Continuous Positive Airway Pressure in Elderly Patients with Severe COVID-19 Related Respiratory Failure

Abstract

The elderly population represents a high percentage of patients hospitalized for COVID-19 pneumonia and severe respiratory failure, for whom CPAP may be a treatment option. The aim of this study was to describe the CPAP support modalities and to explore factors associated with CPAP failure. In this retrospective study, 110 consecutive patients aged ≥ 75 years were enrolled. Median frailty score, baseline partial arterial pressure of oxygen to fraction of inspired oxygen ratio (P/F), and respiratory rate (RR) were 5, 108, and 30 cycles/min, respectively. Of the 110 patients that began CPAP treatment, 17 patients died within 72 h from baseline, while in 2 patients, CPAP was withdrawn for clinical improvement. Thus, of the 91 patients still on CPAP at day 3, 67% of them needed continuous CPAP delivery. Patients with RR ≥ 30 and with frailty score ≥ 5 had an odds ratio of continuous CPAP needing of 3 and 4, respectively. Patients unable to tolerate CPAP-free periods demonstrated higher mortality risk as compared to those able to tolerate intermittent CPAP (OR: 6.04, 95% CI 2.38−16.46, p < 0.001). The overall in-hospital mortality was 63.6%. Delirium occurred in 59.1%, with a mortality rate in this subgroup of 83.1%. In a time-varying Cox model, the hazard ratio of death was 2.9 in patients with baseline RR ≥ 30 cycle/min, 2.4 in those with baseline P/F < 100. In the same model, the hazard ratio of death was 20 in patients with delirium and a frailty score < 5 and 8.8 in those without delirium and with frailty ≥ 5, indicating a competitive effect between these two variables on the death risk. Conclusions: Respiratory impairment, frailty, and delirium predict treatment failure, with the latter two factors demonstrating a competitive effect on mortality risk. CPAP support may represent a feasible therapeutic option in elderly patients, although chances of a therapeutic benefit are markedly reduced in case of severe respiratory impairment, very frail baseline condition or delirium occurrence.

Keywords: COVID-19; CPAP; continuous positive airway pressure; elderly; ventilation.

Figure 1

Time course of mortality and delirium onset. Panel (a). Time course of mortality (continuous line) and 95% CI (dotted lines). Panel (b) Time course of delirium onset (continuous line) and 95% CI (dotted lines). Full vertical lines represent the time point when 50% of mortality/delirium were reached.

Figure 2

Illness-death model by baseline characteristics on transition to different states.