Effects of anesthetic technique on myocardial wall motion abnormalities during abdominal aortic surgery.

OBJECTIVE: To assess the impact of regional supplemented general anesthesia (RSGEN) on regional myocardial function during abdominal aortic surgery (AAS). DESIGN: Prospective randomized study. SETTING: Single academic medical center. PARTICIPANTS: Seventy-three patients scheduled for infrarenal aortic aneursymectomy. INTERVENTIONS: Patients received standardized intraoperative anesthetic management consisting of either general anesthesia (GA; n = 37) or general anesthesia supplemented by epidural anesthesia (RSGEN; n = 36). MEASUREMENTS AND MAIN RESULTS: Hemodynamic measurements and transesophageal echocardiograms (TEE) were obtained at eight intraoperative times. The electrocardiogram (ECG) was continuously recorded using Holter monitoring. Of the 56 patients with interpretable TEE recordings, 8 of 30 (27%) GA patients and 7 of 26 (27%) RSGEN patients developed new segmental wall motion abnormalities (SWMAs). There was no treatment effect on either the incidence (p = 0.23) or the intensity (p = 0.34) of SWMAs. Cross-clamping of the aorta was associated with the onset of new SWMAs (odds ratio, 8.2; 95% CI, 1.1 to 64; p = 0.04). Among the 63 patients with interpretable Holter recordings, 9 of 34 (26%) GA patients and 9 of 29 (31%) RSGEN patients exhibited intraoperative ischemia. There was no treatment effect on the incidence (p = 0.22) or intensity (p = 0.67) of ECG ischemia. CONCLUSION: Despite providing modest hemodynamic depression, RSGEN did not reduce the incidence or intensity of either regional myocardial dysfunction or ECG ischemia. New SWMAs were temporally associated with cross-clamping of the aorta and tended to resolve with unclamping.

Use of the laryngeal mask airway in managing a patient with a large anterior mediastinal mass: a case report.

This is a case presentation of a patient with a large anterior mediastinal mass in whom the airway was maintained with a laryngeal mask airway. The patient was otherwise managed in the "classic" fashion with spontaneous respiration via a light general anesthetic. In reviewing many of the potential pitfalls of anesthesia in this class of patients, the laryngeal mask airway was found to be both a valuable and viable option for airway management.

Prophylactic nitroglycerin infusion during noncardiac surgery does not reduce perioperative ischemia.

We evaluated the impact of prophylactic nitroglycerin on the incidence of perioperative myocardial ischemia in patients with known or suspected coronary artery disease who undergo noncardiac surgery. Our goals were to better define the role of nitroglycerin in the management of high-risk patients and to explore the mechanisms of perioperative myocardial ischemia. Patients were assigned randomly to either a control group (n = 23) or to receive 0.9 micrograms.kg-1.min-1 of intravenous nitroglycerin (n = 22). The diagnosis of myocardial ischemia was based on a review of Holter electrocardiogram (ECG) recordings. There was no difference in the incidence of ischemia between groups. Seven control patients (30%) and seven nitroglycerin patients (32%) exhibited ECG evidence of ischemia. The preponderance of myocardial ischemia occurred during emergence from anesthesia (of the 14 patients exhibiting ischemia, 12 did so at emergence). There was an acute increase in heart rate at the onset of ischemia in all patients exhibiting ischemia with 14 of 18 episodes associated with an increase of 20% or greater. The heart rate associated with the onset of ischemia was greater in the nitroglycerin-treated patients than in the control group. We also found that the occurrence of myocardial ischemia on a preoperative Holter recording was strongly predictive of the subsequent occurrence of perioperative ischemia. In conclusion, the addition of nitroglycerin to standard anesthetic management of these high-risk patients does not measurably reduce perioperative ischemia.