Response of erythropoiesis and iron metabolism to recombinant human erythropoietin in intensive care unit patients

Anemia From Inflammation After Intracerebral Hemorrhage and Relationships With Outcome

BACKGROUND

Baseline anemia is associated with poor intracerebral hemorrhage (ICH) outcomes. However, underlying drivers for anemia and whether anemia development after ICH impacts clinical outcomes are unknown. We hypothesized that inflammation drives anemia development after ICH and assessed their relationship to outcomes.

METHODS AND RESULTS

Patients with serial hemoglobin and iron biomarker concentrations from the HIDEF (High-Dose Deferoxamine in Intracerebral Hemorrhage) trial were analyzed. Adjusted linear mixed models assessed laboratory changes over time. Of 42 patients, significant decrements in hemoglobin occurred with anemia increasing from 19% to 45% by day 5. Anemia of inflammation iron biomarker criteria was met in 88%. A separate cohort of 521 patients with ICH with more granular serial hemoglobin and long-term neurological outcome data was also investigated. Separate regression models assessed whether (1) systemic inflammatory response syndrome (SIRS) scores related to hemoglobin changes over time and (2) hemoglobin changes related to poor 90-day outcome. In this cohort, anemia prevalence increased from 30% to 71% within 2 days of admission yet persisted beyond this time. Elevated systemic inflammatory response syndrome was associated with greater hemoglobin decrements over time (adjusted parameter estimate: -0.27 [95% CI, -0.37 to -0.17]) and greater hemoglobin decrements were associated with poor outcomes (adjusted odds ratio per 1 g/dL increase, 0.76 [95% CI, 0.62-0.93]) independent to inflammation and ICH severity.

CONCLUSIONS

We identified novel findings that acute anemia development after ICH is common, rapid, and related to inflammation. Because anemia development is associated with poor outcomes, further work is required to clarify if anemia, or its underlying drivers, are modifiable treatment targets that can improve ICH outcomes.

REGISTRATION

https://www.clinicaltrials.gov Unique identifier: NCT01662895.

Iron Metabolism in the Recovery Phase of Critical Illness with a Focus on Sepsis

Iron is an essential nutrient for humans and microbes, such as bacteria. Iron deficiency commonly occurs in critically ill patients, but supplementary iron therapy is not considered during the acute phase of critical illness since it increases iron availability for invading microbes and oxidative stress. However, persistent iron deficiency in the recovery phase is harmful and has potential adverse outcomes such as cognitive dysfunction, fatigue, and cardiopulmonary dysfunction. Therefore, it is important to treat iron deficiency quickly and efficiently. This article reviews current knowledge about iron-related biomarkers in critical illness with a focus on patients with sepsis, and provides possible criteria to guide decision-making for iron supplementation in the recovery phase of those patients.

Impact of anemia requiring transfusion or erythropoiesis-stimulating agents on new-onset cardiovascular events and mortality after continuous renal replacement therapy

Anemia is common in critically ill patients undergoing continuous renal replacement therapy (CRRT). We investigated the impact of anemia requiring red blood cell (RBC) transfusion or erythropoiesis-stimulating agents (ESAs) on patient outcomes after hospital discharge in critically ill patients with acute kidney injury (AKI) requiring CRRT. In this retrospective cohort study using the Health Insurance Review and Assessment database of South Korea, 10,923 adult patients who received CRRT for 3 days or more between 2010 and 2019 and discharged alive were included. Anemia was defined as the need for RBC transfusion or ESAs. Outcomes included cardiovascular events (CVEs) and all-cause mortality after discharge. The anemia group showed a tendency to be older with more females and had more comorbidities compared to the control group. Anemia was not associated with an increased risk of CVEs (adjusted hazard ratio [aHR]: 1.05; 95% confidence interval [CI]: 0.85-1.29), but was associated with an increased risk of all-cause mortality (aHR: 1.41; 95% CI 1.30-1.53). For critically ill patients with AKI requiring CRRT, anemia, defined as requirement for RBC transfusion or ESAs, may increase the long-term risk of all-cause mortality.

Postoperative anemia in cardiac surgery patients: a narrative review

PURPOSE

Anemia reduces the blood's ability to carry and deliver oxygen. Following cardiac surgery, anemia is very common and affects up to 90% of patients. Nevertheless, there is a paucity of data examining the prognostic value of postoperative anemia. In this narrative review, we present findings from the relevant literature on postoperative anemia in cardiac surgery patients, focusing on the incidence, risk factors, and prognostic value of postoperative anemia. We also explore the potential utility of postoperative anemia as a therapeutic target to improve clinical outcomes.

SOURCE

We conducted a targeted search of MEDLINE, Embase, and the Cochrane Database of Systematic Reviews up to September 2022, using a combination of search terms including postoperative (post-operative), perioperative (peri-operative), anemia (anaemia), and cardiac surgery.

PRINCIPAL FINDINGS

The reported incidence of postoperative anemia varied from 29% to 94% across the studies, likely because of variations in patient inclusion criteria and classification of postoperative anemia. Nonetheless, the weight of the evidence suggests that postoperative anemia is common and is an independent risk factor for adverse postoperative outcomes such as acute kidney injury, stroke, mortality, and functional outcomes.

CONCLUSIONS

In cardiac surgery patients, postoperative anemia is a common and prognostically important risk factor for postoperative morbidity and mortality. Nevertheless, there is a lack of data on whether active management of postoperative anemia is feasible or effective in improving patient outcomes.

Efficacy and Safety of Intravenous Iron Therapy for Treating Anaemia in Critically ill Adults: A Rapid Systematic Review With Meta-Analysis

Our objective was to systematically evaluate the efficacy and safety of intravenous (IV) iron therapy for treating anaemia in critically ill adults (>16 years) admitted to intensive care or high dependency units. We excluded quasi-RCTs and other not truly randomised trials. We searched 7 electronic databases (including CENTRAL, MEDLINE, and Embase) using a pre-defined search strategy from inception to June 14, 2021. One reviewer screened, extracted, and analysed data, with verification by a second reviewer of all decisions. We used Cochrane risk of bias (ROB) 1 and GRADE to assess the certainty of the evidence. We reported 3 comparisons across 1198 patients, in 8 RCTs: (1) IV iron vs control (7 RCTs, 748 participants); our primary outcome (hemoglobin (Hb) concentration at 10 to 30 days) was reported in 7 of the 8 included trials. There was evidence of an effect (very-low certainty) in favour of IV iron over control in the main comparison only (6 RCTs, n = 528, mean difference (MD) 0.52g/dL [95%CI 0.23, 0.81], P = .0005). For the remaining outcomes there was no evidence of an effect in either direction (low certainty of evidence for Hb concentration at <10 days; very-low certainty of evidence for hospital duration, ICU duration, hospital readmission, infection, mortality; HRQoL outcomes were not GRADED). (2) IV iron + subcutaneous erythropoietin (EPO) vs control (2 RCTs, 104 participants); reported outcomes showed no evidence of effect in either direction, based on very-low certainty evidence (Hb concentration at 10-30 days, and <10 days, infection, mortality). (3) Hepcidin-guided treatment with IV iron or iron+ EPO vs standard care (1 RCT, 399 participants) reported evidence of an effect in favour of the intervention for 90-day mortality (low certainty of evidence), but no other group differences for the reported outcomes (low certainty evidence for Hb concentration at 10-30 days, hospital duration; HRQoL was not GRADED). The evidence across all comparisons was downgraded for high and unclear ROB for lack of blinding, incomplete outcome data, baseline imbalance, and imprecision around the estimate (wide CIs and small sample size). In conclusion, the current evidence continues to support further investigation into the role for iron therapy in increasing Hb in critically ill patients. Recent, small, trials have begun to focus on patient-centred outcomes but a large, well conducted, and adequately powered trial is needed to inform clinical practice.

Risk of Infection Associated With Administration of Intravenous Iron: A Systematic Review and Meta-analysis

Importance

Intravenous iron is recommended by many clinical guidelines based largely on its effectiveness in reducing anemia. However, the association with important safety outcomes, such as infection, remains uncertain.

Objective

To examine the risk of infection associated with intravenous iron compared with oral iron or no iron.

Data Sources

Medline, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) were searched for randomized clinical trials (RCTs) from 1966 to January 31, 2021. Ongoing trials were sought from ClinicalTrials.gov, CENTRAL, and the World Health Organization International Clinical Trials Search Registry Platform.

Study Selection

Pairs of reviewers identified RCTs that compared intravenous iron with oral iron or no iron across all patient populations, excluding healthy volunteers. Nonrandomized studies published since January 1, 2007, were also included. A total of 312 full-text articles were assessed for eligibility.

Data Extraction and Synthesis

Data extraction and risk of bias assessments were performed according to the Preferred Reporting Items of Systematic Reviews and Meta-analyses (PRISMA) and Cochrane recommendations, and the quality of evidence was assessed using the GRADE (Grades of Recommendation, Assessment, Development, and Evaluation) approach. Two reviewers extracted data independently. A random-effects model was used to synthesize data from RCTs. A narrative synthesis was performed to characterize the reporting of infection.

Main Outcomes and Measures

The primary outcome was risk of infection. Secondary outcomes included mortality, hospital length of stay, and changes in hemoglobin and red blood cell transfusion requirements. Measures of association were reported as risk ratios (RRs) or mean differences.

Results

A total of 154 RCTs (32 920 participants) were included in the main analysis. Intravenous iron was associated with an increased risk of infection when compared with oral iron or no iron (RR, 1.17; 95% CI, 1.04-1.31; I2 = 37%; moderate certainty of evidence). Intravenous iron also was associated with an increase in hemoglobin (mean difference, 0.57 g/dL; 95% CI, 0.50-0.64 g/dL; I2 = 94%) and a reduction in the risk of requiring a red blood cell transfusion (RR, 0.93; 95% CI, 0.76-0.89; I2 = 15%) when compared with oral iron or no iron. There was no evidence of an effect on mortality or hospital length of stay.

Conclusions and Relevance

In this large systematic review and meta-analysis, intravenous iron was associated with an increased risk of infection. Well-designed studies, using standardized definitions of infection, are required to understand the balance between this risk and the potential benefits.

Patient harm associated with serial phlebotomy and blood waste in the intensive care unit: A retrospective cohort study

Background

Intensive care unit (ICU) patients are at high risk of anemia, and phlebotomy is a potentially modifiable source of blood loss. Our objective was to quantify daily phlebotomy volume for ICU patients, including blood discarded as waste during vascular access, and evaluate the impact of phlebotomy volume on patient outcomes.

Methods

This was a retrospective observational cohort study between September 2014 and August 2015 at a tertiary care academic medical-surgical ICU. A prospective audit of phlebotomy practices in March 2018 was used to estimate blood waste during vascular access. Multivariable logistic regression was used to evaluate phlebotomy volume as a predictor of ICU nadir hemoglobin < 80 g/L, and red blood cell transfusion.

Results

There were 428 index ICU admissions, median age 64.4 yr, 41% female. Forty-four patients (10%) with major bleeding events were excluded. Mean bedside waste per blood draw (144 draws) was: 3.9 mL from arterial lines, 5.5 mL central venous lines, and 6.3 mL from peripherally inserted central catheters. Mean phlebotomy volume per patient day was 48.1 ± 22.2 mL; 33.1 ± 15.0 mL received by the lab and 15.0 ± 8.1 mL discarded as bedside waste. Multivariable regression, including age, sex, admission hemoglobin, sequential organ failure assessment score, and ICU length of stay, showed total daily phlebotomy volume was predictive of hemoglobin <80 g/L (p = 0.002), red blood cell transfusion (p<0.001), and inpatient mortality (p = 0.002). For every 5 mL increase in average daily phlebotomy the odds ratio for nadir hemoglobin <80 g/L was 1.18 (95% CI 1.07–1.31) and for red blood cell transfusion was 1.17 (95% CI 1.07–1.28).

Conclusion

A substantial portion of daily ICU phlebotomy is waste discarded during vascular access. Average ICU phlebotomy volume is independently associated with ICU acquired anemia and red blood cell transfusion which supports the need for phlebotomy stewardship programs.

Preemptive intravenous iron therapy versus autologous whole blood therapy for early postoperative hemoglobin level in patients undergoing bimaxillary orthognathic surgery: a prospective randomized noninferiority trial

BACKGROUND

Previous studies have reported the efficacy and safety of intravenous (IV) iron therapy during the perioperative period as an alternative and adjunct to allogeneic blood transfusion. Preemptive IV iron therapy provides noninferior hemoglobin levels on postoperative day (POD) 1 compared to autologous whole blood therapy (AWBT) in healthy patients who had undergone bimaxillary orthognathic surgery.

METHODS

This was a prospective, patient-randomized, noninferiority trial. After excluding 2 patients, 64 patients were divided into two groups: the IV iron therapy group (patients received IV iron infusion 4 weeks before surgery; n = 32) and the AWBT group (2 units of autologous whole blood were collected 4 and 2 weeks before surgery; n = 32). The primary outcome was hemoglobin level on POD 1 and the prespecified noninferiority limit was - 1 g/dL.

RESULTS

Baseline data were comparable, including hemoglobin and iron levels, between the two groups. Immediately before surgery, the levels of hemoglobin, iron, and ferritin were higher in the IV iron group than in the AWBT group. The mean treatment difference (iron group-whole blood group) in hemoglobin level on POD 1 between the two groups was 0.09 (95% CI = - 0.83 to 1.0). As the lower limit of the 95% CI (- 0.83) was higher than the prespecified noninferiority margin (δ = - 1), noninferiority was established. On POD 2, the hemoglobin level became lower in the iron group, which eventually led to greater requirement of allogeneic blood transfusion compared to the whole blood group. However, the iron group did not require allogeneic blood transfusion during or early after surgery, and the whole blood group showed continuously higher incidence of overt iron deficiency compared to the iron group.

CONCLUSION

As collection of autologous whole blood caused overt iron loss and anemia before surgery and intraoperative transfusion of whole blood was not able to prevent the occurrence of persistent iron deficiency after surgery, IV iron therapy was found to have potential benefits for iron homeostasis and subsequent erythropoiesis in healthy patients early after bimaxillary orthognathic surgery.

TRIAL REGISTRATION

Clinical Research Information Service, Republic of Korea, approval number: KCT0003680 on March 27, 2019. https://cris.nih.go.kr/cris/search/search_result_st01_kren.jsp?seq=15769&sLeft=2&ltype=my&rtype=my .

The Association Between Anemia of Chronic Inflammation and Alzheimer's Disease and Related Dementias

Background

Dementia is a spectrum of neurological diseases characterized by memory impairment and cognitive decline with the pathogenesis and effective management remaining elusive. Several studies have identified a correlation between anemia and Alzheimer's disease and related dementias (ADRD); however, anemia subtypes and association with ADRD have yet to be studied conclusively.

Objective

To study an association between ADRD and anemia of chronic inflammation.

Methods

We conducted a retrospective case-control study of the patients, diagnosed with ADRD at Brookdale Hospital. Pair-wise comparisons between means of controls and cases in terms of iron studies and laboratory results were performed using a Mann-Whitney U test. Pair-wise comparisons between anemia subgroups (moderate and severe) were performed using a Two Sample proportion Z-Test, where for each couple of normally distributed population.

Results

There was a total of 4,517 (1,274 ADRD group; 3,243 Control group) patients. There was significant difference in hemoglobin 10.15 versus 11.04 [p-value <0.001]. Iron studies showed a significant difference in ferritin 395±488.18 versus 263±1023.4 [p < 0.001], total iron binding capacity 225±84.08 versus 266±82.30 [p < 0.001] and serum iron level 64±39.34 versus 53±41.83 [p < 0.001]. Folic acid and vitamin B12 levels were normal in both groups. Severe and moderate anemia in the ADRD group were respectively 6.2% [95% CI: 4.2-8.4] and 13% [95% CI: 9.8-16.2] higher. Overall, incidence of moderate-to-severe anemia was found to be 19% higher in ADRD group [95% CI: 15.8-22.1].

Conclusion

We demonstrated an association between ADRD and anemia of chronic inflammation independent of age, renal function, and HgbA1C levels.

Management and prevention of anemia (acute bleeding excluded) in adult critical care patients

OBJECTIVE

Anemia is very common in critical care patients, on admission (affecting about two thirds of patients), but also during and after their stay, due to repeated blood loss, the effects of inflammation on erythropoiesis, a decreased red blood cell life span, and haemodilution. Anemia is associated with severity of illness and length of stay.

METHODS

A committee composed of 16 experts from four scientific societies, SFAR, SRLF, SFTS and SFVTT, evaluated three fields: (1) anaemia prevention, (2) transfusion strategies and (3) non-transfusion treatment of anaemia. Population, Intervention, Comparison, and Outcome (PICO) questions were reviewed and updated as needed, and evidence profiles were generated. Analysis of the literature and formulation of recommendations were then conducted according to the GRADE® methodology.

RESULTS

The SFAR-SRLF guideline panel provided ten statements concerning the management of anemia in adult critical care patients. Acute haemorrhage and chronic anemia were excluded from the scope of these recommendations. After two rounds of discussion and various amendments, a strong consensus was reached for ten recommendations. Three of these recommendations had a high level of evidence (GRADE 1±) and four had a low level of evidence (GRADE 2±). No GRADE recommendation could be provided for two questions in the absence of strong consensus.

CONCLUSIONS

The experts reached a substantial consensus for several strong recommendations for optimal patient management. The experts recommended phlebotomy reduction strategies, restrictive red blood cell transfusion and a single-unit transfusion policy, the use of red blood cells regardless of storage time, treatment of anemic patients with erythropoietin, especially after trauma, in the absence of contraindications and avoidance of iron therapy (except in the context of erythropoietin therapy).

Management and prevention of anemia (acute bleeding excluded) in adult critical care patients

Objective

Anemia is very common in critical care patients, on admission (affecting about two-thirds of patients), but also during and after their stay, due to repeated blood loss, the effects of inflammation on erythropoiesis, a decreased red blood cell life span, and haemodilution. Anemia is associated with severity of illness and length of stay.

Methods

A committee composed of 16 experts from four scientific societies, SFAR, SRLF, SFTS and SFVTT, evaluated three fields: (1) anemia prevention, (2) transfusion strategies and (3) non-transfusion treatment of anemia. Population, Intervention, Comparison, and Outcome (PICO) questions were reviewed and updated as needed, and evidence profiles were generated. Analysis of the literature and formulation of recommendations were then conducted according to the GRADE^® methodology.

Results

The SFAR–SRLF guideline panel provided ten statements concerning the management of anemia in adult critical care patients. Acute haemorrhage and chronic anemia were excluded from the scope of these recommendations. After two rounds of discussion and various amendments, a strong consensus was reached for ten recommendations. Three of these recommendations had a high level of evidence (GRADE 1±) and four had a low level of evidence (GRADE 2±). No GRADE recommendation could be provided for two questions in the absence of strong consensus.

Conclusions

The experts reached a substantial consensus for several strong recommendations for optimal patient management. The experts recommended phlebotomy reduction strategies, restrictive red blood cell transfusion and a single-unit transfusion policy, the use of red blood cells regardless of storage time, treatment of anaemic patients with erythropoietin, especially after trauma, in the absence of contraindications and avoidance of iron therapy (except in the context of erythropoietin therapy).

Persistent inflammation and anemia among critically ill septic patients

BACKGROUND

Associations among inflammatory cytokines, erythropoietin (EPO), and anemia in critically ill septic patients remain unclear. This study tested the hypothesis that elevated inflammatory cytokines and decreased EPO would be associated with iron-restricted anemia while accounting for operative blood loss, phlebotomy blood loss, and red blood cell (RBC) transfusion volume.

METHODS

Prospective observational cohort study of 42 critically ill septic patients was conducted. Hemoglobin (Hb) at sepsis onset and hospital discharge were used to calculate ΔHb. Operative blood loss, phlebotomy blood loss, and RBC transfusion volume were used to calculate adjusted ΔHb (AdjΔHb) assuming that 300 mL RBC is equal to 1 g/dL Hb. Patients with AdjΔHb of greater than 0 (positive AdjΔHb, n = 18) were compared with patients with AdjΔHb of less than or equal to 0 (negative AdjΔHb, n = 24).

RESULTS

Plasma tumor necrosis factor α, granulocyte colony-stimulating factor, interleukin (IL)-6, IL-8, EPO, erythrocyte mean corpuscular volume, and serum transferrin receptor were measured on days 0, 1, 4, 7, and 14. Patients with negative AdjΔHb had significantly higher day 14 levels of IL-6 (37.4 vs. 15.2 pg/mL, p < 0.05), IL-8 (39.1 vs. 18.2 pg/mL, p = 0.01), and granulocyte colony-stimulating factor (101.3 vs. 60.5 pg/mL, p = 0.01), but not EPO. On linear regression analysis, lower AdjΔHb was associated with higher day 14 levels of IL-6 (r = 0.22, p < 0.01), IL-8 (r = 0.10, p = 0.04), stromal cell-derived factor 1 (r = 0.14, p = 0.02), and tumor necrosis factor α (r = 0.13, p = 0.02), but not EPO. Patients with negative AdjΔHb had significantly lower mean corpuscular volume on days 4 (89.6 vs. 93.2 fL/cell, p = 0.04), 7 (92.3 vs. 94.9 fL/cell, p = 0.04), and 14 (92.1 vs. 96.0 fL/cell, p = 0.03) but similar serum transferrin receptor levels.

CONCLUSION

Persistent elevation of inflammatory cytokines was associated with iron-restricted anemia among critically ill septic patients, occurring in the absence of systemic iron deficiency, independent of endogenous EPO.

LEVEL OF EVIDENCE

Prognostic study, level II.

Transfusion strategies in non-bleeding critically ill adults: a clinical practice guideline from the European Society of Intensive Care Medicine

OBJECTIVE

To develop evidence-based clinical practice recommendations regarding transfusion practices in non-bleeding, critically ill adults.

DESIGN

A task force involving 13 international experts and three methodologists used the GRADE approach for guideline development.

METHODS

The task force identified four main topics: red blood cell transfusion thresholds, red blood cell transfusion avoidance strategies, platelet transfusion, and plasma transfusion. The panel developed structured guideline questions using population, intervention, comparison, and outcomes (PICO) format.

RESULTS

The task force generated 16 clinical practice recommendations (3 strong recommendations, 13 conditional recommendations), and identified five PICOs with insufficient evidence to make any recommendation.

CONCLUSIONS

This clinical practice guideline provides evidence-based recommendations and identifies areas where further research is needed regarding transfusion practices and transfusion avoidance in non-bleeding, critically ill adults.

Inflammatory anemia-associated parameters are related to 28-day mortality in patients with sepsis admitted to the ICU: a preliminary observational study

Background

Anemia is one of the most common complications of sepsis. Sepsis-related anemia is associated mainly with inflammation. We aimed to observe the changes in the inflammatory anemia-associated parameters of patients with sepsis in the early stage of intensive care unit (ICU) admission and to evaluate their association with 28-day mortality.

Methods

A total of 198 patients with sepsis were divided into survivor (n = 110) and non-survivor (n = 88) groups on the basis of 28-day survival. Healthy volunteers (n = 20) were enrolled as a control group. Plasma levels of iron, ferritin, erythropoietin (EPO), soluble transferrin receptor (sTfR), hepcidin, interleukin-6 (IL-6), hemoglobin and the red blood cell distribution width (RDW) were measured on days 1, 3 and 7 of ICU admission. Clinical data and laboratory findings were collected, and the Sequential Organ Failure Assessment (SOFA) score was calculated.

Results

Patients with sepsis showed significant decreases in hemoglobin, plasma iron and sTfR/log ferritin and significant increases in plasma EPO, sTfR, hepcidin, ferritin and IL-6 on days 1, 3 and 7 of ICU admission compared with healthy volunteers. Hemoglobin was correlated negatively with plasma IL-6 and hepcidin. In patients with sepsis, non-survivors had significantly lower plasma iron, EPO and sTfR/log ferritin, but higher plasma hepcidin, ferritin and IL-6 than survivors on days 1, 3 and 7 of ICU admission. Plasma EPO, hepcidin, ferritin, IL-6, sTfR/log ferritin, the RDW and SOFA score were associated significantly with 28-day mortality but to a varying extent. In particular, in predicting 28-day mortality, plasma hepcidin had an area under the receiver operating curve of 0.808 and 87.3% specificity, which was the highest among the inflammatory anemia-associated parameters tested.

Conclusions

Inflammatory anemia-associated parameters changed significantly in patients with sepsis in the first week of ICU admission. Plasma EPO, hepcidin, ferritin, IL-6, sTfR/log ferritin, the RDW and SOFA score were associated significantly with 28-day mortality. Plasma hepcidin might have a superior predictive value, with high specificity, compared with other inflammatory anemia-associated parameters for 28-day mortality of sepsis patients in the ICU.

Electronic supplementary material

The online version of this article (10.1186/s13613-019-0542-7) contains supplementary material, which is available to authorized users.

Recombinant Human Erythropoietin in Severe Anaemia: Issues of Dosing and Duration

The majority of Jehovah's Witnesses refuse blood product transfusion, even when it can be lifesaving. Treatment with recombinant human erythropoietin (RHuEPO) is a valuable adjunct in Jehovah's Witness patients undergoing surgery. A number of additional strategies, including acute normovolaemic haemodilution, intra-operative blood salvage and reinfusion, iron and folate supplementation are also utilized to avoid blood transfusion. Critically ill patients have blunted erythropoietin production and decreased endogenous iron availability. This case report reviews the treatment of anaemia in critically ill Jehovah's Witness patients after surgery and discusses the potential need for higher RHuEPO dosing strategies and longer duration of therapy.

Safety and efficacy of iron therapy on reducing red blood cell transfusion requirements and treating anaemia in critically ill adults: A systematic review with meta-analysis and trial sequential analysis

PURPOSE

To evaluate the safety (risk of infection) and efficacy (transfusion requirements, changes in haemoglobin (Hb)) of iron therapy in adult intensive care unit (ICU) patients.

MATERIALS AND METHODS

We systematically searched seven databases for all relevant studies until January 2018 and included randomized (RCT) studies comparing iron, by any route, with placebo/no iron.

RESULTS

805 participants from 6 RCTs were included. Iron therapy, by any route, did not decrease the risk of requirement for a red blood cell (RBC) transfusion (Risk ratio (RR) 0.91, 95% CI 0.80 to 1.04, p = 0.15) or mean number of RBCs transfused per participant (mean difference (MD) -0.30, 95% CI -0.68 to 0.07, p = 0.15). Iron therapy did increase mean Hb concentration (MD 0.31 g/dL, 95% CI 0.04 to 0.59, p = 0.03). There was no difference in infection (RR 0.95, 95% CI 0.79 to 1.19, p = 0.44). Trial Sequential Analysis suggests that the required participant numbers to detect or reject a clinically important effect of iron therapy on transfusion requirements or infection in ICU patients has not yet been reached.

CONCLUSION

Iron therapy results in a modest increase in Hb. The current evidence is inadequate to exclude an important effect on transfusion requirements or infection.

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.

Harms of off-label erythropoiesis-stimulating agents for critically ill people

BACKGROUND

Anaemia is a common problem experienced by critically-ill people. Treatment with erythropoiesis-stimulating agents (ESAs) has been used as a pharmacologic strategy when the blunted response of endogenous erythropoietin has been reported in critically-ill people. The use of ESAs becomes more important where adverse clinical outcomes of transfusing blood products is a limitation. However, this indication for ESAs is not licensed by regulatory authorities and is called off-label use. Recent studies concern the harm of ESAs in a critical care setting.

OBJECTIVES

To focus on harms in assessing the effects of erythropoiesis-stimulating agents (ESAs), alone or in combination, compared with placebo, no treatment or a different active treatment regimen when administered off-label to critically-ill people.

SEARCH METHODS

We conducted a systematic search of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, PsycINFO via OvidSP, CINAHL, all evidence-based medicine (EBM) reviews including IPA and SCI-Expanded, Conference Proceedings Citation Index- Science, BIOSIS Previews and TOXLINE up to February 2017. We also searched trials registries, checked reference lists of relevant studies and tracked their citations by using SciVerse Scopus.

SELECTION CRITERIA

We considered randomized controlled trials (RCTs) and controlled observational studies, which compared scheduled systemic administration of ESAs versus other effective interventions, placebo or no treatment in critically-ill people.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened and evaluated the eligibility of retrieved records, extracted data and assessed the risks of bias and quality of the included studies. We resolved differences in opinion by consensus or by involving a third review author. We assessed the evidence using GRADE and created a 'Summary of findings' table. We used fixed-effect or random-effects models, depending on the heterogeneity between studies. We fitted three-level hierarchical Bayesian models to calculate overall treatment effect estimates.

MAIN RESULTS

Of the 27,865 records identified, 39 clinical trials and 14 observational studies, including a total of 945,240 participants, were eligible for inclusion. Five studies are awaiting classification. Overall, we found 114 adverse events in 33 studies (30 RCTs and three observational studies), and mortality was reported in 41 studies (32 RCTs and nine observational studies). Most studies were at low to moderate risk of bias for harms outcomes. However, overall harm assessment and reporting were of moderate to low quality in the RCTs, and of low quality in the observational studies. We downgraded the GRADE quality of evidence for venous thromboembolism and mortality to very low and low, respectively, because of risk of bias, high inconsistency, imprecision and limitations of study design.It is unclear whether there is an increase in the risk of any adverse events (Bayesian risk ratio (RR) 1.05, 95% confidence interval (CI) 0.93 to 1.21; 3099 participants; 9 studies; low-quality evidence) or venous thromboembolism (Bayesian RR 1.04, 95% CI 0.70 to 1.41; 18,917 participants; 18 studies; very low-quality evidence).There was a decreased risk of mortality with off-label use of ESAs in critically-ill people (Bayesian RR 0.76, 95% CI 0.61 to 0.92; 930,470 participants; 34 studies; low-quality evidence).

AUTHORS' CONCLUSIONS

Low quality of evidence suggests that off-label use of ESAs may reduce mortality in a critical care setting. There was a lack of high-quality evidence about the harm of ESAs in critically-ill people. The information for biosimilar ESAs is less conclusive. Most studies neither evaluated ESAs' harm as a primary outcome nor predefined adverse events. Any further studies of ESA should address the quality of evaluating, recording and reporting of adverse events.

Characterization of erythropoietin and hepcidin in the regulation of persistent injury-associated anemia

BACKGROUND

The cause of persistent injury-associated anemia is multifactorial and includes acute blood loss, an altered erythropoietin (EPO) response, dysregulation of iron homeostasis, and impaired erythropoiesis in the setting of chronic inflammation/stress. Hepcidin plays a key role in iron homeostasis and is regulated by anemia and inflammation. Erythropoietin is a main regulator of erythropoiesis induced by hypoxia. A unique rodent model of combined lung injury (LC)/hemorrhagic shock (HS) (LCHS)/chronic restraint stress (CS) was used to produce persistent injury-associated anemia to further investigate the roles of EPO, hepcidin, iron, ferritin, and the expression of EPO receptors (EPOr).

METHODS

Male Sprague-Dawley rats were randomly assigned into one of the four groups of rodent models: naive, CS alone, combined LCHS, or LCHS/CS. Plasma was used to evaluate levels of EPO, hepcidin, iron, and ferritin. RNA was isolated from bone marrow and lung tissue to evaluate expression of EPOr. Comparisons between models were performed by t tests followed by one-way analysis of variance.

RESULTS

After 7 days, only LCHS/CS was associated with persistent anemia despite significant elevation of plasma EPO. Combined LCHS and LCHS/CS led to a persistent decrease in EPOr expression in bone marrow on Day 7. The LCHS/CS significantly decreased plasma hepcidin levels by 75% on Day 1 and 84% on Day 7 compared to LCHS alone. Hepcidin plasma levels are inversely proportional to EPO plasma levels (Pearson R = -0.362, p < 0.05).

CONCLUSION

Tissue injury, hemorrhagic shock, and stress stimulate and maintain high levels of plasma EPO while hepcidin levels are decreased. In addition, bone marrow EPOr and plasma iron availability are significantly reduced following LCHS/CS. The combined deficit of reduced iron availability and reduced bone marrow EPOr expression may play a key role in the ineffective EPO response associated with persistent injury-associated anemia.

Effects of short-term hyperoxia on erythropoietin levels and microcirculation in critically Ill patients: a prospective observational pilot study

BACKGROUND

The normobaric oxygen paradox states that a short exposure to normobaric hyperoxia followed by rapid return to normoxia creates a condition of 'relative hypoxia' which stimulates erythropoietin (EPO) production. Alterations in glutathione and reactive oxygen species (ROS) may be involved in this process. We tested the effects of short-term hyperoxia on EPO levels and the microcirculation in critically ill patients.

METHODS

In this prospective, observational study, 20 hemodynamically stable, mechanically ventilated patients with inspired oxygen concentration (FiO2) ≤0.5 and PaO2/FiO2 ≥ 200 mmHg underwent a 2-hour exposure to hyperoxia (FiO2 1.0). A further 20 patients acted as controls. Serum EPO was measured at baseline, 24 h and 48 h. Serum glutathione (antioxidant) and ROS levels were assessed at baseline (t0), after 2 h of hyperoxia (t1) and 2 h after returning to their baseline FiO2 (t2). The microvascular response to hyperoxia was assessed using sublingual sidestream dark field videomicroscopy and thenar near-infrared spectroscopy with a vascular occlusion test.

RESULTS

EPO increased within 48 h in patients exposed to hyperoxia from 16.1 [7.4-20.2] to 22.9 [14.1-37.2] IU/L (p = 0.022). Serum ROS transiently increased at t1, and glutathione increased at t2. Early reductions in microvascular density and perfusion were seen during hyperoxia (perfused small vessel density: 85% [95% confidence interval 79-90] of baseline). The response after 2 h of hyperoxia exposure was heterogeneous. Microvascular perfusion/density normalized upon returning to baseline FiO2.

CONCLUSIONS

A two-hour exposure to hyperoxia in critically ill patients was associated with a slight increase in EPO levels within 48 h. Adequately controlled studies are needed to confirm the effect of short-term hyperoxia on erythropoiesis.

TRIAL REGISTRATION

ClinicalTrials.gov ( www.clinicaltrials.gov ), NCT02481843 , registered 15th June 2015, retrospectively registered.

Anemia of Inflammation: A Review

Impaired iron homeostasis and the suppressive effects of proinflammatory cytokines on erythropoiesis, together with alterations of the erythrocyte membrane that impair its survival, cause anemia of inflammation. Recent epidemiologic studies have connected inflammatory anemia with critical illness, obesity, aging, kidney failure, cancer, chronic infection, and autoimmune disease. The proinflammatory cytokine, interleukin-6, the iron regulatory hormone, hepcidin, and the iron exporter, ferroportin, interact to cause iron sequestration in the setting of inflammation. Although severe anemia is associated with adverse outcomes in critical illness, experimental models suggest that iron sequestration is part of a natural defense against pathogens.

Iron supplementation to treat anaemia in adult critical care patients: a systematic review and meta-analysis

BACKGROUND

Anaemia affects 60-80 % of patients admitted to intensive care units (ICUs). Allogeneic red blood cell (RBC) transfusions remain the mainstay of treatment for anaemia but are associated with risks and are costly. Our objective was to assess the efficacy and safety of iron supplementation by any route, in anaemic patients in adult ICUs.

METHODS

Electronic databases (CENTRAL, MEDLINE, EMBASE) were searched through March 2016 for randomized controlled trials (RCT)s comparing iron by any route with placebo/no iron. Primary outcomes were red blood cell transfusions and mean haemoglobin concentration. Secondary outcomes included mortality, infection, ICU and hospital length of stay, mean difference (MD) in iron biomarkers, health-related quality of life and adverse events.

RESULTS

Five RCTs recruiting 665 patients met the inclusion criteria; intravenous iron was tested in four of the RCTs. There was no difference in allogeneic RBC transfusion requirements (relative risk 0.87, 95 % confidence interval (CI) 0.70 to 1.07, p = 0.18, five trials) or mean number of RBC units transfused (MD -0.45, 95 % CI -1.34 to 0.43, p = 0.32, two trials) in patients receiving or not receiving iron. Similarly, there was no difference between groups in haemoglobin at short-term (up to 10 days) (MD -0.25, 95 % CI -0.79 to 0.28, p = 0.35, three trials) or mid-term follow up (last measured time point in hospital or end of trial) (MD 0.21, 95 % CI -0.13 to 0.55, p = 0.23, three trials). There was no difference in secondary outcomes of mortality, in-hospital infection, or length of stay. Risk of bias was generally low although three trials had high risk of attrition bias; only one trial had low risk of bias across all domains.

CONCLUSION

Iron supplementation does not reduce RBC transfusion requirements in critically ill adults, but there is considerable heterogeneity between trials in study design, nature of interventions, and outcomes. Well-designed trials are needed to investigate the optimal iron dosing regimens and strategies to identify which patients are most likely to benefit from iron, together with patient-focused outcomes.

TRIAL REGISTRATION

PROSPERO International prospective register of systematic reviews CRD42015016627 . Registered 2 March 2015.

[Hospital-acquired anemia: Facts, consequences and prevention]

Hospital-acquired anemia is common, especially in the most critically ill patients. It may be associated with poor patient outcomes. It may result from increased blood loss, impaired red cell production or reduced red cell life span. Multiple associated factors may contribute simultaneously or sequentially to the decrease in hemoglobin level. Some of them are related to the underlying disease and others are iatrogenic. Clinicians should be aware of the importance and consequences of iatrogenic anemia caused by diagnostic blood sampling. Strategies and measures to minimize iatrogenic blood loss should be prioritized. They may reduce the risk of developing anemia and then red blood cells transfusion requirement.

Understanding anemia of chronic disease

The anemia of chronic disease is an old disease concept, but contemporary research in the role of proinflammatory cytokines and iron biology has shed new light on the pathophysiology of the condition. Recent epidemiologic studies have connected the anemia of chronic disease with critical illness, obesity, aging, and kidney failure, as well as with the well-established associations of cancer, chronic infection, and autoimmune disease. Functional iron deficiency, mediated principally by the interaction of interleukin-6, the iron regulatory hormone hepcidin, and the iron exporter ferroportin, is a major contributor to the anemia of chronic disease. Although anemia is associated with adverse outcomes, experimental models suggest that iron sequestration is desirable in the setting of severe infection. Experimental therapeutic approaches targeting interleukin-6 or the ferroportin–hepcidin axis have shown efficacy in reversing anemia in either animal models or human patients, although these agents have not yet been approved for the treatment of the anemia of chronic disease.

Beyond soluble transferrin receptor: old challenges and new horizons

Disturbances of iron metabolism are a frequent challenge in outpatient and inpatient care. Although several established biomarkers are commonly used by clinicians for differential diagnosis, the discrimination between latent or classic iron deficiency, anaemia of chronic disease or a combination of functional iron deficiency (iron-restricted erythropoiesis) with anaemia of chronic disease in patients affected by inflammatory disease can be demanding. Soluble transferrin receptor (sTfR) is a cleaved monomer of transferrin receptor 1 and correlates positively with tissue iron deficiency as well as with stimulated erythropoiesis. The ratio between sTfR and ferritin in combination with reticulocyte haemoglobin content further helps to identify different states of iron deficiency. In this review, we will focus on biological aspects of iron metabolism and sTfR, established clinical applications and limitations of sTfR and derived indices, and prospects of future research and applications.

Ceruloplasmin and Hypoferremia: Studies in Burn and Non-Burn Trauma Patients

OBJECTIVE

Normal iron handling appears to be disrupted in critically ill patients leading to hypoferremia that may contribute to systemic inflammation. Ceruloplasmin (Cp), an acute phase reactant protein that can convert ferrous iron to its less reactive ferric form facilitating binding to ferritin, has ferroxidase activity that is important to iron handling. Genetic absence of Cp decreases iron export resulting in iron accumulation in many organs. The objective of this study was to characterize iron metabolism and Cp activity in burn and non-burn trauma patients to determine if changes in Cp activity are a potential contributor to the observed hypoferremia.

MATERIAL AND METHODS

Under Brooke Army Medical Center Institutional Review Board approved protocols, serum or plasma was collected from burn and non-burn trauma patients on admission to the ICU and at times up to 14 days and measured for indices of iron status, Cp protein and oxidase activity and cytokines.

RESULTS

Burn patients showed evidence of anemia and normal or elevated ferritin levels. Plasma Cp oxidase activity in burn and trauma patients were markedly lower than controls on admission and increased to control levels by day 3, particularly in burn patients. Plasma cytokines were elevated throughout the 14 days study along with evidence of an oxidative stress. No significant differences in soluble transferrin receptor were noted among groups on admission, but levels in burn patients were lower than controls for the first 5 days after injury.

CONCLUSION

This study further established the hypoferremia and inflammation associated with burns and trauma. To our knowledge, this is the first study to show an early decrease in Cp oxidase activity in burn and non-burn trauma patients. The results support the hypothesis that transient loss of Cp activity contributes to hypoferremia and inflammation. Further studies are warranted to determine if decreased Cp activity increases the risk of iron-induced injury following therapeutic interventions such as transfusions with blood that has undergone prolonged storage in trauma resuscitation.

Transfusion-free management of gastrointestinal bleeding: the experience of a bloodless institute

GOALS

The Institute for Patient Blood Management and Bloodless Medicine at the Englewood Hospital has considerable experience in managing patients with gastrointestinal bleeding who do not accept blood-derived products. We present our data and experience over the last 8 years in managing such patients.

BACKGROUND

There is paucity of data on management and outcomes of gastrointestinal bleeding in patients who do not accept blood-derived products.

STUDY

We performed a retrospective study of patients from 2003 to 2011 presenting with gastrointestinal bleeding who do not accept blood-derived products. Inclusion criteria were either overt bleeding with a presenting hemoglobin (Hb) of <12 g/dL or a decrease in Hb of >1.5 g/dL.

RESULTS

Ninety-six patients who met the inclusion criteria were included. Forty-one upper and 48 lower gastrointestinal bleeding sources were identified. Mean Hb was 8.8 g/dL and mean nadir was 6.9 g/dL. Among 37 patients (80.5%) with Hb ≤6.0 g/dL, 30 (81%) survived. Four of 7 patients (57%) with a Hb <3 g/dL survived. The overall mortality rate was 10.4%. In unadjusted logistic regression models, age [1.06 (1.01-1.12 y)], admission to ICU [6.37(1.27-31.9)], and anticoagulation use [6.95 (1.57-30.6)] were associated with increased mortality. Initial Hb [0.68 (0.51-0.92)] and nadir Hb [0.48 (0.29-0.78)] inversely predicted mortality.

CONCLUSIONS

These results suggest that transfusion-free management of gastrointestinal hemorrhage can be effective with mortality comparable with the general population accepting medically indicated transfusion. Management of these patients is challenging and requires a dedicated multidisciplinary team approach knowledgeable in techniques of blood conservation.

The safety of intravenous iron preparations: systematic review and meta-analysis

OBJECTIVE

To amass all available evidence regarding the safety of intravenous (IV) iron preparations to provide a true balance of efficacy and safety.

METHODS

Systematic review and meta-analysis of all randomized clinical trials comparing IV iron to another comparator. All electronic databases until January 1, 2014, were reviewed. Primary outcome was occurrence of severe adverse events (SAEs). Secondary outcomes included all-cause mortality and other adverse events (AEs). Subgroup analysis was performed on the basis of type of IV iron, comparator, treated condition, and system involved.

RESULTS

A total of 103 trials published between 1965 through 2013 were included. A total of 10,390 patients were treated with IV iron compared with 4044 patients treated with oral iron, 1329 with no iron, 3335 with placebo, and 155 with intramuscular iron. There was no increased risk of SAEs with IV iron (relative risk [RR], 1.04; 95% CI, 0.93-1.17; I(2)=9%). Subgroup analysis revealed a decreased rate of SAEs when IV iron was used to treat heart failure (RR, 0.45; 95% CI, 0.29-0.70; I(2)=0%). Severe infusion reactions were more common with IV iron (RR, 2.47; 95% CI, 1.43-4.28; I(2)=0%). There was no increased risk of infections with IV iron. Gastrointestinal AEs were reduced with IV iron.

CONCLUSION

Intravenous iron therapy is not associated with an increased risk of SAEs or infections. Infusion reactions are more pronounced with IV iron.

A multicenter, randomized clinical trial of IV iron supplementation for anemia of traumatic critical illness*

OBJECTIVE

To evaluate the efficacy of IV iron supplementation of anemic, critically ill trauma patients.

DESIGN

Multicenter, randomized, single-blind, placebo-controlled trial.

SETTING

Four trauma ICUs.

PATIENTS

Anemic (hemoglobin < 12 g/dL) trauma patients enrolled within 72 hours of ICU admission and with an expected ICU length of stay of more than or equal to 5 days.

INTERVENTIONS

Randomization to iron sucrose 100 mg IV or placebo thrice weekly for up to 2 weeks.

MEASUREMENTS AND MAIN RESULTS

A total of 150 patients were enrolled. Baseline iron markers were consistent with functional iron deficiency: 134 patients (89.3%) were hypoferremic, 51 (34.0%) were hyperferritinemic, and 64 (42.7%) demonstrated iron-deficient erythropoiesis as evidenced by an elevated erythrocyte zinc protoporphyrin concentration. The median baseline transferrin saturation was 8% (range, 2-58%). In the subgroup of patients who received all six doses of study drug (n = 57), the serum ferritin concentration increased significantly for the iron as compared with placebo group on both day 7 (808.0 ng/mL vs 457.0 ng/mL, respectively, p < 0.01) and day 14 (1,046.0 ng/mL vs 551.5 ng/mL, respectively, p < 0.01). There was no significant difference between groups in transferrin saturation, erythrocyte zinc protoporphyrin concentration, hemoglobin concentration, or packed RBC transfusion requirement. There was no significant difference between groups in the risk of infection, length of stay, or mortality.

CONCLUSIONS

Iron supplementation increased the serum ferritin concentration significantly, but it had no discernible effect on transferrin saturation, iron-deficient erythropoiesis, hemoglobin concentration, or packed RBC transfusion requirement. Based on these data, routine IV iron supplementation of anemic, critically ill trauma patients cannot be recommended (NCT 01180894).

Prevalence of iron deficiency on ICU discharge and its relation with fatigue: a multicenter prospective study

INTRODUCTION

Prevalence of iron deficiency (ID) at intensive care (ICU) admission is around 25 to 40%. Blood losses are important during ICU stay, leading to iron losses, but prevalence of ID at ICU discharge is unknown. ID has been associated with fatigue and muscular weakness, and may thus impair post-ICU rehabilitation. This study assessed ID prevalence at ICU discharge, day 28 (D28) and six months (M6) after and its relation with fatigue.

METHODS

We conducted this prospective, multicenter observational study at four University hospitals ICUs. Anemic (hemoglobin (Hb) less than 13 g/dL in male and less than 12 g/dL in female) critically ill adult patients hospitalized for at least five days had an iron profile taken at discharge, D28 and M6. ID was defined as ferritin less than 100 ng/L or less than 300 ng/L together with a transferrin saturation less than 20%. Fatigue was assessed by numerical scale and the Multidimensional Fatigue Inventory-20 questionnaire at D28 and M6 and muscular weakness by a hand grip test at ICU discharge.

RESULTS

Among 107 patients (men 77%, median (IQR) age 63 (48 to 73) years) who had a complete iron profile at ICU discharge, 9 (8.4%) had ID. At ICU discharge, their hemoglobin concentration (9.5 (87.7 to 10.3) versus 10.2 (92.2 to 11.7) g/dL, P =0.09), hand grip strength (52.5 (30 to 65) versus 49.5 (15.5 to 67.7)% of normal value, P =0.61) and visual analog scale fatigue scale (57 (40 to 80) versus 60 (47.5 to 80)/100, P =0.82) were not different from non-ID patients. At D28 (n =80 patients) and M6 (n =78 patients), ID prevalence increased (to 25 and 35% respectively) while anemia prevalence decreased (from 100% to 80 and 25% respectively, P <0.0001). ID was associated with increased fatigue at D28, after adjustment for main confounding factors, including anemia (regression coefficient (95%CI), 3.19 (0.74 to 5.64), P =0.012). At M6, this association disappeared.

CONCLUSIONS

The prevalence of ID increases from 8% at discharge to 35% six months after prolonged ICU stay (more than five days). ID was associated with increased fatigue, independently of anemia, at D28.

Surgical management in treatment of Jehovah's witness in trauma surgery in Indian subcontinent

The Jehovah's Witness religion is a Christian movement, founded in the US in the 1870s, with 7 million followers worldwide with only 0.002% in India. There is minimal to complete absence of awareness about the existence of this community in our society. Astonishing is that fact that among medical professionals, there is almost no awareness about this unique population, regarding the fact that they completely refuse of blood transfusion even if it leads to their death. This is integral to their faith. Besides legal and ethical issues in treating these group of patients, the biggest challenge exist even in the western world is their management in trauma scenario where few options exist. We have discussed the issues and recommendations in management in trauma scenario in our Indian subcontinent.

Anaemia secondary to critical illness: an unexplained phenomenon

Almost all patients suffering critical illness become anaemic during their time in intensive care. The cause of this anaemia and its management has been a topic of debate in critical care medicine for the last two decades. Packed red cell transfusion has an associated cost and morbidity such that decreasing the number of units transfused would be of great benefit. Our understanding of the aetiology and importance of this anaemia is improving with recent and ongoing work to establish the cause, effect and best treatment options. This review aims to describe the current literature whilst suggesting that the nature of the anaemia should be considered with reference to the time point in critical illness. Finally, we suggest that using haemoglobin concentration as a measure of oxygen-carrying capacity has limitations and that ways of measuring haemoglobin mass should be explored.

Pathophysiology of perioperative anaemia

Perioperative anaemia is a common clinical entity. It is usually due to combination of various mechanisms, including: pre-existing anaemia prior to surgery; anaemia due to impaired erythropoiesis, including alterations of metabolism of iron and erythropoietin (EPO); anaemia due to increased destruction of red blood cells (RBCs); and anaemia due to iatrogenic causes. Postoperatively, anaemia resembles anaemia of chronic disease and is probably related to the effects of inflammatory mediators released during and after surgery on the production and survival of RBCs. Pro-inflammatory cytokines, such as tumour necrosis factor, impair erythropoietin-dependent signalling and iron homeostasis. Iatrogenic causes, notably excessive phlebotomies, remain a major cause of perioperative anaemia. With increasing emphasis on restrictive blood transfusion strategies, understanding these mechanisms is important for the clinician.

Impact of erythropoietin on intensive care unit patients

Anemia is common in intensive care unit (ICU) patients. Red blood cell (RBC) transfusions are mainstays of their treatment and can be life-saving. Allogeneic blood components inherently bear risks of infection and immune reactions. Although these risks are rare in developed countries, recombinant human erythropoietin (rhEpo) and other erythropoiesis-stimulating agents (ESAs) have been considered alternative anti-anemia treatment options. As summarized herein, however, most of the clinical studies suggest that ESAs are not usually advisable in ICU patients unless approved indications exist (e.g., renal disease). First, ESAs act in a delayed way, inducing an increase in reticulocytes only after a lag of 3-4 days. Second, many critically ill patients present with ESA resistance as inflammatory mediators impair erythropoietic cell proliferation and iron availability. Third, the ESA doses used for treatment of ICU patients are very high. Fourth, ESAs are not legally approved for general use in ICU patients. Solely in distinct cases, such as Jehovah's Witnesses who refuse allogeneic blood transfusions due to religious beliefs, ESAs may be considered an exceptional therapy.

Safety and efficacy of intravenous iron therapy in reducing requirement for allogeneic blood transfusion: systematic review and meta-analysis of randomised clinical trials

OBJECTIVES

To evaluate the efficacy and safety of intravenous iron, focusing primarily on its effects on haemoglobin, requirement for transfusion, and risk of infection.

DESIGN

Systematic review and meta-analysis of randomised controlled trials investigating the safety and efficacy of intravenous iron therapy.

DATA SOURCES

Randomised controlled trials from Medline, Embase, and the Cochrane Central Register of Controlled Trials from 1966 to June 2013, with no language restrictions.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Eligible trials were randomised controlled trials of intravenous iron compared with either no iron or oral iron. Crossover and observational studies were excluded.

MAIN OUTCOME MEASURES

Change in haemoglobin concentration and risk of allogeneic red blood cell transfusion (efficacy) and risk of infection (safety).

RESULTS

Of the 75 trials meeting the inclusion criteria, 72 studies including 10 605 patients provided quantitative outcome data for meta-analysis. Intravenous iron was associated with an increase in haemoglobin concentration (standardised mean difference 6.5 g/L, 95% confidence interval 5.1 g/L to 7.9 g/L) and a reduced risk of requirement for red blood cell transfusion (risk ratio 0.74, 95% confidence interval 0.62 to 0.88), especially when intravenous iron was used with erythroid stimulating agents (ESAs) or in patients with a lower baseline plasma ferritin concentration. There were no significant interactions between the efficacy of intravenous iron and type or dose administered. Intravenous iron was, however, associated with a significant increase in risk of infection (relative risk 1.33, 95% confidence interval 1.10 to 1.64) compared with oral or no iron supplementation. The results remained similar when only high quality trials were analysed.

CONCLUSIONS

Intravenous iron therapy is effective in increasing haemoglobin concentration and reducing the risk of allogeneic red blood cell transfusion and could have broad applicability to a range of acute care settings. This potential benefit is counterbalanced by a potential increased risk of infection.

Safety of off-label erythropoiesis stimulating agents in critically ill patients: a meta-analysis

PURPOSE

Erythropoiesis stimulating agents (ESAs) are used to treat anemia in critically ill patients. This indication is off-label, because it is not licensed by regulatory authorities. Recently ESAs were suspected to harm critically ill patients. Our objective was to assess the safety of ESAs in off-label indications in critically ill patients.

METHODS

Eleven databases were searched up to April 2012. We considered randomized controlled trials (RCTs) and controlled observational studies in any language that compared off-label ESAs treatment with other effective interventions, placebo or no treatment in critically ill patients. Two authors independently screened and evaluated retrieved records, extracted data and assessed risk of bias and quality of reporting.

RESULTS

We used frequentist and Bayesian models to combine studies, and performed sensitivity and subgroup analyses. From 12,888 citations, we included 48 studies (34 RCTs; 14 observational), involving 944,856 participants. Harm reporting was of medium to low quality. There was no statistically significant increased risk of adverse events in general, serious adverse events, the most frequently reported adverse events, and death in critically ill patients treated with ESAs. These results were robust against risk of bias and analysis methods. There is evidence that ESAs increase the risk of clinically relevant thrombotic vascular events, and there is some less certain evidence that ESAs might increase the risk for venous thromboembolism.

CONCLUSIONS

In critically ill patients, administration of ESAs is associated with a significant increase in clinically relevant thrombotic vascular events but not with other frequently reported adverse events and death.

The impact of anemia in moderate to severe traumatic brain injury

PURPOSE

The impact of anemia and restrictive transfusion strategies in traumatic brain injury (TBI) is unclear. The purpose of this study was to examine the outcome of varying degrees of anemia in patients who have sustained a TBI.

METHODS

We performed a retrospective study of all adult patients with isolated blunt TBI admitted between January 2003 and June 2010. The impact of increasing severity of anemia (Hb ≤8, ≤9, or ≤10 g/dl measured on three consecutive draws within the first 7 days of admission) and transfusions on complications, length of stay, and mortality was examined using univariate and multivariate analysis.

RESULTS

Of the 31,648 patients with blunt trauma admitted to the trauma service during the study period, 812 had an isolated TBI, among which 196 (24.1 %) met at least one of the anemia thresholds within the first 7 days [78 % male, mean age 47 ± 23 years, Injury Severity Score 16 ± 8, and head Abbreviated Injury Scale 3.3 ± 1.0]. Using a logistic regression model, anemia even as low as 8 g/dl was not associated with an increase in mortality [AOR8 = 0.8 (0.2, 3.2), p = 0.771; AOR9 = 0.8 (0.4, 1.6), p = 0.531; AOR10 = 0.6 (0.3, 1.3), p = 0.233] or complications. However, for all patients, the transfusion of packed red blood cells was associated with a significant increase in septic complications [AOR = 3.2 (1.5, 13.7), p = 0.030].

CONCLUSION

The presence of anemia in patients with TBI as low as 8 g/dl was not associated with increased mortality or complications, while the transfusion of red blood cells was associated with a significant increase in septic complications. Prospective evaluation of an optimal transfusion trigger in head-injured patients is warranted.

Blood conservation devices in critical care: a narrative review

Anaemia is associated with inferior outcomes in critically ill patients. It is difficult to prevent and is treated commonly with the transfusion of packed red cells. However, transfusion to augment oxygen delivery has not been shown to consistently offer a survival advantage when the haemoglobin concentration exceeds 7 g/dL. Several studies point to inferior outcomes when patients are transfused. Observational studies have confirmed that critically ill patients have frequent blood draws as part of their routine daily care. Cumulatively large volumes of blood are frequently taken, which contribute significantly towards the development of anaemia. Reducing iatrogenic blood loss may reduce the risk of developing anaemia and possibly the need for transfusion. Blood conservation devices may help to achieve this goal. The integration of blood conservation devices into routine care has been relatively slow in critical care. This review summarises the current evidence base and confirms that blood conservation devices do reduce the volume of iatrogenic blood loss. In the most recent studies, these devices have been shown to reduce transfusion requirements even in those intensive care units that follow a restrictive transfusion strategy.

Anemia and transfusion in critically ill pediatric patients: a review of etiology, management, and outcomes

This article describes the incidence and etiology of anemia in critically ill children. In addition, the article details the pathophysiology and clinical ramifications of anemia in this population. The use of transfused packed red blood cells as a therapy for anemia in critically ill patients is also discussed, including the indications for and complications associated with this practice as well as potential reasons for these complications. Finally, the article lists some therapeutic practices that may lessen the risks associated with transfusion, and briefly discusses the use of blood substitutes.

Update in critical care for the nephrologist: transfusion in nonhemorrhaging critically ill patients

A growing number of guidelines and recommendations advocate a restrictive transfusion strategy. Strong evidence exists that a hemoglobin threshold of less than 7 g/dL conserves resources and may improve outcomes in critically ill patients and that platelet counts greater than 10,000/μL are well tolerated. Patients with coronary artery disease can be safely managed with a restrictive transfusion strategy, utilizing a hemoglobin threshold of less than 7 or 8 g/dL; a threshold of less than 8 g/dL can be applied to patients with acute coronary syndromes. In the absence of coagulopathy with bleeding or high risk for bleeding, plasma transfusion should be withheld. Complications from transfusion are significant and previously under-recognized immunologic complications pose a more serious threat than infections. Erythropoietin and iron administration do not reduce transfusion needs in the critically ill. Interventions to reduce blood loss and educate clinicians are successful in reducing transfusion requirements.

Simulation of repetitive diagnostic blood loss and onset of iatrogenic anemia in critical care patients with a mathematical model

Anemia is prevalent among critical care patients and is attributed to pathologic and iatrogenic processes and bleeding. The extent that diagnostic blood loss contributes to anemia among adult critical care patients is controversial and multi-factorial. The aim of this study is to describe an erythrokinetic model that integrates rates of phlebotomy, erythropoiesis and red cell senescence with patient characteristics to predict the onset of iatrogenic anemia in an objective manner. Using sex-specific parameters, the model predicts that adults with (average body weight and average blood volume), initial hemoglobin concentration at mid-reference interval, active erythropoiesis and losing 53 mL of blood per day by phlebotomy would require 40-70 days to reach 70 g/L of hemoglobin. To mimic critical care patients with low initial hemoglobin and suppressed erythropoiesis, the influence of daily blood loss and total blood volume was predicted. Simultaneous lack of erythropoiesis, initial hemoglobin concentrations at the lower limit of the reference interval (110 g/L), low body weight and increased phlebotomy accelerated onset of ~70 g/L hemoglobin transfusion threshold to 9-14 days. This computer simulation depicts the extent that adult critical care patients with anemia risk factors could benefit from conservative test ordering practices and subsequent reduced diagnostic phlebotomy.