A Clinical Evaluation of Hypotensive Anesthesia for Posterior Stabilization and Fusion of Sdpine

Kim, Won Hong; Kim, Won Tai; Kim, Young Il

Abstract

Deliberate hypotension reduces bleeding in a wound, there by providing the surgeon with both better visibility and technical freedom for a more definitive dissection and minimizes the need for blood replacement, thereby reducing the risks of transfusion reactions, hepatitis, and acquired immune deficiency syndrome (AlDS). anesthesia With major development in surgery for spine problems in this century there are many reports and studies about the pathophysiology of spine, cord hemodynamics and functional monitoring about spinal cord activity during induced hypotension. Although by the comparative studies of vasodilator deliberate hypotension with nitroprusside was found to induce a reliable and rapid drop in blood pressure, we have found some different responses to the chosen vasodilators between the older, less active groups and the healthy, robust, and physically active groups. In this study we evaluated the hypotensive anesthesia for 42 cases of spinal surgery-posterior stabilization, spinal fusion, laminectomy, osteotomies, and discectomy-performed at Kwangju Christian Hoispital from May 1987 to May 1988. The result of our study was as follows: 1) Halothane and enflurane were used as primary anesthetics in 31 and ll cases respectively. Nitroprusside, hydralazine and both of this two vasodilatora were supplementarily used for inducing hypotensin in 14, 16 and 5 cases, respectively. 2) Although in many paient particularly in the older and less active groups, the combination of halogenated anesthetics and hydralazine are sufficient to produce appropriate operating conditions, in healthy, robust and physicaly active groups nitroprusside or even the combination of two vasodilators are required. 3) The mean arterial pressure of the lowest blood pressure in the induced hypotension was 60.5+/-11.6 mmHg. 4)The mean blood loss and blood replacement was 1242.2+/-769 ml and 925.4+/-854 ml respectively. 5) In the intraoperative period gas analysis arterial CO2 tension was 34.2+/-6.6mmHg and other values was within normal limit. 6) There was no significant perioperative and postoperative complication due to induced hypotension itself. In conclusion, the technique of using induced hypotension with inhalation anesthetics supplemented by nitroprusside, hydralazine, or both is safe and useful one to use in performing surgery for spinal problems.