Acute normovolemic hemodilution in cardiac surgery and the power of global collaboration in advancing research

Acute normovolemic hemodilution (ANH) is a blood conservation strategy in cardiac surgery aimed at reducing perioperative need for transfusion and preserving hemostatic function. While ANH has potential benefits, its global adoption remains heterogeneous and poorly characterized. To investigate current practice patterns, we conducted a rapid international survey among cardiac anesthesiologists, disseminated through the International Academy of Cardiac Anaesthesiologists (IACA) global network and the European Association of Cardiothoracic Anaesthesiology (EACTAIC). We reached specialists from 31 countries, with 28 providing responses: on average, 26.7% of cardiac anesthesiologists reported using ANH and 13.7% of cardiac surgery patients worldwide actually receive ANH, rising to 17.5% when considering a population-weighted mean. Notable regional variability was observed, ranging from 37.3% use in the Americas to just 5.0% in Oceania. These findings reinforce previous reports and underscore the ongoing global disparities in ANH implementation. Moreover, this study highlights the power of international collaboration in addressing knowledge gaps and establishing global benchmarks. By engaging national leaders and taking advantage of inter-societal cooperation, the survey not only provided meaningful insights but also demonstrated the feasibility of rapidly gathering global data on specific perioperative practices. Ultimately, this study lays the groundwork for multicenter research and calls for a large randomized international trial to definitively assess the clinical impact of ANH in cardiac surgery.

Acute normovolemic hemodilution; Anesthesiology; Cardiac surgery; International survey; Transfusion

[1] Engoren MC, Habib RH, Zacharias A, Schwann TA, Riordan CJ, Durham SJ. Effect of blood transfusion on long-term survival after cardiac operation. The Annals of Thoracic Surgery. 2002; 74: 1180–1186.

[2] Goodnough LT, Shieh L, Hadhazy E, Cheng N, Khari P, Maggio P. Improved blood utilization using real-time clinical decision support. Transfusion. 2014; 54: 1358–1365.

[3] Paone G, Likosky DS, Brewer R, Theurer PF, Bell GF, Cogan CM, et al. Transfusion of 1 and 2 units of red blood cells is associated with increased morbidity and mortality. The Annals of Thoracic Surgery. 2014; 97: 87–93; discussion 93–94.

[4] Stammers AH, Mongero LB, Tesdahl E, Stasko A, Weinstein S. The effectiveness of acute normolvolemic hemodilution and autologous prime on intraoperative blood management during cardiac surgery. Perfusion. 2017; 32: 454–465.

[5] Goldberg J, Paugh TA, Dickinson TA, Fuller J, Paone G, Theurer PF, et al. Greater volume of acute normovolemic hemodilution may aid in reducing blood transfusions after cardiac surgery. The Annals of Thoracic Surgery. 2015; 100: 1581–1587; discussion 1587.

[6] Monaco F, Guarracino F, Vendramin I, Lei C, Zhang H, Lomivorotov V, et al. Acute normovolemic hemodilution in cardiac surgery: rationale and design of a multicenter randomized trial. Contemporary Clinical Trials. 2024; 143: 107605.

[7] Tanaka K, Vandyck K, Burkhart H, et al. Acute normovolemic hemodilution in a multi-center adult cardiac surgery setting: a propensity score-matched analysis using the society of thoracic surgeons adult cardiac surgery database. Society of cardiovascular anesthesiologists annual meeting & workshop. Monreal, Canada 2025. Available from: https://scahq.org/wp-content/uploads/2025/04/SCA-2025-AM-Program_FINAL-1.pdf (Accessed: 02 May 2025).

[8] Zhou ZF, Jia XP, Sun K, Zhang FJ, Yu LN, Xing T, et al. Mild volume acute normovolemic hemodilution is associated with lower intraoperative transfusion and postoperative pulmonary infection in patients undergoing cardiac surgery—a retrospective, propensity matching study. BMC Anesthesiology. 2017; 17: 13.

[9] Barile L, Fominskiy E, Di Tomasso N, Alpìzar Castro LE, Landoni G, De Luca M, et al. Acute normovolemic hemodilution reduces allogeneic red blood cell transfusion in cardiac surgery: a systematic review and meta-analysis of randomized trials. Anesthesia & Analgesia. 2017; 124: 743–752.