Effect of Time and Haemolysis on Prothrombin Time (PT) and Activated Partial Thromboplastin Time (APTT) Measurement on Blood Samples

Background: Coagulation, also known as blood clotting, is the process by which blood convert from a liquid to a gel, forming a blood clot. It referred to haemostasis, the stopping of blood loss from a damaged vessel, followed by repair. Material and methods: This was cross sectional study conducted at the albawasla medical laboratory, Khartoum, Sudan during the period August to November, 2021 and to evaluate the effect of time and hemolysis on prothrombin time and activated partial thromboplastin time tests. 50 samples (case group) were collected from the patients attending police teaching hospital   and requested to the PT and APTT test in addition to that,50 apparently healthy donors with no history of any coagulation problems or any chronic disease were selected as control group. Three ml of venous blood samples were collected in container with Tri Sodium Citrate anticoagulant. The coagulation tests (PT and APTT) were performed using semiautomatic device (coagulometer machine MI). Results:  The result of this study revealed that; when compared the measurement of PT and APTT immediately and after one hour there was insignificant differences (p. v.>0.05).  also when compared the measurement of PT and APTT between hemolyzed and non-hemolyzed samples there was significant differences ( p. v. 0.05).  For the correlation there was significant correlation in the case group for the PT and APTT immediately, after one hour, and hemolyzed samples. Conclusion: In the cases group results showed insignificant differences in the results of PT and APTT between immediate sample and after 1 hour in and significant differences in the results of PT and APTT between hemolyzed and non-hemolyzed samples, also there was insignificant differences between age and gender, immediately, after one hr. and hemolyzed sample in PT and APTT. Keywords:  Homeostasis,  hemolyzed  sample, PT and APTT