Platelet function in blood sampled through heart catheters

Platelet function was studied in blood sampled from the caval vein of 56 patients through various heart catheters. Reduced platelet retention was the most consistent finding while aggregation was not influenced by the sampling procedure. Polyurethane (Cordis and Positrol) catheters affected platelets less than catheters of woven dacron (Sones and Zucker). Sones catheters increased plasma beta-thromboglobulin levels slightly, and some platelets were trapped in the Zucker catheters. Much the same reduction in retention was induced by heparinized as by other catheters. Platelet retention values had a poorer reproducibility than the other platelet function parameters in samples collected at intervals of 45 min, while an acceptable correlation existed between parallel samples. The influence on platelets of blood sampled via polyurethane catheters was very moderate, and should allow the detection of alterations in platelet functions that occur in the circulation.