Vadi Sonali Mr, Sanwalka Neha, Suthar Durga
Department of Intensive Care Medicine, Kokilaben Dhirubhai Ambani Hospital and Medical Research Institute, Mumbai, Maharashtra, India.
Department of Nutrition and Biostatistics, NutriCanvas, Mumbai, Maharashtra, India.
Indian J Crit Care Med. 2024 Oct;28(10):917-922. doi: 10.5005/jp-journals-10071-24808. Epub 2024 Sep 30.
The classification of Berlin definition is based on the PaO/FiO ratio, which has been found to have a poor association with mortality. Airway pressures reflect lung compliance and the settings of mechanical ventilators. In this study, we aimed to investigate the change in the severity of COVID-19-associated acute respiratory distress syndrome (ARDS) classification using [PaO/FiO × PEEP] (P/FP) ratio compared to the traditional P/F ratio, and whether the P/FP ratio improves the predictive validity of in-hospital mortality.
Our study sample included patients from the OXIVA-CARDS study. In this secondary analysis, we examined the oxygenation index and oxygen saturation index in relation to the P/FP ratio, as well as the risk of P/FP in mortality. We used Pearson's correlation to assess the relationships between various parameters. Receiver operating characteristic analysis with Youden's index was used to compare the prognostic value of the oxygenation index (OI), oxygen saturation index (OSI), P/F ratio, P/FP ratio, and SaO/FiO ratio for predicting overall mortality. Multiple logistic regression was also performed to determine the impact of mean airway pressure (Pmean), S/F ratio, OI, and P/FP ratio on mortality.
A total of 201 patients (with 1543 measurements) were included in the analysis. Overall, 522 (34%) were reclassified into either more or less severe categories. Patients who were classified as having severe ARDS based on the P/FP ratio had significantly lower P/FP ratio, oxygenation index, and A-a O2 gradient as compared to those classified as having severe ARDS based on the P/F ratio ( < 0.05) at all levels of ARDS severity. On multivariate regression analysis, only the OI significantly impacted mortality ( < 0.05).
We observed that the oxygen index and oxygen saturation index were more sensitive than the PaOFiO ratio and P/FP ratio. Additionally, only the oxygenation index had a significant impact on mortality. By including airway pressures in the calculation of the OI, its predictive ability is enhanced compared to using the S/F ratio, P/F ratio, or P/FP ratio.
The sensitivity of mortality by including Pmean is higher as compared to when only PEEP is taken into consideration. P/FP is a weak predictor of mortality as compared to OI and OSI.
Vadi SMR, Sanwalka N, Suthar D. Oxygenation Index, Oxygen Saturation Index vs PaO/FiO *PEEP: A Secondary Analysis of OXIVA-CARDS Study. Indian J Crit Care Med 2024;28(10):917-922.
柏林定义的分类基于动脉血氧分压与吸入氧浓度比值（PaO/FiO），但该比值与死亡率的关联性较差。气道压力反映肺顺应性和机械通气设置。在本研究中，我们旨在探讨与传统的P/F比值相比，使用[PaO/FiO×呼气末正压（PEEP）]（P/FP）比值时，新型冠状病毒肺炎相关急性呼吸窘迫综合征（ARDS）分类严重程度的变化，以及P/FP比值是否能提高院内死亡率的预测效度。
我们的研究样本包括来自OXIVA-CARDS研究的患者。在这项二次分析中，我们研究了与P/FP比值相关的氧合指数和氧饱和度指数，以及P/FP比值在死亡率方面的风险。我们使用Pearson相关性分析来评估各种参数之间的关系。采用受试者工作特征分析及约登指数来比较氧合指数（OI）、氧饱和度指数（OSI）、P/F比值、P/FP比值和动脉血氧饱和度与吸入氧浓度比值（SaO/FiO）对预测总体死亡率的预后价值。还进行了多因素逻辑回归分析，以确定平均气道压（Pmean）、S/F比值、OI和P/FP比值对死亡率的影响。
共有201例患者（1543次测量）纳入分析。总体而言，522例（34%）被重新分类为更严重或不太严重的类别。与基于P/F比值被分类为重度ARDS的患者相比，基于P/FP比值被分类为重度ARDS的患者在所有ARDS严重程度水平下的P/FP比值、氧合指数和肺泡 - 动脉血氧分压差均显著更低（P<0.05）。在多变量回归分析中，只有OI对死亡率有显著影响（P<0.05）。
我们观察到氧指数和氧饱和度指数比PaO/FiO比值和P/FP比值更敏感。此外，只有氧合指数对死亡率有显著影响。通过在OI计算中纳入气道压力，与使用S/F比值、P/F比值或P/FP比值相比，其预测能力得到增强。
与仅考虑PEEP时相比，纳入Pmean时死亡率的敏感性更高。与OI和OSI相比，P/FP是死亡率的弱预测指标。
Vadi SMR, Sanwalka N, Suthar D. Oxygenation Index, Oxygen Saturation Index vs PaO/FiO *PEEP: A Secondary Analysis of OXIVA-CARDS Study. Indian J Crit Care Med 2024;28(10):917-922.
