The application of point-of-care platelet function assay in guiding platelet transfusion in aspirin-users with intracranial haemorrhages

Abstract

BackgroundAn increasing number of patients with intracranial haemorrhages are aspirin-users. Neurosurgeons commonly attempt to minimize the risk of re-bleeding by withholding the medication and giving platelet transfusion. However, recent studies raised safety concerns and showed poorer outcome with platelet transfusion when the latter was not guided by changes in platelet function. Aim of studyTo study the temporal pattern and degree of changes in platelet activities following a fixed dose of platelet transfusion in aspirin-users with intracranial haemorrhages. MethodsAspirin-users with intracranial haemorrhages underwent baseline aspirin response units (ARU) using the VerifyNow® assay. Those who showed abnormal platelet activity received a single dose of 4 units of platelet concentrate. ARU were then repeated at 4 h, 24 h and 48 h post-transfusion. Patients were classified according to their responses to transfusion. ResultsTwenty patients were recruited. At 4 h after transfusion, 11 (55%) patients had normalised platelet activities while the rest may show delayed or absent of normalization. Overall, eight (40%) patients were ‘early and persistent transfusion responders’, five ‘delayed transfusion responders’, and five (25%) had persistently abnormal platelet function. Two (10%) patients who initially responded to transfusion failed to maintain normalized platelet activity. ConclusionPlatelet activities in aspirin-users showed considerable heterogeneity up to 48 h following a blanket approach of platelet transfusion. The need for repeated transfusion or alternative therapy strongly argues for a guided practice for transfusion based on point-of-care platelet function assay. Future research should also adopt this approach to re-examine the safety and effectiveness of platelet transfusion in these patients.