Does the platelet function analyser (PFA-100) predict blood loss after cardiopulmonary bypass?

Abstract

This study was designed to determine if a new point-of-care test (PFA-100) platelet function analyser) that assesses platelet function predicts blood loss after cardiac surgery. and results. Blood samples from 70 patients were drawn before and after cardiopulmonary bypass (CPB) for PFA-100 measurements. The system consists of a cartridge in which a membrane and an aperture are coated with either collagen/adenosine-5'-diphosphate or collagen/epinephrine. The instrument determines the time required for full occlusion of the aperture (closure time). We observed a weak correlation between pre-CPB collagen/epinephrine closure time and second-hour mediastinal blood loss (r=0.34, P=0.01). The sensitivity and positive predictive value of the PFA-100 measurements were comparable to platelet count for predicting excessive bleeding after CPB (75 and 27% vs 100 and 25%, respectively). The PFA-100 is a logical test for detecting patients who could have excessive bleeding after CPB. However, the PFA-100 was not able to separate patients at low risk of subsequent bleeding from those who had substantial bleeding.