The influence of a prophylactic dose of dexamethasone for postoperative nausea and vomiting on plasma interleukin concentrations after laparoscopic cholecystectomy: a randomised trial.

BACKGROUND: Little is known about the effects of small doses of dexamethasone used for the prophylaxis of postoperative nausea and vomiting on the innate host response. OBJECTIVES: We studied the influence of dexamethasone 4 mg on the perioperative plasma concentrations of interleukins after laparoscopic cholecystectomy. We hypothesised that there would be differences in pro-inflammatory interleukin concentrations in patients who received dexamethasone. DESIGN: A randomised controlled study. SETTING: University hospital. PATIENTS: Forty-six patients undergoing laparoscopic cholecystectomy under total intravenous anaesthesia were allocated randomly into one of two study groups; 42 patients completed the study. INTERVENTIONS: Patients in group 1 (dexamethasone, n = 22) received dexamethasone 4 mg and group 2 (n = 20) acted as controls. MAIN OUTCOME MEASURES: Plasma levels of tumour necrosis factor alpha and interleukins 1ß, 6, 8, 10 and 13 were measured before anaesthesia, before surgery and 2 and 24 h after surgery. The frequency and number of episodes of postoperative nausea and vomiting were recorded. RESULTS: Areas under the curve of the percentage variation of interleukins 6 and 8 were significantly lower in the dexamethasone group. There were no significant differences between groups in the areas under the curve for tumour necrosis factor alpha and interleukins 1ß, 10 and 13. The greatest variation in interleukin concentrations was 2 h postoperatively, when the concentration of interleukin 6 was greater in the control group, whereas the concentration of interleukin 10 was higher in the dexamethasone group. Twenty-four hours after surgery, only the concentration of interleukin 6 remained significantly increased in both groups (P = 0.001 and P = 0.002, respectively). There were no significant differences between groups in respect of postoperative nausea and vomiting. CONCLUSION: Prophylactic dexamethasone given before laparoscopic cholecystectomy produced a significant decrease in concentrations of interleukins 6 and 8. Further studies are needed to investigate the clinical implications of these findings.