Incidence of Thrombocytopenia in Patients Undergoing Continuous and Prolonged Intermittent Renal Replacement Therapy

Background: Thrombocytopenia is commonly noted in critically ill patients resulting from various etiologies, including but not limited to sepsis, shock, or medications. Critically ill patients receiving renal replacement therapy (RRT) may be on concomitant heparin, raising suspicion for heparin-induced thrombocytopenia (HIT). However, literature suggests that thrombocytopenia may occur due to continuous renal replacement therapy (CRRT) itself. The primary objective of this study is to evaluate the incidence of thrombocytopenia in patients receiving both continuous renal replacement therapy and prolonged intermittent renal replacement therapy (PIRRT). Methods: This retrospective observational analysis aimed to evaluate thrombocytopenia in patients receiving CRRT, PIRRT, or both in a single admission. Data was gathered from patients receiving extended RRT while admitted to a single institution from November 2021 to October 2023. The primary outcome was incidence of thrombocytopenia after initiating extended RRT, as defined by a reduction in platelet count to less than 150 × 109/L in a previously nonthrombocytopenic patient. Results: Of the patients included in this study undergoing extended RRT, 32/51 (62.8%) experienced thrombocytopenia either during RRT or within 24 hours of RRT completion. The mean baseline platelet count was 250.7 × 109/L and the mean percent change in platelet count was a decrease of 43.5%. Conclusion: CRRT and PIRRT were associated with a high incidence of new onset thrombocytopenia in patients admitted to the ICU.