Optimal Transfusion Threshold Research Articles

Analysis of platelet transfusion efficacy during extracorporeal membrane oxygenation (ECMO) treatment in pediatric patients post-cardiac surgery-a retrospective cohort study.

Postoperative extracorporeal membrane oxygenation (ECMO) may be necessary for pediatric patients following cardiac surgery, with associated risks of thrombocytopenia and bleeding. Prophylactic platelet transfusions are utilized to mitigate these risks, but the effectiveness of platelet transfusion cannot be reliably predicted. The aim of this study was to investigate the effect of platelet transfusion during postoperative treatment with ECMO in children undergoing cardiac surgery and to explore the optimal transfusion thresholds to reduce the number of platelet transfusions in patients and reduce the risk of death. We included in our study patients from the Pediatric Cardiac Surgery Department at the First Affiliated Hospital of Tsinghua University who underwent cardiac surgery and received ECMO treatment from January 1, 2019, to December 31, 2023, and received platelets transfusion at least once during the ECMO therapy. The platelet counts were determined both before and 24 hours posttransfusion of the platelet product. The corrected count increment (CCI) was calculated for the effectiveness estimation of platelet transfusion. The research subjects were divided into 3 groups based on the platelet count before transfusion (pretransfusion platelet count ≤30×109/L was the low-threshold group, pretransfusion count 31-50×109/L was the medium-threshold group, and ≥51×109/L was the high-threshold group) and the effective rates of each group were calculated. A total of 11 patients received 47 platelet transfusions, an average of 4.27 ± 1.67 per patient. According to the 24-hour postinfusion platelet (Plt) corrected critical control increase index (24-hour CCI) ≥4500, the infusion was considered to be effective, and ineffective when the CCI was <4500. Out of these, 22 transfusions (46.8%) proved effective, whereas 25 (53.2%) were deemed ineffective. The effective transfusion rates across the 3 groups were 69.2%, 50%, and 27.7%, respectively. The efficacy of platelet transfusion may be higher if a low threshold of platelet transfusion is chosen during ECMO treatment, on the premise of ensuring life safety.

Restrictive vs Liberal Transfusion Strategy in Patients With Acute Brain Injury

Blood transfusions are commonly administered to patients with acute brain injury. The optimal hemoglobin transfusion threshold is uncertain in this patient population. To assess the impact on neurological outcome of 2 different hemoglobin thresholds to guide red blood cell transfusions in patients with acute brain injury. Multicenter, phase 3, parallel-group, investigator-initiated, pragmatic, open-label randomized clinical trial conducted in 72 intensive care units across 22 countries. Eligible patients had traumatic brain injury, aneurysmal subarachnoid hemorrhage, or intracerebral hemorrhage; hemoglobin values below 9 g/dL within the first 10 days after injury; and an expected intensive care unit stay of at least 72 hours. Enrollment occurred between September 1, 2017, and December 31, 2022. The last day of follow-up was June 30, 2023. Eight hundred fifty patients were randomly assigned to undergo a liberal (transfusion triggered by hemoglobin <9 g/dL; n = 408) or a restrictive (transfusion triggered by hemoglobin <7 g/dL; n = 442) transfusion strategy over a 28-day period. The primary outcome was occurrence of an unfavorable neurological outcome, defined as a Glasgow Outcome Scale Extended score between 1 and 5, at 180 days following randomization. There were 14 prespecified serious adverse events, including occurrence of cerebral ischemia after randomization. Among 820 patients who completed the trial (mean age, 51 years; 376 [45.9%] women), 806 had available data on the primary outcome, 393 in the liberal strategy group and 413 in the restrictive strategy group. The liberal strategy group received a median of 2 (IQR, 1-3) units of blood, and the restrictive strategy group received a median of 0 (IQR, 0-1) units of blood, with an absolute mean difference of 1.0 unit (95% CI, 0.87-1.12 units). At 180 days after randomization, 246 patients (62.6%) in the liberal strategy group had an unfavorable neurological outcome compared with 300 patients (72.6%) in the restrictive strategy group (absolute difference, -10.0% [95% CI, -16.5% to -3.6%]; adjusted relative risk, 0.86 [95% CI, 0.79-0.94]; P = .002). The effect of the transfusion thresholds on neurological outcome at 180 days was consistent across prespecified subgroups. In the liberal strategy group, 35 (8.8%) of 397 patients had at least 1 cerebral ischemic event compared with 57 (13.5%) of 423 in the restrictive strategy group (relative risk, 0.65 [95% CI, 0.44-0.97]). Patients with acute brain injury and anemia randomized to a liberal transfusion strategy were less likely to have an unfavorable neurological outcome than those randomized to a restrictive strategy. ClinicalTrials.gov Identifier: NCT02968654.

Comparison of liberal versus restrictive transfusion strategies after hip surgery in patients with coronary artery disease: a post hoc analysis of the FOCUS trial

BackgroundThere are no clear recommendations for optimal transfusion thresholds for patients with coronary artery disease who undergo noncardiac surgery. By comparing restrictive and liberal transfusion strategies for coronary artery disease combined with hip surgery, this study hopes to provide recommendations for transfusion strategies in this special population.MethodsA total of 805 patients from the FOCUS trial (Transfusion Trigger Trial for Functional Outcomes in Cardiovascular Patients Undergoing Surgical Hip Fracture Repair) with coronary artery disease combined with hip surgery were divided into two groups based on transfusion thresholds: restricted transfusion (a hemoglobin level of 8 g/deciliter) and liberal transfusion (a hemoglobin threshold of 10 g/deciliter). The primary outcome of this study was a composite endpoint including in-hospital death, myocardial infarction, unstable angina, and acute heart failure. The secondary endpoints included other in-hospital adverse events and 30- and 60-day follow-up events. Analyses were performed by intention to treat.ResultsExcept for the proportion of congestive heart failure patients, the baseline levels of the two groups were comparable. The median number of transfusion units in the liberal transfusion group was 2 units, and the median transfusion volume in the restricted transfusion group was 0 units. The primary outcome was not significantly different between the two groups (9.2% vs. 9.4%, p = 0.91). The incidence of in-hospital myocardial infarction events was lower in the liberal transfusion group than in the restricted transfusion group (3.2% vs. 6.2%) (OR = 0.51, P = 0.048). The remaining in-hospital endpoint events, except for myocardial infarction, were not significantly different between the two groups. The 30-day and 60-day endpoints of death and inability to walk independently were not significantly different between the two groups, with ORs (95% CI) of 1.00 (0.75–1.31) and 1.06 (0.80–1.41), respectively. We also found no interaction between transfusion strategies and factors such as age, sex, or multiple underlying comorbidities at the 60-day follow-up.ConclusionsThere was no significant difference in the in-hospital, 30-day or 60-day outcome endpoints between the two groups. However, this study demonstrated that a liberal transfusion strategy tends to reduce the incidence of in-hospital myocardial infarction events in patients with coronary artery disease combined with hip surgery compared to a restrictive transfusion strategy. More high-quality studies should be designed to investigate the optimal transfusion threshold in patients with coronary artery disease treated without cardiac surgery.

Assessing the impact of transfusion thresholds in patients with septic acute kidney injury: a retrospective study.

Sepsis is a severe condition that often leads to complications such as acute kidney injury, which significantly increases morbidity and mortality rates. Septic AKI (S-AKI) is common in ICU patients and is associated with poor outcomes. However, there is no consensus on the optimal transfusion threshold for achieving the best clinical results. This retrospective study aims to investigate the relationship between different transfusion thresholds during hospitalization and the prognosis of septic AKI. Data from patients with S-AKI was extracted from MIMIC-IV. Based on the lowest hemoglobin level 24 h before transfusion, patients were divided into high-threshold (≥7 g/L) and low-threshold (<7 g/L) groups. We compared the outcomes between these two groups, including hospital and ICU mortality rates as primary outcomes, and 30 days, 60 days, and 90 days mortality rates, as well as duration of stay in ICU and hospital as secondary outcomes. A total of 5,654 patients were included in our study. Baseline characteristics differed significantly between the two groups, with patients in the low-threshold group generally being younger and having higher SOFA scores. After performing propensity score matching, no significant differences in survival rates were found between the groups. However, patients in the low-threshold group had a longer overall hospital stay. A lower transfusion threshold does not impact the mortality rate in S-AKI patients, but it may lead to a longer hospital stay.

Anemia and Optimal Transfusion Thresholds in Brain-Injured Patients: A Narrative Review of the Literature.

Anemia is a highly prevalent condition that may compromise oxygen delivery to vital organs, especially among the critically ill. Although current evidence supports the adoption of a restrictive transfusion strategy and threshold among the nonbleeding critically ill patient, it remains unclear whether this practice should apply to the brain-injured patient, given the predisposition to cerebral ischemia in this patient population, in which even nonprofound anemia may exert a detrimental effect on clinical outcomes. The purpose of this review is to provide an overview of the pathophysiological changes related to impaired cerebral oxygenation in the brain-injured patient and to present the available evidence on the effect of anemia and varying transfusion thresholds on the clinical outcomes of patients with acute brain injury.

Potential benefits of restrictive transfusion in upper gastrointestinal bleeding: a systematic review and meta-analysis of randomised controlled trials

The optimal red blood cell (RBC) transfusion strategy in acute gastrointestinal bleeding (GIB) is debated. We aimed to assess the efficacy and safety of restrictive compared to liberal transfusion strategies in the GIB population. We searched PubMed, CENTRAL, Embase, and Web of Science for randomised controlled trials on 15.01.2022 without restrictions. Studies comparing lower to higher RBC transfusion thresholds after GIB were eligible. We used the random effect model and calculated pooled mean differences (MD), risk ratios (RR) and proportions with 95% confidence intervals (CI) to calculate the overall effect size. The search yielded 3955 hits. All seven eligible studies reported on the upper GIB population. Restrictive transfusion did not increase the in-hospital- (RR: 0.94; CI 0.46, 1.94) and 30-day mortality (RR: 0.71; CI 0.35, 1.45). In-hospital- and 28 to 45-day rebleeding rate was also not higher with the restrictive modality (RR: 0.67; CI 0.30, 1.50; RR:0.75; CI 0.49, 1.16, respectively). Results of individual studies showed a lower rate of transfusion reactions and post-transfusion intervention if the transfusion was started at a lower threshold. A haemoglobin threshold > 80 g/L may result in a higher untoward outcome rate. In summary, restrictive transfusion does not appear to lead to a higher rate of significant clinical endpoints. The optimal restrictive transfusion threshold should be further investigated.

Transfusion thresholds: the need for a patient-centered approach in hematologic disorders that require chronic transfusion therapy.

Transfusion is an essential life-sustaining treatment for many patients. However, unnecessary transfusion has been reported to be related to worse patient outcomes. Further, owing to the recent pandemic, blood supply has been more challenging to maintain. Many studies have been conducted to elucidate the optimal transfusion threshold for many clinical conditions, and most suggested that a restrictive transfusion strategy has advantages over a liberal transfusion strategy. Hematologic disorders, which require chronic transfusion in many cases, have not been the main subjects of such studies, and only little evidence is available regarding the optimal transfusion threshold in these patients. According to several recent studies, a liberal transfusion strategy is preferable for patients with hematologic disorders due to their quality of life. A patient-centered approach is needed for proper management of hematologic disorders.

Hemoglobin modulation affects physiology and patient reported outcomes in anemic and non-anemic subjects: An umbrella review.

Background: An abnormal hemoglobin concentration has a substantial effect on a person's quality of life and physiology. Lack of tools that effectively evaluate hemoglobin-related outcomes leads to uncertainty regarding optimal hemoglobin levels, transfusion thresholds and treatment targets. We therefore aim to summarize reviews that assess the effects of hemoglobin modulation on the human physiology at various baseline hemoglobin levels, and identify gaps in existing evidence. Methods: We conducted an umbrella review of systematic reviews. PubMed, MEDLINE (OVID), Embase, Web of Science, Cochrane Library and Emcare were searched from inception to the 15th of April 2022 for studies that reported on physiological and patient reported outcomes following a hemoglobin change. Results: Thirty-three reviews were included of which 7 were scored as of high quality and 24 of critically low quality using the AMSTAR-2 tool. The reported data generally show that an increase in hemoglobin leads to improvement of patient reported and physical outcomes in anaemic and non-anaemic subjects. At lower hemoglobin levels, the effect of a hemoglobin modulation on quality of life measures appears more pronounced. Conclusion: This overview has revealed many knowledge gaps due to a lack of high-quality evidence. For chronic kidney disease patients, a clinically relevant benefit of increasing the hemoglobin levels up until 12g/dL was found. However, a personalized approach remains necessary due to the many patient-specific factors that affect outcomes. We strongly encourage future trials to incorporate physiological outcomes as objective parameters together with subjective, but still very important, patient reported outcome measures.

Restrictive versus liberal transfusion for anemic patients with acute myocardial infarction: Systematic review and meta-analysis

• Meta-analysis of RCTs comparing transfusion thresholds for patients with acute MI and anemia failed to exclude either appreciable harm or benefit. • The mechanism by which blood transfusions are thought to improve outcomes in patients with MI and anemia requires further investigation. • Additional research utilizing published results from larger randomized controlled trials is needed to understand the relative safety of liberal to restrictive blood transfusion strategies and overcome the quality limitations of current evidence. The optimal blood transfusion threshold for patients with acute myocardial infarction (MI) and anemia is unclear. This meta-analysis aimed to assess the safety of restrictive transfusion to liberal thresholds. We searched MEDLINE, EMBASE, Web of Science, and CENTRAL for randomized controlled trials comparing different transfusion strategies in patients with acute MI. Two independent reviewers screened the studies for inclusion, extracted data, evaluated methodological quality, and assessed the quality of evidence. Primary outcomes were all measured at 30-days post-randomization and included: All-cause mortality, heart failure, recurrent MI, and stroke. A random-effects model was used. Our searches yielded a total of 5980 unique results. Three studies were eligible and included in the analysis (n = 821 patients). In all studies, the restrictive and liberal thresholds were equivalent to 8g/dL and 10g/dL hemoglobin, respectively. There was no significant difference in all-cause mortality (RR = 0.63; 95% CI 0.15 to 2.66; P = 0.53; I 2 = 59%), heart failure (RR = 1.17; 95% CI 0.31 to 4.34; P = 0.82; I 2 = 70%), recurrence of MI (RR = 1.61; 95% CI 0.65 to 4.02; P = 0.30; I 2 = 0%), or stroke (RR = 1.41; 95% CI 0.27 to 7.43; P = 0.69; I 2 = 0%). Our meta-analysis found no significant difference in the primary outcomes between transfusion strategies for patients with acute MI and anemia. Results from trials with larger sample sizes is needed to clarify the dilemma between transfusion strategies in this population.

RBC Transfusion in Venovenous Extracorporeal Membrane Oxygenation: A Multicenter Cohort Study.

In the general critical care patient population, restrictive transfusion regimen of RBCs has been shown to be safe and is yet implemented worldwide. However, in patients on venovenous extracorporeal membrane oxygenation, guidelines suggest liberal thresholds, and a clear overview of RBC transfusion practice is lacking. This study aims to create an overview of RBC transfusion in venovenous extracorporeal membrane oxygenation. Mixed method approach combining multicenter retrospective study and survey. Sixteen ICUs worldwide. Patients receiving venovenous extracorporeal membrane oxygenation between January 2018 and July 2019. None. The primary outcome was the proportion receiving RBC, the amount of RBC units given daily and in total. Furthermore, the course of hemoglobin over time during extracorporeal membrane oxygenation was assessed. Demographics, extracorporeal membrane oxygenation characteristics, and patient outcome were collected. Two-hundred eight patients received venovenous extracorporeal membrane oxygenation, 63% male, with an age of 55 years (45-62 yr), mainly for acute respiratory distress syndrome. Extracorporeal membrane oxygenation duration was 9 days (5-14 d). Prior to extracorporeal membrane oxygenation, hemoglobin was 10.8 g/dL (8.9-13.0 g/dL), decreasing to 8.7 g/dL (7.7-9.8 g/dL) during extracorporeal membrane oxygenation. Nadir hemoglobin was lower on days when a transfusion was administered (8.1 g/dL [7.4-9.3 g/dL]). A vast majority of 88% patients received greater than or equal to 1 RBC transfusion, consisting of 1.6 U (1.3-2.3 U) on transfusion days. This high transfusion occurrence rate was also found in nonbleeding patients (81%). Patients with a liberal transfusion threshold (hemoglobin > 9 g/dL) received more RBC in total per transfusion day and extracorporeal membrane oxygenation day. No differences in survival, hemorrhagic and thrombotic complication rates were found between different transfusion thresholds. Also, 28-day mortality was equal in transfused and nontransfused patients. Transfusion of RBC has a high occurrence rate in patients on venovenous extracorporeal membrane oxygenation, even in nonbleeding patients. There is a need for future studies to find optimal transfusion thresholds and triggers in patients on extracorporeal membrane oxygenation.

Impact of Perioperative Blood Transfusion in Anemic Patients Undergoing Infra Inguinal Bypass

Patients who present with lower extremity ischemia are frequently anemic and the optimal transfusion threshold for this cohort remains controversial. We sought to evaluate the impact of blood transfusion on postoperative major adverse cardiac events (MACE), including myocardial infarction, dysrhythmia, stroke, congestive heart failure, and 30-day mortality for these patients. All consecutive patients who underwent infra-inguinal bypass at our institution from 2011 to 2020 were included. Perioperative red blood cell transfusion was the primary exposure, and the primary outcome was MACE. Univariate and multivariable analyses were performed to assess the impact of patient and procedural variables, including red blood cell transfusion, stratified by hemoglobin (Hgb) nadir: <7, 7-8, and >8 g/dL. Of the 287 patients reviewed for analysis, 146 (50.9%) had a perioperative transfusion (mean: 1.6 ± 3 units). Patients who received a transfusion had a mean nadir Hgb of 8.3 ± 1.0 g/dL, compared to 10.1 ± 1.7 g/dL without a transfusion. The overall incidence of MACE was 15.7% (45 of 287 patients). Univariate analysis demonstrated that MACE was associated with blood transfusion (P=0.009), lower Hgb nadir (P=0.02), and higher blood loss (P=0.003). On multivariate analysis, transfusion was independently associated with MACE for patients with a Hgb nadir >8 g/dL (OR: 3.09; P=0.006), but not for patients with Hgb nadir 7-8 g/dL (OR: 0.818; P=0.77). Additionally, patients with MACE had significantly longer length of hospital stay than for patients without (13 vs. 7.7 days, P=0.001). For patients undergoing infra-inguinal bypass, receiving a red blood cell transfusion with a Hgb nadir >8 g/dL was associated with a 3-fold increase in MACE, with nearly twice the length of stay. For patients with a Hgb 7-8 g/dL, transfusion did not increase or reduce the incidence of MACE. These findings suggest no benefit of blood transfusion for patients with Hgb nadir >7 g/dL and harm for Hgb >8 g/dL, however causation cannot be proven due to the retrospective nature of the study and randomized studies are needed to confirm or refute these findings.

Red Blood Cell Transfusion Practices for Patients With Cervical Cancer Undergoing Radiotherapy

Packed red blood cell (PRBC) transfusions are used to treat anemia in patients with cervical cancer undergoing radiotherapy (RT) owing to concerns of hypoxia-induced radioresistance. In the absence of high-quality evidence informing transfusion practices for patients receiving external beam RT (EBRT) and brachytherapy, various arbitrary hemoglobin target levels are used worldwide. To develop consensus statements to guide PRBC transfusion practices in patients with cervical cancer receiving curative-intent RT with EBRT and brachytherapy. This international Delphi consensus study was completed between November 1, 2019, and July 31, 2020. A total of 63 international clinical experts in gynecologic radiation oncology were invited; 39 (62%) accepted and consented to participate. Consensus building was achieved using a 3-round anonymous Delphi consensus method. Participants rated their agreement or disagreement with statements using a 5-point Likert scale. An a priori threshold of 75% or more was required for consensus. The preplanned primary outcome of this study was to assess hemoglobin transfusion thresholds and targets for both EBRT and brachytherapy by expert consensus. Response rates of 100% (39 of 39), 92% (36 of 39), and 97% (35 of 36) were achieved for the first, second, and third rounds of surveys, respectively. Twenty-three experts (59%) practiced in Canada, 11 (28%) in the United States, 3 (8%) in South America, 1 (3%) in Europe, and 1 (3%) in Asia. Consensus was reached for 44 of 103 statements (43%), which were combined to form the final 27-statement consensus guideline. No specific hemoglobin transfusion threshold was agreed on by consensus for EBRT or brachytherapy. By consensus (89% [31 of 35]), a hemoglobin transfusion target for patients who receive a PRBC transfusion should be 9 g/dL or more and less than 12 g/dL. This study presents the first international expert consensus guideline informing PRBC transfusion practices for patients with cervical cancer undergoing EBRT and brachytherapy. A minimum hemoglobin transfusion target of 9 g/dL was endorsed to balance tumor radiosensitivity with appropriate use of a scarce resource. Randomized clinical trials are required to evaluate the optimal transfusion threshold and target that maximize clinical benefit in this patient population.

Anemia after Pediatric Congenital Heart Surgery.

The postoperative course of infants following congenital heart surgery is associated with significant blood loss and anemia. Optimal transfusion thresholds for cardiac surgery patients while in pediatric intensive care unit (PICU) remain a subject of debate. The goal of this study is to describe the epidemiology of anemia and the transfusion practices during the PICU stay of infants undergoing congenital heart surgery. A retrospective cohort study was performed in a PICU of a tertiary university-affiliated center. Infants undergoing surgery for congenital heart disease (CDH) before 6 weeks of age between February 2013 and June 2019 and who were subsequently admitted to the PICU were included. We identified 119 eligible patients. Mean age at surgery was 11 ± 7 days. Most common cardiac diagnoses were d-Transposition of the Great Arteries (55%), coarctation of the aorta (12.6%), and tetralogy of Fallot (11.8%). Mean hemoglobin level was 14.3 g/dL prior to surgery versus 12.1 g/dL at the PICU admission. Hemoglobin prior to surgery was systematically higher than hemoglobin at the PICU entry, except in infants with Hypoplastic Left Heart Syndrome. The average hemoglobin at PICU discharge was 11.7 ± 1.9 g/dL. Thirty-three (27.7%) patients were anemic at PICU discharge. Fifty-eight percent of patients received at least one red blood cell (RBC) transfusion during PICU stay. This study is the first to describe the epidemiology of anemia at PICU discharge in infants following cardiac surgery. Blood management of this distinctive and vulnerable population requires further investigation as anemia is a known risk factor for adverse neurodevelopment delays in otherwise healthy young children.

Defining postoperative transfusion thresholds in liver transplant recipients: A novel retrospective approach.

The optimal transfusion threshold for most patient populations has been defined as hematocrit (HCT) <21%. However, some specific patient populations are known to benefit from higher transfusion thresholds. To date, the optimal postoperative transfusion threshold for patients undergoing liver transplant has not been determined. To define the ideal transfusion threshold for liver transplant patients, we designed a retrospective study of 496 liver transplant recipients. Using HCT prior to discharge as a surrogate marker for transfusion thresholds we grouped patients into three groups of transfusion thresholds (HCT <21%, <24%, and >30%). Transfusion rates (intra- and postoperative), graft and patient survival, and complications requiring readmission were compared between groups. Ninety-two percent of patients were transfused during their hospital stay. Graft survival, patient survival, and rates of readmission within 30 days of discharge were no different between the three discharge HCT groups. Patients discharged with HCT >30% were less likely to be readmitted with infectious complications; however, this group also had the lowest model of end-stage liver (MELD) score at time of transplantation and were less likely to have received a transfusion during their hospital stay. Transfusion thresholds of HCT <24%, and potentially as low as 21% are acceptable in postoperative liver transplant recipients. The conduct of a randomized clinical trial, as supported by these data, will be necessary to support the use of lower thresholds.

The effect of blood transfusion on outcomes among African children admitted to hospital with Plasmodium falciparum malaria: a prospective, multicentre observational study

Infection with Plasmodium falciparum leads to severe malaria and death in approximately 400 000 children each year in sub-Saharan Africa. Blood transfusion might benefit some patients with malaria but could potentially harm others. The aim of this study was to estimate the association between transfusion and death among children admitted to hospital with P falciparum malaria. In this prospective, multicentre observational study, we analysed admissions to six tertiary care hospitals in The Gambia, Malawi, Gabon, Kenya, and Ghana that participated in the Severe Malaria in African Children network. Patients were enrolled if they were younger than 180 months and had a Giemsa-stained thick blood smear that was positive for P falciparum. Blood transfusion (whole blood at a target volume of 20 mL per kg) was administered at the discretion of the responsible physicians who were aware of local and international transfusion guidelines. The primary endpoint was death associated with transfusion, which was estimated using models adjusted for site and disease severity. We also aimed to identify factors associated with the decision to transfuse. The exploratory objective was to estimate optimal haemoglobin transfusion thresholds using generalised additive models. Between Dec 19, 2000, and March 8, 2005, 26 106 patients were enrolled in the study, 25 893 of whom had their transfusion status recorded and were included in the primary analysis. 8513 (32·8%) patients received a blood transfusion. Patients were followed-up until discharge from hospital for a median of 2 days (IQR 1-4). 405 (4·8%) of 8513 patients who received a transfusion died compared with 689 (4·0%) of 17 380 patients who did not receive a transfusion. Transfusion was associated with decreased odds of death in site-adjusted analysis (odds ratio [OR] 0·82 [95% CI 0·71-0·94]) and after adjusting for the increased disease severity of patients who received a transfusion (0·50 [0·42-0·60]). Severe anaemia, elevated lactate concentration, respiratory distress, and parasite density were associated with greater odds of receiving a transfusion. Among all study participants, transfusion was associated with improved survival when the admission haemoglobin concentration was up to 77 g/L (95% CI 65-110). Among those with impaired consciousness (Blantyre Coma Score ≤4), transfusion was associated with improved survival at haemoglobin concentrations up to 105 g/L (95% CI 71-115). Among those with hyperlactataemia (blood lactate ≥5·0 mmol/L), transfusion was not significantly associated with harm at any haemoglobin concentration-ie, the OR of death comparing transfused versus not transfused was less than 1 at all haemoglobin concentrations (lower bound of the 95% CI for the haemoglobin concentration at which the OR of death equals 1: 90 g/L; no upper bound). Our findings suggest that whole blood transfusion was associated with improved survival among children hospitalised with P falciparum malaria. Among those with impaired consciousness or hyperlactataemia, transfusion was associated with improved survival at haemoglobin concentrations above the currently recommended transfusion threshold. These findings highlight the need to do randomised controlled trials to test higher transfusion thresholds among African children with severe malaria complicated by these factors. US National Institute of Allergy and Infectious Diseases.

Effect of Perioperative Blood Transfusion in Anemic Patients Undergoing Infrainguinal Bypass

Patients who present with lower extremity ischemia are frequently anemic, and the optimal transfusion threshold for this cohort has remained controversial. We sought to evaluate the effect of blood transfusion on major adverse cardiac events (MACE), including myocardial infarction, dysrhythmia, stroke, congestive heart failure, and 30-day mortality for these patients. All consecutive patients who had undergone infrainguinal bypass at our institution from 2011 to 2020 were included. The primary outcome was MACE, and blood transfusion was the primary exposure. Univariate and multivariable analyses were performed to assess the effects of patient and procedural variables, including red blood cell transfusion, stratified by hemoglobin (Hb) nadir (<7, 7-8, >8 g/dL). Of the 287 patients reviewed for analysis, 146 (50.9%) had required transfusion (mean, 1.6 ± 3 U). The patients who had received a transfusion had had a mean nadir Hb of 8.3 ± 1.0 g/dL compared with 10.1 ± 1.7 g/dL for those without transfusion. The overall incidence of MACE was 15.7% (45 of 287 patients). Univariate analysis demonstrated that MACE was associated with blood transfusion (P = .009), lower Hb nadir (P = .02), higher blood loss (P = .003), higher baseline creatinine (P = .02), previous coronary revascularization (P = .002), nonambulatory status (P = .03), American Society of Anesthesiologists classification 4 or 5 (P < .0001), and preoperative P2Y12 antagonist therapy (P = .049). Transfusion was independently associated with MACE for patients with a Hb nadir >8 (odds ratio [OR], 3.09; P = .006) but not for patients with a Hb nadir of 7 to 8 (OR, 0.818; P = .77). The effect in the Hb nadir <7 group was inconclusive (Fig). The only other variables independently associated with MACE were previous coronary revascularization (OR, 2.58; P = .01) and higher blood loss (OR, 1.05; P = .02). The hospital length of stay for patients with MACE was significantly longer than that for patients without MACE (14.8 vs 8.2 days; P < .001). For patients undergoing infrainguinal bypass, receiving a transfusion with a Hb nadir >8 was associated with a threefold increase in MACE, with a length of stay twice as long. For patients with a Hb of 7 to 8, transfusion did not increase or reduce the incidence of MACE. These findings suggest no benefit of blood transfusions for patients with a Hb nadir >7 and harm for those with a Hb nadir >8.

Platelet Count and Function during Pediatric Extracorporeal Membrane Oxygenation.

Extracorporeal membrane oxygenation (ECMO) is a form of life support used to treat neonates, children, and adults with cardiorespiratory failure refractory to conventional therapy. This therapy requires the use of anticoagulation to prevent clotting in the extracorporeal circuit, but anticoagulation also increases the risk of bleeding on ECMO. Both bleeding and thrombosis remain significant complications on ECMO and balancing these risks is challenging. Acquired platelet dysfunction is common during ECMO and quantitative and qualitative platelet dysfunction contributes to bleeding risk. Optimal platelet count, function, and transfusion thresholds are not well established during pediatric ECMO. In this review, we provide an overview of hemostatic alterations during ECMO, changes in platelet count and function, platelet monitoring techniques, bleeding risk, and future needs to best optimize patient management and care.

Transfusion, mortality and hemoglobin level: Associations among emergency department patients in Kigali, Rwanda.

BackgroundStudies from high-income countries (HIC) support restrictive blood transfusion thresholds in medical patients. In low- and middle-income countries (LMIC), the etiologies of anemia and baseline health states differ greatly; optimal transfusion thresholds are unknown. This study evaluated the association of packed red blood cell (PRBC) transfusion with mortality outcomes across hemoglobin levels amongst emergency center (EC) patients presenting with medical pathology in Kigali, Rwanda.MethodsThis retrospective cohort study was performed using a random sample of patients presenting to the EC at the University Teaching Hospital of Kigali. Patients ≥15 years of age, treated for medical emergencies during 2013–16, with EC hemoglobin measurements were included. The relationship between EC PRBC transfusion and patient mortality was evaluated using logistic regression, with stratified analyses performed at hemoglobin levels of 7 mg/dL and 5 mg/dL.ResultsOf 3609 cases sampled, 1116 met inclusion. The median age was 42 years (IQR 29, 60) and 45.2% were female. Transfusion occurred in 12.1% of patients. Hematologic (24.4%) and gastrointestinal pathologies (20.7%) were the primary diagnoses of those transfused. Proportional mortality was higher amongst those receiving transfusions, although not statistically significant (23.7% vs 17.0%, p = 0.06). No significant difference in adjusted odds of overall mortality by PRBC transfusion was found. In stratified analysis, patients receiving EC transfusions with a hemoglobin >5.0 mg/dL, had 2.21 times the odds of mortality (95% CI 1.51–3.21) as compared to those ≤5.0 mg/dL.ConclusionsNo association between PRBC transfusion and odds of mortality was observed amongst EC patients in this LMIC setting. An increased mortality association was found for patients receiving PRBC transfusions with an initial hemoglobin >5 mg/dL. Results suggest benefits from PRBC transfusion are limited as compared to HIC. Further research evaluating emergent transfusion thresholds for medical pathologies should be performed in LMICs to guide practice.

Management of anaemia in pre-term infants.

Pre-term infants have one of the highest transfusion requirements within the hospital-setting. The vast majority of blood transfusions performed in Neonatal Intensive Care Units (NICUs) are for medically stable pre-term infants with anaemia of prematurity, with the aim of improving oxygen delivery to the vital organs during the crucial phase of growth and development. However, despite the frequency of transfusion in this population, the potential benefits and harms of 'top up' transfusion are not fully understood, leading to practice variation between clinicians, institutions and countries. Significant advances have been made in the prevention of anaemia of prematurity, with recent emphasis on optimising infants' circulatory volume at birth via placental transfusion and preserving infants' own blood volume through innovative minimal sampling techniques. More research is urgently needed to establish optimal transfusion thresholds for these high-risk pre-term infants, for whom benefits as well as adverse outcomes may have consequences that extend for decades throughout the recipients' life-course. In this review, we will discuss some of the consensus and controversies regarding optimal management of anaemia in pre-term infants and highlight potential areas for future research.

Red blood cell transfusion in critically ill patients with traumatic brain injury: an international survey of physicians' attitudes.

Restrictive transfusion strategies have been advocated in critically ill patients. Nevertheless, considerable uncertainty exists regarding optimal transfusion thresholds in traumatic brain injury (TBI) patients because the injured brain is susceptible to hypoxemic damage. We aimed to identify the determinants of red blood cell (RBC) transfusion and the perceived optimal transfusion thresholds in adult patients with moderate-to-severe TBI. We conducted an electronic, self-administered survey targeting critical care specialists and neurosurgeons from Canada, Australia, and the United Kingdom caring for TBI patients. The questionnaire was initially developed by a panel of experts using a structured process (domains/items generation and reduction). The questionnaire was validated for clinical sensibility, reliability, and content. The response rate was 28.7% (218/760). When presented with the hypothetical scenario of a young adult TBI patient, a wide range of transfusion practices was observed, with 47 (95% confidence interval [CI], 41 to 54)% favouring RBC transfusion at a hemoglobin level of ≤ 70 g·L-1 in the acute phase of care, while 73 (95% CI, 67 to 79)% would use this trigger in the plateau phase of care. Multiple trauma, neuro-monitoring data, hemorrhagic shock, and planned surgery were the main factors that influenced the need for transfusion. The lack of clinical evidence and guidelines was responsible for uncertainty regarding RBC transfusion strategies in this patient population. In our survey about critically ill TBI patients, transfusion practice was found to be mainly influenced by the acuity of care, patient characteristics, and neuro-monitoring. Clinical equipoise regarding optimal transfusion strategy is believed to be mainly attributed to the lack of clear clinical evidence and guidelines. Appropriate randomized-controlled trials are required to determine the optimal transfusion strategies in TBI patients.