Influence of different positioning of a local pain catheter on postoperative pain after paramedian laparotomy-a blinded, randomized trial

Continuous application of local anaesthetics reduces postoperative pain after different approaches for laparotomy. In this randomized, blinded trial, we investigated the effect of continuous application of local anaesthetics after paramedian laparotomy either with subfascial or subcutaneous catheter in addition to a standardized systemic analgesia. Patients with stage III/IV melanoma and indication for radical iliac lymph node dissection (RILND) were randomized to a continuous application of a local anaesthetic through either a subfascial or subcutaneous catheter. Participants and those assessing the outcomes were blinded. The main outcome criterion was the pain level on the first postoperative morning while exercising measured with a visual analogue scale. Minor criteria were the pain measured by the area-under-curve until the third postoperative day, the patient's satisfaction with analgesic treatment, the analgesic requirement, the overall complications and the day of discharge. Fifty-two patients were evaluated. Pain therapy was sufficient in both groups during the postoperative course while resting and during mobilization. There were no significant differences regarding the main and minor outcome criteria. Doses of additional analgesics did not differ between groups. No adverse events or side effects were observed. For patients who undergo paramedian laparotomy, none of the investigated techniques is superior to the other at a median pain level under visual analogue scale (VAS) 30 mm on the first postoperative morning. DRKS00003632 (German Register of Clinical Trials).