Lung Recruitment, Individualized PEEP, and Prone Position Ventilation for COVID-19-Associated Severe ARDS: A Single Center Observational Study.

Patients with coronavirus disease 2019 (COVID-19) may develop severe acute respiratory distress syndrome (ARDS). The aim of the study was to explore the lung recruitability, individualized positive end-expiratory pressure (PEEP), and prone position in COVID-19-associated severe ARDS. Twenty patients who met the inclusion criteria were studied retrospectively (PaO/FiO 68.0 ± 10.3 mmHg). The patients were ventilated under volume-controlled mode with tidal volume of 6 mL/kg predicted body weight. The lung recruitability was assessed the improvement of PaO, PaCO, and static respiratory system compliance (C) from low to high PEEP (5-15 cmHO). Patients were considered recruitable if two out of three parameters improved. Subsequently, PEEP was titrated according to the best C. The patients were turned to prone position for further 18-20 h. For recruitability assessment, average value of PaO was slightly improved at PEEP 15 cmHO (68.0 ± 10.3 vs. 69.7 ± 7.9 mmHg, baseline vs. PEEP 15 cmHO; = 0.31). However, both PaCO and C worsened (PaCO: 72.5 ± 7.1 vs. 75.1 ± 9.0 mmHg; < 0.01. C: 17.5 ± 3.5 vs. 16.6 ± 3.9 ml/cmHO; = 0.05). Only four patients (20%) were considered lung recruitable. Individually titrated PEEP was higher than the baseline PEEP (8.0 ± 2.1 cmHO vs. 5 cmHO, < 0.001). After 18-20 h of prone positioning, investigated parameters were significantly improved compared to the baseline (PaO: 82.4 ± 15.5 mmHg. PaCO: 67.2 ± 6.4 mmHg. C: 20.6 ± 4.4 ml/cmHO. All < 0.001 vs. baseline). Lung recruitability was very low in COVID-19-associated severe ARDS. Individually titrated PEEP and prone positioning might improve lung mechanics and blood gasses.