Greater Volume of Acute Normovolemic Hemodilution May Aid in Reducing Blood Transfusions After Cardiac Surgery

Abstract

Background Perioperative red blood cell transfusions (RBC) are associated with increased morbidity and mortality after cardiac surgery. Acute normovolemic hemodilution (ANH) is recommended to reduce perioperative transfusions; however, supporting data are limited and conflicting. We describe the relationship between ANH and RBC transfusions after cardiac surgery using a multi-center registry. Methods We analyzed 13,534 patients undergoing cardiac surgery between 2010 and 2014 at any of the 26 hospitals participating in a prospective cardiovascular perfusion database. The volume of ANH (no ANH, <400mL, 400–799mL, ≥800mL) was recorded and linked to each center’s surgical data. We report adjusted relative risks reflecting the association between the use and amount of ANH and the risk of perioperative RBC transfusion. Results were adjusted for preoperative risk factors, procedure, BSA, preoperative HCT, and center. Results ANH was used in 17% of the patients. ANH was associated with a reduction in RBC transfusions (RRadj 0.74, p <0.001). Patients having ≥800mL of ANH had the most profound reduction in RBC transfusions (RRadj 0.57, p<0.001). Platelet and plasma transfusions were also significantly lower with ANH. The ANH population had superior postoperative morbidity and mortality compared to the no ANH population. Conclusions There is a significant association between ANH and reduced perioperative RBC transfusion in cardiac surgery. Transfusion reduction is most profound with larger volumes of ANH. Our findings suggest the volume of ANH, rather than just its use, may be an important feature of a center’s blood conservation strategy.

A review of the application of autologous blood transfusion

“…It has been widely used in postpartum hemorrhage, and cancer and orthopedic surgeries, such as joint replacement and spine surgery. These surgeries often have large traumatic areas and a large amount of bleeding, and patients often need blood transfusions (24 -26). ANH advantages include the following.…”

The effect of acute normovolemic hemodilution on plasma fibrinogen level in coronary artery bypass grafting

“…Recent guidelines have suggested that fibrinogen levels should be >200 mg/dL for sufficient clot strength. [9] In the present study, we found that ANH significantly attenuated the decline in fibrinogen, and significantly more patients in ANH group had a fibrinogen level of >200 mg/dL; however, the mean volume of chest tube drainage during the first 24 hours were similar between the groups. This may indicate that both groups had similar amount of bleeding.…”

“…[8] However, a recent clinical trial reported a reduced need for transfusion in parallel with the amount of the collected whole blood. [9] Low levels of fibrinogen may increase the need for red blood cell (RBC) transfusion. [10] In this study, we hypothesized that ANH may preserve postoperative plasma levels of fibrinogen and reduce the need for allogeneic blood cell transfusion.…”

Blood conservation in cardiac surgery

“…In 2015, Goldberg et al . published a multicentre prospective observational study including 13 534 patients undergoing cardiac surgery (Goldberg et al, ). ANH patients were divided into three groups: those who had less than 400 mL removed, those who had 400 to 799 mL removed and those who had 800 mL or greater removed.…”