硬膜外麻醉对七氟烷与舒芬太尼麻醉婴儿的经食管多普勒超声及血液动力学的影响

背景一般认为小儿硬膜外麻醉（EA）时血液动力学稳定，但与成人相比，硬膜外麻醉对婴儿心排出量（cO）的血液动力学影响研究较少。方法本研究使用经食管多普勒监测CO，前瞻性地研究了14例拟行腹部外科手术、体重小于10埏的婴儿。在七氟烷全身麻醉期间，用0．25％布比卡因和1：200000肾上腺素的复合液以0．75ml／kg给予腰部EA，麻醉前后用经食管多普勒监测CO。分别在施行硬膜外麻醉前、麻醉后5、15和20分钟测量CO、动脉血压和心率。结果七氟烷和舒芬太尼麻醉患儿接受EA后心脏每搏量增加29％（P〈0．0001），心率降低13％（P〈0．0001）。同时EA使收缩期动脉压、舒张期动脉压、平均动脉压和全身血管阻力分别明显降低11％、18％、15％和25％。相反，CO保持不变。结论观察到的每搏量增加可能是由于EA 引起的交感神经阻滞使后负荷最佳化的结果。本研究证实体重小于10kg的婴儿实施EA时血液动力学稳定，此结果支持队在小儿群体中的应用。

BACKGROUND： It is thought that pediatric epidural anesthesia （EA） provides hemodynamic stability in children. However, when compared with information relating to adults, tittle is known about the hemodynamic effects of epidural EA on cardiac output （CO） in infants. METHODS： Using transesophageal Doppler to monitor CO, we prospectively studied 14 infants 〈 10 kg who were scheduled for abdominal surgery. During sevoflurane general anesthesia, CO transesophageal Doppler monitoring was performed before and after lumbar EA with 0.75 ml/kg of 0. 25% bupivacaine and i ： 200 000 adrenaline. CO, arterial blood pressure, and heart rate were measured before and 5, 15, and 20 min after performance of EA. RESULTS： In patients anesthetized with sevoflurane and sufentanil, EA resulted in an increase in stroke volume by 29% （P 〈 0. 0001 ） and a decrease in heart rate by 13% （P 〈 0. 0001 ）. EA also induced a significant decrease in systolic, diastolic, mean arterial blood pressure, and systemic vascular resistance by 11%, 18%, 15 %, and 25 %, respectively. Conversely, CO remained unchanged. CONCLUSIONS： The increase in stroke volume observed is probably explained by optimization of afterload because of the sympathetic blockade induced by EA. These results confirm that EA provides hemodynamic stability in infants weighing 〈 10 kg and supports the use of EA in this pediatric population.