Novel Severity Scoring System for Pneumonia at ICU Admission

A parsimonious score system that accurately identified elderly and non-elderly patients with pneumonia at highest risk for mortality in the intensive care unit (ICU) was developed and the data on its efficacy was published in Clinical Infectious Diseases.

Because studies evaluating the accuracy of severity scores in ICU patients is limited, researchers conducted a prospective cohort study to determine the performance of severity scores as predictors of mortality in critically-ill patients admitted with pneumonia. The investigators analyzed data from ICU severity scores (Simplified Acute Physiology Score 3 [SAPS 3] and quick Sepsis Related Organ Failure Assessment [qSOFA]), prognostic scores of pneumonia (CURB-65 and CRB-65), clinical and epidemiologic variables in the first 6 hours of hospitalization of patients in a general ICU.          

Between August 2015 and July 2018, researchers included data from 200 patients with a median age of 81 years and who received care in a tertiary care facility in Brazil. Patients were primarily admitted from the emergency department (65%) with community-acquired pneumonia (80.5%); the cohort was also predominantly women (52%).

Investigators found poor discriminative performance in predicting mortality with SAPS 3, CURB-65, CRB-65 and qSOFA. Using multivariate regression, variables independently associated with mortality were identified and used to develop a novel pneumonia specific ICU severity score: the Pneumonia SHOCK score. This score outperformed SAPS3, qSOFA, CURB-65 and CRB-65 with an area under the curve of 0.80 vs 0.74, 0.64, 0.63 and 0.63, respectively (P <.006). The discriminate function of the Pneumonia SHOCK score was then validated in an external multicenter cohort of critically-ill patients admitted with community acquired pneumonia and had an area under the curve of 0.81.

The study had multiple strengths including, a well-characterized elderly cohort with external validation and comparable mortality rate to other studies. However, there were also limitations, such as potential unknown patient and healthcare provider factors that were not readily apparent because this was a single-center study. Also, the study population may have specific factors that independently improve score performance. In addition, delays in appropriate antibiotic therapy were not evaluated and may have affected mortality rates.

According to investigators, “the composite score developed here outperformed prior scores analyzed in our cohort, demonstrates excellent discriminate function in a distinct validation cohort and offers an alternative prognostic tool with robust performance to predict mortality in those with pneumonia.” Furthermore, the performance of the score relies on simple, readily available data at the time of admission that accurately identifies those at highest risk of ICU death.

Reference

Azevedo do Carmo T, Bonifácio Brige Ferreira I, Carvalho de Menezes R, et al. Derivation and validation of a novel severity scoring system for pneumonia at ICU admission [published March 8 2020]. Clin Infect Dis. doi:10.1093/cid/ciaa183