Abstract

The cause of postanesthesia shaking (PS) is unknown. PS develops spontaneously and unpredictably in up to 67% of patients emerging from general anesthesia, and it continues for minutes to hours when not treated with medications or radiant heat lamps. The purposes of this study were to (1) examine whether butorphanol tartrate (Stadol; Anaquest, Madison, WI/Bristol-Meyers Squibb, Evansville, IN), meperidine (Demerol; Winthrop, NY, NY), and morphine are differentially effective in suppressing PS, (2) compare PS suppression by sex, and (3) determine time to PS development. PS, measured on a 0 to 3 visual scale, developed in 120 of 533 patients (23%). Medication treatment was initiated for 66 of 120 patients by PACU nurses following standard policies and procedures for intravenous doses of 1 mg butorphanol (n = 12), 15 to 30 mg meperidine (n = 18; n = 23), or 2 to 4 mg morphine (n = 13). Treatment effect was measured in units on a 0 to 2 visual scale. By t test, butorphanol is more effective within 2 minutes than meperidine for suppressing shaking alone (P less than .02) or shaking among patients also complaining of pain (P less than .02). Morphine does not relieve shaking. The chi 2 test indicates women suppress PS more rapidly than men (P less than .01), and PS develops within 5 minutes of PACU arrival (P less than .001). Findings suggest that butorphanol is an alternative PS treatment to meperidine, since it relieves shaking within 2 to 5 minutes without producing nausea, vomiting, or recurrence of shaking.