Incidence and Predictive Value of Thrombocytopenia in Patients with Severe Community Acquired Pneumonia

Abstract

Summary Introduction. Thrombocytopenia is frequently encountered in intensive care unit (ICU) patients. The cause of thrombocytopenia is multifactorial, it develops as a result of infection, inflammation and depletion of coagulation factors. Therefore, thrombocytopenia could potentially serve as an indicator of severity of the illness and an outcome predictor in patients with severe community-acquired pneumonia (CAP). Aim of the study. To determine incidence and predictive value of thrombocytopenia in ICU patients with severe CAP. Material and methods. We carried out a retrospective study based on clinical records from patients admitted to the Pauls Stradins Clinical University Hospital Intensive Care and Reanimation Unit from 2011 to 2014. Thrombocytopenia was defined as platelet count ≤150×109/L. Results. A total of 98 patients were included in this study, 58 (59%) men and 40 (41%) women. The mean (±SD) age of patients was 61±17.9 years, 54% died and 46% survived. 57 patients (58%) developed thrombocytopenia, in 58% it was present at the admission to ICU, and 42% developed thrombocytopenia during their stay in ICU. The lowest platelet count, in survivors was on fifth day in ICU, while in non-survivors on fourth day in ICU. Platelet count on admission to ICU (ROC AUC: 0.610, p=0.095) had lower discriminative power for ICU mortality than SOFA score (ROC AUC: 0.729, p=0.001) and CURB-65 score (ROC AUC: 0.680, p=0.006). Patients with thrombocytopenia at any point of ICU stay had higher hospital mortality in comparison to patients without thrombocytopenia. (36 (63.1%) vs 17 (41.1%), p=0.041). In thrombocytopenic patients non-resolution of thrombocytopenia during the ICU stay was associated with higher mortality (OR 5.5; 95% CI, 1.6-18.7, p=0.006). After adjusting for age, gender and SOFA score, non-resolution of thrombocytopenia remained to be an independent mortality predictor (OR 8, 95% CI 1.7-37, p=0.008) Conclusions. Thrombocytopenia is frequently encountered in patients with severe CAP. Thrombocytopenia at any point of ICU stay is associated with higher hospital mortality. Resolution of thrombocytopenia is associated with better clinical outcome.