4 Discussion
After coronary bypass (CABG) operations became routine procedures in many centers, various scientific studies were conducted on each phase of CABG operations. We now know that postoperative bleeding is a serious cause of mortality and morbidity19,20,21. Bleeding may cause end organ damage due to low perfusion, which may lead to increased intensive care stay and hospital costs, cerebrovascular events, renal failure, mesentery ischemia, liver damage and ultimately, mortality19,20,21. Therefore, postoperative bleeding is one of the nightmares of surgeons. Blood product transfusion, performed to avoid these complications caused by hypovolemia and low oxygen supply, is a risky procedure itself. Studies have shown that febrile reactions, renal dysfunction, respiratory distress, immunosuppression, infections, and even low cardiac output can occur after blood product transfusion22,23.  Our aim in this study was not to re-prove all this information, but by including only diabetic patients treated with CABG, to predict more clearly the risk of bleeding in the early period in a limited patient population. The progression of massive bleeding is clear. The reason we included only diabetic patients in our study is that diabetes is one of the biggest vascular damage predictors 24, its association with atherosclerotic heart disease is high25, and cardiovascular disease is the cause of mortality in approximately 75% of diabetic patients 26.
The mean BMI values of patients in the E-CABG Group 2-3 is lower than those in Group 1-2. In PAPWORTH risk scoring, low BMI is a risk factor for postoperative bleeding 11. Frankly, we could not find the mechanism explaining the relationship between BMI and bleeding in our literature review. However, BMI is calculated as kg/mORS’ as a risk parameter.
1,3. It can be suggested that patients with normal preoperative hemogram (or hematocrit) values will need less transfusion in the postoperative period. The number of platelets, which are the basic elements of the coagulation system, and their functional capacity, are also effective on postoperative bleeding 27,28,29
Our study included on-pump CABG patients. It is a known fact that the heart-lung machine causes end organ damage 30 due to changes in microcirculation and blood pressure, as well as microthrombi31,3233 RS list. Among the bleeding scores, only Will-Bleed and Trust scores examine kidney functions. We believe this to be deficiency of Papworth and Track.
There may be differences between genders in terms of clinical course and diseases. In the evaluation of postoperative bleeding, the female gender was at higher risk 34,35
In our study, age, hypertension, pulmonary hypertension, COPD, and peripheral vascular diseases were not associated with postoperative bleeding. Interestingly, no significant results were obtained in terms of the tendency to bleed postoperatively in patients who were taken to emergency surgery. Antiplatelet agents are one of the main therapeutic agents in coronary artery diseases 36. While discontinuation of acetylsalicylic acid (ASA) before the operation is not recommended, clopidogrel and the less frequently used ticagrelor should be discontinued at least 5 days before the operation 36. Patients receiving ticagrelor were not included in the study. However, those using clopidogrel and ASA were not evaluated in separate groups. This can be considered the biggest limitation of our study. We can attribute the lack of statistically significant bleeding in patients undergoing emergency surgery to two reasons: The fact that the number of patients using clopidogrel and undergoing emergency operation is lower than those using ASA, and patients undergoing emergency surgery have recently been diagnosed with CAD and therefore have not received antiplatelet therapy before the operation. Ultimately, as clearly shown in the guidelines, the amount of postoperative bleeding may vary depending on the type of antiplatelet agent, and this is a proven fact that cannot be ignored for the timing of the operation 36. Therefore, preoperative use of antiplatelets will be included in our ORS, which we plan to present with larger case numbers in the future.