Summary
Point-of-care (POC) monitoring of oral anticoagulation has been widely adopted in
both paediatric and adult patients. A new POC system, the CoaguChek XS® has recently been developed to measure the international normalised ratio (INR) and
may offer significant advantages. The CoaguChek XS® utilises a new method of electrochemical clot detection based on thrombin generation.
This system has not been previously evaluated in children with reference to the laboratory
gold standard, the prothrombin time using reference thromboplastin. It was the objective
to compare values obtained by the CoaguChek XS® system with both the venous INR and the gold standard for anticoagulant monitoring,
prothrombin time with reference thromboplastin (rTF/95).To evaluate the impact of
testing using the Coagu-Chek XS® on clinical anticoagulant dosing decisions. Fifty paired venous INR and capillary
CoaguChek XS® results were obtained from 31 children (aged up to 16 years).The laboratory gold
standard, a manual prothrombin time with reference thromboplastin (rTF/95) was additionally
performed on 26 samples. Correlation between the CoaguChek XS® result and the venous INR was r= 0.810. Agreement between the CoaguChek XS result
and the reference INR was shown to be higher (r=0.95), in the subset analysed by this
method. Correlation between the venous INR and reference INR was r=0.90. Despite changes
to the methodology of testing with the CoaguChek XS® POC monitoring system, the accuracy of this method when compared with both the venous
INR and gold standard reference INR was satisfactory. This resulted in infrequent
changes to clinical decision making regarding anticoagulation
Keywords
Children - CoaguChek XS
®
- point of care - reference thromboplastin - venous INR - warfarin