Diagnostic criteria for pre-operative anaemia-time to end sex discrimination

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

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

Age-specific sex-differences in cerebral blood flow velocity in relation to haemoglobin levels

INTRODUCTION

Cerebral blood flow (CBF) declines with age and abnormalities in CBF are associated with age-related cerebrovascular disease and neurodegeneration. Women have higher CBF than men, although this sex-difference diminishes to some extent with age in healthy subjects. The physiological drivers of these age/sex differences are uncertain, but might be secondary to age and sex-differences in haemoglobin (Hb) level. Hb levels are inversely correlated with CBF, are lower in women, and decline with age in men, but the interrelations between these factors have not been explored systematically either in healthy subjects or across the full age-range in patients with vascular risk factors. We aimed to determine the age-specific interrelations between sex, Hb, and CBF velocity in a large cohort of patients with cerebrovascular disease.

PATIENTS AND METHODS

In patients with a recent transient ischaemic attack or minor stroke (Oxford Vascular Study) and no ipsilateral or contralateral stenosis of the carotid or intracranial arteries, we related peak-systolic velocity (PSV) and other parameters on transcranial Doppler ultrasound (TCD) of the middle cerebral artery to sex, age, Hb and vascular risk factors.

RESULTS

Of 958 eligible subjects (mean age/SD = 68.04/14.26, 53.2% male), younger women (age < 55 years) had higher CBF velocities than men (mean sex difference in PSV at age < 55 years = 16.31 cm/s; p < 0.001), but this difference declined with age (interaction p < 0.001), such that it was no longer significant at age 75-84 (∆PSV = 3.26 cm/s; p = 0.12) and was reversed at age ⩾ 85 (∆PSV = -7.42 cm/s; p = 0.05). These changes mirrored trends in levels of Hb, which were higher in men at age < 55 (∆Hb = 1.92 g/dL; p < 0.001), but steadily decreased with age in men but not in women (interaction p < 0.001), with no residual sex-difference at age ⩾ 85 (∆Hb = 0.12 g/dL; p = 0.70). There was an inverse correlation between Hb and PSV in both women and men (both p ⩽ 0.01), and the sex-difference in PSV at age < 55 was substantially diminished after adjustment for Hb (∆PSV = 6.92; p = 0.036; ∆PSV = 5.92, p = 0.13 with further adjustment for end-tidal CO2). In contrast, the sex difference in PSV was unaffected by adjustment for systolic and diastolic blood pressure, heart rate, and vascular risk factors (history of hypertension, diabetes, hyperlipidaemia and smoking).

DISCUSSION

CBF velocity is strongly correlated with Hb level at all ages, and sex-differences in CBF velocity appear to be explained in major part by age-related sex-differences in Hb.

Haemoglobin thresholds to define anaemia from age 6 months to 65 years: estimates from international data sources

BACKGROUND

Detection of anaemia is crucial for clinical medicine and public health. Current WHO anaemia definitions are based on statistical thresholds (fifth centiles) set more than 50 years ago. We sought to establish evidence for the statistical haemoglobin thresholds for anaemia that can be applied globally and inform WHO and clinical guidelines.

METHODS

In this analysis we identified international data sources from populations in the USA, England, Australia, China, the Netherlands, Canada, Ecuador, and Bangladesh with sufficient clinical and laboratory information collected between 1998 and 2020 to obtain a healthy reference sample. Individuals with clinical or biochemical evidence of a condition that could reduce haemoglobin concentrations were excluded. We estimated haemoglobin thresholds (ie, 5th centiles) for children aged 6-23 months, 24-59 months, 5-11 years, and 12-17 years, and adults aged 18-65 years (including during pregnancy) for individual datasets and pooled across data sources. We also collated findings from three large-scale genetic studies to summarise genetic variants affecting haemoglobin concentrations in different ancestral populations.

FINDINGS

We identified eight data sources comprising 18 individual datasets that were eligible for inclusion in the analysis. In pooled analyses, the haemoglobin fifth centile was 104·4 g/L (90% CI 103·5-105·3) in 924 children aged 6-23 months, 110·2 g/L (109·5-110·9) in 1874 children aged 24-59 months, and 114·4 g/L (113·6-115·2) in 1839 children aged 5-11 years. Values diverged by sex in adolescents and adults. In pooled analyses, the fifth centile was 122·2 g/L (90% CI 121·3-123·1) in 1741 female adolescents aged 12-17 years and 128·2 g/L (126·4-130·0) in 1103 male adolescents aged 12-17 years. In pooled analyses of adults aged 18-65 years, the fifth centile was 119·7 g/L (90% CI 119·1-120·3) in 3640 non-pregnant females and 134·9 g/L (134·2-135·6) in 2377 males. Fifth centiles in pregnancy were 110·3 g/L (90% CI 109·5-111·0) in the first trimester (n=772) and 105·9 g/L (104·0-107·7) in the second trimester (n=111), with insufficient data for analysis in the third trimester. There were insufficient data for adults older than 65 years. We did not identify ancestry-specific high prevalence of non-clinically relevant genetic variants that influence haemoglobin concentrations.

INTERPRETATION

Our results enable global harmonisation of clinical and public health haemoglobin thresholds for diagnosis of anaemia. Haemoglobin thresholds are similar between sexes until adolescence, after which males have higher thresholds than females. We did not find any evidence that thresholds should differ between people of differering ancestries.

FUNDING

World Health Organization and the Bill & Melinda Gates Foundation.

Preoperative hemoglobin thresholds for increased risk of "medical" complications in fast-track total hip and knee arthroplasty, a secondary analysis of a machine-learning algorithm

BACKGROUND

There is increasing evidence that gender-specific hemoglobin thresholds may not be ideal in the surgical population. Thus, preoperative anemia defined as a hemoglobin of <13.0 g/dL is a well-established risk factor in elective surgery. However, few studies have investigated the specific influence of preoperative hemoglobin within a machine-learning model using data from an optimized fast-track surgical setup.

STUDY DESIGN AND METHODS

A secondary analysis on the specific influence of preoperative hemoglobin level on a machine-learning model developed for identifying patients at increased risk of a length of stay (LOS) of >4 day or readmissions due to medical complications in fast-track total hip and knee arthroplasty within a well-defined fast-track protocol. To evaluate the effect of hemoglobin on the model we calculated SHaply Additive Explanation (SHAP) values for the 3913 patients from our previous test-dataset and stratified by gender and total hip and knee arthroplasty, respectively.

RESULTS

The study period ran from January 2017 to August 2017. Median LOS was 1 day and mean preoperative Hb was 15.5 g/dL (SD:1.5), lower in women (14.9 vs. 16.2 g/dL) and with 30.5% of women versus 12.0% of men having a Hb of <13.0 g/dL. There was a steep increase in SHAP value with a preoperative Hb < 14.8 g/dL, and irrespective of gender age and procedure type.

DISCUSSION

A machine-learning model found a hemoglobin threshold of <14.8 g/dL for increased risk of impaired recovery, regardless of gender or age, supporting reevaluation of preoperative anemia thresholds in the elective surgical setting.

Prevalence and long-term implications of preoperative anemia in patients undergoing elective general surgery: a retrospective cohort study at a university hospital

OBJECTIVE

The aim of this retrospective study was to assess the prevalence of anaemia in a cohort of patients undergoing elective general surgery at a university hospital. Furthermore, the authors investigated the influence of anaemia on short-term and long-term postoperative outcome.

BACKGROUND

Awareness of the negative impact of preoperative anaemia on perioperative morbidity and mortality is rising. Anaemia is a potentially modifiable factor, and its therapy might improve patient outcome in elective surgery. Nevertheless, patients with preoperative anaemia frequently undergo elective surgery without receiving adequate preoperative treatment.

METHODS

In this single-centre cohort study, the authors analyzed 6908 adult patients who underwent elective general surgery. Patients undergoing day-clinic surgery were excluded. In all patients, preoperative haemoglobin concentration and haematocrit was available.

RESULTS

Of all patients analyzed, 32.9% were anaemic (21.0% mild, 11.8% moderate, 1.1% severe). Median time to last follow-up was 5.2 years. During the whole study period, 27.1% of patients died (1.2% died during the hospital stay); median time to death was 1.3 years. Patients with preoperative anaemia had significantly higher mortality rates ( P <0.001) and a higher probability of postoperative complications ( P <0.001). Likewise, receiving blood transfusions was associated with a higher risk of death ( P <0.001).

CONCLUSION

This retrospective single-centre analysis confirmed that preoperative anaemia is common, and is a significant risk factor for unfavourable postoperative outcome. As anaemia is a modifiable risk factor, the implementation of a patient blood management concept is crucial to reduce detrimental postoperative events associated with anaemia.

Statistical haemoglobin thresholds to define anaemia across the lifecycle

Detection of anaemia is critical for clinical medicine and public health. Current WHO values that define anaemia are statistical thresholds (5 ^th centile) set over 50 years ago, and are presently <110g/L in children 6-59 months, <115g/L in children 5-11 years, <110g/L in pregnant women, <120g/L in children 12-14 years of age, <120g/L in non-pregnant women, and <130g/L in men. Haemoglobin is sensitive to iron and other nutrient deficiencies, medical illness and inflammation, and is impacted by genetic conditions; thus, careful exclusion of these conditions is crucial to obtain a healthy reference population. We identified data sources from which sufficient clinical and laboratory information was available to determine an apparently healthy reference sample. Individuals were excluded if they had any clinical or biochemical evidence of a condition that may diminish haemoglobin concentration. Discrete 5 ^th centiles were estimated along with two-sided 90% confidence intervals and estimates combined using a fixed-effect approach. Estimates for the 5 ^th centile of the healthy reference population in children were similar between sexes. Thresholds in children 6-23 months were 104.4g/L [90% CI 103.5, 105.3]; in children 24-59 months were 110.2g/L [109.5, 110.9]; and in children 5-11 years were 114.1g/L [113.2, 115.0]. Thresholds diverged by sex in adolescents and adults. In females and males 12-17 years, thresholds were 122.2g/L [121.3, 123.1] and 128.2 [126.4, 130.0], respectively. In adults 18-65 years, thresholds were 119.7g/L [119.1, 120.3] in non-pregnant females and 134.9g/L [134.2, 135.6] in males. Limited analyses indicated 5 ^th centiles in first-trimester pregnancy of 110.3g/L [109.5, 111.0] and 105.9g/L [104.0, 107.7] in the second trimester. All thresholds were robust to variations in definitions and analysis models. Using multiple datasets comprising Asian, African, and European ancestries, we did not identify novel high prevalence genetic variants that influence haemoglobin concentration, other than variants in genes known to cause important clinical disease, suggesting non-clinical genetic factors do not influence the 5 ^th centile between ancestries. Our results directly inform WHO guideline development and provide a platform for global harmonisation of laboratory, clinical and public health haemoglobin thresholds.

Identification of the haemoglobin level associated with a lower risk of complications after total hip and knee arthroplasty

BACKGROUND

Preoperative anaemia is associated with poor outcomes in surgical patients, but the preoperative haemoglobin cut-off that determines lower morbidity in total knee arthroplasty (TKA) and total hip arthroplasty (THA) is not well established.

METHODS

Planned secondary analysis of data collected during a multicentre cohort study of patients undergoing THA and TKA in 131 Spanish hospitals during a single 2-month recruitment period. Anaemia was defined as haemoglobin <12 g dl-1 for females and < 13 g dl-1 for males. The primary outcome was the number of patients with 30-day in-hospital postoperative complications according to European Perioperative Clinical Outcome definitions and specific surgical TKA and THA complications. Secondary outcomes included the number of patients with 30-day moderate-to-severe complications, red blood cell transfusion, mortality, and length of hospital stay. Binary logistic regression models were constructed to assess association between preoperative Hb concentrations and postoperative complications, and variables significantly associated with the outcome were included in the multivariate model. The study sample was divided into 11 groups based on preoperative Hb values in an effort to identify the threshold at which increased postoperative complications occurred.

RESULTS

A total of 6099 patients were included in the analysis (3818 THA and 2281 TKA), of whom 8.8% were anaemic. Patients with preoperative anaemia were more likely to suffer overall complications (111/539, 20.6% vs. 563/5560, 10.1%, p < .001) and moderate-to-severe complications (67/539, 12.4% vs. 284/5560, 5.1%, p < .001). Multivariable analysis showed preoperative haemoglobin ≥14 g dl-1 was associated with fewer postoperative complications.

CONCLUSION

Preoperative haemoglobin ≥14 g dl-1 is associated with a lower risk of postoperative complications in patients undergoing primary TKA and THA.

Treatment Strategies in Anemic Patients Before Cardiac Surgery

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

Centre for Perioperative Care anaemia guideline: implications for anaesthesia

The Centre for Perioperative Care (CPOC) has published in September 2022 guidance addressing perioperative anaemia. This editorial addresses the definition of anaemia for women and management of borderline anaemia in women. We also address implications of the CPOC guidance for anaesthetists and the future direction of anaemia research and management.

Evaluating variation in perioperative red blood cell transfusion for patients undergoing elective gastrointestinal cancer surgery

BACKGROUND

Patients undergoing gastrointestinal cancer surgery often receive packed red blood cell transfusions. Understanding practice variation is critical to support efforts working toward responsible transfusion use. We measured the extent and importance of variation in perioperative packed red blood cell transfusion use across physicians and hospitals among gastrointestinal cancer surgery patients.

METHODS

We identified patients who underwent elective gastrointestinal cancer resection between 2007 and 2019 using linked administrative health data sets in Ontario, Canada. We used funnel plots to describe variation in transfusion use, adjusted for patient case mix. Hierarchical regression models quantified patient-level, between-physician, and between-hospital variation in transfusion use with R² measures, variance partition coefficients, and median odds ratios.

RESULTS

Of 59,964 included patients (median age 69 years; 43.2% female; 75.8% colorectal resections), 18.0% received perioperative packed red blood cell transfusions. Funnel plots showed variation in transfusion use among physicians and hospitals. Patient characteristics, such as age, comorbidity, and procedure type, combined to explain 12.8% of the variation. After adjusting for case mix, systematic between-physician and between-hospital differences were responsible for 2.8% and 2.1% of the variation, respectively. This translated to an approximately 30% difference in the odds of transfusion for 2 similar patients treated by distinct physicians (median odds ratio: 1.35, 95% confidence interval 1.30-1.40) and hospitals (median odds ratio: 1.30, 95% confidence interval 1.23-1.42). We observed comparable effects across procedure-type subgroups.

CONCLUSION

Transfusion provision is highly driven by patient factors. Yet the impact of the treating physician and hospital on variation relative to other factors is important and reflects opportunities to target modifiable processes of care to standardize perioperative packed red blood cell transfusion practice.

Trends in prevalence and treatment rate of anemia in the U.S. population: cross-sectional study using data from NHANES 2005-2018

OBJECTIVES

To determine the trends in anemia prevalence, treatment rates, and their associated demographic and socioeconomic status factors in the U.S. nationally representative population.

METHODS

We extracted data from individuals ≥20-year-old from the NHANES from 2005 to 2018. The trends of anemia prevalence and treatment were assessed by Cochran-Armitage test. The association between two dependent variables (anemia status and treatment) and demographic were examined by multiple logistic regression.

RESULTS

The general anemia prevalence has a significant increasing trend from 5.71% to 6.86% (P trend<.001) from 2005 to 2018, whereas the trend in general anemia treatment rate was not significant (p = .148). Logistic regression showed that age groups (OR: 2.15for 60 or older vs. 20-39 years old), sex (0.47 for male vs. female), race (0.22 for NHW vs. NHB), education (0.80for some college or AA degree vs. less than high school), PIR (0.60 for ≥3.5 vs.≤1.3), and birthplace (0.88 for U.S. vs. other) were significantly associated with anemia. The factors significantly associated with anemia treatment were age group (1.51 for 60 years and older vs. 20-39 years old), sex (0.53 male vs. female), birthplace (1.88 U.S. vs. other), and insurance (1.80 for Yes vs. No).

CONCLUSION

While there was no significant increase in anemia treatment between 2005 and 2018, the anemia prevalence increased significantly, particularly among individuals with lower income, less education, and born outside the U.S. Moreover, the high anemia prevalence among NHB compared to other races indicated that more resources are needed to reduce disparities.

The prevalence of perioperative iron deficiency anaemia in women undergoing caesarean section-a retrospective cohort study

Background

Caesarean section is a common surgery, with almost 23 million procedures performed globally each year. Postpartum haemorrhage, in association with caesarean section surgery, is a leading global cause of maternal morbidity and mortality. Perioperative iron deficiency anaemia is a risk factor for intraoperative bleeding. Therefore, anaemia is an important and modifiable risk factor for bleeding during caesarean section surgery. Recent recommendations advise that all preoperative patients with anaemia (defined as haemoglobin concentration (Hb) < 130 g/L), regardless of sex, be assessed and treated to normalise haemoglobin levels. It is unclear how this recommendation translates to pregnant women where the World Health Organization (WHO) defines anaemia at a much lower threshold (Hb < 110 g/L). We aimed to determine the prevalence, and characterization, of Hb levels < 130 g/L perioperatively in women undergoing caesarean section.

Method

We conducted a retrospective cohort study of 489 consecutive women who underwent caesarean section over a 12-week period, in a single-centre tertiary referral maternity unit in Australia. We calculated the proportion of women who were anaemic (Hb < 130 g/L) at four time points—first hospital appointment, third trimester, preoperatively and on discharge from hospital. The proportion of women who were iron deficient (ferritin level < 30 μg/L) at their first hospital appointment was determined.

Results

Haemoglobin was measured in 479 women. Ferritin was measured in 437 of these women. The mean (SD) Hb at the first hospital appointment, third trimester, preoperatively, and postoperatively on discharge was 126.7 (11.4) g/L, 114.6 (10.6) g/L, 124.1 (12.4) g/L, and 108.0 (13.6) g/L respectively. Iron deficiency was present in 148 (33.9%) women at their first hospital appointment; 107 of 248 (43.1%) women with anaemia and 41 of 189 (21.7%) with no anaemia. 29 women were found to have moderate anaemia (Hb 80−109 g/L) with 18 of these 29 (62.1%) women having iron deficiency. Only 68 (45.9%) women with iron deficiency at their first hospital appointment received treatment. The prevalence of anaemia classified as Hb < 130 g/L versus the WHO classification of Hb < 110 g/L from all causes was 57.4% versus 6.1% at first hospital appointment, 94% versus 26.1% in third trimester, and 66.0% versus 12.2% preoperatively. Postoperatively at least 40% of women had Hb < 130 g/L on hospital discharge versus at least 23% of women using WHO definition of Hb < 110 g/L. Of the 112 women with hospital discharge Hb < 110 g/L, 35 (31.3%) women were iron deficient at their first hospital appointment.

Conclusion

Over one in three women were iron deficient at their first hospital appointment. 62% of women with moderate anaemia (Hb 80–109 g/L) also had iron deficiency. At least four in 10 women were anaemic (Hb < 130 g/L) on hospital discharge. Less than half of the women with anaemia were treated. Our data suggests that 30% of postoperative anaemia may be prevented with intensive treatment of iron deficiency in early pregnancy. Large prospective studies, are needed to determine outcomes after caesarean section in women, stratified by preoperative Hb and ferritin levels. The prevalence of anaemia in our data suggests it is a moderate public health problem.

Tailoring prehabilitation to address the multifactorial nature of functional capacity for surgery

Mounting evidence suggests that recovery begins before the surgical incision. The pre-surgery phase of recovery - the preparation for optimal surgical recovery - can be reinforced with prehabilitation. Prehabilitation is the approach of enhancing the functional capacity of the individual to enable them to withstand a stressful event. With this narrative review, we apply the Wilson & Cleary conceptual model of patient outcomes to specify the complex and integrative relationship of health factors that limit functional capacity before surgery. To have the greatest impact on patient outcomes, prehabilitation programs require individualized and coordinated care from medical, nutritional, psychosocial, and exercise services. This article is protected by copyright. All rights reserved.

Perioperative Risk Stratification and Modification

This article discusses the important topic of perioperative risk stratification and the interventions that can be used in the perioperative period for risk modification. It begins with a brief overview of the commonly used scoring systems, risk-prediction models, and assessments of functional capacity and discusses some of the evidence behind each. It then moves on to examine how perioperative risk can be modified through the use of shared decision making, management of multimorbidity, and prehabilitation programs, before considering what the future of risk stratification and modification may hold.

Non-erythropoiesis-stimulating agent, non-iron therapies for the management of anaemia: protocol for a scoping review

INTRODUCTION

Preoperative anaemia is associated with poor postoperative outcomes and is the strongest predictor of allogenic blood transfusion, which contributes further to patient morbidity. Emphasis has been placed on correcting anaemia prior to surgery to mitigate these outcomes. Conflicting evidence exists regarding the benefit of currently recommended interventions. With greater understanding of iron haemostasis and erythropoiesis, novel therapies have been identified. These are at varying stages of development with some demonstrating promising results in patients with chronic kidney disease. It is not known how these agents have been studied outside this population, particularly in the perioperative context. To address this, we will conduct a scoping review of the published literature to chart the evidence.

METHODS AND ANALYSIS

The scoping review will be reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews framework. The electronic database search will include Scopus, MEDLINE (Ovid) and Excerpta Medica database (Ovid), with no language restrictions, and will include all publications since 1 January 2010. This review will have three objectives: (1) to describe the mechanisms of action for novel agents, (2) to describe the level of evidence and stage of development of novel agents in a perioperative setting, and (3) to determine the potential agents suitable for prospective controlled trials in a preoperative or postoperative patient cohort and aiming to improve patient-centred outcomes. The review process will involve two reviewers with a third reviewer resolving disagreements. Data will be extracted and organised with subsequent analysis.

ETHICS AND DISSEMINATION

This scoping review does not require research ethics approval. The results will be published in a peer-reviewed journal and inform the development of future prospective trials based on established evidence from potential therapeutic agents.

TRIAL REGISTRATION NUMBER

This protocol has been registered prospectively on the Open Science Framework registry (DOI:10.17605/OSF.IO/SM3UH, https://osf.io/sm3uh/?view_only=39876ccf7a4348dfbd566535b957a7db).Cite Now.

Transfusion thresholds for guiding red blood cell transfusion

BACKGROUND

The optimal haemoglobin threshold for use of red blood cell (RBC) transfusions in anaemic patients remains an active field of research. Blood is a scarce resource, and in some countries, transfusions are less safe than in others because of inadequate testing for viral pathogens. If a liberal transfusion policy does not improve clinical outcomes, or if it is equivalent, then adopting a more restrictive approach could be recognised as the standard of care.  OBJECTIVES: The aim of this review update was to compare 30-day mortality and other clinical outcomes for participants randomised to restrictive versus liberal red blood cell (RBC) transfusion thresholds (triggers) for all clinical conditions. The restrictive transfusion threshold uses a lower haemoglobin concentration as a threshold for transfusion (most commonly, 7.0 g/dL to 8.0 g/dL), and the liberal transfusion threshold uses a higher haemoglobin concentration as a threshold for transfusion (most commonly, 9.0 g/dL to 10.0 g/dL).

SEARCH METHODS

We identified trials through updated searches: CENTRAL (2020, Issue 11), MEDLINE (1946 to November 2020), Embase (1974 to November 2020), Transfusion Evidence Library (1950 to November 2020), Web of Science Conference Proceedings Citation Index (1990 to November 2020), and trial registries (November 2020). We  checked the reference lists of other published reviews and relevant papers to identify additional trials. We were aware of one trial identified in earlier searching that was in the process of being published (in February 2021), and we were able to include it before this review was finalised.

SELECTION CRITERIA

We included randomised trials of surgical or medical participants that recruited adults or children, or both. We excluded studies that focused on neonates. Eligible trials assigned intervention groups on the basis of different transfusion schedules or thresholds or 'triggers'. These thresholds would be defined by a haemoglobin (Hb) or haematocrit (Hct) concentration below which an RBC transfusion would be administered; the haemoglobin concentration remains the most commonly applied marker of the need for RBC transfusion in clinical practice. We included trials in which investigators had allocated participants to higher thresholds or more liberal transfusion strategies compared to more restrictive ones, which might include no transfusion. As in previous versions of this review, we did not exclude unregistered trials published after 2010 (as per the policy of the Cochrane Injuries Group, 2015), however, we did conduct analyses to consider the differential impact of results of trials for which prospective registration could not be confirmed.   DATA COLLECTION AND ANALYSIS: We identified trials for inclusion and extracted data using Cochrane methods. We pooled risk ratios of clinical outcomes across trials using a random-effects model. Two review authors independently extracted data and assessed risk of bias. We conducted predefined analyses by clinical subgroups. We defined participants randomly allocated to the lower transfusion threshold as being in the 'restrictive transfusion' group and those randomly allocated to the higher transfusion threshold as being in the 'liberal transfusion' group.

MAIN RESULTS

A total of 48 trials, involving data from 21,433 participants (at baseline), across a range of clinical contexts (e.g. orthopaedic, cardiac, or vascular surgery; critical care; acute blood loss (including gastrointestinal bleeding); acute coronary syndrome; cancer; leukaemia; haematological malignancies), met the eligibility criteria. The haemoglobin concentration used to define the restrictive transfusion group in most trials (36) was between 7.0 g/dL and 8.0 g/dL.  Most trials included only adults; three trials focused on children. The included studies were generally at low risk of bias for key domains including allocation concealment and incomplete outcome data. Restrictive transfusion strategies reduced the risk of receiving at least one RBC transfusion by 41% across a broad range of clinical contexts (risk ratio (RR) 0.59, 95% confidence interval (CI) 0.53 to 0.66; 42 studies, 20,057 participants; high-quality evidence), with a large amount of heterogeneity between trials (I² = 96%). Overall, restrictive transfusion strategies did not increase or decrease the risk of 30-day mortality compared with liberal transfusion strategies (RR 0.99, 95% CI 0.86 to 1.15; 31 studies, 16,729 participants; I² = 30%; moderate-quality evidence) or any of the other outcomes assessed (i.e. cardiac events (low-quality evidence), myocardial infarction, stroke, thromboembolism (all high-quality evidence)). High-quality evidence shows that the liberal transfusion threshold did not affect the risk of infection (pneumonia, wound infection, or bacteraemia). Transfusion-specific reactions are uncommon and were inconsistently reported within trials. We noted less certainty in the strength of evidence to support the safety of restrictive transfusion thresholds for the following predefined clinical subgroups: myocardial infarction, vascular surgery, haematological malignancies, and chronic bone-marrow disorders.

AUTHORS' CONCLUSIONS

Transfusion at a restrictive haemoglobin concentration decreased the proportion of people exposed to RBC transfusion by 41% across a broad range of clinical contexts. Across all trials, no evidence suggests that a restrictive transfusion strategy impacted 30-day mortality, mortality at other time points, or morbidity (i.e. cardiac events, myocardial infarction, stroke, pneumonia, thromboembolism, infection) compared with a liberal transfusion strategy. Despite including 17 more randomised trials (and 8846 participants), data remain insufficient to inform the safety of transfusion policies in important and selected clinical contexts, such as myocardial infarction, chronic cardiovascular disease, neurological injury or traumatic brain injury, stroke, thrombocytopenia, and cancer or haematological malignancies, including chronic bone marrow failure.  Further work is needed to improve our understanding of outcomes other than mortality. Most trials compared only two separate thresholds for haemoglobin concentration, which may not identify the actual optimal threshold for transfusion in a particular patient. Haemoglobin concentration may not be the most informative marker of the need for transfusion in individual patients with different degrees of physiological adaptation to anaemia. Notwithstanding these issues, overall findings provide good evidence that transfusions with allogeneic RBCs can be avoided in most patients with haemoglobin thresholds between the range of 7.0 g/dL and 8.0 g/dL. Some patient subgroups might benefit from RBCs to maintain higher haemoglobin concentrations; research efforts should focus on these clinical contexts.

The need to screen for anemia in exercising women

ABSTRACT

Anemia is common, affecting 1 in 3 women in their lifetime. Despite high prevalence rates, awareness is poor. This is relevant for women undertaking sport as anemia can lead to reduced physical performance. There is no current screening program for testing of anemia for exercising women. Therefore, the objective of the present study was to assess a simple screening tool to predict anemia in exercising women.Cross sectional survey study.National fitness festival.Three hundred exercising women.Screening methodology (Female Health Questionnaire and a haemoglobin concentration measurement).The Female Health Questionnaire inquired about; previous iron status, menstrual blood loss, diet, and motherhood. Participants were asked to self-report any symptoms of iron deficiency, including; brain fog, palpitations, shortness of breath, restless legs, hair loss, and pica. Results were compared to fingerprick haemoglobin levels with anemia defined as [Hb] < 120 g/L.Average age was 31.21years (s.d.7.72), average [Hb] was 131.76 g/L (s.d.11.5) and 36 (12%) had anemia. A history of iron deficiency was reported by 127 (43.49%), 127 (43.49%) reported heavy menstrual bleeding (HMB), 75 were vegetarian (18%) or vegan (8%) and 33 were mothers (11%). In total 80 reported taking time off work (total 1612 days). Women with anemia more commonly reported HMB (58.33% vs. 41.57%, P = .04), and those with HMB were more likely to report days off (39.37% vs. 18.18%, P < .001).Anemia was common in exercising women, particularly those with HMB. A simple screening tool for HMB and finger prick haemoglobin testing for anemia is recommended in women undertaking exercise.

Impact of gender parity on preoperative anaemia prevalence and Patient Blood Management practice

BACKGROUND

Anaemia is a common finding in the preoperative setting, affecting around one-third of patients for whom major surgery is programmed. Moreover, preoperative anaemia has been shown to worsen patient outcome and increase length of hospital stay and costs. In the field of preoperative anaemia correction, a recent Consensus statement suggested reviewing the classic World Health Organization (WHO) criteria in adults by aligning the haemoglobin cut-off to 13 g/dL for both genders. The aim of our study was to assess the differences in terms of prevalence, transfusion rate, transfusion trigger, and blood losses according to gender in a mixed population of surgical patients.

MATERIAL AND METHODS

We reviewed data of 610 consecutive patients undergoing elective major surgery at a tertiary care hospital during a 9-month period. Transfusion rate and transfusion triggers were recorded, analysed and stratified by haemoglobin class, with a particular focus on the 12.0-12.9 g/dL range.

RESULTS

Since the anaemia threshold was redefined at 13 g/dL for both genders, its prevalence rose from 26.4 to 39.5% (161/610 vs 241/610; p<0.001) in the overall population and from 22.7 to 49.3% (68/300 vs 148/300; p<0.001) in women. Eighty women (26.7%) fell in the haemoglobin 12.0-12.9 g/dL range, and this category was the most represented among transfused women (34.0%). There was no statistical difference in transfusion triggers or overall transfusion rate between genders. Subjects of both genders were transfused at the same haemoglobin level (8.1 g/dL), but women reached the transfusion trigger after less red cell mass loss than men, i.e. 377 mL (249-472 mL) vs 528 mL (356-717 mL), respectively (p<0.001).

DISCUSSION

Treatment of pre-surgical anaemia is one of the core principles of Patient Blood Management. Aligning the haemoglobin threshold between genders in the management of pre-surgical anaemia may result in a lower transfusion rate, but in an increased workload for medical staff in the preoperative phase.

Risk of venous thromboembolism in patients with elevated INR undergoing hepatectomy: an analysis of the American college of surgeons national surgical quality improvement program registry

BACKGROUND

Patients undergoing hepatectomy can have elevated INR and may have venous thromboembolism (VTE) prophylaxis withheld as a result. We sought to examine the association between preoperative INR elevation and VTE following hepatectomy.

METHODS

Hepatectomies captured in the American College of Surgeons National Surgical Quality Improvement Program registry between 2007 and 2016 were analyzed. Univariable and multivariable models examined the effect of incremental increases in preoperative INR on 30-day VTE, perioperative transfusion, serious morbidity, and mortality, adjusting for potential confounders.

RESULTS

We included 25,220 elective hepatectomies (62.4% partial lobectomies, 10.1% left hepatectomies, 18.6% right hepatectomies, 9.2% trisegmentectomies). The median age of the patients was 60 years and 49% were male. INR was elevated in 3089 patients (12.2%): 1.1-1.2 in 8.1%, 1.2-1.4 in 3.3%, and 1.4-2.0 in 0.9%. Incremental elevations in INR were independently associated with increasing risk for postoperative VTE [odds ratio (OR) 1.15, 95% confidence intervals 1.01-1.31], perioperative transfusion [OR 1.35 (1.28-1.43)], serious morbidity [OR 1.35 (1.28-1.43)], and mortality [OR 1.76 (1.56-1.98)].

CONCLUSION

Elevation in preoperative INR was counter-intuitively associated with increased risk of both VTE and perioperative transfusion following hepatectomy. The role of perioperative thromboprophylaxis warrants further investigation to determine optimal care in patients with elevated preoperative INR.

Iron deficiency anaemia in pregnancy: A contemporary review

Iron deficiency anaemia is a global health problem, which particularly affects pregnant women. Iron deficiency anaemia during pregnancy is associated with increased maternal and perinatal morbidity and mortality. Maternal iron deficiency may also be associated with neurocognitive deficits in infants. Iron requirements increase during pregnancy and are influenced by hepcidin, the master regulator of iron homeostasis. The enduring global burden of maternal anaemia suggests that currently employed iron supplementation strategies are suboptimal. Recent developments in our understanding of systemic and placental iron homeostasis may improve therapeutic effectiveness by altering the dose and frequency of oral iron. Intravenous iron appears to be a safe treatment to correct maternal anaemia rapidly but research on patient-centred outcomes and cost-effectiveness is needed. Future trials should be adequately powered to assess outcomes relevant to pregnant women.

Associations between preoperative anaemia and hospital costs following major abdominal surgery: cohort study

Background

Determining the cost-effectiveness and sustainability of patient blood management programmes relies on quantifying the economic burden of preoperative anaemia. This retrospective cohort study aimed to evaluate the hospital costs attributable to preoperative anaemia in patients undergoing major abdominal surgery.

Methods

Patients who underwent major abdominal surgery between 2010 and 2018 were included. The association between preoperative patient haemoglobin (Hb) concentration and hospital costs was evaluated by curve estimation based on the least-square method. The in-hospital cost of index admission was calculated using an activity-based costing methodology. Multivariable regression analysis and propensity score matching were used to estimate the effects of Hb concentration on variables related directly to hospital costs.

Results

A total of 1286 patients were included. The median overall cost was US $18 476 (i.q.r.13 784–27 880), and 568 patients (44.2 per cent) had a Hb level below 13.0 g/dl. Patients with a preoperative Hb level below 9.0 g/dl had total hospital costs that were 50.6 (95 per cent c.i. 14.1 to 98.9) per cent higher than those for patients with a preoperative Hb level of 9.0–13.0 g/dl (P < 0.001), 72.5 (30.6 to 128.0) per cent higher than costs for patients with a Hb concentration of 13.1–15.0 g/dl (P < 0.001), and 62.4 (21.8 to 116.7) per cent higher than those for patients with a Hb level greater than 15.0 g/dl (P < 0.001). Multivariable general linear modelling showed that packed red blood cell (PRBC) transfusions were a principal cost driver in patients with a Hb concentration below 9.0 g/dl.

Conclusion

Patients with the lowest Hb concentration incurred the highest hospital costs, which were strongly associated with increased PRBC transfusions. Costs and possible complications may be decreased by treating preoperative anaemia, particularly more severe anaemia.

The effect of iron deficiency and anaemia on women's health

Iron deficiency and anaemia are global health problems and major causes of morbidity in women. Current definitions of anaemia in women are historic and have been challenged by recent data from observational studies. Menstrual loss, abnormal uterine bleeding and pregnancy put women at risk of developing iron deficiency which can result in severe fatigue, reduced exercise capacity and poor work performance. Iron deficiency and anaemia during pregnancy are associated with adverse maternal and fetal outcomes, including neurocognitive deficits in children born to iron-deficient mothers. Both iron deficiency and anaemia are common in women undergoing surgery but their association with poor outcomes remains uncertain. The enduring burden of iron deficiency and anaemia in women suggests that current strategies for recognition, prevention and treatment are limited in their utility. Improvements in our understanding of iron homeostasis and the development of new iron preparations, which are better absorbed with fewer side-effects, may improve therapeutic effectiveness of oral iron. Intravenous iron is efficacious for correcting anaemia rapidly but high-quality data on patient-centred outcomes and cost-effectiveness are currently lacking. Many recommendations for the treatment of iron deficiency and anaemia in national guidelines are not supported by high-quality evidence. There is a need for robust epidemiological data and well-designed clinical trials. The latter will require collaborative working between researchers and patients to design studies in ways that incorporate patients' perspectives on the research process and target outcomes that matter to them.

The misogyny of iron deficiency

Anaemia is common, particularly in women and the commonest underlying cause, iron deficiency, is often overlooked. Anaemia is associated with increased morbidity and mortality in patients undergoing anaesthesia; however, women are defined as being anaemic at a lower haemoglobin level than men. In this narrative review, we present the history of iron deficiency anaemia and how women's health has often been overlooked. Iron deficiency was first described as 'chlorosis' and a cause of 'hysteria' in women and initial treatment was by iron filings in cold wine. We present data of population screening demonstrating how common iron deficiency is, affecting 12-18% of apparently 'fit and healthy' women, with the most common cause being heavy menstrual bleeding; both conditions being often unrecognised. We describe a range of symptoms reported by women, that vary from fatigue to brain fog, hair loss and eating ice. We also describe experiments exploring the physical impact of iron deficiency, showing that reduced exercise performance is related to iron deficiency independent of haemoglobin concentration, as well as the impact of iron supplementation in women improving oxygen consumption and fitness. Overall, we demonstrate the need to single out women and investigate iron deficiency rather than accept the dogma of normality and differential treatment; this is to say, the need to change the current standard of care for women undergoing anaesthesia.

Gestational anaemia and severe acute maternal morbidity: a population-based study

Anaemia is frequently diagnosed during pregnancy. However, there are few data regarding its incidence, and the association with severe maternal morbidity remains uncertain and potentially biased in high-resource countries. The purpose of this study was to explore the association between gestational anaemia and severe acute maternal morbidity during and after delivery. We performed a cohort-nested case-control analysis from the epidemiology of severe maternal mortality (EPIMOMS) prospective study conducted in six French regions (2012-2013, n = 182,309 deliveries). There were 1669 women with severe acute maternal morbidity during or after delivery, according to a standardised definition obtained by expert consensus. The control group were randomly selected among women without severe morbidity who delivered in the same health centres (n = 3234). We studied the association between gestational anaemia and severe acute maternal morbidity during or after delivery overall, by cause, and by mode of delivery, using multivariable logistic regression and multiple imputation. Gestational anaemia was significantly more frequent in women with severe acute maternal morbidity (25.3%) than in controls (16.3%), p < 0.001, and mostly mild in both groups. After adjustment for confounders, women with gestational anaemia were at increased risk of overall severe acute maternal morbidity during and after delivery (adjusted OR (95%CI) 1.8 (1.5-2.1)). This association was also found for severe postpartum haemorrhage (adjusted OR (95%CI) 1.7 (1.5-2.0)), even after omitting the transfusion criterion (adjusted OR (95%CI) 1.9 (1.6-2.3)), and for severe acute maternal morbidity secondary to causes other than haemorrhage or pregnancy-related hypertensive disorders (adjusted OR (95%CI) 2.7 (1.9-4.0)). These results highlight the importance of optimising the diagnosis and management of anaemia during pregnancy.

The association of pre-operative anaemia with morbidity and mortality after emergency laparotomy

Pre-operative anaemia is associated with poor outcomes after elective surgery but its relationship with outcomes after emergency surgery is unclear. We analysed National Emergency Laparotomy Audit data from 1 December 2013 to 30 November 2017, excluding laparotomy for haemorrhage. Anaemia was classified as 'mild' 129-110 g.l-1; 'moderate' 109-80 g.l-1; or 'severe' ≤ 79 g.l-1. The primary outcome was 90-day mortality. Secondary outcomes were 30-day mortality, return to theatre and postoperative hospital stay. The primary outcome was available for 86,763 patients, of whom 45,306 (52%) were anaemic. There were 12,667 (15%) deaths at 90 postoperative days and 9246 (11%) deaths at 30 postoperative days. Anaemia was associated with increased 90-day and 30-day mortality, odds ratio (95%CI): mild, 1.15 (1.09-1.21); moderate, 1.44 (1.36-1.52); and severe, 1.42 (1.24-1.63), p < 0.001 for all; mild, 1.07 (1.00-1.12), p = 0.030; moderate, 1.30 (1.21-1.38), p < 0.001; and severe, 1.22 (1.05-1.43), p = 0.010, respectively. All categories of anaemia were associated with prolonged hospital stay, adjusted coefficient (95%CI): mild, 1.31 (1.01-1.62); moderate, 3.41 (3.04-3.77); severe, 2.80 (1.83-3.77), p < 0.001 for all. Moderate and severe anaemia were associated with increased risk of return to the operating theatre, odds ratio (95%CI): moderate 1.13 (1.06-1.21), p < 0.001; and severe 1.23 (1.06-1.43), p = 0.006. Pre-operative anaemia is common in patients undergoing emergency laparotomy and is associated with increased postoperative mortality and morbidity.

Blood management in enhanced recovery after hip and knee replacement

Enhanced recovery in orthopedic surgery is a global patient management strategy to achieve early functional recovery. Blood management is central to rehabilitation protocols after hip or knee replacement. Coagulation physiology in hip and knee replacement is now well described, showing aggravation of bleeding by hyperfibrinolysis. The present study approaches blood management via 3 questions. 1/How to anticipate and prevent transfusion risk preoperatively? Screening for predictive factors can target the at-risk population, enabling a strategy of preoperative hemoglobin level optimization. 2/How to improve intraoperative hemostasis so as to minimize blood loss? Anti-fibrinolytic and topical hemostatic agents have proven efficacy. Tranexamic acid plays a central role. The impact of the usual surgical techniques, such as pneumatic tourniquet and postoperative drainage, on bleeding needs assessment. 3/How to manage postoperative anemia? Anemia without signs of general intolerance is frequent at discharge, but has been little studied. This raises the question of the medical interest of correcting postoperative anemia. LEVEL OF EVIDENCE: Expert opinion, V.

Intravenous iron therapy for non-anaemic, iron-deficient adults

BACKGROUND

Iron deficiency is one of the most common nutritional deficiencies, and has a number of physiological manifestations. Early, or non-anaemic iron deficiency can result in fatigue and diminished exercise capacity. Oral iron preparations have a high incidence of intolerable side effects, and are ineffective in certain forms of iron deficiency. Consequently, intravenous iron preparations are increasingly used in the treatment of non-anaemic iron deficiency. The newer, more stable iron preparations in particular purport to have a lower incidence of side effects, and are now used across a range of different patient populations.

OBJECTIVES

To assess the effects of intravenous iron therapy in the treatment of adults with non-anaemic iron deficiency.

SEARCH METHODS

On 18 October 2019 we electronically searched CENTRAL, MEDLINE, Embase, two further databases and two trials registries 2019. We handsearched the references of full-text extracted studies, and contacted relevant study authors for additional data.

SELECTION CRITERIA

We included randomised controlled trials that compared any intravenous iron preparation to placebo in adults. We excluded other forms of comparison such as oral iron versus placebo, intramuscular iron versus placebo, or intravenous iron studies where other iron preparations were used as the comparator. We also excluded studies involving erythropoietin therapy or obstetric populations.

DATA COLLECTION AND ANALYSIS

Two review authors screened references for eligibility, extracted data and assessed risk of bias. We resolved differences in opinion through discussion and consensus, and where necessary, involved a third review author to adjudicate disputes. We contacted study authors to request additional data where appropriate. The primary outcome measures were haemoglobin concentration at the end of follow-up, and quality-of-life scores at end of follow-up. Secondary outcome measures were serum ferritin, peak oxygen consumption (as measured by cardiopulmonary exercise testing), adverse effects (graded as mild to moderate and severe) and bacterial infection. We pooled data for continuous outcomes, which we then reported as mean differences (MDs) with 95% confidence intervals (CIs). We reported quality-of-life metrics as standardised mean difference (SMD), and then converted them back into a more familiar measure, the Piper Fatigue Scale. We analysed dichotomous outcomes as risk ratios (RRs). Given an expected degree of heterogeneity, we used a random-effects model for all outcomes. We performed the analysis with the software package Review Manager 5.

MAIN RESULTS

This review includes 11 studies with 1074 participants. Outcome metrics for which data were available (haemoglobin concentration, quality-of-life scores, serum ferritin, peak oxygen consumption and mild to moderate adverse effects) were similar across the included studies. The incidence of severe adverse events across all studies was zero. None of the studies measured bacterial infection as a specific outcome metric. Substantial heterogeneity influenced the results of the meta-analysis, arising from differing patient populations, definitions of iron deficiency, iron preparations and dosing regimens, and time to end of follow-up. Consequently, many outcomes are reported with small group sizes and wide confidence intervals, with a subsequent downgrading in the quality of evidence. The level of bias in many included studies was high, further reducing confidence in the robustness of the results. We found that intravenous iron therapy may lead to a small increase in haemoglobin concentration of limited clinical significance compared to placebo (MD 3.04 g/L, 95% CI 0.65 to 5.42; I2 = 42%; 8 studies, 548 participants; low-quality evidence). Quality-of-life scores (Piper Fatigue Scale MD 0.73, 95% CI 0.29 to 1.18; I2 = 0%; studies = 3) and peak oxygen consumption (MD 2.77 mL/kg/min, 95% CI -0.89 to 6.43; I2 = 36%; 2 studies, 32 participants) were associated with very low-quality evidence, and we remain uncertain about the role of intravenous iron for these metrics. We were unable to present pooled estimates for the outcomes of serum ferritin at the end of follow-up or mild to moderate adverse effects due to extreme statistical heterogeneity. Ultimately, despite the results of the meta-analysis, the low- or very low-quality evidence for all outcomes precludes any meaningful interpretation of results beyond suggesting that further research is needed. We performed a Trial Sequential Analysis for all major outcomes, none of which could be said to have reached a necessary effect size.

AUTHORS' CONCLUSIONS

Current evidence is insufficient to show benefit of intravenous iron preparations for the treatment of non-anaemic iron deficiency across a variety of patient populations, beyond stating that it may result in a small, clinically insignificant increase in haemoglobin concentration. However, the certainty for even this outcome remains limited. Robust data for the effectiveness of intravenous iron for non-anaemic iron deficiency is still lacking, and larger studies are required to assess the effect of this therapy on laboratory, patient-centric, and adverse-effect outcomes.

Preoperative anemia-screening clinics

Preoperative anemia is associated with increased postoperative morbidity and mortality and with increased risk of perioperative transfusion. It is an important and modifiable risk factor for surgical patients. For high-blood-loss surgery, preoperative anemia is defined as hemoglobin <13 g/dL for both male and female patients. Preoperative anemia is common, ranging from 25% to 40% in large observational studies. The most common treatable cause of preoperative anemia is iron-deficiency anemia; the initial laboratory tests should focus on making this diagnosis. Management of iron-deficiency anemia includes iron supplementation with IV iron therapy when oral iron is ineffective or not tolerated, there is severe anemia, and there is insufficient time to surgery (<4 weeks). In other situations, erythropoiesis-stimulating agents may be considered, particularly for those patients with multiple alloantibodies or religious objections to transfusion. To facilitate the diagnosis and management of preoperative anemia, establishment of preoperative anemia-screening clinics is essential. The goals of management of preoperative anemia are to treat anemia, reduce the need for transfusion, and improve patient outcomes.

Guidelines for Perioperative Care in Elective Colorectal Surgery: Enhanced Recovery After Surgery (ERAS®) Society Recommendations: 2018

BACKGROUND

This is the fourth updated Enhanced Recovery After Surgery (ERAS®) Society guideline presenting a consensus for optimal perioperative care in colorectal surgery and providing graded recommendations for each ERAS item within the ERAS® protocol.

METHODS

A wide database search on English literature publications was performed. Studies on each item within the protocol were selected with particular attention paid to meta-analyses, randomised controlled trials and large prospective cohorts and examined, reviewed and graded according to Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system.

RESULTS

All recommendations on ERAS® protocol items are based on best available evidence; good-quality trials; meta-analyses of good-quality trials; or large cohort studies. The level of evidence for the use of each item is presented accordingly.

CONCLUSIONS

The evidence base and recommendation for items within the multimodal perioperative care pathway are presented by the ERAS® Society in this comprehensive consensus review.

An international consensus statement on the management of postoperative anaemia after major surgical procedures

Despite numerous guidelines on the management of anaemia in surgical patients, there is no pragmatic guidance for the diagnosis and management of anaemia and iron deficiency in the postoperative period. A number of experienced researchers and clinicians took part in a two-day expert workshop and developed the following consensus statement. After presentation of our own research data and local policies and procedures, appropriate relevant literature was reviewed and discussed. We developed a series of best-practice and evidence-based statements to advise on patient care with respect to anaemia and iron deficiency in the postoperative period. These statements include: a diagnostic approach to iron deficiency and anaemia in surgical patients; identification of patients appropriate for treatment; and advice on practical management and follow-up that is easy to implement. Available data allow the fulfilment of the requirements of Pillar 1 of Patient Blood Management. We urge national and international research funding bodies to take note of these recommendations, particularly in terms of funding large-scale prospective, randomised clinical trials that can most effectively address the important clinical questions and this clearly unmet medical need.

Intravenous iron therapy for non‐anaemic iron deficient adults

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:

To assess the effects of intravenous iron supplementation in the treatment of non‐anaemic iron deficiency in adult patients.