ABSTRACT
Background Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus-associated pneumonia and acute respiratory distress syndrome (ARDS) were often associated with hyperinflammation and elevation of several serum inflammatory markers but usually less than what is observed in non-coronavirus disease (COVID) ARDS. Elevated inflammatory markers such as C-reactive protein, interleukin (IL)-6, etc., are associated with severe infection. This study identified subphenotypes of COVID-19 ARDS patients by latent profile analysis in a cohort of Indian patients. Methods Data of n = 233 adult Indian patients with laboratory-confirmed SARS-CoV-2 infection admitted to a tertiary care teaching hospital were analyzed in this retrospective study. Only patients with acute respiratory failure (defined by partial pressure of oxygen/fraction of inspired oxygen ratio < 200 mm Hg) and chest X-ray showing bilateral infiltrates were included. Results The patients' mean (standard deviation) age was 53.3 (14.9) years, and 62% were male. A two subphenotypic model was formulated based on the lowest Bayesian information criterion. Neutrophil-to-lymphocyte ratio and serum IL-6 were latent variables in that model (entropy 0.91). The second phenotype (hyperinflammatory) had lower platelet count ( p = 0.02), higher serum creatinine ( p = 0.004), higher C-reactive protein ( p = 0.001), higher ferritin ( p < 0.001), and serum lactate dehydrogenase ( p = 0.009). Age-adjusted hospital mortality ( p = 0.007), duration of hospital stay ( p < 0.001), and duration of intensive care unit stay ( p < 0.001) were significantly higher in the second subphenotype. Conclusion Two distinct but overlapping subphenotypes were identified in SARS-CoV-2-associated respiratory failure. Hyperinflammatory subphenotype was associated with significantly poor short-term outcomes.
ABSTRACT
BACKGROUND: As respiratory system compliances are heterogenous, we hypothesized that individualized intraoperative positive end-expiratory pressure titration on the basis of lowest driving pressure can reduce postoperative atelectasis and improve intraoperative oxygenation and postoperative lung functions. METHODS: Eighty-two adult patients undergoing major abdominal surgery were recruited in this randomized trial. In the titrated positive end-expiratory pressure group, positive end-expiratory pressure was titrated incrementally until lowest driving pressure was achieved, and the same procedure was repeated in every 2 hours. In the fixed positive end-expiratory pressure group, a positive end-expiratory pressure of 5 cmH2O was used throughout the surgery. The primary objective of this study was lung ultrasound score noted at the completion of surgery and 5 minutes after extubation at 12 lung areas bilaterally. RESULTS: Mean (standard deviation) age of the recruited patients were 43.8 (17.3) years, and 50% of all patients (41 of 82) were women. Lung ultrasound aeration scores were significantly higher in the fixed positive end-expiratory pressure group both before and after extubation (median [interquartile range] 7 [5-8] vs 4 [2-6] before extubation and 8 [6-9] vs 5 [3-7] after extubation; P = .0004 and P = .0011, respectively). Incidence of postoperative pulmonary complications was significantly lower in the titrated positive end-expiratory pressure group (absolute risk difference [95% CI] 17.1% [32.5%-1.7%]; P = .034). The number of patients requiring postoperative supplemental oxygen therapy to maintain SpO2 >95%, the requirement of intraoperative rescue therapy, and the duration of hospital stay were similar in both of the groups. CONCLUSION: Intraoperative titrated positive end-expiratory pressure reduced postoperative lung atelectasis in adult patients undergoing major abdominal surgery. Further large clinical trials are required to know its effect on postoperative pulmonary complications.
