Background The coronavirus disease 2019 (COVID-19) can result in severe pneumonia, leading to acute respiratory distress syndrome, which are treated using continuous positive airway pressure (CPAP). Patients must be evaluated quickly to commence early CPAP if required.

Aim To identify patients with COVID-19 in the emergency department (ED) who require early CPAP, using vital signs measurements during triage.

Method This was a retrospective, observational, single-centre cohort study of patients with COVID-19 admitted to the ED of a university hospital in Lombardy, Italy, between 21 February 2020 and 30 April 2020. These patients were divided into two groups: those who required CPAP and those did not require CPAP. Recordings of their vital signs were retrieved from triage medical records. The vital signs values recorded in the two groups on their arrival at the ED were compared.

Results Of 601 patients, 120 (20%) required CPAP. It was identified that the typical characteristics of patients requiring early CPAP were: male (P=.013) with a median age of 68 years (P=.000), oxygen saturation of 92% (P=.000), temperature ≥38°C (P=.008), respiratory rate of 26 breaths per minute (P=.000) and had received pre-hospital oxygen therapy before arriving at the ED (P=.000). The CPAP group was divided into two subgroups: patients who had received pre-hospital oxygen therapy and those who had not. The median respiratory rate values between the two subgroups presented a statistically significant difference (P=.004).

Conclusion This study identified the characteristics of a typical patient with COVID-19 who requires early CPAP. Based on the results, the authors have devised a triage flow chart that uses selected vital signs measurements (oxygen saturation, respiratory rate and receipt of pre-hospital oxygen therapy) to identify patients requiring early CPAP. This flow chart should be trialled in a prospective study before it is used to inform clinical decision-making.