Paul S. Ramphal

Cardiopulmonary bypass simulation at the Boot Camp

OBJECTIVE At Boot Camp, we evaluated a modular approach to skills mastery related to cardiopulmonary bypass and crisis scenarios. METHODS With 32 first-year cardiothoracic surgery residents divided into 4 groups, 4 consecutive hours were devoted to cardiopulmonary bypass skills by using a perfused nonbeating heart model, computer-controlled CPB simulator, and perfused beating heart simulator. Based on the cardiopulmonary bypass simulator, each resident was assessed by using a checklist rating score on cardiopulmonary bypass management and 1 crisis scenario. An overall cardiopulmonary bypass score was determined. Economy of time and thought was assessed (1 = unnecessary/disorganized to 5 = maximum economy). At the end of the session, residents completed a written examination. Residents rated the sessions on cannulation skills, cardiopulmonary bypass knowledge, and cardiopulmonary bypass emergency and crisis scenarios on a 5-point scale (5 = very helpful to 1 = not helpful). RESULTS Thirty residents completed cardiopulmonary bypass simulator exercises. For initiation and termination of cardiopulmonary bypass, most residents performed the tasks and sequence correctly. Some elements were not performed correctly. For instance, 3 residents did not verify the activated clotting time before cardiopulmonary bypass initiation. Four residents demonstrated inadequate communication with the perfusionist, including lack of assertiveness and unclear commands. In crisis scenarios management of massive air embolism (n = 8) was challenging and resulted in the most errors; poor venous drainage and high arterial line pressure scenarios were managed with fewer errors. For the protamine reaction scenario, all residents (n = 7) identified the problem, but in 3 cases heparin was not redosed before resuming cardiopulmonary bypass for right ventricular failure. The score for economy of time and thought was 3.83 ± 0.6 (range, 3-5). The score of the written examination was 90.0 ± 11.3 (range, 60-100), which did not correlate with the overall cardiopulmonary bypass score of 91.4 ± 7.1 (range, 80-100; r = 0.07). The session on acquiring aortic cannulation skills was rated 4.92, that for cardiopulmonary bypass knowledge was rated 4.96, and that for cardiopulmonary bypass crisis scenarios was rated 4.96. CONCLUSIONS This Boot Camp session introduced residents early in their training to aortic cannulation, principles and management of cardiopulmonary bypass, and crisis management. Based on a modular approach, technical skills and knowledge of cardiopulmonary bypass can be acquired and assessed by using simulations, but further work with more comprehensive educational modules and practice will accelerate the path to mastery of these critical skills.

Experience With the Cardiac Surgery Simulation Curriculum: Results of the Resident and Faculty Survey

BACKGROUND The Cardiac Surgery Simulation Curriculum was developed at 8 institutions from 2010 to 2013. A total of 27 residents were trained by 18 faculty members. A survey was conducted to gain insight into the initial experience. METHODS Residents and faculty were sent a 72- and 68-question survey, respectively. In addition to demographic information, participants reported their view of the overall impact of the curriculum. Focused investigation into each of the 6 modules was obtained. Participants evaluated the value of the specific simulators used. Institutional biases regarding implementation of the curriculum were evaluated. RESULTS Twenty (74%) residents and 14 (78%) faculty responded. The majority (70%) of residents completed this training in their first and second year of traditional-track programs. The modules were well regarded with no respondents having an unfavorable view. Both residents and faculty found low, moderate, and high fidelity simulators to be extremely useful, with particular emphasis on utility of high fidelity components. The vast majority of residents (85%) and faculty (100%) felt more comfortable in the resident skill set and performance in the operating room. Simulation of rare adverse events allowed for development of multidisciplinary teams to address them. At most institutions, the conduct of this curriculum took precedence over clinical obligations (64%). CONCLUSIONS The Cardiac Surgery Simulation Curriculum was implemented with robust adoption among the investigating centers. Both residents and faculty viewed the modules favorably. Using this curriculum, participants indicated an improvement in resident technical skills and were enthusiastic about training in adverse events and crisis management.

Design of an electromechanical pump system for training in beating heart cardiac surgery

Heart surgeons and trainees benefit greatly from continuous practice of bypass surgery and other cardiac operations. This is true of beating heart surgery where, unlike traditional methods, the heart is not arrested during the operation. At the Dept. of Surgery, University Hospital of the West Indies (UHWI) a system has been devised to simulate a beating human heart using intra-ventricular balloons, which are inserted inside a preserved in vitro porcine heart and made to pulsate using a pneumatic pump. The work is currently being developed in collaboration with the School of Engineering at the University of Technology, Jamaica (UTech) and the Dept. of Mathematics & Computer Science at the University of the West Indies (UWI), with the aim of producing a computer controlled device capable of simulating the range of intra-operative cardiac behaviours typically found in heart surgery. An electromechanical pumping system is described, based on a computer controllable linear actuator. A comparison of associated pulsatile pump choices is presented along with results of the design of a prototype diaphragm pump, which was tested with the porcine heart, demonstrating normal and abnormal beating, and ventricular fibrillation. A software architecture is also presented, showing how the heart may be controlled in a variety of beating modes over the course of a surgical training session.

Myxoma of right femoral vein origin presenting as a right atrial mass with syncope

and respiratory muscle weakness. No known drug(s) associated with rhabdomyolysis, itself rare,4 were administered, nor were any metabolic factors present that are capable of potentiating this event. When rhabdomyolysis has been reported in patients undergoing longterm therapy, no acute causative factor is apparent.3,4 Rosenberg and colleagues,5 however, have documented intraoperative rhabdomyolysis associated with pravastatin in cases in which the operation was thought to be the trigger. Although speculative, 7 years of uneventful simvastatin therapy in this case, together with the report by Rosenberg’s group, indicates to us that the timing of this complication and operation were not coincidental. R E F E R E N C E S 1. Walker JF. World wide experience with simvastatin/lovastatin. Eur Heart J 1992;13(suppl B);21-2. 2. Campeau L, Knatterud G, Hunninghake B, Domanski N. Optimising cholesterol lowering therapy: contribution of the post coronary artery bypass graft trial. Eur Heart J 1997;18:1683-5. 3. Garnett WR. Interactions with hydroxy methylglutaryl coenzyme A reductase inhibitors. Am J Health Syst Pharm 1995;52:163944. 4. Kogan AD, Orenstein S. Lovastatin induced acute rhabdomyolysis. Postgrad Med J 1996;66:294-6. 5. Rosenberg AD, Neuwirth MJ, Kagen LJ, Singh K, Fischer HD, Bernstein RL. Intraoperative rhabdomyolysis in a patient receiving Pravostatin, a hydroxy-III-methylglutaryl co-enzyme A (HMG coA) reductase inhibitor. Anaesth Analg 1995;81:1089-91. The Journal of Thoracic and Cardiovascular Surgery Volume 116, Number 4 Brief communications 655

Acute renal failure post coronary artery bypass grafting at the University Hospital of the West Indies

OBJECTIVES The purpose of the study was to determine the period prevalence of acute renal failure (ARF) after coronary bypass surgery (CABG) at the University Hospital of the West Indies and to identify risk factors. METHOD A retrospective analysis of patients who underwent CABG during the period 1994-2004 was done. Data collected included; age, gender, weight, the presence of hypertension (HTN), diabetes mellitus (DM), hypercholesterolaemia, previous myocardial infarction (MI), blood pressure on admission, urea and creatinine one year prior to surgery, on admission for surgery and post-surgery, duration of intra-operative hypotension, duration of cardiopulmonary bypass, perfusion pressure and the perioperative medications. RESULTS The case notes of 62 patients (68.9%) were obtained for analysis. There were 47 (75.8%) males and 15 females (24.2%)--a 3:1 ratio. The prevalence of HTN and DM in the study sample was 78% and 72% respectively, hypercholesterolaemia was 31% and a previous MI was 29%. There were no differences based on gender. Post CABG complications were: persistent postoperative hypotension (6.8%), congestive cardiac failure (CCF) (6.8%), arrhythmia (6.8%), sepsis (6.8%), lower respiratory tract infection (LRTI) and pleural effusion (5.1%), heart block (3.4%), pulmonary embolism (1.7%), cellulitis and haematoma formation were 1.7%. Three patients had increases in postoperative creatinine values > 89 micromol/L over the postoperative value resulting in a prevalence of ARF of 5%. One of the three patients died and none received dialysis. There were no statistical difference in pre-operative clinical and biochemical characteristics based on the presence or absence of ARE. The presence of diabetes and increased length of stay were significant predictors of increasing postoperative creatinine values adjusting for pre-operative creatinine values. In addition, the presence of diabetes mellitus and male gender were significant predictors of increasing postoperative urea values. CONCLUSION DM is a significant risk factor for the development of ARF post CABG.

Cardiac training simulator using pump with electronic pressure to trigger ventricular fibrillation

Cardiac surgery training in a realistic surgical environment is assisted by a simulator based on an electromechanical pneumatic pump with associated control and display software. We describe a feedback mechanism for controlling the beating mode of the simulator by means of a electronic pressure sensor incorporated into the pneumatic pump. The sensor was incorporated into an electronic data acquisition board and was used to trigger a ventricular fibrillation (cardiac arrest) mode in the pump control system when the heart attached to the pump is handled by the trainee surgeon, as is typically experienced in a real operation. The mode change also results in changes to simulated vital signs including ECG and pressure traces which are displayed on a monitor within the surgical training environment. Software is described which was designed to drive the pump at various beating rates, display the vital signs, and respond to pressure sensor measurements. The work described is the continuation of a collaboration between the University Hospital of the West Indies (UHWI), the School of Engineering at the University of Technology, Jamaica (UTech), and the Dept. of Mathematics & Computer Science at the University of the West Indies (UWI), which has the aim of producing a computer controlled device and training system capable of simulating the range of intraoperative cardiac behaviours typically found in heart surgery, in order to improve training of resident surgeons.

Coronary Artery Bypass Graft Surgery at the University Hospital of the West Indies, Jamaica: Analysis of Clinical Characteristics, Mortality and Length of Hospital Stay

Objectives: A detailed analysis of coronary artery bypass graft (CABG) surgical cases performed at the University Hospital of the West Indies (UHWI) has never been conducted. We present the demographic profile, clinical characteristics, and outcome of cases performed during the period March 2010 to March 2016. Methods: Data from consecutive CABG surgeries performed during the study period were collected prospectively, entered into a computerized database and then analyzed. Outcome measures were 30-day operative mortality, ICU length of stay (ICU LOS) and total postoperative length of stay (PostOp LOS). Results: Of the 190 patients comprising the study population, 68.9% were males, and mean age (SD) was 61.3 (±10.2) years. The most frequent co-morbidities and risk factors were hypertension (82.1%) and diabetes (55.3%), cigarette smoking (33.7%) and hyperlipidaemia (89%). Left ventricular ejection fraction (LVEF) was found to be grades 1(good), 2(moderate), and 3(poor) in 50%, 44.2%, and 5.8% of patients, respectively. The majority (83%) were diagnosed with triple vessel disease. The crude, unadjusted 30-day mortality rate was 8.4%. Using the Canadian Risk Index Model, the mortality rates were: low risk (0-3), 5.5%; medium risk (4-7), 14.3%; and high risk (>8), 100%. The median ICU LOS and median postoperative LOS were 3 days (IQR, 2-4), and 8 days (IQR, 6-11), respectively. Logistic regression analysis revealed that grade 2 LVEF and urgent/emergent operations were predictors of mortality, female gender predictive of prolonged ICU LOS, and advanced age and female gender of borderline significance for prolonged PostOp LOS. Conclusion: This analysis of outcome of CABG cases performed at the UHWI provides an indication of current performance and serves as a benchmark against which future studies may be compared to determine the efficacy of future quality improvement initiatives.