Prospective randomized evaluation of two methods of drawing coagulation studies from heparinized arterial lines

To establish a standardized protocol of obtaining coagulation studies from arterial lines without heparin contamination, two methods were evaluated in a prospective randomized fashion for accuracy by comparing PT and aPTT results with simultaneous samples drawn by venipuncture. Fifty paired samples were obtained, 25 by method A and 25 by method B, from critically ill patients in the surgical intensive care unit at City of Memphis Hospital. Analyses of PT and aPTT from these samples revealed a close statistical correlation with the venous controls and no clinically significant difference between the samples.