Randomized Trial of Poloxamer 407-Based Ropivacaine Hydrogel After Thoracoscopic Pulmonary Resection

Background We conducted a comparative study to evaluate the efficacy of poloxamer 407-based ropivacaine hydrogel at the wound site (Gel) and continuous thoracic paravertebral block (On-Q) for postoperative pain following thoracoscopic pulmonary resection. Methods This prospective, randomized, noninferiority study included 89 patients randomized into the two groups; Gel (poloxamer 407-based 0.75% ropivacaine, 22.5 mg) and On-Q (0.2% ropivacaine, 4 mg/hour for 48 hours). The primary outcome measure was total fentanyl consumption and secondary outcome measures were the need for rescue analgesia and pain intensity using the numeric rating scale (NRS). Results There was no significant difference in total fentanyl consumption between the Gel group and the On-Q group (1504.29 ± 315.72 mcg vs 1560.32 ± 274.81 mcg, p = 0.374). Pain intensity using the NRS between the Gel group and the On-Q group demonstrated no statistical differences (6 hours: 3.56 vs 3.55, p = 0.958; 24 hours: 3.21 vs 3.00, p = 0.250; 48 hours: 2.75 vs 2.49, p = 0.233; and 72 hours: 2.39 vs 2.33, p = 0.811), and there was no significant difference in the frequency of analgesic rescue medication use (3.70 vs 3.33, p = 0.417). Conclusions We confirm the noninferiority of Gel compared with On-Q for acute postoperative pain following thoracoscopic pulmonary resection. Considering a technical simplicity and low systemic toxicity of the local injection of Gel, this analgesic modality may be worthy of further research and is thus considered to have potential as a viable alternative to On-Q for regional analgesia.