Jeremy S. Dority

Anesthetic Implications of Obesity in the Surgical Patient

The obese patient presents many challenges to both anesthesiologist and surgeon. A good understanding of the pathophysiologic effects of obesity and its anesthetic implications in the surgical setting is critical. The anesthesiologist must recognize increased risks and comorbidities inherent to the obese patient and manage accordingly, optimizing multisystem function in the perioperative period that leads to successful outcomes. Addressed from an organ systems approach, the purpose of this review is to provide surgical specialists with an overview of the anesthetic considerations of obesity. Minimally invasive surgery for the obese patient affords improved analgesia, postoperative pulmonary function, and shorter recovery times at the expense of a more challenging intraoperative anesthetic course. The physiologic effects of laparoscopy are discussed in detail. Although laparoscopys physiologic effects on various organ systems are well recognized, techniques provide means for compensation and reversing such effects, thereby preserving good patient outcomes.

Subarachnoid Hemorrhage: An Update

Subarachnoid hemorrhage (SAH) is a debilitating, although uncommon, type of stroke with high morbidity, mortality, and economic impact. Modern 30-day mortality is as high as 40%, and about 50% of survivors have permanent disability. Care at high-volume centers with dedicated neurointensive care units is recommended. Euvolemia, not hypervolemia, should be targeted, and the aneurysm should be secured early. Neither statin therapy nor magnesium infusions should be initiated for delayed cerebral ischemia. Cerebral vasospasm is just one component of delayed cerebral edema. Hyponatremia is common in subarachnoid hemorrhage and is associated with longer length of stay, but not increased mortality.

Surgical Resident Training Using Real-Time Simulation of Cardiopulmonary Bypass Physiology with Echocardiography

BACKGROUND With increasing complexity of medical care and continuing limitations on medical education, the use of simulation is becoming ever more important. Several simulators have been developed to teach procedural-based surgical tasks. The care of the cardiac surgical patient requires an in-depth understanding of physiology, particularly as pertains to cardiopulmonary bypass. We describe the use of the Human Patient Simulator (HPS) to teach perioperative fundamentals to surgical residents. METHODS General surgery residents from the University of Kentucky participated in an interactive simulation pilot program. The METI (Medical Education Technology, Inc, Sarasota, Florida) HPS was used with custom programming to demonstrate simulated intraoperative and postoperative physiology related to cardiopulmonary bypass. Didactics, in addition to intraoperative echocardiographic images, were provided. Fund of knowledge was assessed by a computerized pre- and posttest that was administered to the trainees, and self-assessment data were collected using a Likert scale. RESULTS Nineteen general surgery residents participated. An overall improvement in performance on the test was demonstrated from 63% correct to 85% correct. In general, residents found the simulation useful, appreciated the opportunity to treat crisis situations without risk of harm to a patient, and felt they could apply the knowledge gained from this program in their future practice. CONCLUSIONS Simulation serves as a useful adjunct to medical education. We have demonstrated the use of the HPS to provide a real-time simulation of the physiology of cardiopulmonary bypass and postoperative care. We plan to use this system as part of our standard curriculum of training rotating residents and junior fellows and anticipate this system could be used as part of future cardiothoracic simulations.

Neurophysiological monitoring simulation using flash animation for anesthesia resident training.

Introduction: Surgery of the spine is associated with the possible complication of permanent nerve injury. Neurophysiological monitoring is widely used during spine surgery to decrease the incidence and severity of neurologic injury. A profound understanding of physiological and pharmacological factors influencing evoked potentials is expected from the anesthesia provider. Methods: Because demonstration and teaching of all somatosensory evoked potential (SSEP) changes is difficult in the clinical environment, we developed human patient simulator scenarios to facilitate the anesthesia resident training in neurophysiological monitoring. A SSEP simulation for resident training was created using flash animation in a patient simulation program and is the focus of this report. Feedback from participants (anesthesia residents) was obtained by a postscenario survey. Results: This report provides a detailed description of the scenario and computer program. The survey findings indicated that the simulation session is an effective teaching method of SSEP monitoring. Conclusion: Flash animation integration into a patient simulation program for SSEP monitoring appears to be an effective method for anesthesia resident education in neurophysiological monitoring.

The Impact of Exposure to Liver Transplantation Anesthesia on the Ability to Treat Intraoperative Hyperkalemia: A Simulation Experience

The objective of this study was to assess whether resident exposure to liver transplantation anesthesia results in improved patient care during a simulated critical care scenario. Our hypothesis was that anesthesia residents exposed to liver transplantation anesthesia care would be able to identify and treat a simulated hyperkalemic crisis after reperfusion more appropriately than residents who have not been involved in liver transplantation anesthesia care. Participation in liver transplantation anesthesia is not a mandatory component of the curriculum of anesthesiology training programs in the United States. It is unclear whether exposure to liver transplantation anesthesia is beneficial for skill set development. A high-fidelity human patient simulation scenario was developed. Times for administration of epinephrine, calcium chloride, and secondary hyperkalemia treatment were recorded. A total of 25 residents with similar training levels participated: 13 residents had previous liver transplantation experience (OLT), whereas 12 residents had not been previously exposed to liver transplantations (non-OLT). The OLT group performed better in recognizing and treating the hyperkalemic crisis than the non-OLT group. Pharmacologic therapy for hyperkalemia was given earlier (OLT 53.3 ± 27.0 seconds versus non-OLT 148 ± 104.1 seconds; P < 0.01) and hemodynamics restored quicker (OLT 87.9 ± 24.9 seconds versus non-OLT 219.9 ± 87.1 seconds; P < 0.01). Simulation-based assessment of clinical skills is a useful tool for evaluating anesthesia resident performance during an intraoperative crisis situation related to liver transplantations. Previous liver transplantation experience improves the anesthesia residents ability to recognize and treat hyperkalemic cardiac arrest.

Cognitive aid use improves transition of care by graduating medical students during a simulated crisis

Background Residents are expected to have transition of care (ToC) skills upon entering graduate medical education. It is unclear whether experience and training during medical school is adequate. Objective The aim of the project was to assess: 1) graduating medical students’ ability to perform ToC in a crisis situation, and 2) whether using a cognitive aid improves the ToC quality. Methods The authors developed simulation scenarios for rapid response teams and a cognitive aid to assist in the ToC during crisis situations. Graduating medical students were enrolled and randomly divided into teams of three students, randomly assigned into one of two groups: teams using a cognitive aid for ToC (CA), or not using a cognitive aid (nCA). In the scenario, teams respond to a deteriorating patient and then transfer care to the next provider after stabilization. Three faculty reviewed the recording to assess completeness of the ToC and the overall quality. A completeness score was expressed as a fraction of the maximum score. Statistical analysis was performed using a t-test and Mann-Whitney U test. Results A total of 112 senior medical students participated: CA n=19, nCA n=17. The completeness score of the ToC and overall quality improved when using the cognitive aid (completeness score: CA 0.80±0.06 vs. nCA 0.52±0.07, p<0.01; ToC quality: CA 3.16±0.65 vs. nCA 1.92±0.56, p<0.01). Participants’ rating of knowledge and comfort with the ToC process increased after the simulation. Conclusion The completeness of information transfer during the ToC process by graduating medical students improved by using a cognitive aid in a simulated patient crisis.

Neurocritical care in aneurysmal subarachnoid haemorrhage: The evidence - based approach

is the strongest predictor of rupture, re‐bleeding of the aneurysm may be in part attributable to uncontrolled hypertension. A titratable agent, e.g., nicardipine, should be used to prevent extreme hypertension and specific blood pressure goals should be individualised based on a patient’s age, cardiac history, baseline blood pressure and aneurysm size. Hypotension must also be avoided as it may compromise cerebral perfusion pressure and increase both the risk and size of stroke. INTERACT‐2 demonstrated the safety of targeting systolic blood pressure <140 mmHg when compared to a target of <180 mmHg. Similarly, intracerebral haemorrhage ADAPT compared a target of <150–<180 mmHg and did not find a reduction in blood flow on computed tomography (CT) perfusion. Our practice is to target systolic blood pressure <140 mmHg using nicardipine as the first‐line agent.[2] Antihypertensive Treatment of Acute Cerebral Haemorrhage‐II, a multicentre, randomised, controlled, phase III trial has enrolled 1000 subjects and will evaluate intensive systolic blood pressure reduction to 140 mmHg using nicardipine compared to 180 mmHg in the control arm.