Ultrasound-guided transversus abdominis plane blocks for laparoscopic appendicectomy in children: a prospective randomized trial

Background. The effect of adding transversus abdominis plane (TAP) blocks to local anaesthetic infiltration on morphine consumption and postoperative pain in children undergoing laparoscopic appendicectomy is unknown. Methods. After random allocation, 93 children aged 7-16 were randomized to receive ultrasound-guided TAP blocks placed before surgery or not (control). All subjects had port sites infiltrated with ropivacaine and were prescribed i.v. patient-controlled analgesia (PCA) with morphine and oral paracetamol for postoperative pain. The primary outcome was the proportion of subjects using > 200 mu g kg(-1) morphine. Secondary outcomes included PCA morphine use, pain scores, time intervals to the first use of PCA and other analgesics, sedation scores, postoperative nausea or vomiting, and time to hospital discharge. Results. The procedure duration was longer in the TAP group (111 compared with 97 min for controls, P=0.03). The duration in the recovery ward and that of the hospital stay were similar. There was no difference in the proportion of subjects requiring > 200 mu g kg(-1) of PCA morphine [control 31/45 (69%), TAP 29/42 (69%), P=0.99]. There was no significant difference in PCA morphine use, time intervals to the first use of PCA or other analgesics, or amounts of other analgesics. More patients in the TAP group had complicated appendicitis [TAP 13/42 (31%), control 5/45 (11%), P=0.02]. Pain scores were reduced for the TAP group in the recovery ward only (median score 0 vs 2, 95% confidence interval 0-3, P=0.03). Conclusions. TAP blocks increased anaesthesia time by 14 min on average but offered no clinically important benefit over local anaesthetic port-site infiltration to paediatric patients undergoing laparoscopic appendicectomy.