ABSTRACT
Introduction: COVID-19 can lead to acute respiratory failure (ARF) requiring admission to intensive care unit (ICU). This study analyzes COVID-19 patients admitted to the ICU, according to the initial respiratory support. Its main aim is to determine if the use of combination therapy: high-flow oxygen system with nasal cannula (HFNC) and non-invasive ventilation (NIV), is effective and safe in the treatment of these patients. Methods: Retrospective observational study with a prospective database. All COVID-19 patients, admitted to the ICU, between March 11, 2020, and February 12, 2022, and who required HFNC, NIV, or endotracheal intubation with invasive mechanical ventilation (ETI-IMV) were analyzed. HFNC failure was defined as therapeutic escalation to NIV, and NIV failure as the need for ETI-IMV or death in the ICU. The management of patients with non-invasive respiratory support included the use of combined therapy with different devices. The study period included the first six waves of the pandemic in Spain. Results: 424 patients were analyzed, of whom 12 (2.8%) received HFNC, 397 (93.7%) NIV and 15 (3.5%) ETI-IMV as first respiratory support. PaO2/FiO2 was 145 ± 30, 119 ± 26 and 117 ± 29 mmHg, respectively (p = 0.003). HFNC failed in 11 patients (91.7%), who then received NIV. Of the 408 patients treated with NIV, 353 (86.5%) received combination therapy with HFNC. In patients treated with NIV, there were 114 failures (27.9%). Only the value of SAPS II index (p = 0.001) and PaO2/FiO2 (p < 0.001) differed between the six analyzed waves, being the most altered values in the 3rd and 6th waves. Hospital mortality was 18.7%, not differing between the different waves (p = 0.713). Conclusions: Severe COVID-19 ARF can be effectively and safely treated with NIV combined with HFNC. The clinical characteristics of the patients did not change between the different waves, only showing a slight increase in severity in the 3rd and 6th waves, with no difference in the outcome.
