Thrombocytopenia in the Intensive Care Unit—Diagnostic Approach and Management

Thrombocytopenia often complicates critical illness and is associated with increased morbidity and mortality. Approaching thrombocytopenia is challenging in the intensive care unit (ICU) because of the multifactorial pathogenesis of this disorder. Interpretation of the platelet count course after ICU admission is helpful to narrow down the cause of thrombocytopenia. Whereas a moderate decrease within the first 3 days is rather typical in severely ill patients, an absent or blunted platelet count increase after 5 days indicates continuing critical illness and a worse outcome. A rapid decrease in platelet counts of more than 50% within 1–2 days, especially if occurring after an intermittent rise, requires immediate attention as it may be a symptom of immune-mediated mechanisms, eg, heparin-induced thrombocytopenia. Treatment should target the underlying disease. Platelet transfusions are indicated in bleeding patients, while there is no strong evidence supporting the usefulness of prophylactic transfusions in ICU patients.