[The effect of platelet transfusion on traumatic intracranial hemorrhage among patients treated with aspirin].

Background: Head trauma represents a serious medical and socio-economical problem owing to its related morbidity and mortality. One of its serious complications is traumatic intracranial hemorrhage (TICH). There is evidence that TICH has a tendency to expand, especially during the first hours following injury. Aspirin has a central role in preventing thromboembolic complications in atherosclerotic conditions. This effect is mediated through the inhibition of platelet activity. There is a theoretical concern that treatment prior to the head injury with aspirin may expand the size of TICH. The purpose of the current study was to evaluate the effect of platelet transfusion on the extent of TICH expansion among patients treated with aspirin.

Methods: This retrospective study includes patients admitted to the Tel-Aviv Medical Center and the Tel-Hashomer Medical Center between 1/12/2004 and 31/10/2008. Patients were included if they underwent closed head injury, were treated regularly with aspirin prior to the injury, and had radiological evidence of an intraparenchymal hemorrhage or contusion (IPHC) or an acute subdural hematoma (ASDH]. The interval between the injury and the first computed tomography [CT] scan was not longer than 12 hours, and the interval between the first CT scan and the control CT scan was not longer than 24 hours. The effect of platelet transfusion administered between these two CT scans on the radiological and clinical outcomes was evaluated by a comparison between a group of patients treated with platelet transfusion (group A) and a group of patients who weren't treated with it (group B).

Results: A total of 44 patients were included in the study: 14 patients had IPHC, 40 had ASDH and 10 had both IPHC and ASDH. In the IPHC group the frequency of hemorrhagic expansion and the extent of expansion were greater in group A than in group B. Possibly, an earlier first CT, longer duration between both CT scans and a larger hemorrhage volume on CT1 in group A may explain these differences. In the ASDH group the frequency of hemorrhagic expansion was lower in group A than in group B, but without statistical significance. There was no significant difference in the extent of hemorrhagic expansion between the two treatment groups.

Conclusions: From this study it appears that platelet transfusion within 36 hours post injury for patients with TICH who were treated with aspirin prior to the head injury does not reduce the rate or extent of hemorrhagic expansion. However, owing to the limitations of the present study, this conclusion should be considered with caution. We recommend evaluating this issue in a prospective, randomized, multi-center study.