PT  - JOURNAL ARTICLE
AU  - L Poller
AU  - M Keown
AU  - N Chauhan
AU  - A M H P van den Besselaar
AU  - A Tripodi
AU  - C Shiach
AU  - J Jespersen
TI  - European Concerted Action on Anticoagulation (ECAA). An assessment of lyophilised plasmas for ISI calibration of CoaguChek and TAS whole blood prothrombin time monitors
AID  - 10.1136/jcp.56.2.114
DP  - 2003 Feb 01
TA  - Journal of Clinical Pathology
PG  - 114--119
VI  - 56
IP  - 2
4099  - http://jcp.bmj.com/content/56/2/114.short
4100  - http://jcp.bmj.com/content/56/2/114.full
SO  - J Clin Pathol2003 Feb 01; 56
AB  - Aims: The recommended method for the international sensitivity index (ISI) calibration of whole blood point of care testing (POCT) prothrombin time (PT) systems was originally described by Tripodi et al in 1993 but is too complex and demanding. The present European Concerted Action on Anticoagulation (ECAA) study aimed to assess the reliability of simpler ISI calibration using lyophilised plasma samples. Methods: ISI calibrations using three different types of ECAA lyophilised plasma samples (artificially depleted, individual, and pooled coumarin) were compared with whole blood calibrations on CoaguChek Mini and TAS PT-NC POCT monitors at 10 centres. Results: With CoaguChek Mini systems, lyophilised coumarin plasma samples (both single donation and pooled) gave ISI and international normalised ratio (INR) values comparable to whole blood. With artificially depleted plasma, ISI and INR values were too high. With TAS PT-NC systems, all three types of lyophilised plasma samples gave inaccurate ISI and unreliable INR results, similar to previous ECAA findings with fresh plasma calibrations. Conclusions: With CoaguChek Mini systems, ISI calibration can be simplified by the use of ECAA lyophilised plasma samples from coumarin treated patients. Further study is needed to devise a simpler calibration method for the TAS PT-NC system.