Predictors of post operative bleeding and blood transfusion in cardiac surgery.

Introduction: In spite of the recent advances in heart surgery, patients undergoing cardiac surgery with cardiopulmonary bypass are at risk of developing significant post-operative bleeding and substantial blood requirements.

Objective: To evaluate the impact of some perioperative predictors of post-operative bleeding, and blood transfusion after heart surgery and offer suggestions on preventive measures.

Design And Methods: A prospective analytical study. The perioperative factors studied were haemoglobin level, international normalised ratio (INR), platelet count, and total bypass time. Eighty-seven consecutive patients who underwent heart surgery in the year 2004 were selected. Each patient had laboratory work up which included full blood count, clotting profile, kidney and liver function tests. The total blood loss within the first twenty-four hours and the total units of blood transfused before the patient was discharged were also recorded.

Results: Pre-operative haemoglobin was significant in determining the total units of blood received by a patient. Increasing total bypass time caused a significant increase in the percentage reduction of the pre-operative platelet count (p <0.004). However even though there was an increasing trend of post-operative bleeding with increase in total bypass time, this was not significant from the analysis (p<0.069). The percentage reduction in platelet count and immediate postoperative platelet count were significant predictors of postoperative bleeding (p <0 .009) and (p <0.003) respectively.

Conclusion: Pre-operative haemoglobin, percentage reduction in the platelet count after cardiopulmonary bypass and immediate postoperative platelet count are significant predictors of postoperative bleeding and blood requirements.