전신마취와 척추마취 하에 하지 수술시 구혈기에 의한 혈역학적 변화

Abstract

A tourniquet is commonly used to achieve a bloodless field in surgery of the extremities. However, tourniquet use occasionally has been associated with intranperative hypertension and with circulatory collapse after deflation. The purpose of this study is to define the hemodynamic changes in this setting using thoracic electrical bioimpedance (TEB) device. Twenty patients of ASA class I, scheduled for lower extremities surgery using a thigh tourniquet, were randomly divided into two groups. Group I underwent general anesthesia (including enflurane) and group Ⅱ underwent spinal anesthesia (0.5% bupivacaine 12.5 mg). The changes of blood pressure (BP), heart rate (HR), stroke index (SI), cardiac index (CI), systemic vascular resistance index (SVRI), and end-diastolic index(EDI) were measured (1) before induction, (2) just before inflation of tourniquet, (3) at the time of the maximal change of CI within 10 minutes after inflation of it, (4) just before deflation of tourniquet, and (5) at the time of the maximal change of CI within 10 minutes after deflation of it. During a tourniquet inflation, SI, CI and SVRI were markedly changed in group I , but not effectively changed in group H. During a tourniquet deflation, CI and SVRI were changed significantly in group I and only SVRI was decreased effectively in group Ⅱ (p<0.05). However, there were no significant changes in BP, HR, and EDI in both groups during a tourniquet inflation and deflation. In cases of the use of a thigh tourniquet for lower extremities surgery, the hemodynamic fluctuations of CI and SVRI are obviously less changed in the spinal than in the general anesthesia during the inflation and deflation of a tourniquet and prominent during 5-10 minutes just after inflation and deflation of a tourniquet. Accordingly, it is suggested that spinal anesthesia is preferred to general anesthesia for the use of a thigh tourniquet in patients scheduled for lower extremities surgery and close observation is required during 5-10 minutes just after inflation and deflation of a tourniquet.