Comparison of the hemodynamic effects of nitroprusside and remifentanil for controlled hypotension during endoscopic...

Controlled hypotension (CH) is a well-established technique to decrease blood loss and improve surgical visibility. Although nitroprusside and remifentanil have been safely and effectively used for this purpose, the hemodynamic changes that occur during CH are unclear. This study compared the effects of nitroprusside and remifentanil on hemodynamics using a noninvasive cardiac output monitor (Cheetah NICOM(®); Cheetah Medical Inc., Maidenhead, Berkshire, UK) for endoscopic sinus surgery (ESS).

Twenty-eight adult patients scheduled for ESS were randomly assigned to the nitroprusside group (n = 14) or remifentanil group (n = 14). After anesthesia induction, hypotension was induced with continuous infusion of nitroprusside or remifentanil at a target mean arterial blood pressure (MAP) of 60-70 mmHg. Cardiac index (CI), stroke volume index (SVI) and total peripheral resistance index (TPRI) were measured at 10-min intervals.

The heart rate was higher and SVI was lower in the nitroprusside group than in the remifentanil group during CH. There were no significant differences in MAP, CI or TPRI between the two groups. Both nitroprusside and remifentanil reduced MAP and TPRI during CH compared with baseline values. However, there was no significant change in CI.

Both nitroprusside and remifentanil were effective to induce CH and maintain CI during CH.