Predictors of mortality in COVID-19 patients requiring CPAP

Background: Continuous positive airway pressure (CPAP) has been shown to be an effective management strategy in treating patients with moderate to severe COVID-19 related ARDS1. Methods: We retrospectively analysed all patients with COVID-19 pneumonia who received CPAP from 1/10/20 to 14/12/20 in our Hospital, assessing survival rates and predictors of mortality. Results: A total of 60 patients with COVID received CPAP during this period. Mean age of patients was 69 years and 68% were male. Median duration of CPAP was 6 days. Overall survival rate in all patients was 32%. 17 (28%) patients survived on CPAP alone (responders). However, 30 (50%) died after just receiving CPAP (non-responders) and 13 (22%) required intubation following CPAP. The patients who were responders were significantly younger than non-responders (Mean=61 vs 76, p=<0.05). The median 4C mortality scores2 were lower in responders vs non-responders (Median 4C= 10 vs 13, p<0.05). 73% of non-responders had 2 or more co-morbidities compared to 18% of responders. The patients who were for full escalation at the time of starting CPAP had an overall survival rate of 50%, while the survival rate was only 11% in patients who weren’t for intubation. There were no differences in characteristics between responders and intubated patients. All 12 patients who started CPAP after acquiring COVID in hospital died. Conclusion: Age and 4C mortality score can be useful to guide decision to commence CPAP. There is high mortality in patients deemed not suitable for intubation, who received CPAP. Hospital acquired COVID has a poor prognosis and is likely related to burden of co-morbidities and frailty. Larger studies could help refine predictors of successful CPAP treatment in COVID-19.