Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Jongno-Gu, Korea.
Eur J Anaesthesiol. 2011 Jan;28(1):45-50. doi: 10.1097/EJA.0b013e3283408a0f.
Previous studies have failed to demonstrate that the head-down tilt position confers benefits in hypovolaemic hypotensive patients. The aim of this study was to evaluate the haemodynamic effect and vasopressor use by this position in hypotensive patients after the induction of general anaesthesia.
This prospective randomised study involved 98 patients scheduled for elective cardiac surgery and 40 patients (40.1%) developed hypotension after anaesthesia induction. Upon occurrence of hypotension, patients were randomly allocated to the supine (n = 19) or head-down tilt (n = 21) groups (15° head-down tilt position). Blood pressure, heart rate, cardiac index and stroke volume index were recorded at 1-min interval for 10 min from the occurrence of hypotension. Vasopressors were administered to treat hypotension in both groups.
No haemodynamic difference was observed between the supine and head-down tilt groups except for SBP changes from baseline at 1 min (-3.98 ± 6.31 vs. 1.84 ± 8.25%, P = 0.004) and 2 min (1.51 ± 14.34 vs. 9.37 ± 10.57%, P = 0.032). The number of vasopressor administrations and percentage of the patients requiring vasopressors in the supine group were greater than that in the head-down tilt group [median 1 (range 1-5) vs. median 0 (range 0-2), P = 0.002, 19/19 (100%) vs. 10/21 (47.6%), P < 0.001].
The head-down tilt position in hypotensive patients following anaesthesia induction reduced vasopressor requirement by almost one third. Minimal haemodynamic effect may be caused by different vasopressor administrations. This result suggests that the head-down tilt position may enable more stable anaesthesia induction in patients undergoing elective coronary artery bypass graft or valvular heart surgeries.
先前的研究未能表明头低位倾斜在低血容量性低血压患者中有益。本研究旨在评估这种体位在全麻诱导后低血压患者中的血流动力学效应和血管加压药的使用。
这是一项前瞻性随机研究，纳入 98 例行择期心脏手术的患者，其中 40 例（40.1%）在麻醉诱导后发生低血压。发生低血压后，患者随机分为仰卧位（n=19）或头低位倾斜位（n=21）组（头低位倾斜 15°）。从低血压发生后 1 分钟开始，每 1 分钟记录血压、心率、心指数和每搏指数 10 分钟。两组均给予血管加压药治疗低血压。
仰卧位和头低位倾斜组除收缩压从基线变化外（1 分钟时为-3.98±6.31%与 1.84±8.25%，P=0.004；2 分钟时为 1.51±14.34%与 9.37±10.57%，P=0.032），血流动力学无差异。仰卧组血管加压药的使用次数和需要血管加压药的患者百分比均高于头低位倾斜组[中位数 1（范围 1-5）与中位数 0（范围 0-2），P=0.002，19/19（100%）与 10/21（47.6%），P<0.001]。
麻醉诱导后低血压患者的头低位倾斜可使血管加压药需求减少近三分之一。可能是由于血管加压药的使用不同，导致血流动力学变化较小。这一结果表明，头低位倾斜可能使择期冠状动脉旁路移植术或心脏瓣膜手术患者的麻醉诱导更稳定。
