Severity of respiratory failure at admission and in-hospital mortality in patients with COVID-19: a prospective observational multicentre study
Giovanni Sotgiu,
Pierachille Santus,
Dejan Radovanovic,
Laura Saderi,
Pietro Marino,
Chiara Cogliati,
Giuseppe De Filippis,
Maurizio Rizzi,
Elisa Franceschi,
Stefano Pini,
Fabio Giuliani,
Marta Del Medico,
Gabriella Nucera,
Vincenzo Valenti,
Francesco Tursi
Affiliations
Giovanni Sotgiu
Dipartimento di Scienze Mediche, Chirurgiche e Sperimentali. Via Padre Manzella, 4—07100, Università degli Studi di Sassari, Sassari, Italy
Pierachille Santus
Department of Biomedical and Clinical Sciences (DIBIC), Università degli Studi di Milano, Milano, Italy
Dejan Radovanovic
Division of Respiratory Diseases, ASST Fatebenefratelli-Sacco, Via G.B. Grassi 74—20157, Ospedale Luigi Sacco-Polo Universitario, Milano, Italy
Laura Saderi
Dipartimento di Scienze Mediche, Chirurgiche e Sperimentali. Via Padre Manzella, 4—07100, Università degli Studi di Sassari, Sassari, Italy
Pietro Marino
Department of Medicine and Rehabilitation, Division of Emergency Medicine, ASST Fatebenefratelli-Sacco, Piazzale Principessa Clotilde, 3—20121, Ospedale Fatebenefratelli e Oftalmico, Milano, Italy
Chiara Cogliati
Division of Internal Medicine —ASST Fatebenefratelli-Sacco, Via G.B. Grassi 74—20157, Ospedale Luigi Sacco-Polo Universitario, Milano, Italy
Division of Respiratory Diseases, ASST Fatebenefratelli-Sacco, Via G.B. Grassi 74—20157, Ospedale Luigi Sacco-Polo Universitario, Milano, Italy
Elisa Franceschi
Department of Biomedical and Clinical Sciences (DIBIC), Università degli Studi di Milano, Milano, Italy
Stefano Pini
Department of Biomedical and Clinical Sciences (DIBIC), Università degli Studi di Milano, Milano, Italy
Fabio Giuliani
Department of Health Bioscience—Respiratory Unit, Policlinico di San Donato, IRCCS—Via Rodolfo Morandi, 30—20097, San Donato Milanese, Università degli Studi di Milano, Milano, Italy
Marta Del Medico
Division of Internal Medicine —ASST Fatebenefratelli-Sacco, Via G.B. Grassi 74—20157, Ospedale Luigi Sacco-Polo Universitario, Milano, Italy
Gabriella Nucera
Department of Medicine and Rehabilitation, Division of Emergency Medicine, ASST Fatebenefratelli-Sacco, Piazzale Principessa Clotilde, 3—20121, Ospedale Fatebenefratelli e Oftalmico, Milano, Italy
Vincenzo Valenti
Department of Health Bioscience—Respiratory Unit, Policlinico di San Donato, IRCCS—Via Rodolfo Morandi, 30—20097, San Donato Milanese, Università degli Studi di Milano, Milano, Italy
Francesco Tursi
Dipartimento Medico, USC Pneumologia, USS Servizio di Pneumologia, Ospedale di Codogno, Azienda Socio Sanitaria Territoriale di Lodi, Lodi, Italy
Objectives COVID-19 causes lung parenchymal and endothelial damage that lead to hypoxic acute respiratory failure (hARF). The influence of hARF severity on patients’ outcomes is still poorly understood.Design Observational, prospective, multicentre study.Setting Three academic hospitals in Milan (Italy) involving three respiratory high dependency units and three general wards.Participants Consecutive adult hospitalised patients with a virologically confirmed diagnosis of COVID-19. Patients aged <18 years or unable to provide informed consent were excluded.Interventions Anthropometrical, clinical characteristics and blood biomarkers were assessed within the first 24 hours from admission. hARF was graded as follows: severe (partial pressure of oxygen to fraction of inspired oxygen ratio (PaO2/FiO2) <100 mm Hg); moderate (PaO2/FiO2 101–200 mm Hg); mild (PaO2/FiO2 201–300 mm Hg) and normal (PaO2/FiO2 >300 mm Hg).Primary and secondary outcome measures The primary outcome was the assessment of clinical characteristics and in-hospital mortality based on the severity of respiratory failure. Secondary outcomes were intubation rate and application of continuous positive airway pressure during hospital stay.Results 412 patients were enrolled (280 males, 68%). Median (IQR) age was 66 (55–76) years with a PaO2/FiO2 at admission of 262 (140–343) mm Hg. 50.2% had a cardiovascular disease. Prevalence of mild, moderate and severe hARF was 24.4%, 21.9% and 15.5%, respectively. In-hospital mortality proportionally increased with increasing impairment of gas exchange (p<0.001). The only independent risk factors for mortality were age ≥65 years (HR 3.41; 95% CI 2.00 to 5.78, p<0.0001), PaO2/FiO2 ratio ≤200 mm Hg (HR 3.57; 95% CI 2.20 to 5.77, p<0.0001) and respiratory failure at admission (HR 3.58; 95% CI 1.05 to 12.18, p=0.04).Conclusions A moderate-to-severe impairment in PaO2/FiO2 was independently associated with a threefold increase in risk of in-hospital mortality. Severity of respiratory failure is useful to identify patients at higher risk of mortality.Trial registration number NCT04307459
