Aim. To describe associated factors to 30-day mortality of patients treated with Non-invasive respiratory therapies (NIRT) due to COVID-19 respiratory failure in the Madrid Area.
Methods. Observational study of patients treated by Pneumologists with NIRT during the first five waves of COVID-19 in six third level hospitals from March 2020 to August 2021, outside the ICU. NIRT were classified as (1) high flow nasal cannula (HFNC), (2) continuous positive airway pressure (CPAP), (3) bi-level positive airway pressure (BIPAP), and (4) combined therapy (HFNC + PAP). Sociodemographic data was retrieved as well as pre-existent chronic respiratory diseases. A multivariate binary logistic regression model was performed to determine 30-day mortality associated factors.
Results. A total of 2.085 patients were included, 1.295 men (62.1%), mean age of 67.5 ± 14.0 years; 870 had a do-not-intubate (DNI) order (41.7%), 30-day mortality was of 824 (39.5%). Highest mortality was observed in the second wave (44.4%, p<0.01). Figure 1 presents NIRT trends of use during the first five waves, and Table 1 presents the multivariate model.
Conclusions. Older age, obstructive sleep apnea and DNI order associated to a higher mortality and combined therapy of HFNC and PAP to a lower 30-day mortality.
| RR | CI95% | p-value | |
| Age | 1.06 | 1.05 - 1.07 | 0.0001 |
| Male sex | 0.86 | 0.70 - 1.08 | 0.19 |
| Do-not-intubate-order | 3.27 | 2.56 - 4.17 | 0.0001 |
| COPD | 0.95 | 0.70 - 1.27 | 0.72 |
| Asthma | 0.91 | 0.72 - 1.15 | 0.57 |
| Obstructive sleep apnea | 1.48 | 1.08 - 2.04 | 0.02 |
| Diabetes | 0.91 | 0.72 - 1.15 | 0.42 |
| HFNC | 0.69 | 0.44 - 1.09 | 0.11 |
| CPAP | 1.18 | 0.74 - 1.87 | 0.49 |
| BIPAP | 0.85 | 0.58 - 1.24 | 0.40 |
| Combined therapy | 0.58 | 0.36 - 0.92 | 0.02 |