COVID-19 and acute respiratory failure treated with CPAP

Abstract

Introduction: Patients admitted with COVID-19 often have severe hypoxemic respiratory failure and it can be difficult to maintain adequate oxygenation with oxygen supplementation alone. There is a physiological rationale for the use of Continuous Positive Airway Pressure (CPAP), and CPAP could keep some patients off mechanical ventilation. We aimed to examine the physiological response to CPAP and the outcome of this treatment.

Method: Data from patients admitted with COVID-19 in spring 2020 and treated with CPAP were extracted from electronic medical records. CPAP was initiated on a medical ward when oxygen supplementation exceeded 10 l/min to maintain oxygen saturation (SpO2)≥ 92%. CPAP was administered with face masks on a continuous basis until stable improvement in oxygenation or until intubation or death.

Results: CPAP was initiated in 53 patients (35 men, 18 women) with a median (IQR) age of 68 (57-78) years. Nine patients did not tolerate the CPAP treatment. Median duration for the 44 patients receiving CPAP was 3 (2-6) days. The PaO2/FiO2 ratio was severely reduced to an average of 101 mmHg at initiation of treatment. A positive response of CPAP was seen on respiratory rate, p=0.002 and on oxygenation, p<0.001. 27% of the patients receiving CPAP avoided intubation, 29% were intubated, and 43% died. Of the patients with a ceiling of treatment in the ward (n=20) only 5% survived. Older age and high initial oxygen demand predicted treatment failure.

Conclusion: CPAP seems to have positive effect on oxygenation and respiratory rate in most patients with severe respiratory failure caused by COVID-19. The prognosis for especially elderly patients with high oxygen requirement and with a ceiling of treatment in the ward is poor.