We read with great interest the prospective randomized trial by Dey et al. [1] evaluating the effect of adding dexmedetomidine or morphine to 0.2% ropivacaine for myofascial infiltration on postoperative analgesia in thoracolumbar spinal fusion. The authors should be commended for addressing a clinically relevant question in the field of multimodal analgesia for spine surgery. We believe that the following two points may offer helpful perspectives for interpreting their findings and designing future studies.

First, a point of clarification regarding the rescue analgesia protocol may be worth considering. The authors describe in the Methods section: “Fentanyl infusion (1 mcg/kg/hr) was administered for breakthrough pain when the patients complained of a Visual Analog Scale (VAS) score of ≥3” [1]. Based on this protocol, and considering the mean body weight of the study population (ranging from 71–73 kg across the three groups), a 70 kg patient who triggered the infusion at postoperative hour 2 would receive approximately 1,540 mcg of fentanyl by the end of the 24-hour period. However, Table 3 shows that the mean 24-hour postoperative fentanyl consumption in the plain ropivacaine group—the group with the highest pain burden—was 403.18±132.18 mcg [1]. This apparent discrepancy may benefit from further clarification. It would be helpful to clarify whether all patients who triggered the infusion received the continuous infusion for the full duration, or whether the infusion was discontinued once pain was controlled. Providing additional details on the number of patients who triggered the infusion and the actual duration of infusion would help readers more accurately interpret the primary endpoint.

Second, the handling of VAS scores in the analysis may be worth revisiting. The authors calculated a “mean total VAS score” by summing ordinal VAS scores across 11 postoperative time points [1, Table 2]. VAS is an ordinal scale, where the numerical values represent the rank order of pain intensity but the intervals between values may not represent equal physiological increments. From a measurement perspective, summing ordinal data across time points can be challenging to interpret [2,3]. Area under the curve or time-weighted average are commonly used metrics for repeated pain measurements in longitudinal pain studies [2,3]. We suggest that the authors consider applying these methods in future studies or data re-analyses to strengthen the robustness of their conclusions.

We believe that these methodological considerations do not diminish the clinical value of the study. Rather, they are intended to provide reference for future research. The selection of adjuvants for local infiltration is an important topic in multimodal analgesia for spine surgery, and the exploratory work by Dey et al. [1] has contributed valuable experience to this field. We look forward to further well-designed, methodologically rigorous clinical studies to better inform clinical prac