Open AccessNo Finding of Increased Myocardial Ischemia During or After Carotid Endarterectomy Under Anesthesia With Nitrous Oxide
Author(s) -
Steven V. Kozmary,
George H. Lampe,
David J. Benefiel,
Michael K. Cahalan,
Linda Z. Wauk,
Patricia Whitendale,
Nelson B. Schiller,
Edmond I. Eger
Publication year - 1990
Publication title -
anesthesia and analgesia/anesthesia and analgesia
Language(s) - English
Resource type - Journals
eISSN - 1526-7598
pISSN - 0003-2999
DOI - 10.1213/00000539-199012000-00003
Subject(s) - medicine , ischemia , isoflurane , myocardial infarction , carotid endarterectomy , anesthesia , anesthetic , cardiology , creatine kinase , perioperative , chest pain , infarction , carotid arteries
Nitrous oxide (N2O) has been implicated as a cause of myocardial ischemia. We investigated whether substitution of N2O for a portion of the anesthesia supplied by isoflurane increased myocardial ischemia in patients at risk for such ischemia. Seventy patients having carotid endarterectomies (63 patients) or other carotid surgery (seven patients) were prospectively, randomly assigned to an anesthetic regimen that included or excluded N2O. All other aspects of anesthetic management were similar, except for greater concentrations of oxygen and isoflurane in patients not given N2O. Perioperative monitoring for myocardial ischemia and infarction included 12- or 5-lead electrocardiography, transesophageal echocardiography, and creatine kinase isoenzyme levels. By transesophageal echocardiographic or electrocardiographic criteria, 44% of patients given oxygen but only 21% of those given N2O had myocardial ischemia intraoperatively (P = 0.065). Similarly, myocardial infarction, identified by changes in creatine kinase isoenzymes, occurred in only one patient given N2O but in three given oxygen (not significantly different). Thus we found no trend indicating a greater incidence of myocardial ischemia or infarction associated with the use of N2O.