AUTHOR=Sang Ling , Zheng Xia , Zhao Zhanqi , Zhong Min , Jiang Li , Huang Yongbo , Liu Xiaoqing , Li Yimin , Zhang Dingyu 

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

JOURNAL=Frontiers in Medicine

VOLUME=7

YEAR=2021

URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2020.603943

DOI=10.3389/fmed.2020.603943

ISSN=2296-858X

ABSTRACT=<p><bold>Background:</bold> 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.</p><p><bold>Methods:</bold> Twenty patients who met the inclusion criteria were studied retrospectively (PaO<sub>2</sub>/FiO<sub>2</sub> 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 <italic>via</italic> the improvement of PaO<sub>2</sub>, PaCO<sub>2</sub>, and static respiratory system compliance (C<sub>stat</sub>) from low to high PEEP (5–15 cmH<sub>2</sub>O). Patients were considered recruitable if two out of three parameters improved. Subsequently, PEEP was titrated according to the best C<sub>stat</sub>. The patients were turned to prone position for further 18–20 h.</p><p><bold>Results:</bold> For recruitability assessment, average value of PaO<sub>2</sub> was slightly improved at PEEP 15 cmH<sub>2</sub>O (68.0 ± 10.3 vs. 69.7 ± 7.9 mmHg, baseline vs. PEEP 15 cmH<sub>2</sub>O; <italic>p</italic> = 0.31). However, both PaCO<sub>2</sub> and C<sub>stat</sub> worsened (PaCO<sub>2</sub>: 72.5 ± 7.1 vs. 75.1 ± 9.0 mmHg; <italic>p</italic> &lt; 0.01. C<sub>stat</sub>: 17.5 ± 3.5 vs. 16.6 ± 3.9 ml/cmH<sub>2</sub>O; <italic>p</italic> = 0.05). Only four patients (20%) were considered lung recruitable. Individually titrated PEEP was higher than the baseline PEEP (8.0 ± 2.1 cmH<sub>2</sub>O vs. 5 cmH<sub>2</sub>O, <italic>p</italic> &lt; 0.001). After 18–20 h of prone positioning, investigated parameters were significantly improved compared to the baseline (PaO<sub>2</sub>: 82.4 ± 15.5 mmHg. PaCO<sub>2</sub>: 67.2 ± 6.4 mmHg. C<sub>stat</sub>: 20.6 ± 4.4 ml/cmH<sub>2</sub>O. All <italic>p</italic> &lt; 0.001 vs. baseline).</p><p><bold>Conclusions:</bold> Lung recruitability was very low in COVID-19-associated severe ARDS. Individually titrated PEEP and prone positioning might improve lung mechanics and blood gasses.</p>