Wound infusion with local anaesthesia after laparotomy: a randomized controlled trial.

Background: The use of a continuous local anaesthesia infusion after laparotomy may reduce opioid requirements and facilitate earlier return of bowel function, independent mobilization and hospital discharge.

Methods: We performed a double-blinded, randomized controlled trial on 55 patients who underwent laparotomy. Patients were randomly allocated to receive a continuous infusion of either 0.2% ropivacaine or normal saline into their midline abdominal wound at the fascial level. The end points of the study were: total opioid requirements at 24 and 48 h; time to first flatus, bowel movement and independent ambulation; length of hospital stay; complications; and daily mean patient-reported pain scores at rest and movement.

Results: The two treatment groups were well controlled for factors that influence analgesia requirements, including age, weight, length of wound incision and type of operation. Patients allocated to ropivacaine infusion used, on average, 32 mg less morphine at 48 h (95% confidence interval 7, 57; P= 0.01). This was highly statistically significant after adjusting for age, gender and type of operation (P= 0.0006). Ropivacaine infusion was associated with a significantly decreased time to independent mobilization (P= 0.02), time to first flatus (P= 0.02) and reduced post-operative ileus (2/28 versus 9/27, χ(2) = 5.89, P= 0.02). There was no significant effect of ropivacaine infusion on time to first bowel movement (P= 0.94) nor length of hospital stay (P= 0.77).

Conclusions:   Local anaesthesia infusion at the fascial plane provides effective analgesia. This improves patient recovery through earlier return to bowel function and mobilization.