Can thrombocytosis or thrombocytopenia predict complicated clinical course and 30-days mortality in patients with pneumonia?

Background/aim: While several different scoring systems aim to determine the clinical outcomes for patients with pneumonia, there is limited emphasis on the platelet count. This study investigated the relationships between thrombocyte count and 30-day mortality and complicated clinical course of patients with pneumonia. Materials and methods: This prospective cross-sectional study enrolled patients over 18 years old with a diagnosis of pneumonia in the emergency department for six months. The primary outcome was to establish the relationship between platelet count, mortality, complicated clinical course, and initial vital parameters on admission. The secondary outcome was comparing the platelet count with mortality and complicated clinical course during the hospital stay. Results: Four hundred-five patients were included (58.8% male, mean age 75.1 ± 12.7 years). On admission, thrombocytosis was observed in 14.1% and thrombocytopenia in 4.2%. There was no difference between the 30-day mortality according to the platelet count at admission and follow-up. Patients who developed thrombocytopenia during follow-up needed more intensive care admissions, invasive mechanical ventilation, noninvasive mechanical ventilation, and vasopressor treatment, while patients with thrombocytosis needed invasive mechanical ventilation more frequently. Conclusion: Neither thrombocytopenia nor thrombocytosis is not associated with 30-day mortality in ED patients with pneumonia. Thrombocytopenia during follow-up was associated with a higher incidence for a complicated clinical course.