Publications

OBJECTIVE: This study was designed to test the hypothesis that simulator-based transesophageal echocardiographic training was a more effective method of training anesthesia residents with no prior experience in echocardiography as compared with conventional methods of training (books, articles, and web-based resources).

STUDY DESIGN: A prospective randomized study.

SETTING: An academic medical center (teaching hospital).

PARTICIPANTS: The participants consisted of first-year anesthesia residents.

INTERVENTION: The study design was composed of 2 groups: a control group (group 1, conventional group) and a study group (group 2, simulator group). The residents belonging to group 2 (simulator group) received a 90-minute simulator-based teaching session moderated by a faculty experienced in transesophageal echocardiography. Residents belonging to group 1 (conventional group) were asked to review the guidelines of the comprehensive intraoperative transesophageal echocardiographic examination published by the American Society of Echocardiography and the Society of Cardiovascular Anesthesiologists. They also were encouraged to use other learning resources (eg, textbooks, electronic media, and web-based resources) to understand the underlying concepts of echocardiography. Written pre- and post-test was administered to both groups.

MEASUREMENTS AND MAIN RESULTS: The groups were compared for the pretest scores by the nonparametric Mann-Whitney U test. Pre- and post-test scores were compared with a Wilcoxon paired test in the individual groups. The results showed a statistically significant difference between the scores of the 2 groups with better scores in the simulation group in the post-training test.

CONCLUSION: The simulator-based teaching model for transesophageal echocardiography is a better method of teaching the basic concepts of transesophageal echocardiography like anatomic correlation, structure identification, and image acquisition.

OBJECTIVE: This study was designed to test the hypothesis that simulator-based transesophageal echocardiographic training was a more effective method of training anesthesia residents with no prior experience in echocardiography as compared with conventional methods of training (books, articles, and web-based resources).

STUDY DESIGN: A prospective randomized study.

SETTING: An academic medical center (teaching hospital).

PARTICIPANTS: The participants consisted of first-year anesthesia residents.

INTERVENTION: The study design was composed of 2 groups: a control group (group 1, conventional group) and a study group (group 2, simulator group). The residents belonging to group 2 (simulator group) received a 90-minute simulator-based teaching session moderated by a faculty experienced in transesophageal echocardiography. Residents belonging to group 1 (conventional group) were asked to review the guidelines of the comprehensive intraoperative transesophageal echocardiographic examination published by the American Society of Echocardiography and the Society of Cardiovascular Anesthesiologists. They also were encouraged to use other learning resources (eg, textbooks, electronic media, and web-based resources) to understand the underlying concepts of echocardiography. Written pre- and post-test was administered to both groups.

MEASUREMENTS AND MAIN RESULTS: The groups were compared for the pretest scores by the nonparametric Mann-Whitney U test. Pre- and post-test scores were compared with a Wilcoxon paired test in the individual groups. The results showed a statistically significant difference between the scores of the 2 groups with better scores in the simulation group in the post-training test.

CONCLUSION: The simulator-based teaching model for transesophageal echocardiography is a better method of teaching the basic concepts of transesophageal echocardiography like anatomic correlation, structure identification, and image acquisition.

BACKGROUND: We used echocardiographically derived myocardial performance index (MPI) to assess changes in global right ventricular function with lung isolation. We hypothesized that changes in MPI with lung isolation may be related to the incidence of postoperative supraventricular tachycardia (SVT).

METHODS: Transesophageal echocardiographic examinations were performed after induction of general anesthesia in patients undergoing elective lung resections. Doppler tissue imaging was used to calculate MPI at baseline and 10 minutes after institution of one-lung ventilation (OLV). Arrhythmias occurring within the first 5 postoperative days were recorded.

RESULTS: Fifty-nine patients completed the study. Nineteen of 59 patients with a normal baseline MPI (<0.40) had a higher incidence of SVT as compared with patients with an abnormal baseline MPI (42% versus 10%; p = 0.012). The MPI worsened during OLV in 46 patients; a worsening of MPI with lung isolation that was normal at baseline was associated with higher incidence of SVT (57% versus 0%; p = 0.045) compared with a worsening of MPI in patients with an abnormal baseline MPI (13% versus 6%; p = 0.62). A normal baseline MPI value that worsened after OLV, left atrial dilation, and advanced age were identified as predictors of postoperative SVT.

CONCLUSIONS: Lung isolation is associated with acute changes in global right ventricular function. A normal baseline MPI that worsens after lung isolation is a better predictor of postoperative SVT as compared with baseline abnormal MPI that does not worsen after lung isolation. Myocardial performance index has a potential to be used as a right ventricular stress test to tolerate OLV before thoracic surgery.

BACKGROUND: We used echocardiographically derived myocardial performance index (MPI) to assess changes in global right ventricular function with lung isolation. We hypothesized that changes in MPI with lung isolation may be related to the incidence of postoperative supraventricular tachycardia (SVT).

METHODS: Transesophageal echocardiographic examinations were performed after induction of general anesthesia in patients undergoing elective lung resections. Doppler tissue imaging was used to calculate MPI at baseline and 10 minutes after institution of one-lung ventilation (OLV). Arrhythmias occurring within the first 5 postoperative days were recorded.

RESULTS: Fifty-nine patients completed the study. Nineteen of 59 patients with a normal baseline MPI (<0.40) had a higher incidence of SVT as compared with patients with an abnormal baseline MPI (42% versus 10%; p = 0.012). The MPI worsened during OLV in 46 patients; a worsening of MPI with lung isolation that was normal at baseline was associated with higher incidence of SVT (57% versus 0%; p = 0.045) compared with a worsening of MPI in patients with an abnormal baseline MPI (13% versus 6%; p = 0.62). A normal baseline MPI value that worsened after OLV, left atrial dilation, and advanced age were identified as predictors of postoperative SVT.

CONCLUSIONS: Lung isolation is associated with acute changes in global right ventricular function. A normal baseline MPI that worsens after lung isolation is a better predictor of postoperative SVT as compared with baseline abnormal MPI that does not worsen after lung isolation. Myocardial performance index has a potential to be used as a right ventricular stress test to tolerate OLV before thoracic surgery.

OBJECTIVE: To assess the association of perioperative cardiac dysfunction during elective vascular surgery with postoperative outcome.

BACKGROUND: Patients with normal systolic function can have isolated diastolic dysfunction. Routine preoperative evaluation of left ventricular (LV) function does not include an assessment of diastolic function for risk stratification. We hypothesized that perioperative assessment of both diastolic and systolic function with transesophageal echo (TEE) may improve our ability to predict postoperative outcome.

METHODS: Perioperative TEE examinations were carried out on patients undergoing elective vascular surgery under general anesthesia. Abnormal systolic function was defined as LV ejection fraction (LVEF) <40%. Left ventricular diastolic function was assessed using transmitral flow propagation velocity (Vp); Vp <45 cm/sec was considered abnormal. We determined the association between LV function and the primary outcome of postoperative adverse outcome, defined as one or more adverse events: myocardial infarction (MI), congestive heart failure (CHF), significant arrhythmia, prolonged intubation, renal failure, and death.

RESULTS: Three hundred thirteen patients undergoing vascular surgery were studied. We found that 8% (n = 24) of patients had isolated systolic dysfunction, 43% (n = 134) had isolated diastolic dysfunction, and 24% (n = 75) both systolic and diastolic dysfunction. The most common postoperative adverse outcome was CHF 20% (n = 62). By multivariate logistic regression, we found that patient age, Vp, type of surgery, female gender, and renal failure were predictive of postoperative adverse outcome.

CONCLUSION: The presence of perioperative diastolic dysfunction as assessed with Vp is an independent predictor of postoperative CHF and prolonged length of stay after major vascular surgery. Patient age, gender, type of surgery, and renal failure were also predictors of outcome. Perioperative systolic function was not a predictor of postoperative outcome in our patients.

BACKGROUND: A growing body of evidence suggests that hyperglycemia is an independent predictor of increased cardiovascular risk. Aggressive glycemic control in the intensive care decreases mortality. The benefit of glycemic control in noncardiac surgery is unknown.

METHODS: In a single-center, prospective, unblinded, active-control study, 236 patients were randomly assigned to continuous insulin infusion (target glucose 100-150 mg/dl) or to a standard intermittent insulin bolus (treat glucose > 150 mg/dl) in patients undergoing peripheral vascular bypass, abdominal aortic aneurysm repair, or below- or above-knee amputation. The treatments began at the start of surgery and continued for 48 h. The primary endpoint was a composite of all-cause death, myocardial infarction, and acute congestive heart failure. The secondary endpoints were blood glucose concentrations, rates of hypoglycemia (< 60 mg/dl) and hyperglycemia (> 150 mg/dl), graft failure or reintervention, wound infection, acute renal insufficiency, and duration of stay.

RESULTS: The groups were well balanced for baseline characteristics, except for older age in the intervention group. There was a significant reduction in primary endpoint (3.5%) in the intervention group compared with the control group (12.3%) (relative risk, 0.29; 95% confidence interval, 0.10-0.83; P = 0.013). The secondary endpoints were similar. Hypoglycemia occurred in 8.8% of the intervention group compared with 4.1% of the control group (P = 0.14). Multivariate analysis demonstrated that continuous insulin infusion was a negative independent predictor (odds ratio, 0.28; 95% confidence interval, 0.09-0.87; P = 0.027), whereas previous coronary artery disease was a positive predictor of adverse events.

CONCLUSION: Continuous insulin infusion reduces perioperative myocardial infarction after vascular surgery.