Novel tools for evaluating COVID-19 at the emergency department: Surfactant protein D level and CHARISMA score

To investigate the serum surfactant protein D (SP-D) level required to determine the diagnosis and prognosis of coronavirus disease 2019 (COVID-19), and create a new scale for disease prognosis prediction.

This study was conducted among 64 patients with COVID-19 symptoms and 16 healthy volunteers. The participants were assessed by comparing "Controls/Patients", "PCR-negative/PCR-positive", "Simple COVID-19/Acute respiratory distress syndrome (ARDS)-accompanied COVID-19", "Mild ARDS/Moderate-severe ARDS", and "Survived/Dead" subgroups. Serum SP-D levels and pulmonary infiltration area (volume and percentage) measurements on CT were compared between the groups. A new scale, the "CHARISMA Score", was created by logistic regression method for a complete prognosis assessment. This includes confusion, heart rate, age, respiratory rate, percentage of infiltration on CT, serum SP-D level, mean arterial pressure and SaO₂.

Serum SP-D levels differed significantly across the groups. There was a strong correlation between SP-D levels and infiltration volumes. CHARISMA scores were higher in the severe than in the mild ARDS group and in patients who died than in survivors. In the receiver operating characteristic curve analysis of the CHARISMA scores, a cutoff value of 4 indicated mortality.

Serum SP-D levels can be used to determine COVID-19 diagnosis and prognosis, and the CHARISMA score can be used to predict prognosis and mortality risk in patients with COVID-19 pneumonia.