Influence of Flunitrazepam , Morphine , Nitrous Oxide Balanced Anestheeia on Adrenocortical Function / 대한마취과학회지

ABSTRACT

Corticosteroids have endowed the organism with the capacity to resist many types of noxious stimuli, and enviromental changes. Although many anesthetic agents and surgical stress have been shown to have some influence on adrenocortical function in man, there is no report on the effect of flunitrazepam-morphine-nitrous oxide anesthesia on endocrine activity. The present investigation was undertaken to study to what extent flunitrazepam-morphine-nitrousoxide anesthesia nfluences adrenocortical function by judging its effect on plasma cortisol levels in peripheral venous blood in man. Fifteen patients, ranging in age from 17 to 48 years (average 33 years) and in weight from 46kg to 73kg(average 58kg) who underwent various surgical operations, were free from endocrine, neurological, hepatic, renal and cardiopulmonary disease. Each patient was premedicated with atropine sulfate(0.01mg/kg) and Valium(0.15mg/kg) i.m. one hour before the induction of anesthesia. Anesthesia was induced at 9:00 a.m. with flunitreazepam(0.05+/-0.01mg/kg) and morphine(0.29+/-0.04mg/kg) was given by intreavenous injection. Pancuronium bromide(0.09+/-0.013 mg/kg) was given intreavenously for endotracheal intubation. General anesthesia was maintained with nitrous oxide 2L/min. and oxygen 1L/min. controlled ventilaration was carried on throughout the procedure. A moderate depth of anesthesia was maintained by clinical judgment based on signs including blood pressure and pulse rate. Blood samples were obtainesd at the following times: 1) the control group at 9:00 a.m. just prior to induction. 2) 30 min after anesthesia only. 3) 30 min. after the start of operation. Venous blood(5ml) was drawn into an aseptic syringe previously rinsed with heparin. The plasma was separated within 30 min. in a refrigerated centrifuge, then frozen at -40 degrees C. for storage. the cortisol levels in plasma were determined by a Gamma coat I 125 cortisol radiommunoassay kit. The plama cortisl level at 9:00 a.m. just prior to induction in the control group was 12.64+/-3.77 ug/ml. It decreased slightly (about 20%) but no significantly(p>0.01) to 10.11+/-2.47 ug/100ml at 30 min. after the anesthesia alone. At 30 min. after the start of operation it was elevated slightly (about 24%) but not significantly(p>0.1) to 15.42+/-6.88 ug/100ml. This finding indicated that flunitrazepam-nitrous oxide anesthesia has a depressing effect on adrenal cortical function, but did not block the influence on adrenal cortical function of surgical stress.