Prevalence, Risk Factors, Characteristics, and Clinical Outcomes of Thrombocytopenia in the Intensive Care Unit: A Prospective Single‐Center Cohort Study

Background Thrombocytopenia is a common hematologic abnormality in the intensive care unit (ICU), affecting approximately 50% of patients. It is associated with increased mortality and bleeding risk. Despite its clinical significance, epidemiological studies on ICU‐related thrombocytopenia in Gulf Cooperation Council countries remain limited. Methods This prospective observational cohort study was conducted to investigate the prevalence, risk factors, characteristics, and clinical outcomes of thrombocytopenia in the ICU. We included ICU patients admitted for ≥ 24 h, excluding pregnant women and individuals under 18. Thrombocytopenia was defined as a platelet count < 150 × 10 9 /L after ruling out pseudothrombocytopenia. Patients were stratified by thrombocytopenia severity and followed until discharge, death, or 30 days post onset. Risk factors were analyzed using multivariable modified Poisson regression models. The Naranjo probability scale and the 4Ts score were used for causal assessment of drug‐induced thrombocytopenia (DIT) and heparin‐induced thrombocytopenia (HIT). Primary outcomes included three‐month ICU mortality and major bleeding. Kaplan–Meier with log‐rank tests assessed time‐to‐mortality. Results The study enrolled 276 patients; 38.8% had thrombocytopenia, including 23.4% with severe thrombocytopenia. The incidence of new‐onset thrombocytopenia was 22.5%. DIT was suspected in 15% of cases, including five patients with potential HIT. Shock diagnosis was a significant predictor of new‐onset thrombocytopenia (adjusted risk ratio = 2.26, 95% confidence interval: 1.35–3.79). Thrombocytopenic patients had higher Acute Physiology and Chronic Health Evaluation (APACHE) IV scores ( p < 0.001) and experienced more major bleeding events (16.8% vs. 8.3%, p = 0.03) and higher mortality rates (27.1% vs. 5.3%, p < 0.001) with reduced time‐to‐mortality (log‐rank p = 0.01). New‐onset thrombocytopenia was independently associated with major bleeding and mortality. Conclusion Thrombocytopenia is prevalent in the ICU, correlating to disease severity, major bleeding, and mortality. The study’s findings underscore the need for timely recognition and effective management of thrombocytopenia to improve patient outcomes.