Red blood cell transfusion in surgery: an observational study of the trends in the USA from 2011 to 2016

Perioperative Transfusion and Mortality for Cardiovascular Surgery: A Cohort Study Based on Population in Republic of Korea

Objective:This study aimed to evaluate the rate of transfusion for cardiovascular surgeries between 2010 and 2019 in Republic of Korea and the association between blood transfusion and postoperative mortality. Methods: Data were extracted from the National Health Insurance Service database in Republic of Korea. This study includes adult patients who underwent cardiovascular surgery between 1 January 2010 and 31 December 2019. The endpoints were in-hospital mortality and the 1-year all-cause mortality. Results: The analysis included 62,794 cases, with transfusions used in 88.8% of cases. Multivariable logistic regression revealed that older age, comorbidities, hospital admission through the emergency room, aortic procedures (versus coronary artery bypass grafting), cardiopulmonary bypass, repeat procedures, and supportive therapies during the intensive care (extracorporeal membrane oxygenation and mechanical ventilation) were risk factors for blood transfusion. Female sex was associated with a lower risk of transfusion. Perioperative blood transfusion was associated with a 6.87-fold increased risk of in-hospital mortality (odds ratio [OR]: 6.87, 95% confidence interval [CI]: 3.95, 11.93; p < 0.001) and a 3.20-fold increased risk of 1-year all-cause mortality (OR: 3.35, 95% CI: 2.75, 3.93; p < 0.001). Conclusions: Blood transfusion is used at a high rate in cardiovascular surgeries, and it was associated with increases in the risk of in-hospital and 1-year all-cause mortality. However, these correlations should be viewed with caution as emergent phenomena rather than causative. Understanding factors associated with the need for blood transfusion can assist surgeons in predicting the outcomes of cardiovascular surgery and in tailoring procedures as needed to optimize outcomes.

Differential impact of transfusion guidelines on blood transfusion practices within a health network

Whether clinical practice guidelines have a significant impact on practice is unclear. The effect of guideline recommendations on clinical practice often a lags behind the date of publication. We evaluated by means of a data-driven approach if and when the guidelines on red blood cell transfusions (RBCTs) issued by Swiss Smarter Medicine in 2016 had an impact on RBCTs practice within a hospital network, where awareness of guidelines was promoted mainly among internal medicine specialties. Data on RBCTs performed in a Swiss hospital network from January 2014 to April 2021 were analyzed by hospital site and specialty to assess whether guidelines led to a decrease in inappropriate RBCTs. RBCTs were defined as "inappropriate" if patients had a hemoglobin level ≥ 70 g/L without or ≥ 80 g/L with significant cardiovascular comorbidities. Changes in the rate of inappropriate transfusions were analyzed with an advanced statistical approach that included generalized additive models. Overall prior to March 2017 there were more inappropriate than appropriate RBCTs, but after October 2017 the opposite could be observed. A change-point in the time trend was estimated from transfusion data to occur in the time interval between March and October 2017. This change was mainly driven by practice changes in the medical wards, while no significant change was observed in the critical care, surgical and oncology wards. Change in practice varied by hospital site. In conclusion, our results show that a significant change in the RBCTs practice at the hospital level occurred approximately 18 months after national guidelines were issued.

Blood Transfusions and Adverse Events after Colorectal Surgery: A Propensity-Score-Matched Analysis of a Hen-Egg Issue

Blood transfusions are considered a risk factor for adverse outcomes after colorectal surgery. However, it is still unclear if they are the cause (the hen) or the consequence (the egg) of adverse events. A prospective database of 4529 colorectal resections gathered over a 12-month period in 76 Italian surgical units (the iCral3 study), reporting patient-, disease-, and procedure-related variables, together with 60-day adverse events, was retrospectively analyzed identifying a subgroup of 304 cases (6.7%) that received intra- and/or postoperative blood transfusions (IPBTs). The endpoints considered were overall and major morbidity (OM and MM, respectively), anastomotic leakage (AL), and mortality (M) rates. After the exclusion of 336 patients who underwent neo-adjuvant treatments, 4193 (92.6%) cases were analyzed through a 1:1 propensity score matching model including 22 covariates. Two well-balanced groups of 275 patients each were obtained: group A, presence of IPBT, and group B, absence of IPBT. Group A vs. group B showed a significantly higher risk of overall morbidity (154 (56%) vs. 84 (31%) events; OR 3.07; 95%CI 2.13-4.43; p = 0.001), major morbidity (59 (21%) vs. 13 (4.7%) events; OR 6.06; 95%CI 3.17-11.6; p = 0.001), and anastomotic leakage (31 (11.3%) vs. 8 (2.9%) events; OR 4.72; 95%CI 2.09-10.66; p = 0.0002). No significant difference was recorded between the two groups concerning the risk of mortality. The original subpopulation of 304 patients that received IPBT was further analyzed considering three variables: appropriateness of BT according to liberal transfusion thresholds, BT following any hemorrhagic and/or major adverse event, and major adverse event following BT without any previous hemorrhagic adverse event. Inappropriate BT was administered in more than a quarter of cases, without any significant influence on any endpoint. The majority of BT was administered after a hemorrhagic or a major adverse event, with significantly higher rates of MM and AL. Finally, a major adverse event followed BT in a minority (4.3%) of cases, with significantly higher MM, AL, and M rates. In conclusion, although the majority of IPBT was administered with the consequence of hemorrhage and/or major adverse events (the egg), after adjustment accounting for 22 covariates, IPBT still resulted in a definite source of a higher risk of major morbidity and anastomotic leakage rates after colorectal surgery (the hen), calling urgent attention to the implementation of patient blood management programs.

Red Blood Cell Transfusion and Postoperative Infection in Patients Having Coronary Artery Bypass Grafting Surgery: An Analysis of the Society of Thoracic Surgeons Adult Cardiac Surgery Database

BACKGROUND

Coronary artery bypass grafting (CABG) is the most common cardiac surgical procedure in the world and up to one-third of patients are transfused red blood cells (RBCs). RBC transfusion may increase the risk for health care-associated infection (HAI) after CABG, but previous studies have shown conflicting results and many did not establish exposure temporality. Our objective was to explore whether intraoperative RBC transfusion is associated with increased odds of postoperative HAI. We hypothesized that intraoperative RBC transfusion would be associated with increased odds of postoperative HAI.

METHODS

We performed an observational cohort study of isolated CABG patients in the Society of Thoracic Surgeons adult cardiac surgery database from July 1, 2017, to June 30, 2019. The exposure was intraoperative RBC transfusion modeled as 0, 1, 2, 3, or 4+ units. The authors focused on intraoperative RBC transfusion as a risk factor, because it has a definite temporal relationship before postoperative HAI. The study's primary outcome was a composite HAI variable that included sepsis, pneumonia, and surgical site infection (both deep and superficial). Mixed-effects modeling, which controlled for hospital as a clustering variable, was used to explore the relationship between intraoperative RBC transfusion and postoperative HAI.

RESULTS

Among 362,954 CABG patients from 1076 hospitals included in our analysis, 59,578 patients (16.4%) received intraoperative RBCs and 116,186 (32.0%) received either intraoperative or postoperative RBCs. Risk-adjusted odds ratios for HAI in patients who received 1, 2, 3, and 4+ intraoperative RBCs were 1.11 (95% confidence interval [CI], 1.03-1.20; P = .005), 1.13 (95% CI, 1.05-1.21; P = .001), 1.15 (95% CI, 1.04-1.27; P = .008), and 1.14 (95% CI, 1.02-1.27; P = .02) compared to patients who received no RBCs.

CONCLUSIONS

Intraoperative RBC transfusion is associated with a small increase in odds of HAI in CABG patients. Future studies should explore whether reductions in RBC transfusion can also reduce HAIs.