Platelet Receptor Activity for Predicting Survival in Patients with Intracranial Bleeding

Abstract

Blood coagulation disorders in patients with intracranial bleeding as a result of head injuries or ruptured aneurysms are a diagnostic and therapeutic problem and appropriate assessments are needed to limit CNS damage and to implement preventive measures. The aim of the study was to monitor changes in platelet aggregation and to assess the importance of platelet dysfunction for predicting survival. Platelet receptor function analysis was performed using the agonists arachidonic acid (ASPI), adenosine diphosphate (ADP), collagen (COL), thrombin receptor activating protein (TRAP), ristocetin (RISTO) upon admission to the ICU and on days 2, 3, and 5. On admission, the ASPI, ADP, COL, TRAP, and RISTO tests indicated there was reduced platelet aggregation, despite there being a normal platelet count. In 'Non-survivors', the platelet response to all agonists was suppressed throughout the study period, while in 'Survivors' it improved. Measuring platelet function in ICU patients with intracranial bleeding is a strong predictor related to outcome: patients with impaired platelet aggregation had a lower 28-day survival rate compared to patients with normal platelet aggregation (log-rank test p = 0.014). The results indicated that measuring platelet aggregation can be helpful in the early detection, diagnosis, and treatment of bleeding disorders.

Keywords: aneurysm; craniocerebral trauma; intracranial hemorrhages; platelet aggregation; platelet function tests; ruptured; survival rate.

Figure 1

Flow diagram of the study. ICU, intensive care unit.

Figure 2

A comparison of the changes in platelet receptor activity between Survivors and Non-survivors in the following days of observation. A dotted line represents the lower reference range and the reference ranges for each test are as follows: ADP-test 534–1220 AU/min, TRAP-test 941–1536 AU/min, RISTO-test 896–2013 AU/min, ASPI-test 745–1361 AU/min, COL-test 459–1166 AU/min. The p-value represents statistically significant differences between the study groups. The box plots represent the median values (middle line) with upper and lower quartiles (box); the whiskers represent the minimum and maximum values.

Figure 3

Probability of 28-day survival (Kaplan–Meier curve, log-rank test). Patients with platelet aggregation disturbances on the first day of ICU treatment are indicated by a dotted line and patients without aggregation disturbances by a solid line.