Liberal or restrictive transfusion after cardiac surgery

Audit of transfusion among the oldest old: treading the fine line between undertransfusion and optimum trigger

BACKGROUND

Recent research has questioned restrictive transfusion policies in vulnerable elderly populations. Our audit assesses the prevalence and postoperative outcomes of extremely elderly patients undergoing the stress of surgery with perioperative hemoglobin (Hb) less than 9 g/dL.

STUDY DESIGN AND METHODS

This retrospective analysis of prospectively collected data addressed patients aged 85+ undergoing elective surgery. Demographic data and baseline characteristics were recorded, as well as Hb and transfused red blood cell (RBC) units. The main endpoint was the prevalence of perioperative Hb less than 9 g/dL, that is, patients with baseline Hb <9 g/dL without preoperative transfusions (defined as Group A). Patients with perioperative Hb of 9 g/dL or greater (with or without transfusion) were designated as Group B. Secondary outcomes included morbidity, length of hospital stay, and mortality 30 days and 6 months after surgery. A bivariate analysis was performed followed by logistic regression to determine whether undergoing the stress of surgery with perioperative Hb less than 9 g/dL was an independent risk factor for postoperative outcomes.

RESULTS

A total of 148 patients were included. The prevalence of perioperative Hb less than 9 g/dL was 25%. It was associated with increased morbidity and mortality -both 30 days and 6 months after surgery- and a prolonged length of hospital stay. Anemia-associated complications were higher among patients from Group A, whereas transfusion-associated ones were evenly distributed. In all the regression models, perioperative Hb less than 9 g/dL was an independent risk factor for worse postoperative outcomes.

CONCLUSION

Perioperative Hb less than 9 g/dL was common among patients aged 85+, and it was associated with increased risk of adverse postoperative outcomes. The tolerance to anemia might decrease perioperatively when Hb is less than 9 g/dL. Thus, less restrictive thresholds deserve further evaluation.

Acute kidney injury after cardiac surgery: prevalence, impact and management challenges

Acute kidney injury (AKI) is a major medical problem that is of particular concern after cardiac surgery. Perioperative AKI is independently associated with an increase in short-term morbidity, costs of treatment, and long-term mortality. In this review, we explore the definition of cardiac surgery-associated acute kidney injury (CSA-AKI) and identify diverse mechanisms and risk factors contributing to the renal insult. Current theories of the pathophysiology of CSA-AKI and description of its clinical course will be addressed in this review. Data on the most promising renal protective strategies in cardiac surgery, from well-designed studies, will be scrutinized. Furthermore, diagnostic tools such as novel biomarkers of AKI and their potential utility will be discussed.

Anemia at Discharge in Elderly Trauma Patients is Not Associated with Six-Month Mortality

Few studies have evaluated outcomes in geriatric trauma patients discharged with anemia. Our hypothesis was that anemia at discharge was not associated with six-month mortality. A 22-month retrospective study of trauma patients ≥ 65 years was conducted from 2015 to 2016. The end point was six-month mortality. The degree of anemia at admission (admission hemoglobin [AHb]) and discharge (discharge hemoglobin [DHb]) was categorized as follows based on hemoglobin (Hb) (g/dL): I (>10), II (>9 and ≤10), III (>8 and ≤9), and IV (≤8). Univariate analysis and multivariate analysis were performed to determine the association of AHb and DHb with the end point. Nine hundred forty-nine patients were analyzed (median age, 82 years). Six-month mortality was 11 per cent. Mortality was associated with AHb by univariate analysis (I:10% [84/831]; II: 13% [9/67]; III: 22% [7/32]; and IV: 26% [5/19]) ( P = 0.003). DHb was not associated with mortality (I:11% [65/613]; II: 12% [21/183]; III: 10% [12/116]; and IV: 18% [7/39]) ( P = 0.37). Logistic regression found that AHb category IV, age, and chronic kidney disease were independently associated with the end point. In geriatric patients, the severity of anemia at admission and not at discharge predicted six-month mortality. Discharging patients with an Hb of ≤8 g/dL was not adversely associated with mortality.

Safety of a Restrictive versus Liberal Approach to Red Blood Cell Transfusion on the Outcome of AKI in Patients Undergoing Cardiac Surgery: A Randomized Clinical Trial

BACKGROUND

Safely reducing red blood cell transfusions can prevent transfusion-related adverse effects, conserve the blood supply, and reduce health care costs. Both anemia and red blood cell transfusion are independently associated with AKI, but observational data are insufficient to determine whether a restrictive approach to transfusion can be used without increasing AKI risk.

METHODS

In a prespecified kidney substudy of a randomized noninferiority trial, we compared a restrictive threshold for red blood cell transfusion (transfuse if hemoglobin<7.5 g/dl, intraoperatively and postoperatively) with a liberal threshold (transfuse if hemoglobin<9.5 g/dl in the operating room or intensive care unit, or if hemoglobin<8.5 g/dl on the nonintensive care ward). We studied 4531 patients undergoing cardiac surgery with cardiopulmonary bypass who had a moderate-to-high risk of perioperative death. The substudy's primary outcome was AKI, defined as a postoperative increase in serum creatinine of ≥0.3 mg/dl within 48 hours of surgery, or ≥50% within 7 days of surgery.

RESULTS

Patients in the restrictive-threshold group received significantly fewer transfusions than patients in the liberal-threshold group (1.8 versus 2.9 on average, or 38% fewer transfusions in the restricted-threshold group compared with the liberal-threshold group; P<0.001). AKI occurred in 27.7% of patients in the restrictive-threshold group (624 of 2251) and in 27.9% of patients in the liberal-threshold group (636 of 2280). Similarly, among patients with preoperative CKD, AKI occurred in 33.6% of patients in the restrictive-threshold group (258 of 767) and in 32.5% of patients in the liberal-threshold group (252 of 775).

CONCLUSIONS

Among patients undergoing cardiac surgery, a restrictive transfusion approach resulted in fewer red blood cell transfusions without increasing the risk of AKI.

Low vs high hemoglobin trigger for transfusion in vascular surgery: a randomized clinical feasibility trial

Current guidelines advocate to limit red blood cell (RBC) transfusion during surgery, but the feasibility and safety of such a strategy remain unclear, as the majority of evidence is based on postoperatively stable patients. We assessed the effects of a protocol aiming to restrict RBC transfusion throughout hospitalization for vascular surgery. Fifty-eight patients scheduled for lower limb bypass or open abdominal aortic aneurysm repair were randomly assigned, on hemoglobin drop below 9.7 g/dL, to either a low-trigger (hemoglobin &lt; 8.0 g/dL) or a high-trigger (hemoglobin &lt; 9.7 g/dL) group for RBC transfusion. Near-infrared spectroscopy assessed intraoperative oxygen desaturation in brain and muscle. Explorative outcomes included nationwide registry data on death and major vascular complications. The primary outcome, mean hemoglobin within 15 days of surgery, was significantly lower in the low-trigger group, at 9.46 vs 10.33 g/dL in the high-trigger group (mean difference, −0.87 g/dL; P = .022), as were units of RBCs transfused (median [interquartile range (IQR)], 1 [0-2] vs 3 [2-6]; P = .0015). Although the duration and magnitude of cerebral oxygen desaturation increased in the low-trigger group (median [IQR], 421 [42-888] vs 127 [11-331] minutes × %; P = .0036), muscle oxygenation was unaffected. The low-trigger group associated to a higher rate of death or major vascular complications (19/29 vs 8/29; hazard ratio, 3.20; P = .006) and fewer days alive outside the hospital within 90 days (median [IQR], 76 [67-82] vs 82 [76-84] days; P = .049). In conclusion, a perioperative protocol restricting RBC transfusion successfully separated hemoglobin levels and RBC units transfused. Exploratory outcomes suggested potential harm with the low-trigger group and warrant further trials before such a strategy is universally adopted. This trial was registered at www.clinicaltrials.gov as #NCT02465125.

Can venous cannula design influence venous return and negative pressure with a minimally invasive extracorporeal circulation?

INTRODUCTION

Recent advances to make cardiopulmonary bypass more physiological include the use of kinetic-assisted venous drainage but without a venous reservoir. Despite manipulation of intravascular volume and patient positioning, arterial flow is frequently reduced. Negative venous line pressures can be generated, which may elicit gaseous microemboli. We investigated the influence of venous cannula design on venous return and negative venous line pressures.

METHODS

In a single-centre, single-surgeon, prospective, randomized, double-blind trial, 48 patients undergoing isolated coronary artery, aortic valve or combined coronary artery and aortic valve surgery, with a minimally invasive circuit, were randomized to a conventional two-stage (2S) or three-stage venous cannula (3S), or to a three-stage venous cannula with additional 'fenestrated' ridges (F3S). Blood flow, venous line pressures and gaseous microemboli number and size were measured.

RESULTS

The pump flow achieved was the same between groups, but in each case fell below the target range of 2.2-2.4 L min^-1 m^-2. The three-stage cannula recorded significantly lower negative pressure than the other cannulae. The total count and volume of gaseous emboli detected with the F3S cannulae was very high in some cases, with wide heterogeneity.

DISCUSSION

The low negative pressures recorded with three-stage cannula, despite having a larger drainage orifice area, suggest that negative pressure may be more influenced by lumen diameter and vena cava collapse rather than drainage hole size. The additional fenestrations resulted in flow characteristics and negative pressures similar to the larger two-stage cannula but are associated with generation of gaseous microemboli.

Post-transfusion hemoglobin values and patient blood management

OBJECTIVES

The objective of this retrospective study was to evaluate the added value of communicating post-transfusion hemoglobin values to clinicians as a strategy to improve RBC utilization in a 500-bed hospital.

METHODS

The total number of RBC transfusions, the mean number of RBC units transfused per patient, the mean pre- and post-transfusion hemoglobin values, the ratio of patients transfused and the ratio of patients with a post-transfusion hemoglobin > 10.5 g/dL were calculated per service and per department for six months. The data were reported to each service and compared with the data of the department as peer group. The impact of this communication strategy was evaluated in the following six months.

RESULTS

In the six months pre-intervention, the mean post-transfusion hemoglobin value was 9.2 g/dL. Post-transfusion hemoglobin was > 10.5 g/dL in 13.4% of patients (112/835). Following communication of these data, RBC consumption decreased 21.0% (p < 0.01) and 21% (p < 0.01) fewer patients received transfusions despite an increase in mean post-transfusion hemoglobin value to 9.4 g/dL (p < 0.01).

CONCLUSION

Providing feedback on post-transfusion hemoglobin data and the global consumption of RBC units to prescribing physicians can be an additional, feasible and effective strategy to encourage self-assessment and to improve blood utilization.

The association of inpatient blood utilization and diagnosis-related group weight: implications for risk-adjusted benchmarking

BACKGROUND

Risk-adjusted benchmarking could be useful to compare blood utilization between hospitals or individual groups, such as physicians, while accounting for differences in patient complexity. The aim of this study was to analyze the association of red blood cell (RBC) use and diagnosis-related group (DRG) weights across all inpatient hospital stays to determine the suitability of using DRGs for between-hospital risk-adjusted benchmarking. Specific hierarchical organizational units (surgical vs. nonsurgical patients, departments, and physicians) were also evaluated.

STUDY DESIGN AND METHODS

We studied blood use among all adult inpatients, and within organizational units, over 4 years (May 2014 to March 2018) at an academic center. Number of RBCs transfused, all patient refined (APR)-DRGs, and other variables were captured over entire hospital stays. We used multilevel generalized linear modeling (zero-inflated negative binomial) to study the relationship between RBC utilization and APR-DRG.

RESULTS

A total of 97,955 hospital stays were evaluated and the median APR-DRG weight was 1.2. The association of RBCs transfused and APR-DRG weight was statistically significant at all hierarchical levels (incidence rate ratio = 1.22; p < 0.001). The impact of APR-DRG on blood use, measured by the incidence rate ratio, demonstrated an association at the all-patient and surgical levels, at several department and physician levels, but not at the medical patient level. The relationship between RBCs transfused and APR-DRG varied across organizational units.

CONCLUSION

Number of RBCs transfused was associated with APR-DRG weight at multiple hierarchical levels and could be used for risk-adjusted benchmarking in those contexts. The relationship between RBC use and APR-DRG varied across organizational units.

Greater anemia tolerance among hospitalized females compared to males

BACKGROUND

Although females have a lower baseline hemoglobin (Hb) compared to males, it is unknown whether females have a greater tolerance for anemia when hospitalized. We tested the hypothesis that females tolerate severe anemia better than males, with decreased inpatient mortality in this setting.

STUDY DESIGN AND METHODS

We conducted a retrospective cohort study in 230,644 adult patients admitted to Johns Hopkins Hospital from January 2009 to June 2016. The relationships between nadir Hb and percentage change in Hb with inpatient mortality were assessed for nontransfused males and females. A multivariable logistic regression was used to determine risk-adjusted differences between males and females for the likelihood of inpatient mortality at nadir Hb levels of 5, 6, and 7 g/dL.

RESULTS

Males had increased mortality when nadir Hb was 6.0 g/dL or less (p < 0.05), whereas females did not. The risk-adjusted likelihood for inpatient mortality was greater for males compared to females at a nadir Hb of 6 g/dL or less (odds ratio, 1.84; 95% confidence interval, 1.09-3.16) (p = 0.02), but this sex-related difference was not significant at a nadir Hb of 5 or 7 g/dL or less. Inpatient mortality increased significantly in both males and females when the percentage decrease in Hb was greater than 50% from baseline (p < 0.05).

CONCLUSIONS

Compared to males, females tolerate a lower nadir Hb, but a similar percentage change in Hb, before an increase in inpatient mortality is recognized. The findings suggest that females may be "preconditioned" to tolerate anemia better than males.

Intra-operative red blood cell transfusion and mortality after cardiac surgery

Background

Anemia in cardiac surgery patients has been associated with poor outcomes. Transfusion of red blood cells during surgery is common practice for perioperative anemia, but may come with risks. Little is known about the association between intra-operative transfusion and mortality in patients undergoing cardiac surgery.

Methods

Single centre historical cohort study in 2933 adult patients undergoing coronary surgery with or without aortic valve replacement from June 2011 until September 2014. To estimate the odds ratio for mortality in patients receiving intra-operative transfusion, a propensity score based logistic regression analysis was performed.

Results

Intra-operative transfusion was associated with a more than three-fold increased risk of 30-day mortality. Patients in the highest quartile of probability of transfusion were older (age 75 vs 66; P <  0.001), had a higher EuroSCORE (6 vs 3; P <  0.001), had lower preoperative hemoglobin levels (7.6 vs 8.9 mmol/l; P < 0.001), had combined surgery more often (CABG + AVR in 33.4% of cases vs 6.6% (P < 0.001) and a longer duration of surgery (224 vs 188 min; P < 0.001). The association between intra-operative transfusion and mortality persisted after adjustment for these risk factors (adjusted OR 2.6; P = 0.007).

Conclusions

Intra-operative transfusion of red blood cells was found to be associated with increased mortality in adults undergoing coronary surgery. Preoperative patient optimization may improve perioperative outcomes by reducing the likelihood of requiring transfusion and thus its associated risk.

Noteworthy Literature Published in 2018 for Cardiothoracic Anesthesiologists

The year 2018 was marked by high-quality, impactful articles spanning the basic, translational, and clinical spectrum in the field of cardiothoracic anesthesia. In this article, we present several hand-picked articles from the past year that we feel were the most significant in shaping our specialty. Large multicenter, randomized controlled trials presenting clinical outcome data dominated the publishing arena: is a restrictive red blood cell transfusion strategy superior to a liberal red blood cell transfusion strategy during cardiopulmonary bypass? Does a low mean arterial blood pressure strategy during cardiopulmonary bypass increase stroke incidence? Does the obesity paradox apply to cardiac surgery? Advancing technology continues to revolutionize our field: can the MitraClip be used to effectively treat secondary mitral regurgitation? Can stem cells improve cardiac function in patients with left ventricular assist devices? These studies allow us to shape our practice in an evidence-based manner, so that we may evolve as a specialty and deliver the best care to our patients.

Minimally invasive versus conventional extracorporeal circulation circuits in patients undergoing coronary artery bypass surgery: a propensity-matched analysis

OBJECTIVES

Minimally invasive extracorporeal circulation circuits provide several advantages compared to conventional extracorporeal circulation circuits. We compared the results of a minimally invasive extracorporeal circulation system with those of conventional extracorporeal circulation system, in patients undergoing isolated coronary artery bypass grafting.

METHODS

We identified 753 consecutive patients who underwent coronary artery bypass grafting at our centre between October 2014 and September 2016. These patients were divided into two groups: a minimally invasive extracorporeal circulation group (M, n = 229) and a conventional extracorporeal circulation group (C, n = 524). Baseline parameters, details of cardiac surgery as well as postoperative complications and outcomes were compared by means of a propensity-matched analysis of 180 matched pairs.

RESULTS

The median EuroSCORE II was 1.3%. Transfusion requirement of packed red blood cells (p = 0.002) was lower in Group M compared to conventional extracorporeal circulation systems. There were no differences in hospital mortality or in rates of adverse events between the matched groups. Total in-hospital mortality of the cohort was 1.7%.

CONCLUSION

The use of minimally invasive extracorporeal circulation is associated with a significantly lower use of blood products after isolated coronary revascularisation. There were no differences concerning duration of surgery, complication rates and mortality between the groups. Therefore, the application of minimally invasive extracorporeal circulation systems should be considered as preferred technique in isolated coronary artery bypass grafting procedures.

[The patient blood management concept : Joint recommendation of the German Society of Anaesthesiology and Intensive Care Medicine and the German Society of Surgery]

Patient blood management is a multimodal concept that aims to detect, prevent and treat anemia, optimize hemostasis, minimize iatrogenic blood loss, and support a patient-centered decision to provide optimal use of allogeneic blood products. Although the World Health Organization (WHO) has already recommended patient blood management as a new standard in 2010, many hospitals have not implemented it at all or only in part in clinical practice. The German Society of Anaesthesiology and Intensive Care Medicine and the German Society of Surgery therefore demand that i) all professionals involved in the treatment should implement important aspects of patient blood management considering local conditions, and ii) the structural, administrative and budgetary conditions should be created in the health care system to implement more intensively many of the measures in Germany.

Restrictive compared with liberal red cell transfusion strategies in cardiac surgery: a meta-analysis

AIMS

To determine whether a restrictive strategy of red blood cell (RBC) transfusion at lower haemoglobin concentrations is inferior to a liberal strategy of RBC transfusion at higher haemoglobin concentrations in patients undergoing cardiac surgery.

METHODS AND RESULTS

We conducted a systematic review, meta-analysis, and trial sequential analysis of randomized controlled trials of the effect of restrictive and liberal RBC transfusion strategies on mortality within 30 days of surgery as the primary outcome. Secondary outcomes were those potentially resulting from anaemia-induced tissue hypoxia and transfusion outcomes. We searched the electronic databases MEDLINE, EMBASE, and the Cochrane Library until 17 November 2017. Thirteen trials were included. The risk ratio (RR) of mortality derived from 4545 patients assigned to a restrictive strategy when compared with 4547 transfused according to a liberal strategy was 0.96 [95% confidence interval (CI) 0.76-1.21, I2 = 0]. A restrictive strategy did not have a statistically significant effect on the risk of myocardial infarction (RR 1.01, 95% CI 0.81-1.26; I2=0), stroke (RR 0.93, 95% CI 0.68-1.27, I2 = 0), renal failure (RR 0.96, 95% CI 0.76-1.20, I2 = 0), or infection (RR 1.12, 95% CI 0.98-1.29, I2 = 0). Subgroup analysis of adult and paediatric trials did not show a significant interaction. At approximately 70% of the critical information size, the meta-analysis of mortality crossed the futility boundary for inferiority of the restrictive strategy.

CONCLUSION

The current evidence does not support the notion that restrictive RBC transfusion strategies are inferior to liberal RBC strategies in patients undergoing cardiac surgery.

The European guideline on management of major bleeding and coagulopathy following trauma: fifth edition

BACKGROUND

Severe traumatic injury continues to present challenges to healthcare systems around the world, and post-traumatic bleeding remains a leading cause of potentially preventable death among injured patients. Now in its fifth edition, this document aims to provide guidance on the management of major bleeding and coagulopathy following traumatic injury and encourages adaptation of the guiding principles described here to individual institutional circumstances and resources.

METHODS

The pan-European, multidisciplinary Task Force for Advanced Bleeding Care in Trauma was founded in 2004, and the current author group included representatives of six relevant European professional societies. The group applied a structured, evidence-based consensus approach to address scientific queries that served as the basis for each recommendation and supporting rationale. Expert opinion and current clinical practice were also considered, particularly in areas in which randomised clinical trials have not or cannot be performed. Existing recommendations were re-examined and revised based on scientific evidence that has emerged since the previous edition and observed shifts in clinical practice. New recommendations were formulated to reflect current clinical concerns and areas in which new research data have been generated.

RESULTS

Advances in our understanding of the pathophysiology of post-traumatic coagulopathy have supported improved management strategies, including evidence that early, individualised goal-directed treatment improves the outcome of severely injured patients. The overall organisation of the current guideline has been designed to reflect the clinical decision-making process along the patient pathway in an approximate temporal sequence. Recommendations are grouped behind the rationale for key decision points, which are patient- or problem-oriented rather than related to specific treatment modalities. While these recommendations provide guidance for the diagnosis and treatment of major bleeding and coagulopathy, emerging evidence supports the author group's belief that the greatest outcome improvement can be achieved through education and the establishment of and adherence to local clinical management algorithms.

CONCLUSIONS

A multidisciplinary approach and adherence to evidence-based guidance are key to improving patient outcomes. If incorporated into local practice, these clinical practice guidelines have the potential to ensure a uniform standard of care across Europe and beyond and better outcomes for the severely bleeding trauma patient.

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.

Red cell transfusion in cardiac surgery: what is the right balance?

KEY IDEAS Patients undergoing cardiac surgery are considered at increased risk of anemia-induced tissue hypoxia and transfusion-associated adverse events. Large recent randomized controlled trials addressing lowering the hemoglobin concentration for red cell transfusion (restrictive strategies) for these patients demonstrated slightly inconsistent results. Combining all randomized trials of restrictive strategies for red cell transfusion in cardiac surgery demonstrated that restrictive transfusion strategies are not inferior to liberal strategies.

The optimal use of blood components in the management of gastrointestinal bleeding

Acute gastrointestinal bleeding accounts for 5,000 deaths per annum in the UK and is the second-most common indication for transfusion of blood components. Transfusion of blood components is integral to management of these patients. Recent years have seen an expansion in the evidence base for their use in this population and this review aims to provide up-to-date guidance on the use of red cells, plasma, platelets, sources of concentrated fibrinogen and adjuncts such as antifibrinolytic agents in patients with acute gastrointestinal haemorrhage. Key considerations include whether or not it is appropriate to extrapolate from studies in trauma patients to the GI bleeding population, whether restrictive red cell transfusion is appropriate for all patients and whether the presence or absence of liver disease has implications for our transfusion practice. Clinical evidence now favours restrictive transfusion of red blood cells in the haemodynamically stable bleeding patient, but there remain significant evidence gaps concerning the use of plasma, platelets and adjunctive measures.

Liberal transfusion strategy to prevent mortality and anaemia-associated, ischaemic events in elderly non-cardiac surgical patients - the study design of the LIBERAL-Trial

Background

Perioperative anaemia leads to impaired oxygen supply with a risk of vital organ ischaemia. In healthy and fit individuals, anaemia can be compensated by several mechanisms. Elderly patients, however, have less compensatory mechanisms because of multiple co-morbidities and age-related decline of functional reserves. The purpose of the study is to evaluate whether elderly surgical patients may benefit from a liberal red blood cell (RBC) transfusion strategy compared to a restrictive transfusion strategy.

Methods

The LIBERAL Trial is a prospective, randomized, multicentre, controlled clinical phase IV trial randomising 2470 elderly (≥ 70 years) patients undergoing intermediate- or high-risk non-cardiac surgery. Registered patients will be randomised only if Haemoglobin (Hb) reaches ≤9 g/dl during surgery or within 3 days after surgery either to the LIBERAL group (transfusion of a single RBC unit when Hb ≤ 9 g/dl with a target range for the post-transfusion Hb level of 9–10.5 g/dl) or the RESTRICTIVE group (transfusion of a single RBC unit when Hb ≤ 7.5 g/dl with a target range for the post-transfusion Hb level of 7.5–9 g/dl). The intervention per patient will be followed until hospital discharge or up to 30 days after surgery, whichever occurs first. The primary efficacy outcome is defined as a composite of all-cause mortality, acute myocardial infarction, acute ischaemic stroke, acute kidney injury (stage III), acute mesenteric ischaemia and acute peripheral vascular ischaemia within 90 days after surgery. Infections requiring iv antibiotics with re-hospitalisation are assessed as important secondary endpoint. The primary endpoint will be analysed by logistic regression adjusting for age, cancer surgery (y/n), type of surgery (intermediate- or high-risk), and incorporating centres as random effect.

Discussion

The LIBERAL-Trial will evaluate whether a liberal transfusion strategy reduces the occurrence of major adverse events after non-cardiac surgery in the geriatric population compared to a restrictive strategy within 90 days after surgery.

Trial registration

ClinicalTrials.gov (identifier: NCT03369210).

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3200-3) contains supplementary material, which is available to authorized users.

Association Between Adverse Clinical Outcomes After Coronary Artery Bypass Grafting and Perioperative Blood Transfusions

Background

Bleeding is a serious complication of coronary artery bypass grafting that often leads to blood transfusion. Approximately 50% of patients who have the surgery receive blood products, and blood transfusions play a role in adverse outcomes after the surgery.

Objective

To examine the association between perioperative blood transfusion and postoperative adverse outcomes in patients undergoing coronary artery bypass grafting.

Methods

A systematic review of the literature, via the matrix method of quality evaluation, was conducted. PubMed, CINAHL, and Science Direct databases for 2000 through 2016 were searched. Inclusion criteria were articles published in English and original research related to clinical outcomes of blood transfusion after coronary artery bypass grafting. Seventeen articles were included in the review.

Results

Mortality, both short- and long-term, was significantly higher in transfusion patients than in nontransfusion patients. Patients with transfusion of red blood cells had higher resource utilization and more complications, including infection, pneumonia, renal failure, graft occlusion, and atrial fibrillation, than did nontransfusion patients.

Conclusion

An association exists between red blood cell transfusions and adverse clinical outcomes for patients undergoing coronary artery bypass grafting. Transfusion of red blood cells is sometimes unnecessary, may be injurious, and should be used cautiously. Even a single-unit increase in perioperative red blood cell transfusions can have a significant adverse impact on outcomes. Individual benefits and risks should be weighed before transfusion to avoid adverse outcomes. Transfusion guidelines should be reviewed to include the latest evidence to guarantee the most appropriate use of blood products.

Predictors of Cardiac Surgery Patients Who Tolerate Blood Conservation in Cardiac Surgery

BACKGROUND

Whether there is a cardiac surgical patient population that does not incur harm from blood conservation is unknown. This study aimed to identify patient characteristics associated with patients who safely tolerate blood conservation.

METHODS

We conducted a retrospective review of consecutive patients undergoing isolated coronary artery bypass graft surgery or isolated aortic valve replacement, or concomitant coronary artery bypass graft surgery and aortic valve replacement between 2011 and 2016, during which blood conservation intervention took place. Logistic regression derived from the preintervention cohort was applied to the postintervention cohort to identify patient characteristics associated with those predicted to be transfused in the preintervention era but were not in the postintervention era.

RESULTS

In this series of 2,701 adult patients undergoing cardiac operations, blood conservation intervention in 2014 led to a 52% reduction in red blood cell transfusion. Between preintervention and postintervention cohorts, there was no significant difference in the measured outcomes. A regression model derived from the preintervention cohort was applied to the postintervention cohort to identify predictors of cohort that do not derive benefit from liberal transfusion. This model demonstrated such patient characteristics to be age more than 75 years (odds ratio [OR] 1.71, 95% confidence interval [CI]: 1.09 to 2.68, p = 0.033), body mass index less than 30 kg/m² (OR 1.5, 95% CI: 1.02 to 2.20, p = 0.044), lowest intraoperative hematocrit between 22 and 25 (OR 1.77, 95% CI: 1.16 to 2.68, p < 0.001), and cardiopulmonary bypass use (OR 4.50, 95% CI: 2.25 to 9.01, p < 0.001).

CONCLUSIONS

Blood conservation can successfully yield reduction in perioperative blood product use, with associated decrease in the risk of postoperative renal failure. A select patient population who may tolerate blood conservation safely was identified, and that may guide a targeted blood conservation effort.

Aortic Valve Replacement Combined with Ascending Aortic Aneurysmectomy in a Patient with Sickle Cell Disease: a Case Report

Sickle cell anemia is a haematological disorder characterized by multiple vaso-occlusive complications, resulting in a reduced life expectancy. These patients are exposed to several triggering factors for sickle cell crises when they are submitted to cardiovascular surgeries with extracorporeal circulation. Therefore, meticulous care and perioperative management are required. This paper reports a successful case of combined cardiovascular surgery - aortic valve replacement and ascending aortic aneurysmectomy - with no serious post-operative complications. In this report, we emphasize the peculiarities of perioperative care in patients with sickle cell anemia.

Trends and Updates on Cardiopulmonary Bypass Setup in Pediatric Cardiac Surgery

Perfusion strategies for cardiopulmonary bypass have direct consequences on pediatric cardiac surgery outcomes. However, inconsistent study results and a lack of uniform evidence-based guidelines for pediatric cardiopulmonary bypass management have led to considerable variability in perfusion practices among, and even within, institutions. Important aspects of cardiopulmonary bypass that can be optimized to improve clinical outcomes of pediatric patients undergoing cardiac surgery include extracorporeal circuit components, priming solutions, and additives. This review summarizes the current literature on circuit components and priming solution composition with an emphasis on crystalloid, colloid, and blood-based primes, as well as mannitol, bicarbonate, and calcium.

Red Blood Cell Transfusion Thresholds in Critically Ill Patients

Anemia of multifactorial etiology is common among critically ill patients and several arbitrary transfusion thresholds have been proposed. Transfusion of red blood cells has been well established to increase morbidity and even mortality among critically ill patients. Several randomized controlled studies have evaluated the use of a restrictive compared to a more liberal transfusion strategy in the critically ill. A transfusion threshold of 7 g/dL appears to be generally safe, especially in the younger age group without significant comorbidities. Besides, a restrictive transfusion strategy reduces the incidence of transfusion-related complications. However, the decision to transfuse needs to be individualized depending on the clinical situation, balancing putative benefits against possible complications.

How to cite this article

Chacko J, Brar G. Red Blood Cell Transfusion Thresholds in Critically Ill Patients. Indian J Crit Care Med 2019;23(Suppl 3):S181-S184.

Red blood cell transfusion and its alternatives in oncologic surgery-A critical evaluation

Although blood transfusions have been used for more than 100 years and their potential to save lives is indisputable, there is still limited data on medium- and long-term outcomes after hemotherapy. Until recently, red blood cell transfusions represented the most commonly employed treatment for cancer anemia. As transfusions have been related to worse patient outcome in oncologic surgery, preventive strategies and alternative treatment approaches in the perioperative setting are warranted. This review aims to evaluate the evidence concerning the impact of transfusion on the course of malignant diseases with a focus on oncologic surgery and to provide a bundle of measures to improve patient care. The perioperative period is pivotal in determining long-term cancer outcome. An increasingly recognized area for improvement during this highly sensitive period is the treatment of anemia for three main reasons: Firstly, anemia has been recognized as an independent predictor of poor prognosis in cancer patients. Secondly, anemia is largely undertreated. Thirdly and probably most importantly, anemia therapy relied and often still relies heavily on red blood cell (RBC) transfusions, which may be an often suboptimal stopgap treatment. Perioperative RBC transfusions should be kept to a minimum due to growing concerns regarding the associated risks, which this review tries to clarify by providing an update of recent literature. This review furthermore discusses treatments for anemia and provides best-practice approaches to improve perioperative management of oncology patients undergoing surgery.

Utility of 4-Factor Prothrombin Complex Concentrate in Trauma and Acute-Care Surgical Patients

Context

Since 2013, prothrombin complex concentrate (PCCs) have been approved in the United States for the reversal of anticoagulation induced by vitamin K antagonists. However, there has been limited investigation into their use in trauma and acute-care surgery (ACS).

Objective

To investigate the role that 4-factor PCC may have in reversing anticoagulation in the setting of trauma and ACS.

Methods

All trauma and ACS patients who presented between March 14, 2014, and August 1, 2015, were included in this retrospective descriptive analysis. Patients receiving 4-factor PCC were compared with patients receiving fresh frozen plasma (FFP) alone. The following data were collected from medical records: age, sex, race, international normalized ratio (INR) at admission (baseline) and after reversal, blood products given, dosing of medication, injury severity score, length of stay, thromboembolic event, death during admission, and death within 90 days after admission.

Results

There were 188 trauma and ACS patients who required reversal of anticoagulation. Of these, 98 patients received FFP and 90 received PCC. Patients who received PCC were at increased risk for death during admission (20% vs 9.2% for FFP group) or within 90 days (39% vs 15%, respectively). Patients in the PCC group had a higher median baseline INR (2.9 vs 2.5 in the FFP group) and a lower postintervention INR (1.4 vs 1.8); consequently, the decrease in INR was greater in the PCC group than in the FFP group (1.5 vs 0.7, respectively). The number of total units of packed red blood cells transfused was significantly higher in patients receiving PCC.

Conclusion

Patients receiving PCC had worse outcomes than those who received FFP. Given that these differences may have resulted from baseline differences between groups, these results mandate further prospective analysis of the use of PCC in trauma and ACS patients.

A Review of Goal-Directed Cardiopulmonary Bypass Management in Pediatric Cardiac Surgery

Cardiopulmonary bypass perfusion management significantly affects postoperative outcomes. In recent years, the principles of goal-directed therapy have been applied to the field of cardiothoracic surgery to improve patient outcomes. Goal-directed therapy involves continuous peri- and postoperative monitoring of vital clinical parameters to tailor perfusion to each patient's specific needs. Closely measured parameters include fibrinogen, platelet count, lactate, venous oxygen saturation, central venous oxygen saturation, mean arterial pressure, perfusion flow rate, and perfusion pulsatility. These parameters have been shown to influence postoperative fresh frozen plasma transfusion rate, coagulation state, end-organ perfusion, and mortality. In this review, we discuss the recent paradigm shift in pediatric perfusion management toward goal-directed perfusion.

Measuring the quality of perioperative care in cardiac surgery

Quality of care is of increasing importance in health and surgical care. In order to maintain and improve quality, we must be able to measure it and identify variation. In this narrative review, we aim to identify measures used in the assessment of quality of care in cardiac surgery and to evaluate their utility. The electronic databases Pubmed/MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), Cochrane Database of Systematic Reviews, and CINAHL were searched for original published studies using the terms 'cardiac surgery' and 'quality or outcome or process or structure' as either keywords in the title or text or MeSH terms. Secondary searches and identification of references from original articles were carried out. We found a total of 54 original articles evaluating measurements of quality. While structure, process, and outcome indicators remain the mainstay of quality measurement, new and innovative methods of risk assessment have improved reliability and discrimination. Continuous assessment provides a promising method of both maintaining and improving quality of care. Future studies should focus on long-term and patient-centred outcomes, such as quality-of-life measures.