Dear Editor,

I read with great interest the study of Ng et al. in a recent issue of the Journal [1]. The authors should be congratulated for developing a multimodal protocol to address postsurgical pain in patients undergoing bariatric surgery. Postsurgical pain remains to be very common and poorly treated, especially in obese patients with obstructive sleep apnea [2, 3].

Despite its clinical relevance, methodological issues with the study of NG et al. need to be further clarified in order to confirm or refute the validity of the authors’ findings. First, the authors do not report on other concomitant multimodal analgesic strategies (e.g., non-steroidal anti-inflammatory drugs, regional anesthesia nerve blocks, local anesthetic infiltration) that can significantly alter the study results [4,5,6]. In addition, the intraoperative anesthesia technique is not reported. It is possible that the use of remifentanil in some patients may have resulted in hyperalgesia which can significantly increase postsurgical pain [7]. Lastly, the authors did not control for surgical duration and this can significantly influence the intensity of pain after surgery [8].

I would welcome some comments from the authors that would allow readers to be confident in the validity of this very important study.

Sincerely,