Two‑stage diphenhydramine improves early recovery in women after video‑assisted thoracoscopic surgery: a randomized controlled trial.

PURPOSE: Thoracic paravertebral block (TPVB) provides effective analgesia for video-assisted thoracoscopic surgery (VATS). However, even when pain is well-controlled by TPVB, female patients remain at high risk for postoperative nausea and vomiting (PONV) and sleep disturbances because of non-analgesic factors, such as hormonal and central emetic pathways. We investigated whether adding a two-stage diphenhydramine regimen to TPVB-based multimodal analgesia improves early recovery quality.

METHODS

In this prospective, randomized, double-blind, placebo-controlled trial, 80 women (ASA I-III) scheduled for elective VATS pulmonary resection were randomized to receive a two-stage diphenhydramine regimen (0.2 mg/kg bolus at chest closure followed by 0.5 mg/kg via postoperative patient-controlled intravenous analgesia [PCIA]) or placebo (normal saline). All patients received standardized TPVB with 20 mL 0.4% ropivacaine, PCIA with sufentanil/ondansetron, and intravenous dexamethasone 10 mg. The primary outcome was the 24-h Quality of Recovery-15 (QoR-15) score. Secondary outcomes included sleep quality, PONV incidence, pain scores, rescue medication requirements, and adverse events.

RESULTS

The diphenhydramine group exhibited a significantly higher median 24 h QoR-15 score (127 [IQR 121-134.75] vs. placebo 119.5 [IQR 108.25-130.75], P = 0.033). This group also demonstrated markedly better sleep quality (lower Athens Insomnia Scale scores at 24 and 48 h, P < 0.05) and a significantly reduced incidence of vomiting (10% vs. 40%, P = 0.004). Overall PONV rates and other secondary outcomes were comparable, with no difference in adverse events.

CONCLUSIONS

Adding a two-stage diphenhydramine regimen to TPVB-based multimodal analgesia significantly improves early recovery quality, enhances postoperative sleep, and reduces vomiting in women after VATS, without increasing adverse events.

CLINICAL TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR2500097837).