背景:最近的研究调查了躯干倾斜对机械通气ARDS患者呼吸力学的影响,报道了分区呼吸力学的姿势差异。与更直立的姿势相比,平卧位提供了下肺和胸壁弹性,允许降低驱动压力和吸气端肺压。然而,躯干倾斜对肥胖ARDS患者呼吸力学的影响尚不确定。
目的:肥胖和非肥胖ARDS患者体位变化对分区呼吸力学的影响是否不同?
方法:在这项单中心研究中,患有ARDS的肥胖和非肥胖患者被随机分为两个15分钟的步骤,其中躯干倾斜度从半卧位(头向上40°)变为仰卧位(0°),反之亦然。在每个步骤的最后,划分呼吸力学,测量气道开放压和动脉血气。配对t检验用于检查每组的呼吸力学和血气变量。
结果:纳入40例连续患者。20人肥胖(BMI38.4(34.5-42.3)kg/m2),20人非肥胖(BMI26.6(25.2-28.5)kg/m2)。在肥胖患者中,肺和胸壁弹性,驱动压力,吸气经肺压,PaCO2和通气比仰卧低于半卧位(P<0.001)。仰卧时气道阻力更大(P=0.006)。在非肥胖患者中,仅仰卧位的胸壁弹性较低(P<0.001)。
结论:在机械通气的肥胖ARDS患者中,仰卧位提供了下肺和胸壁弹性,更好的二氧化碳清除,比半躺着的姿势。
背景:本研究在澳大利亚新西兰临床试验注册中心(ACTRN12623000794606)注册。
BACKGROUND: Studies investigating the effect of trunk inclination on respiratory mechanics in mechanically ventilated patients with ARDS have reported postural differences in partition respiratory mechanics. Compared with more upright positions, the supine-flat position provided lower lung and chest wall elastance, allowing reduced driving pressures and end-inspiratory transpulmonary pressure. However, the effect of trunk inclination on respiratory mechanics in patients with obesity and ARDS is uncertain.
OBJECTIVE: Does the effect of change in posture on partition respiratory mechanics differ between patients with ARDS with and without obesity?
METHODS: In this single-center study, patients with ARDS with and without obesity were randomized into two 15-minute steps in which trunk inclination was changed from semi-recumbent (40° head up) to supine-flat (0°), or vice versa. At the end of each step partition respiratory mechanics, airway opening pressure and arterial blood gases were measured. Paired t test was used to examine respiratory mechanics and blood gas variables in each group.
RESULTS: Forty consecutive patients were enrolled. Twenty were obese (BMI, 38.4 [34.5-42.3]), and 20 were non-obese (BMI, 26.6 [25.2-28.5]). In the patients with obesity, lung and chest wall elastance, driving pressure, inspiratory transpulmonary pressure, Paco2, and ventilatory ratio were lower supine than semi-recumbent (P < .001). Airways resistance was greater supine (P = .006). In the patients without obesity, only chest wall elastance was lower in supine vs semi-recumbent (P < .001).
CONCLUSIONS: In mechanically ventilated patients with ARDS and obesity, supine posture provided lower lung and chest wall elastance, and better CO2 clearance, than the semi-recumbent posture.
BACKGROUND: This study was registered with Australian New Zealand Clinical Trials Registry (ACTRN12623000794606).