Larner College of Medicine, University of Vermont, Burlington, Vermont, United States.
Department of Anesthesiology, University of Vermont Medical Center, Burlington, Vermont, United States.
J Appl Physiol (1985). 2023 Jun 1;134(6):1390-1402. doi: 10.1152/japplphysiol.00551.2022. Epub 2023 Apr 6.
Mechanical power can describe the complex interaction between the respiratory system and the ventilator and may predict lung injury or pulmonary complications, but the power associated with injury of healthy human lungs is unknown. Body habitus and surgical conditions may alter mechanical power but the effects have not been measured. In a secondary analysis of an observational study of obesity and lung mechanics during robotic laparoscopic surgery, we comprehensively quantified the static elastic, dynamic elastic, and resistive energies comprising mechanical power of ventilation. We stratified by body mass index (BMI) and examined power at four surgical stages: level after intubation, with pneumoperitoneum, in Trendelenburg, and level after releasing the pneumoperitoneum. Esophageal manometry was used to estimate transpulmonary pressures. Mechanical power of ventilation and its bioenergetic components increased over BMI categories. Respiratory system and lung power were nearly doubled in subjects with class 3 obesity compared with lean at all stages. Power dissipated into the respiratory system was increased with class 2 or 3 obesity compared with lean. Increased power of ventilation was associated with decreasing transpulmonary pressures. Body habitus is a prime determinant of increased intraoperative mechanical power. Obesity and surgical conditions increase the energies dissipated into the respiratory system during ventilation. The observed elevations in power may be related to tidal recruitment or atelectasis, and point to specific energetic features of mechanical ventilation of patients with obesity that may be controlled with individualized ventilator settings. Mechanical power describes the complex interaction between a patient's lungs and the ventilator and may be useful in predicting lung injury. However, its behavior in obesity and during dynamic surgical conditions is not understood. We comprehensively quantified ventilation bioenergetics and effects of body habitus and common surgical conditions. These data show body habitus is a prime determinant of intraoperative mechanical power and provide quantitative context for future translation toward a useful perioperative prognostic measurement.
机械功率可以描述呼吸系统与呼吸机之间的复杂相互作用，并可能预测肺损伤或肺部并发症，但健康人肺部损伤相关的功率尚不清楚。体型和手术条件可能会改变机械功率，但尚未进行测量。在一项关于肥胖症和机器人腹腔镜手术期间肺力学的观察性研究的二次分析中，我们全面量化了通气机械功率的静态弹性、动态弹性和阻力能量。我们按体重指数（BMI）分层，并检查了四个手术阶段的功率：插管后水平、气腹后水平、Trendelenburg 体位后水平和释放气腹后水平。食管测压法用于估计跨肺压。通气机械功率及其生物能量成分随 BMI 类别增加。与瘦者相比，3 级肥胖者的呼吸系统和肺功能几乎增加了一倍，在所有阶段均如此。与瘦者相比，2 级或 3 级肥胖者的呼吸系功率消耗增加。通气机械功率增加与跨肺压降低相关。体型是增加术中机械功率的主要决定因素。肥胖和手术条件增加了通气时耗散到呼吸系统的能量。观察到的功率升高可能与潮气量募集或肺不张有关，并指向肥胖患者机械通气的特定能量特征，这些特征可能可以通过个体化的呼吸机设置进行控制。机械功率描述了患者肺部与呼吸机之间的复杂相互作用，并且可能有助于预测肺损伤。然而，它在肥胖症和动态手术条件下的行为尚不清楚。我们全面量化了通气生物能量学以及体型和常见手术条件的影响。这些数据表明，体型是术中机械功率的主要决定因素，并为未来向有用的围手术期预后测量转化提供了定量背景。
