目的 探讨程控硬膜外间歇脉冲输注PIEB模式中不同脉冲间隔时间对初产妇和经产妇分娩镇痛效果的影响并评估其镇痛效果的差异性。 方法 分别选择60例符合纳入标准的初产妇和经产妇，各分为两组：脉冲间隔时间45 min组（P45组，n = 30）、脉冲间隔时间60 min组（P60组，n = 30）。在产妇宫口扩张至1 ~ 3 cm进行硬膜外分娩镇痛，分别于镇痛开始后45 min和60 min启动PIEB模式，单次脉冲剂量为10 mL，药物配方为0.08%罗哌卡因与0.5 μg/mL舒芬太尼混合液。通过记录镇痛开始（t0）、镇痛后1 h（t1）、镇痛后2 h（t2）、宫口开全（t3）和胎儿娩出时（t4）视觉模拟评分（VAS评分）、Bromage评分、PCA按压次数、用药总量及不良反应，评估患者的分娩镇痛效果。 结果 初产妇P45组t1时间点VAS评分显著低于P60组（P < 0.05），t2—t4时间点P45和P60组VAS评分差异无统计学意义（P > 0.05）；初产妇P45组患者PCEA按压中位数显著低于P60组患者（P < 0.05），但两组产妇PCEA用药总量、Bromage 评分及不良反应的发生情况差异无统计学意义（P > 0.05）；经产妇镇痛后P45组和P60组各个时间点的VAS评分、Bromage 评分、PCEA 按压中位数均差异无统计学意义（P > 0.05）；P45组用药总量显著高于P60组（P < 0.05）。 结论 对于初产妇，PIEB模式下45 min的脉冲间隔时间能提供更优的分娩镇痛效果，显著减少PCA按压次数，且未增加运动阻滞的风险和程度以及不良反应的发生率。对于经产妇，不同脉冲间隔时间对分娩镇痛效果无明显影响。

Objective To investigate the effects of varying pulse intervals in the programmed intermittent epidural bolus （PIEB） mode on labor analgesia in primiparous and multiparous women， and to evaluate the differences in analgesic outcomes between these two groups. Methods A total of 60 primiparous and 60 multiparous women who met the inclusion criteria were recruited and randomly allocated into two groups： a 45?minute pulse interval group （P45 group， n = 30） and a 60?minute pulse interval group （P60 group， n = 30）. Epidural labor analgesia was initiated when cervical dilation reached 1 ~ 3 cm. The programmed intermittent epidural bolus （PIEB） mode was started 45 minutes after analgesia commencement in the P45 group and 60 minutes after analgesia commencement in the P60 group. Each pulse delivered 10 ml of a solution containing 0.08% ropivacaine and 0.5 μg/ml sufentanil. Pain scores were assessed using the Visual Analog Scale （VAS） at five specific time points： baseline （t0）， 1 hour post?analgesia initiation （t1）， 2 hours post?analgesia initiation （t2）， full cervical dilation （t3）， and delivery （t4）. Secondary outcomes included Bromage scores， the number of patient?controlled analgesia （PCA） button presses， total drug consumption， and adverse reactions. Results In primiparous women， the VAS score at t1 was significantly lower in the P45 group compared to the P60 group （P < 0.05）， whereas no significant differences were observed in VAS scores between the two groups at t2—t4. The median PCA press count was also significantly lower in the P45 group than in the P60 group （P < 0.05）. However， there were no significant differences between the groups in terms of total drug consumption， Bromage scores， or the incidence of adverse events （P > 0.05）. In multiparous women， no significant differences were found in VAS scores， Bromage scores， or PCA press counts between the P45 and P60 groups at any time point （P > 0.05）. Conversely， total drug consumption was significantly higher in the P45 group compared to the P60 group （P < 0.05）. Conclusions For primiparous women， a 45?minute pulse interval in the PIEB mode not only provides superior labor analgesia but also significantly reduces the frequency of PCA presses without escalating the risk or severity of motor block or adverse events. For multiparous women， the pulse interval does not substantially influence the effectiveness of labor analgesia. These findings contribute valuable new evidence for refining clinical labor analgesia protocols.