Study of the Effect of Pre-operative Single Dose Intravenous Dexamethasone on Peak Expiratory Flow Rate and Post Operative Analgesia after Laparoscopic Cholecystectomy

Background: Surgical trauma although less in laparoscopic cholecystectomy compared to open cholecystectomy, still provokes neuroendocrinal stress response causing significant post operative pain with visceral, parietal and shoulder components. Methods: 80 patients aged 20-50 years of ASA physical status I and II were randomly allocated into two groups of 40 each. The patients in group D received 2 ml (8 mg) intravenous (i.v) dexamethasone 90 minutes before skin incision. The patients in group C received 2 ml of normal saline i.v. over same period. Intensity of surgical site pain at rest, at deep inspiration and shoulder pain was assessed at 2, 6, 12 and 24 hours post surgery using Visual Analogue Scale (VAS). Analgesic consumption was also recorded. Peak expiratory flow rate was compared in both the groups at baseline, 6, 12 and 24 hours post surgery. Results: Dexamethasone significantly reduced dynamic component of incisional pain at 2 hours, visceral pain at 2 hours at rest (p = 0.003) and coughing (p = 0.000) and also at 6 hours on coughing (p = 0.001), reducing significantly the overall analgesic consumption (37.5 ± 37.98 mg in dexamethasone group and 101.25 ± 60.168 mg in the Control group. p = 0.000). Dexamethasone significantly improved post operative pulmonary function (p < 0.05). Conclusion: Single dose 8 mg dexamethasone given 90 minutes before skin incision in patients undergoing laparoscopic cholecystectomy is associated with lesser reductions in peak expiratory flow rate, requirement of rescue analgesics and lesser incidence of post operative nausea and vomiting.