Application of lidocaine in alleviating breakthrough pain during epidural labor analgesia in obese primiparas

Objective To evaluate the clinical efficacy of lidocaine in alleviating breakthrough pain during labor in obese primiparas and its effect on maternal and infant outcomes. Methods A total of 120 obese primiparas (body mass index being 35 to 45 kg/m2) underwent epidural analgesia during delivery at Nanjing Women and Children’s Healthcare Hospital from October 2022 to December 2023 were selected and all primiparas experienced breakthrough pain during the first stage of labor. All patients were randomly divided into two groups, with 60 cases in each group. The experimental group received 6 mL of 1.0% lidocaine administered by epidural injection when breakthrough pain occurred (VAS score≥4), while the control group received 6 mL of 0.15% ropivacaine by epidural injection. The following parameters were recorded: time for VAS scores decreasing to 3 or below, cervical dilation at the onset of the first breakthrough pain, number of additional drug administrations during labor, VAS scores at various time points, delivery-related outcomes (duration of labor, use rate of oxytocin, blood loss within 2 hours after delivery, mode of delivery), and adverse events during analgesia. Results Compared with the control group, the experimental group had a shorter time for the VAS score decreasing to 3 or below [7(6,7) min vs 16(16,17) min, Z=52.624, P＜0.01]. There was no statistically significant difference in the cervical dilation at the onset of the first breakthrough pain and number of additional drug administrations during labor (P＞0.05). At 5 min (T1), 10 min (T2), and 15 min (T3) after administration, the VAS scores of the experimental group were lower than those of the control group (P＜0.05). There was no statistically significant difference in the duration of labor, usage rate of oxytocin, blood loss within 2 hours after delivery, mode of delivery, and adverse events during analgesia between the two groups (P＞0.05). Conclusion Both 6 mL of 1.0% lidocaine and 6 mL of 0.15% ropivacaine administered by epidural injection can effectively suppress breakthrough pain in obese parturient during epidural labor analgesia, and improve maternal and neonatal outcomes. And lidocaine demonstrates a shorter onset time, and a faster decrease in VAS score.