Morales-Quinteros Luis, Schultz Marcus J, Bringué Josep, Calfee Carolyn S, Camprubí Marta, Cremer Olaf L, Horn Janneke, van der Poll Tom, Sinha Pratik, Artigas Antonio, Bos Lieuwe D
Intensive Care Unit, Hospital Universitari Sagrat Cor, Grupo Quironsalud, Carrer de Viladomat, 288, 08029, Barcelona, Spain.
Department of Intensive Care, Academic Medical Center, Amsterdam, The Netherlands.
Ann Intensive Care. 2019 Nov 21;9(1):128. doi: 10.1186/s13613-019-0601-0.
Indirect indices for measuring impaired ventilation, such as the estimated dead space fraction and the ventilatory ratio, have been shown to be independently associated with an increased risk of mortality. This study aimed to compare various methods for dead space estimation and the ventilatory ratio in patients with acute respiratory distress syndrome (ARDS) and to determine their independent values for predicting death at day 30. The present study is a post hoc analysis of a prospective observational cohort study of ICUs of two tertiary care hospitals in the Netherlands.
Individual patient data from 940 ARDS patients were analyzed. Estimated dead space fraction and the ventilatory ratio at days 1 and 2 were significantly higher among non-survivors (p < 0.01). Dead space fraction calculation using the estimate from physiological variables [V/V] and the ventilatory ratio at day 2 showed independent association with mortality at 30 days (odds ratio 1.28 [95% CI 1.02-1.61], p < 0.03 and 1.20 [95% CI, 1.01-1.40], p < 0.03, respectively); whereas, the Harris-Benedict [V/V] and Penn State [V/V] estimations were not associated with mortality. The predicted validity of the estimated dead space fraction and the ventilatory ratio improved the baseline model based on PEEP, PaO/FiO, driving pressure and compliance of the respiratory system at day 2 (AUROCC 0.72 vs. 0.69, p < 0.05).
Estimated methods for dead space calculation and the ventilatory ratio during the early course of ARDS are associated with mortality at day 30 and add statistically significant but limited improvement in the predictive accuracy to indices of oxygenation and respiratory system mechanics at the second day of mechanical ventilation.
用于测量通气功能受损的间接指标，如估计的死腔分数和通气比，已被证明与死亡率增加独立相关。本研究旨在比较急性呼吸窘迫综合征（ARDS）患者死腔估计和通气比的各种方法，并确定它们在预测第30天死亡方面的独立价值。本研究是对荷兰两家三级护理医院重症监护病房的一项前瞻性观察队列研究的事后分析。
分析了940例ARDS患者的个体患者数据。非幸存者在第1天和第2天的估计死腔分数和通气比显著更高（p<0.01）。使用生理变量估计值[V/V]计算的死腔分数和第2天的通气比与30天死亡率独立相关（优势比分别为1.28[95%CI 1.02 - 1.61]，p<0.03和1.20[95%CI，1.01 - 1.40]，p<0.03）；而Harris - Benedict[V/V]和宾夕法尼亚州立大学[V/V]估计值与死亡率无关。估计的死腔分数和通气比的预测有效性改善了基于第2天呼气末正压、动脉血氧分压/吸入氧分数值、驱动压力和呼吸系统顺应性的基线模型（曲线下面积0.72对0.69，p<0.05）。
ARDS病程早期死腔计算和通气比的估计方法与第30天死亡率相关，并且在机械通气第二天对氧合和呼吸系统力学指标的预测准确性有统计学上显著但有限的提高。
