Platelet transfusion in critical care: A new method to analyze transfusion practice based on decision time intervals

While prior studies of platelet transfusion in critical care have focused on transfusions given, proper analysis of clinical transfusion practice also requires consideration of the decision not to transfuse.

We introduce a new method to assess transfusion practice based on decision time intervals (DTIs). Each patient's intensive care (ICU) stay was segmented into a series of DTIs defined by a time interval following results of a complete blood count (CBC). We studied the presence of 17 clinical factors during each DTI whether transfusion was given or not. We used a generalized linear mixed model to assess the most influential clinical triggers for platelet transfusion.

Among 6125 ICU patients treated between October 2016 and October 2021, we analyzed 39,745 DTIs among patients (n = 2921) who had at least one DTI with thrombocytopenia (≤150,000/μL). We found no association between platelet count and two markers of bleeding: drop in hemoglobin and chest tube drainage. We found that the majority of DTIs were associated with no platelet transfusion regardless of the platelet count; that no specific platelet value triggered transfusion; but rather that multiple clinical factors in conjunction with the platelet count influenced the decision to transfuse.

DTI analysis represents a new method to assess transfusion practice that considers both transfusions given and not given, and that analyzes clinical circumstances present when decisions regarding transfusion are made. The method is easily adapted to blood components other than platelet transfusions and is easily extended to other ICU and other hospital settings.