ABSTRACT
Rationale Awake proning has been described as an effective intervention to improve oxygenation in nonintubated patients with acute hypoxemic respiratory failure secondary to coronavirus disease 2019 (COVID-19). However, it remains unclear whether awake proning can prevent intubation in these patients. A major concern is that delaying intubation with awake proning may potentially lead to worse outcomes. Our study aimed to identify the clinical parameters indicative of successful awake proning that prevents intubation. Methods We identified 54 patients who met the criteria for acute hypoxemic respiratory failure and underwent awake proning, with a confirmed diagnosis of COVID-19 at a single center from April to August, 2020. All patients had radiographic evidence of bilateral multifocal ground-glass opacities. Acute hypoxemic respiratory failure was defined as oxygen saturations less than 88% on room air that required supplemental oxygen, high flow nasal cannula, or non-invasive positive pressure ventilation. Table 1 demonstrates a comparison between patients who did not require intubation and those who did. We used t-test or Wilcoxon rank-sum test for continuous variables and Chi-square test or Fisher's exact test for categorical variables for statistical analysis. Results 31 patients (57%) did not require mechanical ventilation. Baseline demographics and comorbidities were similar between the two groups. The group that did not require intubation had higher SpO2/FiO2 ratios at the beginning of awake proning and throughout the next 4 days. In contrast, the group that required intubation had a lower SpO2/FiO2 ratio at baseline, which did not improve during the next 4 days. Additionally, respiratory rate improved with awake proning in the group that did not require intubation 4 hours after awake proning started. Mortality was higher among the patients who were intubated. Serum levels of inflammatory biomarkers were elevated in both groups. However, d-dimer and lactate dehydrogenase levels were significantly lower in the group that did not require intubation by day 4. Conclusions Awake proning was associated with decreased intubation rates in patients with less severe acute hypoxemic respiratory failure. Delaying intubation in patients with severe acute hypoxemic respiratory failure may lead to worse outcomes. Clinical parameters that may aid as decision tools to predict failure of awake proning include SpO2/FiO2 ratio, respiratory rate, and biomarkers within 4 days of initiation of awake proning.