Conclusions
Temperature >38 °C, LDH > 250 U/l, and d-dimer >1000 ng/mL were found to be independent risk factors for NI/I-VS in COVID-19 patients. In order to quickly identify patients likely at risk of developing a critical illness, inflammatory markers should be assessed upon hospital admission.
Methods
All consecutive patients admitted to the Infectious Diseases Unit and Intensive Care Unit (ICU) of Santa Maria Annunziata Hospital (Florence, Italy), from February 25 to April 25, 2020, with a confirmed COVID-19 diagnosis were enrolled in this retrospective cohort study. NI/I-VS was defined as the need for continuous positive airway pressure (CPAP) or bilevel positive airway pressure (BPAP) (non-invasive ventilation) or mechanical ventilation, not including low-flow systems of oxygen therapy such as the Venturi mask or nasal cannula.
Results
Ninety-seven patients were enrolled; 61.9% (60/97) were male and the median patient age was 64 years. The in-hospital mortality was 9.3%. Thirty-five of the 97 patients (36%) required ICU admission and 94.8% (92/97) were prescribed oxygen therapy: 10.8% (10/92) by nasal cannula, 44.5% (41/92) by Venturi mask, 31.5% (29/92) by CPAP, 2.2% (2/92) by BPAP, and 10.8% (10/92) by mechanical ventilation following intubation. On univariate analysis, patients with a body mass index >30, type II diabetes mellitus, and those presenting with dyspnoea, asthenia, SOFA score ≥2 points, PaO2/FiO2 <300, temperature >38 °C, increased levels of lactate dehydrogenase (LDH), alanine aminotransferase, and C-reactive protein, and a d-dimer >1000 ng/mL at admission more frequently underwent NI/I-VS. Multivariate logistic regression analysis confirmed temperature >38 °C (odds ratio (OR) 21.2, 95% confidential interval (95% CI) 3.5-124.5, p = 0.001), LDH >250 U/l (OR 15.2, 95% CI 1.8-128.8, p = 0.012), and d-dimer >1000 ng/mL (OR 4.5, 95% CI 1.2-17.3, p = 0.027) as significantly associated with the requirement for NI/I-VS. A non-significant trend (p = 0.051) was described for PaO2/FiO2 <300. Conclusions: Temperature >38 °C, LDH > 250 U/l, and d-dimer >1000 ng/mL were found to be independent risk factors for NI/I-VS in COVID-19 patients. In order to quickly identify patients likely at risk of developing a critical illness, inflammatory markers should be assessed upon hospital admission.