Where do all the red blood cells (RBCs) go? Results of a survey of RBC use in England and North Wales in 2014

Restrictive versus liberal red blood cell transfusion strategies for people with haematological malignancies treated with intensive chemotherapy or radiotherapy, or both, with or without haematopoietic stem cell support

BACKGROUND

An estimated one-quarter to one-half of people diagnosed with haematological malignancies experience anaemia. There are different strategies for red blood cell (RBC) transfusions to treat anaemia. A restrictive transfusion strategy permits a lower haemoglobin (Hb) level whereas a liberal transfusion strategy aims to maintain a higher Hb. The most effective and safest strategy is unknown.

OBJECTIVES

To determine the efficacy and safety of restrictive versus liberal RBC transfusion strategies for people diagnosed with haematological malignancies treated with intensive chemotherapy or radiotherapy, or both, with or without a haematopoietic stem cell transplant (HSCT).

SEARCH METHODS

We searched for randomised controlled trials (RCTs) and non-randomised studies (NRS) in MEDLINE (from 1946), Embase (from 1974), CINAHL (from 1982), Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2023, Issue 2), and eight other databases (including three trial registries) to 21 March 2023. We also searched grey literature and contacted experts in transfusion for additional trials. There were no language, date or publication status restrictions.

SELECTION CRITERIA

We included RCTs and prospective NRS that evaluated restrictive versus liberal RBC transfusion strategies in children or adults with malignant haematological disorders receiving intensive chemotherapy or radiotherapy, or both, with or without HSCT.

DATA COLLECTION AND ANALYSIS

Two authors independently screened references, full-text reports of potentially relevant studies, extracted data from the studies, and assessed the risk of bias. Any disagreement was discussed and resolved with a third review author. Dichotomous outcomes were presented as a risk ratio (RR) with a 95% confidence interval (CI). Narrative syntheses were used for heterogeneous outcome measures. Review Manager Web was used to meta-analyse the data. Main outcomes of interest included: all-cause mortality at 31 to 100 days, quality of life, number of participants with any bleeding, number of participants with clinically significant bleeding, serious infections, length of hospital admission (days) and hospital readmission at 0 to 3 months. The certainty of the evidence was assessed using GRADE.

MAIN RESULTS

Nine studies met eligibility; eight RCTs and one NRS. Six hundred and forty-four participants were included from six completed RCTs (n = 560) and one completed NRS (n = 84), with two ongoing RCTs consisting of 294 participants (260 adult and 34 paediatric) pending inclusion. Only one completed RCT included children receiving HSCT (n = 6); the other five RCTs only included adults: 239 with acute leukaemia receiving chemotherapy and 315 receiving HSCT (166 allogeneic and 149 autologous). The transfusion threshold ranged from 70 g/L to 80 g/L for restrictive and from 80 g/L to 120 g/L for liberal strategies. Effects were reported in the summary of findings tables only for the trials that included adults to reduce indirectness due to the limited evidence contributed by the prematurely terminated paediatric trial. Evidence from RCTs Overall, there may be little to no difference in the number of participants who die within 31 to 100 days using a restrictive compared to a liberal transfusion strategy, but the evidence is very uncertain (three studies; 451 participants; RR 1.00, 95% CI 0.27 to 3.70, P=0.99; very low-certainty evidence). There may be little to no difference in quality of life at 0 to 3 months using a restrictive compared to a liberal transfusion strategy, but the evidence is very uncertain (three studies; 431 participants; analysis unable to be completed due to heterogeneity; very low-certainty evidence). There may be little to no difference in the number of participants who suffer from any bleeding at 0 to 3 months using a restrictive compared to a liberal transfusion strategy (three studies; 448 participants; RR 0.91, 95% CI 0.78 to 1.06, P = 0.22; low-certainty evidence). There may be little to no difference in the number of participants who suffer from clinically significant bleeding at 0 to 3 months using a restrictive compared to a liberal transfusion strategy (four studies; 511 participants; RR: 0.94, 95% CI 0.74 to 1.19, P = 0.60; low-certainty evidence). There may be little to no difference in the number of participants who experience serious infections at 0 to 3 months using a restrictive compared to a liberal transfusion strategy (three studies, 451 participants; RR: 1.20, 95% CI 0.93 to 1.55, P = 0.17; low-certainty evidence). A restrictive transfusion strategy likely results in little to no difference in the length of hospital admission at 0 to 3 months compared to a liberal strategy (two studies; 388 participants; analysis unable to be completed due to heterogeneity in reporting; moderate-certainty evidence). There may be little to no difference between hospital readmission using a restrictive transfusion strategy compared to a liberal transfusion strategy (one study, 299 participants; RR: 0.89, 95% CI 0.52 to 1.50; P = 0.65; low-certainty evidence). Evidence from NRS The evidence is very uncertain whether a restrictive RBC transfusion strategy: reduces the risk of death within 100 days (one study, 84 participants, restrictive 1 death; liberal 1 death; very low-certainty evidence); or decreases the risk of clinically significant bleeding (one study, 84 participants, restrictive 3; liberal 8; very low-certainty evidence). No NRS reported on the other eligible outcomes.

AUTHORS' CONCLUSIONS

Findings from this review were based on seven studies and 644 participants. Definite conclusions are challenging given the relatively few included studies, low number of included participants, heterogeneity of intervention and outcome reporting, and overall certainty of evidence. To increase the certainty of the true effect of a restrictive RBC transfusion strategy on clinical outcomes, there is a need for rigorously designed and executed studies. The evidence is largely based on two populations: adults with acute leukaemia receiving intensive chemotherapy and adults with haematologic malignancy requiring HSCT. Despite the addition of 405 participants from three RCTs to the previous review's results, there is still insufficient evidence to answer this review's primary outcome. If we assume a mortality rate of 3% within 100 days, we would need a total of 1492 participants to have an 80% chance of detecting, at a 5% level of significance, an increase in all-cause mortality from 3% to 6%. Further RCTs are needed overall, particularly in children.

Pharmacological interventions for the prevention of bleeding in people undergoing elective hip or knee surgery: a systematic review and network meta-analysis

BACKGROUND

Hip and knee replacement surgery is a well-established means of improving quality of life, but is associated with a significant risk of bleeding. One-third of people are estimated to be anaemic before hip or knee replacement surgery; coupled with the blood lost during surgery, up to 90% of individuals are anaemic postoperatively. As a result, people undergoing orthopaedic surgery receive 3.9% of all packed red blood cell transfusions in the UK. Bleeding and the need for allogeneic blood transfusions has been shown to increase the risk of surgical site infection and mortality, and is associated with an increased duration of hospital stay and costs associated with surgery. Reducing blood loss during surgery may reduce the risk of allogeneic blood transfusion, reduce costs and improve outcomes following surgery. Several pharmacological interventions are available and currently employed as part of routine clinical care.

OBJECTIVES

To determine the relative efficacy of pharmacological interventions for preventing blood loss in elective primary or revision hip or knee replacement, and to identify optimal administration of interventions regarding timing, dose and route, using network meta-analysis (NMA) methodology.

SEARCH METHODS

We searched the following databases for randomised controlled trials (RCTs) and systematic reviews, from inception to 18 October 2022: CENTRAL (the Cochrane Library), MEDLINE (Ovid), Embase (Ovid), CINAHL (EBSCOhost), Transfusion Evidence Library (Evidentia), ClinicalTrials.gov and WHO International Clinical Trials Registry Platform (ICTRP).

SELECTION CRITERIA

We included RCTs of people undergoing elective hip or knee surgery only. We excluded non-elective or emergency procedures, and studies published since 2010 that had not been prospectively registered (Cochrane Injuries policy). There were no restrictions on gender, ethnicity or age (adults only). We excluded studies that used standard of care as the comparator. Eligible interventions included: antifibrinolytics (tranexamic acid (TXA), aprotinin, epsilon-aminocaproic acid (EACA)), desmopressin, factor VIIa and XIII, fibrinogen, fibrin sealants and non-fibrin sealants.

DATA COLLECTION AND ANALYSIS

We performed the review according to standard Cochrane methodology. Two authors independently assessed trial eligibility and risk of bias, and extracted data. We assessed the certainty of the evidence using CINeMA. We presented direct (pairwise) results using RevMan Web and performed the NMA using BUGSnet. We were interested in the following primary outcomes: need for allogenic blood transfusion (up to 30 days) and all-cause mortality (deaths occurring up to 30 days after the operation), and the following secondary outcomes: mean number of transfusion episodes per person (up to 30 days), re-operation due to bleeding (within seven days), length of hospital stay and adverse events related to the intervention received.

MAIN RESULTS

We included a total of 102 studies. Twelve studies did not report the number of included participants; the other 90 studies included 8418 participants. Trials included more women (64%) than men (36%). In the NMA for allogeneic blood transfusion, we included 47 studies (4398 participants). Most studies examined TXA (58 arms, 56%). We found that TXA, given intra-articularly and orally at a total dose of greater than 3 g pre-incision, intraoperatively and postoperatively, ranked the highest, with an anticipated absolute effect of 147 fewer blood transfusions per 1000 people (150 fewer to 104 fewer) (53% chance of ranking 1st) within the NMA (risk ratio (RR) 0.02, 95% credible interval (CrI) 0 to 0.31; moderate-certainty evidence). This was followed by TXA given orally at a total dose of 3 g pre-incision and postoperatively (RR 0.06, 95% CrI 0.00 to 1.34; low-certainty evidence) and TXA given intravenously and orally at a total dose of greater than 3 g intraoperatively and postoperatively (RR 0.10, 95% CrI 0.02 to 0.55; low-certainty evidence). Aprotinin (RR 0.59, 95% CrI 0.36 to 0.96; low-certainty evidence), topical fibrin (RR 0.86, CrI 0.25 to 2.93; very low-certainty evidence) and EACA (RR 0.60, 95% CrI 0.29 to 1.27; very low-certainty evidence) were not shown to be as effective compared with TXA at reducing the risk of blood transfusion. We were unable to perform an NMA for our primary outcome all-cause mortality within 30 days of surgery due to the large number of studies with zero events, or because the outcome was not reported. In the NMA for deep vein thrombosis (DVT), we included 19 studies (2395 participants). Most studies examined TXA (27 arms, 64%). No studies assessed desmopressin, EACA or topical fibrin. We found that TXA given intravenously and orally at a total dose of greater than 3 g intraoperatively and postoperatively ranked the highest, with an anticipated absolute effect of 67 fewer DVTs per 1000 people (67 fewer to 34 more) (26% chance of ranking first) within the NMA (RR 0.16, 95% CrI 0.02 to 1.43; low-certainty evidence). This was followed by TXA given intravenously and intra-articularly at a total dose of 2 g pre-incision and intraoperatively (RR 0.21, 95% CrI 0.00 to 9.12; low-certainty evidence) and TXA given intravenously and intra-articularly, total dose greater than 3 g pre-incision, intraoperatively and postoperatively (RR 0.13, 95% CrI 0.01 to 3.11; low-certainty evidence). Aprotinin was not shown to be as effective compared with TXA (RR 0.67, 95% CrI 0.28 to 1.62; very low-certainty evidence). We were unable to perform an NMA for our secondary outcomes pulmonary embolism, myocardial infarction and CVA (stroke) within 30 days, mean number of transfusion episodes per person (up to 30 days), re-operation due to bleeding (within seven days), or length of hospital stay, due to the large number of studies with zero events, or because the outcome was not reported by enough studies to build a network. There are 30 ongoing trials planning to recruit 3776 participants, the majority examining TXA (26 trials).

AUTHORS' CONCLUSIONS

We found that of all the interventions studied, TXA is probably the most effective intervention for preventing bleeding in people undergoing hip or knee replacement surgery. Aprotinin and EACA may not be as effective as TXA at preventing the need for allogeneic blood transfusion. We were not able to draw strong conclusions on the optimal dose, route and timing of administration of TXA. We found that TXA given at higher doses tended to rank higher in the treatment hierarchy, and we also found that it may be more beneficial to use a mixed route of administration (oral and intra-articular, oral and intravenous, or intravenous and intra-articular). Oral administration may be as effective as intravenous administration of TXA. We found little to no evidence of harm associated with higher doses of tranexamic acid in the risk of DVT. However, we are not able to definitively draw these conclusions based on the trials included within this review.

Comparing transfusion practice at multiple hospitals using electronically collected and analysed data

BACKGROUND

Comparisons of transfusion practice between organisations are time-consuming using manual methods for data collection. We performed a feasibility study to determine whether large-scale transfusion data from three English hospitals could be combined to allow comparisons of transfusion practice.

METHODS

Clinical, laboratory and transfusion data from patients discharged between 1 April 2016 and 31 March 2017 were extracted from Patient Administration Systems (PAS), Laboratory Information Management Systems (LIMS), and electronic transfusion systems at three NHS hospitals, which are academic medical centres based in large cities outside London. A centralised database and business intelligence software were used to compare the data.

RESULTS

The dataset contained 748 982 episodes of patient care with 91 410 blood components transfused. The study confirms the results of previous studies finding peaks in the ages of transfusion in the 0-4 years age range, in women of childbearing ages, and in males over 60 years. The number of components transfused per 1000 bed days was used as a standardised comparator. Red cell utilisation was 42.4, 40.4 and 49.5 units/1000 bed days and platelet utilisation 11.69, 7.76, and 11.66 units/1000 bed days. 60.5% (6848/11 310) of Group O D negative red cell units were transfused to non-group O D negative recipients. An analysis of component usage highlighted variations in practice, for example platelet usage for cardiac surgery varied from 2.4% to 7.3% across the three hospitals.

CONCLUSION

This feasibility study demonstrates that large electronic datasets from hospitals can be combined to identify areas for targeted interventions to improve transfusion practice.

There is an urgent need to adopt a pull-flow logic for the supply of RBCs to meet patients' needs: A single center study

BACKGROUND

Despite major demographic changes, several decisions and initiatives, among which Patient Blood Management, have led to a significant reduction in the transfusion of packed red blood cells (RBCs) in Belgium, as it has been observed in many countries. Unfortunately, not all blood groups were proportionately impacted and shortage in O D-negative RBCs is regularly or chronically observed. The goal of this study was to examine how to optimize the use and the supply of O D-negative blood in our academic hospital.

METHODOLOGY

All blood transfusions performed at Cliniques universitaires Saint-Luc between January 1, 2019 and December 31, 2021 were reviewed. The blood group of the patients was compared with the blood group of the RBCs actually supplied and transfused.

RESULTS

49.823 RBCs transfusions were analyzed. The patients' needs didn't reflect those of a Caucasian population, with an increase of O (47.9%) and B (10.3%) for the ABO blood group, and a quite high proportion of R0r (8.6%) for the Rh blood group. Only two thirds of O D-negative RBCs were transfused to O rr or R0r patients.

CONCLUSION

The application of PBM and the ethnic imbalance between blood donor and patient populations are two important risk factors for chronic shortages of O D-negative blood. To adapt blood component resources, it is essential to have a complete picture of the real needs of patients according to their blood group profile. Blood donor centers must adapt to the evolving needs of hospitals in order to plan future supplies in a "pull-flow" approach.

Cell salvage for minimising perioperative allogeneic blood transfusion in adults undergoing elective surgery

BACKGROUND

Concerns regarding the safety and availability of transfused donor blood have prompted research into a range of techniques to minimise allogeneic transfusion requirements. Cell salvage (CS) describes the recovery of blood from the surgical field, either during or after surgery, for reinfusion back to the patient.

OBJECTIVES

To examine the effectiveness of CS in minimising perioperative allogeneic red blood cell transfusion and on other clinical outcomes in adults undergoing elective or non-urgent surgery.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, three other databases and two clinical trials registers for randomised controlled trials (RCTs) and systematic reviews from 2009 (date of previous search) to 19 January 2023, without restrictions on language or publication status.

SELECTION CRITERIA

We included RCTs assessing the use of CS compared to no CS in adults (participants aged 18 or over, or using the study's definition of adult) undergoing elective (non-urgent) surgery only.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included 106 RCTs, incorporating data from 14,528 participants, reported in studies conducted in 24 countries. Results were published between 1978 and 2021. We analysed all data according to a single comparison: CS versus no CS. We separated analyses by type of surgery. The certainty of the evidence varied from very low certainty to high certainty. Reasons for downgrading the certainty included imprecision (small sample sizes below the optimal information size required to detect a difference, and wide confidence intervals), inconsistency (high statistical heterogeneity), and risk of bias (high risk from domains including sequence generation, blinding, and baseline imbalances). Aggregate analysis (all surgeries combined: primary outcome only) Very low-certainty evidence means we are uncertain if there is a reduction in the risk of allogeneic transfusion with CS (risk ratio (RR) 0.65, 95% confidence interval (CI) 0.59 to 0.72; 82 RCTs, 12,520 participants). Cancer: 2 RCTs (79 participants) Very low-certainty evidence means we are uncertain whether there is a difference for mortality, blood loss, infection, or deep vein thrombosis (DVT). There were no analysable data reported for the remaining outcomes. Cardiovascular (vascular): 6 RCTs (384 participants) Very low- to low-certainty evidence means we are uncertain whether there is a difference for most outcomes. No data were reported for major adverse cardiovascular events (MACE). Cardiovascular (no bypass): 6 RCTs (372 participants) Moderate-certainty evidence suggests there is probably a reduction in risk of allogeneic transfusion with CS (RR 0.82, 95% CI 0.69 to 0.97; 3 RCTs, 169 participants). Very low- to low-certainty evidence means we are uncertain whether there is a difference for volume transfused, blood loss, mortality, re-operation for bleeding, infection, wound complication, myocardial infarction (MI), stroke, and hospital length of stay (LOS). There were no analysable data reported for thrombosis, DVT, pulmonary embolism (PE), and MACE. Cardiovascular (with bypass): 29 RCTs (2936 participants) Low-certainty evidence suggests there may be a reduction in the risk of allogeneic transfusion with CS, and suggests there may be no difference in risk of infection and hospital LOS. Very low- to moderate-certainty evidence means we are uncertain whether there is a reduction in volume transfused because of CS, or if there is any difference for mortality, blood loss, re-operation for bleeding, wound complication, thrombosis, DVT, PE, MACE, and MI, and probably no difference in risk of stroke. Obstetrics: 1 RCT (1356 participants) High-certainty evidence shows there is no difference between groups for mean volume of allogeneic blood transfused (mean difference (MD) -0.02 units, 95% CI -0.08 to 0.04; 1 RCT, 1349 participants). Low-certainty evidence suggests there may be no difference for risk of allogeneic transfusion. There were no analysable data reported for the remaining outcomes. Orthopaedic (hip only): 17 RCTs (2055 participants) Very low-certainty evidence means we are uncertain if CS reduces the risk of allogeneic transfusion, and the volume transfused, or if there is any difference between groups for mortality, blood loss, re-operation for bleeding, infection, wound complication, prosthetic joint infection (PJI), thrombosis, DVT, PE, stroke, and hospital LOS. There were no analysable data reported for MACE and MI. Orthopaedic (knee only): 26 RCTs (2568 participants) Very low- to low-certainty evidence means we are uncertain if CS reduces the risk of allogeneic transfusion, and the volume transfused, and whether there is a difference for blood loss, re-operation for bleeding, infection, wound complication, PJI, DVT, PE, MI, MACE, stroke, and hospital LOS. There were no analysable data reported for mortality and thrombosis. Orthopaedic (spine only): 6 RCTs (404 participants) Moderate-certainty evidence suggests there is probably a reduction in the need for allogeneic transfusion with CS (RR 0.44, 95% CI 0.31 to 0.63; 3 RCTs, 194 participants). Very low- to moderate-certainty evidence suggests there may be no difference for volume transfused, blood loss, infection, wound complication, and PE. There were no analysable data reported for mortality, re-operation for bleeding, PJI, thrombosis, DVT, MACE, MI, stroke, and hospital LOS. Orthopaedic (mixed): 14 RCTs (4374 participants) Very low- to low-certainty evidence means we are uncertain if there is a reduction in the need for allogeneic transfusion with CS, or if there is any difference between groups for volume transfused, mortality, blood loss, infection, wound complication, PJI, thrombosis, DVT, MI, and hospital LOS. There were no analysable data reported for re-operation for bleeding, MACE, and stroke.

AUTHORS' CONCLUSIONS

In some types of elective surgery, cell salvage may reduce the need for and volume of allogeneic transfusion, alongside evidence of no difference in adverse events, when compared to no cell salvage. Further research is required to establish why other surgeries show no benefit from CS, through further analysis of the current evidence. More large RCTs in under-reported specialities are needed to expand the evidence base for exploring the impact of CS.

Treatment Strategies in Anemic Patients Before Cardiac Surgery

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

Real world reduction in red cell transfusion with restrictive transfusion threshold in haematology inpatients

OBJECTIVES

The aim of this study was to assess the reduction in red cell transfusions following a change in the red cell transfusion threshold for haematology inpatients from 80 to 70 g/L.

BACKGROUND

Haematology patients are among the high users of red blood cells. We reduced the threshold for transfusion of haematology inpatients to 70 g/L. This was based on evidence provided by randomised controlled trial published in 2020 that showed restrictive transfusion is non-inferior to liberal transfusion.

METHOD

We assessed red cell transfusions for haematology inpatients at Oxford University Hospitals NHS Foundation Trust for 9 months before and 9 months after a change in red cell transfusion threshold from 80 to 70 g/L.

RESULTS

After the change in threshold to 70 g/L or less from 80 g/L, the median number of red cell transfusions per month reduced to 88 from 111. This was a 23% reduction in the total number of red cells administered per month.

CONCLUSION

These results show the real-world reductions in transfusion that can be made by putting local transfusion guidelines in line with the international recommendations. This is of particular importance at a time of national blood shortage.

Fibrinogen, Coagulation, and Ageing

The World Health Organization estimates that the world's population over 60 years of age will nearly double in the next 30 years. This change imposes increasing demands on health and social services with increased disease burden in older people, hereafter defined as people aged 60 years or more. An older population will have a greater incidence of cardiovascular disease partly due to higher levels of blood fibrinogen, increased levels of some coagulation factors, and increased platelet activity. These factors lead to a hypercoagulable state which can alter haemostasis, causing an imbalance in appropriate coagulation, which plays a crucial role in the development of cardiovascular diseases. These changes in haemostasis are not only affected by age but also by gender and the effects of hormones, or lack thereof in menopause for older females, ethnicity, other comorbidities, medication interactions, and overall health as we age. Another confounding factor is how we measure fibrinogen and coagulation through laboratory and point-of-care testing and how our decision-making on disease and treatment (including anticoagulation) is managed. It is known throughout life that in normal healthy individuals the levels of fibrinogen and coagulation factors change, however, reference intervals to guide diagnosis and management are based on only two life stages, paediatric, and adult ranges. There are no specific diagnostic guidelines based on reference intervals for an older population. How ageing relates to alterations in haemostasis and the impact of the disease will be discussed in this chapter. Along with the effect of anticoagulation, laboratory testing of fibrinogen and coagulation, future directions, and implications will be presented.

Prehabilitation of Cardiac Surgical Patients, Part 1: Anemia, Diabetes Mellitus, Obesity, Sleep Apnea, and Cardiac Rehabilitation

The concept of "prehabilitation" consists of screening for and identification of pre-existing disorders followed by medical optimization. This is performed for many types of surgery, but may have profound impacts on outcomes particularly in cardiac surgery given the multiple comorbidities typically carried by these patients. Components of prehabilitation include direct medical intervention by preoperative specialists as well as significant care coordination and shared decision making. In this two-part review, the authors describe existing evidence to support the optimization of various preoperative problems and present a few institutional protocols utilized by our center for cardiac presurgical care. This first installment will focus on the management of anemia, obesity, sleep apnea, diabetes, and cardiac rehabilitation prior to surgery. The second will focus on frailty, malnutrition, respiratory disease, alcohol and smoking cessation, and depression.

Prediction of Red Blood Cell Demand for Pediatric Patients Using a Time-Series Model: A Single-Center Study in China

Background

Red blood cells (RBCs) are an essential factor to consider for modern medicine, but planning the future collection of RBCs and supply efforts for coping with fluctuating demands is still a major challenge.

Objectives

This study aimed to explore the feasibility of the time-series model in predicting the clinical demand of RBCs for pediatric patients each month.

Methods

Our study collected clinical RBC transfusion data from years 2014 to 2019 in the National Center for Children's Health (Beijing) in China, with the goal of constructing a time-series, autoregressive integrated moving average (ARIMA) model by fitting the monthly usage of RBCs from 2014 to 2018. Furthermore, the optimal model was used to forecast the monthly usage of RBCs in 2019, and we subsequently compared the data with actual values to verify the validity of the model.

Results

The seasonal multiplicative model SARIMA (0, 1, 1) (1, 1, 0)₁₂ (normalized BIC = 8.740, R² = 0.730) was the best prediction model and could better fit and predict the monthly usage of RBCs for pediatric patients in this medical center in 2019. The model residual sequence was white noise (Ljung-Box Q₍₁₈₎ = 15.127, P > 0.05), and its autocorrelation function (ACF) and partial autocorrelation function (PACF) coefficients also fell within the 95% confidence intervals (CIs). The parameter test results were statistically significant (P < 0.05). 91.67% of the actual values were within the 95% CIs of the forecasted values of the model, and the average relative error of the forecasted and actual values was 6.44%, within 10%.

Conclusions

The SARIMA model can simulate the changing trend in monthly usage of RBCs of pediatric patients in a time-series aspect, which represents a short-term prediction model with high accuracy. The continuously revised SARIMA model may better serve the clinical environments and aid with planning for RBC demand. A clinical study including more data on blood use should be conducted in the future to confirm these results.

Optimierung der Depotführung für Erythrozytenkonzentrate in Krankenhäusern

Blutdepots ohne eigene Herstellung müssen Versorgungssicherheit garantieren, dabei aber auch eine möglichst geringe Verfallsrate sicherstellen. Für die Anzahl der zu bevorratenden Erythrozytenkonzentrate (EK) der verschiedenen Blutgruppen wird folgendes Berechnungsmodell gefunden: 1. Die örtliche Verteilung der AB0-Blutgruppen im Patientenkollektiv kann mit dem Hardy-Weinberg-Gesetz auf Plausibilität überprüft werden. 2. Der Beobachtungszeitraum ist die durchschnittliche Restlaufzeit von der Lieferung bis zum Ende der Haltbarkeit. 3. Der Erwartungswert für die Fallzahl transfundierter Patienten einer bestimmten Blutgruppe gehorcht einer Binomialverteilung. 4. Die Anzahl transfundierter Erythrozytenkonzentrate pro Patient ist geometrisch verteilt. 5. Eine Matrix wird gebildet, deren Zellen das Produkt aus Fallzahl (3.) und EK pro Fall (4.) und somit die Anzahl der benötigten EK enthalten. Nur letztgenannte sind für die Führung des Blutdepots interessant. Subtrahiert man die Zahl der im Beobachtungszeitraum (2.) benötigten EK von der Depotgröße, erhält man den Verfall. Der Vorrat von EK der Blutgruppe 0 bemisst sich an der maximal zu erwartenden Zahl benötigter Konserven für einen Fall bis zur nächstmöglichen Lieferung, wenn der durchschnittliche Depotumsatz diesen Wert nicht übersteigt. Er kann somit insbesondere in peripheren Krankenhäusern mit Akutversorgung die oben beschriebene Kalkulation deutlich überschreiten. Für Blutgruppe A gilt dieser Grundsatz nicht, wenn auch kompatible (0 auf A) Transfusionen stattfinden sollen. Binomial ist bei kleiner Anzahl nach links – das heißt gegen Null – schief verteilt. Dies betrifft in jedem Fall AB, bei jährlichem Depotumsatz unter ungefähr 1000 EK aber auch Blutgruppe B. Möchte man den Verfall vermeiden, darf man die betroffenen Blutgruppen nicht – zumindest nicht in dem notwendigen Umfang – bevorraten und muss dann majorkompatibel transfundieren. Die Unterschiede der einzelnen AB0-Blutgruppen in Herstellung (Blutgruppenverteilung in der Spenderpopulation) und der Bevorratung in Krankenhaus-Blutdepots sind hierin begründet. Entsprechende Überlegungen gelten gleichermaßen für den Rhesusfaktor D. Die oft emotional geführte Debatte über die zu bevorratende Anzahl an EK kann mittels dieses mathematischen Modells auf eine rationale Grundlage zurückgeführt werden. Das Rechenmodell ist mit einem einfachen Tabellenkalkulationsprogramm möglich. Das Blutdepot bestimmt damit den optimalen Bestand. Für die Blutspendedienste ergibt sich hieraus die Möglichkeit, die Kunden individuell, das heißt umsatzabhängig, zu beraten und gegebenenfalls den Preis entsprechend zu gestalten. Im Rahmen der Qualitätssicherung können abteilungs- oder krankenhausspezifische Besonderheiten im Transfusionsverhalten dargestellt werden.

Clinical practice for outpatients that are chronically red cell dependent: A survey in the Netherlands

BACKGROUND AND OBJECTIVES

Limited data are available to guide physicians on how to determine the red blood cell (RBC) transfusion regimen in chronically transfusion-dependent patients. The lack of clarity on thresholds and targets to be used for transfusion could easily result in either under or over transfusion in these patients. The aim of our survey is to investigate (1) transfusion thresholds; (2) number of RBC units given per transfusion episode; (3) interval between transfusions and (4) patient factors, like decreased cardiac function modulating the former.

MATERIALS AND METHODS

We sent a web-based 44-question survey to members of the Dutch Haematology Association.

RESULTS

Fifty physicians responded between June and October 2020 (response rate 30%), well-distributed between community and academic hospitals. A wide variation in transfusion strategies was reported: Most patients have transfused 1-2 RBC units (range: 0-3 units) every 2-4 weeks (range: 1-12 weeks) with a median threshold of 8.0 g/dl ranging from 6.4 to 9.6 g/dl. Patient-specific clinical factors that are most frequently reported to influence the transfusion strategy are angina pectoris, cardiac failure and dyspnoea, softer parameters that are of influence are the quality of life and self-sustainability.

CONCLUSION

The results of this survey indicate a broad variation in RBC transfusion strategies in Dutch patients with chronic transfusion dependency. While the current variation in transfusion strategies may be unavoidable in an individualized approach, randomized trials and better defined usable parameters to evaluate the effect of transfusion strategies are required to reach a consensus on how to determine the transfusion strategy.

Extended red blood cell matching for all transfusion recipients is feasible

OBJECTIVE

To demonstrate the feasibility and effectiveness of extended matching of red blood cells (RBC) in practice.

BACKGROUND

At present, alloimmunisation preventing matching strategies are only applied for specific transfusion recipient groups and include a limited number of RBC antigens. The general assumption is that providing fully matched RBC units to all transfusion recipients is not feasible. In this article we refute this assumption and compute the proportion of alloimmunisation that can be prevented, when all donors and transfusion recipients are typed for A, B, D plus twelve minor blood group antigens (C, c, E, e, K, Fy^a , Fy^b , Jk^a , Jk^b , M, S and s).

METHODS

We developed a mathematical model that determines the optimal sequence for antigen matching. The model allows for various matching strategies, issuing policies and inventory sizes.

RESULTS

For a dynamic inventory composition (accounting for randomness in the phenotypes supplied and requested) and an antigen identical issuing policy 97% and 94% of alloimmunisation events can be prevented, when respectively one and two RBC units per recipient are requested from an inventory of 1000 units. Although this proportion decreases with smaller inventory sizes, even for an inventory of 60 units almost 50% of all alloimmunisation events can be prevented.

CONCLUSION

In case antigen of both donors and recipients are comprehensively typed, extended preventive matching is feasible for all transfusion recipients in practice and will significantly reduce transfusion-induced alloimmunisation and (alloantibody-induced) haemolytic transfusion reactions.

Blood transfusion demands in a tertiary otolaryngology, head and neck centre: A 5-year retrospective cohort study

OBJECTIVES

To retrospectively analyse and report the utilisation of red blood cell (RBC) transfusion in a tertiary otolaryngology, head and neck centre in the United Kingdom.

BACKGROUND

Twenty-seven per cent of RBC transfusions were for surgical indications in a 2014 England and North Wales survey. Currently, there is limited literature on RBC transfusions in Otolaryngology.

METHODS/MATERIALS

All inpatients admitted primarily under the care of the Otolaryngology, Head and Neck service between January 2015 and December 2019 were analysed. The primary outcomes of interest were number of units of RBC transfused over 5 years and distribution across clinical indications. Secondary outcome measure was cost of RBC transfusions over the same time period.

RESULTS

Most patients receiving transfusions are aged in their sixth and seventh decades. Epistaxis patients utilised 105 RBC units over the 5 years (56% of total RBC units) with emergency epistaxis accounting for 78% of use. Post-operative Head & Neck Cancer surgery with and without reconstruction required 47 RBC units over 5 years (25% of total RBC units). The mean cost incurred by the department over the 5-year period was £6171.49 (SD 1460.25). The cost has fallen by over £2000 over the 5-year period.

CONCLUSION

Blood transfusion use has fluctuated over the last 5 years. Epistaxis and post-operative Head and Neck cancer cases account for significant use compared with other patient groups. Prehabilitation strategies will add value towards mitigating future consumption of RBC.

Unplanned blood use within 24 hours of emergency department presentation: A cohort study in an ageing population

OBJECTIVE

This research aims to elucidate drivers of blood use in an older population, with a focus on unplanned transfusions following ED presentation.

METHODS

In a retrospective cohort study we examined 2015 data for ED presentations and blood use in two hospitals serving a population containing a high proportion (21%) of adults aged ≥65 years. Unplanned blood use was defined as any transfusion ≤24 h of presentation. Data were analysed by age, sex, Major Diagnostic Category, triage category and time to transfusion.

RESULTS

A total of 5294 blood components were transfused, comprising red cells (n = 3784), fresh frozen plasma (n = 657), platelets (n = 563) and cryoprecipitate (n = 290). Men aged ≥65 years were the highest users (40%, 2107 components). Unplanned transfusions accounted for 28% (n = 1057) of annual red cell use. Of 85 014 ED presentations, 494 (0.6%) were associated with unplanned red cell transfusion. Four Major Diagnostic Categories accounted for 81% (n = 853) of unplanned red cell use: gastrointestinal (n = 375), haematology (n = 267), trauma (n = 144) and cardiovascular (n = 67). Over one-fifth of unplanned transfusions (21%, n = 222 of 1057) were associated with ICD-10 codes for anaemia as a reason for presentation within the Haematology Major Diagnostic Category. Adults aged ≥65 years accounted for 62% of overall red cell use and 61% of transfusions ≤24 h of presentation. Odds of unplanned red cell transfusion increased with age, peaking at odds ratio 28.5 (95% confidence interval 14.2-57.4) in those aged 85 years and above.

CONCLUSIONS

Unplanned blood use accounted for 28% of annual hospital blood consumption. Blood component use increased with age and was greatest in older men. A significant burden of anaemia treatment was identified by the ED.

Improvement of transfusion practice and reduction in red blood cell utilization in Belgian hospitals: Results of a national survey and benchmarking

BACKGROUND AND OBJECTIVES

Belgian health authorities launched a national platform in 2011 to improve the quality of transfusion practices and blood use in Belgian hospitals. No data were available about the quality of hospital transfusion practice at the national level.

MATERIALS AND METHODS

Three consecutive national surveys (2012, 2014 and 2016) were performed in all 111 Belgian hospitals to assess the degree of implementation of standards in four process domains related to red blood cell (RBC) transfusion: general quality aspects, ordering of RBC, electronic traceability and reporting of adverse events. The surveys were part of a methodology based on informing, feedback and benchmarking. Responses to questions were analysed semi-quantitatively, and hospitals could score 10 points on each of the domains.

RESULTS

The proportion of hospitals scoring below 5 per domain decreased from 16%, 70%, 14% and 11% (2012) to 2%, 17%, 1% and 1% (2016), respectively. Similarly, scores above 7.5 increased from 25%, 1%, 23% and 36% (2012) to 64%, 30%, 68% and 81% (2016), respectively. In 2016, overall quality of transfusion practices, including the four pre-specified domains, improved continuously with an average total score (max = 40) increasing from 24.2 to 30.5 (p = 0.0005). In addition, there was a decrease in the number of distributed and transfused RBC per 1000 population between 2011 and 2019 from 47.0 to 36.5 and 43.5 to 36.1, respectively.

CONCLUSION

These data show that the applied methodology was a powerful tool to improve quality of transfusion practices and to optimize utilization of RBC at the national level.

Stability of Maleimide-PEG and Mono-Sulfone-PEG Conjugation to a Novel Engineered Cysteine in the Human Hemoglobin Alpha Subunit

In order to use a Hemoglobin Based Oxygen Carrier as an oxygen therapeutic or blood substitute, it is necessary to increase the size of the hemoglobin molecule to prevent rapid renal clearance. A common method uses maleimide PEGylation of sulfhydryls created by the reaction of 2-iminothiolane at surface lysines. However, this creates highly heterogenous mixtures of molecules. We recently engineered a hemoglobin with a single novel, reactive cysteine residue on the surface of the alpha subunit creating a single PEGylation site (βCys93Ala/αAla19Cys). This enabled homogenous PEGylation by maleimide-PEG with >80% efficiency and no discernible effect on protein function. However, maleimide-PEG adducts are subject to deconjugation via retro-Michael reactions and cross-conjugation to endogenous thiol species in vivo. We therefore compared our maleimide-PEG adduct with one created using a mono-sulfone-PEG less susceptible to deconjugation. Mono-sulfone-PEG underwent reaction at αAla19Cys hemoglobin with > 80% efficiency, although some side reactions were observed at higher PEG:hemoglobin ratios; the adduct bound oxygen with similar affinity and cooperativity as wild type hemoglobin. When directly compared to maleimide-PEG, the mono-sulfone-PEG adduct was significantly more stable when incubated at 37°C for seven days in the presence of 1 mM reduced glutathione. Hemoglobin treated with mono-sulfone-PEG retained > 90% of its conjugation, whereas for maleimide-PEG < 70% of the maleimide-PEG conjugate remained intact. Although maleimide-PEGylation is certainly stable enough for acute therapeutic use as an oxygen therapeutic, for pharmaceuticals intended for longer vascular retention (weeks-months), reagents such as mono-sulfone-PEG may be more appropriate.

Not a crystal ball: Mapping opportunities and threats for the future demand of red blood cells in the Netherlands using a scenario approach

BACKGROUND

As Western blood transfusion practices are changing, there is interest and need in anticipating the future demand of blood products and how a blood establishment can actively prepare for various long-term developments. This article provides an overview of how a scenario approach was used to prioritize key categories of drivers for the future demand of red blood cells and the organizational implications thereof for Sanquin, the Dutch national blood establishment.

STUDY DESIGN AND METHODS

Based on previously identified drivers from interviews and a literature review (Step 1), we conducted scenario sessions and a survey to rank a list of drivers ("themes") with its related opportunities and threats (Step 2), to identify mitigating measures per theme through focus groups (Step 3).

RESULTS

In Step 2, 10 themes were found that were classified in terms of importance and uncertainty. These were plotted on a two-dimensional graph with an ellipse to indicate the interquartile ranges per theme. Experts rated the top three most important themes to be the blood supply organization, precision medicine, and red blood cell replacements. In Step 3, focus groups identified specific mitigating measures per theme. These measures had parallel ideas, such as the need for an innovative mentality, internal and external communication and collaboration, and building Sanquin's reputation and trust with the public.

CONCLUSION

Having identified the most important themes with suggestions for mitigating measures, Sanquin can take steps to become adaptive and proactive. Other blood establishments may also use a scenario approach to create contextualized long-term strategies.

Population-Based Analysis of the Impact of Demographics on the Current and Future Blood Supply in the Saarland

Background

The federal state of Saarland (SL) is experiencing the fastest demographic change in the western part of Germany. In this study, we analyzed retrospective data on the current and future supply of red blood cell concentrates (RBC) in this region and compared it to the current and future RBC demand in SL hospitals.

Methods

The projection of the SL blood supply in 2030 was modeled based on SL demographics for age distribution and donation frequency of donors, and the RBC transfusion data for in-house patients. These results were compared to published data on the transfusion demand from the state of Mecklenburg-Western Pomerania (MV).

Results

For the period January 1 to December 31, 2017, a total of 43,205 whole blood donations were collected. The donation frequency in SL never exceeded 80 per 1,000 inhabitants and was well below the numbers in MV. Thirty-one percent of the donors were responsible for 53.5% of the donations, and donors older than 45 years of age contributed highly to the total blood supply. In addition, 40,614 RBC transfusions at 10 SL hospitals were analyzed representing nearly all RBC transfusions for in-house patients in this region. RBC transfusions per 1,000 inhabitants increased with age from 24 (50-54) to 140 (80-84) years. Facing an already existing structural deficit of nearly 8,200 RBC in 2017, the projection predicts a dramatic increase in the regional deficit to >18,300 RBC in 2030.

Conclusion

Our results on RBC demand in SL are comparable but not identical to those projected for the region of MV in eastern Germany. Due to the ongoing demographic changes in Germany as a whole, regular regional monitoring of RBC demand and the age structure of blood recipients and donors should be implemented to allow for better strategic planning in blood transfusion services and hospitals.

Characteristics of Recipients of Red Blood Cell Concentrates in a German Federal State

BACKGROUND

Annual transfusion rates in many European countries range between 25 and 35 red blood cell concentrates (RBCs)/1,000 population. It is unclear why transfusion rates in Germany are considerably higher (approx. 50-55 RBCs/1,000 population).

METHODS

We assessed the characteristics of transfusion recipients at all hospitals of the German federal state Mecklenburg-Western Pomerania during a 10-year longitudinal study.

RESULTS

Although 75% of patients received ≤4 RBCs/patient in 2015 (1 RBC: 11.3%; 2 RBCs: 42.6%; 3 RBCs: 6.3%; 4 RBCs: 15.0%), the mean transfusion index was 4.6 RBCs due to a minority of patients with a high transfusion demand. Two thirds of all RBCs were transfused to only 25% of RBC recipients. Consistently, male patients received a higher number of RBCs (2005: 54.2%; 2015: 56.8%) and had a higher mean transfusion index than female patients (mean 5.1 ± 7.2; median 2; inter-quartile range [IQR] 2-4 vs. mean 4.0 ± 5.8; median 2; IQR 2-4). The absolute transfusion demand decreased between 2005 and 2015 by 13.5% due to a composite of active reduction (clinical practice change) and population decline in the 65- to 75-year age group (lower birth rate cohort 1940-1950); however, with major differences between hospitals (range from -61.0 to +41.4%).

CONCLUSION

Transfusion demand in a population could largely be driven by patients with high transfusion demand. Different treatment practices in this group of patients probably add to the major differences in transfusion demand per 1,000 individuals between countries. The available data cannot prove this hypothesis. Implementation of a diagnosis-related group-based monitoring system is urgently needed to allow informative monitoring on the population level and meaningful comparisons between transfusion practices.

The Impact of Preoperative Intravenous Iron Therapy on Perioperative Outcomes in Cardiac Surgery: A Systematic Review

Background

Anemia is common in cardiac surgery affecting 25-40% of patients and associated with increased blood transfusions, morbidity, mortality, and higher hospital costs. Higher rates of stroke, acute renal injury, and total number of adverse postoperative outcomes have also been reported to be associated with preoperative anemia. This systematic review assessed the current evidence for preoperative intravenous iron on major outcomes following cardiac surgery.

Methods

Outcome measures included postoperative hemoglobin, transfusion rates, major adverse events, and mortality. The review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and articles were identified using PubMed, Cochrane, CLINAHL, WOS, and EMBASE databases. Articles were included if they compared patients with and without preoperative anemia based on treatment with intravenous iron. Quality was assessed using Cochrane Risk of Bias Tool and Newcastle-Ottawa scale, and strength of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach.

Results

Of the articles reviewed, six met inclusion criteria. These included four randomized double-blind prospective cohort studies, one randomized non-blinded prospective study, and one non-randomized non-blinded prospective study with historical control. Across studies, 1,038 patients were enrolled. Two studies showed higher hemoglobin with iron therapy, and only one study showed significant differences in multiple outcomes such as transfusion and morbidity.

Conclusions

Given the paucity of studies and biases within them, the current evidence for treatment with intravenous iron prior to cardiac surgery is weak. More evidence is needed to support the administration of preoperative intravenous iron in cardiac surgery patients.

Patterns of blood use in Sweden from 2008 to 2017: A nationwide cohort study

BACKGROUND

Transfusion patterns in Sweden have not been characterized on a nationwide level.

STUDY DESIGN AND METHODS

We conducted a nationwide descriptive cohort study in Sweden from 2008 to 2017. Data on blood donors, donations, component manufacture, transfusions, and transfused patients were extracted from Swedish portion of the Scandinavian Donations and Transfusions (SCANDAT3-S) database.

RESULTS

A total of 708 436 patients received 5 587 684 red cell, plasma, or platelet transfusions during the study period. The age-standardized transfusion rate decreased markedly during the study period for red cell units (from 53 to 39 units/1000 persons) and plasma units (from 11 to 4.9 units/1000 persons), but remained relatively constant for platelet concentrates. The transfusion rate was 30%-40% higher in males than in females in the first year of life, and higher in males over 45 years than in females. Between age 20 and 45, the majority of red cells were transfused to female patients with obstetric indications, whereas trauma was the predominant indication for male contemporaries. In females over 80 years, the largest proportion of red cells were administered due to trauma. Overall, hematological patients received 36% of all platelet units. There were large regional differences in transfusion rates for red cell units, ranging from less than 30 to greater than 60/1000 persons.

CONCLUSION

Transfusion rates in Sweden remain high but have decreased strikingly during the study period - with the exception of platelet transfusions. Based on the available data, it is difficult to draw firm conclusions about whether transfusion rates can be further reduced.

Improved long-term time-series predictions of total blood use data from England

BACKGROUND

Red blood cells are essential for modern medicine but managing their collection and supply to cope with fluctuating demands represents a major challenge. As deterministic models based on predicted population changes have been problematic, there remains a need for more precise and reliable prediction of use. Here, we develop three new time-series methods to predict red cell use 4 to 52 weeks ahead.

STUDY DESIGN AND METHODS

From daily aggregates of red blood cell (RBC) units issued from 2005 to 2011 from the NHS Blood and Transplant, we generated a new set of non-overlapping weekly data by summing the daily data over 7 days and derived the average blood use per week over 4-week and 52-week periods. We used three new methods for linear prediction of blood use by computing the coefficients using Minimum Mean Squared Error (MMSE) algorithm.

RESULTS

We optimized the time-window size, order of the prediction, and order of the polynomial fit for our data set. By exploiting the annual periodicity of the data, we achieved significant improvements in long-term predictions, as well as modest improvements in short-term predictions. The new methods predicted mean RBC use with a standard deviation of the percentage error of 2.5% for 4 weeks ahead and 3.4% for 52 weeks ahead.

CONCLUSION

This paradigm allows short- and long-term prediction of RBC use and could provide reliable and precise prediction up to 52 weeks ahead to improve the efficiency of blood services and sufficiency of blood supply with reduced costs.

Liberal Versus Restrictive Red Blood Cell Transfusion Thresholds in Hematopoietic Cell Transplantation: A Randomized, Open Label, Phase III, Noninferiority Trial

PURPOSE

Evidence regarding red blood cell (RBC) transfusion practices and their impact on hematopoietic cell transplantation (HCT) outcomes are poorly understood.

PATIENTS AND METHODS

We performed a noninferiority randomized controlled trial in four different centers that evaluated patients with hematologic malignancies requiring HCT who were randomly assigned to either a restrictive (hemoglobin [Hb] threshold < 70 g/L) or liberal (Hb threshold < 90 g/L) RBC transfusion strategy between day 0 and day 100. The noninferiority margin corresponds to a 12% absolute difference between groups in Functional Assessment of Cancer Therapy-Bone Marrow Transplant (FACT-BMT) score relative to baseline. The primary outcome was health-related quality of life (HRQOL) measured by FACT-BMT score at day 100. Additional end points were collected: HRQOL by FACT-BMT score at baseline and at days 7, 14, 28, 60, and 100; transplantation-related mortality; length of hospital stay; intensive care unit admissions; acute graft-versus-host disease; Bearman toxicity score; sinusoidal obstruction syndrome; serious infections; WHO Bleeding Scale; transfusion requirements; and reactions to therapy.

RESULTS

A total of 300 patients were randomly assigned to either restrictive-strategy or liberal-strategy treatment groups between 2011 and 2016 at four Canadian adult HCT centers. After HCT, mean pre-transfusion Hb levels were 70.9 g/L in the restrictive-strategy group and 84.6 g/L in the liberal-strategy group (P < .0001). The number of RBC units transfused was lower in the restrictive-strategy group than in the liberal-strategy group (mean, 2.73 units [standard deviation, 4.81 units] v 5.02 units [standard deviation, 6.13 units]; P = .0004). After adjusting for transfusion type and baseline FACT-BMT score, the restrictive-strategy group had a higher FACT-BMT score at day 100 (difference of 1.6 points; 95% CI, -2.5 to 5.6 points), which was noninferior compared with that of the liberal-strategy group. There were no significant differences in clinical outcomes between the transfusion strategies.

CONCLUSION

In patients undergoing HCT, the use of a restrictive RBC transfusion strategy threshold of 70 g/L was as effective as a threshold of 90 g/L and resulted in similar HRQOL and HCT outcomes with fewer transfusions.

Prediction paradigm involving time series applied to total blood issues data from England

BACKGROUND

Blood products are essential for modern medicine, but managing their collection and supply in the face of fluctuating demands represents a major challenge. As deterministic models based on predicted changes in population have been problematic, there remains a need for more precise and reliable prediction of demands. Here, we propose a paradigm incorporating four different time‐series methods to predict red blood cell (RBC) issues 4 to 24 weeks ahead.

STUDY DESIGN AND METHODS

We used daily aggregates of RBC units issued from 2005 to 2011 from the National Health Service Blood and Transplant. We generated a new set of nonoverlapping weekly data by summing the daily data over 7 days and derived the average blood issues per week over 4‐week periods. We used four methods for linear prediction of blood demand by computing the coefficients with the minimum mean squared error and weighted least squares error algorithms.

RESULTS

We optimized the time‐window size, order of the prediction, and order of the polynomial fit for our data set. The four time‐series methods, essentially using different weightings to data points, gave very similar results and predicted mean RBC issues with a standard deviation of the percentage error of 3.0% for 4 weeks ahead and 4.0% for 24 weeks ahead.

CONCLUSION

This paradigm allows prediction of demand for RBCs and could be developed to provide reliable and precise prediction up to 24 weeks ahead to improve the efficiency of blood services and sufficiency of blood supply with reduced costs.

Audit of red blood cell transfusion in patients with acute leukemia at a tertiary care university hospital

BACKGROUND

Red blood cell (RBC) transfusion support is essential in patients with acute leukemia (AL). A restrictive RBC transfusion approach is assumed to be safe for most individuals with AL. The aim of this audit was to assess RBC transfusion appropriateness in AL patients at an academic center.

STUDY DESIGN AND METHODS

RBC transfusions in acute lymphoblastic leukemia and acute myeloid leukemia patients of all ages between January 1, 2013, and March 31, 2019, were analyzed for adherence to evidence-based criteria. Transfusion appropriateness was compared among ordering specialties, patient locations, and hematologic diagnoses. Pretransfusion hemoglobin was compared between categories. Overtransfusion rates were also analyzed. Descriptive statistics and categorical and numerical tests were employed to determine statistical significance.

RESULTS

A total of 510 RBC transfusions were received by 133 AL patients in the departments of internal medicine, hematology, and pediatrics. Overall, 84.5% were appropriate according to established criteria. Internal medicine was the ordering department with the highest rate of appropriateness (88.1%). The outpatient clinic was the location with the highest adherence (85.9%), whereas the intensive care unit had the lowest (70%; p = 0.03). The reasons for most appropriate and inappropriate transfusions were asymptomatic anemia with a hemoglobin below (60.6%) or above (69.6%) 7 g/dL in patients without cardiac disease, respectively. Overtransfusion was present in 22% of episodes.

CONCLUSION

RBC transfusion in AL patients reflected good adherence to guidelines. However, continuing education in transfusion medicine and prospective chart auditing are needed to improve adherence to established guidelines.

Red blood cell utilization and transfusion triggers in patients diagnosed with chronic lymphocytic leukaemia in Iceland 2003-2016

BACKGROUND AND OBJECTIVES

Revised Icelandic guidelines proposed a restrictive haemoglobin (Hb) threshold of 70 g/l for red blood cell (RBC) transfusions in general, but 100 g/l for malignancies/bone marrow suppression. Chronic lymphocytic leukaemia (CLL) is frequently complicated by anaemia. The objective was to investigate RBC transfusion practices in CLL.

MATERIALS AND METHODS

This retrospective nation-wide study utilized an Icelandic registry of CLL patients diagnosed between 2003 and 2016. Medical records were reviewed and haemoglobin transfusion triggers compared for two periods: Earlier (2003-2012) and latter (2013-2017).

RESULTS

Two hundred and thirteen patients were diagnosed with CLL over the period whereof 77 (36·2%) received RBC transfusion(s). Median time from diagnosis to first transfusion was 2·2 years. Higher age, Rai stage 3/4 at diagnosis (P < 0·05) and chemotherapy (P < 0·001) were associated with increased odds of transfusions. Shorter time to first transfusion correlated with higher age (P < 0·001) and Rai stage (P = 0·02) at diagnosis. The mean Hb trigger was 90·4 and 81·2 in the earlier and latter period respectively (P = 0·01). This difference in Hb triggers was most pronounced in patients without documented bone marrow involvement, or 80·5 g/l compared to 93·5 g/l (P = 0·004). The median time from diagnosis to transfusion was longer in the latter period (2·9 years vs. 1·6 years, P = 0·01). After RBC transfusions the survival decreased significantly (P < 0·001).

CONCLUSION

One-third of CLL patients received RBC transfusions but few were heavily transfused. Older age, Rai stage, and chemotherapy predicted RBC use. The Hb transfusion trigger decreased over time while time to first RBC transfusion increased. RBC transfusions predict poor survival.

A randomised controlled trial and economic evaluation of intraoperative cell salvage during caesarean section in women at risk of haemorrhage: the SALVO (cell SALVage in Obstetrics) trial

BACKGROUND

Caesarean section is associated with blood loss and maternal morbidity. Excessive blood loss requires transfusion of donor (allogeneic) blood, which is a finite resource. Cell salvage returns blood lost during surgery to the mother. It may avoid the need for donor blood transfusion, but reliable evidence of its effects is lacking.

OBJECTIVES

To determine if routine use of cell salvage during caesarean section in mothers at risk of haemorrhage reduces the rates of blood transfusion and postpartum maternal morbidity, and is cost-effective, in comparison with standard practice without routine salvage use.

DESIGN

Individually randomised controlled, multicentre trial with cost-effectiveness analysis. Treatment was not blinded.

SETTING

A total of 26 UK obstetric units.

PARTICIPANTS

Out of 3054 women recruited between June 2013 and April 2016, we randomly assigned 3028 women at risk of haemorrhage to cell salvage or routine care. Randomisation was stratified using random permuted blocks of variable sizes. Of these, 1672 had emergency and 1356 had elective caesareans. We excluded women for whom cell salvage or donor blood transfusion was contraindicated.

INTERVENTIONS

Cell salvage (intervention) versus routine care without salvage (control). In the intervention group, salvage was set up in 95.6% of the women and, of these, 50.8% had salvaged blood returned. In the control group, 3.9% had salvage deployed.

MAIN OUTCOME MEASURES

Primary - donor blood transfusion. Secondary - units of donor blood transfused, time to mobilisation, length of hospitalisation, mean fall in haemoglobin, fetomaternal haemorrhage (FMH) measured by Kleihauer-Betke test, and maternal fatigue. Analyses were adjusted for stratification factors and other factors that were believed to be prognostic a priori. Cost-effectiveness outcomes - costs of resources and service provision taking the UK NHS perspective.

RESULTS

We analysed 1498 and 1492 participants in the intervention and control groups, respectively. Overall, the transfusion rate was 2.5% in the intervention group and 3.5% in the control group [adjusted odds ratio (OR) 0.65, 95% confidence interval (CI) 0.42 to 1.01; p = 0.056]. In a planned subgroup analysis, the transfusion rate was 3.0% in the intervention group and 4.6% in the control group among emergency caesareans (adjusted OR 0.58, 95% CI 0.34 to 0.99), whereas it was 1.8% in the intervention group and 2.2% in the control group among elective caesareans (adjusted OR 0.83, 95% CI 0.38 to 1.83) (interaction p = 0.46, suggesting that the difference in effect between subgroups was not statistically significant). Secondary outcomes did not differ between groups, except for FMH, which was higher under salvage in rhesus D (RhD)-negative women with RhD-positive babies (25.6% vs. 10.5%, adjusted OR 5.63, 95% CI 1.43 to 22.14; p = 0.013). No case of amniotic fluid embolism was observed. The additional cost of routine cell salvage during caesarean was estimated, on average, at £8110 per donor blood transfusion avoided.

CONCLUSIONS

The modest evidence for an effect of routine use of cell salvage during caesarean section on rates of donor blood transfusion was associated with increased FMH, which emphasises the need for adherence to guidance on anti-D prophylaxis. We are unable to comment on long-term antibody sensitisation effects. Based on the findings of this trial, cell salvage is unlikely to be considered cost-effective.

FUTURE WORK

Research into risk of alloimmunisation among women exposed to cell salvage is needed.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN66118656.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 2. See the NIHR Journals Library website for further project information.

Impacts of Aging on Anemia Tolerance, Transfusion Thresholds, and Patient Blood Management

Evidence-based patient blood management guidelines commonly recommend restrictive hemoglobin thresholds of 70 to 80 g/L for asymptomatic adults. However, most transfusion trials have enrolled adults across a broad age span, with few exclusive to older adults. Our recent meta-analysis of transfusion trials that focused on older adults paradoxically found lower mortality and fewer cardiac complications when these patients were managed using higher hemoglobin thresholds. We postulate that declining cardiac output with age contributes to deteriorating oxygen delivery capacity which impacts anemia-associated outcomes in older adults and propose a model to explain this age-related difference. We reviewed evidence concerning the pathophysiology of aging to explore the disparity in transfusion trial outcomes related to hemoglobin thresholds in different age groups. The literature was searched for normative cardiac output values at different ages in healthy adults. Using normative peak cardiac output data, we modeled oxygen delivery capacity in young, middle-aged, and older adults at a range of hemoglobin levels. Cardiovascular and pulmonary systems are impacted by age-related pathophysiological changes. Diminishing peak cardiac output associated with aging reduces the maximal oxygen delivery achievable under metabolic stress. Hence, at low hemoglobin levels, older adults are more susceptible to tissue hypoxia than younger adults. Our model predicts that an older adult with a hemoglobin of 100 g/L has a similar peak oxygen delivery capacity to a young adult with a hemoglobin of 70 g/L. Age-related pathophysiological changes provide some explanation as to why older adults have a lower tolerance for anemia than younger adults. This indicates the need for patient blood management hemoglobin thresholds specific to older as distinct from younger adults. The primary application of this model is in the consideration of patients rehabilitating to life outside hospital. It is important to note that pathophysiological changes associated with critical illness and major surgery are more complex than can be described in a simple model based on cardiac output and hemoglobin concentration. However, our review of oxygen transport and delivery in health and disease states allows the model to be considered in the context of treatment decisions for anemic adults in a range of hospital and community settings.

Outcomes following restrictive or liberal red blood cell transfusion in patients with lower gastrointestinal bleeding

BACKGROUND

Restrictive red blood cell (RBC) transfusion reduces mortality and rebleeding after upper gastrointestinal bleeding (UGIB). However, there is no evidence to guide transfusion strategies in lower gastrointestinal bleeding (LGIB).

AIM

To assess the association between RBC transfusion strategies and outcomes in patients with LGIB METHODS: This was a post hoc analysis of the UK National Comparative Audit of LGIB and the Use of Blood. The relationships between liberal RBC transfusion and clinical outcomes of rebleeding, mortality and a composite outcome for safe discharge were examined. Transfusion strategy was dichotomised and defined as "liberal" when transfusion was administered for haemoglobin (Hb) ≥80 g/L (or ≥90 g/L in patients with acute coronary syndrome) or major haemorrhage, and "restrictive" otherwise. Multivariable logistic regression models were used to assess the independent association between liberal RBC transfusion and outcomes.

RESULTS

Of 2528 consecutive patients enrolled from 143 hospitals in the original study, 666 (26.3%) received RBC transfusion (mean age 73.3 ± 16 years, 49% female, initial mean haemoglobin 90 ± 24 g/L, 2.3% had haemodynamic instability). The rebleeding rate in transfused patients was 42.3%. After adjusting for potential confounders, there was no difference between liberal and restrictive RBC transfusion strategies for the odds of rebleeding (OR 0.89, 95% CI 0.6-1.22), in-hospital mortality (OR 0.54, 95% CI 0.3-1.1) or of achieving the composite outcome (OR 0.72, 95% CI 0.5-1.1).

CONCLUSION

Although these results could be due to residual confounding, they provide an important foundation for the design of randomised trials to evaluate transfusion strategies for LGIB.

Patient Presentation, Risk Stratification, and Initial Management in Acute Lower Gastrointestinal Bleeding

The approach to lower gastrointestinal bleeding (LGIB) has evolved over the last few years to incorporate a multidisciplinary management strategy. Although the causes of LGIB vary depending on the age and comorbid conditions of patients, the initial resuscitation and principles of optimizing patients' condition before endoscopic evaluation, when appropriate, are the cornerstones to clinical care. The role of risk stratification is to triage patients as well as to mobilize health care resources based on predicted outcomes. Individualized management according to patients' comorbid conditions has been a focus in most recent guidelines.

Acute lower GI bleeding in the UK: patient characteristics, interventions and outcomes in the first nationwide audit

OBJECTIVE

Lower GI bleeding (LGIB) is a common reason for emergency hospital admission, although there is paucity of data on presentations, interventions and outcomes. In this nationwide UK audit, we describe patient characteristics, interventions including endoscopy, radiology and surgery as well as clinical outcomes.

DESIGN

Multicentre audit of adults presenting with LGIB to UK hospitals over 2 months in 2015. Consecutive cases were prospectively enrolled by clinical teams and followed for 28 days.

RESULTS

Data on 2528 cases of LGIB were provided by 143 hospitals. Most were elderly (median age 74 years) with major comorbidities, 29.4% taking antiplatelets and 15.9% anticoagulants. Shock was uncommon (58/2528, 2.3%), but 666 (26.3%) received a red cell transfusion. Flexible sigmoidoscopy was the most common investigation (21.5%) but only 2.1% received endoscopic haemostasis. Use of embolisation or surgery was rare, used in 19 (0.8%) and 6 (0.2%) cases, respectively. 48% patients underwent no inpatient investigations. The most common diagnoses were diverticular bleeding (26.4%) and benign anorectal conditions (16.7%). Median length of stay was 3 days, 13.6% patients rebled during admission and 4.4% were readmitted with bleeding within 28 days. In-hospital mortality was 85/2528 (3.4%) and was highest in established inpatients (17.8%, p<0.0001) and in patients experiencing rebleeding (7.1%, p<0.0001).

CONCLUSIONS

Patients with LGIB have a high burden of comorbidity and frequent antiplatelet or anticoagulant use. Red cell transfusion was common but most patients were not shocked and required no endoscopic, radiological or surgical treatment. Nearly half were not investigated. In-hospital mortality was related to comorbidity, not severe haemorrhage.

Red blood cell transfusion support and management of secondary iron overload in patients with haematological malignancies in the Netherlands: a survey

BACKGROUND AND OBJECTIVES

Evidence-based guidelines on optimal triggers for red blood cell (RBC) transfusion in patients with haematological malignancies exist, but the evidence is weak. Secondary iron overload is an often overlooked chronic complication of RBC transfusions, and also here, guidelines are either lacking or lack international consensus. Our aim was to evaluate the triggers for RBC transfusion support and management of secondary iron overload among haematologists in the Netherlands.

MATERIALS AND METHODS

For this cross-sectional study, all haematologists and haematologists in training in the Netherlands were sent a web-based, 25-question survey including three clinical scenarios. The survey distribution took place between 19 November 2015 and 26 January 2016.

RESULTS

Seventy-seven responses were received (24%), well distributed among community and university hospitals. A wide variation in haemoglobin triggers existed: 5·6-9·5 g/dl (median: 8·0 g/dl). Personalization of this trigger was mostly based on (estimated) cardiopulmonary compensation capacity of patients. About 65% of respondents reported two RBC units per transfusion episode (range 1-3). For monitoring secondary iron overload, serum ferritin was most frequently measured (97%), while a value of 1000-1500 μg/l was the most common cut-off to initiate treatment (39%). For 81% of respondents, phlebotomies were the first choice of treatment, although often the haemoglobin level was considered a limiting factor.

CONCLUSION

Our results confirm large reported variation in daily practice among haematologists in the Netherlands regarding RBC transfusion support and management of secondary iron overload. Future studies providing better evidence are needed to improve guidelines specific for patients with haematological malignancies.