Treatment with Non-invasive respiratory support in severe COVID-19: Clinical effectiveness observational study

Introduction: The study aimed to analyse the clinical response and short-term outcomes with the use of high-flow oxygen therapy (HFOT), non-invasive mechanical ventilation (NIMV) with bilevel positive airway pressure, or continuous positive airway pressure (CPAP) in severe COVID-19 patients. Methods: We conducted an observational, prospective, single-center study, approved by Ethics Committee of “Instituto de Investigación Sanitaria Fundación Jiménez Díaz” (EO102-20-HRJC). We included a total of 130 patients ≥18 years-old, with proved SARS-CoV-2 infection and secondary Acute Respiratory Failure (ARF) that required treatment with Non-invasive Respiratory Support (NIRS). We collected data about population demographic characteristics, clinical factors, and evolution during the incoming. A baseline of patients treated with HFO, CPAP and NIMV were compared with one-way ANOVA test, while categorical variables were expressed as numbers and percentages and were compared using the chi-square test or Fisher’s exact test when appropriate. Results: The cohort was distributed as follows: CPAP 54.6% (n = 71), NIMV 30% (n = 39), HFO 15.4% (n = 20). There were no differences between NIRS subgroups regarding age, comorbidity, or functional status. At the beginning of NIRS treatment, PaO2/FiO2 value was 149.3 ± 69.7. After 24 hours, PaO2/FiO2 was significantly higher in the CPAP group (CPAP vs NIMV, p-value = 0.0042; CPAP vs HFO, p-value = 0.000169). The overall ICU admission evaded rate was 69.1% and TF rate was 43.8%, without differences between the three therapies (p-value = 0.281). The mortality rate was 37.2%, without significant differences between subgroups. Conclusions: Our data suggest that CPAP versus treatment with NIMV or HFO improves PaO2/FiO2 rate in severe ARF patients, significantly reducing ICU admission. No differences were observed in mortality or therapeutic failure.