Authors: Xue F-S et al.
Source: Anesthesiology. 2025;143(6):1663–1665. DOI: 10.1097/ALN.0000000000005973
This Letter to the Editor comments on Zhang et al.’s study evaluating pyridoxine (vitamin B6) as part of a multimodal postoperative nausea and vomiting (PONV) prevention strategy in gynecologic laparoscopic surgery. Xue and colleagues acknowledge that pyridoxine was reported to halve the incidence of PONV within 24 hours; however, they argue that the conclusion may not be fully supported because several essential clinical endpoints were not assessed.
The authors first emphasize that postoperative opioid use is one of the most significant contributors to PONV. They highlight that Zhang et al.’s reported postoperative pain scores and opioid requirements were nearly identical between the pyridoxine group and the control group, suggesting that differences in PONV rates cannot be explained by differences in analgesia or opioid consumption. They note that median pain scores were well controlled in both groups and that 24-hour intravenous morphine equivalents overlapped considerably, with interquartile ranges of 0–4 mg in both groups.
They further point out that the study did not examine broader patient-centered recovery metrics included in the Standardized Endpoints in Perioperative Medicine, such as sleep quality, time to mobilization, gastrointestinal function, or quality of recovery. Because pyridoxine is thought to influence nausea pathways but not these other aspects of postoperative recovery, the authors argue that the clinical relevance of the improved PONV rate is uncertain without examining these additional outcomes.
Finally, Xue et al. question the robustness of the findings because other known variables contributing to PONV—such as anesthetic technique, intraoperative hemodynamics, and rescue antiemetic use—were not standardized or fully reported. They note that the pyridoxine group had a slightly higher incidence of intraoperative hypertension, which could be relevant. Given these limitations, they conclude that more rigorous, controlled, and endpoint-complete trials are necessary before accepting pyridoxine as a validated component of multimodal PONV prophylaxis.
What You Should Know
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This letter critiques the methodological limitations of a study suggesting benefit from pyridoxine in reducing PONV.
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Xue et al. argue that opioid use — a major driver of PONV — was equivalent between groups, weakening the proposed mechanism of benefit.
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Key postoperative recovery endpoints were not assessed, leaving uncertainty about the true clinical impact of adding pyridoxine.
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The authors ultimately call for more rigorous randomized trials before pyridoxine can be adopted into standardized PONV protocols.
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