There are currently no scoring tools validated for use in predicting heparin-induced thrombocytopenia in patients receiving extracorporeal membrane oxygenation. This study aims to determine the predictive value of the Warkentin 4T score, Lilo-Le Louet score, and the heparin-induced thrombocytopenia expert probability score in detecting heparin-induced thrombocytopenia in patients on extracorporeal membrane oxygenation. This was a single center, retrospective, observational cohort study of patients at Rush University Medical Center. Heparin-induced thrombocytopenia–positive patients were defined as those with an optical density greater than or equal to 0.4, consistent with a positive anti-platelet 4 heparin antibody. Out of 39 patients on extracorporeal membrane oxygenation with suspected heparin-induced thrombocytopenia, six (15.4%) were found to be anti-platelet 4–positive. A heparin-induced thrombocytopenia diagnosis was confirmed by serotonin-release assay in two patients (5.1%). The 4T, heparin-induced thrombocytopenia expert probability, and Lilo-Le Louet scoring tools all demonstrated a low positive predictive value (21.4%, 16.7%, and 6.7%, respectively), with the 4T and heparin-induced thrombocytopenia expert probability scores demonstrating the highest specificity (66.7% and 84.8%, respectively) and lowest sensitivity (50% and 16.7%, respectively). The Lilo-Le Louet score had high sensitivity (100%) and low specificity (12.5%) in post-cardiopulmonary bypass patients. Based on the findings of this study, all three scoring tools have limited utility for predicting heparin-induced thrombocytopenia in patients on extracorporeal membrane oxygenation.

Background: The differential diagnosis for thrombocytopenia in critical illness is often extensive. This study was performed to determine the incidence of thrombocytopenia in septic patients undergoing continuous renal replacement therapy (CRRT) versus those not undergoing CRRT. Objective: The primary outcome of this study was to compare the development of thrombocytopenia, defined as a platelet count ≤ 100 × 103/mm3, in septic patients within 5 days of time zero. Time zero was defined as the baseline platelet count upon hospital admission or CRRT initiation. Methods: An IRB approved, retrospective cohort study was conducted evaluating thrombocytopenia development in critically ill, septic patients who were initiated on CRRT versus those whom were not. Baseline and clinical characteristics were displayed using descriptive statistics. The primary outcome was evaluated overall and in subgroups of CRRT using Chi-square tests. Results: One hundred sixty patients, 80 per arm, were included in the study. Thrombocytopenia development within 5 days occurred more frequently in the renal replacement therapy (RRT) group compared to the control group (67.5% vs. 6.3%, p < 0.001). In the subgroup analysis of the RRT cohort, thrombocytopenia development within 5 days occurred more frequently in the continuous veno-venous hemofiltration (CVVH) group compared to the accelerated veno-venous hemofiltration (AVVH) group (76% vs. 53.3%, p = 0.049). Conclusion: There is a high likelihood that septic patients initiated on CRRT will develop thrombocytopenia during their hospital stay. Patients receiving CVVH may develop thrombocytopenia more frequently than those receiving AVVH. Overall, CRRT should remain a differential diagnosis for thrombocytopenia development in this patient population.