Abstract
BACKGROUND: The management of post-operative pain while minimizing opioid use remains challenging in thoracic surgery. While intercostal nerve blocks are commonly used, the optimal multimodal approach remains unclear. OBJECTIVES: To evaluate whether adding hydromorphone caudal blockade to intercostal nerve blocks improves post-operative recovery outcomes in thoracic surgery patients. DESIGN: A prospective, double-blinded, randomized controlled trial. SETTING: Dongguan Tungwah Hospital. PATIENTS: Eighty adult patients scheduled for video-assisted thoracoscopic surgery (VATS) were enrolled. INTERVENTION: Patients were randomized to receive either ultrasound-guided caudal blockade with 1 mg hydromorphone (caudal group) or normal saline (control group) in addition to standard intercostal nerve blocks. MAIN OUTCOME MEASURES: The primary outcome was the Quality of Recovery-40 (QoR-40) score at 48 h post-surgery. Secondary outcomes included pain scores, nausea assessment, opioid consumption, vital signs, chest tube drainage, pulmonary complications, inflammatory markers, and length of hospital stay. RESULTS: The median [IQR] total QoR-40 score showed a non-significant trend favoring the caudal group (189.50 [169-194.5] vs. 181 [170.25–189.50], P = 0.134). However, significant improvements were observed in the caudal group for: nausea scores (5 [5–5] vs. 5 [4–5], P = 0.011), moderate pain (4 [4–5] vs. 4 [3–5], P = 0.014), and severe pain (5 [5–5] vs. 5 [4–5], P = 0.004). CONCLUSIONS: While hydromorphone caudal blockade did not significantly improve overall recovery scores, it demonstrated specific benefits in pain and nausea control when combined with intercostal nerve blocks for VATS procedures. TRIAL REGISTRATION: Clinical Trial Registry of China (ChiCTR2400080726 / 02/ 2024). SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12871-025-03307-4.