Novel Oxygenation and Saturation Indices for Mortality Prediction in COVID-19 ARDS Patients: The Impact of Driving Pressure and Mechanical Power.

Background: The oxygenation index (OI) and oxygen saturation index (OSI) are proven mortality predictors in pediatric and adult patients, traditionally using mean airway pressure (P mean ). We introduce novel indices, replacing P mean with DP (ΔP insp ), MP dyn , and MP tot , assessing their potential for predicting COVID-19 acute respiratory distress syndrome (ARDS) mortality, comparing them to traditional indices. Methods: We studied 361 adult COVID-19 ARDS patients for 7 days, collecting ΔP insp , MP dyn , and MP tot , OI-ΔP insp , OI-MP dyn , OI-MP tot , OSI-ΔP insp , OSI-MP dyn , and OSI-MP tot . We compared these in surviving and non-surviving patients over the first 7 intensive care unit (ICU) days using Mann-Whitney U test. Logistic regression receiver operating characteristic (ROC) analysis assessed AUC and CI values for ICU mortality on day three. We determined cut-off values using Youden's method and conducted multivariate Cox regression on parameter limits. Results: All indices showed significant differences between surviving and non-surviving patients on the third day of ICU care. The AUC values of OI-ΔP insp were significantly higher than those of P/F and OI-P mean ( P values .0002 and <.0001, respectively). Similarly, AUC and CI values of OSI-ΔP insp and OSI-MP dyn were significantly higher than those of SpO 2 /FiO 2 and OSI-P mean values (OSI-ΔP insp : P  < .0001, OSI-MP dyn : P values .047 and .028, respectively). OI-ΔP insp , OSI-ΔP insp , OI-MP dyn , OSI-MP dyn , OI-MP tot , and OSI-MP tot had AUC values of 0.72, 0.71, 0.69, 0.68, 0.66, and 0.64, respectively, with cut-off values associated with hazard ratios and P values of 7.06 (HR = 1.84, P  = .002), 8.04 (HR = 2.00, P  ≤ .0001), 7.12 (HR = 1.68, P  = .001), 5.76 (HR = 1.70, P  ≤ .0001), 10.43 (HR = 1.52, P  = .006), and 10.68 (HR = 1.66, P  = .001), respectively. Conclusions: Critical values of all indices were associated to higher ICU mortality rates and extended mechanical ventilation durations. The OI-ΔP insp , OSI-ΔP insp , and OSI-MP dyn indices displayed the strongest predictive capabilities for ICU mortality. These novel indices offer valuable insights for intensivists in the clinical management and decision-making process for ARDS patients.