Effect of retrograde autologous priming on lactate and hemoglobin levels of adult patients undergoing coronary artery bypass grafting

Background:   Reduced hemoglobin, excessive transfusions and raised lactate levels are important determinants of patient outcome after cardiopulmonary bypass. Many strategies have been studied for optimum management of these parameters. In this study, we evaluated the impact of retrograde autologous priming (RAP) method on hemoglobin and lactate levels in patients undergoing coronary artery bypass grafting (CABG) on cardiopulmonary bypass. Methodology: This prospective randomized controlled trial was conducted at Army Cardiac Centre, CMH, Lahore, from January 01, 2021 to June 30, 2021. After approval of institutional ethical committee and taking informed consent from patients, 272 patients undergoing CABG were enrolled. Patients with ages less than 18 y, LVEF ≤ 20%, emergency operations, repeat operations, valvular or combined procedures, recent myocardial infarction, with preoperative lactate levels of more than 2 mmol/L and Hb of less than 9 gm/dL and other preoperative systemic diseases or infection were excluded.  Patients were divided into two groups. Group A received conventional priming of bypass circuit with ringer lactate, and Group B received RAP with patient’s own blood. Hb and lactate levels were measured in arterial blood gases before induction and upon weaning from bypass. Results: The demographic features of both groups were identical, Group A patients had significantly high levels of lactate (3.76 ± 0.81 vs. 2.64 ± 0.47 mmol/L, P < 0.01). Hb levels of patients in RAP (RAP) (Group B) were significantly better (9 ± 0.31 vs. 7.9 ± 0.39 gm/dL, P < 0.01) than Group A. Conclusion: Our study concludes that when compared with crystalloid priming, retrograde autologous priming technique is associated with reduced lactate levels and better hemoglobin levels after cardiopulmonary bypass in patients undergoing coronary artery bypass grafting. Abbreviations: CABG - Coronary artery bypass grafting; CPB - cardiopulmonary bypass; LVEF – Left ventricular ejection fraction; Hb – Hemoglobin; RAP – Retrograde autologous priming; FFP - Fresh frozen plasma; Key words: cardiopulmonary bypass; coronary artery bypass grafting; lactate levels, retrograde autologous priming. Citation: Naseer M, Feroze R, Akram MA, Fakhar-e-Fayaz. Effect of retrograde autologous priming on lactate and hemoglobin levels of adult patients undergoing coronary artery bypass grafting. Anaesth. pain intensive care 2022;26(1):20–24   DOI: 10.35975/apic.v26i1.1761 Received: October 4, 2021, Reviewed: November 14, 2021,, Accepted: January 19, 2022