Infusión de morfina para el manejo del dolor postoperatorio en pacientes sometidos a cirugía abdominal alta / Morphine infusion for postoperative pain management in patients subjected to upper abdominal surgery

ABSTRACT

We compared the efficacy and side effects of postoperative continous infusions versus intermittent intravenous on-demand morphine, with or without the addition of clonixin. Eighty five helthy patients, aged 18 to 65 years, scheduled for elective cholecystectomy were prospectively randomized: group 1 (n=22) received morphine 2,5 mg iv on-demand; group 2 (n=22) received a clonixin 400 mg/day iv infusion; group 3 (n=19) a morphine 0,4 mg/kg/day iv infusion; and group 4 (n=22) received a clonixin 400 mg/day plus a morphine 0,4 mg/kg/day iv infusion. Groups 2, 3 and 4 also received, on-demand 2,5 mg iv bolus doses of morphine. A blind observer recorder analogue and descriptive pain scores, respiratory rates and side effects for 72 hours postoperatively. Groups with morphine infusions had less overall pain scores for the first day when compared with intermitent dosing (p<0.05); these groups also had less pain during the night (p=0.0016) and required less aditional morphine (p<0.0001). Side effects were similar and no cases of heavy sedation or respiratory depression were observed. We conclude that a morphine 0.4 mg/kg/day infusion is a safe and effective alternative to on demand dosing in helathy patients after elective cholecystectomy, achieving better analgesia without increasing side-effects. Clonixin 400 mg/day seems to add no significant benefits