Comparison of dexmedetomidine and dexamethasone for prevention of postoperative nausea and vomiting after laparoscopic cholecystectomy

Abstract

Background: Postoperative nausea and vomiting (PONV) are common following laparoscopic cholecystectomy (LC). Dexamethasone has been reported to reduce PONV. However, there is insufficient evidence regarding the effect of dexmedetomidine in decreasing PONV. This study was designed to compare the effects of a single dose of dexmedetomidine to dexamethasone for reducing PONV after LC.

Methods: Eighty-six adult patients scheduled for LC were randomized to receive either single dose 1 µg/kg of dexmedetomidine (Dexmed group, N = 43) or 8 mg dexamethasone (Dexa group, N = 43) before skin incision. During the first 24 h postoperatively, the incidence and severity of PONV were assessed. Pain and sedation scores were assessed on arrival in the recovery room and early postoperatively. Analgesic and antiemetic consumption during the 24 h after surgery were calculated. Intra-operative and postoperative hemodynamics were recorded.

Results: Twenty-one percent of the patients in the Dexmed group developed PONV compared to 28% in the Dexa group (P = 0.6). Severity of PONV was similar between the two groups (P = 0.07). Early postoperatively, pain severity was significantly lower in the Dexmed group, but sedation scores were significantly higher. The first analgesic request was significantly delayed in the Dexmed group (P = 0.02). The total amounts of intraoperative fentanyl and postoperative tramadol administered were significantly lower in the Dexmed group. No difference in ondansetron was noted between the two groups. Mean arterial pressure and heart rate were significantly lower in the Dexmed group after administration of dexmedetomidine. No major side effects were reported.

Conclusions: Dexmedetomidine reduces the incidence and severity of PONV, similar to dexamethasone. It is superior to dexamethasone in reducing postoperative pain and total analgesic consumption during the first 24 h after LC.

Keywords: Cholecystectomy; Dexamethasone; Dexmedetomidine; Laparoscopy; Postoperative nausea and vomiting.

Fig. 1. Comparison of postoperative visual analogue scale (VAS) of pain between both groups. T0: on arrival at post-anesthesia care unit (PACU), (T1-T10): hourly for the next 10 h. The severity of pain was significantly lower (P < 0.05) in the Dexmed group on arrival at PACU and during the first 4-h assessment after arrival at the PACU compared to the Dexa group. No significant changes occurred after that (P > 0.05).

Fig. 2. Perioperative changes in mean arterial blood pressure in both groups. T0: just before giving study medication; T1: 5 min after study medication; T2: 30 min after study medication; T3: 5 min after extubation; T4: on arrival at the PACU; and then hourly for the next 6 h (T5-10). The mean arterial blood pressure was significantly lower (P < 0.05) in the Dexmed group after administration of dexmedetomidine till arrival at post-anesthesia care unit, but no significant changes occurred after that (P > 0.05).

Fig. 3. Perioperative changes in heart rate in both groups. T0: just before giving study medication; T1: 5 min after study medication; T2: 30 min after study medication; T3: 5 min after extubation; T4: on arrival at post-anesthesia care unit (PACU); and then hourly for the next 6 h (T5-10). The heart rate was significantly lower (P < 0.05) in the Dexmed group after administration of dexmedetomidine till 2 h after arrival at PACU, but no significant changes occurred after that (P > 0.05).