Divided method of intercostal nerve block reduces ropivacaine dose by half in thoracoscopic pulmonary resection while maintaining the postoperative pain score and 4-h mobilization: a retrospective study.

Purpose: This study investigated whether the divided method of multi-level intercostal nerve block (ML-ICB) could reduce the ropivacaine dose required during thoracoscopic pulmonary resection, while maintaining the resting postoperative pain scores.

Methods: This retrospective, single-cohort study enrolled 241 patients who underwent thoracoscopic pulmonary resection for malignant tumors between October 2020 and March 2022 at a cancer hospital in Japan. ML-ICB was performed by surgeons under direct vision. The differences in intraoperative anesthetic use and postoperative pain-related variables at the beginning and end of surgery between group A (single-shot ML-ICB; 0.75% ropivacaine, 20 mL at the end of the surgery) and group B (divided ML-ICB, performed at the beginning and end of surgery; 0.25% ropivacaine, 30 mL total) were assessed. The numerical rating scale (NRS) was used to evaluate pain 1 h and 24 h postoperatively.

Results: Intraoperative remifentanil use was significantly lower in group B (14.4 ± 6.4 μg/kg/h) than in group A (16.7 ± 8.4 μg/kg/h) (P = 0.02). The proportion of patients with NRS scores of 0 to 3 at 24 h was significantly higher in group B (85.4%, 106/124) than in group A (73.5%, 86/117) (P = 0.02). The proportion of patients not requiring postoperative intravenous rescue drugs was significantly higher in group B (78.2%, 97/124) than in group A (61.5%, 72/117) (P < 0.01).

Conclusion: The divided method of ML-ICB could reduce the intraoperative remifentanil dose, decrease the postoperative pain score at 24 h, and curtail postoperative intravenous rescue drug use, despite using half the total ropivacaine dose intraoperatively.