RT Book, Section A1 Chapin, John C. A1 Desancho, Maria T. A2 Oropello, John M. A2 Pastores, Stephen M. A2 Kvetan, Vladimir SR Print(0) ID 1136414845 T1 Hematologic Dysfunction in the ICU T2 Critical Care YR 1 FD 1 PB McGraw-Hill Education PP New York, NY SN 9780071820813 LK accessmedicine.mhmedical.com/content.aspx?aid=1136414845 RD 2024/11/13 AB KEY POINTSThe most common reasons for hematologic consultation in critically ill patients include thrombocytopenia, anemia, and less commonly, evaluation of leukocytosis and thrombocytosis.Coagulopathies including severe bleeding and thrombotic disorders are very prevalent in intensive care unit (ICU) patients due to their underlying conditions including liver dysfunction and acquired vitamin K deficiency. Bleeding can occur due to renal insufficiency and the use of antiplatelet agents and anticoagulant therapy.Inflammation occurs in sepsis, systemic inflammatory response syndrome, and other critical illnesses, and causes alterations in both hemostasis and fibrinolysis.Disseminated intravascular coagulation (DIC) is observed in approximately 50% of patients with sepsis, and is an independent predictor of morbidity and mortality.Thrombocytopenia (platelet count < 150,000/L) occurs in 15% to 58% of ICU patients and may be due to medications, infections, DIC, thrombotic microangiopathies (thrombotic thrombocytopenic purpura [TTP] and atypical hemolytic uremic syndrome), heparin-induced thrombocytopenia (HIT), catastrophic antiphospholipid syndrome, and immune thrombocytopenic purpura.HIT is a clinicopathologic diagnosis that occurs in 1% to 4% of patients on unfractionated heparin (UFH), and less than 1% of patients on low-molecular-weight heparin (LMWH). It is more common in postsurgical patients than medical inpatients and in females.Prompt interaction between the intensivist and the hematologist is key to optimize the care of critically ill patients with hematologic dysfunction.