Canadian Journal of Anesthesia, Vol 19, 239-250, Copyright © 1972 by Canadian Anesthesiologists' Society

Prediction of Adrenal Hypofunction in Anaesthesia

¹ Department of Anaesthesia, Hirosaki University school of Medicine, Hirosaki, Aomori-Ken, Japan

The present study was undertaken to investigate a possibility of predicting adrenal hypofunction and its prevention. Preoperative rapid synthetic ACTH test for measuring adrenal function was done for 30 control subjects not treated with steroid and 14 steroid-treated patients. The correlation between arterial hypotension during anaesthesia or operation and adrenocortical hypofunction in 39 patients previously treated with steroid was also studied. None of these patients received steroids on the day before operation or on the day of surgery. A group of ten patients who had no history of receiving steroid therapy and who underwent operations served as a control. Both groups of patients received the same premedication and halothane-N₂O anaesthesia.

The mean free cortisol level in the plasma after 30 minutes of halothane-N₂O anaesthesia alone (12.5 ± 1.0 µg per 100 ml) in the steroid treated patients slightly but significantly increased from the preinduction value (11.6 ± 1.0 µg per 100 ml), while in the control group it increased markedly from 10.8 ± 1.4 to 17.5 ± 1.4 µg per 100 ml. Plasma levels of cortisol one hour after the start of operation were significantly elevated (16.0 ± 1.3 µg) in the steroid treated patients, but in the control patients they rose more markedly to 26.3 ± 1.8 µg.

Arterial hypotension (systolic blood pressure less than 90 mm Hg) occurred in twelve steroid treated patients during anaesthesia alone or during operation. However, it was not necessary that the timing of hypotension corresponded with the lowest plasma cortisol level. None of the hypotensive patients developed shock, and they recovered without steroid administration except in one case. These data would suggest that low plasma free cortisol levels in the peripheral venous blood during anaesthesia or surgery are not necessary to development of arterial hypotension in the steroid treated patients and vice versa. According to our criteria by ACTH test, seven out of fourteen steroid-treated patients were judged as hypofunctional and hypotension was observed in three patients. In order to prevent a possible so-called adrenocortical insufficiency during operation in patients previously treated with steroid, the author suggests that the following patients should receive hormone preoperatively and during operation; (a) patients who showed subnormal response to ACTH test (b) patients currently under steroid treatment for more than one week (c) patients who have had continuous treatment for more than one month in the six months prior to operation or who have received more than 1 gm of cortisol or equivalent other steroids.