Guasch E, Gilsanz F, Díez J, Alsina E
Servicio de Anestesiología, Reanimación y Terapia del Dolor, Hospital Universitario La Paz, Madrid.
Rev Esp Anestesiol Reanim. 2010 May;57(5):267-74. doi: 10.1016/s0034-9356(10)70226-7.
Epidural volume extension (EVE) with saline solution can contribute to greater cephalad spread of drugs injected into the subarachnoid space during cesarean section. We studied the incidence of material hypotension with spinal bupivacaine or levobupivacaine (L-bupivacaine) and the spread after epidural saline injection.
After ethics committee approval, we randomized women scheduled for cesarean section to 4 groups to receive 5 mg of 0.25% bupivacaine with (n=51) or without (n=6) saline EVE; 5 mg of 025% L-bupivacaine (n=50); or 6 mg of 03% L-bupivacaine (n=50). All patients also received 25 microg of fentanyl per 2 mL of local hyperbaric spinal anesthetic. In all except the non-EVE group, 10 mL of saline was infused through an epidural catheter 5 minutes after anesthetic infusion. We recorded patient demographic data, procedural and anesthetic times, incision-clamping times, occurrence of hypotension, ephedrine dose required, motor and sensory blockade, requirement for rescue analgesics, and neonatal outcome.
After 6 patients had been randomized to the non-EVE group, no further patients were assigned because all the women required rescue analgesics. Demographic data, duration of procedure, time between. incision and delivery, and Apgar scores were similar in all the groups. The incidence of hypotension was lower in the group receiving 5 mg of L-bupivacaine (26% vs. 52.9% in the bupivacaine 5-mg group, and 56% in the 6-mg L-bupivacaine group, P = .04). More women given 5 mg of L-bupivacaine required rescue analgesia (46%) than did those receiving 5 mg of bupivacaine (235%) or 6 mg of L-bupivacaine (28%) (P = .039). Hypotension was associated with a lower umbilical cord pH (P = .001). Ephedrine doses over 20 mg were also associated with a lower umbilical cord pH (P = .031).
The incidence of hypotension was lowest in the group anesthetized with 5 mg of L-bupivacaine, but the need for rescue analgesia was greater in this group. Doses of 5 mg and 6 mg may be sufficient for cesarean section, as they provide a good level of sensory blockade.
剖宫产术中向蛛网膜下腔注射药物时，用生理盐水进行硬膜外容积扩展（EVE）有助于药物向头侧更广泛地扩散。我们研究了蛛网膜下腔注射布比卡因或左旋布比卡因（L-布比卡因）后发生低血压的发生率以及硬膜外注射生理盐水后的扩散情况。
经伦理委员会批准后，我们将计划行剖宫产的女性随机分为4组，分别接受含（n = 51）或不含（n = 6）生理盐水EVE的5mg 0.25%布比卡因；5mg 0.25% L-布比卡因（n = 50）；或6mg 0.3% L-布比卡因（n = 50）。所有患者每2mL局部重比重蛛网膜下腔麻醉药中还加入25μg芬太尼。除无EVE组外，在麻醉药注入后5分钟，通过硬膜外导管注入10mL生理盐水。我们记录了患者的人口统计学数据、手术和麻醉时间、切口至钳夹时间、低血压的发生情况、所需麻黄碱剂量、运动和感觉阻滞情况、抢救性镇痛药的需求以及新生儿结局。
在6例患者被随机分入无EVE组后，未再分配患者，因为所有女性均需要抢救性镇痛药。所有组的人口统计学数据、手术持续时间、切口至分娩时间以及阿氏评分相似。接受5mg L-布比卡因组的低血压发生率较低（布比卡因5mg组为26%，而布比卡因5mg组为52.9%，6mg L-布比卡因组为56%，P = 0.04）。接受5mg L-布比卡因的女性中需要抢救性镇痛的比例（46%）高于接受5mg布比卡因（23.5%）或6mg L-布比卡因（28%）的女性（P = 0.039）。低血压与脐动脉血pH值较低相关（P = 0.001）。麻黄碱剂量超过20mg也与脐动脉血pH值较低相关（P = 0.031）。
用5mg L-布比卡因麻醉的组中低血压发生率最低，但该组对抢救性镇痛的需求更大。5mg和6mg的剂量可能足以用于剖宫产，因为它们能提供良好的感觉阻滞水平。
