Epidural droperidol reduces the side effects and duration of analgesia of epidural sufentanil.

The postoperative combination of epidural sufentanil and epidural droperidol was assessed in 40 patients with hip or knee arthroplasties. Patients were given a single intravenous (i.v.) bolus of sufentanil 50 micrograms with either droperidol 2.5 mg or placebo (0.9% NaCl) epidurally in a double-blind, randomized design at the first request for postoperative analgesia. Pain scores, side effects, and sufentanil plasma concentrations were regularly assessed for 5 h after injection. Heat pain thresholds were measured pre- and postoperatively. The incidence of nausea, emesis, and pruritus associated with epidural sufentanil was decreased by epidural droperidol (P < 0.01, P < 0.001, P < 0.05, respectively). More patients were sedated with epidural droperidol than with placebo (P < 0.02). The initial reduction in pain scores was similarly profound, but the duration of analgesia after sufentanil and droperidol was significantly shorter than after sufentanil and placebo (P < 0.02). Phasic and tonic heat pain thresholds were increased postoperatively 1 h after sufentanil and placebo (P < 0.01 and P < 0.0005, respectively). Only the tonic heat pain thresholds were increased 1 h after sufentanil and droperidol (P < 0.002). The addition of epidural droperidol significantly reduced the excitatory side effects of epidural sufentanil while diminishing the duration of analgesia. These interactions may be of clinical significance in reducing the toxicity of opioids, but the effect on duration of analgesia must be considered when repeated doses of opioids are prescribed.