Coronary artery bypass grafting (CABG) is the most common cardiothoracic surgical procedure performed in the United States. The majority of patients undergoing CABG are placed on cardiopulmonary bypass (CPB) to support the circulation. CPB hemodilutes the patient imposing extremes in the hemostatic system, requiring careful assessment of pre-surgical hematologic values. Recent clinical data suggests that patients who receive blood transfusions while hospitalized for CABG have an increased morbidity and mortality. Women have a greater risk of transfusions than men with CABG and are thus at greater postoperative risk. The purpose of the present study was to determine the lowest safe hematocrit level achievable on CPB during CABG surgery where no transfusion and no post-operative complications were identified.
Methods: Inpatient record review evaluation including socio-demographic data, hematocrit values (pre-pump and on pump), red blood cell transfusion administration and Surgery, postoperative complications.
Results: Collected data from 136 first-time, single CABG patients demonstrated 68% had no postoperative complications. Of this non-complicated group 60% were transfused while only 40% were non-transfused. The non-complicated, non-transrusea group nematocrit vaiues averagea 25.1% +/- 2.8 with a minimum of 19%. (P = 0.003). 68% of the patients had no postoperative complication. Transient acute renal insufficiency was the most common complication observed.
Conclusion: The lowest safe hematocrit level on CABG in non-complicated and non-transfused patients was 19% corresponding to an average of 25.1% +/- 2.8. A preoperative patient profile has been identified where age, weight, height, BSA, BMI, and pre-pump and on pump hematocrit values can aid medical staff about transfusion decision making.