Wound infusion with local anaesthesia after laparotomy: a randomized controlled trial Louis William Wang,† Shing Wai Wong,†‡ Philip John Crowe,†‡ Kok Eng Khor,§ Grazyna Jastrzab,§ Andrew David Parasyn† and William Robert Walsh‡¶ †Department of Surgery, Prince of Wales Hospital, New South Wales, Australia ‡University of New South Wales §Department of Pain Management, Prince of Wales Hospital, New South Wales, Australia ¶Surgical and Orthopaedic Research Laboratories, Prince of Wales Hospital, New South Wales, Australia Key words anaesthesia, local, analgesia, patient-controlled, pain, post-operative, laparotomy, randomized controlled trial. Abbreviations PCA, patient-controlled analgesia; CI, confidence interval; D.F., degrees of freedom. Correspondence Dr Shing Wong, Department of Surgery, Prince of Wales Hospital, Randwick, NSW 2031, Australia. Email: sw.wong@unsw.edu.au L. W. Wang BSc(Med), MBBS(Hons); S.W. Wong MS, FRACS; P.J. Crowe DPhil, FRACS; K.E. Khor MMed(PM), FFPMANZCA; G. Jastrzab RN, MNEd; A.D. Parasyn MBBS FRACS; W.R. Walsh PhD. This research was presented at the Australia and New Zealand Medical and Surgical Gastrointestinal Week 2009, Sydney, Australia on 23rd October 2009. Accepted for publication 11 August 2009 doi: 10.1111/j.1445-2197.2010.05339.x Abstract Background: The use of a continuous local anaesthesia infusion after laparotomy may reduce opioid requirements and facilitate earlier return of bowel function, inde- pendent 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 statisti- cally significant after adjusting for age, gender and type of operation (P = 0.0006). Ropivacaine infusion was associated with a significantly decreased time to indepen- dent mobilization (P = 0.02), time to first flatus (P = 0.02) and reduced post-operative ileus (2/28 versus 9/27, c 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 anal- gesia. This improves patient recovery through earlier return to bowel function and mobilization. Introduction Infiltration of surgical wounds with local anaesthesia provides anal- gesia by preventing the depolarization of nerve axons required during nerve transmission. 1 This effect has a limited duration of action, and as a result, continuous infusions of local anaesthesia have been used to achieve sustained analgesia. Intravenous opioids, on the other hand, act on multiple sites in both the central and peripheral nervous system to inhibit transmission of nociceptive stimuli. 2,3 Although opioids are frequently used for the treatment of post- operative pain following laparotomy, their use is often associated with troublesome side effects. 4 These include nausea, vomiting, over-sedation, confusion and delayed return of post-operative bowel function. Multi-modal treatment of post-operative pain is now the gold standard treatment for post-operative analgesia following lap- arotomy and is thought to improve analgesia by providing multiple mechanisms for reducing nociception and transmission. 5 Side effects related to toxicity are reduced because the amount of each agent required to achieve analgesia is less when it is used in combination with other agents. Despite the theoretical advantages of multi-modal treatment for post-operative analgesia following laparotomy, opinion regarding ORIGINAL ARTICLE ANZJSurg.com © 2010 The Authors ANZ Journal of Surgery © 2010 Royal Australasian College of Surgeons ANZ J Surg 80 (2010) 794–801