Prothrombin time and international normalized ratio predict bleeding complications among cardiac valve replacement patients undergoing cardiopulmonary bypass

Background: Hemorrhage after cardiopulmonary bypass (CPB) remains a clinical problem. Many risk factors associated with excessive blood loss have been identified, but postoperative bleeding remains poorly explained because of the complexity of the hemostatic process and the technical difficulties imposed by operative procedures. It suggests a need for patient testing to determinate hemostatic disorder after CPB and to be able differentiate a surgical cause for abnormal bleeding. Objectives: The study objective was to determine the prothrombin time (PT) and international normalized ratio (INR) in predicting bleeding in Sudanese patients among Mechanical valve replacement undergoing cardiopulmonary bypass. Design: Descriptive Cross sectional study Methodology: A prosthetic valve was implanted in 150 patients between July 2013 to January 2014.The age of patients ranged between 20 to 80 years with mean of 41years. The PT and INR were determined using coagulation analyzer model Spinreact- (BIOBAS10). One hundred and fifty patients underwent valve replacement: 60 patients(40%) had isolated mitral valve replacement (MVR), 46 patients(30.7%) had isolated aortic valve replacement (AVR), 26(17.3%) had duple valve replacement( DVR) and 18 (12%) had coronary artery bypass graft (CABG), and 50 healthy individuals were recruited as control group. Results: The mean of prothrombin time(PT) was (34.5±14.02) seconds and there was significant variation (p.value ˂ 0.05) between the patients and controls(13.1±1.8)seconds. The mean international normalized ratio(INR) was (3.2±1.6) however there was a significant variation (p.value ˂ 0.05) between the patients and controls(1.0±0.25). Among Sudanese patients with prosthetic heart valve, bleeding was the major complications rather than thromboemboloism. About 129(86%) patients from 150 had prothrombin time more than 20 seconds and about 44(29.3%) patients show international normalized ratio more than 3.5. The mean PT-INR was 2.4±0.6 in the cases without hemorrhage complications, and 4.2±1.5 in the patients associated with excessive bleeding. There was significant difference in mean PT-INR between the bleeding complication group and non complication group (p.value ˂ 0.05). More than 72% of patients with hemorrhage complications showed the PT-INR more than 3.97. Conclusion: PT and INR had high sensitivity and specificity in predicting blood loss among patients with valvular replacement and represent good indicators of platelet and fresh frozen plasma transfusion in these patients. The Prothrombin time and INR correlated with blood loss and transfusion requirements for predicting excessive blood loss after cardiopulmonary bypass.