Yibing Yu,1,* Qingsong Zhao,1,2,* Yu Zang,1,3 Zhiqiang Liu,4 Weijia Du4 

1Department of Anaesthesiology, Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai, People’s Republic of China; 2Department of Anesthesiology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, People’s Republic of China; 3Department of Anaesthesiology, Yangpu Hospital, School of Medicine, Tongji University, Shanghai, People’s Republic of China; 4Department of anesthesiology, Obstetrics & Gynecology Hospital of Fudan University, Shanghai Key Lab of Reproduction and Development, Shanghai Key Lab of Female Reproductive Endocrine Related Diseases, Shanghai, 200433 People’s Republic of China

*These authors contributed equally to this work

Correspondence: Weijia Du, Department of Anesthesiology, Obstetrics & Gynecology Hospital of Fudan University, Shanghai Key Lab of Reproduction and Development, Shanghai Key Lab of Female Reproductive Endocrine Related Diseases, Shanghai, 200433, People’s Republic of China, Email duweijia10317@fckyy.org.cn Zhiqiang Liu, Department of Anesthesiology, Obstetrics & Gynecology Hospital of Fudan University, Shanghai Key Lab of Reproduction and Development, Shanghai Key Lab of Female Reproductive Endocrine Related Diseases, Shanghai, 200433, People’s Republic of China, Email drliuzhiqiang@163.com

Purpose: To compare analgesic outcomes between single- and multi-orifice epidural catheters at a 360-mL/h delivery rate during programmed intermittent epidural bolus.
Patients and Methods: In this prospective randomized double-blinded controlled trial, 102 healthy nulliparous parturients requesting labor analgesia at the Shanghai First Maternity and Infant Hospital were enrolled from July to September 2023. Participants were given either single- or multi-orifice catheters for epidural analgesia (0.1% ropivacaine with 0.3 μg/mL of sufentanil; 10 mL every 45 min at 360 mL/h). The primary outcome was ropivacaine consumption per hour, calculated as the total amount of ropivacaine administered divided by the duration of labor analgesia (mg/h).
Results: Median ropivacaine consumption per hour was not significantly different: 12.6 mg/h [11.6– 13.2 mg/h] for single-orifice vs 12.8 mg/h [12.3– 13.3 mg/h] for multi-orifice catheters (difference 29%; 95% confidence interval [CI], – 10.2 to 68.2%; P=0.241). No significant differences were found in patient-controlled epidural analgesia boluses requested and delivered, time to first bolus request, or the number of clinician-administered boluses. However, adequate analgesia at 20 min was higher with single-orifice catheters (84.0% vs 63.5%, difference 22.5%; 95% CI: 9.2% to 35.1%, P=0.019). Median times to adequate analgesia were 8 min [4– 16] vs 15 min [9.5– 22.5] for single- and multi-orifice catheters (P=0.002). Pain scores differed only at 6 and 18 min. There were no differences in the incidence of motor or unilateral block, side effects, maternal satisfaction, or catheter-related complications between the two groups.
Conclusion: Single-orifice catheters did not enhance analgesia quality during labor maintenance under a 360-mL/h programmed intermittent epidural bolus delivery rate but were linked to more rapid analgesic onset than multi-orifice catheters.

Keywords: labor analgesia, programmed intermittent epidural bolus, neuraxial anesthesia, labor