Miyabe M, Sato S
Department of Anesthesiology, Institute of Clinical Medicine, University of Tsukuba, Japan.
Reg Anesth. 1997 May-Jun;22(3):239-42. doi: 10.1016/s1098-7339(06)80008-8.
The effect of the head-down tilt position after induction of spinal anesthesia for cesarean delivery on blood pressure and level of sensory block was examined.
Patients were allocated randomly into two groups, the head-down tilt group (n = 17) and the horizontal group (n = 17). In the head-down tilt group, patients were positioned with a 10 degrees head-down tilt immediately after supine positioning, while those in the horizontal group were maintained in a horizontal position. All patients received 500 mL of lactated Ringer's solution intravenously over 10 minutes prior to spinal injection, a wedge was placed under the patient's right hip, and the operating table was rotated 5 degrees in a counterclockwise direction to provide left uterine displacement. Hypotension (defined as systolic blood pressure below 100 mm Hg) was treated with 5 mg ephedrine intravenously and an increase in the infusion rate of lactated Ringer's solution. The change in systolic blood pressure was expressed as percent change from the baseline value.
Systolic blood pressure decreased 20% at 3 minutes after spinal block in both groups but recovered to half of this decrease. The incidence of postspinal hypotension was not different between the two groups. The total amount of ephedrine and lactated Ringer's solution administered during the first 20 minutes of spinal block did not differ between the two groups nor did the extent of the cephalad spread of analgesia 20 minutes after spinal block (T4 +/- 2 vs T4 +/- 1 for the head-down and horizontal groups, respectively).
The head-down position is concluded to have no effect on the incidence of hypotension during spinal anesthesia for cesarean delivery.
研究剖宫产术脊髓麻醉诱导后头低倾斜位对血压及感觉阻滞平面的影响。
将患者随机分为两组，头低倾斜组（n = 17）和水平组（n = 17）。头低倾斜组患者在仰卧位定位后立即采用头低10度倾斜位，而水平组患者保持水平位。所有患者在脊髓注射前10分钟内静脉输注500 mL乳酸林格液，在患者右髋下放置一个楔形垫，并将手术台逆时针旋转5度以实现子宫左移。低血压（定义为收缩压低于100 mmHg）采用静脉注射5 mg麻黄碱及增加乳酸林格液输注速率进行治疗。收缩压变化以相对于基线值的百分比变化表示。
两组患者在脊髓阻滞3分钟时收缩压均下降20%，但恢复至下降幅度的一半。两组脊髓后低血压的发生率无差异。脊髓阻滞前20分钟内麻黄碱和乳酸林格液的给药总量在两组间无差异，脊髓阻滞后20分钟镇痛向头端扩散的程度（头低倾斜组和水平组分别为T4±2和T4±1）也无差异。
得出头低体位对剖宫产术脊髓麻醉期间低血压的发生率无影响的结论。
