Hypotensive anesthesia for total hip arthroplasty: a study of blood loss and organ function (brain, heart, liver, and kidney).

The authors attempted to determine whether hypotensive anesthesia or the method of inducing hypotension has any effect on postoperative brain, liver, or kidney function and myocardial status following total hip arthroplasty. Thirty patients were anesthestized with halothane-nitrous oxide for total hip arthroplasty and randomly assigned to one of three groups. In two groups mean arterial blood pressure was decreased to 50 torr by high inspired concentrations of halothane (n = 90) or sodium nitroprusside (n = 12). In the third group (n = 9) mean blood pressure was maintained within 20% of control. Intraoperative blood losses decreased from 1,183 +/- 172 ml in the normotensive group to 406 +/- 102 ml and 326 +/- 41 ml in the halothane and nitroprusside hypotensive groups, respectively. Neither method of inducing hypotension nor hypertensive technique affected the results of postoperative tests of cerebral, hepatic, or renal function and myocardial status. These tests were performed before anesthesia and operation and at intervals in the postoperative course. In this small group of patients, deliberate hypotension for total hip arthroplasty added no morbidity and significantly shortened operating time, decreased blood loss, and decreased the number of blood transfusions needed.