Etomidate and the osteocalcin response to gynaecological surgery

Circulating osteocalcin is a good marker of osteoblastic activity and decre ases significantly after stressful physiological states such as major surge ry. Glucocorticoids are known to inhibit osteoblastic activity and result i n a decline in circulating osteocalcin. We used etomidate to inhibit the co rtisol response to routine gynaecological surgery to determine if this woul d prevent the postoperative decline in osteocalcin. Twenty-four patients we re allocated randomly to receive either thiopental or etomidate for inducti on of anaesthesia; all other aspects of anaesthesia and perioperative manag ement were standardized. In the thiopental group, circulating cortisol incr eased significantly at 2 and 6 h after the start of surgery and plasma oste ocalcin concentrations decreased significantly to almost 50% of baseline va lues at 48 h. Etomidate abolished the cortisol response to surgery, and cir culating osteocalcin concentrations did not change after operation. There w as a significant difference in osteocalcin concentration between the groups at 48 h. We conclude that the cortisol response to surgery is associated w ith a postoperative decrease in circulating osteocalcin.