Pediatric ARDS phenotypes in critical COVID-19: implications for therapies and outcomes.

Purposeto describe lung mechanics in Pediatric Acute Respiratory Disease Syndrome (PARDS) associated with COVID-19. We hypothesize two phenotypes according to respiratory system mechanics and clinical diagnosis. Methodsa concurrent multicenter observational study was performed, analyzing clinical variables and pulmonary mechanics of PARDS associated with COVID-19 in 4 Pediatric intensive care units (PICUs) of Peru. Subgroup analysis included PARDS associated with multisystem inflammatory syndrome in children (MIS-C), MIS-PARDS, and PARDS with COVID-19 primary respiratory infection, C-PARDS. In addition, receiver operator curve analysis (ROC) for mortality was performed. Results30 patients were included. Age was 7.5(4-11) years, 60% male, and mortality 23%. 47% corresponded to MIS-PARDS and 53% to C-PARDS phenotypes. C-PARDS had positive RT-PCR in 67% and MIS-PARDS none (p<0.001). C-PARDS group had more profound hypoxemia (P/Fratio<100, 86%vs38%,p<0.01) and higher driving-pressure (DP) [14(10-22)vs10(10-12)cmH2O], and lower compliance of the respiratory system (CRS)[0.5(0.3-0.6)vs 0.7(0.6-0.8)ml/kg/cmH2O] compared to MIS-PARDS (all p<0.05). ROC-analysis for mortality showed that DP had the best performance [AUC 0.91(95%CI0.81-1.00), with the best cut-point of 15 cmH2O (100% sensitivity and 87% of specificity). Mortality in C-PARDS was 38% and 7% in MIS-PARDS(p=0.09). MV free-days were 12(0-23) in C-PARDS and 23(21-25) in MIS-PARDS(p=0.02) Conclusioncritical pediatric COVID-19 is heterogeneous in children. COVID-19 PARDS had two phenotypes with distinctive pulmonary mechanics features. Characteristics of C-PARDS are like a classic primary PARDS, while a decoupling between compliance and hypoxemia was more frequent in MIS-PARDS. In addition, C-PARDS had fewer MV free-days. DP [&ge;] 15 cmH2O had the best performance of the quasi-static calculations to discriminate for mortality. Standardized pulmonary mechanics measurements in PARDS might reveal essential information to tailor the ventilatory strategy in pediatric critical COVID-19. Take-home messageO_LIPARDS associated with COVID-19 have two different phenotypes based on clinical diagnosis and pulmonary mechanics. C_LIO_LIC-PARDS group was characterized as a classic moderate to severe primary ARDS. A decoupling between compliance and hypoxemia was more frequent in MIS-PARDS. Regarding outcomes, C-PARDS had less VFD and a trend toward higher mortality. C_LIO_LIData from the quasi-static calculations were associated with mortality; DP[&ge;] 15 cmH2O was the best discriminator. C_LIO_LIStandardized pulmonary mechanics measurements in PARDS might reveal essential information to tailor the ventilatory strategy, characterizing different phenotypes and parameters associated with outcomes. C_LI TweetLung mechanics help to differentiate two different phenotypes in PARDS associated with COVID-19. C-PARDS associated with respiratory infection, and MIS-PARDS, associated with MIS-C. Also, lung mechanics variables were associated with mortality, being DP [&ge;] 15 cmH2O the best discriminator.