Which spontaneous breathing trial should be used to reproduce post-extubation respiratory effort in COVID-19-related ARDS? A multicenter randomized crossover study.

BACKGROUND: Spontaneous breathing trials (SBT) guide extubation decisions in intensive care unit (ICU), predicting the respiratory effort required by the patient after extubation. Different SBTs exist and should be adapted to critical illness. Viral pneumonias such as COVID-19 combine lung injury, sepsis-induced systemic inflammation, and encephalopathy, making classification challenging. The objective was to assess which SBT could be used to reproduce postextubation respiratory effort in COVID-19-related acute respiratory distress syndrome (ARDS) patients. METHODS: In this multicenter randomized crossover study, COVID-19-related ARDS patients mechanically ventilated at least 24 hours and ready for extubation underwent 3 different 15-minute SBT at random order: pressure support ventilation of 7-cmH2O with positive end-expiratory pressure (PEEP) of 0-cmH2O (PSV7PEEP0), PSV 0-cmH2O with PEEP 0-cmH2O (PSV0PEEP0) and T-piece trial. At baseline, end of each SBT, and 20 minutes after extubation, surrogates of respiratory effort were measured: esophageal pressure-time-product (PTPes), PTPes per minute (PTPes.min), swing esophageal pressure (SwingPes), and SwingPes per minute (SwingPes.min). RESULTS: Sixty measurements of respiratory effort from 12 patients were analyzed. Median PTPes.min increased from 193.8 [170.8-227.2] cmH2O.s/min at baseline to 236.6 [192.1-313.6] after extubation, with no significant differences between SBTs and postextubation. SwingPes and SwingPes.min were lower during PSV7-PEEP0 than after extubation, with median paired differences of 4.7 (95% CI 0.6-9.8) and 115.3 (95% CI 4.8-297.8), but these differences did not remain significant after correction for multiple comparisons. CONCLUSION: No SBT modality differed significantly from post-extubation respiratory effort, suggesting that none could be excluded in COVID-19-related ARDS patients.