The effects of intra-operative dexmedetomidine on postoperative pain, side-effects and recovery in colorectal surgery

In this double-blind, randomised study, 100 patients undergoing open or conventional laparoscopic colorectal surgery received an intra-operative loading dose of dexmedetomidine 1g.kg(-1) followed by an infusion of 0.5g.kg(-1).h(-1), or a bolus and infusion of saline 0.9% of equivalent volume. Forty-six patients in the dexmedetomidine group and 50 in the saline group completed the study. The area under the curve of numerical rating scores for pain at rest for 1-48h postoperatively was significantly lower in the patients receiving dexmedetomidine (p=0.041). There was no difference in morphine consumption, duration of recovery ward or hospital stay. From the data obtained in this study, we calculated a number needed to treat for effective pain relief of 4. Intra-operative dexmedetomidine in colorectal surgery resulted in a reduction in resting pain scores, but there was no morphine-sparing effect or improvement in patients' recovery outcome measures.