Adaptation of a respiratory service to provide CPAP for patients with COVID-19 pneumonia, outside of a critical care setting, in a district general hospital

Abstract

Introduction: One-hundred and forty patients at Croydon University Hospital received continuous positive airway pressure (CPAP) on a specialist respiratory ward, as a bridge to invasive mechanical ventilation (IMV) or as a ceiling of care for COVID-19. This retrospective study aimed to outline service expansion, patient characteristics and explore risk factors in outcomes.

Results: Mean age of patients on CPAP was 64 years (standard deviation 12). The median number of days from admission to CPAP initiation was 1 day (interquartile range (IQR) 0-3), and time before successful wean off CPAP was 4 days (IQR 2-6). Twenty-eight-day mortality was 64%. Thirty-four per cent of patients went onto require IMV, 24% improved off CPAP and 41% were palliated. The 28-day non-survivor group were of older age, had statistically significant higher admission creatinine and higher peak oxygen requirement. Age above 65 years was associated with higher mortality (odds ratio 5.9; 95% confidence interval 2.63-13.3).

Conclusion: CPAP is a viable ceiling-of-treatment option in those unsuitable for ventilation, and may even avoid the need for ventilation in others. Duration on CPAP may be useful for service provision to predict resource allocation. The rapidity from admission to CPAP initiation highlights the need for early ceilings of care to be established.

Keywords: COVID-19; CPAP; SARS-CoV-2; continuous positive airway pressure; service adaptation.

Fig 1.

Difference in means between improved, invasive mechanical ventilation and end-of-life outcome groups using one-way ANOVA (95% confidence interval for the mean). a) Creatinine vs outcome; p=0.008; Tukey's test IMV–EOL. b) Partial pressure of oxygen:fraction of inspired oxygen at start of continuous positive airway pressure vs outcome; p=0.006; Tukey's test IMV–EOL and improved–IMV. c) Highest positive end-expiratory pressure required vs outcome; p<0.001; Tukey's test improved–EOL and improved–IMV. d) Highest fraction of inspired oxygen required vs outcome; p<0.001; improved–IMV and improved–EOL. CPAP = continuous positive airway pressure; EOL = end-of-life; FiO₂ = fraction of inspired oxygen; IMV = invasive mechanical ventilation; PEEP = positive end-expiratory pressure; P:F = partial pressure of oxygen:fraction of inspired oxygen.