Hemogram values in community acquired pneumonia

Background: Hemogram or complete blood count (CBC) is one of essential laboratory tests either in the diagnosis or assessment of community acquired pneumonia (CAP) patients. Objective: To assess the role of leukocyte and platelet count in determination of the severity and outcome of CAP. Patients and methods: This is a prospective descriptive study which was done on 95 patients aged ⩾18 years, who were diagnosed to have CAP. Clinical, laboratory and chest radiographic finding data were collected for each patient. Assessment of CAP severity using Pneumonia Severity Index (PSI) and CRB-65 score (the confusion, respiratory rate, blood pressure plus age ⩾65) was done for all enrolled patients. Thrombocytopenia and thrombocytosis were defined as platelet count <100,000/μL and 400,000/μL, respectively. Leukopenia and leukocytosis were defined as WBC count of <4000/μL and >11,000/μL, respectively. The outcome variable was in-hospital mortality. Results: In this study 75 (78.9%) of patients improved (survivors) and the outcome of 20 (21.1%) patients was in-hospital mortality (non-survivors). PS-index score III, IV and V and CRB-65 score II, III and IV were significantly higher in patients with thrombocytosis (P < 0.006, P < 0.04 respectively) while there was no significant difference as regards leukocyte count in both scores. Also both thrombocytopenia and thrombocytosis were significantly higher in non survivors (P < 0.006) while there was no significant difference as regards leukocytosis. Platelet count has a significant positive correlation with CRB-65 and PS index with P-value 0.001 for each and r-value 0.236, 0.259 respectively. Conclusion: On assessment of CAP patients at admission; platelet count could be considered to be a valuable indicator of severity and outcome on evaluating hemogram (CBC) values than the more commonly used leukocyte count