Effects of Conventional Ultrafiltration During Cardiopulmonary Bypass on Serum Lactatemia in Patients Undergoing Cardiac Surgery

Abstract

Background: Cardiopulmonary bypass (CPB) is a crucial technique in cardiac surgeries to maintain systemic circulation and oxygenation. However, it can cause physiological changes like fluid overload, hemodilution, inflammatory response, and metabolic abnormalities. Monitoring serum lactate levels is essential for peri-operative management and patient outcomes. Conventional ultrafiltration (CUF) is utilized to reduce fluids, but understanding its impact on lactatemia is crucial.

Aim: To study the effects of conventional ultrafiltration throughout CPB on serum lactatemia in patients partaking cardiac surgery.

Methods: The study was a retrospective single-center study done at Sri Ramachandra Institute of Higher Education and Research (SRIHER), involving 30 patients who underwent cardiac valvular and coronary artery bypass grafting with valvular surgeries using CPB from March 2022 to July 2022. The patients were split into two groups: Group A (CPB with hemofiltration) and Group B (CPB without hemofiltration). Data measurements included hemoglobin, serum lactate, creatinine, blood urea nitrogen (BUN), and urine output. Statistical analysis was done utilizing a t-test along with chi-square test, with a probability value (PV) of P < 0.005 considered noteworthy.

Results and Discussion: Throughout cardiac bypass surgery (CPB), serum lactate levels are lower in Group A (mean- 1.87mmol/L) compared to Group B (mean-5.34mmol/L), and hemoglobin levels increase in Group A (mean-11.4 g/dL) compared to Group B (mean-8.3 g/dL). The incorporation of an ultrafilter during CPB significantly increases hemoglobin levels, reducing the need for blood transfusions. Postoperatively, serum lactate levels gradually increase in Group B (mean-4.9 mmol/L) and hemoglobin levels increase in Group A (mean-11.7 g/dL), reducing the need for blood transfusions and mechanical ventilation time. Additionally, serum creatinine levels decrease in Group A (hemofilter-induced CPB) compared to Group B (mean-3.21 mg/dL). BUN levels slightly increase in Group B.

Conclusion: Conventional ultrafiltration during CPB reduces hyperlactatemia risk, reducing mechanical ventilation time and ICU stay duration. It benefits short-term patients and those with preoperative renal dysfunction in the long run.