Effect of Heparin on Coagulation Tests: A Comparison of Continuous and Bolus Infusion in Haemodialysis Patients

Abstract

Introduction: Haemodialysis is one of the most conventional treatments of chronic renal failure. The risk of clot formation is high during haemodialysis due to regular contact of blood with the surfaces of foreign objects such as catheters, dialyzers’ membrane, and other materials used for dialysis. Therefore, to prevent clot formation during haemodialysis, the dialysis system requires anticoagulation; this is usually done by heparin. Aim: The present study aimed to compare two heparinization methods and determine the proper impacts of these methods. Materials and Methods: In this quasi-experimental study, 80 haemodialysis patients covered by the dialysis center of Amir-al-momenin Hospital of Zabol were studied in two 40-member groups of heparin therapy methods of bolus injection and continuous infusion. PT and PTT were measured in blood samples collected from all patients before starting haemodialysis. The first group received 3000 units of heparin once the haemodialysis machine started to work and 2000 units of heparin two hours later as bolus injection. In the second group, 1500 units of heparin was injected at the start of dialysis after then, 5000 units of heparin (one mL) were mixed with 11 mL of distilled water and infused using a heparin injection pump up to half an hour before the end of dialysis. At 30 minutes after starting dialysis and at the end of 4 hours of haemodialysis, PT and PTT were measured and compared between the two groups. Results: According to the results, the mean partial thromboplastin time in the bolus and continuous heparin-receiving group was 41.75±6.29 and 37.90±4.77, respectively, which was statistically significant (p=0.036). But PT was 14.45±1.82 in the bolus heparin group and 13.95±1.39 in the continuous heparin group, which was not significant according to the results of independent t-test (p=0.336). Conclusion: The results indicated a statistically significant difference between the bolus heparin injection and the continuous heparin infusion groups in terms of coagulation tests in haemodialysis patients (p=0.036). Therefore, given the effects of heparin on coagulation, it was more effective in the bolus heparin group than the continuous infusion group. It is recommended to use the bolus method for heparin therapy during haemodialysis.

Keywords

• continuous heparin infusion
• heparin bolus injection
• pt
• ptt