Reduction of platelet/fibrin deposition in haemodialysers by aspirin administration

Aspirin, a drug known to inhibit the platelet release reaction, was evaluated for its potential in reducing platelet/fibrin deposition in hollow fibre dialysers. Twelve patients with endstage renal failure were given the drug under controlled conditions while being treated by regular maintenance haemodialysis. After base-line data were collected during a mean number of 11.7 dialysers per study, observations were repeated for a mean of 9.3 dialysers, during which time each patient took 600 mg of aspirin by mouth every morning. Thrombus deposition, measured by volume loss of the blood compartment of the dialyser fibre bundle, was significantly reduced (P less than 0.05) during aspirin administration in six of the 12 studies. The mean volume loss of the fibre bundle in these six studies (responders) was 25% per dialysis during the control period, and 13% with aspirin; in the other six studies (non-responders), the mean values were 8% and 6% respectively. Aspirin prolonged the bleeding time in all patients, and significantly (p less than 0.05) impaired platelet aggregation in both responders and non-responders.