The use of tourniquet is associated with severe hemodynamic changes, particularly in elderly patients. This study examined the effects of continuously infused remifentanil or nicardipine with esmolol on the attenuation of the hemodynamic changes with enflurane inhalation during total knee arthroplasty in elderly patients.

Thirty elderly female patients undergoing total knee arthroplasty were enrolled into this randomized, prospective study. Remifentanil (group R) or nicardipine with esmolol (group EN) was infused using a titration method to maintain a mean arterial pressure (MAP) of 90 mmHg to 70 mmHg during tourniquet inflation. In addition, the inhalation of enflurane was adjusted to guarantee a hypnotic state based on entropy. The hemodynamic variables, inhaled concentration of enflurane, recovery time, and postoperative pain characteristics were measured and compared.

Following tourniquet inflation, the MAP was increased and maintained in the target since 20 min after that in both group. Following tourniquet deflation the MAP was decreased significantly in both groups and more patients in group R required a vasopressor. Group R inhaled a lower enflurane concentration and showed more rapid recovery than group EN. There were no significant differences in the level of postoperative pain between the two groups.

These results suggest that remifentanil is more likely to be associated with hypotension after tourniquet deflation and require more attention than nicardipine with esmolol.