Continuous infusion of local anesthetic at the site of the abdominal surgical wound for postoperative analgesia: a systematic review

Objectives: We present a systematic review of clinical trials to evaluate the efficacy of infusing local anesthetic through a catheter placed in the abdominal surgical wound. Methods: The Jadad (Oxford) scoring system was used to select trials. The variables considered in relation to each trial selected were as follows: type of intervention and incision; type, dose, and concentration of local anesthetic; site where the catheter was placed; rescue analgesia required; opioid use; and incidence of adverse events. Results: Fifteen clinical trials with a mean Jadad score of 4.6 were selected. The 1139 patients enrolled in the trials were grouped according to catheter placement: subfascial (6 trials), subcutaneous (8 trials), and both (1 trial). Six additional unpublished trials registered at ClinicalTrials.gov were also located. Conclusions: Surgical wound analgesia is a safe technique whose effectiveness has been observed in cesarean sections and hysterectomies performed with Pfannenstiel incisions. Outcomes for other types of surgery are inconsistent. There is a lack of studies of the optimal site for catheter placement as well as of adequate anesthetic concentration and volume.