graft (CABG) surgery, trends in other forms of cardiac surgery remain unclear. We investigated the trend of ARF in various cardiac procedures and compared patterns using CABG surgery as a reference group. The study population consisted of discharges from the Nationwide Inpatient Sample from 1988 to 2003, grouped according to surgery as: CABG, CABG with mitral valve, CABG with other valve, valve alone, and heart transplant. Standard diagnostic codes were used to identify ARF among discharges. Multivariable regression was used to determine trends in ARF among various procedures with CABG as a reference group. The incidence of ARF increased in all five groups (p < 0.001) over the 16-year period. The ARF incidence was highest in the heart transplant group (17%). Compared to the CABG population, patients following heart transplantation developed ARF at higher rates during the study period. In contrast, while ARF increased over time in other groups, the rates of rise were slower than in CABG patients. Among heart surgery procedures, ARF incidence is highest in heart transplantation. The incidence of ARF is also increasing at a faster rate in this group of patients in contrast to other procedure groups when compared to CABG surgery. The disproportionate increase in ARF burden after heart transplantation is a concern due to its strong association with chronic kidney disease and mortality.

Intraoperative transesophageal echocardiography diagnosis of residual tumor fragment after surgical removal of renal cell carcinoma

A 65-year-old male presented with hematuria secondary to a 10-cm renal cell carcinoma. A magnetic resonance scan demonstrated tumor extension into the left renal vein and the inferior vena cava (IVC) up to the level of the hepatic venous confluence. Imaging studies revealed no evidence of metastatic disease. Therefore, he was considered a candidate for radical nephrectomy and tumor thrombectomy. After induction of general anesthesia, the patient was positioned supine and underwent a bilateral anterior subcostal incision. Cardiopulmonary bypass was not considered necessary for this procedure as there was no atrial involvement demonstrated on preoperative imaging. The surgeons requested intraoperative transesophageal echocardiography (TEE) for confirming and monitoring the extent of tumor thrombus. TEE was performed using a multiplane, phased array TEE probe (T6210 Omniplane II transducer, Phillips Medical Systems, Andover, MA). Images were digitally acquired on a Phillips Sonos 7500 Ultrasound Imaging System (Phillips Medical Systems, Andover, MA). Initial examination of the heart confirmed normal cardiac structures and function without a patent foramen ovale. The tumor was well visualized in the IVC distal to the hepatic vein-IVC confluence approximately 6 to 8 cm from the IVCright atrial junction (Fig. 1 and Video clip 1; please see video clip available at www.anesthesia-analgesia.org) without involvement of the heart or pulmonary circulation. The surgery was technically difficult, with significant blood loss. At the completion of the nephrectomy and thrombectomy, the TEE examination revealed residual fragments in the IVC (Fig. 2 and Video clip 2; please see video clip available at www. anesthesia-analgesia.org). These fragments were mobile echogenic masses located in the area where the tumor thrombus was previously identified. This finding was discussed with the surgeons who determined that surgical re-exploration was not indicated and that an IVC filter was the most appropriate next step. The vascular radiology team was consulted and the patient was taken directly to the radiology suite while still anesthetized. The radiologists easily placed an OptEase IVC Filter (Cordis Warren, NJ). The patient had an uneventful postoperative course and was discharged home on the eighth postoperative day.

Platelet Counts and Postoperative Stroke after Coronary Artery Bypass Grafting Surgery

BACKGROUND: Declining platelet counts may reveal platelet activation and aggregation in a postoperative prothrombotic state. Therefore, we hypothesized that nadir platelet counts after on-pump coronary artery bypass grafting (CABG) surgery are associated with stroke. METHODS: We evaluated 6130 adult CABG surgery patients. Postoperative platelet counts were evaluated as continuous and categorical (mild versus moderate to severe) predictors of stroke. Extended Cox proportional hazard regression analysis with a time-varying covariate for daily minimum postoperative platelet count assessed the association of day-to-day variations in postoperative platelet count with time to stroke. Competing risks proportional hazard regression models examined associations between day-to-day variations in postoperative platelet counts with timing of stroke (early: 0–1 days; delayed: ≥2 days). RESULTS: Median (interquartile range) postoperative nadir platelet counts were 123.0 (98.0–155.0) × 109/L. The incidences of postoperative stroke were 1.09%, 1.50%, and 3.02% for platelet counts >150 × 109/L, 100 to 150 × 109/L, and <100 × 109/L, respectively. The risk for stroke increased by 12% on a given postoperative day for every 30 × 109/L decrease in platelet counts (adjusted hazard ratio [HR], 1.12; 95% confidence interval [CI], 1.01–1.24; P= .0255). On a given day, patients with moderate to severe thrombocytopenia were almost twice as likely to develop stroke (adjusted HR, 1.89; 95% CI, 1.13–3.16; P= .0155) as patients with nadir platelet counts >150 × 109/L. Importantly, such thrombocytopenia, defined as a time-varying covariate, was significantly associated with delayed (≥2 days after surgery; adjusted HR, 2.83; 95% CI, 1.48–5.41; P= .0017) but not early postoperative stroke. CONCLUSIONS: Our findings suggest an independent association between moderate to severe postoperative thrombocytopenia and postoperative stroke, and timing of stroke after CABG surgery.

Results of a Flipped Classroom Teaching Approach in Anesthesiology Residents

BACKGROUND In a flipped classroom approach, learners view educational content prior to class and engage in active learning during didactic sessions. OBJECTIVE We hypothesized that a flipped classroom improves knowledge acquisition and retention for residents compared to traditional lecture, and that residents prefer this approach. METHODS We completed 2 iterations of a study in 2014 and 2015. Institutions were assigned to either flipped classroom or traditional lecture for 4 weekly sessions. The flipped classroom consisted of reviewing a 15-minute video, followed by 45-minute in-class interactive sessions with audience response questions, think-pair-share questions, and case discussions. The traditional lecture approach consisted of a 55-minute lecture given by faculty with 5 minutes for questions. Residents completed 3 knowledge tests (pretest, posttest, and 4-month retention) and surveys of their perceptions of the didactic sessions. A linear mixed model was used to compare the effect of both formats on knowledge acquisition and retention. RESULTS Of 182 eligible postgraduate year 2 anesthesiology residents, 155 (85%) participated in the entire intervention, and 142 (78%) completed all tests. The flipped classroom approach improved knowledge retention after 4 months (adjusted mean = 6%; P = .014; d = 0.56), and residents preferred the flipped classroom (pre = 46%; post = 82%; P < .001). CONCLUSIONS The flipped classroom approach to didactic education resulted in a small improvement in knowledge retention and was preferred by anesthesiology residents.

Combined Aortic Valve Replacement and Renal Cell Carcinoma Thrombectomy.

Although nephrectomy for renal cell carcinoma with inferior vena cava invasion is a common procedure, it is rare to have level IV invasion necessitating cardiopulmonary bypass (CPB). Furthermore, it is exceptionally rare to perform cardiac surgery concomitantly with this resection. We report a case in which an aortic valve replacement was done in the same surgical setting as a level IV thrombectomy. We have demonstrated that although it can be difficult to manage the coagulopathy post-CPB, this can be successfully accomplished with adequate prior preparation and a coordinated team effort.

Echocardiographic discovery of doubled interatrial septum: An incidental finding

A double-walled interatrial septum is a rare congenital cardiac anomaly characterized by a distinct echolucent cavity between the atria formed by 2 separate interatrial septae. It may be a variant of other well-recognized cardiac anomalies such as persistent venous valve of the sinus venosus or cor triatriatum. Although uncommon, it may be associated with thromboembolic disease due to stagnant flow in the septal cavity. Awareness of this rare entity and its clinical significance along with a thorough echocardiographic examination to rule out similarly presenting or coexisting conditions are the key to an accurate diagnosis and appropriate management.

Surgical Echocardiography of the Mitral Valve: Focus on 3D

The mitral valve remains a complex structure where multiple forms of pathology can be seen. Mitral regurgitation continues to be one of the most common valvular diseases in the industrialized world. While intraoperative 2-dimensional transesophageal echocardiography has been commonplace for some time, 3-dimensional technology has emerged and has shown great benefit for diagnosis and guidance during mitral valve surgery. In the hands of a trained sonographer, high-quality real-time images can easily be obtained and correlate well with gross anatomical findings. The use of multiple angled views and color Doppler within 3-dimensional transesophageal echocardiography has become a valuable asset in the understanding and interpretation of the mitral valve for surgical interventions.

In response to Vanneman et al. on ‘Studies on the effectiveness of flipped classrooms’

According to our definition of FC, learners gain foundational knowledge prior to class when, where and how it is convenient, efficient and effective for them. Learners then apply that knowledge in classrooms through an active learning format. Thus, we believe that the learning techniques that were criticised as being confounders by Vanneman et al. are actually vital components of FC and are part of what presumably contributes to its theoretical benefits. We agree that researchers should do their best to track and equalise total time spent with the material between the FC and traditional lecture (TL) groups. However, to rigidly control learners’ preferred study strategies and time may amount to a disservice to learning as well as proving contrary to the purpose of FC, especially when referring to strategies used during self-directed preparation because time spent on homework or other self-directed activities to reinforce learning in TL is simply not something we control. We believe that the ideal study strategy would be to match the TL time with the combined time of the FC in-class session and the length of the pre-class video as Martinelli et al. did in their study.