The incidence and importance of anaemia in patients undergoing cardiac surgery in the UK - the first Association of Cardiothoracic Anaesthetists national audit

Prognostic Impact of Anemia and Blood Transfusions on Cardiovascular Outcomes in Patients Undergoing Vascular Surgery: A Scoping Review

OBJECTIVE

Prior studies suggest an association of anemia and blood transfusion with increased morbidity and mortality in patients undergoing cardiac surgery. However, the impact of perioperative anemia and blood transfusion on clinical outcomes in patients undergoing major vascular surgery has been poorly defined yet. The primary objectives of this scoping review were to determine the extent of the evidence base that links anemia and blood transfusions to mortality and cardiovascular outcomes in patients undergoing major vascular surgery, and identify recurring themes or gaps in the literature to guide future research.

METHODS

A scoping review of the literature from PubMed, Cochrane, and EMBASE databases was conducted up to December 2023 to identify articles related to the impact of anemia and blood transfusions on postoperative cardiovascular outcomes on patients undergoing vascular surgery. Methodology followed the PRISMA Protocols Extension for Scoping Reviews.

RESULTS

Twenty-two articles met the inclusion criteria, including 15 retrospective and 6 observational prospective studies. Anemia definition varied across studies, mainly based on hemoglobin cut-off levels. An association with older age, coronary artery disease, hypertension, diabetes, and other comorbidities was reported. Particularly in peripheral and endovascular aortic surgery, anemia was linked consistently with higher mortality, major adverse cardiac events, and other postoperative complications, such as respiratory and renal issues, surgical site infections, and longer hospital stays, depending on hemoglobin levels. Anemia itself is an important predictor of transfusions. Transfusions in anemic patients were associated with increased mortality, postoperative complications, and increased need for major amputation.

CONCLUSIONS

The weight of the evidence suggests that anemia carries a substantial burden of cardiovascular complications, mortality, and multiorgan complications, resulting in increased health care costs. Peripheral and endovascular aortic surgery are affected deeply by the impact of anemia. Anemia itself stands out as a crucial predictor for requiring transfusions. In turn, the effect of transfusion of blood products is associated with worse outcomes and complications.

Association of Anaesthetists guidelines: the use of blood components and their alternatives 2024

BACKGROUND

The administration of blood components and their alternatives can be lifesaving. Anaemia, bleeding and transfusion are all associated with poor peri-operative outcomes. Considerable changes in the approaches to optimal use of blood components and their alternatives, driven by the findings of large randomised controlled trials and improved haemovigilance, have become apparent over the past decade. The aim of these updated guidelines is to provide an evidence-based set of recommendations so that anaesthetists and peri-operative physicians might provide high-quality care.

METHODS

An expert multidisciplinary, multi-society working party conducted targeted literature reviews, followed by a three-round Delphi process to produce these guidelines.

RESULTS

We agreed on 12 key recommendations. Overall, these highlight the importance of organisational factors for safe transfusion and timely provision of blood components; the need for protocols that are targeted to different clinical contexts of major bleeding; and strategies to avoid the need for transfusion, minimise bleeding and manage anticoagulant therapy.

CONCLUSIONS

All anaesthetists involved in the care of patients at risk of major bleeding and peri-operative transfusion should be aware of the treatment options and approaches that are available to them. These contemporary guidelines aim to provide recommendations across a range of clinical situations.

Effect of perioperative erythropoietin on postoperative morbidity and mortality after cardiac surgery: a meta-analysis of randomized controlled trials

OBJECTIVE

Cardiac surgery is known to have high rates of perioperative red blood cell (RBC) transfusions which are associated with increased postoperative mortality and morbidity. Perioperative erythropoietin (EPO) has been suggested to lower perioperative RBC transfusions, and the effect on postoperative morbidity or mortality is unknown.

METHODS

The registered study protocol is available on PROSPERO (CRD42022314538). We searched the Pubmed, EMbase, and Cochrane CENTRAL databases for randomized controlled trials (RCT) of EPO in cardiac surgery. Outcomes were short-term mortality, acute kidney injury (AKI), re-operation, cerebrovascular accident (CVA), perioperative myocardial infarction (MI), infectious complications, and RBC transfusions. RCT studies of perioperative EPO that reported at least one prespecified outcome of interest were included.

RESULTS

A total of 21 RCT's (n = 2,763 patients) were included. Mortality analysis included 17 studies (EPO 1,272 patients, control 1,235) and showed no significant difference (risk difference (RD) 0.0004, 95%CI: -0.016, 0.009). EPO did not reduce the incidence of AKI (RD -0.006, 95% CI: -0.038, 0.026) and reoperation (RD 0.001, 95% CI: -0.013, 0.015). The incidence of CVA (RD -0.004, 95% CI: -0.015, 0.007) and perioperative MI (RD -0.008, 95% CI: -0.021, 0.005) was similar between the groups.

CONCLUSIONS

Although EPO had been proven to reduce perioperative RBC transfusions, we did not find that it reduces the incidence of postoperative short-term mortality, AKI, and reoperation. The study results support that perioperative EPO is also safe, with no rise in thrombotic events, including CVA and perioperative MI.

Preoperative Anemia and Iron Deficiency in Elective Gastrointestinal Cancer Surgery Patients

BACKGROUND AND OBJECTIVES

Preoperative anemia can impact postoperative outcomes, but its importance in gastrointestinal cancer patients, and significance of anemia etiology remains unclear. We aimed to characterize the frequency and impact of preoperative anemia, and iron-deficiency anemia (IDA), on perioperative outcomes.

METHODS

We performed a retrospective cohort study of adult patients undergoing elective gastrointestinal cancer surgery. The primary outcome was the incidence of perioperative RBC transfusion. Secondary outcomes included 90-day postoperative major morbidity, ICU admission, and 90-day hospital readmission. Multivariable analyses were performed to assess the association between preoperative anemia and IDA and outcomes.

RESULTS

Preoperative anemia was present in 55.5% of patients (n = 15 414), and 58.3% of anemic patients were iron deficient. Preoperative anemia was independently associated with increased risk of RBC transfusion (RR 2.88, 95% CI 2.60-3.20), and secondary outcomes. For every preoperative hemoglobin decrease of 1 g/dL, the adjusted risk of perioperative RBC transfusion increased by 40% (RR 1.39, 95% CI 1.37-1.42).

CONCLUSION

Preoperative anemia is prevalent, and an independent risk factor for adverse postoperative outcomes. Decreases in preoperative hemoglobin levels elevate the risk of transfusion and adverse outcomes, supporting further study to optimize management of treatable causes of preoperative anemia including IDA.

Association between perioperative hemoglobin decrease and outcomes of transfusion in patients undergoing on-pump cardiac surgery: An observational study from two Chinese heart centers

Background

It is unclear how perioperative hemoglobin decrease (ΔHb) influences the balance between risks and benefits of red blood cell transfusion after cardiac surgery.

Methods

We retrospectively analyzed data on 8186 adults who underwent valve surgery and/or coronary artery bypass grafting under cardiopulmonary bypass at two large cardiology centers. We explored the potential association of ΔHb, defined relative to the preoperative level and postoperative nadir, with a composite outcome of in-hospital mortality, myocardial infarction, stroke, and acute kidney injury using multivariable logistic regression, restricted cubic spline, and piecewise-linear models.

Results

Among 6316 patients without preoperative anemia, ΔHb ≥ 50 % was associated with an elevated risk of the composite outcome [adjusted odds ratio (aOR) 1.95, 95 % confidence interval (CI) 1.81-2.35]. Among 869 patients without preoperative anemia and with ΔHb ≥ 50 %, postoperative transfusion of no more than four units of red blood cell appeared to decrease the risk of the composite outcome, whereas transfusion of more than six units increased risk. Among 5447 patients without preoperative anemia and with ΔHb < 50 %, postoperative transfusion appeared not to decrease the risk of the composite outcome. Among 1870 patients with preoperative anemia, ΔHb ≥ 30 % significantly increased the risk of the composite outcome (aOR 1.61, 95 % CI 1.23-2.10), and this risk might be moderated by postoperative transfusion of no more than four units of red blood cell, but increased by transfusion of more than six units.

Conclusions

ΔHb may influence the balance between risks and benefits of red blood cell transfusion after cardiac surgery.

The burden of pre-operative anaemia and postoperative outcomes in 15 166 surgical patients from a public hospital in Brazil: A retrospective cohort study

BACKGROUND

Preoperative anaemia is associated with poor postoperative outcomes; however, few studies have reported its prevalence in developing countries and its association with significant postoperative outcomes.

OBJECTIVE

We aimed to identify the prevalence of anaemia and its association with postoperative outcomes in a major public hospital in Brazil.

DESIGN

Retrospective cohort study.

SETTING

Single-centre, 860-bed, quaternary university-affiliated teaching hospital in Southern Brazil.

PATIENTS

We included adult patients who had undergone surgery between 2015 and 2019. Main outcome measures: The main outcome was the in-hospital 30-day postoperative mortality. According to the World Health Organisation, we defined anaemia and its sub-classification (mild, moderate, and severe). We developed Poisson regression models to examine the association between preoperative anaemia and outcomes.

RESULTS

We included 15 166 patients, of whom 6387 (42.1%) were anaemic. After adjustment for confounding factors, patients with anaemia had an increased risk of in-hospital 30-day postoperative mortality (relative risk (RR) 1.69, 95% confidence interval (CI) 1.44 to 1.99, P < 0.001). Mild [relative risk (RR) 1.38, 95% CI 1.12 to 1.71, P = 0.003], moderate (RR 1.73, 95% CI 1.43 to 2.10, P < 0.001), and severe anaemia (RR 2.43, 95% CI 1.92 to 3.07, P < 0.001) were associated with the primary outcome. Anaemia increased the transfusion risk (RR 4.44, 95% CI 3.90 to 5.06, P < 0.001) and postoperative intensive care unit (ICU) admission (RR 1.09, 95% CI 1.04 to 1.16, P = 0.001).

CONCLUSIONS

Four out of 10 patients had anaemia. These patients had an increased risk of adverse postoperative outcomes. Comprehension of the magnitude and impact of anaemia is essential to establish interventions in low-resource scenarios to optimise the patient's journey.

STUDY REGISTRATION

Institutional Review Board Registration number 40522820000005327 (Brazilian CEP/CONEP System, available in https://plataformabrasil.saude.gov.br/).

Nonanemic Iron Deficiency in Cardiac Surgery: A Retrospective Observational Study

OBJECTIVES

Anemia and iron deficiency in patients having cardiac surgery increases their perioperative risk. Nonanemic iron deficiency (NAID) in this group is less well-described. We aimed to investigate the incidence and outcomes of patients with NAID undergoing cardiac surgery.

DESIGN

Retrospective observational study.

SETTING

A single, tertiary referral center.

PARTICIPANTS

Adult patients who were preassessed and underwent cardiac surgery during the study period had data collected. We enrolled 537 patients enrolled and divided them into 4 groups according to hemoglobin and ferritin: NAID, nonanemic iron replete, iron-deficiency anemia (IDA), and non-iron-deficiency anemia.

INTERVENTIONS

This study was not interventional, but assessed the impact of anemia and iron deficiency on patient outcomes.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was the incidence of NAID. Secondary outcomes included the number of patients who became anemic awaiting surgery, allogeneic transfusion burden, length of stay, postoperative complications, and death. 179 of 537 patients (33.3%) had NAID. Seventeen patients (9.5%) became anemic in the NAID group compared with 7 (3.3%) in the nonanemic iron replete group while awaiting for surgery (p = 0.02). Patients with NAID were more likely to receive allogeneic transfusions (33% vs 23%; p = 0.04) and had poorer recovery of hemoglobin at follow-up (13.2 ± 1.46 g/dL vs 13.9 ± 1.46 g/dL; p < 0.001).

CONCLUSIONS

NAID is common and can lead to progression to anemia and increased transfusion. Iron replacement should be considered in patients with NAID in the preoperative setting. A prospective interventional trial is required to demonstrate the benefit of being iron replete.

Impact of introduction of a goal directed transfusion strategy in a patient blood management program: A single cardiac surgery centre experience

BACKGROUND

The aim of this retrospective and observational study was to analyse the impact of the introduction of a goal directed transfusion (GDT) strategy based on a viscoelastic test (ROTEM®) and specific procoagulant products in a patient blood management (PBM) Program on blood product use and perioperative bleeding in a single cardiac surgery centre.

STUDY DESIGN AND METHODS

Patient population underwent cardiac surgery from 2011 to 2021 was divided in two groups based on PBM protocol used (G#11-14, years 2011-2014, G#15-21, years 2015-2021) and compared for the following variables: intraoperative and postoperative transfusions of packed red blood cell and any procoagulant products, postoperative drain blood loss volume and rate of re-exploration surgery. The second program was defined after the introduction of a GDT protocol based on viscoelastic tests and specific procoagulant products.

RESULTS

After the introduction of a GDT protocol, about 80% less amongst patients were transfused with fresh frozen plasma and any procoagulant product (p < 0.001 for both phases). Moreover, similar results were obtained with PRBC transfusions (p < 0.001) and drain blood loss volume (p = 0.006) in the postoperative phase. The main factors affecting the use of any procoagulant and PBRC transfusion in the multivariate logistic regression analysis was Group (2 versus 1, OR 0.207, p < 0.001) and preoperative haemoglobin (OR 0.728, p < 0.001), respectively.

DISCUSSION

In our experience, a GDT strategy for the diagnosis and treatment of the coagulopathy in patients undergone cardiac surgery led to a significant reduction in bleeding and transfusion.

The Relationship Between Transfusion in Cardiac Surgery Patients and Adverse Outcomes

OBJECTIVES

To understand if red blood cell (RBC) transfusions are independently associated with a risk of mortality, prolonged intubation, or infectious, cardiac, or renal morbid outcomes.

DESIGN

A retrospective review.

SETTING

A single-institution university hospital.

PARTICIPANTS

A total of 2,458 patients undergoing coronary bypass artery graft and/or valvular surgery from July 2014 through January 2018.

INTERVENTIONS

No interventions were done.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was the occurrence of an adverse event or prolonged intubation. Infectious, cardiac, and renal composite outcomes were also defined. These composites, along with mortality, were analyzed individually and then combined to form the "any adverse events" composite. Preoperative demographic and intraoperative parameters were analyzed as univariate risk factors for adverse outcomes. Logistic regression was used to screen variables, with a p value criterion of p < 0.05 for entry into the model selection procedure. A backward selection algorithm was used with variable entry and retention criteria of p < 0.05 to select the final multivariate model. Multivariate logistic regression models were used to determine whether there was an association between the volume of RBC transfusion and the defined adverse event after adjusting for covariates. A p value < 0.01 was considered statistically significant in the final model of each aim to adjust for multiple comparisons. The final logistic models for each of the following outcomes indicate an increased risk of that outcome per each additional unit of RBC transfused. For prolonged intubation, the odds ratio (OR) was 1.493 (p < 0.0001), OR = 1.358 (p < 0.0001) for infectious composite outcomes, OR = 1.247 (p < 0.0001) for adverse renal outcomes, and OR = 1.467 (p < 0.0001) for any adverse event.

CONCLUSIONS

The authors demonstrated a strong independent association between RBC transfusion volume and adverse outcomes after cardiac surgery. Efforts should be undertaken, such as preoperative anemia management and control of coagulopathy, in order to minimize the need for RBC transfusion.

Identification and management of preoperative anaemia in adults: A British Society for Haematology Guideline update

This updated British Society for Haematology guideline provides an up-to-date literature review and recommendations regarding the identification and management of preoperative anaemia. This includes guidance on thresholds for the diagnosis of anaemia and the diagnosis and management of iron deficiency in the preoperative context. Guidance on the appropriate use of erythropoiesis-stimulating agents and preoperative transfusion is also provided.

Associations Between Nonanemic Iron Deficiency and Postoperative Outcomes in Cardiac Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

Preoperative screening for iron deficiency is a part of patient blood management protocols. This systematic review, meta-analysis, and meta-regression reviews the association between nonanemic iron deficiency and postoperative outcomes in patients undergoing cardiac surgery. We aimed to determine whether preoperative screening for nonanemic iron deficiency should be recommended in patients undergoing cardiac surgery.

METHODS

Electronic databases MEDLINE (Ovid), Embase (Ovid), and Scopus were searched from inception until December 9, 2022. Studies were considered for inclusion if they (1) used an observational study design; (2) enrolled adult patients undergoing cardiac surgery; and (3) included an iron-deficient and iron-replete group, defined using serum ferritin and/or transferrin saturation. The primary outcome was the length of acute hospital stay. Secondary outcomes included length of intensive care unit stay, requirement for allogeneic red blood cell transfusion, number of red blood cell units transfused, days alive and at home at postoperative days 30 and 90, all-cause postoperative complications, postoperative infection, mortality, and hospital readmission. Meta-regression was performed to assess the effects of study and patient-level factors on the associations between nonanemic iron deficiency and specific outcomes. Individual study quality was assessed using the Risk of Bias in Non-Randomized Studies of Exposures (ROBINS-E) tool. The Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) framework was used to determine the quality of evidence for each outcome.

RESULTS

Eight studies (2683 patients) were included. No significant association was observed between nonanemic iron deficiency and any of the primary or secondary outcomes except for an increased requirement for allogeneic red blood cell transfusion (odds ratio [OR], 1.39 [95% confidence interval, CI, 1.16-1.68; P < .001; I2 2.8%]). Meta-regression did not identify any potential sources of heterogeneity to explain variation in individual study results. The quality of evidence was rated as "low" or "very low" for all outcomes.

CONCLUSIONS

Few high-quality studies are available to assess associations between nonanemic iron deficiency and outcomes after cardiac surgery. Acknowledging these limitations, the presence of preoperative nonanemic iron deficiency was not associated with a change in the primary outcome of length of hospital stay, or any patient-centered secondary outcome compared to those without iron deficiency. There was an association with increased requirement for allogeneic red blood cell transfusion, but this did not impact the reported patient-centered outcomes.

The Impact of Silent Liver Disease on Hospital Length of Stay Following Isolated Coronary Artery Bypass Grafting Surgery

Objectives: Risk assessment models for cardiac surgery do not distinguish between degrees of liver dysfunction. We have previously shown that preoperative liver stiffness is associated with hospital length of stay following cardiac surgery. The authors hypothesized that a liver stiffness measurement (LSM) ≥ 9.5 kPa would rule out a short hospital length of stay (LOS < 6 days) following isolated coronary artery bypass grafting (CABG) surgery. Methods: A prospective observational study of one hundred sixty-four adult patients undergoing non-emergent isolated CABG surgery at a single university hospital center. Preoperative liver stiffness measured by ultrasound elastography was obtained for each participant. Multivariate logistic regression models were used to assess the adjusted relationship between LSM and a short hospital stay. Results: We performed multivariate logistic regression models using short hospital LOS (<6 days) as the dependent variable. Independent variables included LSM (< 9.5 kPa, ≥ 9.5 kPa), age, sex, STS predicted morbidity and mortality, and baseline hemoglobin. After adjusting for included variables, LSM ≥ 9.5 kPa was associated with lower odds of early discharge as compared to LSM < 9.5 kPa (OR: 0.22, 95% CI: 0.06-0.84, p = 0.03). The ROC curve and resulting AUC of 0.76 (95% CI: 0.68-0.83) suggest the final multivariate model provides good discriminatory performance when predicting early discharge. Conclusions: A preoperative LSM ≥ 9.5 kPa ruled out a short length of stay in nearly 80% of patients when compared to patients with a LSM < 9.5 kPa. Preoperative liver stiffness may be a useful metric to incorporate into preoperative risk stratification.

Risk factors and clinical prediction models for prolonged mechanical ventilation after heart valve surgery

OBJECTIVES

Prolonged mechanical ventilation (PMV) is a common complication following cardiac surgery linked to unfavorable patient prognosis and increased mortality. This study aimed to search for the factors associated with the occurrence of PMV after valve surgery and to develop a risk prediction model.

METHODS

The patient cohort was divided into two groups based on the presence or absence of PMV post-surgery. Comprehensive preoperative and intraoperative clinical data were collected. Univariate and multivariate logistic regression analyses were employed to identify risk factors contributing to the incidence of PMV. Based on the logistic regression results, a clinical nomogram was developed.

RESULTS

The study included 550 patients who underwent valve surgery, among whom 62 (11.27%) developed PMV. Multivariate logistic regression analysis revealed that age (odds ratio [OR] = 1.082, 95% confidence interval [CI] = 1.042-1.125; P < 0.000), current smokers (OR = 1.953, 95% CI = 1.007-3.787; P = 0.047), left atrial internal diameter index (OR = 1.04, 95% CI = 1.002-1.081; P = 0.041), red blood cell count (OR = 0.49, 95% CI = 0.275-0.876; P = 0.016), and aortic clamping time (OR = 1.031, 95% CI = 1.005-1.057; P < 0.017) independently influenced the occurrence of PMV. A nomogram was constructed based on these factors. In addition, a receiver operating characteristic (ROC) curve was plotted, with an area under the curve (AUC) of 0.782 and an accuracy of 0.884.

CONCLUSION

Age, current smokers, left atrial diameter index, red blood cell count, and aortic clamping time are independent risk factors for PMV in patients undergoing valve surgery. Furthermore, the nomogram based on these factors demonstrates the potential for predicting the risk of PMV in patients following valve surgery.

Adjusting Current Hemoglobin Thresholds: A Way to Improve Outcome in Women Undergoing Major Surgery

Background/Objective: In the perioperative setting, a suboptimal total hemoglobin (Hb) mass puts women and men at an unreasonable disadvantage. Anemia is an independent risk factor for transfusion, postoperative complications, and mortality. The Hb cut-off value for women was set at <12.0 g/dL by the World Health Organization (WHO) and has been rigorously debated for decades. The aim of this study was to elucidate the risk for postoperative complications in female patients with Hb levels < 12.0, 12.0-12.9, and ≥13.0 g/dL. Material and Methods: Single-center retrospective analysis of female patients undergoing major surgery. Results: In total, 6,516 patients ≥18 years of age had major surgery between 2018 and 2019 and 2,446 female patients were included in analysis. Mean age was 67.4 ± 16.6, 66.4 ± 15.6, and 64.5 ± 15.5 years in female patients with preoperative Hb levels <12.0, 12.0-12.9 and ≥13.0 g/dL, respectively. The transfusion rate of red blood cells (RBCs) was significantly higher in female patients with Hb <12.0 g/dL (53%) and with Hb 12.0-12.9 g/dL (31%) compared to female patients ≥13.0 g/dL (22%). Rates of pneumonia, acute kidney injury, and sepsis were significantly higher in patients with Hb <12.0 and 12.0-12.9 g/dL compared to patients with Hb ≥13.0 g/dL. Total length of hospital stay was significantly longer in female patients with Hb <12.0 g/dL than patients with Hb 12.0-12.9 g/dL and Hb ≥13.0 g/dL (10 days vs. 8 days). Conclusion: Taken together, our data show that Hb values below 12.9 g/dL are associated with increased probability of RBC transfusions and increased risk of postoperative complications. In addition, our results indicate that postoperative outcomes for women might be optimized by increasing cut-off values for anemia. The call to revise the anemia threshold for women by the WHO can no longer be disregarded.

Optimizing the transfusion strategy in surgical patients in a Lebanese university hospital

BACKGROUND AND PURPOSE

Our aim was to analyze factors that influence transfusion requirements in surgical patients in order to achieve a transfusion-saving strategy.

METHODS

Data was collected from patient's files at the Notre Dame de Secours-Jbeil University Hospital Center between January 2017 and June 2019. Selection was made for 400 patients who had undergone surgery and required transfusion. The studied variables were age, sex, and type of surgery whether planned or urgent with its expected level of bleeding. The presence of chronic anemia, coronary artery disease, values of hemoglobin and hematocrit before and after transfusion, iron status preoperatively, and post-operation complications were also noted.

RESULTS

The analysis of 400 transfused surgical patients showed that the mean age was 62 ± 18 years with 52.5% women and 47.5% men. In 82.3% of patients, surgical bleeding was expected, 77.8% of surgeries were scheduled, and 22.3% were urgent. Fifty-two percent of patients were known to have coronary artery disease. Orthopedic (35%) and cardiothoracic (29.5%) surgeries had the highest transfusion rate. Among all patients, only 106 patients (26.5%) underwent a preoperative iron workup. The pre-transfusion levels of hemoglobin were 9.9 ± 0.6 and hematocrit of 29.7 ± 1.9. 26.3% of patients had a post-transfusion complication. On the other hand, 19.5% of women and 20% of men were already anemic when admitted to the hospital. Anemic women required 7.6 times more transfusions than non-anemic, while anemic men required 12.38 times more transfusions than non-anemic men. Age, presence of coronary artery disease, and chronic anemia have been found to be factors increasing the risk of post-transfusion complications. Finally, urgent and unplanned surgeries are 2.9 times more likely to cause post-transfusion complications.

CONCLUSION

This study therefore confirms that anemic patients are more likely to receive perioperative blood transfusions. Consequently, in order to reduce blood transfusion and its complications, it would be beneficial primarily to diagnose and treat anemia preoperatively. Other transfusion-saving strategies could also be useful in the setting of surgical bleeding, such as the use of tranexamic acid and different autologous transfusion methods like the cell saver.

Preoperative hemoglobin thresholds for survival equity in women and men

Anemia affects humans throughout life, and is linked to higher morbidity and mortality. Unclear is whether hemoglobin values are equivalent between women and men. This study evaluates the association of preoperative hemoglobin levels with in-hospital mortality and estimates thresholds for survival equity between men and women. All adult patients undergoing surgery between 2010 and 2019 from 14 German hospitals were included in the study. Thresholds for survival equity were determined with generalized additive models. In total, 842,130 patients with a median in-hospital follow-up time of 7 days were analyzed. During follow-up 20,370 deaths occurred. Preoperative hemoglobin stratified in-hospital mortality (log-rank test p < 0.001) and was associated with mortality independently of demographic risk, surgical risk and health status. For each 1 g/dL reduction in preoperative hemoglobin, the odds of mortality increased by a factor of 1.22 (95% CI 1.21-1.23, p < 0.001). A preoperative hemoglobin threshold of 10.5 g/dL reflected equivalent risk for both male and female patients. Hemoglobin levels below 10.5 g/dL had higher risk of mortality for women than for men. The findings from this study aid evidence-based thresholds, inform anemia management and promote equitable care, thus enhancing patient outcomes.

The additive effects of anaemia and transfusion on long-term survival after coronary artery bypass surgery

OBJECTIVES

To compare the independent and combined effects of anaemia and red blood cell transfusion on late survival after isolated coronary artery bypass grafting.

METHODS

Retrospective analysis of 5243 consecutive patients undergoing primary isolated coronary artery bypass grafting, performed from 2000 to 2015, in a Portuguese Academic Hospital. We identified 1649 patients with preoperative anaemia (A+) and 1422 patients who received a perioperative transfusion (T+)-the 4 possible combinations allowed for the creation of 4 subgroups (A-/T-, A-/T+, A+/T- and A+/T+). The primary endpoint was all-cause mortality at 10 years. We employed inverse probability weighting to control for confounding variables.

RESULTS

Thirty-one percent of the patients had preoperative anaemia, and 27.0% had at least one packed red blood cell transfusion. Inverse probability weighting was effective in eliminating differences in all significant baseline characteristics. The primary endpoint of all-cause mortality at 10 years occurred in 568 patients (20.5%) in the A-/T- group, as compared with 204 (24.4%) in the A-/T+ group (hazard ratio, 1.14; 95% confidence interval, 1.00 to 1.31; P = 0.053), 358 (33.8%) in the A+/T- group (hazard ratio, 1.53; 95% confidence interval, 1.38 to 1.71; P < 0.001), 254 (43.6%) in the A+/T+ group (hazard ratio, 2.25; 95% confidence interval, 1.97 to 2.56; P < 0.001).

CONCLUSIONS

This longitudinal, population-level study emphasizes the adverse long-term outcomes of preoperative anaemia and perioperative red blood cell transfusion. It stresses the importance of an evidence-based, multimodal and multidisciplinary approach to conserving blood resources and optimizing outcomes in patients at high risk for transfusion.

Preoperative anemia and anemia treatment in cardiac surgery: a systematic review and meta-analysis

PURPOSE

We aimed to conduct a systematic review and meta-analysis to assess the effects of anemia and anemia severity on patient outcomes in cardiac surgery and determine whether preoperative treatments confer postoperative benefit.

SOURCE

We searched four international databases for observational and randomized studies published until 1 October 2022. Study quality was assessed via Newcastle-Ottawa scores and the Cochrane Risk-of-Bias 2 tool and certainty of evidence was rated with the Grading of Recommendations, Assessment, Development and Evaluations approach. We conducted random-effects meta-analyses for our primary outcome of mortality, for secondary outcomes including length of stay (LOS) in the hospital and intensive care unit, and for postsurgical complications. As part of a secondary analysis, we analyzed short-term preoperative anemia treatments and conducted trial sequential analysis of randomized trials to assess the efficacy of these treatment programs.

PRINCIPAL FINDINGS

We included 35 studies (159,025 patients) in our primary meta-analysis. Preoperative anemia was associated with increased mortality (odds ratio [OR], 2.5; 95% confidence interval [CI], 2.2 to 2.9; P < 0.001, high certainty). Study-level meta-regression revealed lower hemoglobin levels and studies with lower proportions of male patients to be associated with increased risk of mortality. Preoperative anemia was also associated with an increase in LOS and postsurgical complications. Our secondary analysis (seven studies, 1,012 patients) revealed short-term preoperative anemia treatments did not significantly reduce mortality (OR, 1.1; 95% CI, 0.65 to 1.9; P = 0.69). Trial sequential analysis suggested that there was insufficient evidence to conclude if treatment programs yield any benefit or harm.

CONCLUSIONS

Preoperative anemia is associated with mortality and morbidity after cardiac surgery. More research is warranted to test the efficacy of current anemia treatment programs.

STUDY REGISTRATION

PROSPERO (CRD42022319431); first submitted 17 April 2023.

Sex-Specific Associations Between Preoperative Hemoglobin and Outcomes After Major Noncardiac Surgery: A Retrospective Cohort Study

BACKGROUND

Preoperative anemia is an established risk factor for morbidity and mortality after surgery. Men and women have different hemoglobin concentrations and are at different risks of postoperative complications. However, sex-stratified analysis on the association between preoperative hemoglobin and outcomes after noncardiac surgery has been limited in previous studies.

METHODS

This was a retrospective cohort study of adult patients undergoing elective major noncardiac surgery in a large academic hospital. The primary outcome was a collapsed composite of postoperative mortality or cardiovascular, renal, pulmonary, and infectious complications during hospitalization. Sex-specific univariable associations between preoperative hemoglobin and the composite outcome were visualized using moving-average and cubic-spline smoothing plots. Multivariable regression models adjusting for patient demographics, comorbidities, medication uses, laboratory tests, and anesthesia/surgery features were used to estimate confounder-adjusted associations. Restricted cubic spline and piecewise linear functions were used to assess the possible nonlinear relationships between preoperative hemoglobin and the outcomes. The interaction between patient sex and hemoglobin on outcomes was assessed using a likelihood-ratio test.

RESULTS

We included 22,550 patients, with 6.7% (622 of 9268) of women and 9.7% (1293 of 13,282) of men developing the primary outcome. Lower preoperative hemoglobin was associated with a higher incidence of the primary composite outcome in both men and women. Nonlinearity for the association was not statistically significant in either women ( P = .539) or men ( P = .165). The multivariable-adjusted odds ratios per 1 g/dL increase in hemoglobin were 0.93 (95% confidence interval [CI], 0.87-0.98; P = .013) for women and 0.94 (95% CI, 0.90-0.97; P < .001) for men, with no interaction by sex ( Pinteraction = .923). No hemoglobin thresholds were confirmed at which the associations with the primary outcome changed significantly.

CONCLUSIONS

Low preoperative hemoglobin was associated with a higher risk of complications or mortality after elective noncardiac surgery in both men and women. No differences in the strength of associations between sexes were found. Further studies are needed to assess whether these associations are linear or there are sex-specific thresholds of preoperative hemoglobin concentrations below which postoperative risks begin to increase.

Determining sex-specific preoperative haemoglobin levels associated with intraoperative red blood cell transfusion in cardiac surgery: a retrospective cohort study

BACKGROUND

Anaemic cardiac surgery patients are at greater risk of intraoperative red blood cell transfusion. This study questions the application of the World Health Organization population-based anaemia thresholds (haemoglobin <120 g L-1 in non-pregnant females and <130 g L-1 in males) as appropriate preoperative optimisation targets for cardiac surgery.

METHODS

A retrospective cohort study was conducted on adults ≥18 yr old undergoing cardiopulmonary bypass surgery. Logistic regression was applied to define sex-specific preoperative haemoglobin concentrations with reduced probability of intraoperative red blood cell transfusion for cardiac surgery patients.

RESULTS

Data on 4384 male and 1676 female patients were analysed. Binarily stratified multivariable logistic regression odds of receiving intraoperative red blood cell transfusion increased in cardiac surgery patients >45 yr old (odds ratio [OR] 1.84; 95% confidence interval [CI] 1.33-2.55), surgery urgency <30 days (OR 2.03; 95% CI 1.66-2.48), combined coronary artery bypass grafting and valve surgery, or other surgery types (OR 2.24; 95% CI 1.87-2.67), and female sex (OR 1.92; 95% CI 1.62-2.28). The odds decreased by 8.4% with each 1 g L-1 increase in preoperative haemoglobin (OR 0.92; 95% CI 0.91-0.92). Logistic regression predicted females required a preoperative haemoglobin concentration of 133 g L-1 and males 127 g L-1 to have a 15% probability of intraoperative transfusion.

CONCLUSIONS

The World Health Organization female anaemia threshold of haemoglobin <120 g L-1 disproportionately disadvantages female cardiac surgery patients. A preoperative haemoglobin concentration ≥130 g L-1 in adult cardiac surgery patients would minimise their overall probability of intraoperative red blood cell transfusion to <15%.

Principles of minimize bleeding and the transfusion of blood and its components in operated patients - surgical aspects

One of the target of perioperative tratment in surgery is decreasing intraoperative bleeding, which increases the number of perioperative procedures, mortality and treatment costs, and also causes the risk of transfusion of blood and its components. Trying to minimize the blood loss(mainly during the operation) as well as the need to transfuse blood and its components (broadly understood perioperative period) should be standard treatment for a patient undergoing a procedure. In the case of this method, the following steps should be taken: 1) in the preoperative period: identyfication of risk groups as quickly as possible, detecting and treating anemia, applying prehabilitation, modyfying anticoagulant treatment, considering donating one's own blood in some patients and in selected cases erythropoietin preparations; 2) in the perioperative period: aim for normothermia, normovolemia and normoglycemia, use of surgical methods that reduce bleeding, such as minimally invasive surgery, high-energy coagulation, local hemostatics, prevention of surgical site infection, proper transfusion of blood and its components if it occurs; 3) in the postoperative period: monitor the condition of patients, primarily for the detection of bleeding, rapid reoperation if required, suplementation (oral administration preferred) nutrition with microelements (iron) and vitamins, updating its general condition. All these activities, comprehensively and in surgical cooperation with the anesthesiologist, should reduce the blood loss and transfusion of blood and its components.

Association between preoperative anemia and postoperative short-term outcomes in patients undergoing colorectal cancer surgery - a propensity score matched retrospective cohort study

BACKGROUND

Based on previous studies which failed to analyze important confounding variables, the association between preoperative anemia and outcomes of patients who underwent colorectal cancer (CRC) surgery has not been clearly demonstrated. This study aimed to investigate the relationship between preoperative anemia and short-term outcomes in patients with CRC.

METHODS

Data from a retrospective collective database of patients who underwent CRC surgery at our hospital between September 1, 2019 and September 30, 2021 were retrieved and analyzed, and the short-term postoperative outcomes of anemic (hemoglobin < 120 g dL- 1 for female, hemoglobin < 130 g dL- 1 for male) and non-anemic patients were analyzed, using a 1:1 propensity score matching (PSM) analysis.

RESULTS

After excluding some cases, the remaining 1894 patients had complete data available for analysis. The incidence of preoperative anemia was 39.8% (754/1894). Before PSM, preoperative anemia patients had a higher risk of major morbidity than non-anemia patients (27.2% vs. 23.1%, odds ratio [OR] 1.245, 95% confidence interval [CI] 1.008-1.538, P = 0.042). After PSM was performed in the cohort, 609 patients remained in the anemic and non-anemic groups. The incidence of major morbidity (25.8% vs. 24.0%, OR 1.102, 95% CI 0.849-1.429, P = 0.446) between anemic and non-anemic patients was comparable. No significant difference was found between the anemic and non-anemic groups in postoperative length of stay (8.0 [6.0-12.0] vs. 8.0 [7.0-11.0], P = 0.311). The sensitivity analysis results were in accordance with the primary outcome. Furthermore, we did not ascertain any discernible correlation between the extent of anemia and significant major morbidity.

CONCLUSIONS

Compared with preoperative non-anemia, anemia status does not seem to be associated with major morbidity in patients with CRC surgery. It is noteworthy that, anemia is insufficient as a solitary risk factor and may be a better marker of poor health resulting from multiple factors.

TRIAL REGISTRATION

Registration Authority: Chinese Clinical Trial Registry; Registration number and date: ChiCTR2100049696, 08/08/2021; Principal investigator: Ting Yan; Link to trial registry: http://www.chictr.org.cn/showproj.aspx?proj=131698 ; .

Patient blood management programmes: keeping the ball rolling

Patient blood management programmes have been endorsed by the World Health Organization and multiple medical societies. It seems important to review the progress and results of patient blood management programmes so necessary modifications or new initiatives can be added to achieve their major goals. In this issue of the British Journal of Anaesthesia, Meybohm and colleagues show that a nationwide patient blood management programme had an impact and was potentially cost-effective in centres that previously utilised large amounts of allogeneic blood transfusions. Before implementing a programme, each institution might need to identify the area(s) of deficiency with respect to established patient blood management methods, which will warrant specific focus in subsequent clinical practice reviews.

[Iron deficiency in cardiac surgery patients and the possibility of its correction at the preoperative stage]

Among cardio-surgical patients, the prevalence of iron deficiency conditions reaches 70 %, and anemia is detected in less than 50% cases. Meanwhile, both anemia and latent iron deficiency are risk factors for adverse outcomes in cardio-surgical patients. These conditions are associated with a high frequency and greater volume of blood transfusions as well as with a longer stay in the hospital. Timely diagnosis and correction of iron deficiency, regardless of the presence of anemia, are mandatory at the stage of preoperative preparation. The use of oral iron medicines is limited by their low efficacy in this category of patients and a high risk of adverse events. Intravenous iron medicines have a high potential for correcting iron deficiency, and their efficacy and safety have been previously demonstrated. Administration of ferric carboxymaltose has proved beneficial in studies on iron deficiency correction in cardiological and cardio-surgical patients. In these patients, ferric carboxymaltose improved the dynamics of ferritin and hemoglobin, reduced the risk of blood transfusion, and decreased the duration of stay in the hospital. Preoperative intravenous administration of ferric carboxymaltose to cardio-surgical patients can improve clinical outcomes and the cost effectiveness of cardiac surgery.

Prognostic Implication of Preoperative Anemia in Redo Cardiac Surgery: A Single-Center Propensity-Matched Analysis

Preoperative anemia has been associated with increased morbidity and mortality after cardiac surgery, but little is known about its prognostic value in the setting of redo procedure. A retrospective, observational cohort study of prospectively collected data was undertaken on 409 consecutive patients referred for redo cardiac procedures between January 2011 and December 2020. The EuroSCORE II calculated an average mortality risk of 25.7 ± 15.4%. Selection bias was assessed with the propensity-adjustment method. The prevalence of preoperative anemia was 41%. In unmatched analysis, significant differences between the anemic and nonanemic groups emerged in the risk for postoperative stroke (0.6% vs. 4.4%, p = 0.023), postoperative renal dysfunction (29.7% vs. 15.6%, p = 0.001), a need for prolonged ventilation (18.1% vs. 7.2%, p = 0.002), and high-dosage inotropes (53.1% vs. 32.9%, p < 0.001) along with both length of ICU and hospital stay (8.2 ± 15.9 vs. 4.3 ± 5.4 days, p = 0.003 and 18.8 ± 17.4 vs. 14.9 ± 11.1, p = 0.012). After propensity matching (145 pairs), preoperative anemia was still significantly associated with postoperative renal dysfunction, stroke, and the need for high-dosage inotrope cardiac morbidity. Preoperative anemia is significantly associated with acute kidney injury, stroke, and the need for high-dosage inotropes in patients referred for redo procedures.

Evaluating Preoperative Intravenous Iron and Erythropoietin Treatment and Outcomes in Cardiac Surgery Patients

Background

Anemia is more common in cardiac surgery patients than in other people. Severe anemia before cardiac surgery strongly predicts blood transfusion.

Objectives

This study aimed to evaluate the outcomes of Intravenous (IV) iron and erythropoietin (EPO) injection preoperatively in anemic patients waiting for coronary artery bypass graft (CABG) surgery.

Methods

This cross-sectional study was performed between May to December 2020 at Masih Daneshvari hospital in Tehran, Iran. Anemia was described according to the WHO definition (Hb < 130 g/L in men). The study was designed in two groups of men CABG patients. Hematocrit level, platelet count, partial thromboplastin time, international normalized ratio, prothrombin time before surgery, red blood cells (RBCs) transfusion, as well as plasma and platelet units' transfusion during surgery and at the time of hospitalization were obtained from patient's files. The length of stay in the hospital and the consequences, including infection, stroke and heart attack, and mortality, were also obtained from the patient's files and recorded in the checklists. Pearson's chi-squared test, Fisher's exact test, independent samples t-test, univariate logistic regression, and odds ratio (OR) were used. All statistical analyses were performed by the SPSS software version 21. The significance level in this study was considered 0.05.

Results

In this study, the data of 64 patients were gathered, among whom 16 (25%) were injected with IV iron and EPO, and the remaining 48 (75%) did not receive any medications for stimulating erythropoiesis. The mean age of patients was 64.05 ± 8.21 years, with an age range of 51 - 91 years. Infection (P = 0.258) and mortality rate (P = 0.440) in the two groups of injection and non-injection did not show a statistically significant difference. The duration of the clamp at the time of surgery (r = 0.699, P = 0.001) and the duration of hospitalization (r = 0.399, P = 0.023) had statistically significant positive relationships with the pump duration. Red blood cell consumption in the injection and non-injection groups was 2.50 ± 2.07 and 2.90 ± 1.80 (P = 0.469), respectively.

Conclusions

Infection (P = 0.258), mortality rate (P = 0.440), and RBC utilization (P = 0.469) in the two groups of injection and non-injection were not significantly different.

Multidisciplinary paper on patient blood management in cardiothoracic surgery in the UK: perspectives on practice during COVID-19

The coronavirus (COVID-19) pandemic disrupted all surgical specialties significantly and exerted additional pressures on the overburdened United Kingdom (UK) National Health Service. Healthcare professionals in the UK have had to adapt their practice. In particular, surgeons have faced organisational and technical challenges treating patients who carried higher risks, were more urgent and could not wait for prehabilitation or optimisation before their intervention. Furthermore, there were implications for blood transfusion with uncertain patterns of demand, reductions in donations and loss of crucial staff because of sickness and public health restrictions. Previous guidelines have attempted to address the control of bleeding and its consequences after cardiothoracic surgery, but there have been no targeted recommendations in light of the recent COVID-19 challenges. In this context, and with a focus on the perioperative period, an expert multidisciplinary Task Force reviewed the impact of bleeding in cardiothoracic surgery, explored different aspects of patient blood management with a focus on the use of haemostats as adjuncts to conventional surgical techniques and proposed best practice recommendations in the UK.

Haemoglobin levels and outcomes of subgroups of patients with pre-operative anaemia based on red cell size: A retrospective cohort study

BACKGROUND

Pre-operative anaemia is common and associated with adverse outcomes. We hypothesised that pre-operative anaemia would be evident more than 1 month pre-operatively, and that peri-operative changes in haemoglobin and post-operative outcomes differed between red cell size-based subsets of anaemia.

METHODS

A retrospective single-centre cohort study, including all patients 18 years and older undergoing their first surgery at Landspitali between January 2006 and December 2018 with available measurement of haemoglobin (Hb) within 30 days preceding surgery. Clinical data were compared between patients with subgroups of anaemia classified by mean corpuscular volume (MCV) into microcytic (MCV < 80 fl), normocytic (MCV 80-100 fl), and macrocytic (MCV > 100 fl) anaemia. The development of haemoglobin measurements from a nationwide database was plotted from 1 year pre-operatively to 2 years post-operatively.

RESULTS

Of 40,979 patients, 10,505 (25.6%) had pre-operative anaemia, of which 1089 (10.4%) had microcytic anaemia, 9243 (88.0%) had normocytic anaemia, and 173 (1.6%) had macrocytic anaemia. Patients within all subgroups of pre-operative anaemia had a higher degree of comorbidity and frailty burden and a low haemoglobin evident for more than 100 days pre-operatively and similar changes post-operatively. Post-operative prolonged recovery of haemoglobin was slower for macrocytic anaemia than other types of anaemia. All groups of patients with anaemia had a higher incidence of 30-day mortality, acute kidney injury, and rate of readmission compared with patients without anaemia.

CONCLUSIONS

Pre-operative anaemia is evident long prior to the procedure and its association with worse outcomes is similar regardless of red cell size.

Effect of Preoperative Administration of Intravenous Ferric Carboxymaltose in Patients with Iron Deficiency Anemia after Off-Pump Coronary Artery Bypass Grafting: A Randomized Controlled Trial

Patients scheduled for cardiac surgery often have anemia and iron deficiency. We investigated the effect of the preoperative administration of intravenous ferric carboxymaltose (IVFC) in patients with iron deficiency anemia (IDA) who were due to undergo off-pump coronary artery bypass grafting (OPCAB). Patients who were due to undergo elective OPCAB between February 2019 and March 2022 who had IDA (n = 86) were included in this single center, randomized, parallel-group controlled study. The participants were randomly assigned (1:1) to receive either IVFC or placebo treatment. Postoperative hematologic parameters [hemoglobin (Hb), hematocrit, serum iron concentration, total iron-binding capacity, transferrin saturation, transferrin concentration, and ferritin concentration] and the changes in these parameters during the follow-up period were the primary and secondary outcomes, respectively. The tertiary endpoints were early clinical outcomes, such as the volume of mediastinal drainage and the need for blood transfusions. IVFC treatment significantly reduced the need for red blood cell (RBC) and platelet transfusions. Despite receiving fewer RBC transfusions, patients in the treatment group had higher levels of Hb, hematocrit, and serum iron and ferritin concentrations during weeks 1 and 12 after surgery. No serious adverse events occurred during the study period. Preoperative IVFC treatment in patients with IDA undergoing OPCAB improved the values of the hematologic parameters and iron bioavailability. Therefore, is a useful strategy for stabilizing patients prior to OPCAB.

Perioperative Optimization of the Cardiac Surgical Patient

Perioperative optimization of cardiac surgical patients is imperative to reduce complications, utilize health care resources efficiently, and improve patient recovery and quality of life. Standardized application of evidence-based best practices can lead to better outcomes. Although many practices should be applied universally to all patients, there are also opportunities along the surgical journey to identify patients who will benefit from additional interventions that will further ameliorate their recovery. Enhanced recovery programs aim to bundle several process elements in a standardized fashion to optimize outcomes after cardiac surgery. A foundational concept of enhanced recovery is attaining a better postsurgical end point for patients, in less time, through achievement and maintenance in their greatest possible physiologic, functional, and psychological state. Perioperative optimization is a broad topic, spanning multiple phases of care and involving a variety of medical specialties and nonphysician health care providers. In this review we highlight a variety of perioperative care topics, in which a comprehensive approach to patient care can lead to improved results for patients, providers, and the health care system. A particular focus on patient-centred care is included. Although existing evidence supports all of the elements reviewed, most require further improvements in implementation, as well as additional research, before their full potential and usefulness can be determined.

Treatment Strategies in Anemic Patients Before Cardiac Surgery

Both preoperative anemia and the transfusion of red blood cells have been associated with increased morbidity and mortality after cardiac surgery. To reduce the need for blood transfusion during surgery and improve patient outcomes, patient blood management programs have been developed. A primary focus of patient blood management in the preoperative period is the identification, diagnosis, and treatment of preoperative anemia, as anemia is associated with an increased risk of preoperative blood transfusion. In this narrative review, the authors focus on the laboratory screening of anemia before surgery and the evidence and limitations of different treatment strategies in anemic patients scheduled for cardiac surgery. To accurately correct preoperative anemia, the timely detection and definition of the etiology of anemia before elective cardiac surgery are crucial. Multiple randomized studies have been performed using preoperative iron supplementation and/or administration of erythropoiesis-stimulating agents in patients undergoing cardiac surgery. Although preoperative iron substitution in patients with iron deficiency is recommended, the evidence of its effectiveness is limited. In patients with nonpure iron deficiency anemia, combined therapy with erythropoiesis-stimulating agents and intravenous iron is recommended. Combined therapy might effectively reduce the need for red blood cell transfusion, even if applied shortly before cardiac surgery. The therapeutic effect on morbidity and mortality remains unclear. Nonetheless, the timely preoperative assessment of anemia and determination of iron status, eventually leading to targeted therapy, should become a standard of care and might potentially improve patient outcomes.

A comprehensive review of cerebral oximetry in cardiac surgery

BACKGROUND

Patients who undergo cardiac surgery are at increased risk of stroke, postoperative cognitive decline, and delirium. These neurocognitive complications have led to increased costs, intensive care unit stays, morbidity, and mortality. As a result, there is a significant push to mitigate any neurological complications in cardiac surgery patients. Near-infrared spectroscopy to measure regional cerebral oxygen saturations has gained consideration due to its noninvasive and user-friendly nature. Cerebral oximetry desaturations during cardiac surgery have been linked to an array of adverse clinical outcomes. However, the most effective intraoperative interventions to protect this vulnerable patient population have yet to be ascertained.

AIM OF STUDY

To provide a comprehensive summary of the intraoperative management for cerebral oximetry desaturations during cardiac surgery. The review highlights clinical outcomes from cerebral oximetry use to quantify the importance of identifying cerebral desaturations during cardiac surgery. The review then interrogates possible interventions for cerebral oximetry desaturations in an effort to determine which interventions are most efficacious and to enlighten possible areas for further research.

METHODS

A narrative review of randomized controlled trials, observational studies, and systematic reviews with metanalyses was performed through August 2021.

RESULTS

There is significant heterogeneity among patient populations for which cerebral oximetry monitoring has been studied in cardiac surgery. Further, the definition of a clinically significant cerebral desaturation and the assessment of neurocognitive outcomes varied substantially across studies. As a result, metanalysis is challenging and few conclusions can be drawn. Cerebral oximetry use during cardiac surgery has not been associated with improvements in neurocognitive outcomes, morbidity, or mortality to date. The evidence to support a particular intervention for an acute desaturation is equivocal.

CONCLUSIONS

Future research is needed to quantify a clinically significant cerebral desaturation and to determine which interventions for an acute desaturation effectively improve clinical outcomes.

Patient Blood Management: Improving Outcomes for Millions While Saving Billions. What Is Holding It Up?

Patient blood management (PBM) offers significantly improved outcomes for almost all medical and surgical patient populations, pregnant women, and individuals with micronutrient deficiencies, anemia, or bleeding. It holds enormous financial benefits for hospitals and payers, improves performance of health care providers, and supports public authorities to improve population health. Despite this extraordinary combination of benefits, PBM has hardly been noticed in the world of health care. In response, the World Health Organization (WHO) called for its 194 member states, in its recent Policy Brief, to act quickly and decidedly to adopt national PBM policies. To further support the WHO's call to action, this article addresses 3 aspects in more detail. The first is the urgency from a health economic perspective. For many years, growth in health care spending has outpaced overall economic growth, particularly in aging societies. Due to competing economic needs, the continuation of disproportionate growth in health care spending is unsustainable. Therefore, the imperative for health care leaders and policy makers is not only to curb the current spending rate relative to the gross domestic product (GDP) but also to simultaneously improve productivity, quality, safety of patient care, and the health status of populations. Second, while PBM meets these requirements on an exceptional scale, uptake remains slow. Thus, it is vital to identify and understand the impediments to broad implementation. This includes systemic challenges such as the so-called "waste domains" of failure of care delivery caused by malfunctions of health care systems, failure of care coordination, overtreatment, and low-value care. Other impediments more specific to PBM are the misperception of PBM and deeply rooted cultural patterns. Third, understanding how the 3Es-evidence, economics, and ethics-can effectively be used to motivate relevant stakeholders to take on their respective roles and responsibilities and follow the urgent call to implement PBM as a standard of care.

Anemia tolerance versus blood transfusion on long-term outcomes after colorectal cancer surgery: A retrospective propensity-score-matched analysis

Background

Perioperative anemia and transfusion are intertwined with each other, and both have adverse impacts on the survival of colorectal cancer (CRC) patients. But the treatment of anemia still relies on transfusion in several countries, which leads us to question the effects of anemia tolerance and transfusion on the long-term outcomes of CRC patients. We investigated the combined effect of preoperative anemia and postoperative anemia and of preoperative anemia and blood transfusion, which imposes a greater risk to survival, to compare the effects of anemia tolerance and transfusion on overall survival (OS) and disease-free survival (DFS) in patients undergoing CRC surgery.

Methods

A retrospective propensity-score-matched analysis included patients with CRC undergoing elective surgery between January 1, 2008, and December 31, 2014. After propensity-score matching, Kaplan–Meier survival analysis and univariable and multivariable Cox proportional hazards models were used to study the prognostic factors for survivals. In univariate and multivariate Cox regression analysis, two novel models were built.

Results

Of the 8,121 patients with CRC, 1,975 (24.3%) and 6,146 (75.7%) patients presented with and without preoperative anemia, respectively. After matching, 1,690 patients remained in each group. In the preoperative anemia and postoperative anemia model, preoperative anemia and postoperative anemia was independent risk factor for OS (HR, 1.202; 95% CI, 1.043–1.385; P=0.011) and DFS (HR, 1.210; 95% CI, 1.050–1.395; P=0.008). In the preoperative anemia and transfusion model, preoperative anemia and transfused was the most dangerous independent prognostic factor for OS (HR, 1.791; 95% CI, 1.339–2.397; P<0.001) and DFS (HR, 1.857; 95% CI, 1.389–2.483; P<0.001). In patients with preoperative anemia, the OS and DFS of patients with transfusion were worse than those of patients without transfusion (P=0.026 in OS; P=0.037 in DFS).

Conclusions

Preoperative anemia and blood transfusion imposed a greater risk to OS and DFS in patients undergoing CRC surgery, indicating that the harm associated with blood transfusion was greater than that associated with postoperative anemia. These findings should encourage clinicians to be vigilant for the timely prevention and treatment of anemia, by appropriately promoting toleration of anemia and restricting the use of blood transfusion in patients with CRC.

Non-White Race/Ethnicity and Female Sex Are Associated with Increased Allogeneic Red Blood Cell Transfusion in Cardiac Surgery Patients: 2007-2018

OBJECTIVE

To evaluate racial and/or ethnic and sex disparities in allogeneic and autologous red blood cell (RBC) transfusions in cardiac surgery.

DESIGN

A retrospective observational study.

SETTING

2007 to 2018 data from FL, MD, KY, WA, NY, and CA from the State Inpatient Databases (SID), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

PARTICIPANTS

A total of 710,296 inpatients who underwent elective or emergency coronary artery bypass grafting (CABG), cardiac valve surgery,or combination CABG and/or valve surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Patients were cohorted by race and/or ethnicity and sex, as defined by SID-HCUP. Demographic characteristics and comorbidities were compared. Rates and risk-adjusted odds ratios (aOR) were calculated for allogeneic and autologous RBC transfusion (primary outcomes). Additional secondary analyses were conducted for in-hospital mortality, 30-day readmission, 90-day readmission, hospital length of stay, and total charges to examine the effect of RBC transfusion status. Effect modification between race and sex was assessed. When controlling for patient demographics, comorbidities, and hospital characteristics, non-White patients were more likely to receive an allogeneic RBC transfusion during cardiac surgery than White patients (Black: aOR 1.17, 99% CI 1.13-1.20, p < 0.001, Hispanic: aOR 1.22, 99% CI 1.19-1.22, p < 0.001). Women were more likely to receive allogeneic RBC than men (aOR 1.69, 99% CI 1.66-1.72, p < 0.001). In interaction models, non-White women had the highest odds of allogeneic blood transfusion as compared to White men (reference category; Black women: aOR 2.04, 99% CI 1.91-2.17, p < 0.001, Hispanic women: aOR 2.03, 99% CI 1.90-2.16, p < 0.001).

CONCLUSION

These findings highlighted the differences in the rates of allogeneic RBC transfusion for non-White and female patients undergoing cardiac surgery, which is a well-established marker of poorer outcomes.

A protocol for prospective observational study to determine if non-anaemic iron deficiency worsens postoperative outcome in adult patients undergoing elective cardiac surgery: the IDOCS study

Background

Pre-operative anaemia has been associated independently with worse outcomes after cardiac surgery in adults and is often caused by absolute or functional iron deficiency. Iron deficiency is a continuum ending with anaemia, and therefore it is plausible that pre-operative early or ‘non-anaemic’ iron deficiency may also be associated with worse outcomes in patients undergoing cardiac surgery.

Methods

We have designed a prospective, observational study to determine if there is an association between non-anaemic iron deficiency and worse outcomes after cardiac surgery in adults. Patients without anaemia undergoing elective cardiac surgery will be allocated to an iron-deficient and an iron-replete group based on standard pre-operative blood tests (ferritin, transferrin saturation and C-reactive protein). The primary outcome is days alive and at home on postoperative day 30. The key secondary outcomes are days alive and at home on postoperative day 90 and readmission to acute care. Other secondary outcomes include health-related quality of life questionnaires, quality of postoperative recovery, postoperative complications, changes in haemoglobin concentration, and requirement for allogeneic blood products. The planned study sample size is 240 patients per group, which has 83% power to detect a median difference of 1.25 days in the primary outcome. The study commenced in March 2018, and recently completed recruitment, with data audit and cleaning ongoing.

Discussion

This study will be conducted using a rigorous, prospective observational design; it will provide peak bodies and clinicians with high-quality evidence concerning the associations between non-anaemic iron deficiency and patient-centred outcomes after elective cardiac surgery. Our primary and key secondary outcomes are known to have great importance to clinicians and patients alike and align with the recommendations of the StEP-COMPAC group for outcomes in prospective peri-operative research. The definition used for iron deficiency accounts for both absolute and functional iron deficiency and make use of standard pre-operative blood tests to make this determination, easing the transition of results into clinical practice. The study will be conducted in two relatively high-volume centres in a single high-income country. This limits the generalisability of study results to similar centres.

Trial registration

Australian and New Zealand Clinical Trials Registry (ACTRN12618000185268). Registered 5 February 2018.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13741-022-00239-2.

Hematinic and Iron Optimization in Peri-operative Anemia and Iron Deficiency

Purpose of Review

Preoperative anemia is independently associated with worse postoperative outcomes following cardiac and noncardiac surgery. This article explores the current understanding of perioperative anemia and iron deficiency with reference to definition, diagnosis, and treatment.

Recent Findings

Iron deficiency is the most common cause of anemia. It can arise from reduced iron intake, poor absorption, or excess iron loss. Inflammation throughout the preoperative period can drive iron sequestration, leading to a functional deficiency of iron and the development of what was referred to until recently as the “anemia of chronic disease.” Current best practice guidance supports the routine administration of preoperative intravenous iron to treat anemia despite limited evidence. This “one size fits all” approach has been called into question following results from a recent large, randomized trial (the PREVENTT trial) that assessed the use of a single dose of intravenous iron compared to placebo 10–42 days before major abdominal surgery. Although there were no improvements in patient-centered outcomes apparent during the initial hospital stay, secondary endpoints of this trial suggested there may be some late benefit after discharge from the hospital (8 weeks postoperatively). This trial raises questions on (1) the mechanisms of iron deficiency in the perioperative patient; (2) the need to reassess our opinions on generic anemia management; and (3) the need to address patient outcomes after discharge from hospital.

Summary

Despite the known associations between preoperative anemia (particularly iron deficiency anemia) and poor postoperative outcome, recent evidence suggests that administering intravenous iron relatively close to surgery does not yield a tangible short-term benefit. This is made more complex by the interplay between iron and innate immunity. Iron deficiency irrespective of hemoglobin concentration may also impact postoperative outcomes. Therefore, further research into associations between iron deficiency and postoperative outcomes, and between postoperative anemia, delayed outcomes (hospital readmission), and the efficacy of postoperative intravenous iron is required.

Preoperative anaemia and outcome after elective cardiac surgery: a Dutch national registry analysis

BACKGROUND

Previous studies have shown that preoperative anaemia in patients undergoing cardiac surgery is associated with adverse outcomes. However, most of these studies were retrospective, had a relatively small sample size, and were from a single centre. The aim of this study was to analyse the relationship between the severity of preoperative anaemia and short- and long-term mortality and morbidity in a large multicentre national cohort of patients undergoing cardiac surgery.

METHODS

A nationwide, prospective, multicentre registry (Netherlands Heart Registration) of patients undergoing elective cardiac surgery between January 2013 and January 2019 was used for this observational study. Anaemia was defined according to the WHO criteria, and the main study endpoint was 120-day mortality. The association was investigated using multivariable logistic regression analysis.

RESULTS

In total, 35 484 patients were studied, of whom 6802 (19.2%) were anaemic. Preoperative anaemia was associated with an increased risk of 120-day mortality (adjusted odds ratio [aOR] 1.7; 95% confidence interval [CI]: 1.4-1.9; P<0.001). The risk of 120-day mortality increased with anaemia severity (mild anaemia aOR 1.6; 95% CI: 1.3-1.9; P<0.001; and moderate-to-severe anaemia aOR 1.8; 95% CI: 1.4-2.4; P<0.001). Preoperative anaemia was associated with red blood cell transfusion and postoperative morbidity, the causes of which included renal failure, pneumonia, and myocardial infarction.

CONCLUSIONS

Preoperative anaemia was associated with mortality and morbidity after cardiac surgery. The risk of adverse outcomes increased with anaemia severity. Preoperative anaemia is a potential target for treatment to improve postoperative outcomes.

Cardiac Surgery in Patients With Blood Disorders

Blood disorders that can contribute to abnormal bleeding can have a detrimental effect during cardiac surgery. Patients who are known to have such pathologies should be investigated thoroughly and cautious measures would need to be taken when cardiac surgery is needed in this cohort. The majority of current literature for cardiac surgery in patients with von Willebrand Disease and haemophilia are case reports. Nevertheless, evidence shows that optimising factor levels pre, intra and postoperatively offers outcomes similar to that of patients without these disorders. Preoperative screening followed by appropriate iron therapy reduces mortality for patients with anaemia. In this group, haemoglobin levels can be improved postoperatively through iron supplementation. The management strategy of cardiac surgery for people with blood disorders requires a multidisciplinary approach that is highly individualised for each patient. It is essential to adequately adjust preoperative, perioperative and postoperative care to the patient's blood disorder in order to achieve outcomes similar to that of patients without blood disorders.

Association between perioperative allogeneic red blood cell transfusion and infection after clean-contaminated surgery: a retrospective cohort study

BACKGROUND

Allogeneic red blood cell (RBC) transfusion can induce immunosuppression, which can then increase the susceptibility to postoperative infection. However, studies in different types of surgery show conflicting results regarding this effect.

METHODS

In this retrospective cohort study conducted in a tertiary referral centre, we included adult patients undergoing clean-contaminated surgery from 2014 to 2018. Patients who received allogeneic RBC transfusion from preoperative Day 30 to postoperative Day 30 were included into the transfusion group. The control group was matched for the type of surgery in a 1:1 ratio. The primary outcome was infection within 30 days after surgery, which was defined by healthcare-associated infection, and identified mainly based on antibiotic regimens, microbiology tests, and medical notes.

RESULTS

Among the 8098 included patients, 1525 (18.8%) developed 1904 episodes of postoperative infection. Perioperative RBC transfusion was associated with an increased risk of postoperative infection after controlling for 27 confounders by multivariable regression analysis (odds ratio [OR]: 1.60; 95% confidence interval [CI]: 1.39-1.84; P<0.001) and propensity score weighing (OR: 1.64; 95% CI: 1.45-1.85; P<0.001) and matching (OR: 1.70; 95% CI: 1.43-2.01; P<0.001), and a dose-response relationship was observed. The transfusion group also showed higher risks of surgical site infection, pneumonia, bloodstream infection, multiple infections, intensive care admission, unplanned reoperation, prolonged postoperative length of hospital stay, and all-cause death.

CONCLUSIONS

Perioperative allogeneic RBC transfusion is associated with an increased risk of infection after clean-contaminated surgery in a dose-response manner. Close monitoring of infections and enhanced prophylactic strategies should be considered after transfusion.

Need for preoperative anemia management clinics in Japan: initiatives at a university hospital in the USA

Untreated preoperative anemia increases the risk of morbidity and mortality and there is increasing evidence that early intervention for preoperative anemia improves outcomes after major surgery. Accordingly, anemia management clinics have been established in various institutions in the USA. As an example, the University of Iowa Hospitals and Clinics outpatient clinic treats pre-surgical anemic patients, who undergo major surgery with anticipated blood loss of more than 500 mL, by providing effective standardized care in a timely manner. This standardized care is an integral part of patient blood management to reduce perioperative blood transfusion and improve patient outcomes. The importance of preoperative anemia management has not yet been sufficiently recognized in Japan. Timely intervention for preoperative anemia should be incorporated into routine pre-surgical patient care in Japan.