Predictors Of Successful Outcome Of Self-Proning And High Flow Nasal Oxygen Therapy In Patients With COVID-19 Pneumonia: A Retrospective Analysis

Abstract

Background: Proning improves oxygenation and outcome in intubated patients with acute respiratory distress syndrome (ARDS). Awake self proning position (SPP) may lead to clinical improvement in COVID-19 cases with severe hypoxemia. We describe our experience of the impact of awake SPP with high flow nasal oxygen (HFNO) in COVID-19 patients on oxygenation and survival. Methods: A retrospective study of patients with moderate to severe ARDS due to COVID-19 pneumonia treated with SPP-HFNO admitted from May to July 2020 to ICU. The primary outcomes were avoidance of invasive or non-invasive ventilation or death. The secondary outcomes were improvement of oxygenation (SpO2), reduction in respiratory rate (RR), and/or reduction in heart rate (HR) after at least 30 minutes of SPP-HFNO. Results: A total of 110 ICU patients received SPP-HFNO and full data was available on 71 patients. The median age was 55 years with male predominance at 86%. The success group had lower APACHE II score (12.47 vs. 16.97, p<0.001), lower ICU-LOS (6.21 vs 13.19, p<0.001), higher pre and post SpO2 (90.64 vs 88.42, p=0.015 and 96.09 vs 93.22, p<0.001), and lower pre HR (91.03 vs. 99.08, p=0.04). The survival rate was much higher in HFNO & SPP successful group (97% vs. 51%, p<0.001). The significant covariates in the success group were lower APACHE II score (HR=0.91), lower WBC (HR=0.88), lower post-SPP RR (HR=1.40), and treatment with convalescent plasma (HR=2.33).Conclusion: Awake SPP-HFNO in patients with moderate to severe COVID-19 pneumonia is associated with improved oxygenation, reduced intubation rate, and improved survival.