Predictive factors for success of awake proning in hypoxemic respiratory failure secondary to COVID-19: A retrospective cohort study

Abstract

Background Awake prone positioning has been recommended as an adjunctive measure in spontaneously breathing patients with hypoxemic respiratory failure during the COVID-19 pandemic. It remains uncertain as to how long this should be implemented, what variables to follow and who would be the ideal candidates for this adjunctive therapy. Methods A retrospective chart review of patients admitted from April to August 2020 within our institution with multifocal pneumonia and hypoxemic respiratory failure secondary to COVID-19 who underwent awake-proning for at least 3 hours was conducted. Results Improvement in respiratory parameters including ROX (SpO2/Fio2/ Respiratory Rate) indices and inflammatory markers within 4 days of institution of awake proning predicted a higher chance for success of this strategy in preventing need for mechanical ventilation. Moreover, benefits of awake proning were limited to patients with mild to moderate ARDS. Conclusions Awake prone positioning can be safely performed with improvement in oxygenation. However, its institution may be beneficial only in patients with mild to moderate ARDS and requires careful evaluation of respiratory parameters and serum inflammatory markers to avoid a delay in endotracheal intubation and consequent increase in mortality rates.

Noninvasive respiratory support for acute respiratory failure due to COVID-19

“…Prone positioning in spontaneously breathing patients improves oxygenation and lowers inspiratory effort [94 ▪▪ ] and respiratory rate, but the improvement is often transient, and only a minority of patients show sustained benefit after resupination [95–123] (Table 4).…”

Pulse oximetry for the diagnosis and management of acute respiratory distress syndrome

“… 83 Other studies support the importance of the ROX index in COVID-19, although some identified a different ROX index cutoff as having optimal sensitivity and specificity for successful use of HFNO 84 , 85 , 86 , 87 , 88 , 89 from that of previous studies of severe pneumonia. 11 , 77 The ROX index is also predictive of the success of awake prone positioning 90 , 91 and of non-invasive mechanical ventilation for COVID-19 pneumonia. 92 Differences in the exact ROX index value that predicts successful use of non-invasive respiratory support might be related to different timing of measurements, varying clinician thresholds for intubation during the pandemic, the effect of PEEP for patients on non-invasive mechanical ventilation, and differences in the setting in which patients on HFNO were managed (ICU, wards, or emergency department), as well as demographic and comorbidity differences among patient populations.…”

The Role of Noninvasive Respiratory Management in Patients with Severe COVID-19 Pneumonia

“…Awake self-proning has been described in small observational, mostly retrospective cohorts in non-COVID-19 [ 115 , 116 ] and COVID-19 [ 117 , 118 , 119 , 120 , 121 , 122 , 123 , 124 , 125 , 126 , 127 , 128 , 129 ] patients with acute hypoxemia. Turning the awake hypoxemic patient prone was feasible, safe [ 117 , 120 , 125 , 126 , 130 ] and in most cases improved oxygenation [ 117 , 119 , 120 , 125 , 126 , 128 , 129 ], with a mean PaO 2 /FiO 2 difference of 51.3 mmHg (95% CI 13.91–88.67) [ 131 ]. Oxygenation improvement was sustained after re-supination in patients in whom the prone position was combined with noninvasive respiratory strategies (HFNO or NIV) [ 117 , 126 ].…”