COVID-19 Acute Respiratory Distress Syndrome (CARDS) is the most serious complication of COVID-19. The SARS-CoV-2 outbreaks rapidly saturated intensive care unit (ICU), forcing the application of non-invasive respiratory support (NIRS) in respiratory intermediate care unit (RICU). The primary aim of this study is to compare the patients’ clinical characteristics and outcomes (Helmet-Continuous Positive Airway Pressure (H-CPAP) success/failure and survival/death). The secondary aim is to evaluate and detect the main predictors of H-CPAP success and survival/death. A total of 515 patients were enrolled in our observational prospective study based on CARDS developed in RICU during the three Italian pandemic waves. All selected patients were treated with H-CPAP. The worst ratio of arterial partial pressure of oxygen (PaO₂) and fraction of inspired oxygen (FiO₂) PaO₂/FiO₂ during H-CPAP stratified the subjects into mild, moderate and severe CARDS. H-CPAP success has increased during the three waves (62%, 69% and 77%, respectively) and the mortality rate has decreased (28%, 21% and 13%). H-CPAP success/failure and survival/death were related to the PaO₂/FiO₂ (worst score) ratio in H-CPAP and to steroids’ administration. D-dimer at admission, FiO₂ and positive end expiratory pressure (PEEP) were also associated with H-CPAP success. Our study suggests good outcomes with H-CPAP in CARDS in RICU. A widespread use of steroids could play a role.

Background: COVID-19 Acute Respiratory Distress Syndrome (CARDS) is the major complication of COVID-19. The SARS-CoV-2 outbreaks rapidly saturating ICU beds, forcing the application of non-invasive respiratory support (NIRS) in respiratory intermediate care unit (RICU).Methods: 515 patients were enrolled in our observational prospective study based on CARDS developed in RICU during the three Italian pandemic waves (150, 180 and 185 patients respectively). All selected patients (aged 18-80) were treated with Helmet-Continuous Positive Airway Pressure (H-CPAP). The primary aim of the study is to compare the patients’ clinical characteristics and outcomes (H-CPAP success/failure and survival/death) during the three different pandemic waves. The secondary aim is to evaluate and detect the main predictors of the H-CPAP success and survival/death in patients selected by having CARDS criteria.Results: The worst ratio of arterial partial pressure of oxygen (PaO₂) and fraction of inspired oxygen (FiO₂) PaO₂/FiO₂ during H-CPAP stratified the subjects in mild (82-15.9%), moderate (202-39.2%) and severe (231-44.9%) CARDS. H-CPAP success has increased during the three waves (62%, 69% and 77% respectively) and the mortality rate has decreased (28%, 21% and 13%). H-CPAP success/failure and survival/death were related to the ratio PaO₂/FiO₂ (worst score) in H-CPAP and steroids administration. D-dimer at admission, FiO₂ in H-CPAP, and level of PEEP were also associated with H-CPAP success.Conclusions: Our study suggests good clinical outcomes with H-CPAP in CARDS in RICU. CARDS has a biphasic trend confirmed in all the three waves, with a worsening patients’ trend from admission to subsequent days of hospitalization. A widespread use of steroids in our center could play a role in achieving good clinical outcomes. The proper management during hospitalization by pulmonologist in RICU may affect these patients’ trend. We observed a significant improvement of prognosis in the three different waves: patients are found to be progressively slightly less severe.

Non-invasive respiratory support for acute hypoxemic respiratory failure (AHRF) remains controversial. Continuous positive airway pressure (CPAP) provides sustained positive end-expiratory pressure, while helmet interface (H-CPAP) may improve tolerance and re-duce air leaks. We aimed to evaluate clinical outcomes of H-CPAP delivered in a respira-tory intermediate care unit (RICU) by pulmonologists and identify early predictors of treatment failure. We conducted a prospective single-centre observational cohort study in-cluding consecutive adults with community-acquired pneumonia (CAP)-AHRF treated with H-CPAP in a RICU. H-CPAP success was defined as hospital discharge without in-vasive mechanical ventilation (IMV). Clinical, radiological, gas exchange, laboratory var-iables were collected at baseline and after 1 hour of H-CPAP. Among 1100 screened pa-tients, 198 met inclusion criteria. H-CPAP success occurred in 158/198 patients (79.8%), while overall in-hospital mortality was 9.1%. Success rates decreased with increasing AHRF severity. Lower haematocrit, bilateral pulmonary infiltrates, lower PaO₂/FiO₂ dur-ing H-CPAP, higher alveolar–arterial oxygen gradient, and higher APACHE II score were the main predictors of treatment failure. In selected patients with CAP-AHRF, H-CPAP delivered in a RICU was associated with high rates of avoidance of IMV and low in-hospital mortality. Early physiological and radiological variables identified patients at increased risk of H-CPAP failure with acceptable predictive performance.