Application of validated severity scores for pneumonia caused by SARS-CoV-2

Abstract

Objectives: Compare the accuracy of PSI, CURB-65, MuLBSTA and COVID-GRAM prognostic scores to predict mortality, the need for invasive mechanical ventilation in patients with pneumonia caused by SARS-CoV-2 and assess the coexistence of bacterial respiratory tract infection during admission.

Methods: Retrospective observational study that included hospitalized adults with pneumonia caused by SARS-CoV-2 from 15/03 to 15/05/2020. We excluded immunocompromised patients, nursing home residents and those admitted in the previous 14 days for another reasons. Analysis of ROC curves was performed, calculating the area under the curve for the different scales, as well as sensitivity, specificity and predictive values.

Results: A total of 208 patients were enrolled, aged 63±17 years, 57,7% were men; 38 patients were admitted to ICU (23,5%), of these patients 33 required invasive mechanical ventilation (86,8%), with an overall mortality of 12,5%. Area under the ROC curves for mortality of the scores were: PSI 0,82 (95% CI: 0,73-0,91), CURB-65 0,82 (0,73-0,91), MuLBSTA 0,72 (0,62-0,81) and COVID-GRAM 0,86 (0,70-1). Area under the curve for needing invasive mechanical ventilation was: PSI 0,73 (95% CI: 0,64-0,82), CURB-65 0,66 (0,55-0,77), MuLBSTA 0,78 (0,69-0,86) and COVID-GRAM 0,76 (0,67-0,85), respectively. Patients with bacterial co-infections of the respiratory tract were 20 (9,6%), the most frequent strains being Pseudomonas aeruginosa and Klebsiella pneumoniae.

Conclusions: In our study, the COVID-GRAM score was the most accurate to identify patients with higher mortality with pneumonia caused by SARS-CoV-2; however, none of these scores accurately predicts the need for invasive mechanical ventilation with ICU admission. The 10% of patients admitted presented bacterial respiratory co-infection.

Keywords: COVID-19; Coronavirus; Escalas pronósticas; Neumonía; Penumonia; Severity scores.