Department of Obstetrics and Gynaecology and Department of Pharmacology, The University of Melbourne, Parkville, Vic., Australia.
Department of Anaesthesia, The Royal Women's Hospital, Parkville, Vic., Australia.
Anaesthesia. 2018 Nov;73(11):1345-1352. doi: 10.1111/anae.14418. Epub 2018 Aug 31.
Optimal positioning for anaesthesia in pregnant women involves balancing the need for ideal tracheal intubation conditions (achieved by the head elevated ramped position), with the prevention of reduced cardiac output from aortocaval compression (achieved by left lateral pelvic tilt). No studies have examined the effect on cardiac output of left lateral pelvic tilt in the ramped position. We studied non-labouring, non-anaesthetised healthy term pregnant women who underwent baseline (left lateral decubitus) cardiac assessment using transthoracic echocardiography. We then compared cardiac output, maternal physiological variables, fetal heart rate and comfort scores in three positions: left lateral decubitus; ramped position with wedge; and ramped position alone. Thirty women completed the study. Mean (SD) age, gestation and body mass index were 33.5 (3.93) years, 38.5 (0.94) weeks and 29.0 (4.0) kg.m , respectively. Mean ejection fraction, left ventricular internal diameter and mitral valve E/e' were 55.2 (6.8) %, 4.70 (0.43) cm and 7.50 (1.82), respectively. There were no differences in cardiac output between the positions (p = 0.503). There were no differences in systolic (p = 0.955) or diastolic (p = 0.987) blood pressure, maternal heart rate (p = 0.133), oxygen saturation, respiratory rate (p = 0.964) or fetal heart rate (p = 0.361) between ramped with wedge and ramped alone positions. Left lateral decubitus was most comfortable (p = 0.001), however, there were no differences in comfort levels between ramped with wedge and ramped alone positions. The ramped position without left lateral tilt is safe and acceptable in non-labouring, non-anaesthetised, healthy term pregnant women. Left lateral pelvic tilt may be unnecessary in the head elevated ramped position in term pregnant women.
孕妇麻醉的最佳体位需要平衡理想的气管插管条件（头高位斜坡位可实现）与防止腹主动脉受压导致的心输出量降低（左侧侧卧位骨盆倾斜可实现）。目前尚无研究评估头高位斜坡位时左侧侧卧位骨盆倾斜对心输出量的影响。我们研究了非临产、非麻醉的健康足月孕妇，使用经胸超声心动图在左侧卧位进行基线（左侧卧位）心功能评估。然后比较了三种体位下的心输出量、产妇生理参数、胎儿心率和舒适度评分：左侧卧位、斜坡位加楔形垫、单纯斜坡位。30 名妇女完成了这项研究。平均（标准差）年龄、孕周和体重指数分别为 33.5（3.93）岁、38.5（0.94）周和 29.0（4.0）kg.m。平均射血分数、左心室内径和二尖瓣 E/e'分别为 55.2（6.8）%、4.70（0.43）cm 和 7.50（1.82）。三种体位的心输出量无差异（p=0.503）。收缩压（p=0.955）或舒张压（p=0.987）、产妇心率（p=0.133）、血氧饱和度、呼吸频率（p=0.964）或胎儿心率（p=0.361）在斜坡位加楔形垫与单纯斜坡位之间均无差异。左侧卧位最舒适（p=0.001），但斜坡位加楔形垫与单纯斜坡位之间的舒适度评分无差异。非临产、非麻醉的健康足月孕妇，头高位无左侧倾斜斜坡位是安全且可接受的。在足月孕妇头高位斜坡位时，左侧骨盆倾斜可能不是必需的。
