Assessing postoperative analgesic efficacy of anterior quadratus lumborum block for laparoscopic colorectal surgery

Coppens et al. showed that the addition of a bilateral anterior quadratus lumborum block to a standard multimodal analgesia strategy did not decrease total opioid consumption or improve postoperative pain control [1]. However, the authors did not describe whether local anaesthetic wound infiltration was performed before incision or at the end of surgery. In patients undergoing laparoscopic colorectal resection, local anaesthetic wound infiltration has been shown to be non-inferior to infiltration plus transversus abdominis plane block in terms of postoperative pain control; analgesic consumption; return of bowel function; postoperative complications; and duration of hospital stay [2]. Thus, we are concerned that this unknown factor may have biased their main findings. Furthermore, the numerical rating scale (NRS) pain scores at all observed time-points were not significantly different between groups. We note that the NRS pain scores had very large ranges, especially in the first 3 h of the post-anaesthesia care unit stay. Available evidence indicates that pain levels after laparoscopic colorectal surgery are more severe during movement than at rest [3, 4], but the authors did not state the patients' status when postoperative pain was evaluated. [3, 4]. We argue that this unknown factor could have confused the results of pain assessment. Finally, in discussion, it is stated that patients did not mobilise until the first postoperative day, as mobilisation can increase pain and, potentially, opioid requirements. In fact, pain control is crucial to the success of rapid recovery after laparoscopic colorectal surgery [5]. Time to mobilisation is an important variable of patient comfort outcomes recommended by the Standardised Endpoints initiative [6]. As a result of this design limitation, a crucial question that this study cannot answer is whether addition of a bilateral anterior quadratus lumborum block to a standard multimodal analgesia strategy enhances early mobilisation and functional recovery of patients undergoing laparoscopic colorectal surgery by improving pain control on movement.