Clinical Effectiveness of Acute Normovolemic Hemodilution in Cardiac Surgery: A Systematic Review and Meta-analysis
- Journal
- Anesthesia and analgesia (Q1)
- Published
- 13 July 2026
- Study design
- Systematic review / meta-analysis of RCTs
- Evidence level
- Level 1, High (CEBM 1a)
- Authors
- Mahmoud Elfiki, Abdalla Elfeky, Mustafa Shafeeq Ali, Amr Ibrahim, Mariem Zayed, Amira Fahmy El-Nemr, et al.
- PMID
- 42442348
- DOI
- 10.1213/ANE.0000000000008221
Why clinicians should know about it
- Picked for Anesthesiology and Pain Medicine (top studies of the week, 19 July 2026).
- Picked for Nephrology (top studies of the week, 19 July 2026).
Abstract
BACKGROUND: Acute normovolemic hemodilution (ANH) is endorsed by contemporary patient blood management guidelines as a cost-effective strategy for reducing allogeneic transfusion in cardiac surgery. However, evidence remains inconsistent due to protocol variability and limited statistical power in earlier trials. This systematic review and meta-analysis seek to evaluate the clinical effectiveness of ANH in adult patients undergoing cardiac surgery. METHODS: A comprehensive search of four databases was performed up to October 2025 to identify randomized controlled trials (RCTs) and matched cohort studies comparing ANH with standard intraoperative care. The primary outcome of interest was the incidence of allogeneic red blood cell (RBC) transfusion. Data were pooled using DerSimonian-Laird random-effects models, expressed as risk ratios (RR) or mean differences (MD) with 95% confidence intervals (CI). RESULTS: Nineteen studies (15 RCTs, four cohorts) involving 9418 patients were included. ANH significantly reduced the incidence of allogeneic RBC transfusion compared with control (27.6% vs 31.5%; RR = 0.85, 95% CI [0.75-0.96], P = .01). The transfusion reduction was more evident in crystalloid-based protocols (RR = 0.72, 95% CI [0.54-0.96], P = .026) and on-pump surgeries (RR = 0.86, 95% CI [0.76-0.97], P = .01). Matched cohort analyses also confirmed the benefit (RR = 0.87, 95% CI [0.81-0.94], P = .001), whereas RCT-only analysis showed a nonsignificant difference (RR = 0.81, 95% CI [0.64-1.02], P = .07). No significant differences were found in hematocrit, hemoglobin, fresh frozen plasma transfusion, renal dysfunction, myocardial infarction, stroke, or mortality. CONCLUSION: ANH significantly reduces the need for allogeneic transfusions while maintaining a favorable safety profile for patients undergoing cardiac surgery.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.