Published in:
Open Access 01-12-2018 | Editorial
Thrombocytopenia in the ICU: disseminated intravascular coagulation and thrombotic microangiopathies—what intensivists need to know
Published in: Critical Care | Issue 1/2018
Login to get accessExcerpt
Thrombocytopenia affects 25–55% of intensive care unit (ICU) patients [1]. The reasons for thrombocytopenia in the ICU are numerous, including, among others, sepsis, drugs, and the use of extracorporeal devices (Fig. 1) [1]. Some patients with thrombocytopenia also have microangiopathic hemolytic anemia (MAHA), accompanied by elevated serum lactate dehydrogenase levels and schistocytes on the blood film [2, 3]. This combination of thrombocytopenia and MAHA, in which thrombi form in the microvasculature and schistocytes develop from red cell destruction as they pass over these thrombi [2], occurs in patients with disseminated intravascular coagulation (DIC), but also in those with thrombotic microangiopathies (TMAs), including thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS).
Fig. 1
An algorithm to rapidly differentiate disseminated intravascular coagulation (DIC) from thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS) in the intensive care unit (ICU). Thrombocytopenia with microangiopathic hemolytic anemia (MAHA), negative Coombs test, elevated lactate dehydrogenase (LDH), and organ dysfunction are common to DIC, TTP, and HUS. Abnormal coagulation studies, including prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen concentration, fibrin degradation products, D-dimers, and antithrombin, are required for differentiation of DIC from thrombotic microangiopathies (TMAs). Additionally, blood pressure should be considered because HUS usually presents with hypertension. Once DIC has been excluded, the underlying TMA must be identified. TTP is diagnosed by identification of low ADAMTS13 activity (< 5-10%) and treated urgently with plasma exchange initially; HUS is associated with normal ADAMTS13 activity (> 5–10%) and the type of HUS elucidated by performing a Shiga-toxin producing Escherichia coli (STEC) stool culture or polymerase chain reaction (PCR) assay. Positive STEC strongly suggests STEC-HUS; negative STEC strongly suggests aHUS, with or without an associated complement-activating condition (e.g., infection, malignant hypertension, the post-partum period, kidney transplantation, drugs, or malignancy). Rapid detection and management of any associated complement-activating condition and consideration of eculizumab are required [3, 6, 9, 13]
× ![]()
…