A randomised controlled trial of lidocaine infusion on post-operative opioid consumption in patients undergoing robotic colorectal surgery.

Introduction: Intravenous lidocaine has been shown to have analgesic effects leading to a reduced post-operative opiate need, but this effect is still debated in various surgical populations. We investigated whether this effect could be demonstrated in robot-assisted colorectal surgery.

Methods: A total of 60 adult patients undergoing robot-assisted colorectal surgery were randomly assigned to two groups in this prospective, double-blinded trial. The lidocaine group was treated with intravenous lidocaine. Treatment was initiated before induction of anaesthesia with a bolus of 1.5 mg/kg and immediately followed by infusion of 1.5 mg/kg/h continued until 2 h after end of surgery. The control group received placebo treatment with an equal volume and a dosing of 0.9% saline. The follow-up period was 72 h.

Results: No significant difference between groups in the median cumulated morphine consumption at 24 and 72 h was observed. Nor were there any differences in pain score, use of antiemetics, time until flatus and/or defecation or length of hospital stay.

Conclusions: In this randomised, double-blinded, prospective study using intravenous lidocaine versus 0.9% saline in robot-assisted colorectal surgery, we found no significant difference in post-operative cumulated morphine consumption at 24 or at 72 h.

Funding: The study received funding from DASAIMs Forskningsinitiativ (2016) and DASAIMs Smerteforskningspris (2016).

Trial Registration: The trial is registered with EudraCT (2014-003466-25) and ClinicalTrials.gov (ID: NCT03044808).