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

Jehovah's Witness Needing Critical Care: A Narrative Review on the Expanding Arsenal

Present day Jehovah's Witness (JW) religion accounts for 8.5 million followers. A tenant feature of the JW faith is religious objection to transfusions of blood and blood products. Interpatient variability, as it pertains to blood and blood products may occur; hence, a confidential interview will determine which products individual may consent to (Marsh and Bevan, 2002). This belief and practice place great restrictions on treating medical professionals in scenarios of life-threatening anaemia and active haemorrhage. The review to follow explores the physiological and pathophysiological consequences of severe anaemia. Non-blood transfusion practices are explored, many of which are potentially lifesaving. Particular attention is drawn to the evolving science involving artificial oxygen carriers and their use in emergency situations. A greater safety profile ensures its future use amongst religious objectors to be greatly beneficial. Intravenous iron supplementation has enjoyed a lively debate within the critical care community. A review of recent systematic and meta-analysis supports its use in the ICU; however, more investigation is needed into the complementary use of hepcidin.

Effectiveness of closed blood sampling systems in intensive care patients: a scoping review

BACKGROUND

Anemia associated with blood extraction for diagnostic purposes is a highly prevalent entity in intensive care units (ICU) for adults. The evidence recommends its prevention through different strategies, among which we can find the use of closed blood sampling systems (CBSS). Different experimental studies support the use of these devices.

OBJECTIVE

To identify knowledge gaps regarding the effectiveness of CBSS in ICU patients.

METHODS

Scoping review with search in PubMed, CINAHL, Embase, Cochrane Library and Joanna Briggs Institute databases, between September-2021 and September-2022. No time, language, or other limits were applied to ensure the recovery of all relevant studies. Gray literature sources: DART-Europe, OpenGrey and Google Scholar. Two researchers independently reviewed titles and abstracts and assessed full texts against the inclusion criteria. The following data was extracted for each study: design and sample, inclusion and exclusion criteria, variables, type of CBSS, results and conclusions.

RESULTS

18 articles were included in the final review, 11 clinical trials (RCTs) published between 1992 and 2014. Three systematic reviews were found, but they only analyzed the effect of CBSS in reducing blood loss, hemoglobin stabilization, and the need for transfusion. Five of the RCTs analyzed the risk of infection, one catheter complications, and two alterations in blood pressure readings.

CONCLUSIONS

The use of CBSS is recommended to reduce blood loss in ICUs. However, there are discrepancies about their ability to prevent anemia and/or the need for blood transfusion. Its use does not increase catheter-related infection rates or alter the measurement of mean arterial pressure.

Risk of abnormal uterine bleeding associated with high-affinity compared with low-affinity serotonin and norepinephrine reuptake inhibitors

BACKGROUND

Concerns have been raised about the potential association between selective serotonin reuptake inhibitors (SSRIs)/serotonin-norepinephrine reuptake inhibitors (SNRIs) and the risk of abnormal uterine bleeding (AUB), which may be influenced by the affinity of SSRIs/SNRIs for serotonin transporter. Thus, we assessed whether SSRIs/SNRIs with high-affinity for serotonin transporter are associated with AUB compared to SSRIs/SNRIs with low-affinity in non-pregnant women.

METHODS

Using the UK Clinical Practice Research Datalink, we identified a cohort of women aged 15-24 years, newly prescribed a high- or low-affinity SSRI/SNRI between 1990 and 2019. Confounding was addressed using standardized morbidity ratio weighting. We used weighted Cox proportional hazards models to estimate the hazard ratio (HR) and 95 % confidence interval (CI) of AUB associated with high-affinity compared with low-affinity SSRIs/SNRIs. We assessed the risk of anemia as a secondary outcome.

RESULTS

The cohort included 156,307 users of high-affinity SSRIs/SNRIs and 102,631 users of low-affinity SSRIs/SNRIs. High-affinity SSRIs/SNRIs were not associated with an increased risk of AUB compared with low-affinity SSRIs/SNRIs (incidence rates: 46.3 versus 42.4 per 1000 person-years, respectively; HR 1.01, 95 % CI 0.93-1.09). Duration of use, age, and comorbidities did not modify the risk. However, high-affinity SSRIs/SNRIs were associated with an increased risk of anemia (HR 1.29, 95 % CI 1.04-1.61) compared with low-affinity SSRIs/SNRIs.

LIMITATIONS

Residual confounding may still be present.

CONCLUSIONS

The risk of AUB did not differ between high- and low-affinity SSRIs/SNRIs. However, the potential risk of anemia suggests the need for monitoring and further investigation of the risk of AUB with these medications.

Pharmacotherapy for Reducing RBC Transfusion for Patients in the ICU: A Systematic Review and Network Meta-Analysis

OBJECTIVES

To determine optional therapeutic strategies by comparing monotherapies and combination therapies to reduce RBC transfusion requirement for patients in the ICU.

DATA SOURCES

MEDLINE, CENTRAL, and Embase were searched for studies published from database inception until July 2023.

DATA EXTRACTION

We included randomized controlled trials comparing erythropoiesis-stimulating agents (Epo), iron, combination therapy with iron and Epo, hypoxia-inducible factor prolyl hydroxylase inhibitor (HIF-PHI), vitamin D 3 (VD3), and placebo/no treatment. A frequentist network meta-analysis (NMA) was performed using a random effects model, and the confidence in NMA was rated.

DATA SYNTHESIS

Of 117 eligible studies, 75 studies (15,091 patients) were included in the quantitative analysis. Compared with placebo/no treatment, the combination therapy reduces the requirement for RBC transfusion (risk ratio [RR]: 0.60; 95% CI, 0.49-0.74; confidence rating: moderate). The Epo or iron monotherapy may reduce the requirement for RBC transfusion (RR: 0.81; 95% CI, 0.63-1.04; confidence rating: low; RR: 0.83; 95% CI, 0.70-0.98; confidence rating: low, respectively). Combination therapy may not increase the prevalence of both venous thromboembolism (VTE) (RR: 0.73; 95% CI, 0.25-2.08; confidence rating: low) and infection. Epo monotherapy may not increase the prevalence of VTE but may increase that of infections (RR: 1.27; 95% CI, 0.94-1.73; confidence rating: low). Iron monotherapy may not increase the prevalence of both VTE and infection. Evidence for VD3 and HIF-PHI remains uncertain.

CONCLUSIONS

Combination therapy with iron and Epo likely reduces the requirement for RBC transfusion and may be less harmful than other therapies.

Intravenous iron for critically ill children. Comparison of three dose regimens

BACKGROUND

Anemia is extremely common among patients admitted to pediatric intensive care. Alternative treatments to transfusions such as intravenous iron must be considered. There are no published data for a prospective intravenous (IV) iron study focused in the critically ill children. The objective is to examine the safety and efficacy of intravenous iron sucrose infusion to manage anemia in pediatric critical care. A secondary objective is to examine the effect of different dose regimens of iron sucrose (3, 5, and 7 mg/kg dose).

PROCEDURE

Prospective investigation of intravenous iron sucrose utilization at a tertiary pediatric intensive care unit between October 2017 and November 2022.

RESULTS

In all 115 patients received a total of 616 infusions of IV iron. Transferrin saturation index (TSI) was the most common altered iron deficiency biomarker (91.8%). After IV iron treatment, hemoglobin showed a significant increase within a 30-day follow-up (9.2 vs. 11.6 g/dL, p < .001). There was also a significant improvement in TSI and serum iron (p < .001). Iron deficit replacement was higher in the 7 mg/kg dose group (94%) compared to 85.9% in the 5 mg/kg regimen and 77.5% in the lower dose group (p = .008), requiring less doses and a shorter time. Very few mild adverse reactions were reported (1.3% of infusions), with no differences between groups. The most frequent adverse effect was gastrointestinal in three cases. There were no anaphylaxis-like or other serious/life-threatening adverse effects.

CONCLUSIONS

This is the first study to evaluate intravenous iron therapy in pediatric critical care, providing preliminary evidence of safety and efficacy of IV iron sucrose. The 7 mg/kg dose regimen showed higher iron deficit replacement in a shorter time, which could be beneficial in critically ill children.

Development and Validation of Machine Learning-Based Models to Predict In-Hospital Mortality in Life-Threatening Ventricular Arrhythmias: Retrospective Cohort Study

BACKGROUND

Life-threatening ventricular arrhythmias (LTVAs) are main causes of sudden cardiac arrest and are highly associated with an increased risk of mortality. A prediction model that enables early identification of the high-risk individuals is still lacking.

OBJECTIVE

We aimed to build machine learning (ML)-based models to predict in-hospital mortality in patients with LTVA.

METHODS

A total of 3140 patients with LTVA were randomly divided into training (n=2512, 80%) and internal validation (n=628, 20%) sets. Moreover, data of 2851 patients from another database were collected as the external validation set. The primary output was the probability of in-hospital mortality. The discriminatory ability was evaluated by the area under the receiver operating characteristic curve (AUC). The prediction performances of 5 ML algorithms were compared with 2 conventional scoring systems, namely, the simplified acute physiology score (SAPS-II) and the logistic organ dysfunction system (LODS).

RESULTS

The prediction performance of the 5 ML algorithms significantly outperformed the traditional models in predicting in-hospital mortality. CatBoost showed the highest AUC of 90.5% (95% CI 87.5%-93.5%), followed by LightGBM with an AUC of 90.1% (95% CI 86.8%-93.4%). Conversely, the predictive values of SAPS-II and LODS were unsatisfactory, with AUCs of 78.0% (95% CI 71.7%-84.3%) and 74.9% (95% CI 67.2%-82.6%), respectively. The superiority of ML-based models was also shown in the external validation set.

CONCLUSIONS

ML-based models could improve the predictive values of in-hospital mortality prediction for patients with LTVA compared with traditional scoring systems.

Erythropoietin to treat anaemia in critical care patients: a multicentre feasibility study

Anaemia is common and associated with poor outcomes during and after critical illness. The use of erythropoietin to treat such anaemia is controversial with older studies showing mixed results. In this study, we aimed to evaluate the feasibility of performing a large multicentre randomised controlled trial of erythropoietin in this setting. We randomly allocated patients staying in the ICU for ≥ 72 h with haemoglobin ≤ 120 g.l-1 to either a weekly injection of erythropoietin (40,000 iu, maximum of five injections) or placebo (saline). The primary endpoint was feasibility (as measured by recruitment, randomisation and follow-up rates, and protocol compliance). Secondary endpoints included biological efficacy and clinical outcomes. Forty-two participants were recruited and randomly allocated, all participants received the allocated intervention, but one withdrew their consent and refused the use of their data, leaving 20 in the erythropoietin group and 21 in placebo group. Follow-up was completed for all patients who survived. The overall recruitment rate was 73.7% with 8.4 participants recruited on average per month. The last haemoglobin measured before hospital discharge (or death) was similar between the groups with a mean (SD) haemoglobin of 107 (21) vs. 95 (25) g.l-1 , mean difference (95%CI) 11 (-4-26), g.l-1 , p = 0.154. A large, multicentre randomised controlled trial of erythropoietin to treat anaemia in ICU patients is feasible and necessary to determine effects of erythropoietin on mortality in ICU anaemic patients.

Anaemia in the first week may be associated with long-term mortality among critically ill patients: propensity score-based analyses

BACKGROUND

Anaemia is highly prevalent in critically ill patients; however, the long-term effect on mortality remains unclear.

METHODS

We retrospectively included patients admitted to the medical intensive care units (ICUs) during 2015-2020 at the Taichung Veterans General Hospital. The primary outcome of interest was one-year mortality, and hazard ratios (HRs) with 95% confidence intervals (CIs) were determined to assess the association. We used propensity score matching (PSM) and propensity score matching methods, including inverse probability of treatment weighting (IPTW) as well as covariate balancing propensity score (CBPS), in the present study.

RESULTS

A total of 7,089 patients were eligible for analyses, and 45.0% (3,189/7,089) of them had anaemia, defined by mean levels of haemoglobin being less than 10 g/dL. The standardised difference of covariates in this study were lower than 0.20 after matching and weighting. The application of CBPS further reduced the imbalance among covariates. We demonstrated a similar association, and adjusted HRs in original, PSM, IPTW and CBPS populations were 1.345 (95% CI 1.227-1.474), 1.265 (95% CI 1.145-1.397), 1.276 (95% CI 1.142-1.427) and 1.260 (95% CI 1.125-1.411), respectively.

CONCLUSIONS

We used propensity score-based analyses to identify that anaemia within the first week was associated with increased one-year mortality in critically ill patients.

Patient Blood Management, Anemia, and Transfusion Optimization Across Surgical Specialties

Patient blood management (PBM) is a systematic, evidence-based approach to improve patient outcomes by managing and preserving a patient's own blood and minimizing allogenic transfusion need and risk. According to the PBM approach, the goals of perioperative anemia management include early diagnosis, targeted treatment, blood conservation, restrictive transfusion except in cases of acute and massive hemorrhage, and ongoing quality assurance and research efforts to advance overall blood health.

[Intensive Care in Heart Surgery - is All Now Different?]

With approximately 100000 operations performed in Germany per year, cardiac surgery is among the surgical specialties that require intensive care tratment most frequently. Although all therapeutic aspects of ICU treatment are of high importance among cardiac surgery patients, there is a focus on hemodynamics with the overarching goal of sufficient oxygen delivery. Patients undergoing cardiac surgery are particularily prone to hemodynamic instability and low cardiac output syndrome, potentially culminating into cardiogenic shock. This article presents an overview of essential elements of intensive care medicine in cardiac surgery, paying special attention to hemodynamic monitoring, low cardiac output syndrome, inotropy, cardiac arrhyhmia, perioperative myocardial infarction, and patient blood management.

The role of iron in chronic inflammatory diseases: from mechanisms to treatment options in anemia of inflammation

Anemia of inflammation (AI) is a highly prevalent comorbidity in patients affected by chronic inflammatory disorders, such as chronic kidney disease, inflammatory bowel disease, or cancer, that negatively affect disease outcome and quality of life. The pathophysiology of AI is multifactorial, with inflammatory hypoferremia and iron-restricted erythropoiesis playing a major role in the context of disease-specific factors. Here, we review the recent progress in our understanding of the molecular mechanisms contributing to iron dysregulation in AI, the impact of hypoferremia and anemia on the course of the underlying disease, and (novel) therapeutic strategies applied to treat AI.

Relevance of pre-existing anaemia for patients admitted for acute coronary syndrome to an intensive care unit: a retrospective cohort analysis of 7418 patients

Aims

Patients with acute coronary syndrome (ACS) frequently suffer from anaemia, but its role in patients admitted to an intensive care unit (ICU) is unclear. This analysis evaluates the prognostic relevance of different degrees of anaemia and their specific impact on disease severity and the outcome in critically ill ACS patients.

Methods and results

and results The multi-centre electronic Intensive Care Unit Collaborative Research Database was used, and all patients admitted with ACS were included in a retrospective analysis. Anaemia and its degrees were defined according to the criteria by the World Health Organization. A multi-level logistic regression analysis was used to fit three sequential regression models for the binary primary outcome of hospital mortality. A total of 7418 patients were included; 3437 patients (46%) had anaemia on admission. Patients with anaemia were significantly older [61 (53–70) vs. 70 (61–78) years, P < 0.001], more often female (P < 0.001), and required an increased rate of vasopressor use (P < 0.001) and mechanical ventilation (P < 0.001). With the higher Sequential organ failure assessment score (1 vs. 2; P < 0.001) and Acute Physiology And Chronic Health Evaluation (35 vs. 47; P < 0.001) scores, a higher degree of anaemia was associated with prolonged ICU stay (2 vs. 5 days, P < 0.001). Even patients with mild anaemia needed significantly from more intensive treatment and suffered worse outcome. Intensive care unit and hospital mortality were inversely associated with haemoglobin levels.

Conclusion

Nearly half of critically ill patients with ACS suffer from anaemia, which is associated with increased illness severity, complex ICU procedures, and mortality—even in mild anaemia. Haemoglobin on admission is an independent factor for adverse outcome.

Week-One Anaemia was Associated with Increased One-Year Mortality in Critically Ill Surgical Patients

BACKGROUND

Anaemia has a deleterious effect on surgical patients, but the long-term impact of anaemia in critically ill surgical patients remains unclear.

METHODS

We enrolled consecutive patients who were admitted to surgical intensive care units (ICUs) at a tertiary referral centre in central Taiwan between 2015 and 2020. We used both Cox proportional hazards analysis and propensity score-based analyses, including propensity score matching (PSM), inverse probability of treatment weighting (IPTW), and covariate balancing propensity score (CBPS) to determine hazard ratios (HRs) and 95% confidence intervals (CIs) for one-year mortality.

RESULTS

A total of 7,623 critically ill surgical patients were enrolled, and 29.9% (2,280/7,623) of them had week-one anaemia (haemoglobin <10 g/dL). We found that anaemia was independently associated with an increased risk of one-year mortality after adjustment for relevant covariates (aHR, 1.170; 95% CI, 1.045-1.310). We further identified a consistent strength of association between anaemia and one-year mortality in propensity score-based analyses, with the adjusted HRs in the PSM, IPTW, and CBPS were 1.164 (95% CI 1.025-1.322), 1.179 (95% CI 1.030-1.348), and 1.181 (1.034-1.349), respectively.

CONCLUSIONS

We identified the impact on one-year mortality of anaemia in critically ill surgical patients, and more studies are needed to validate our findings.

Iatrogenic anaemia and transfusion thresholds in ICU patients with COVID-19 disease at a tertiary care hospital

BACKGROUND

Patients with severe COVID-19 disease frequently develop anaemia as the result of multiple mechanisms and often receive transfusions. The aims of this study were to assess the impact of repeated blood samplings on patients' anaemic state using standard-volume tubes, in comparison with the hypothetical use of low-volume tubes and to evaluate the transfusion policy adopted.

STUDY DESIGN AND METHODS

Transfusion data of mechanically ventilated non-bleeding patients with COVID-19 disease hospitalized in ICU for a minimum of 20 days were recorded. The total volume of blood drawn for samplings with standard-volume tubes and the corresponding red blood cell mass (RBCM) removed during hospitalization for each patient were calculated and compared with the hypothetical use of low-volume tubes.

RESULTS

Twenty-four patients fulfilled the inclusion criteria. Ten patients were anaemic at ICU admission (41.7 %). Overall, 6658 sampling tubes were employed, for a total of 16,786 mL of blood. The median RBCM subtracted by blood samplings per patient accounted for about one third of the total patients' RBCM decrease until discharge. The use of low-volume tubes would have led to a median saving of about one third of the drawn RBCM. Eleven patients were transfused (45.8 %) at a mean Hb value of 7.7 (± 0.5) g/dL.

CONCLUSION

The amount of blood drawn for sampling has a significant role in the development of anaemia and the use of low-volume tubes could minimize the problem. Large high-powered studies are warranted to assess the more appropriate transfusion thresholds in non-bleeding critically ill patients with COVID-19 disease.

Impact of treating iron deficiency, diagnosed according to hepcidin quantification, on outcomes after a prolonged ICU stay compared to standard care: a multicenter, randomized, single-blinded trial

BACKGROUND

Anemia is a significant problem in patients on ICU. Its commonest cause, iron deficiency (ID), is difficult to diagnose in the context of inflammation. Hepcidin is a new marker of ID. We aimed to assess whether hepcidin levels would accurately guide treatment of ID in critically ill anemic patients after a prolonged ICU stay and affect the post-ICU outcomes.

METHODS

In a controlled, single-blinded, multicenter study, anemic (WHO definition) critically ill patients with an ICU stay ≥ 5 days were randomized when discharge was expected to either intervention by hepcidin treatment protocol or control. In the intervention arm, patients were treated with intravenous iron (1 g of ferric carboxymaltose) when hepcidin was < 20 μg/l and with intravenous iron and erythropoietin for 20 ≤ hepcidin < 41 μg/l. Control patients were treated according to standard care (hepcidin quantification remained blinded). Primary endpoint was the number of days spent in hospital 90 days after ICU discharge (post-ICU LOS). Secondary endpoints were day 15 anemia, day 30 fatigue, day 90 mortality and 1-year survival.

RESULTS

Of 405 randomized patients, 399 were analyzed (201 in intervention and 198 in control arm). A total of 220 patients (55%) had ID at discharge (i.e., a hepcidin < 41 μg/l). Primary endpoint was not different (medians (IQR) post-ICU LOS 33(13;90) vs. 33(11;90) days for intervention and control, respectively, median difference - 1(- 3;1) days, p = 0.78). D90 mortality was significantly lower in intervention arm (16(8%) vs 33(16.6%) deaths, absolute risk difference - 8.7 (- 15.1 to - 2.3)%, p = 0.008, OR 95% IC, 0.46, 0.22-0.94, p = 0.035), and one-year survival was improved (p = 0.04).

CONCLUSION

Treatment of ID diagnosed according to hepcidin levels did not reduce the post-ICU LOS, but was associated with a significant reduction in D90 mortality and with improved 1-year survival in critically ill patients about to be discharged after a prolonged stay.

TRIAL REGISTRATION

www.clinicaltrial.gov NCT02276690 (October 28, 2014; retrospectively registered).