A BMI >35 does not protect patients undergoing cardiac bypass surgery from red blood cell transfusion.

The effect of obesity on allogeneic intraoperative blood product transfusion in patients undergoing coronary artery bypass graft surgery (CABG) is poorly understood. We analyzed the influence of obesity on the risk of intraoperative red blood cell (RBC) transfusion among 45,200 consecutive non-reoperative CABG procedures from a multi-institutional perfusion database. A body mass index (BMI) in obese I category was associated with a 9.9% decrease in transfusion risk (p<0.05). Compared to patients with a normal BMI, obese I and obese III patients do not have any change in the relative risk of RBC transfusion. Overweight and mild obesity have a protective role in reducing intraoperative blood transfusion during cardiopulmonary bypass (CPB) surgery. However, logistic regression analysis showed that much of the observed reduction in transfusion rates for obese patients can be accounted for by other known confounds. The lack of a linear effect of increasing BMI on blood transfusion risk is a novel finding and warrants further investigation.

The Influence of Intraoperative Autotransfusion on Postoperative Hematocrit after Cardiac Surgery: A Cross-Sectional Study.

Utilization of intraoperative autotransfusion (IAT) during cardiac surgery with cardiopulmonary bypass (CPB) has been shown to reduce allogeneic red blood cell transfusion. Previous research has emphasized the benefits of using IAT in the intraoperative period. The present study was designed to evaluate the effects of using IAT on overall hematocrit (Hct) drift between initiation of CPB and the immediate postoperative period. We reviewed 3,225 adult cardiac procedures occurring between February 2016 and January 2017 at 84 hospitals throughout the United States. Data were collected prospectively from adult patients undergoing cardiac surgery with CPB, and stored in the SpecialtyCare Operative Procedural rEgistry (SCOPE), a large quality improvement database. Patients receiving allogeneic transfusion and those with missing covariate data were excluded from analysis. The effect of IAT volume returned to patients on the primary endpoint, hematocrit change from CPB initiation to intensive care unit (ICU) entry, was assessed using a multivariable linear mixed effects regression model controlling for patient demographics, operative characteristics, surgeon, and hospital. Descriptive analysis showed greater positive hematocrit change with increasing autotransfusate volume returned. Those patients with no IAT volume returned saw a median hematocrit change of +2.00%, whereas those with more than 380 mL/m2 BSA had a median Hct drift of +5.00% (p < .001). After controlling for known confounds, our regression estimate of the effect of IAT volume returned on Hct drift was +.0045% per 1 mL/m2 BSA (p < .001). For a patient with the median autotransfusate volume returned (273 mL/m2 BSA), and all other covariate values at their respective medians, this translates to a predicted hematocrit change of +3.6% (95% CI +3.1 to +4.1). These findings lend further support to the notion that autotransfusate volume is positively associated with increases in postoperative hematocrit.

Utility of cell salvage in women undergoing abdominal myomectomy.

OBJECTIVE: We examined the use and cost of autologous blood cell salvage in women who undergo abdominal myomectomy. STUDY DESIGN: Patients who underwent abdominal myomectomy from 2007-2011 were identified. Use of the cell salvage system and reinfusion of autologous blood in women who had the system set-up were analyzed. Cost was examined by directly reported data. RESULTS: We identified 607 patients who underwent abdominal myomectomy. Four hundred twenty-five women (70%) had the set-up of the cell salvage system. Cell-salvaged blood was processed and reinfused into 85 of these subjects (20%). In a multivariable model, performance of myomectomy by a gynecologic-specific surgeon (odds ratio [OR], 2.14; 95% confidence interval [CI], 1.28-3.59), >5 myomas (OR, 2.49; 95% CI, 1.27-4.89), and larger uterine size statistically were associated significantly with cell-salvage device set-up. Conversely, having a reproductive-endocrinology-infertility specialist as the surgeon was associated with a significant reduction in cell-salvage system set-up (OR, 0.37; 95% CI, 0.21-0.66). For the women who had cell-salvage system set-up, uterine size of >15-19 weeks of gestation (OR, 3.22; 95% CI, 1.56-8.95) or ≥20 weeks of gestation (OR, 4.62; 95% CI, 1.45-14.73), operating time of >120 minutes (OR, 3.98; 95% CI, 1.70-9.29), and intraoperative blood loss of >1000 mL (OR, 26.31; 95% CI, 10.49-65.99) were associated significantly with a higher incidence of reinfusion of cell-salvaged blood. CONCLUSION: The routine use of cell salvage in women who undergo abdominal myomectomy does not appear to be warranted. Cell-salvage set-up appears to be cost-effective only when reinfused, but clinical characteristics cannot predict accurately which women will require reinfusion of cell-salvaged blood.