Miniaturized Cardiopulmonary Bypass and Acute Kidney Injury in Coronary Artery Bypass Graft Surgery

Cardiopulmonary bypass associated acute kidney injury: better understanding and better prevention

Cardiopulmonary bypass (CPB) is a common technique in cardiac surgery but is associated with acute kidney injury (AKI), which carries considerable morbidity and mortality. In this review, we explore the range and definition of CPB-associated AKI and discuss the possible impact of different disease recognition methods on research outcomes. Furthermore, we introduce the specialized equipment and procedural intricacies associated with CPB surgeries. Based on recent research, we discuss the potential pathogenesis of AKI that may result from CPB, including compromised perfusion and oxygenation, inflammatory activation, oxidative stress, coagulopathy, hemolysis, and endothelial damage. Finally, we explore current interventions aimed at preventing and attenuating renal impairment related to CPB, and presenting these measures from three perspectives: (1) avoiding CPB to eliminate the fundamental impact on renal function; (2) optimizing CPB by adjusting equipment parameters, optimizing surgical procedures, or using improved materials to mitigate kidney damage; (3) employing pharmacological or interventional measures targeting pathogenic factors.

Adverse renal effects associated with cardiopulmonary bypass

Cardiac surgery on cardiopulmonary bypass (CPB) is associated with postoperative renal dysfunction, one of the most common complications of this surgical cohort. Acute kidney injury (AKI) is associated with increased short-term morbidity and mortality and has been the focus of much research. There is increasing recognition of the role of AKI as the key pathophysiological state leading to the disease entities acute and chronic kidney disease (AKD and CKD). In this narrative review, we will consider the epidemiology of renal dysfunction after cardiac surgery on CPB and the clinical manifestations across the spectrum of disease. We will discuss the transition between different states of injury and dysfunction, and, importantly, the relevance to clinicians. The specific facets of kidney injury on extracorporeal circulation will be described and the current evidence evaluated for the use of perfusion-based techniques to reduce the incidence and mitigate the complications of renal dysfunction after cardiac surgery.

The Treatment of Coronary Artery Disease in Patients with Chronic Kidney Disease: Gaps, Challenges, and Solutions

Background

Chronic kidney disease (CKD) is associated with a high burden of coronary artery disease (CAD), which remains the leading cause of death in CKD patients. Despite the high cardiovascular risk, ACS patients with renal dysfunction are less commonly treated with guideline-based medical therapy and are less frequently referred for coronary revascularization.

Summary

The management of CAD is more challenging in patients with CKD than in the general population due to concerns regarding side effects and renal toxicity, as well as uncertainty regarding clinical benefit of guideline-based medical therapy and interventions. Patients with advanced CKD and especially those receiving dialysis have not traditionally been represented in randomized trials evaluating either medical or revascularization therapies. Thus, only scant data from small prospective studies or retrospective analyses are available. Recently published studies suggest that there are significant opportunities to substantially improve both cardiovascular and renal outcomes of patients with CAD and CKD, including new medications and interventions. Thus, the objective of this review is to summarize the current evidence regarding the management of CAD in CKD patients, in particular with respect to improvement of both cardiovascular and renal outcomes.

Key Messages

Adequate medical therapy and coronary interventions using evidence-based strategies can improve both cardiac and renal outcomes in patients with CAD and CKD.

Perioperative Management of the Patient at High-Risk for Cardiac Surgery-Associated Acute Kidney Injury

Acute kidney injury (AKI) is one of the most common major complications of cardiac surgery, and is associated with increased morbidity and mortality. Cardiac surgery-associated AKI has a complex, multifactorial etiology, including numerous factors such as primary cardiac dysfunction, hemodynamic derangements of cardiac surgery and cardiopulmonary bypass, and the possibility of a large volume of blood transfusion. There are no truly effective pharmacologic therapies for the management of AKI, and, therefore, anesthesiologists, intensivists, and cardiac surgeons must remain vigilant and attempt to minimize the risk of developing renal dysfunction. This narrative review describes the current state of the scientific literature concerning the specific aspects of cardiac surgery-associated AKI, and presents it in a chronological fashion to aid the perioperative clinician in their approach to this high-risk patient group. The evidence was considered for risk prediction models, preoperative optimization, and the intraoperative and postoperative management of cardiac surgery patients to improve renal outcomes.

Predictive value of neutrophil to lymphocyte ratio on acute kidney injury after on-pump coronary artery bypass: a retrospective, single-center study

Objective

To investigate the predictive value of preoperative neutrophil to lymphocyte ratio (NLR) on acute kidney injury (AKI) after on-pump coronary artery bypass (ONCAB).

Methods

Patients who underwent elective ONCAB for coronary heart disease were included. NLR was calculated according to the results of preoperative routine blood test, patients were divided into non-AKI and AKI groups, and the differences in clinical baseline data between the two groups were compared.

Results

A total of 154 patients were included in this study, including 57 (37%) with postoperative AKI and 97 (63%) without AKI. Compared with the patients in non-AKI group, those in AKI group had higher NLR (2.63 (1.83, 3.505) vs. 2.06 (1.7, 2.56), p = 0.002), higher serum creatinine (78 (67, 98.5) vs. 70.9 ± 16.8 umol/L, p < 0.001), longer cardiopulmonary bypass time, and longer aortic cross clamp time. After dividing patient into tertiles based on NLR, those with higher NLR had higher risk of postoperative AKI than those with lower NLR (30% vs. 25% vs. 55.8%, p for trend = 0.003). Patients in Tertile2 and Tertile3 had higher NLR compared to those in Tertile1 (p < 0.05); multivariate logistic regression analysis showed patients with elevated preoperative NLR and blood creatinine had higher risk of postoperative AKI. ROC curve showed that patients’ preoperative NLR combined with blood creatinine had better predictive value for postoperative AKI.

Conclusion

Elevated preoperative NLR is associated with AKI after ONCAB, and had prognostic utility independent of other recognized risk factors.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11748-022-01772-z.

Cardiac Surgery Associated AKI Prevention Strategies and Medical Treatment for CSA-AKI

Acute kidney injury (AKI) is common after cardiac surgery. To date, there are no specific pharmacological therapies. In this review, we summarise the existing evidence for prevention and management of cardiac surgery-associated AKI and outline areas for future research. Preoperatively, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers should be withheld and nephrotoxins should be avoided to reduce the risk. Intraoperative strategies include goal-directed therapy with individualised blood pressure management and administration of balanced fluids, the use of circuits with biocompatible coatings, application of minimally invasive extracorporeal circulation, and lung protective ventilation. Postoperative management should be in accordance with current KDIGO AKI recommendations.

Use of matching methods in observational studies with critical patients and renal outcomes. Scoping review

Introduction: The use of matching techniques in observational studies has been increasing and is not always used appropriately. Clinical experiments are not always feasible in critical patients with renal outcomes, and observational studies are an important alternative. Objective: Through a scoping review, determine the available evidence on the use of matching methods in studies involving critically ill patients and assessing renal outcomes. Methods: Medline, Embase, and Cochrane databases were used to identify articles published between 1992 and 2020 up to week 10, which studied different exposures in the critically ill patient with renal outcomes and used propensity matching methods. Results: Most publications are cohort studies 94 (94. 9 %), five studies (5. 1 %) were cross-sectional. The main pharmacological intervention was the use of antibiotics in seven studies (7. 1%) and the main risk factor studied was renal injury prior to ICU admission in 10 studies (10. 1%). The balance between the baseline characteristics assessed by standardized means, in only 28 studies (28. 2%). Most studies 95 (96 %) used logistic regression to calculate the propensity index. Conclusion: Major inconsistencies were observed in the use of methods and in the reporting of findings. A summary is made of the aspects to be considered in the use of the methods and reporting of the findings with the matching by propensity index.

The impact of minimal invasive extracorporeal circulation on postoperative kidney function

INTRODUCTION

Acute kidney injury following cardiac surgery is a frequent complication associated with increased mortality and morbidity. Minimal invasive extracorporeal circulation is suggested to preserve postoperative renal function. The aim of this study was to assess the impact of minimal invasive versus conventional extracorporeal circulation on early postoperative kidney function.

METHODS

Randomized controlled trail including 60 patients undergoing elective stand-alone coronary artery bypass graft surgery and allocated in a 1:1 ratio to either minimal invasive (n = 30) or conventional extracorporeal circulation (n = 30). Postoperative kidney injury was assessed by elevation of plasma neutrophil gelatinase-associated lipocalin (NGAL), a sensitive tubular injury biomarker. In addition, we assessed changes in estimated glomerular filtration rate (eGFR), and the incidence of acute kidney injury according to the Acute Kidney Injury Network (AKIN) classification.

RESULTS

We observed no differences between groups regarding increase of plasma NGAL (p = 0.31) or decline of eGFR (p = 0.82). In both groups, 6/30 patients developed acute kidney injury according to the AKIN classification, all regaining preoperative renal function within 30 days.

CONCLUSION

Our findings challenge the superiority of minimal invasive compared to conventional extracorporeal circulation in terms of preservation of renal function following low-risk coronary surgery.

Role of Renal Hypoxia in the Progression From Acute Kidney Injury to Chronic Kidney Disease

Over the past 20 years, there has been an increased appreciation of the long-term sequelae of acute kidney injury (AKI) and the potential development of chronic kidney disease (CKD). Several pathophysiologic features have been proposed to mediate AKI to CKD progression including maladaptive alterations in tubular, interstitial, inflammatory, and vascular cells. These alterations likely interact to culminate in the progression to CKD. In this article we focus primarily on evidence of vascular rarefaction secondary to AKI, and the potential mechanisms by which rarefaction occurs in relation to other alterations in tubular and interstitial compartments. We further focus on the potential that rarefaction contributes to renal hypoxia. Consideration of the role of hypoxia in AKI to CKD transition focuses on experimental evidence of persistent renal hypoxia after AKI and experimental maneuvers to evaluate the influence of hypoxia, per se, in progressive disease. Finally, consideration of methods to evaluate hypoxia in patients is provided with the suggestion that noninvasive measurement of renal hypoxia may provide insight into progression in post-AKI patients.

Acute Kidney Injury Associated with Cardiac Surgery: a Comprehensive Literature Review

Objective

To comprehensively understand cardiac surgeryassociated acute kidney injury (CSA-AKI) and methods of prevention of such complication in cardiac surgery patients.

Methods

A comprehensive literature search was performed using the electronic database to identify articles describing acute kidney injury (AKI) in patients that undergone cardiac surgery. There was neither time limit nor language limit on the search. The results were narratively summarized.

Results

All the relevant articles have been extracted; results have been summarized in each related section. CSA-AKI is a serious postoperative complication and it can contribute to a significant increase in perioperative morbidity and mortality rates. Optimization of factors that can reduce CSA-AKI, therefore, contributes to a better postoperative outcome.

Conclusion

Several factors can significantly increase the rate of AKI; identification and minimization of such factors can lead to lower rates of CSA-AKI and lower perioperative morbidity and mortality rates.

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.

Is there really a benefit of using minimized cardiopulmonary bypass in CABG? A retrospective propensity score-matched study with 5000 cases

The concept of minimized cardiopulmonary bypass targets at reduction of adverse effects triggered by extracorporeal circulation. In this study, benefits of minimized bypass in CABG were evaluated under particular consideration of patient body mass index and surgeon impact. From 2004 to 2014, 5164 patients underwent coronary bypass surgery (CABG). Conventional cardiopulmonary bypass (CCPB) was used in 2376 patients, minimized cardiopulmonary bypass (MCPB) in 2788 cases. Multivariate regression models were used in the entire cohort and in a propensity score-matched subgroup after expert CABG to figure out clinical differences such as mortality, postoperative renal function, and thromboembolic events. Overall mortality was 1.5% (n = 41) in the MCPB group and 3.5% (n = 82) in CCPB patients (p < 0.001). Postoperative renal failure and hemodialysis occurred in 2.6% (n = 72/MCPB) vs. 5.3% (n = 122/CCPB (p < 0.001). Multivariable regression revealed use of CCPB as risk factor for increased mortality (OR 2.01, p = 0.001), renal failure (OR 1.79, p < 0.001), and myocardial infarction (OR 1.98, p < 0.001) comparable to risk factors such as preoperative ventilation (OR 2.26, p = 0.048), diabetes mellitus (OR 1.68, p = 0.001), and cardiogenic shock (OR 3.81, p = 0.002). Body mass index had no effect on the analyzed outcome parameters (OR 0.92, p = 0.002). Propensity score-matching analysis of an expert CABG subgroup revealed CCPB as risk factor for mortality (OR 2.26, p = 0.004) and postoperative hemodialysis (OR 1.74, p = 0.017). Compared to conventional circuits, minimized bypass use in CABG is associated with lower mortality and less postoperative renal failure. A high body mass index is feasible and not a risk factor for MCPB surgery.

Mini-extracorporeal circulation technology, conventional bypass and prime displacement in isolated coronary and aortic valve surgery: a propensity-matched in-hospital and survival analysis

OBJECTIVES

Conventional cardiopulmonary bypass is the most commonly used means of artificial circulation in cardiac surgery. However, it suffers from the effects of haemodilution and activation of inflammatory/coagulation cascades. Prime displacement (PD) can offset haemodilution and mini-extracorporeal technology (MIECT) can offset both. So far, no study has compared all of these modalities together; hence, we compared the outcomes of these 3 modalities at our institution.

METHODS

This was a retrospective analysis of our cardiac surgical database. A total of 9626 patients underwent conventional bypass (CB), 3125 patients underwent a modification of CB, called PD, and 904 underwent MIECT. A 1:1 propensity-matching algorithm was employed using IBM SPSS 24 to match (i) 813 MIECT patients with 813 CB patients and (ii) 717 MIECT patients with 717 PD patients. The patients included coronary artery bypass grafting and valve surgery.

RESULTS

MIECT had significantly (P < 0.05) longer bypass and cross-clamp times compared to CB and PD. MIECT had significantly higher rates of postoperative atrial fibrillation associated with it compared to CB. The mean red cell blood transfusion was significantly lower in the MIECT group compared to the CB group as was the mean platelet transfusion and fresh frozen plasma transfusion. The overall 5-year survival was higher in the MIECT group compared to the CB group (log-rank, P = 0.018). Between the MIECT and the PD groups, we found the incidence of renal failure and gastrointestinal complications to be significantly higher in the PD group compared to the MIECT group.

CONCLUSIONS

MIECT has short-term advantages over CB and PD. However, due to the retrospective limitations of the study, including calendar time bias, a multicentre randomized controlled trial comparing all 3 modalities will be beneficial for the larger cardiac community.

Predictive risk factors of acute kidney injury after on-pump coronary artery bypass grafting

Background

Acute kidney injury (AKI) is a common complication after coronary artery bypass grafting (CABG) and increases the risk of short and long-term morbidity and mortality. The aim of our study is to identify preoperative and intraoperative risk factors for development of AKI after primary isolated on-pump CABG.

Methods

In the retrospective study, 210 consecutive patients who underwent primary isolated on-pump CABG from January 2007 to March 2016 were included. The patients were divided into without AKI group (Group 1) and AKI group (Group 2) after operation. The s-Cr levels were recorded pre and postoperatively. The demographics, preoperative and postoperative data were collected from patient's medical profile and analyzed statistically.

Results

AKI developed in 40.5% of the patients (85 patients out of 210 patients). Age (Group 1; Group 2, 63.7±8.6; 67.2±8.2, P=0.004), body surface area (BSA) (Group 1; Group 2, 1.71±0.16; 1.64±0.16, P=0.003), body weight (Group 1; Group 2, 64.1±10.0; 60.7±10.2, P=0.017) were statistically significant for the development of AKI. However, preoperative hemoglobin, blood urea nitrogen (BUN), creatinine, estimated glomerular filtration rate (eGFR) and C-reactive protein (CRP) were not significant. As intraoperative factors, total pump time (TPT), aortic cross clamp time and transfusion were not significant. Female gender (OR 1.88; P=0.044), preoperative proteinuria (OR 2.711; P=0.011) and emergent operation (OR 2.641; P=0.035) were risk factors in univariate analysis. Preoperative proteinuria (OR 2.396; P=0.035) was only risk factor in multivariate analysis.

Conclusions

Preoperative proteinuria was an independent predictor of postoperative AKI in patients undergoing primary isolated on-pump CABG. The accurate risk prediction of AKI after surgery can help clinicians manage more effectively in high-risk patients.

Predictors of Postoperative Acute Kidney Injury after Coronary Artery Bypass Graft Surgery

Objective

The aims of this study were to identify the risk factors associated with acute kidney injury (AKI) after isolated surgical revascularization with cardiopulmonary bypass and to develop a model to predict the appearance of postoperative AKI.

Methods

A total of 435 adult patients who underwent primary isolated coronary artery bypass graft (CABG) surgery, from 2012 to 2016, in the Clinic University Hospital of Valladolid (Spain) were enrolled. AKI was defined according to the risk, injury, failure, loss, and end-stage (RIFLE) criteria. Data were collected from hospital electronic medical records. Multiple logistic regression analysis was used to identify risk factors.

Results

The prevalence of AKI was 12.4%. Multivariate analysis identified age (odds ratio [OR], 1.056; 95% confidence interval [CI], 1.016-1.098; P=0.005), hypertension (OR, 3.078; 95% CI, 1.151-8.230; P=0.018), low ejection fraction (EF) (OR, 6.785; 95% CI, 2.080-22.135; P=0.001), estimated glomerular filtration rate (eGFR) (OR, 1.017; 95% CI, 1.005-1.028; P=0.014), EuroSCORE II (OR, 1.049; 95% CI, 1.004-1.096; P=0.033), and no intake of calcium-channel blockers (CCB) (OR, 4.892; 95% CI, 1.496-16.025; P=0.022) as risk factors for AKI. These risk factors were included in a model to predict postoperative AKI with an area under a receiver operating characteristic curve of 0.783±0.036 (95% CI, 0.713-0.854; P<0.0001).

Conclusion

Age, hypertension, low EF, eGFR, EuroSCORE II, and no intake of CCB were independent risk factors for postoperative AKI. These factors provide an easy and accurate model to predict postoperative AKI in patients undergoing cardiac surgery.

Conventional or minimized cardiopulmonary bypass support during coronary artery bypass grafting? - An analysis by means of perfusion and body mass index

The use of minimized cardiopulmonary bypass support to reduce the side effects of extracorporeal circulation is still contradictorily discussed. This study compares perfusion operated by conventional (CCPB) and minimized (MCPB) cardiopulmonary bypass support during coronary artery bypass grafting (CABG). This study includes the data of 5164 patients treated at our department between 2004 and 2014. Tissue perfusion during cardiopulmonary bypass support and cardiac arrest was assessed by means of body mass index, hemodilution, blood pressure with corresponding pump flow and venous oxygen saturation, serum lactate, and serum pH. Hemodilution was more pronounced after CCPB: hemoglobin had dropped to 4.47 ± 0.142 g/dL after CCPB and to 2.77 ± 0.148 g/dL after MCPB (P = 0.0022). Despite the higher pump flow in conventional circuits (4.86-4.95 L/min vs. 4.1-4.18 L/min), mean blood pressure was higher during minimized bypass support (53 ± 10 vs. 56 ± 13 mm Hg [aortic clamping], 57 ± 9 vs. 61 ± 12 mm Hg [34°C], 55 ± 9 vs.59 ± 11 mm Hg [aortic clamp removal], P < 0.0001) at all time points. Venous oxygen saturation remained on comparable levels of >70% during both conventional and minimized cardiopulmonary bypass support. The increase in serum lactate was more pronounced after CCPB (8.98 ± 1.28 vs. 3.66 ± 1.25 mg/dL, P = 0.0079), corresponding to a decrease in serum pH to acidotic levels (7.33 ± 0.06 vs. 7.35 ± 0.06, P < 0.0001). These effects were evident in all BMI ranges. Minimized cardiopulmonary bypass support provides efficient perfusion in all BMI ranges and is thus equivalent to conventional circuits.

Efficacy of Statin Therapy Related to Baseline Renal Function in Patients with Rheumatic Heart Disease Undergoing Cardiac Surgery

Background

Renal impairment increases the risk of cardiovascular events and perioperative complications in patients with heart valve disease. This study aimed to determine the perioperative benefit of statin treatment related to baseline renal function in patients with rheumatic heart disease (RHD) who had cardiac surgery.

Methods and Results

We performed a retrospective study on 136 patients with RHD who underwent valve replacement surgery. The mean age of the patients was 56.2 years, 59.6% were female, 8.8% patients had diabetes mellitus, and 27.2% of patients had hypertension. Overall, 3 patients died, 2 underwent reoperation, and 25 underwent thoracentesis during the study period. For patients with renal impairment, there was a higher risk of thoracic puncture (odds ratio [OR]: 3.33; 95% confidence interval [CI]: 1.36, 8.11; P < 0.01) and a longer time of drainage (difference in means: 1; 95% CI: 0.88, 1.12; P < 0.01), intensive care unit (ICU) stay (difference in means: 0.2; 95% CI: 0.17, 0.23; P = 0.02), and hospital stay (difference in means: 6.6; 95% CI: 6.15, 7.05; P < 0.01) compared with normal renal function. Furthermore, statins were associated with a reduction in drainage time (difference in means: −1.50; 95% CI: −1.86, −1.14; P = 0.02), ICU stay (difference in means: −0.30; 95% CI: −0.40, −0.20; P = 0.05), and hospital stay (difference in means: −5.40; 95% CI: −6.57, −4.23; P < 0.01) in patients with renal impairment (interaction, P ≤ 0.05 for all), but not in those with normal renal function.

Conclusion

Statins have a greater clinical benefit in perioperative cardiac surgery with renal impairment. Statins are associated with a comparatively lower risk of thoracic puncture, as well as a reduced trend toward a reduction in drainage time, ICU stay, and hospital stay.

Preoperative blood morphology and incidence of acute kidney injury after on-pump coronary artery bypass grafting - a single-center preliminary report

Introduction

Acute kidney injury (AKI) after coronary artery bypass grafting (CABG) performed in cardiopulmonary bypass (CPB) may complicate the postoperative course and has a negative impact on outcome. In some cases, postoperative AKI develops in spite of normal baseline creatinine concentration and estimated glomerular filtration rate (eGFR).

Aim

To examine whether there is any association between the preoperative blood morphology and incidence of post-operative AKI.

Material and methods

The study involved 62 consecutive patients with the mean age of 64.0 ±7.4 years who underwent CABG in CPB. Before surgery, blood morphology and biochemistry were analyzed. Patients with eGFR below 60 ml/min/1.73 m² were excluded. After the operation, parameters of renal function were checked systematically. Acute kidney injury was defined according to the Acute Kidney Injury Network (AKIN) classification.

Results

Twenty-one (33.9%) patients presented AKI (group AKI), although in the majority of them (n = 16) it was temporary and medical management was enough to cure AKI. Only in 1 (1.6%) case was renal replacement therapy necessary. In group AKI, patients’ preoperative hemoglobin concentration (8.46 ±0.72 mM/l), red blood cell count (4.51 ±0.39 × 10¹²/l) and hematocrit (0.40 ±0.04) were significantly lower (p < 0.05) than in group C (9.07 ±0.57 mM/l; 4.78 ±0.36 × 10¹²/l; 0.43 ±0.03, respectively). Interestingly, the baseline parameters of renal function were comparable between groups.

Conclusions

Hemoglobin concentration and red blood cell counts close to the lower limit of the normal range may enable identification of patients at risk of AKI early after CABG in CPB among individuals with normal preoperative biochemical parameters of renal function.

Cardiac surgery-associated acute kidney injury

Cardiac surgery-associated acute kidney injury (CSA-AKI) is a well-recognized complication resulting with the higher morbid-mortality after cardiac surgery. In its most severe form, it increases the odds ratio of operative mortality 3-8-fold, length of stay in the Intensive Care Unit and hospital, and costs of care. Early diagnosis is critical for an optimal treatment of this complication. Just as the identification and correction of preoperative risk factors, the use of prophylactic measures during and after surgery to optimize renal function is essential to improve postoperative morbidity and mortality of these patients. Cardiopulmonary bypass produces an increased in tubular damage markers. Their measurement may be the most sensitive means of early detection of AKI because serum creatinine changes occur 48 h to 7 days after the original insult. Tissue inhibitor of metalloproteinase-2 and insulin-like growth factor-binding protein 7 are most promising as an early diagnostic tool. However, the ideal noninvasive, specific, sensitive, reproducible biomarker for the detection of AKI within 24 h is still not found. This article provides a review of the different perspectives of the CSA-AKI, including pathogenesis, risk factors, diagnosis, biomarkers, classification, postoperative management, and treatment. We searched the electronic databases, MEDLINE, PubMed, EMBASE using search terms relevant including pathogenesis, risk factors, diagnosis, biomarkers, classification, postoperative management, and treatment, in order to provide an exhaustive review of the different perspectives of the CSA-AKI.

Miniaturized cardiopulmonary bypass in adult cardiac surgery: a clinical update

INTRODUCTION

Cardiopulmonary bypass has undoubtedly been the cornerstone in the rapid development of cardiac surgery, allowing even the performance of procedures beyond the scope of cardiothoracic surgery. Its use however, is associated with significant complications that arise from the mechanical effects of the circuit on circulating blood components as well as the contact of blood with non-endothelial surfaces. Miniature cardiopulmonary bypass systems have been developed in an attempt to minimize these complications. Areas covered: Herein clinical outcomes from the most recent studies in adult cardiac surgery are discussed. The main benefits of miniaturisation as well as potential areas of further application are described. Expert commentary: Data is critically appraised in the context of current guidelines. Finally the need for further basic science in addition to large multi-centre randomized controlled trial data is highlighted.

Use of minimal invasive extracorporeal circulation in cardiac surgery: principles, definitions and potential benefits. A position paper from the Minimal invasive Extra-Corporeal Technologies international Society (MiECTiS)

Minimal invasive extracorporeal circulation (MiECC) systems have initiated important efforts within science and technology to further improve the biocompatibility of cardiopulmonary bypass components to minimize the adverse effects and improve end-organ protection. The Minimal invasive Extra-Corporeal Technologies international Society was founded to create an international forum for the exchange of ideas on clinical application and research of minimal invasive extracorporeal circulation technology. The present work is a consensus document developed to standardize the terminology and the definition of minimal invasive extracorporeal circulation technology as well as to provide recommendations for the clinical practice. The goal of this manuscript is to promote the use of MiECC systems into clinical practice as a multidisciplinary strategy involving cardiac surgeons, anaesthesiologists and perfusionists.

Acute Kidney Injury in Cardiorenal Syndrome Type 1 Patients: A Systematic Review and Meta-Analysis

BACKGROUND

We evaluated the epidemiology and outcome of acute kidney injury (AKI) in patients with cardiorenal syndrome type 1 (CRS-1) and its subgroups: acute heart failure (AHF), acute coronary syndrome (ACS) and after cardiac surgery (CS).

SUMMARY

We performed a systematic review and meta-analysis. CRS-1 was defined by AKI (based on RIFLE, AKIN and KDIGO), worsening renal failure (WRF) and renal replacement therapy (RRT). We investigated the three most common clinical causes of CRS-1: AHF, ACS and CS. Out of 332 potential papers, 64 were eligible - with AKI used in 41 studies, WRF in 25 and RRT in 20. The occurrence rate of CRS-1, defined by AKI, WRF and RRT, was 25.4, 22.4 and 2.6%, respectively. AHF patients had a higher occurrence rate of CRS-1 compared to ACS and CS patients (AKI: 47.4 vs. 14.9 vs. 22.1%), but RRT was evenly distributed among the types of acute cardiac disease. AKI was associated with an increased mortality rate (risk ratio = 5.14, 95% CI 3.81-6.94; 24 studies and 35,227 patients), a longer length of stay in the intensive care unit [LOSICU] (median duration = 1.37 days, 95% CI 0.41-2.33; 9 studies and 10,758 patients) and a longer LOS in hospital [LOShosp] (median duration = 3.94 days, 95% CI 1.74-6.15; 8 studies and 35,227 patients). Increasing AKI severity was associated with worse outcomes. The impact of CRS-1 defined by AKI on mortality was greatest in CS patients. RRT had an even greater impact compared to AKI (mortality risk ratio = 9.2, median duration of LOSICU = 10.6 days and that of LOShosp = 20.2 days).

KEY MESSAGES

Of all included patients, almost one quarter developed AKI and approximately 3% needed RRT. AHF patients experienced the highest occurrence rate of AKI, but the impact on mortality was greatest in CS patients.

Miniaturized versus conventional cardiopulmonary bypass and acute kidney injury after cardiac surgery

Introduction:

Acute kidney injury (AKI) is a serious complication after coronary artery bypass grafting (CABG). There are conflicting reports whether a miniaturized cardiopulmonary bypass (MCPB) system is associated with a lower AKI incidence compared with conventional cardiopulmonary bypass (CCPB). It is unknown if AKI risk factors differ between the two groups. We assessed if MCPB decreases AKI after CABG and compared the risk factors between both groups.

Methods:

Sixty-eight Asian patients presenting for elective CABG at a tertiary heart centre were enrolled. They were randomly assigned to MCPB (n=34) or CCPB group (n=34) and followed up in a single-blinded, prospective, randomized, controlled trial. The primary outcome was Acute Kidney Injury Network stage 1 AKI.

Results:

The AKI incidence was 21.5% and was not significantly different between patients undergoing MCPB versus CCPB (21.9% versus 21.2%, p=0.948). The first CPB haematocrit was independently associated with AKI in the MCPB group (Relative Risk [RR]=0.484, 95% Confidence Interval [CI]=0.268-0.876, p=0.016); post-operative blood loss and inflammation were independently associated with AKI in the CCPB group (RR=1.005, 95%CI=1.003-1.007, p<0.001; RR=1.018, 95%CI=1.010-1.028, p<0.001).

Conclusion:

The MCPB system is not associated with a lower incidence of AKI in Asian patients undergoing CABG. Risk factors for AKI differed between patients using the MCPB and CCPB systems.

Miniaturized extracorporeal circulation versus off-pump coronary artery bypass grafting: a meta-analysis of randomized controlled trials

BACKGROUND

Controversies exist whether off-pump coronary artery bypass (OPCAB) is superior to miniaturized extracorporeal circulation (MECC) in reducing deleterious effects of cardiopulmonary bypass as only a number of smaller randomized controlled trials (RCT) currently provide a limited evidence base. The main purpose of conducting the present meta-analysis was to overcome the expected low power in RCTs in an attempt to establish whether MECC is comparable to OPCAB.

METHODS

A MEDLINE/PubMed search was conducted to identify eligible RCTs. A pooled summary effect estimate was calculated by means of Mantel-Haenszel method.

RESULTS

The search yielded 7 RCTs included in this meta-analysis enrolling 271 patients in the OPCAB group and 279 in the MECC group. The OPCAB and MECC groups were comparable in terms of incidence of in-hospital mortality (Risk Difference [RD] 0.01; 95%CI -0.02, 0.03; P = 0.55; I(2) = 0%), stroke (RD -0.01; 95%CI -0.05, 0.04; P = 0.69; I(2) = 0%), need for renal replacement therapy (RD 0.00; -0.06, 0.06; P = 1; I(2) = 0%), postoperative atrial fibrillation (RD -0.03; -0.17, 0.10; P = 0.64; I(2) = 0%), re-exploration for bleeding (RD -0.01; 95%CI -0.03, 0.02; P = 0.65; I(2) = 0%), transfusion rate (RD -0.01; 95%CI -0.03, 0.02; P = 0.65; I(2) = 0%) and the amount of blood loss (weighted mean difference -25 mL; 95%CI -71, 21; P = 0.28; I(2) = 0%).

CONCLUSIONS

Using a meta-analytic approach, MECC achieves clinical results comparable to OPCAB including postoperative blood loss and blood transfusion requirement. On the basis of our findings, MECC should be considered as a valid alternative to OPCAB in order to reduce surgical morbidity of conventional cardiopulmonary bypass.

Impact of age on early outcome after coronary bypass graft surgery using minimized versus conventional extracorporeal circulation

Background

Objective of this study was to evaluate the impact of age on comparative early outcomes after coronary artery bypass graft surgery (CABG) with minimized (MECC) and conventional extracorporeal circulation (CECC).

Methods

A retrospective age-, gender- and operation-matched cohort analysis between January 2005 and December 2010 with a total of 2274 patients undergoing CABG with MECC (n = 1137; 50%) or CECC was performed. Patients were stratified into 4 groups according to age: <59 years, 60–69 years, 70–79 years, and 80 years of age or older. Outcomes were compared within each age group. Patients with preoperative dialysis were excluded from analysis. Primary endpoint was 30-day mortality.

Results

Patients treated with CECC had a significantly higher mean logistic EuroSCORE (6.3% vs. 5.0%; p < 0.001), a slightly lower rate of preoperative myocardial infarction (46% vs. 51%; p = 0.01) and a higher rate of impaired renal function (eGFR < 60 mL/min/1.73 m2: 24% vs. 20%; p = 0.01) compared to MECC-patients. Left internal mammary artery was significantly used more often in MECC patients (93% vs. 86%; p < 0.001). Cardiopulmonary bypass and aortic-cross clamping time were significantly lower in the MECC group (p < 0.001). Overall 30-day mortality was significantly higher in patients treated with CECC (4.4% vs. 2.2%; p = 0.002). Within the different age groups mortality rates were not significantly different except for patients aged 60–69 years (4.5% vs. 1.8%; p = 0.03). Postoperative requirement of renal replacement therapy (4% vs. 2.2%; p = 0.01), respiratory insufficiency (9.9% vs. 6.6%; P = 0.004) and incidence of low cardiac output syndrome (3% vs. 1.2%; p = 0.003) were significantly increased in patients with CECC. Multivariate analysis identified age (p = 0.005; 95% CI 1.01 to 1.08; OR 1.05) among other parameters as an independent risk factor, whereas conventional extracorporeal circulation itself did not present as an independent risk factor for 30-day mortality.

Conclusions

In this matched study sample early outcome was significantly better in patients with MECC compared to CECC, irrespective of age. Prior myocardial infarction estimated GFR < 60 mL and waiving the use of LIMA were independent risk factors for 30-day mortality, which were more present in the CECC group.

Perfusionist techniques of reducing acute kidney injury following cardiopulmonary bypass: an evidence-based review

Cardiac surgery utilizing cardiopulmonary bypass has come a long way since its introduction nearly 60 years ago. In the early days, end-organ damage was linked to contact of the blood with the extracorporeal circuit. One potential cardiac surgery complication known to result in significant morbidity and mortality is acute kidney injury (AKI). Causes of AKI are multifaceted, but most of them are associated with techniques that perfusionists employ during extracorporeal circuit management. These can cause patients to either go on dialysis or renal replacement therapy. Patients with AKI have longer lengths of stay and consume significant resources beyond those with normal kidney function. Few current evidence-based markers determine if the kidneys are adequately protected during surgery. Most relevant literature does not address perfusion-specific techniques that reduce the incidence of AKI. This paper reviews the pathophysiology of the kidney and focuses on perfusion techniques that may reduce the incidence of AKI.

Impact of minimized extracorporeal circulation on outcome in patients with preoperative anemia undergoing coronary artery bypass surgery

Preoperative anemia and low hematocrit during cardiopulmonary bypass have been associated with worse outcome in patients undergoing cardiac surgery. The minimized extracorporeal circulation (MECC) allows a reduction of the negative effects associated with conventional extracorporeal circulation (CECC). In this study, the impact of the MECC on outcome of anemic patients after coronary artery bypass grafting (CABG) was assessed. Between January 2004 and December 2011, 1,945 consecutive patients with preoperative anemia underwent isolated CABG using CECC (44.8%) or MECC (55.2%). The cutoff point for anemia was 13 g/dl for men and 12 g/dl for women. The postoperative creatine kinase and lactate levels were significantly lower in the MECC group (p < 0.001). There was no difference in postoperative blood loss between the groups. However, the intraoperative and postoperative transfusion requirements were significantly lower in the MECC group (p < 0.05). Furthermore, MECC patients had lower incidences of postoperative acute renal failure, and low cardiac output syndrome, shorter intensive care unit lengths of stay and reduced 30-day mortality (p < 0.05). In conclusion, a reduced postoperative mortality, lower transfusion requirements, and less renal and myocardial damage encourage the use of MECC for CABG, especially in the specific high-risk subgroup of patients with anemia.

Cardiac surgery-associated acute kidney injury

Cardiac surgery-associated acute kidney injury (CSA-AKI) is a common and serious postoperative complication of cardiac surgery requiring cardiopulmonary bypass (CPB), and it is the second most common cause of AKI in the intensive care unit. Although the complication has been associated with the use of CPB, the etiology is likely multifactorial and related to intraoperative and early postoperative management including pharmacologic therapy. To date, very little evidence from randomized trials supporting specific interventions to protect from or prevent AKI in broad cardiac surgery populations has been found. The definition of AKI employed by investigators influences not only the incidence of CSA-AKI, but also the identification of risk variables. The advent of novel biomarkers of kidney injury has the potential to facilitate the subclinical diagnosis of CSA-AKI, the assessment of its severity and prognosis, and the early institution of interventions to prevent or reduce kidney damage. Further studies are needed to determine how to optimize cardiac surgical procedures, CPB parameters, and intraoperative and early postoperative blood pressure and renal blood flow to reduce the risk of CSA-AKI. No pharmacologic strategy has demonstrated clear efficacy in the prevention of CSA-AKI; however, some agents, such as the natriuretic peptide nesiritide and the dopamine agonist fenoldopam, have shown promising results in renoprotection. It remains unclear whether CSA-AKI patients can benefit from the early institution of such pharmacologic agents or the early initiation of renal replacement therapy.

Anti-inflammatory strategies to reduce acute kidney injury in cardiac surgery patients: a meta-analysis of randomized controlled trials

Acute kidney injury (AKI) after cardiac operations is a serious complication associated with postoperative mortality. Multiple factors contribute to AKI development, principally ischemia-reperfusion injury and inflammatory response. It is well proven that glucocorticoid administration, leukocyte filter application, and miniaturized extracorporeal circuits (MECC) modulate inflammatory response. We conducted a systematic review of randomized controlled trials (RCTs) in which one of these inflammatory system modulation strategies was used, with the aim to evaluate the effects on postoperative AKI. MEDLINE and Cochrane Library were screened through November 2011 for RCTs in which an inflammatory system modulation strategy was adopted. Included were trials that reported data about postoperative renal outcomes. Because AKI was defined by different criteria, including biochemical determinations, urine output, or dialysis requirement, we unified renal outcome as worsening renal function (WRF). We identified 14 trials for steroids administration (931 patients, WRF incidence [treatment vs. placebo]: 2.7% vs. 2.4%; OR: 1.13; 95% CI: 0.53-2.43; P = 0.79), 9 trials for MECC (947 patients, WRF incidence: 2.4% vs. 0.9%; OR: 0.47; 95% CI: 0.18-1.25; P = 0.13), 6 trials for leukocyte filters (374 patients, WRF incidence: 1.1% vs. 7.5%; OR: 0.18; 95% CI: 0.05-0.64; P = 0.008). Only leukocyte filters effectively reduced WRF incidence. Not all cardiopulmonary bypass-related anti-inflammatory strategies analyzed reduced renal damage after cardiac operations. In adult patients, probably other factors are predominant on inflammation in determining AKI, and only leukocyte filters were effective. Large multicenter RCTs are needed in order to better evaluate the role of inflammation in AKI development after cardiac operations.

Minimal extracorporeal circulation reduces the incidence of postoperative major adverse events after elective coronary artery bypass grafting in high-risk patients. A single-institutional prospective randomized study

Coronary artery bypass grafting (CABG) using minimal extracorporeal circulation (MECC) has been associated with an improved short-term clinical outcome compared to conventional extracorporeal circulation (CECC). The aim of this study was to evaluate the impact of MECC compared to CECC on postoperative major adverse events in high-risk patients undergoing elective coronary revascularization procedures. Two hundred patients undergoing elective CABG were randomized into two groups. In Group A (n=100), MECC was used while Group B (n=100) included patients who were operated on CECC. The incidence of postoperative major adverse events (myocardial infarction, renal failure, stroke, death) was the primary end-point of the study. MECC was associated with a 77% relative risk reduction in the incidence of major adverse events compared to CECC (p=0.004). The rate of major adverse events occurring in the high-risk patient subgroup (preoperative left ventricular ejection fraction ≤40%, age >65 years, EuroSCORE II >5) operated on with MECC was significantly lower in comparison to their CECC counterparts. Based on our results, cardiac centres should be encouraged to use MECC as the standard circuit when performing elective coronary procedures, even in a high-risk population.

The early inflammatory response in a mini-cardiopulmonary bypass system: a prospective randomized study

OBJECTIVE

The aim of this study was to compare the early systemic inflammatory response of the Resting Heart System (RHS; Medtronic, Minneapolis, MN USA), a miniaturized cardiopulmonary bypass (CPB) system, with two groups using a standard extracorporeal circulation system during on-pump coronary artery bypass grafting (CABG) surgery.

METHODS

A total of 60 consecutive patients requiring CABG were prospectively randomized to undergo on-pump CABG using conventional CPB without cardiotomy suction (group A), conventional CPB with cardiotomy suction (group B), or the RHS (group C). Blood samples were collected at five time points: immediately before CPB, 30 minutes into CPB, immediately at the end of CPB, 30 minutes post-CPB, and 1 hour post-CPB. Inflammation was analyzed by changes in (a) levels of plasma proteins, including inflammatory cytokines (interleukin-6 [IL-6], IL-10, and tumor necrosis factor-α), chemokines (IL-8, monokine induced by interferon-γ, monocyte chemotactic protein-1, regulated on activation normal T cell expressed and secreted, and interferon-inducible protein-10), and acute phase proteins (C-reactive protein and complement protein 3); (b) biochemical variables (cardiac troponin I, hematocrit, and immunoglobulin G); and (c) cell numbers (leukocytes, neutrophils, and thrombocytes).

RESULTS

The RHS showed more delayed secretion of the cytokines tumor necrosis factor-α and IL-10, chemokines monokine induced by interferon-γ (P < 0.001); IL-8, and interferon-inducible protein-10; and complement protein 3 than conventional CPB systems did. Median thrombocyte numbers were higher in the RHS group. Levels of cardiac troponin I, monocyte chemotactic protein-1, and IL-6 were lower in both the RHS and conventional CPB without suction than with suction. Levels of C-reactive protein and regulated on activation normal T cell expressed and secreted, plus leukocyte and neutrophil numbers, were similar in all groups.

CONCLUSIONS

The Medtronic RHS may induce less systemic inflammation than conventional CPB systems, particularly when cardiotomy suction was used, but it did not result in improved clinical benefit.

Initial results of an optimized perfusion system

BACKGROUND

In order to reduce the negative effects of extracorporeal circulation (ECC), the perfusion system and management were optimized at our institution. The goals of optimization were a reduction in the priming volume, in the foreign surface area and in microbubble activity, as well as optimization of suction blood management.

METHODS

Sixty patients were included in this retrospective study. Patients were assigned to two groups, with regard to the use of an optimized perfusion system (OPS-group, n=30) and a standard perfusion system (SPS-group, n=30). All patients underwent elective procedures.

RESULTS

There were no significant differences with respect to patient demographics and operation time. ECC time and cross-clamp time were significantly longer in the OPS group. Statistically significant differences in outcome between the two groups were seen with regard to the following variables: effective priming volume (OPS: 775±447ml; SPS: 1610±0ml; p<0.0001), hemoglobin drop after the start of ECC (OPS: 2.7±1.2g/dl; SPS: 4.2±0.8g/dl; p<0.0001), c-reactive protein on postoperative day 2 (OPS: 121.0±59.4 U/l; SPS: 164.0±50.2 U/l; p=0.003). With regard to the use of blood transfusions, a 33% reduction in the overall amount of transfused units was seen. The rate of patients without transfusions during the entire hospital stay increased from 37% (SPS) to 53% (OPS). The mean transfused red blood cell units per patient was lower in the OPS-group (1.6±2.4 units) than in the SPS-group (2.3±3.5 units).

CONCLUSION

With the described optimized perfusion system, a significantly lower priming volume, leading to less hemodilution after the onset of CPB, was achieved. The amount of blood transfusions and the inflammatory response were reduced.

Coronary artery bypass grafting in patients with type 2 diabetes mellitus: a comparison between minimized and conventional extracorporeal circulation

Diabetes mellitus (DM) is an established independent risk factor for significant morbidity and mortality after coronary artery bypass grafting (CABG). The minimized extracorporeal circulation (MECC) allows a reduction of the negative effects associated with conventional extracorporeal circulation (CECC). In this study, the impact of the MECC on outcome of diabetic patients after CABG was assessed. Between January 2002 and December 2009, 1,184 patients with DM underwent elective isolated CABG using CECC (54.6%) or MECC (45.4%). All analysis was performed retrospectively. The extracorporeal circulation time was significantly reduced during MECC procedure. The postoperative increase of creatine kinase and lactate levels was significantly weaker in the MECC group (p < 0.001). Also, the transfusion requirements were significantly lower (p < 0.001). Furthermore, MECC patients had lower incidences of postoperative acute renal failure and sternal wound infections and shorter ICU and hospital lengths of stay (p < 0.05). Moreover, 30-day mortality was significantly reduced in the MECC group (p < 0.05). In conclusion, CABG surgery using MECC system is a safe alternative in patients with DM. A reduced postoperative mortality and lengths of stay, lower transfusion requirements, less renal and myocardial damage, and lower incidence of sternal wound infections encourage the usage of MECC system, especially in high-risk patients.

A case-controlled evaluation of the Medtronic Resting Heart System compared with conventional cardiopulmonary bypass in patients undergoing isolated coronary artery bypass surgery

The Medtronic Resting Heart System (RHS) is a heparin-coated, closed perfusion circuit. Clinical results indicate less haemodilution and reduced complement activation, when compared with a traditional circuit leading to fewer postoperative blood transfusions. We evaluated the potential clinical benefits, including reduced transfusion requirements, when using the RHS compared with conventional cardiopulmonary bypass (cCPB). The study group (n = 330) consisted of patients undergoing isolated coronary artery bypass grafting (CABG) using the RHS system during 2005-2009, matched with a control group (n = 609) including patients operated for isolated CABG during 2002-2009, utilizing cCPB. Significantly fewer patients received peri- and postoperative blood transfusions in the RHS group (25 vs. 37%, P < 0.001; mean 1.0 ± 2.6 vs. mean 1.6 ± 2.9 units of packed red blood cells). The incidence of reoperations due to bleeding was low, RHS 2% (n = 8) vs. cCPB 5% (n = 29), with a trend towards no significant difference between groups (P = 0.079). The duration of mechanical ventilation was shorter (mean 7 ± 16 vs. 9 ± 12 h, P < 0.001) for patients in the RHS group. This study demonstrates that CABG performed with the RHS reduces the incidence and magnitude of allogenic blood transfusion and results in a satisfactory clinical outcome.

2011 update to the Society of Thoracic Surgeons and the Society of Cardiovascular Anesthesiologists blood conservation clinical practice guidelines

BACKGROUND

Practice guidelines reflect published literature. Because of the ever changing literature base, it is necessary to update and revise guideline recommendations from time to time. The Society of Thoracic Surgeons recommends review and possible update of previously published guidelines at least every three years. This summary is an update of the blood conservation guideline published in 2007.

METHODS

The search methods used in the current version differ compared to the previously published guideline. Literature searches were conducted using standardized MeSH terms from the National Library of Medicine PUBMED database list of search terms. The following terms comprised the standard baseline search terms for all topics and were connected with the logical 'OR' connector--Extracorporeal circulation (MeSH number E04.292), cardiovascular surgical procedures (MeSH number E04.100), and vascular diseases (MeSH number C14.907). Use of these broad search terms allowed specific topics to be added to the search with the logical 'AND' connector.

RESULTS

In this 2011 guideline update, areas of major revision include: 1) management of dual anti-platelet therapy before operation, 2) use of drugs that augment red blood cell volume or limit blood loss, 3) use of blood derivatives including fresh frozen plasma, Factor XIII, leukoreduced red blood cells, platelet plasmapheresis, recombinant Factor VII, antithrombin III, and Factor IX concentrates, 4) changes in management of blood salvage, 5) use of minimally invasive procedures to limit perioperative bleeding and blood transfusion, 6) recommendations for blood conservation related to extracorporeal membrane oxygenation and cardiopulmonary perfusion, 7) use of topical hemostatic agents, and 8) new insights into the value of team interventions in blood management.

CONCLUSIONS

Much has changed since the previously published 2007 STS blood management guidelines and this document contains new and revised recommendations.