Background: Cardiac surgery with cardiopulmonary bypass is grown rapidly in last years. The application of cardiopulmonary bypass using a heart-lung machine to perform open heart surgery is known to be associated with numerous pathophysiologic changes including injury of cellular components as erythrocyte, platelets, coagulopathy, and fibrinolysis. Objectives: Our study objective is to study on relation of open heart surgery phases and blood coagulation parameters. Materials and Methods: Blood samples from 49 patients (28 females and 21 males, aged 18- 63 years) who underwent open heart surgery with cardiopulnonary bypass (CPB) were collected before and at several time points during, after surgery and analyzed for coagulation parameters at Shastin Third Central Hospital. Results: To compare long continued cardiopulmonary bypass (over 1 h) surgery with less 1 h groups there prothrombin time was found 18.8±5.9 sec, international normalized ratio (INR) 2.09±0.9 sec prolonged (p<0.001) in 7 days after surgery. All coagulation parameters were decreased significantly (p<0.001) in during extracorporeal circulation and after 1 h declamping than preoperative level and reached near normal value in 48 h after surgery. Our results have referred to platelet counts reduction to about 53% in during surgery, 46.8% in 48 h after surgery of the preoperative level 237.4±57.1 with final return to normal levels 228.9±78.6 within 7 days. Conclusions
1. The cardiopulmonary bypass time and patient age in relation to open heart surgery type there were significant difference (p <0.01).
2. The coagulation parameters have revealed significant changes (p <0.01) in relation cardiopulmonary bypass time.
3. All coagulation parameters were decreased significantly (p<0.001) in during extracorporeal circulation and after 1 h decamping than preoperative level and reached near normal value in 48 h after surgery.
4. There was direct and less correlation between platelet level and CPB time (r=0.37, p<0.001).