Effects of a chair positioning session in awake non-intubated COVID-19 pneumonia patients: a multicenter, observational, pilot study using lung ultrasound

Abstract BackgroundLung ultrasound (LUS) is a validated tool for the management of coronavirus disease 2019 (COVID-19)-related pneumonia. An awake prone positioning (PP) improves oxygenation and outcomes in COVID-19 non-intubated patients, but its tolerance remains an issue. A chair positioning (CP) may have beneficial effects on oxygenation and lung aeration. Thus, CP could be an easier alternative to PP. This study assessed the effects of a CP session on oxygenation (using SpO2:FiO2 ratio) and lung aeration (using lung reaeration score) changes in non-intubated COVID-19 patients. Methods An observational multicenter study was conducted in three university hospital intensive care units (ICUs). We retrospectively analyzed prospectively collected data from LUS exams performed before and after a CP session in non-intubated COVID-19 patients. Patients were divided into groups of responders or non-responders in terms of oxygenation and lung aeration.ResultsOf the 33 patients included in the study, 14 (44%) were oxygenation non-responders and 18 (56%) were oxygenation responders, and 13 (40.6%) and 19 (59.4%) patients were classified as lung aeration non-responders and responders, respectively. Changes in oxygenation and lung aeration before and after a CP session were not correlated (Pearson’s r = -0.19, p = 0.3, 95% CI: -0.5–0.17). The reaeration scores did not differ between oxygenation responders and non-responders (1 [-0.75–3.75] vs. 4, [-1–6], p = 0.41). The LUS score was significantly correlated with SpO2:FiO2 ratio before a CP session (Pearson’s r = 0.37, p = 0.04, 95% CI: 0.03–0.64) but not after (Pearson’s r = 0.17, p = 0.35, 95% CI: -0.19–0.50). Conclusion A CP session was associated with improved oxygenation and lung aeration in more than half of the non-intubated COVID-19 patients. However, oxygenation and lung aeration changes were not associated, suggesting that a CP session induces a ventilation:perfusion matching alteration.