Influence of mechanical power and its components on mechanical ventilation in SARS-CoV-2

ABSTRACT Objective: To analyze the influence of mechanical power and its components on mechanical ventilation for patients infected with SARS-CoV-2; identify the values of the mechanical ventilation components and verify their correlations with each other and with the mechanical power and effects on the result of the Gattinoni-S and Giosa formulas. Methods: This was an observational, longitudinal, analytical and quantitative study of respirator and mechanical power parameters in patients with SARS-CoV-2. Results: The mean mechanical power was 26.9J/minute (Gattinoni-S) and 30.3 J/minute (Giosa). The driving pressure was 14.4cmH2O, the plateau pressure was 26.5cmH2O, the positive end-expiratory pressure was 12.1cmH2O, the elastance was 40.6cmH2O/L, the tidal volume was 0.36L, and the respiratory rate was 32 breaths/minute. The correlation between the Gattinoni and Giosa formulas was 0.98, with a bias of -3.4J/minute and a difference in the correlation of the resistance pressure of 0.39 (Gattinoni) and 0.24 (Giosa). Among the components, the correlations between elastance and driving pressure (0.88), positive end-expiratory pressure (-0.54) and tidal volume (-0.44) stood out. Conclusion: In the analysis of mechanical ventilation for patients with SARS-CoV-2, it was found that the correlations of its components with mechanical power influenced its high momentary values and and that the correlations of its components with each other influenced their behavior throughout the study period. Because they have specific effects on the Gatinnoni-S and Giosa formulas, the mechanical ventilation components influenced their calculations and caused divergence in the mechanical power values.摘要 目的：分析机械功率及其组成成分对新型冠状病毒（SARS-CoV-2）感染患者机械通气的影响；明确机械通气各参数的实测值，验证各参数间的相关性、参数与机械功率的相关性，以及各参数对Gattinoni-S与Giosa公式计算结果的影响。 方法：本研究为针对新型冠状病毒感染患者的呼吸机参数与机械功率参数的观察性、纵向分析性定量研究。 结果：基于Gattinoni-S公式计算的平均机械功率为26.9J/min，基于Giosa公式则为30.3J/min。驱动压（driving pressure）为14.4cmH₂O，平台压（plateau pressure）为26.5cmH₂O，呼气末正压（positive end-expiratory pressure）为12.1cmH₂O，弹性（elastance）为40.6cmH₂O/L，潮气量（tidal volume）为0.36L，呼吸频率（respiratory rate）为32次/分。Gattinoni与Giosa公式的相关系数为0.98，偏倚为-3.4J/min，阻力压的相关系数差值分别为0.39（Gattinoni组）与0.24（Giosa组）。在各参数间，弹性与驱动压的相关性（0.88）、弹性与呼气末正压的相关性（-0.54）以及弹性与潮气量的相关性（-0.44）最为显著。 结论：针对新型冠状病毒感染患者的机械通气分析显示，机械通气各参数与机械功率的相关性会影响其瞬时高值水平，而各参数间的相关性则会影响研究周期内的参数变化趋势。由于机械通气各参数对Gattinoni-S及Giosa公式存在特异性影响，因此其会对公式计算结果产生干扰，进而导致机械功率测算值出现偏差。