Preoperative Anemia in Cardiac Operation: Does Hemoglobin Tell the Whole Story?

Analysis of Anemia, Transfusions, and CABG Outcomes in The Society of Thoracic Surgeons National Database

BACKGROUND

This study characterized the association of preoperative anemia and intraoperative red blood cell (RBC) transfusion on outcomes of elective coronary artery bypass grafting (CABG).

METHODS

Data from 53,856 patients who underwent CABG included in The Society of Thoracic Surgeons (STS) Adult Cardiac Database in 2019 were used. The primary outcome was operative mortality. Secondary outcomes were postoperative complications. The association of anemia with outcomes was analyzed with multivariable regression models. The influence of intraoperative RBC transfusion on the effect of preoperative anemia on outcomes was studied using mediation analysis.

RESULTS

Anemia was present in 25% of patients. Anemic patients had a higher STS Predicted Risk of Operative Mortality (1.2% vs 0.7%; P < .001). Anemia was associated with operative mortality (odds ratio [OR], 1.27; 99.5% CI, 1.00-1.61; P = .047), postoperative RBC transfusion (OR, 2.28; 99.5% CI, 2.12-2.44; P < .001), dialysis (OR, 1.58; 99.5% CI, 1.19-2.11; P < .001), and prolonged intensive care unit and hospital length of stay. Intraoperative RBC transfusion largely mediated the effects of anemia on mortality (76%), intensive care unit stay (99%), and hospital stay, but it only partially mediated the association with dialysis (34.9%).

CONCLUSIONS

Preoperative anemia is common in patients who undergo CABG and is associated with increased postoperative risks of mortality, complications, and RBC transfusion. However, most of the effect of anemia on mortality is mediated through intraoperative RBC transfusion.

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.

How Important Impact of Low Level of Hematocrit Can Be on Outcome in Patients Undergoing Off Pump Coronary Artery Bypass Surgery?

Background

Cardiosurgical patients can be often anemic, and preoperative anaemia is associated with increased postoperative complications, as well as morbidity and mortality.

Objective

The present study was conducted aiming to determine the influence of lower preoperative hematocrit values on the early postoperative recovery of patients undergoing elective off-pump coronary artery bypass grafting (OPCABG).

Methods

Our retrospective study included 150 patients who underwent elective OPCABG surgery from September 2021 to December 2022 at the Clinic for Cardiovascular Surgery University of Sarajevo. Patients were divided into two groups, anemic and non-anemic, with anemia defined as hemoglobin level <130g/l males and <120g/l females. Study observed comorbidities and early postoperative data.

Results

Overall prevalence of anemia in OPCABG patients was 36,6%, more frequent among older patients. Comorbidities as chronic obstructive pulmonary disease, hypertension, ejection fraction was quite similar in both groups, but body mass index was significantly higher in the group of patients with anemia (29.9% vs 28.4%). In early recovery period, vasopressors were more used in patients with anemia (63.6% vs 42.1%) and their doses were higher. Total drainage was higher in patients with anemia (744.45±45.72 ml vs 681.58±349.06 ml). Number of transfusions was higher in the group of patients with anemia: red blood cells (0.89±1.29 vs 0.29±0.84; p<0,05), fresh frozen plasma (0.65±1.13 vs 0.41±1.15; p<0,05) and platelets (0.11±0.57 vs 0,07±0.42; p>0,05). Duration of mechanical ventilation was longer in patients with anemia compared to non-anemic patients (623-91±259.83 minutes vs 469±191.13 minutes). Atrial fibrillation occurred more often in patients with anemia (12.7 vs 7.4%). Length of stay in the intensive care unit was without significant difference.

Conclusion

Based on our findings, patients who underwent elective OPCABG with lower than normal hematocrit, needed more blood and blood products, more vasopressor drugs in higher doses, longer mechanical ventilation, all which can prolong the patient's recovery and increase the cost of treatment.

Development of a nomogram for predicting nosocomial infections among patients after cardiac valve replacement surgery

AIMS AND OBJECTIVES

To construct a predictive nomogram of the risk of nosocomial infections among patients after cardiac valve replacement surgery.

BACKGROUND

Nosocomial infections are a standout challenge that worsens the prognosis of patients after valve replacement surgery. However, studies on the nomogram of nosocomial infections in these patients have remained scarce.

DESIGN

A retrospective cohort study.

METHODS

Patients (n = 720) following valve replacement surgery from 2018 to 2019 were selected. LASSO regression and multivariate logistic regression were utilised to ascertain predictors of nosocomial infections. The predictive performance of the nomogram was appraised by calibration and discrimination. Decision and impact curves were used to assess the clinical utility. Internal validation was implemented via 1000 bootstrap samples to mitigate overfitting. TRIPOD guidelines were used in this study.

RESULTS

One hundred and fifty one patients (20.97%) experienced nosocomial infections following valve replacement surgery. Heart failure, preoperative anaemia, valve material, American Society of Anesthesiologists score ≥ IV, prolonged duration of surgery, duration of mechanical ventilation ≥ 24 h and indwelling nasogastric tube were predictors of nosocomial infections. Using these variables, we developed a predictive nomogram of the occurrence of nosocomial infections and the internal validation results demonstrated good discrimination and calibration of the nomogram. The clinical decision and impact curve revealed significant clinical utility.

CONCLUSIONS

The present study constructed a nomogram for predicting the risk of nosocomial infections in patients following cardiac valve replacement surgery. This nomogram may strengthen the effective screening of patients at high risk of nosocomial infections.

RELEVANCE TO CLINICAL PRACTICE

This risk warning tool can assist clinical staff in making decisions and providing individualised infection control measures for patients, which has a significant reference value for clinical practice.

NO PATIENT OR PUBLIC CONTRIBUTION

The data for this study were obtained from the hospital database, and the entire process of the study did not involve patient participation.

Perioperative Anemia and Transfusions and Late Mortality in Coronary Artery Bypass Patients

BACKGROUND

Perioperative anemia and transfusions are associated with adverse operative outcomes after coronary artery bypass graft surgery (CABG). Their individual association with long-term outcomes is unclear.

METHODS

Patients aged 65 years and older who had undergone CABG and were in The Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database (n = 504,596) from 2011 to 2018 were linked to Centers for Medicare and Medicaid Service data to assess long-term survival. The association of intraoperative anemia defined by intraoperative nadir hematocrit (nHct) and red blood cell (RBC) transfusions, and their interactions, on long-term mortality were assessed with Kaplan-Meier estimates and multivariable Cox regression. Restricted cubic splines were used to explore the association between nHct as a continuous variable and long-term mortality.

RESULTS

258,398 on-pump CABG STS Adult Cardiac Surgery Database patients surviving the perioperative period were linked to Centers for Medicare and Medicaid Service claims files. Per World Health Organization criteria, 41% had preoperative anemia. Mean intraoperative nHct was 24%; RBC transfusion rate was 43.7%. Univariable analysis associated both RBC transfusion and lower nHct with worse survival. Lower nHct was only marginally associated with risk-adjusted mortality: adjusted hazard ratio (AHR) 1.04 (95% CI, 1.01-1.06) and 1.07 (95% CI, 1.00-1.14) at nHct 20% and at nHct 14%, respectively. RBC transfusion was associated with significantly higher adjusted mortality irrespective of timing of transfusion: AHR intraoperative 1.21 (95% CI, 1.18-1.27); AHR postoperative 1.26 (95% CI, 1.22-1.30); AHR both 1.46 (95% CI, 1.40-1.52) and across all levels of nHct. RBC transfusion was not associated with improved survival at any level of nHct.

CONCLUSIONS

Among Medicare CABG patients, RBC transfusions were associated with increased risk-adjusted late mortality across all levels of nHct whereas intraoperative anemia was only marginally so. Tolerance of lower intraoperative nHct than currently accepted may be preferable to transfusions.

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.

Clinical presentation and in-hospital outcomes of intraoperative red blood cell transfusion in non-anemic patients undergoing elective valve replacement

Background

Intraoperative transfusion is associated with adverse clinical outcomes in cardiac surgery. However, few studies have shown the impact of intraoperative red blood cell (RBC) transfusion on non-anemic patients undergoing cardiac surgery. We assessed the in-hospital clinical outcomes of non-anemic patients undergoing isolated valve replacements and investigated the predictors associated with intraoperative RBC transfusion.

Methods

We enrolled 345 non-anemic patients undergoing isolated valve replacements in our department from January 2015 to December 2019. The patients were stratified by the receipt of intraoperative RBC transfusion. Baseline characteristics were compared between groups and multiple logistic regression was used to identify the predictors for intraoperative RBC transfusion. The association between intraoperative RBC transfusion and in-hospital outcomes was also evaluated.

Results

Intraoperative RBC transfusion developed in 84 of the 345 enrolled patients (24.3%). Three independent predictors for intraoperative RBC transfusion of non-anemic patients undergoing isolated valve replacements were identified by multivariate logistic analysis, including female, iron deficiency and hemoglobin level. When the two groups were compared, a significant tendency of higher in-hospital mortality (6.0% vs. 1.1%, P = 0.033) and higher incidence of postoperative hypoxemia (9.5% vs. 2.7%, P = 0.007) were observed in the intraoperative RBC transfusion group. After adjustment, the presence of intraoperative RBC transfusion was associated with an increase in postoperative hypoxemia (OR = 3.36, 95% CI: 1.16–9.71, P = 0.026).

Conclusion

Intraoperative RBC transfusion was associated with poorer clinical outcomes in non-anemic adults undergoing isolated valve replacements, which significantly increased the risk of postoperative hypoxemia. The independent predictors of intraoperative RBC transfusion, such as iron deficiency and female, were identified, which may be helpful for risk assessment and perioperative management.

Effects of recombinant erythropoietin on hemoglobin levels and blood transfusion needs in patients with preoperative anemia undergoing cardiac surgery

INTRODUCTION

Preoperative anemia is an important and relatively common problem in patients undergoing cardiac surgery, and its treatment is crucial in improving postoperative outcomes. The use of recombinant erythropoietin is one of the suggested methods in this field. Therefore, in the present study, we sought to evaluate the effects of recombinant erythropoietin on hemoglobin (Hb) levels and blood transfusion needs in cardiac surgery in patients with preoperative anemia.

METHODS

This randomized nonblind clinical trial was performed on patients with mild-to-moderate anemia (Hb &lt;12 g/dL in men and Hb &lt;11 g/dL in women) undergoing cardiac surgery at a referral heart hospital (Tehran, Iran). The patients were randomly divided into two groups of 33 patients. In the intervention group, recombinant erythropoietin was administered at a dose of 500 IU/kg one to three days before surgery. Intra- and postoperative Hb levels and the need for blood transfusion were recorded during surgery and for 3 days afterward.

RESULTS

The use of packed red blood cells in the operating room was similar in the intervention and control groups (P = 0.156), but it was significantly lower in the intensive care unit in the intervention group (P = 0.030). The mean Hb, which was initially identical in the two groups (P &gt; 0.05), showed a significantly lower decrease in the intervention group (P = 0.001). No significant differences were observed concerning other variables.

CONCLUSIONS

The use of recombinant erythropoietin (500 IU/kg/day) one to three days before cardiac surgery in our anemic patients blunted a reduction in Hb levels and decreased blood transfusion needs.

A novel model forecasting perioperative red blood cell transfusion

We aimed to establish a predictive model assessing perioperative blood transfusion risk using a nomogram. Clinical data for 97,443 surgery patients were abstracted from the DATADRYAD website; approximately 75% of these patients were enrolled in the derivation cohort, while approximately 25% were enrolled in the validation cohort. Multivariate logical regression was used to identify predictive factors for transfusion. Receiver operating characteristic (ROC) curves, calibration plots, and decision curves were used to assess the model performance. In total, 5888 patients received > 1 unit of red blood cells; the total transfusion rate was 6.04%. Eight variables including age, race, American Society of Anesthesiologists' Physical Status Classification (ASA-PS), grade of kidney disease, type of anaesthesia, priority of surgery, surgery risk, and an 18-level variable were included. The nomogram achieved good concordance indices of 0.870 and 0.865 in the derivation and validation cohorts, respectively. The Youden index identified an optimal cut-off predicted probability of 0.163 with a sensitivity of 0.821 and a specificity of 0.744. Decision curve (DCA) showed patients had a standardized net benefit in the range of a 5–60% likelihood of transfusion risk. In conclusion, a nomogram model was established to be used for risk stratification of patients undergoing surgery at risk for blood transfusion. The URLs of web calculators for our model are as follows: http://www.empowerstats.net/pmodel/?m=11633_transfusionpreiction.

Preoperative Anemia is Associated with Increased Intraoperative Mortality in Patients Undergoing Cardiac Surgery

Objectives

We sought to investigate the incidence of preoperative anemia in cardiac surgery and its association with outcomes.

Methods

A retrospective review of clinical, laboratory, and transfusion data for all patients who underwent cardiac surgery at Sultan Qaboos University Hospital between 2008 and 2014 was performed. Patients were divided into two groups, anemic and non-anemic, with anemia defined as hemoglobin levels < 13 g/dL (males) and < 12 g/dL (females). Clinical variables were compared using chi-square and independent t-test. Factors influencing preoperative mortality were analyzed using multivariate binary logistics regression.

Results

A total of 599 patients (69.9% males and 30.1% females) were included in the study; 69.3% underwent coronary artery bypass surgery. Preoperative anemia was found in 76.1% of females and 26.7% of male patients. Rates of intraoperative red blood cell transfusions were higher among anemic patients (75.9% vs. 52.3%, p < 0.001). Anemic patients had a worse risk profile with higher incidence of diabetes mellitus (53.8% vs. 38.9%, p < 0.001), congestive heart failure (51.4% vs. 28.3%, p < 0.001), arrhythmia (16.5% vs. 8.6%, p = 0.004), and cerebrovascular disease (10.0% vs. 4.9%, p = 0.015). In addition, they had a higher risk of overall mortality (6.4% vs. 2.6%, p = 0.023). Preoperative anemia remained a risk factor for intraoperative mortality after logistic regression (odds ratio = 4.08, 95% confidence interval: 1.43–11.66; p = 0.009).

Conclusions

Preoperative anemia in cardiac surgery is independently associated with increased intraoperative mortality and early readmission rates post-surgery.

Preoperative anemia and transfusion in cardiac surgery: a single-centre retrospective study

Background

Preoperative anemia and transfusion are associated with worse outcomes. This study aims to identify the prevalence of preoperative anemia, transfusion rates on surgery day, and predictors of transfusion in elective cardiac surgery patients at our centre. We also aim to evaluate our preoperative intervention program, and examine the intervention window for anemia before surgery.

Methods

This study included 797 adult patients who underwent elective cardiac surgery at a tertiary hospital. Multivariable logistic regression analysis was used to identify predictors of transfusion on surgery day.

Results

Preoperative anemia was present in 15% of patients. Anemic patients had a significantly higher transfusion rate at 53% compared to 10% in non-anemic patients. Hemoglobin concentration, estimated glomerular filtration rate (eGFR), body surface area (BSA), and total cardiopulmonary bypass time were predictive of transfusion on surgery day. Patients had a median of 7 days between initial visit and surgery day, however, referral to the blood conservation clinic was only done for 8% of anemic patients and treatment was initiated in 3% of anemic patients. Among the 3 anemic patients who received treatment, 2 did not require blood transfusion on surgery day.

Conclusions

Preoperative anemia is present in 15% of patients at our centre and these patients have 53% transfusion rates on surgery day. Hemoglobin concentration, eGFR, BSA, and total cardiopulmonary bypass time were predictors of transfusion on surgery day. Patients had a median of 7 days between initial visit and surgery day. Referral and anemia treatment were infrequently initiated in preoperative anemic patient.

Iron supplementation for patients undergoing cardiac surgery: a protocol for a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Iron administration has been evaluated in several randomized controlled trials for the potential of increasing baseline hemoglobin values and decreasing the incidence of red blood cell transfusion during cardiac surgery. We describe the protocol for a study aiming to evaluate the efficacy and safety of perioperative iron administration in patients undergoing cardiac surgery.

METHODS

We will search MEDLINE, Embase, the Cochrane Central Register of Controlled Trials and the Web of Science, from inception to Nov. 19, 2020, for randomized controlled trials in any language evaluating the perioperative administration of iron in adult patients undergoing cardiac surgery; we will also include the first 50 results from Google Scholar. The primary outcome will be the incidence of red blood cell transfusion from the study intervention time until 8 weeks postoperatively. The secondary outcomes will be the number of red blood cell units transfused; change in ferritin level, reticulocyte count and hemoglobin concentration after iron administration; and adverse events. We will assess the risk of bias with the Cochrane Collaboration Risk of Bias Tool, and will analyze the primary and secondary outcomes using a random-effects model.

INTERPRETATION

This study will summarize the current evidence about perioperative iron administration in patients undergoing cardiac surgery, help determine whether this intervention should be included in enhanced-recovery protocols, and shape future research if needed. The final manuscript will be submitted to a peer-reviewed journal.

TRIAL REGISTRATION

PROSPERO no. CRD42020161927.

The Effect of Preoperative Hematocrit Levels on Early Outcomes After Coronary Artery Bypass Graft

Introduction

Coronary artery bypass graft (CABG) is the most potent of surgical procedures; in this procedure, the narrowing of the coronary artery due to atherosclerotic plaque is bypassed by forming an alternate route for blood flow to the heart. There are various risk factors associated with the procedure. The aim of this study was to observe if postoperative outcomes are affected by preoperative hematocrit (hct) levels in patients.

Methods 

This longitudinal study was conducted from April 2019 to December 2019. Eighty-two (82) participants who were to undergo CABG surgery were divided into two groups based on their preoperative hct levels. Group 1 had 42 participants with lower levels of hct (less than 35.5% for women and 38.3% for men), whereas group 2 consisted of 40 participants with normal hct levels (greater than 35.5% for women and 38.3% for men).

Results

The results showed that participants undergoing CABG with lower than normal hct levels had increased blood loss through drainage as compared to participants who had normal hct levels (680.1 ± 301 mL vs. 500.7 ± 412 mL; p-value: 0.02). Group 1 participants also had an increased need for blood and blood product transfusion as compared to group 2 (3.2 ± 1.8 units vs. 1.8 ± 0.9 units; p-value: <0.0001). Furthermore, the participants in group 1 had longer stays in the ICU relative to the other group (5.2 ± 3.1 days vs. 3.4 ± 2.5 days; p-value: 0.003).

Conclusion

Based on our findings, patients who undergo CABG surgery with lower than normal hct levels are at increased risk of certain complications, including excessive blood loss, need for transfusion, and increased duration of ICU stay. Therefore, preoperative hct levels should be routinely checked in patients undergoing CABG to prevent these complications.

The Effect of Preoperative Hematocrit Level on Early Outcomes After Coronary Artery Bypass Surgery

INTRODUCTION

Low hematocrit level is a hematological problem that is frequently encountered in the preoperative evaluation of patients undergoing coronary artery bypass grafting (CABG) surgery. The aim of this study was to investigate the effect of preoperative hematocrit level on the first 30-day outcomes in patients undergoing CABG surgery.

METHODS

Ninety-four patients undergoing isolated CABG were included in the study. The patients were divided into two groups as patients with preoperative low hematocrit levels (<36%) in Group 1 and patients with preoperative normal hematocrit levels (≥36%) in Group 2.

RESULTS

Forty-six patients in Group 1 (mean age: 63.6 ± 7.9 years) and 48 patients in Group 2 (mean age: 56.5 ± 8.8 years) were enrolled. European System for Cardiac Operative Risk Evaluation (EuroSCORE) scoring was statistically significantly higher in Group 1 (p = 0.011). In the postoperative period, the amount of drainage, transfusion of blood, and blood products were significantly higher in Group 1 (p < 0.001). The mortality rate of Group 1 was statistically higher in the first 30 days postoperatively (p = 0.020).

CONCLUSION

Low preoperative hematocrit levels are associated with increased mortality after CABG surgery. We suggest that patients' preoperative hematocrit levels must be added to the risk scoring systems as an assessment parameter.

Association of Preoperative Anemia With 30-Day Morbidity and Mortality Among Patients With Thyroid Cancer Who Undergo Thyroidectomy

Importance

Despite the ease of preoperative anemia diagnosis and the availability of treatment options, the morbidity and mortality associated with this condition remain unacceptably high, and the literature describing the association of preoperative anemia with postoperative outcomes following thyroid surgery in patients with thyroid cancer remain sparse. Reporting outcomes in this patient population may help to facilitate preoperative optimization.

Objective

To assess whether an association exists between preoperative anemia and outcomes following thyroid surgery in patients with thyroid cancer.

Design, Setting, and Participants

This retrospective, cross-sectional, cohort study used the American College of Surgeons National Surgical Quality Improvement Program database to identify 32 166 patients between 2007 and 2016 with Current Procedural Terminology codes for thyroid surgery and with the International Classification of Diseases, Ninth Revision code of malignant thyroid cancer.

Exposures

Preoperative anemia as defined using the World Health Organization criteria of hematocrit less than 36% in nonpregnant females and less than 39% in males.

Main Outcomes and Measures

Multivariable logistic regression analysis was conducted to assess the association of preoperative anemia with the following 30-day postoperative outcomes: pulmonary, infectious, and cardiac complications, overall and serious morbidity (surgical site infection and medical complications), prolonged hospital length of stay (≥75th percentile for the cohort), and mortality.

Results

Among the 24 912 patients with thyroid cancer who underwent thyroidectomy included in the final analysis, the median (interquartile range) age was 51 (40-62) years and the majority were women (18 705 [75.1%]). The prevalence of preoperative anemia was 12.5% (n = 3108). Within the overall study population, hypertension (9242 patients [37.1%]) followed by active smoking (2992 patients [12.0%]) were the most prevalent comorbidities. The unadjusted odds of anemia vs no anemia were significantly higher for every 10-year increase in age (odds ratio [OR], 1.10; 95% CI, 1.08-1.13) and for black vs white patients (OR, 2.82; 95% CI, 2.51-3.17). The adjusted odds of postoperative overall morbidity (OR, 1.68; 95% CI, 1.29-2.17), mortality (OR, 3.36; 95% CI, 1.37-8.28), and pulmonary (OR, 2.36; 95% CI, 1.65-3.34) and infectious (OR, 1.62; 95% CI, 1.12-2.29) complications were higher in patients with preoperative anemia than in those without preoperative anemia.

Conclusions and Relevance

The findings from this study suggest that preoperative anemia may not only be associated with racial differences and a higher comorbidity burden but may also increase the likelihood of postoperative morbidity and mortality. These results may provide a basis for further risk reduction strategies and preoperative optimization.

Society of Cardiovascular Anesthesiologists Clinical Practice Improvement Advisory for Management of Perioperative Bleeding and Hemostasis in Cardiac Surgery Patients

Bleeding after cardiac surgery is a common and serious complication leading to transfusion of multiple blood products and resulting in increased morbidity and mortality. Despite the publication of numerous guidelines and consensus statements for patient blood management in cardiac surgery, research has revealed that adherence to these guidelines is poor, and as a result, a significant variability in patient transfusion practices among practitioners still remains. In addition, although utilization of point-of-care (POC) coagulation monitors and the use of novel therapeutic strategies for perioperative hemostasis, such as the use of coagulation factor concentrates, have increased significantly over the last decade, they are still not widely available in every institution. Therefore, despite continuous efforts, blood transfusion in cardiac surgery has only modestly declined over the last decade, remaining at ≥50% in high-risk patients. Given these limitations, and in response to new regulatory and legislature requirements, the Society of Cardiovascular Anesthesiologists (SCA) has formed the Blood Conservation in Cardiac Surgery Working Group to organize, summarize, and disseminate the available best-practice knowledge in patient blood management in cardiac surgery. The current publication includes the summary statements and algorithms designed by the working group, after collection and review of the existing guidelines, consensus statements, and recommendations for patient blood management practices in cardiac surgery patients. The overall goal is creating a dynamic resource of easily accessible educational material that will help to increase and improve compliance with the existing evidence-based best practices of patient blood management by cardiac surgery care teams.

Consensus Report on Patient Blood Management in Cardiac Surgery by Turkish Society of Cardiovascular Surgery (TSCVS), Turkish Society of Cardiology (TSC), and Society of Cardio-Vascular-Thoracic Anaesthesia and Intensive Care (SCTAIC)

Anemia, transfusion and bleeding independently increase the risk of complications and mortality in cardiac surgery. The main goals of patient blood management are to treat anemia, prevent bleeding, and optimize the use of blood products during the perioperative period. The benefit of this program has been confirmed in many studies and its utilization is strongly recommended by professional organizations. This consensus report has been prepared by the authors who are the task members appointed by the Turkish Society of Cardiovascular Surgery, Turkish Society of Cardiology (TSC), and Society of Cardio-Vascular-Thoracic Anaesthesia and Intensive Care to raise the awareness of patient blood management. This report aims to summarize recommendations for all perioperative blood- conserving strategies in cardiac surgery.

Association of preoperative anaemia with cardiopulmonary exercise capacity and postoperative outcomes in noncardiac surgery: a substudy of the Measurement of Exercise Tolerance before Surgery (METS) Study

BACKGROUND

Preoperative anaemia is associated with elevated risks of postoperative complications. This association may be explained by confounding related to poor cardiopulmonary fitness. We conducted a pre-specified substudy of the Measurement of Exercise Tolerance before Surgery (METS) study to examine the associations of preoperative haemoglobin concentration with preoperative cardiopulmonary exercise testing performance (peak oxygen consumption, anaerobic threshold) and postoperative complications.

METHODS

The substudy included a nested cross-sectional analysis and nested cohort analysis. In the cross-sectional study (1279 participants), multivariate linear regression modelling was used to determine the adjusted association of haemoglobin concentration with peak oxygen consumption and anaerobic threshold. In the nested cohort study (1256 participants), multivariable logistic regression modelling was used to determine the adjusted association of haemoglobin concentration, peak oxygen consumption, and anaerobic threshold with the primary endpoint (composite outcome of death, cardiovascular complications, acute kidney injury, or surgical site infection) and secondary endpoint (moderate or severe complications).

RESULTS

Haemoglobin concentration explained 3.8% of the variation in peak oxygen consumption and anaerobic threshold (P<0.001). Although not associated with the primary endpoint, haemoglobin concentration was associated with moderate or severe complications after adjustment for peak oxygen consumption (odds ratio=0.86 per 10 g L^-1 increase; 95% confidence interval, 0.77-0.96) or anaerobic threshold (odds ratio=0.86; 95% confidence interval, 0.77-0.97). Lower peak oxygen consumption was associated with moderate or severe complications without effect modification by haemoglobin concentration (P=0.12).

CONCLUSION

Haemoglobin concentration explains a small proportion of variation in exercise capacity. Both anaemia and poor functional capacity are associated with postoperative complications and may therefore be modifiable targets for preoperative optimisation.

Prognostic Value of Preoperative Red Cell Distribution Width: Fine-Tuning by Mean Corpuscular Volume

BACKGROUND

Abnormal red cell distribution width (RDW), reflecting heterogeneity of red blood cell (RBC) size, is associated with cardiovascular disease outcomes. However, whether RBC size itself, expressed as mean corpuscular volume (MCV), provides additional prognostic value is unclear. We therefore investigated the relationship between outcomes after cardiac surgery and both RDW and MCV simultaneously.

METHODS

From January 2010 to January 2014, 16,097 patients underwent cardiac surgery at Cleveland Clinic and had complete blood count findings available for analysis. Outcomes included RBC transfusion, postoperative complications, and intensive care unit (ICU) and postoperative hospital lengths of stay. Risk-adjusted associations of RDW and MCV with outcomes and their relative importance in predicting outcome were identified by random forest machine learning.

RESULTS

High RDW was associated with more RBC transfusions. Except for postoperative atrial fibrillation, risks of complications and ICU and postoperative lengths of stay were at their minimum when RDW was normal, 13% to 14%. The relationship of MCV to complications was U-shaped: high (macrocytosis) and low (microcytosis) values were associated with higher risk. RDW was an important risk factor for most postoperative outcomes and lengths of stay; MCV was less so, but provided prognostic value in addition to RDW alone, particularly when there was macrocytosis.

CONCLUSIONS

Abnormal RDW and MCV are associated with higher risk of transfusion and postoperative outcomes after cardiac surgery. RDW is one of the most important variables in predicting outcomes, but MCV provides additional prognostic value. Both should be taken into consideration when estimating the perioperative risk of patients undergoing cardiac surgery.

Patient Blood Management: Recommendations From the 2018 Frankfurt Consensus Conference

IMPORTANCE

Blood transfusion is one of the most frequently used therapies worldwide and is associated with benefits, risks, and costs.

OBJECTIVE

To develop a set of evidence-based recommendations for patient blood management (PBM) and for research.

EVIDENCE REVIEW

The scientific committee developed 17 Population/Intervention/Comparison/Outcome (PICO) questions for red blood cell (RBC) transfusion in adult patients in 3 areas: preoperative anemia (3 questions), RBC transfusion thresholds (11 questions), and implementation of PBM programs (3 questions). These questions guided the literature search in 4 biomedical databases (MEDLINE, EMBASE, Cochrane Library, Transfusion Evidence Library), searched from inception to January 2018. Meta-analyses were conducted with the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) methodology and the Evidence-to-Decision framework by 3 panels including clinical and scientific experts, nurses, patient representatives, and methodologists, to develop clinical recommendations during a consensus conference in Frankfurt/Main, Germany, in April 2018.

FINDINGS

From 17 607 literature citations associated with the 17 PICO questions, 145 studies, including 63 randomized clinical trials with 23 143 patients and 82 observational studies with more than 4 million patients, were analyzed. For preoperative anemia, 4 clinical and 3 research recommendations were developed, including the strong recommendation to detect and manage anemia sufficiently early before major elective surgery. For RBC transfusion thresholds, 4 clinical and 6 research recommendations were developed, including 2 strong clinical recommendations for critically ill but clinically stable intensive care patients with or without septic shock (recommended threshold for RBC transfusion, hemoglobin concentration <7 g/dL) as well as for patients undergoing cardiac surgery (recommended threshold for RBC transfusion, hemoglobin concentration <7.5 g/dL). For implementation of PBM programs, 2 clinical and 3 research recommendations were developed, including recommendations to implement comprehensive PBM programs and to use electronic decision support systems (both conditional recommendations) to improve appropriate RBC utilization.

CONCLUSIONS AND RELEVANCE

The 2018 PBM International Consensus Conference defined the current status of the PBM evidence base for practice and research purposes and established 10 clinical recommendations and 12 research recommendations for preoperative anemia, RBC transfusion thresholds for adults, and implementation of PBM programs. The relative paucity of strong evidence to answer many of the PICO questions supports the need for additional research and an international consensus for accepted definitions and hemoglobin thresholds, as well as clinically meaningful end points for multicenter trials.

Role of anesthesiologists in managing perioperative anemia

PURPOSE OF REVIEW

Anemia can contribute negatively to a patient's morbidity and mortality. Which treatment options do exist and what role do anesthesiologists play in management of perioperative anemia treatment? This review gives an overview about recent findings.

RECENT FINDINGS

Patient Blood Management and standards for the management and treatment of anemia have been established worldwide. Various logistic settings and approaches are possible. With a special focus on cardiovascular anesthesia, intravenous iron is a therapeutic option in the preoperative setting. Autologous blood salvage is a standard procedure during surgery. Restrictive transfusion triggers in adult cardiac surgery have been shown to be beneficial in the majority of studies. Elderly patients and defined comorbidities might require higher transfusion triggers. Both, intravenous and oral iron increase hemoglobin values when given prior to surgery. Oral iron is effective when given several weeks prior to elective surgery. Erythropoietin is a treatment decision individualized to each patient.

SUMMARY

Within the previous 18 months, important publications have demonstrated the established role of anesthesiologists in managing perioperative anemia. A substantial pillar for anemia treatment is the implementation of Patient Blood Management worldwide.

Optimizing Preoperative Anemia to Improve Patient Outcomes

Anemia is a decrease in red blood cell mass, which hinders oxygen delivery to tissues. Preoperative anemia has been shown to be associated with mortality and morbidity following major surgery. The preoperative care clinic is an ideal place to start screening for anemia and discussing potential interventions in order to optimize patients for surgery. This article (1) reviews the relevant literature and highlights consequences of preoperative anemia in the surgical setting, and (2) suggests strategies for screening and optimizing anemia in the preoperative setting.

Tracheal release maneuvers

Tracheal resection and reconstruction has been slow to develop in the field of thoracic surgery. The ability to perform a low tension, well-vascularized anastomosis with good outcomes has improved with understanding of tracheal blood supply and the ability to perform tracheal release maneuvers. Laryngeal and suprahyoid release maneuvers can be helpful for cervical tracheal resections, while hilar and pericardial release maneuvers can be beneficial in thoracic tracheal resections. Simple maneuvers such as neck flexion and dissection of the avascular pretracheal plane can also be used to improve anastomotic tension. In this paper, we will review the indications, technical considerations and results of performing cervical and intrathoracic tracheal release maneuvers during tracheal resection and reconstruction.