PT/INR is used to monitor AVK therapy (Warfarin). There are different thromboplastin reagents and methods used to assess prothrombin status of extrinsic pathway. The main aim of this study is to determine the accuracy of manufactured thromboplastin in comparison to standard thromboplastin. The study is laboratory based cross sectional study in which Thirty-six laboratories in Khartoum state were evaluated for the performance of PT & INR technique by using certified lyophilized plasma level 1. Data were collected through direct interview done by researcher in which questionnaire was filled and sample were tested in duplicate two different types of thromboplastin one which is used by the laboratories (manufactured thrmboplastin) and the other by standard throboplastin. Data was analyzed by using statistical equation and SPSS. Study shows there were different reagents to measure PT/INR fortress occupy (50%) of them and 8.3% for each one from Spectrum, uniplastin, pioplastin, Tetlclot, Neoplastin, Vitro, Biomed, Spinereact, Tico and Technoplastin. with Different methods as manual 2(5.56%), semi automation 28(77.78%) and full automation 1(2.78%). Coagulometers were 15(41.67%) bio-bas (Spinreact) magnetic and O.D 6(16.67%). 21(58.3%) of laboratories were calibrate pipette. Controls use were 20(55.56%) commercial and 14(38.89%) sample. study were found the CV 0.35, SD ±1.12 and Mean 1.43 of samples and CV 0.78, SD ±1.13 and Mean 3.2 of standards. 14(39%) were correct it with new derived ISI when calculate INR. Conclusion: There are varies reagents used by different laboratories. majority of labs using semiautomated methods and only 2% using automation .Inconsistency in the accuracy of the result and different mean ,CV and SD between commercial reagent and the control one.
Keywords PT, INR, AVK, Thromboplastin, lyophilized, semiauttomated and Khartoum.
Abbreviations PT: Prothrombin tim INR: International Normalized Ratio AVK: Anti vitamin K O.D: Optical Density SD: Stander Deviation CV: Coefficient of Variation