THE EFFECT OF ISOFLURANE OR SPINAL-ANESTHESIA ON INDOCYANINE GREEN DISAPPEARANCE RATE IN THE ELDERLY

This study was designed to measure the disappearance rate of indocyani ne green (ICG) as an indicator of hepatic blood flow in elderly patien ts undergoing internal fixation of fractured neck of femur. All patien ts were aged 60-90 yr and were randomized to receive either spinal (n = 10) or isoflurane (n = 10) anesthesia. In both groups systolic arter ial blood pressure was maintained within 15% of resting levels by admi nistration of fluids intravenously without vasoactive drugs. Patients were excluded if they required vasopressors to maintain arterial blood pressure. ICG disappearance rate was calculated using a single bolus technique before induction of anesthesia, and at 30, 60, and 120 min a fter induction of anesthesia. Sixteen patients completed the study The re were no statistically significant changes in ICG disappearance rate in either group at any time during the study, indicating that hepatic blood flow is not significantly altered by either spinal or isofluran e anesthesia provided that arterial blood pressure is maintained.