Ramanathan S, Desai N S, Zakowski M
Department of Anesthesiology, New York University Medical Center, New York, USA.
Reg Anesth. 1995 May-Jun;20(3):199-205.
To assess the systemic vascular uptake of epinephrine from the lumbar epidural space in parturients during epidural anesthesia for cesarean delivery.
Thirty-eight healthy patients were randomly divided into two equal groups. In one group, bupivacaine-epinephrine (5 micrograms/mL) mixture was used to produce lumbar epidural anesthesia to a T6 level; in the other group, bupivacaine 0.5%. Maternal venous plasma epinephrine and norepinephrine concentrations were measured before anesthesia (baseline), at a T6 sensory level and at delivery; and 10, 20, 30, and 50 minutes after delivery. Statistical comparisons were made using nonparametric analysis of variance at P < .05.
In the bupivacaine-epinephrine group, the plasma epinephrine concentration increased approximately fourfold at T6 sensory level compared to the baseline value or to the corresponding value in the bupivacaine group (P < .01), and it remained elevated significantly for 20 minutes after delivery. In the bupivacaine group, no significant changes occurred in the epinephrine concentrations. In both groups, plasma norepinephrine concentration increased at T6 level approximately 1.8-fold compared to the baseline value (P < .01), with no intergroup differences.
Epinephrine is absorbed from the epidural space and raises the maternal circulating epinephrine concentration. Maternal plasma norepinephrine concentration rises during lumbar epidural anesthesia regardless of epinephrine use.
评估剖宫产硬膜外麻醉期间产妇腰段硬膜外间隙肾上腺素的全身血管摄取情况。
38例健康患者随机分为两组，每组人数相等。一组使用布比卡因 - 肾上腺素（5微克/毫升）混合液产生T6平面的腰段硬膜外麻醉；另一组使用0.5%布比卡因。在麻醉前（基线）、T6感觉平面时、分娩时以及分娩后10、20、30和50分钟测量产妇静脉血浆中肾上腺素和去甲肾上腺素的浓度。采用非参数方差分析进行统计学比较，P < 0.05为有统计学差异。
在布比卡因 - 肾上腺素组，与基线值或布比卡因组的相应值相比，T6感觉平面时血浆肾上腺素浓度增加约四倍（P < 0.01），且分娩后20分钟内仍显著升高。在布比卡因组，肾上腺素浓度无显著变化。两组中，T6平面时血浆去甲肾上腺素浓度与基线值相比增加约1.8倍（P < 0.01），组间无差异。
肾上腺素可从硬膜外间隙吸收并升高产妇循环中的肾上腺素浓度。无论是否使用肾上腺素，腰段硬膜外麻醉期间产妇血浆去甲肾上腺素浓度都会升高。
