Erector spinae plane block vs. opioid‐based regimen: a reply

We thank Jin et al. [1] and Yang [2] for their interest in our study of the analgesic efficacy of continuous erector spinae plane block vs. an opioid-based regimen for postoperative pain management following video-assisted thoracoscopic lung resection [3]. Regarding the comments from Jin et al. [1], the non-inferiority margin was set at 8% of the cumulative area under the curve in the control group, corresponding to a value of 11.86. This translates to an average difference of approximately 0.25 on the numerical rating scale for each hour of the 48-h study period. Thus, any difference ≤ 0.25 points, which is less than the minimal clinically important difference, remains clinically acceptable. To mitigate the risk of expectation bias, ward nurses not involved in peri-operative care were trained and collected all data. We used real-time data monitoring and weekly audits to ensure protocol compliance. Segmentectomies in this study were unplanned and resulted in comparable surgical trauma. While segmentectomy preserves more lung parenchyma, its impact on chest wall structures and postoperative pain is anatomically similar to that of lobectomy. We argue the inclusion of these patients did not influence the outcomes materially and that the non-inferiority conclusion remains valid. While a marked reduction in postoperative pulmonary complications was observed in the erector spinae group, this outcome was secondary and assessed without blinding. This finding should be interpreted as hypothesis-generating rather than conclusive. Although serum ropivacaine levels were not measured, all patients were monitored for clinical signs of local anaesthetic systemic toxicity. No such events were observed throughout the study period. We therefore consider our dosing regimen (approximately 775 mg over 48 h) to be clinically safe under monitored conditions. Regarding the comments from Yang [2], we acknowledge that the limited number of postoperative pulmonary complications (n = 26) falls below the recommended threshold of at least 10 events per predictor variable, which may affect the stability and generalisability of the multivariable model. To mitigate the risk of overfitting and enhance model reliability, candidate variables were restricted to those with strong clinical justification and a univariable association of p < 0.05. No exploratory model-building practices were employed. Following backward elimination, only continuous erector spinae plane blockade and previous chemotherapy were significant predictors. Our unadjusted analysis showed a significant reduction in postoperative pulmonary complications with continuous erector spinae blockade. The multivariable result showed a substantial reduction, which we argue has biological plausibility. However, these results should be interpreted cautiously and viewed as exploratory. They are intended to generate hypotheses for future validation in larger, appropriately powered studies. We agree that the observed differences of 1–1.5 h in early ambulation and time to oral intake did not translate into a reduction in duration of hospital stay, and that the implications of these differences within an enhanced recovery context should be interpreted cautiously. Hospital duration of stay is influenced by a wide range of non-clinical factors, including institutional discharge protocols; bed availability; and social circumstances. Thus, the absence of a difference in duration of stay does not necessarily reflect there being no difference in recovery quality. However, the consistent acceleration of functional recovery outcomes supports the value of continuous erector spinae plane blockade as part of a multimodal analgesia strategy, warranting further investigation in pragmatic, real-world settings. Our study did not include a formal economic analysis. However, once the block technique is mastered, it can be applied to various surgical procedures, yielding potential benefits elsewhere. Furthermore, by potentially reducing postoperative complications, continuous erector spinae plane blockade may also shorten hospital stays and reduce complication-related costs and, therefore, have considerable potential for long-term cost-effectiveness.