Ultrafiltration in cardiac surgery: Results of a systematic review and meta-analysis

Abstract

Background: Ultrafiltration is used with cardiopulmonary bypass to reduce the effects of hemodilution and restore electrolyte balance. We performed a systematic review and meta-analysis to analyze the effect of conventional and modified ultrafiltration on intraoperative blood transfusion. Methods: Utilizing the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement, we systematically searched MEDLINE, EMBASE, Web of Science, and Cochrane Library to perform a meta-analysis of studies of randomized controlled trials (RCTs) and observational studies evaluating conventional ultrafiltration (CUF) and modified ultrafiltration (MUF) on the primary outcome of intraoperative red cell transfusions. Results: A total of 7 RCTs ( n = 928) were included, comparing modified ultrafiltration ( n = 473 patients) to controls ( n = 455 patients) and 2 observational studies ( n = 47,007), comparing conventional ultrafiltration ( n = 21,748) to controls ( n = 25,427). Overall, MUF was associated with transfusion of fewer intraoperative red cell units per patient ( n = 7); MD −0.73 units; 95% CI −1.12 to −0.35 p = 0.04; p for heterogeneity = 0.0001, I 2 = 55%) compared to controls. CUF was no difference in intraoperative red cell transfusions compared to controls ( n = 2); OR 3.09; 95% CI 0.26–36.59; p = 0.37; p for heterogeneity = 0.94, I 2 = 0%. Review of the included observational studies revealed an association between larger volumes (>2.2 L in a 70 kg patient) of CUF and risk of acute kidney injury (AKI). Conclusion: The results of this systematic review and meta-analysis suggest that MUF is associated with fewer intraoperative red cell transfusions. Based on limited studies, CUF does not appear to be associated with a difference in intraoperative red cell transfusion.

Perioperative Plasma in Addition to Red Blood Cell Transfusions Are Associated With Increased Venous Thromboembolism Risk Postoperatively

“…Due to the nature of surgery, 10% 15% of the US blood supply is allocated for cardiac surgical patients with approximately 40% to 60% of patients receiving an allogeneic transfusion during hospitalization. 22,23 Blood conservation practices in cardiac and other surgeries include (1) preoperative anemia management, (2) retrograde autologous priming, 24 (3) acute normovolemic hemodilution, (4) antifibrinolytics, (5) restrictive hemoglobin transfusion triggers, (6) viscoelastic testing transfusion algorithms, (7) modified ultrafiltration on bypass, 25 (8) cell salvage, and (9) hemostatic sealants. These strategies aim to prevent unnecessary transfusions and prevent coagulopathy.…”

Modified Ultrafiltration and Acute Kidney Injury in Patients Undergoing Open Heart Surgery Using Cardiopulmonary Bypass

“…16 According to some research, using UF during CPB to remove extra fluid is not kidney protective and may even harm the kidneys if the fluid withdrawn is greater than what is required. 17 Recent evaluations have also cautioned us to avoid AKI by limiting UF in individuals with impaired renal function. 18 Luciani et al conducted a trial on the use of MUF on clinical outcomes after CPB, the authors reported mean postoperative hemoglobin level 11.1±1.6 g/dl in MUF versus 11.2±1.8 g/dl without MUF (p>0.05).…”