Acute normovolemic hemodilution reduces allogeneic red blood cell transfusion in cardiac surgery: a systematic review and meta-analysis of randomized trials
Anesthesia and Analgesia. 2016;124((3):):743-752
BACKGROUND To better understand the role of acute normovolemic hemodilution (ANH) in a surgical setting with high risk of bleeding, we analyzed all randomized controlled trials (RCTs) in the setting of cardiac surgery that compared ANH with standard intraoperative care. The aim was to assess the incidence of ANH-related number of allogeneic red blood cell units (RBCu) transfused. Secondary outcomes included the rate of allogeneic blood transfusion and estimated total blood loss. METHODS Twenty-nine RCTs for a total of 2439 patients (1252 patients in the ANH group and 1187 in the control group) were included in our meta-analysis using PubMed/MEDLINE, Cochrane Controlled Trials Register, and EMBASE. RESULTS Patients in the ANH group received fewer allogeneic RBCu transfusions (mean difference = -0.79; 95% confidence interval [CI], -1.25 to -0.34; P = .001; I = 95.1%). Patients in the ANH group were overall transfused less with allogeneic blood when compared with controls (356/845 [42.1%] in the ANH group versus 491/876 [56.1%] in controls; risk ratio = 0.74; 95% CI, 0.62 to 0.87; P < .0001; I = 72.5%), and they experienced less postoperative blood loss (388 mL in ANH versus 450 mL in control; mean difference = -0.64; 95% CI, -0.97 to -0.31; P < .0001; I = 91.8%). CONCLUSIONS ANH reduces the number of allogeneic RBCu transfused in the cardiac surgery setting together with a reduction in the rate of patients transfused with allogeneic blood and with a reduction of bleeding.
The efficacy of an intraoperative cell saver during cardiac surgery: a meta-analysis of randomized trials
Anesthesia and Analgesia. 2009;109((2):):320-30.
BACKGROUND Cell salvage may be used during cardiac surgery to avoid allogeneic blood transfusion. It has also been claimed to improve patient outcomes by removing debris from shed blood, which may increase the risk of stroke or neurocognitive dysfunction. In this study, we sought to determine the overall safety and efficacy of cell salvage in cardiac surgery by performing a systematic review and meta-analysis of published randomized controlled trials. METHODS A comprehensive search was undertaken to identify all randomized trials of cell saver use during cardiac surgery. MEDLINE, Cochrane Library, EMBASE, and abstract databases were searched up to November 2008. All randomized trials comparing cell saver use and no cell saver use in cardiac surgery and reporting at least one predefined clinical outcome were included. The random effects model was used to calculate the odds ratios (OR, 95% confidence intervals [CI]) and the weighted mean differences (WMD, 95% CI) for dichotomous and continuous variables, respectively. RESULTS Thirty-one randomized trials involving 2282 patients were included in the meta-analysis. During cardiac surgery, the use of an intraoperative cell saver reduced the rate of exposure to any allogeneic blood product (OR 0.63, 95% CI: 0.43-0.94, P = 0.02) and red blood cells (OR 0.60, 95% CI: 0.39-0.92, P = 0.02) and decreased the mean volume of total allogeneic blood products transfused per patient (WMD -256 mL, 95% CI: -416 to -95 mL, P = 0.002). There was no difference in hospital mortality (OR 0.65, 95% CI: 0.25-1.68, P = 0.37), postoperative stroke or transient ischemia attack (OR 0.59, 95% CI: 0.20-1.76, P = 0.34), atrial fibrillation (OR 0.92, 95% CI: 0.69-1.23, P = 0.56), renal dysfunction (OR 0.86, 95% CI: 0.41-1.80, P = 0.70), infection (OR 1.25, 95% CI: 0.75-2.10, P = 0.39), patients requiring fresh frozen plasma (OR 1.16, 95% CI: 0.82-1.66, P = 0.40), and patients requiring platelet transfusions (OR 0.90, 95% CI: 0.63-1.28, P = 0.55) between cell saver and noncell saver groups. CONCLUSIONS Current evidence suggests that the use of a cell saver reduces exposure to allogeneic blood products or red blood cell transfusion for patients undergoing cardiac surgery. Subanalyses suggest that a cell saver may be beneficial only when it is used for shed blood and/or residual blood or during the entire operative period. Processing cardiotomy suction blood with a cell saver only during cardiopulmonary bypass has no significant effect on blood conservation and increases fresh frozen plasma transfusion.