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Factors associated with perioperative complications during carotid endarterectomy. Anesth Analg 1982;61:631-7.Records from 166 cases of unilateral carotid endarterectomy were reviewed to investigate the association of certain preoperative and intraoperative factors with perioperative complications including hypertension and hypotension, neurologic deficit, myocardial infarction, and mortality. No myocardial infarctions occurred and mortality was zero.Complications associated with some of the study factors included postoperative hypertension and neurologic deficit. Postoperative hypertension occurred more frequently ( a ) in patients with poor preoperative blood pressure (BP) control (BP 2 170/95 torr) than in those with adequate control (BP < 170/95 torr) or normotension (52%. 35%, and 17%, respectively, p < 0.01 and, ( b ) when additional peripheral vascular disease was present (43% vs 25%. p < 0.05). The incidence of neurologic deficit was higher when hypertension developed after surgery (20%) than when patients remained normotensive (6%) or developed hypotension (O%, p < 0.05). Patients whose hypertension was poorly controlled had a greater incidence of transient neurologic deficit (23.8%) than patients with controlled hypertension (2.5%) or patients with normotension (1.5%, p < 0.01 1; permanent neurologic deficit occurred more frequently in those with bilateral disease on angiography than in those with unilateral disease (8.8% vs 1.2%, p < 0.05).

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Halothane and other halogenated anesthetic agents are liquids which are highly soluble in rubber and plastic materials widely used as components of anesthesia machines. These agents must be administered using machines equipped with vaporizers. We report a patient with a past history of halothane hepatitis in whom recurrence was suspected despite the fact that halothane had been avoided purposely during the subsequent operation. Circumstances led us to believe that inapparent circuit contamination of vaporizer-equipped anesthesia machine with halothane may be responsible for the inadvertant rechallenge and recurrence of halothane hepatitis. Vaporizer-equipped machines were tested for inapparent contamination with halothane and enflurane using Perkin-Elmer mass spectrometer. Oxygen alone was passed through the anesthesia circuits, and gas in the efferent limbs of the machines was tested for halothane (in eight machines) and enflurane (in two machines) which were found in various concentrations in all machines so tested. Our findings suggest that inapparent contamination may be widely prevalent in vaporizer-equipped anesthesia machines. The validity of this conclusion was confirmed in five patients with previous diagnosis of halothane hepatitis who subsequently underwent operations under general anesthesia during which machines never equipped with vaporizers were successful in preventing recurrence of hepatitis. We conclude that patients with a prior history of halothane hepatitis are at risk of inapparent circuit contamination-induced recurrent hepatitis. Unless such contamination can be confidently excluded, vaporizer-equipped machines should not be used to administer general anesthesia in these susceptible patients.