# Postoperative Pain Control After Cesarean Section by Continuous Infusion Pump System Versus Ropivacaine Hydrogel: A Prospective Randomized Clinical Trial

## TL;DR

This study compared two methods for managing pain after cesarean sections and found both effective, but the hydrogel was easier to use and required less anesthetic.

## Contribution

A novel thermosensitive ropivacaine hydrogel is proposed as a practical alternative to catheter-based analgesia for post-cesarean pain.

## Key findings

- Pain scores were similar between hydrogel and catheter groups at all time points.
- Hydrogel delayed the first request for NSAIDs and increased cumulative NSAID use.
- Hydrogel required a lower total anesthetic dose and had no catheter-related complications.

## Abstract

Objective: The objective of this study was to evaluate the efficacy of a ropivacaine-loaded poloxamer 407 (P407)-based thermosensitive hydrogel applied at the subfascial site compared with a continuous local anesthetic delivery system using a catheter for postoperative pain control after cesarean section (CS), in combination with standard intravenous patient-controlled analgesia (IV-PCA). Methods: This single-center, prospective randomized controlled trial included 72 pregnant women undergoing CS between April and October 2025. Participants were randomly assigned to receive either ropivacaine hydrogel or catheter-based ropivacaine infusion, both in conjunction with IV-PCA. Primary outcomes included numeric rating scale (NRS) pain scores at 3, 6, 12, 24, and 48 h postoperatively. Secondary outcomes included the time to first NSAID request and the cumulative use of rescue NSAIDs. Results: There were no significant differences in baseline characteristics between the groups. NRS pain scores did not differ significantly at any time point, although they varied significantly over time within each group. The hydrogel group showed a statistically significant delay in the time to first NSAID request (6.3 ± 5.1 h vs. 5.0 ± 6.1 h, p = 0.049) and higher cumulative NSAID use (2.4 ± 1.7 vs. 1.6 ± 1.2, p = 0.035). No serious complications were observed in either group. Conclusion: The ropivacaine hydrogel provided postoperative pain control comparable to that of the continuous catheter system, with no statistically significant differences in NRS scores observed between groups. Given its ease of use, absence of catheter-related concerns, and substantially lower total anesthetic dose, the P407-based hydrogel may represent a practical and patient-friendly alternative for post-cesarean analgesia.