Le Coq G, Ducot B, Benhamou D
Department of Anesthesia, Hôpital Antoine-Béclère, Clamart, France.
Can J Anaesth. 1998 Aug;45(8):719-23. doi: 10.1007/BF03012140.
To determine the causes of failure of epidural analgesia during labour and delivery.
During six months, pregnant patients receiving epidural analgesia and delivering vaginally were studied prospectively. Bupivacaine 0.125% was used for the initial bolus dose and subsequent continuous infusion. Top-ups of the same solution were used for inadequate pain relief assessed using a visual analogue pain score (VAPS) and/or by clinical examination. Inadequate pain relief was defined as the need for > or = 2 top-ups in addition to epidural infusion and failure during delivery as VAPS > or = 30 mm during the expulsion phase.
1009 patients delivered during this period, 596 had epidural analgesia for vaginal delivery of a live infant and data were complete in 456. Inadequate pain relief during labour and during delivery were found in 5.3% and 19.7% of patients. Risk factors of inadequate pain relief included: inadequate analgesic efficacy of the first dose (Odds ratio: 3.5, P = 0.001) and posterior presentation (Odds ratio: 5.6, P = 0.001). Radicular pain during epidural placement was associated with failure during labour (Odds ratio: 3.9, P = 0.05). Duration of epidural analgesia > six hours (Odds ratio: 9.1, P = 0.001) was a risk factor for insufficient pain relief during labour whereas duration of epidural analgesia < one hour was associated with pain during delivery (Odds ratio: 18.3, P = 0.001).
Several obstetrical and epidural-related factors increase the risk of inadequate epidural analgesia. For some, simple changes of practice pattern may lead to improved pain relief.
确定分娩期间硬膜外镇痛失败的原因。
在六个月期间，对接受硬膜外镇痛并经阴道分娩的孕妇进行前瞻性研究。初始推注剂量及随后的持续输注均使用0.125%的布比卡因。使用视觉模拟疼痛评分（VAPS）和/或临床检查评估疼痛缓解不足时，使用相同溶液进行追加剂量。疼痛缓解不足定义为除硬膜外输注外还需要≥2次追加剂量，分娩期间失败定义为分娩期VAPS≥30 mm。
在此期间有1009例患者分娩，596例接受硬膜外镇痛以经阴道分娩活婴，456例数据完整。分娩期间和分娩时疼痛缓解不足的患者分别占5.3%和19.7%。疼痛缓解不足的风险因素包括：首剂镇痛效果不佳（比值比：3.5，P = 0.001）和枕后位（比值比：5.6，P = 0.001）。硬膜外置管期间的根性疼痛与分娩期间失败相关（比值比：3.9，P = 0.05）。硬膜外镇痛持续时间>6小时（比值比：9.1，P = 0.001）是分娩期间疼痛缓解不足的风险因素，而硬膜外镇痛持续时间<1小时与分娩时疼痛相关（比值比：18.3，P = 0.001）。
若干产科及与硬膜外相关的因素增加了硬膜外镇痛不足的风险。对于某些因素，简单改变操作模式可能会改善疼痛缓解情况。
