ACCURACY OF COAGULATION STUDIES PERFORMED ON BLOOD SAMPLES OBTAINED FROM ARTERIAL CANNULAE

Autor: W. Allardyce, B. Cowan, S. R. Haynes, P. Tansey
Rok vydání: 1992
Předmět:
Zdroj: British Journal of Anaesthesia. 69:599-601
ISSN: 0007-0912
DOI: 10.1093/bja/69.6.599
Popis: We have assessed the accuracy of coagulation studies in blood obtained from intra-arterial cannulae. Paired samples were studied in blood from 39 patients receiving intensive care; one sample was obtained by venepuncture and the other from an intra-arterial cannula after the apparatus deadspace plus 5 ml of blood had been discarded. Activated partial thromboplastin time (APTT) (with throm-boplastin routinely used in our laboratory), pro-thrombin time (PT), thrombin time (TT), fibrinogen and heparin assays were measured on each sample. In 37 sample pairs, APTT was measured also using a different thromboplastin. The median difference between the sample pairs was 5.5 s for APTT (P = 0.032) and 1.0 s (P = 0.048) for TT, the times for arterial cannula samples being longer. There was no significant difference between arterial cannula and venepuncture samples for PT or fibrinogen concentration. Heparin assays revealed heparin contamination in samples obtained from arterial can-nulae in 15 of 30 patients not receiving heparin. It is concluded that, when coagulation studies are performed using the techniques used routinely in our laboratory, a blood sample from an arterial cannula may give clinically misleading information because of contamination with small amounts of heparin, and that separate venepuncture is recommended.
Databáze: OpenAIRE