Premium
The order of draw: much ado about nothing?
Author(s) -
Indevuyst C.,
Schuermans W.,
Bailleul E.,
Meeus P.
Publication year - 2015
Publication title -
international journal of laboratory hematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.705
H-Index - 55
eISSN - 1751-553X
pISSN - 1751-5521
DOI - 10.1111/ijlh.12230
Subject(s) - partial thromboplastin time , tube (container) , heparin , prothrombin time , medicine , thromboplastin , chemistry , anesthesia , surgery , materials science , platelet , coagulation , composite material
Summary Introduction The ‘order of draw’ has been advocated since 1982 to reduce the risk of cross‐contaminating blood tubes with additives from a previously filled tube. Methods We studied 193 patients receiving oral anticoagulation. Multiple tubes were collected in a specific order using the Sarstedt Safety Monovette System. We evaluated the effect of the ‘order of draw’ on the prothrombin time/international normalized ratio (PT/INR) and the activated partial thromboplastin time (APTT) when the citrate tube is drawn as the first tube, second tube or after a heparin, EDTA or serum tube with clot activator. Results There was no statistically significant influence on the PT/INR. The same applies for the APTT measured on a citrate tube drawn after a heparin tube. There was a small, but statistically significant bias on the APTT when the citrate tube was drawn as the first tube, after an EDTA tube or after a serum tube with clot activator. We consider this bias (max. 0.2 s) as not clinically significant. Conclusion The order of draw has no significant influence on the PT/INR and APTT when measured on a Sarstedt citrate tube filled without the use of a discard tube or after a heparin, EDTA or serum tube with clot activator.