Anesthesiology
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Randomized Controlled Trial Clinical Trial
Addition of nitrous oxide to fentanyl anesthesia does not induce myocardial ischemia in patients with ischemic heart disease.
Although nitrous oxide is commonly administered to patients with ischemic heart disease, recent reports suggest that it may induce myocardial ischemia in these patients. The authors compared the effects of nitrous oxide on segmental left ventricular (LV) function and the ST segment of the electrocardiogram with the effects of an equal concentration of nitrogen (crossover design) before the start of surgery in 18 patients who required coronary-artery bypass grafting. The patients studied did not have valvular or LV dysfunction. ⋯ Surgery did not begin until the study was concluded. No patient experienced an ST segment change greater than 1 mm during the study, and none developed a new segmental wall motion abnormality during inhalation of either nitrous oxide or nitrogen. The authors conclude that nitrous oxide does not induce myocardial ischemia when used as an adjunct to fentanyl anesthesia in patients who have severe coronary-artery disease accompanied by well-preserved valvular and LV function.