Intraoperative transfusion practices in Europe

Development and validation of machine learning models for intraoperative blood transfusion prediction in severe lumbar disc herniation

Lumbar disc herniation (LDH) is a common cause of lower back pain and sciatica, and posterior lumbar interbody fusion (PLIF) is always employed. This multicenter retrospective study investigates predicting intraoperative blood transfusion for LDH patients undergoing PLIF in China. The research includes 6,241 patients from 22 medical centers and employs 8 feature selection methods and 10 machine learning models, including an integrated stacking model. The optimal predictive model was selected based on the receiver operating characteristic area under the curve, clinical applicability, and computational efficiency. Among the evaluated combinations, the simulated annealing support vector machine recursive + stacking model achieved the highest performance with an area under the curve of 0.884, supported by robust calibration and decision curve analyses. A publicly accessible web calculator was developed to assist clinicians in decision-making. This work significantly enhances intraoperative transfusion predictions, providing valuable tools for improving patient management.

Hospital variation in quality indicators for patient blood management in total knee and hip arthroplasty: a retrospective cohort study

BACKGROUND

Anaemia, blood loss, and blood transfusion are critical aspects of patient care in major orthopaedic surgery. We assessed hospital adherence to guideline-recommended Patient Blood Management (PBM) care, analysed variations between hospitals, and validated two composite indicators of hospital PBM performance in patients undergoing total knee arthroplasty (TKA) or total hip arthroplasty (THA).

METHODS

This retrospective cohort study included all primary TKA and THA procedures performed during 2021 across 39 hospitals in Spain. We assessed hospital adherence to key guideline-recommended PBM interventions using nine individual quality indicators and two types of composite quality indicators (cQIs): opportunity-based (cQI1) and all-or-none (cQI2). We validated these cQIs by analysing their associations with the adjusted total transfusion index using linear regression.

RESULTS

We included 8561 patient episodes from 33 hospitals in the analysis. Delivery of PBM care was similar for TKA and THA. Patients received 62% of the analysed PBM interventions and only 12% of patients underwent the full PBM pathway. Higher hospital cQIs scores were associated with a lower adjusted total transfusion index, both in TKA and THA. The greatest association was found for cQI1 in THA patients (β=-1.18 [95% confidence interval -2.00 to -0.36]; P=0.007).

CONCLUSIONS

Hospital adherence to guideline-recommended patient blood management care in total hip and knee arthroplasty was suboptimal and varied across centres. Using data that are widely available in hospitals, quality indicators and composite scores could become valuable tools for patient blood management monitoring and comparisons between healthcare organisations.

Perioperative Transfusion Practices in Adults Having Noncardiac Surgery

Surgical patients are often transfused to manage bleeding and anemia. Best practices for red blood cell (RBC) transfusion administration in patient having noncardiac surgery remains controversial and a robust evaluation and description of perioperative transfusion practices is lacking. We characterized perioperative hemoglobin concentrations and transfusion practices from the prospective VISION cohort which included 39,222 patients aged ≥45 years who had inpatient noncardiac surgery. Variations in transfusion practices were analyzed using hierarchical mixed models, and associations with mortality and complications were evaluated using a nested frailty survival model. Within the cohort, 16.1% (n = 6296) were given perioperative RBC transfusions, with the fraction declining from 20% to 13% over the 6-year study period. The proportion of patients transfused varied by surgery type from 6.4% for low-risk operations (i.e., minor surgery) to 31.5% for orthopedic surgeries. Variations were largely associated with patient hemoglobin concentrations, but also with center (range: 3.7%-27.3%) and country (0.4%-25.3%). Even after adjusting for baseline hemoglobin, comorbidities and type of surgery, both center and country were significant sources of variation in transfusion practices. Among transfused participants, 60.4% (n = 3728/6170) had at least 1 hemoglobin concentration ≤80g/L and 86.0% (n = 5305/6170) had at least 1 hemoglobin concentration ≤90g/L, suggesting that relatively restrictive transfusion strategies were used in most. The proportion of patients receiving at least 1 RBC transfusion declined from 20% to 13% over 6 years. However, there was considerable unexplained variation in transfusion practices.

Intraoperative and immediate postoperative transfusion: Clinical-hematological profile of transfunded patients in a university hospital

INTRODUCTION

The transfusion practice by surgery blood reserve, varied among services, must be performed through the rational and restrictive use of blood components because it is a scarce and expensive resource for health care services.

OBJECTIVE

Analyze the use of blood products for surgery blood reserve by means of the study of the clinical-hematological profile of patients submitted to intraoperative and immediate postoperative transfusions.

METHODS

This was an observational, cross-sectional, and retrospective study, conducted by collecting biological, operational, and laboratory variables, involving 680 patients at a university hospital who had elective surgery with surgery blood reserve request sent during the period from October 2021 to October 2022.

RESULTS

The overall transfusion rate was 25.44%, and the mean preoperative hemoglobin level of transfused patients was 9.74 ± 2.50 g/dL, with the mean number of transfusions packed red blood cell units was 1.58 ± 0.77. Patients with higher preoperative hemoglobin levels were less likely to have transfusion (p < 0.001) and patients who had surgical oncologic were more likely to require transfusion (p = 0.048). The transfusion rate of packed red blood cells and platelets concentrates, compared to what was requested, was 15.86% and 5.82%.

CONCLUSION

There is a tendency of transfusions to follow restrictive models, with higher transfusion probability in surgical oncologic. Furthermore, there should be more a conscise use of the surgery blood reserves request.

Post-operative anemia in children undergoing elective neurosurgery: An analysis of incidence, risk factors, and outcomes

Objectives

Pediatric neurosurgeries carry a considerable risk of intraoperative bleeding and, subsequently, anemia in the post-operative period. Postoperative anemia is often multifactorial with several factors contributing to its occurrence. The present study aims to quantify the incidence of postoperative anemia, identify potential risk factors, and assess the impact of post-operative anemia on clinical outcomes in the pediatric neurosurgery population.

Materials and Methods

This was a single-center and retrospective cohort study which included children <18 years of age undergoing elective neurosurgery. The data were extracted from the electronic and physical patient health records. Post-operative anemia was defined for this study as a hemoglobin value below 10 g/dL at any time up to 3 days after surgery.

Results

A total of 300 children were recruited during the study period. The incidence of post-operative anemia after elective pediatric neurosurgery was 21.33%. Children in the post-operative anemia group were younger (P = 0.004), had lower pre-operative hemoglobin values (P < 0.001), belonged to higher American Society of Anesthesiologists (ASA) physical status (P = 0.023), underwent predominantly supratentorial (P = 0.041) and non-tumor surgeries (0.004), and received lesser intraoperative blood transfusion (P = 0.010) compared to no post-operative anemia group. The factors that remained predictive of post-operative anemia on multivariate analysis were ASA physical status (P = 0.018, odds ratio [OR] = 1.94, 95% confidence interval [CI] of 1.12-3.36), pre-operative hemoglobin (P < 0.001, OR = 0.64, 95% CI of 0.50-0.82), and intraoperative transfusion (P = 0.028, OR = 0.45, 95% CI of 0.22-0.92).

Conclusion

Optimization of modifiable risk factors is essential to reduce the occurrence of post-operative anemia and improve outcomes in pediatric neurosurgical patients.

Patient Blood Management in Microsurgical Procedures for Reconstructive Surgery

Introduction: The main purpose of reconstructive surgery (RS) is to restore the integrity of soft tissues damaged by trauma, surgery, congenital deformity, burns, or infection. Microsurgical techniques consist of harvesting tissues that are separated from the vascular sources of the donor site and anastomosed to the vessels of the recipient site. In these procedures, there are some preoperative modifiable factors that have the potential to influence the outcome of the flap transfer and its anastomosis. The management of anemia, which is always present in the postoperative period and plays a decisive role in the implantation of the flap, covers significant importance, and is associated with clinical and laboratory settings of chronic inflammation. Methods: Chronic inflammatory anemia (ACD) is a constant condition in patients who have undergone RS and correlates with the perfusion of the free flap. The aim of this treatment protocol is to reduce the transfusion rate by maintaining both a good organ perfusion and correction of the patient's anemic state. From January 2017 to September 2019, we studied 16 patients (16 males, mean age 38 years) who underwent microsurgical procedures for RS. Their hemoglobin (Hb) levels, corpuscular indexes, transferrin saturation (TSAT) ferritin concentrations and creatinine clearance were measured the first day after surgery (T0), after the first week (T1), and after five weeks (T2). At T0, all the patients showed low hemoglobin levels (average 7.4 g/dL, STD 0.71 range 6.2-7.4 g dL-1), with an MCV of 72, MCH of 28, MCHC of 33, RDW of 16, serum iron of 35, ferritin of 28, Ret% of 1.36, TRF of 277, creatinine clearance of 119 and high ferritin levels (range 320-560 ng mL-1) with TSAT less than 20%. All the patients were assessed for their clinical status, medical history and comorbidities before the beginning of the therapy. Results: A collaboration between the two departments (Department of Transfusion Medicine and Department of Reconstructive Surgery) resulted in the application of a therapeutic protocol with erythropoietic stimulating agents (ESAs) (Binocrit 6000 UI/week) and intravenous iron every other day, starting the second day after surgery. Thirteen patients received ESAs and FCM (ferric carboxymaltose, 500-1000 mg per session), three patients received ESAs and iron gluconate (one vial every other day). No patients received blood transfusions. No side effects were observed, and most importantly, no limb or flap rejection occurred. Conclusions: Preliminary data from our protocol show an optimal therapeutic response, notwithstanding the very limited scientific literature and data available in this specific surgical field. The enrollment of further patients will allow us to validate this therapeutic protocol with statistically sound data.

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.

Restrictive blood transfusion and 1-year mortality in patients undergoing open abdominal surgery: A retrospective propensity score-matched cohort study

BACKGROUND

The importance of patient blood management is increasingly recognized in surgery patients. This study aimed to examine the effect of perioperative restrictive blood transfusion on 1-year mortality and blood transfusion rate in open abdominal surgery.

METHODS

We retrospectively studied 452 consecutive patients who underwent open abdominal surgery before (liberal group: 233 patients) and after (restrictive group: 219 patients) implementing intraoperative restrictive transfusion of red blood cell. The trigger levels of hemoglobin were less than 9-10 g/dL in the liberal group and less than 7-8 g/dL in the restrictive group. All-cause mortality at 1-year as the primary outcome and the transfusion rate of any allogeneic blood products as secondary outcome were compared between the liberal group and the restrictive group by the propensity-score matching.

RESULTS

Among a total of 452 patients (69 ± 11 yr., 70.5 % men), overall mortality at 1 year was 8.4 % and the proportion of patients who received any allogeneic blood products was 19.6 %. Compared with 155 propensity-score matched patients of the liberal group, 155 matched patients of the restrictive group had significantly lower 1-year mortality (4 [2.5 %] versus 18 [11.6 %], p = 0.003, percent absolute risk reduction [%ARR]; 9.0, 95 % confidential interval [CI], 3.1-14.7) and had significantly lower proportion of patients who received any allogeneic blood products (21 [13.5 %] versus 41 [26.4 %], p = 0.006, %ARR; 12.9, 95 % CI, 3.9-21.5).

CONCLUSIONS

The results of this study indicate that intraoperative restrictive blood transfusion reduces 1-year mortality and the transfusion rate of allogeneic blood products.

The Limits of Acute Anemia

For many years, physicians’ approach to the transfusion of allogeneic red blood cells (RBC) was not individualized. It was accepted that a hemoglobin concentration (Hb) of less than 10 g/dL was a general transfusion threshold and the majority of patients were transfused immediately. In recent years, there has been increasing evidence that even significantly lower hemoglobin concentrations can be survived in the short term without sequelae. This somehow contradicts the observation that moderate or mild anemia is associated with relevant long-term morbidity and mortality. To resolve this apparent contradiction, it must be recognized that we have to avoid acute anemia or treat it by alternative methods. The aim of this article is to describe the physiological limits of acute anemia, match these considerations with clinical realities, and then present “patient blood management” (PBM) as the therapeutic concept that can prevent both anemia and unnecessary transfusion of RBC concentrates in a clinical context, especially in Intensive Care Units (ICU). This treatment concept may prove to be the key to high-quality patient care in the ICU setting in the future.

Patient Blood Management: Improving Outcomes for Millions While Saving Billions. What Is Holding It Up?

Patient blood management (PBM) offers significantly improved outcomes for almost all medical and surgical patient populations, pregnant women, and individuals with micronutrient deficiencies, anemia, or bleeding. It holds enormous financial benefits for hospitals and payers, improves performance of health care providers, and supports public authorities to improve population health. Despite this extraordinary combination of benefits, PBM has hardly been noticed in the world of health care. In response, the World Health Organization (WHO) called for its 194 member states, in its recent Policy Brief, to act quickly and decidedly to adopt national PBM policies. To further support the WHO's call to action, this article addresses 3 aspects in more detail. The first is the urgency from a health economic perspective. For many years, growth in health care spending has outpaced overall economic growth, particularly in aging societies. Due to competing economic needs, the continuation of disproportionate growth in health care spending is unsustainable. Therefore, the imperative for health care leaders and policy makers is not only to curb the current spending rate relative to the gross domestic product (GDP) but also to simultaneously improve productivity, quality, safety of patient care, and the health status of populations. Second, while PBM meets these requirements on an exceptional scale, uptake remains slow. Thus, it is vital to identify and understand the impediments to broad implementation. This includes systemic challenges such as the so-called "waste domains" of failure of care delivery caused by malfunctions of health care systems, failure of care coordination, overtreatment, and low-value care. Other impediments more specific to PBM are the misperception of PBM and deeply rooted cultural patterns. Third, understanding how the 3Es-evidence, economics, and ethics-can effectively be used to motivate relevant stakeholders to take on their respective roles and responsibilities and follow the urgent call to implement PBM as a standard of care.

Predicting organ functioning with and without blood transfusion in critically ill patients with anemia

BACKGROUND

To develop a model for the prediction of the (most likely) effect of red blood cell (RBC) transfusion on subsequent organ functioning in nonbleeding critically ill patients with hemoglobin concentrations between 6 and 9 g/dL.

STUDY DESIGN AND METHODS

We conducted a retrospective cohort study using electronic health care data of nonbleeding patients admitted between November 2004 and May 2016 at the intensive care unit (ICU) of the Leiden University Medical Center, The Netherlands. We analyzed the associations between transfusion (yes/no) and next-day SOFA scores (Sequential Organ Failure Assessment-as a measure for organ functioning) for all observed combinations of hemoglobin values (between 6 and 9 g/dL) and concurrent clinical variables.

RESULTS

Data of 6425 ICU admission of 5756 critically ill patients with 28,702 hemoglobin values between 6 and 9 g/dL (transfusion decision moments) of which 22.1% were followed by a transfusion were analyzed. The adjusted average difference between the next-day SOFA score of transfused versus not-transfused patients was 0.08 (95% confidence interval [CI] -0.03 to 0.18). At singular transfusion decision moments, the score predicted a beneficial effect of transfusion on next-day SOFA score for some subgroups and medical conditions and a harmful effect in other occasions.

CONCLUSIONS

Among these critically ill patients with hemoglobin concentrations between 6 and 9 g/dL the population average effect of transfusion on the next SOFA score was negligible. Further, our results support caution in clinical decision-making regarding transfusion of critical ill, nonbleeding ICU patients.

Intraoperative transfusion practices and perioperative outcome in the European elderly: A secondary analysis of the observational ETPOS study

The demographic development suggests a dramatic growth in the number of elderly patients undergoing surgery in Europe. Most red blood cell transfusions (RBCT) are administered to older people, but little is known about perioperative transfusion practices in this population. In this secondary analysis of the prospective observational multicentre European Transfusion Practice and Outcome Study (ETPOS), we specifically evaluated intraoperative transfusion practices and the related outcomes of 3149 patients aged 65 years and older. Enrolled patients underwent elective surgery in 123 European hospitals, received at least one RBCT intraoperatively and were followed up for 30 days maximum. The mean haemoglobin value at the beginning of surgery was 108 (21) g/l, 84 (15) g/l before transfusion and 101 (16) g/l at the end of surgery. A median of 2 [1-2] units of RBCT were administered. Mostly, more than one transfusion trigger was present, with physiological triggers being preeminent. We revealed a descriptive association between each intraoperatively administered RBCT and mortality and discharge respectively, within the first 10 postoperative days but not thereafter. In our unadjusted model the hazard ratio (HR) for mortality was 1.11 (95% CI: 1.08-1.15) and the HR for discharge was 0.78 (95% CI: 0.74-0.83). After adjustment for several variables, such as age, preoperative haemoglobin and blood loss, the HR for mortality was 1.10 (95% CI: 1.05-1.15) and HR for discharge was 0.82 (95% CI: 0.78-0.87). Pre-operative anaemia in European elderly surgical patients is undertreated. Various triggers seem to support the decision for RBCT. A closer monitoring of elderly patients receiving intraoperative RBCT for the first 10 postoperative days might be justifiable. Further research on the causal relationship between RBCT and outcomes and on optimal transfusion strategies in the elderly population is warranted. A thorough analysis of different time periods within the first 30 postoperative days is recommended.

Acute hypervolemic hemodilution combined with controlled hypotension to minimize blood loss during operations of spine fusion: remifentanil versus magnesium sulfate

Background

Blood loss is one of the major problems during operations of spine fusion. Several blood-conservative measures were applied to reduce the incidence of blood loss—among them, acute hypervolemic hemodilution (AHH) and controlled hypotension (CH). This study was designed to detect the effect of combination of AHH with CH induced by remifentanil versus magnesium sulfate on the volume of blood loss, allogeneic blood transfusion, hemodynamics, coagulation, and electrolytes during operations for spine fusion which are risky operations with high incidence of blood loss and blood transfusion. Sixty patients scheduled for posterior fusion of the spine were randomly allocated into three groups of 20 patients each (group I (AHH), group II (AHH combined with remifentanil-based CH), and group III (AHH combined with magnesium sulfate-based CH)). Estimated blood loss and total volume of packed red blood cells (PRBCS) transfused were recorded. Arterial blood pressure (ABP) and heart rate (HR) measures were recorded. Blood samples were obtained for the detection of hemoglobin (Hb) and hematocrit (HCT).

Results

Estimated blood loss, percentage blood loss, and intraoperative RBC transfusion units were significantly high in group I in relation to group II and group III (Table 2). Cardiac output was significantly higher in group I in relation to group II and group III at 10, 15, 30, 45, and 60 min after start of AHH. MBP and HR results were significantly high in group I in comparison with group II and group III at 30, 45, 60, and 90 min and 2 and 3 h after start of study drugs. CVP results were significantly high in group I in relation to group II and group III at 15, 30, 45, 60, and 90 min after start of AHH. PTT was significantly increased in the three study groups in comparison with baseline inside each group after AHH.

Conclusion

Combination of AHH with CH induced by remifentanil or magnesium sulfate was associated with reduction in estimated blood loss, and total volume of PRBCS transfused. There was no significant difference between hemodynamic parameters with the use of remifentanil or magnesium sulfate except that SBP, DBP, and MBP results were significantly high with magnesium sulfate at 15 min after drug infusion. There was significant increase in PT and PTT after AHH that was not reflected by significant blood oozing from the operative field, or by difficulty in hemostasis.

Künstliche Sauerstofftransporter können mehr als Sauerstoff liefern

Zum gegenwärtigen Zeitpunkt ist in der EU und den USA kein artifizieller Sauerstofftransporter zugelassen. Hämoglobin-basierte Sauerstoff-Carrier (HBOC) sind bereits seit Jahrzehnten Gegenstand wissenschaftlicher Untersuchungen. Ein wesentliches Hindernis bei der Zulassung war bisher der Anspruch der Entwickler, einen universell einsetzbaren Blutersatz zu produzieren. Die Beschränkung auf eine Indikation scheint erfolgversprechender zu sein. Der Ansatz, nicht nur Sauerstoff von der Lunge zum Gewebe, sondern auch der Abtransport von Kohlendioxid vom Gewebe zur Lunge zu transportieren, der effektiver als mit Erythrozyten durchgeführt werden kann, erscheint besonders attraktiv. Aufgrund vielversprechender präklinischer sowie klinischer Untersuchungen besteht die Hoffnung, dass in absehbarer Zeit auch in der EU künstliche Sauerstofftransporter für therapeutische Zwecke zur Verfügung stehen werden.

RBC Transfusion Triggers: Is There Anything New?

For many years, in daily clinical practice, the traditional 10/30 rule (hemoglobin 10 g/dL - hematocrit 30%) has been the most commonly used trigger for blood transfusions. Over the years, this approach is believed to have contributed to a countless number of unnecessary transfusions and an unknown number of overtransfusion-related deaths. Recent studies have shown that lower hemoglobin levels can safely be accepted, even in critically ill patients. However, even these new transfusion thresholds are far beyond the theoretical limits of individual anemia tolerance. For this reason, almost all publications addressing the limits of acute anemia recommend physiological transfusion triggers to indicate the transfusion of erythrocyte concentrates as an alternative. Although this concept appears intuitive at first glance, no solid scientific evidence supports the safety and benefit of physiological transfusion triggers to indicate the optimal time point for transfusion of allogeneic blood. It is therefore imperative to continue searching for the most sensitive and specific parameters that can guide the clinician when to transfuse in order to avoid anemia-induced organ dysfunction while avoiding overtransfusion-related adverse effects. This narrative review discusses the concept of anemia tolerance and critically compares hemoglobin-based triggers with physiological transfusion for various clinical indications.

Peri-operative blood transfusion in elective major surgery: incidence, indications and outcome - an observational multicentre study

BACKGROUND

Patients' demographic and epidemiological characteristics, local variations in clinicians' knowledge and experience and types of surgery can influence peri-operative transfusion practices. Sharing data on transfusion practices and recipients may improve patients' care and implementation of Patient Blood Management (PBM).

MATERIALS AND METHODS

This was a multicentre, prospective, observational, cross-sectional study that included 61 centres. Clinical and transfusion data of patients undergoing major elective surgery were collected; transfusion predictors and patients' outcomes were analysed.

RESULTS

Of 6,121 patients, 1,579 (25.8%) received a peri-operative transfusion. A total of 5,812 blood components were transfused: red blood cells (RBC), fresh-frozen plasma and platelets in 1,425 (23.3%), 762 (12.4%) and 88 (1.4%) cases, respectively). Pre-operative anaemia was identified in 2,019 (33%) patients. Half of the RBC units were used by patients in the age group 45-69 years. Specific procedures with the highest RBC use were coronary artery bypass grafting (16.9% of all units) and hip arthroplasty (14.9%). Low haemoglobin concentration was the most common indication for intra-operative RBC transfusion (57%) and plasma and platelet transfusions were mostly initiated for acute bleeding (61.3% and 61.1%, respectively). The RBC transfusion rate in study centres varied from 2% to 72%. RBC transfusion was inappropriate in 99% (n=150/151) of pre-operative, 23% (n=211/926) of intra-operative and 43% (n=308/716) of post-operative RBC transfusion episodes. Pre-operative haemoglobin, increased blood loss, open surgery and duration of surgery were the main independent predictors of intra-operative RBC transfusion. Low pre-operative haemoglobin concentration was independently associated with post-operative pulmonary complications.

CONCLUSIONS

These findings identified areas for improvement in peri-operative transfusion practice and PBM implementation in Turkey.

Machine learning-based prediction of transfusion

Background

The ability to predict transfusions arising during hospital admission might enable economized blood supply management and might furthermore increase patient safety by ensuring a sufficient stock of red blood cells (RBCs) for a specific patient. We therefore investigated the precision of four different machine learning–based prediction algorithms to predict transfusion, massive transfusion, and the number of transfusions in patients admitted to a hospital.

Study Design and Methods

This was a retrospective, observational study in three adult tertiary care hospitals in Western Australia between January 2008 and June 2017. Primary outcome measures for the classification tasks were the area under the curve for the receiver operating characteristics curve, the F₁ score, and the average precision of the four machine learning algorithms used: neural networks (NNs), logistic regression (LR), random forests (RFs), and gradient boosting (GB) trees.

Results

Using our four predictive models, transfusion of at least 1 unit of RBCs could be predicted rather accurately (sensitivity for NN, LR, RF, and GB: 0.898, 0.894, 0.584, and 0.872, respectively; specificity: 0.958, 0.966, 0.964, 0.965). Using the four methods for prediction of massive transfusion was less successful (sensitivity for NN, LR, RF, and GB: 0.780, 0.721, 0.002, and 0.797, respectively; specificity: 0.994, 0.995, 0.993, 0.995). As a consequence, prediction of the total number of packed RBCs transfused was also rather inaccurate.

Conclusion

This study demonstrates that the necessity for intrahospital transfusion can be forecasted reliably, however the amount of RBC units transfused during a hospital stay is more difficult to predict.

Patient Blood Management for primary hip and knee replacement. A survey among POWER.2 study researchers

BACKGROUND

Implementation of Patient Blood Management programs remain variable in Europe, and even in centres with well-established PBM programs variability exists in transfusion practices.

OBJECTIVES AND METHODS

We conducted a survey in order to assess current practice in perioperative Patient Blood Management in patients undergoing total hip and knee replacement among researchers involved in POWER.2 Study in Spain (an observational prospective study evaluating enhanced recovery pathways in orthopaedic surgery).

RESULTS

A total of 322 responses were obtained (37.8%). Half of responders check Haemoglobin levels in patients at least 4 weeks before surgery; 35% treat all anaemic patients, although 99.7% consider detection and treatment of preoperative anaemia could influence the postoperative outcomes. Lack of infrastructure (76%) and lack of time (51%) are the main stated reasons not to treat anaemic patients. Iron status is routinely checked by 19% before surgery, and 36% evaluate it solely in the anaemic patient. Hb<9.9 g/dl is the threshold to delay surgery for 61% of clinicians, and 22% would consider transfusing preoperatively clinically stable patients without active bleeding. The threshold to transfuse patients without cardiovascular disease is 8 g/dl for 43%, and 7 g/dl for 34% of the responders; 75% of clinicians consider they use "restrictive thresholds", and 90% follow the single unit transfusion policy.

CONCLUSIONS

The results of our survey show variability in clinical practice in Patient Blood Management in major orthopaedic surgery, despite being the surgery with the greatest tradition in these programs.

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

OBJECTIVE

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

DESIGN

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Evaluation for Perioperative Blood Transfusion during Major Abdominal Procedures in a Pediatric Population: A Retrospective Observation Cohort Study

Objectives

The purpose of this study was to examine modifiable factors and their impact on perioperative blood transfusion for pediatric patients with major abdominal procedures.

Methods

This is a retrospective review of 1,506 patients who underwent major abdominal surgical procedures in a tertiary medical center from January 2008 to June 2018. Clinical data about blood administration including triggers and targets for intra- or postoperative transfusion were collected and analyzed. The inappropriate transfusion (transfusion > 8.0 g/dL of hemoglobin [Hb] trigger) and overtrans-fusion criteria (target transfusion > 10.0 g/dL or > 2 g/dL of target minus trigger level) were applied to examine the intraoperative factors with the intraoperative transfusion practice. Perioperative morbidity was further assessed based on the inappropriate transfusion and overtransfusion status.

Results

Intraoperative transfusion was used in 468 (31.1%) of the 1,506 patients included in the study. Among them, 212 (45.3%) intraoperative transfusion episodes were classified as inappropriate, and 135 cases (28.8%) were confirmed as overtransfusion. On univariate analysis, inappropriate transfusions were observed more commonly among patients with younger age (p < 0.001) and who underwent hepatic resection (p < 0.001) or intestinal resection (p < 0.001). Overtransfusion was also associated with elevated trigger of 8.0 g/dL Hb (p = 0.006) and younger age (p = 0.003). No perioperative complications were associated with inappropriate transfusions and overtransfusion under multivariate analysis.

Conclusions

Overtransfusion was common in hepatic resection and younger age, but to definitely prove this hypothesis, a prospective randomized trial needs to be performed.

Sublingual microcirculation does not reflect red blood cell transfusion thresholds in the intensive care unit-a prospective observational study in the intensive care unit

Purpose

Hemoglobin (Hb) transfusion thresholds are established in intensive care units. A restrictive transfusion threshold (Hb 70–75 g/l) is recommended in septic patients, and a liberal transfusion threshold (Hb 90 g/l) for cardiogenic shock. It is unclear whether these historically adopted transfusion thresholds meet the challenges of individual patients.

Methods

We evaluated microvascular flow index (MFI) and proportion of perfused vessels (PPV) in the sublingual microcirculation with CytoCam-IDF microscopy and near-infrared spectroscopy (NIRS). A study team-independent, treating intensivist assigned a total of 64 patients to 1 of 2 two transfusion thresholds, 43 patients to the Hb 75 g/l threshold and 21 patients to the Hb 90 g/l threshold, at a surgical intensive care unit. We performed microcirculatory measurements 1 h before and 1 h after transfusion of 1 unit of red blood cells.

Results

Microcirculatory flow variables correlated negatively with pre-transfusion flow variables (ΔMFI: ρ = − 0.821, p <  0.001; ΔPPV: ρ = − 0.778, p <  0.001). Patients with good initial microcirculation (cutoffs: MFI > 2.84, PPV > 88%) showed a deteriorated microcirculation after red blood cell transfusion. An impaired microcirculation improved after transfusion. At both transfusion thresholds, approximately one third of the patients showed an initially impaired microcirculation. In contrast, one third in every group had good microcirculation above the cutoff variables and did not profit from the transfusion.

Conclusion

The data suggest that the established transfusion thresholds and other hemodynamic variables do not reflect microcirculatory perfusion of patients. Blood transfusion at both thresholds 75 g/l and 90 g/l hemoglobin can either improve or harm the microcirculatory blood flow, questioning the concept of arbitrary transfusion thresholds.

Cost-effectiveness comparison of routine transfusion with restrictive and liberal transfusion strategies for surgical patients in China

BACKGROUND AND OBJECTIVES

A health industry standard recommending restrictive transfusion is to be in effect in China in April 2019. We aim to explore its potential economic and clinical impacts among surgical patients.

MATERIALS AND METHODS

A decision tree model was applied to compare cost-effectiveness of current routine transfusion in China, a restrictive (transfusion at Hb < 8 g/dl or ischaemic symptoms) and a liberal (transfusion at Hb < 10 g/dl) strategy. Parameters were estimated from empirical data of 25 227 surgical inpatients aged ≥30 years in a multicenter study and supplemented by meta-analysis when necessary. Results are shown for cardio-cerebral-vascular (CCV) surgery and non-CCV (orthopaedics, general, thoracic) surgery separately.

RESULTS

Per 10 000 patients in routine, restrictive, liberal transfusion scenarios, total spending (transfusion and length of stay related) was 7·67, 7·58 and 9·39 million CNY (1 CNY × 0.157 = 1 US dollar) for CCV surgery and 6·35, 6·70 and 8·09 million CNY for non-CCV surgery; infectious and severe complications numbered 354, 290, and 290 (CCV) and 315, 286, and 330 (non-CCV), respectively. Acceptability curves showed high probabilities for restrictive strategy to be cost-effective across a wide range of willingness-to-pay values. Such findings were mostly consistent in sensitivity and subgroup analyses except for patients with cardiac problems.

CONCLUSION

We showed strong rationale, succeeding previous findings only in cardiac or joint procedures, to comply with the new standard as restrictive transfusion has high potential to save blood, secure safety, and is cost-effective for a wide spectrum of surgical patients. Experiences should be further summarized to pave the way towards individualized transfusion.

Surgical prescription of epoetin alfa in contemporary total hip arthroplasty: a prospective comparative study

Purpose

Pre-operative anaemia treatment has been associated with reduced morbidity in joint arthroplasty. This study examined the impact of a surgical prescription of epoetin (EPO) in contemporary total hip arthroplasty (THA).

Methods

We conducted a comparative study in a series of 1402 primary THAs performed in patients all having a pre-operative haemoglobin (Hb) level documented four to eight  weeks before THA surgery. In group A (647 hips), one subcutaneous injection of 40,000 IU EPO once a week for four weeks was prescribed at the discretion of anaesthetist during the pre-operative visit in patients with pre-operative Hb between 10 and 13 g/dl. In group S comprising the remaining 755 hips, an amended EPO therapy including two  injections of 20,000 to 40,000 IU was prescribed by the surgeon in patients with Hb less than 12 g/dl deemed at high risks to be transfused following THA. Primary study endpoint was the bleeding index (BI).

Results

EPO therapy was delivered in 43 patients (6.7%) in group A and in 26 patients (3.4%) in group S (p = 0.006). The mean total dose of EPO administrated was 115,349 IU in group A versus 75,200 IU in group S (p < 0.001). The mean BI were 2.7 ± 1.0 in group A and 2.8 ± 1.0 g/dl in group S (p = 0.375). No patient was blood-transfused up to post-operative day seven in group S versus five patients in group A (p = 0.021).

Conclusions

The amended protocol does not lead to increased peri-operative bleeding. Advances in intra-operative methods to reduce the bleeding allow changing indications of EPO in patients undergoing THA with a low level of Hb.

Guidelines on the intraoperative transfusion of red blood cells: a protocol for systematic review

INTRODUCTION

A significant proportion of red blood cell (RBC) transfusions are administered intraoperatively; yet there is limited evidence to guide transfusion decisions in this setting. The objective of this systematic review is to explore the availability, quality and content of clinical practice guidelines (CPGs) reporting on the indication for allogenic RBC transfusion during surgery.

METHODS

Major electronic databases (MEDLINE, EMBASE and CINAHL), guideline clearinghouses and Google Scholar, will be systematically searched from inception to January 2019 for CPGs pertaining to indications for intraoperative allogenic RBC transfusion. Characteristics of eligible guidelines will be reported in a summary table. The AGREE II instrument will be used to appraise the quality of identified guidelines. Recommendations advising on indications for intraoperative RBC transfusion will be manually extracted and presented to allow for comparison of similarities and/or discrepancies in the literature.

ETHICS AND DISSEMINATION

The results of this systematic review will be disseminated through relevant conferences and peer-reviewed journals.

TRIAL REGISTRATION NUMBER

CRD42018111487.

Artificial Oxygen Carriers-Past, Present, and Future-a Review of the Most Innovative and Clinically Relevant Concepts

Blood transfusions are a daily practice in hospitals. Since these products are limited in availability and have various, harmful side effects, researchers have pursued the goal to develop artificial blood components for about 40 years. Development of oxygen therapeutics and stem cells are more recent goals. Medline (https://www.ncbi.nlm.nih.gov/pubmed/?holding=ideudelib), ClinicalTrials.gov (https://clinicaltrials.gov), EU Clinical Trials Register (https://www.clinicaltrialsregister.eu), and Australian New Zealand Clinical Trials Registry (http://www.anzctr.org.au) were searched up to July 2018 using search terms related to artificial blood products in order to identify new and ongoing research over the last 5 years. However, for products that are already well known and important to or relevant in gaining a better understanding of this field of research, the reader is punctually referred to some important articles published over 5 years ago. This review includes not only clinically relevant substances such as heme-oxygenating carriers, perfluorocarbon-based oxygen carriers, stem cells, and organ conservation, but also includes interesting preclinically advanced compounds depicting the pipeline of potential new products. In- depth insights into specific benefits and limitations of each substance, including the biochemical and physiologic background are included. "Fancy" ideas such as iron-based substances, O2 microbubbles, cyclodextranes, or lugworms are also elucidated. To conclude, this systematic up-to-date review includes all actual achievements and ongoing clinical trials in the field of artificial blood products to pursue the dream of artificial oxygen carrier supply. Research is on the right track, but the task is demanding and challenging.

Influence of factor XIII activity on post-operative transfusion in congenital cardiac surgery-A retrospective analysis

Objectives

Coagulation factor XIII (FXIII) plays a key role in fibrin clot stabilization—an essential process for wound healing following cardiothoracic surgery. However, FXIII deficiency as a risk for post-operative bleeding in pediatric cardiac surgery involving cardiopulmonary bypass (CPB) for congenital heart disease (CHD) is controversially discussed. Thus, as primary outcome measures, we analyzed the association of pre-operative FXIII activity and post-operative chest tube drainage (CTD) loss with transfusion requirements post-operatively. Secondary outcomes included the influence of cyanosis and sex on transfusion.

Methods

Our retrospective analysis (2009–2010) encompassed a single center series of 76 cardio-surgical cases with CPB (0–17 years, mean age 5.61 years) that were post-operatively admitted to our pediatric intensive care unit (PICU). The observational period was 48 hours after cardiac surgery. Blood cell counts and coagulation status, including FXIII activity were routinely performed pre- and post-operatively. The administered amount of blood products and volume expanders was recorded electronically, along with the amount of CTD loss. Uni- and multivariate logistic regression analysis was performed to calculate the associations (odds ratios) of variables with post-operative transfusion needs.

Results

FXIII activities remained stable following CPB surgery. There was no association of pre- and post-operative FXIII activities and transfusion of blood products or volume expanders in the first 48 hours after surgery. Similarly, FXIII showed no association with CTD loss. Cyanosis and female sex were associated with transfusion rates.

Conclusions

Although essentially involved in wound healing and clotting after surgery, FXIII activity does not serve as a valid predictor of post-operative transfusion need.

A retrospective analysis of the mixed venous oxygen saturation as the target for systemic blood flow control during cardiopulmonary bypass

Objectives:

The patient’s body surface area serves as the traditional reference for the determination of systemic blood flow during cardiopulmonary bypass (CPB). New strategies refer to different algorithms of oxygen delivery. This study reports on the mixed venous oxygen saturation (SvO2) as the target for systemic blood flow control. We hypothesise that an SvO2>75% (SvO275) is associated with better preservation of renal function and improved short-term survival.

Methods:

This retrospective, 10-year, observational study analysed 6945 consecutive cardiac surgical cases requiring CPB. Endpoints included rates of acute kidney injury (AKI) and short-term survival, also the estimated glomerular filtration rate (eGFR), lactate levels and blood transfusions.

Results:

Seventy-seven percent of the patients attained the SvO275 target. For this group, the median SvO2 was 78.1 (5.8) %, with a mean oxygen delivery of 331 (78) ml/min per m2 body surface area. Overall incidence of AKI levels (I-III): 7.5% - 2.6% - 0.6%. Incidence of eGFR (<50%): 3.9%, increasing to 6% for haemoglobin levels <80 g/L (p<0.001). Red cell transfusion was more frequent (p<0.001) within this group (30.6%) compared to levels >100 g/L (0.3%). Further, women (52.8%) were transfused more often than men (14.6%). Lactate level at weaning from CPB was 1.3 (0.7) mmol/L. The SvO275 target demonstrated a relative risk reduction of 22.5% (p=0.032) for AKI (I), increasing to 32.3% (p=0.026) for procedures extending >90 minutes. In addition, the risk for death 90-days postop was lower (p=0.039).

Conclusion:

The SvO275 target showed a decreased risk for postoperative AKI and prolonged short-term survival. Good clinical outcomes were also linked to measures of lactate and the eGFR. However, anaemia remains a risk factor for AKI.

Blood Product Administration in the Critical Care and Perioperative Settings

The critical care and perioperative settings are high consumers of blood products, with multiple units and different products often given to an individual patient. The recommendation of this review is always to consider the risks and benefits for a specific blood product for a specific patient in a specific clinical setting. Optimize patient status by treating anemia and preventing the need for red blood cell transfusion. Consider other options for correction of anemia and coagulation disorders and use an imperative non-overtransfusion policy for all blood products.

The effects of storage of red blood cells on the development of postoperative infections after noncardiac surgery

BACKGROUND

Prolonged storage of red blood cells (RBCs) is a potential risk factor for postoperative infections. The objective of this study was to examine the effect of age of RBCs transfused on development of postoperative infection.

STUDY DESIGN AND METHODS

In this prospective, double-blind randomized trial, 199 patients undergoing elective noncardiac surgery and requiring RBC transfusion were assigned to receive nonleukoreduced RBCs stored for not more than 14 days ("fresh blood" group, n = 101) or for more than 14 days ("old blood" group, n = 98). The primary outcome was occurrence of infection within 28 days after surgery; secondary outcomes were postoperative acute kidney injury (AKI), in-hospital and 90-day mortality, admission to intensive care unit, and hospital length of stay (LOS). As older blood was not always available, an "as-treated" (AT) analysis was also performed according to actual age of the RBCs transfused.

RESULTS

The median [interquartile range] storage time of RBCs was 6 [5-10] and 15 [11-20] days in fresh blood and in old blood groups, respectively. The occurrence of postoperative infection did not differ between groups (fresh blood 22% vs. old blood 25%; relative risk [RR], 1.17; confidence interval [CI], 0.71-1.93), although wound infections occurred more frequently in old blood (15% vs. 5%; RR, 3.09; CI, 1.17- 8.18). Patients receiving older units had a higher rate of AKI (24% vs. 6%; p < 0.001) and, according to AT analysis, longer LOS (mean difference, 3.6 days; CI, 0.6-7.5).

CONCLUSION

Prolonged RBC storage time did not increase the risk of postoperative infection. However, old blood transfusion increased wound infections rate and incidence of AKI.

Hemoglobin concentrations and RBC transfusion thresholds in patients with acute brain injury: an international survey

Background

The optimal hemoglobin (Hb) threshold at which to initiate red blood cell (RBC) transfusion in patients with acute brain injury is unknown. The aim of this survey was to investigate RBC transfusion practices used with these patients.

Methods

We conducted a web-based survey within various societies of critical care medicine for intensive care unit (ICU) physicians who currently manage patients with primary acute brain injury.

Results

A total of 868 responses were obtained from around the world, half of which (n = 485) were from European centers; 204 (24%) respondents had a specific certificate in neurocritical care, and most were specialists in anesthesiology or intensive care and had less than 15 years of practice experience. Four hundred sixty-six respondents (54%) said they used an Hb threshold of 7–8 g/dl to initiate RBC transfusion after acute brain injury, although half of these respondents used a different threshold (closer to 9 g/dl) in patients with traumatic brain injury, subarachnoid hemorrhage, or ischemic stroke. Systemic and cerebral factors were reported as influencing the need for higher Hb thresholds. Most respondents agreed that a randomized clinical trial was needed to compare two different Hb thresholds for RBC transfusion, particularly in patients with traumatic brain injury, subarachnoid hemorrhage, and ischemic stroke.

Conclusions

The Hb threshold used for RBC transfusion after acute brain injury was less than 8 g/dl in half of the ICU clinicians who responded to our survey. However, more than 50% of these physicians used higher Hb thresholds in certain conditions.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-017-1748-4) contains supplementary material, which is available to authorized users.

Development of Multivariable Models to Predict and Benchmark Transfusion in Elective Surgery Supporting Patient Blood Management

BACKGROUND

Blood transfusion is a highly prevalent procedure in hospitalized patients and in some clinical scenarios it has lifesaving potential. However, in most cases transfusion is administered to hemodynamically stable patients with no benefit, but increased odds of adverse patient outcomes and substantial direct and indirect cost. Therefore, the concept of Patient Blood Management has increasingly gained importance to pre-empt and reduce transfusion and to identify the optimal transfusion volume for an individual patient when transfusion is indicated.

OBJECTIVES

It was our aim to describe, how predictive modeling and machine learning tools applied on pre-operative data can be used to predict the amount of red blood cells to be transfused during surgery and to prospectively optimize blood ordering schedules. In addition, the data derived from the predictive models should be used to benchmark different hospitals concerning their blood transfusion patterns.

METHODS

6,530 case records obtained for elective surgeries from 16 centers taking part in two studies conducted in 2004-2005 and 2009-2010 were analyzed. Transfused red blood cell volume was predicted using random forests. Separate models were trained for overall data, for each center and for each of the two studies. Important characteristics of different models were compared with one another.

RESULTS

Our results indicate that predictive modeling applied prior surgery can predict the transfused volume of red blood cells more accurately (correlation coefficient cc = 0.61) than state of the art algorithms (cc = 0.39). We found significantly different patterns of feature importance a) in different hospitals and b) between study 1 and study 2.

CONCLUSION

We conclude that predictive modeling can be used to benchmark the importance of different features on the models derived with data from different hospitals. This might help to optimize crucial processes in a specific hospital, even in other scenarios beyond Patient Blood Management.

Physiologic correlates of intraoperative blood transfusion among patients undergoing major gastrointestinal operations

BACKGROUND

Guidelines for transfusion focus on nadir levels of hemoglobin. Hemoglobin triggers may not be helpful, however, in defining appropriate intraoperative use of packed red blood cells. We sought to define the use of intraoperative packed red blood cells relative to quantitative physiologic factors at the time of operation.

METHODS

Prospective intraoperative data on patients undergoing a major gastrointestinal operation between 2010 and 2014 were analyzed. Risk of intraoperative transfusion was assessed with multivariable extended Cox models using baseline clinical covariates and time-varying intraoperative covariates.

RESULTS

Among 2,316 patients, the mean preoperative hemoglobin was 12.6 g/dL (standard deviation = 2.0 g/dL), while the median estimated blood loss was 200 mL (interquartile range: 100-55 mL). Overall, 357 (15.4%) patients received a transfusion intraoperatively. A greater hazard of transfusion was associated with a greater American Society of Anesthesiologists class (ref: American Society of Anesthesiologists class I-II; American Society of Anesthesiologists class III-IV; hazard ratio = 1.44, 95% confidence interval, 1.18-1.77, P < .001), and a lesser preoperative hemoglobin level (per 1 g/dL increase; hazard ratio = 0.70, 95% confidence interval, 0.65-0.74, P < .001). In addition, an increase in heart rate of 10 beats/min above the cumulative average at any measurement was associated with up to a 30% increased probability of transfusion (hazard ratio = 1.30, 95% confidence interval, 1.15-1.47, P < .001); similarly, an increase in mean arterial pressure of 10 mm Hg was associated with an 8% decreased likelihood of transfusion (hazard ratio = 0.92, 95% confidence interval, 87-0.99, P = .017). In contrast, nadir hemoglobin was not associated with the risk of receiving a transfusion (hazard ratio = 1.10, 95% confidence interval, 0.97-1.23, P = .129). Among patients who received an intraoperative transfusion, 9.2% (n = 33) never had a hemoglobin nadir below 10 g/dL, nor an average mean arterial pressure less than 65 mm Hg or a heart rate greater than 100 beats/min around the time of transfusion.

CONCLUSION

Among the intraoperative factors, heart rate, and mean arterial pressure were strongly associated with the likelihood of receiving a transfusion, despite the observation that 9.2% of patients never had a physiologic indicator for transfusion or a nadir hemoglobin below 10 g/dL, suggesting a subset of patients could benefit from a decrease in intraoperative rate of transfusion.

Administration Safety of Blood Products - Lessons Learned from a National Registry for Transfusion and Hemotherapy Practice

BACKGROUND

Compared to blood component safety, the administration of blood may not be as safe as intended. The German Interdisciplinary Task Force for Clinical Hemotherapy (IAKH) specialized registry for administration errors of blood products was chosen for a detailed analysis of reports.

METHODS

Voluntarily submitted critical incident reports (n = 138) from 2009 to 2013 were analyzed.

RESULTS

Incidents occurred in the operation room (34.1%), in the ICU (25.2%), and in the peripheral ward (18.5%). Procedural steps with errors were administration to the patient (27.2%), indication and blood order (17.1%), patient identification (17.1%), and blood sample withdrawal and tube labeling (18.0%). Bedside testing (BST) of blood groups avoided errors in only 2.6%. Associated factors were routine work conditions (66%), communication error (36%), emergency case (26%), night or weekend team (39%), untrained personnel (19%). Recommendations addressed process and quality (n = 479) as well as structure quality (n = 314). In 189 instances, an IT solution would have helped to avoid the error.

CONCLUSIONS

The administration process is prone to errors at the patient assessment for the need to transfuse and the application of blood products to patients. BST is only detecting a minority of handling errors. According to the expert recommendations for practice improvement, the potential to improve transfusion safety by a technical solution is considerable.

Gender disparities in red blood cell transfusion in elective surgery: a post hoc multicentre cohort study

OBJECTIVES

A post hoc gender comparison of transfusion-related modifiable risk factors among patients undergoing elective surgery.

SETTINGS

23 Austrian centres randomly selected and stratified by region and level of care.

PARTICIPANTS

We consecutively enrolled in total 6530 patients (3465 women and 3065 men); 1491 underwent coronary artery bypass graft (CABG) surgery, 2570 primary unilateral total hip replacement (THR) and 2469 primary unilateral total knee replacement (TKR).

MAIN OUTCOME MEASURES

Primary outcome measures were the number of allogeneic and autologous red blood cell (RBC) units transfused (postoperative day 5 included) and differences in intraoperative and postoperative transfusion rate between men and women. Secondary outcomes included perioperative blood loss in transfused and non-transfused patients, volume of RBCs transfused, perioperative haemoglobin values and circulating red blood volume on postoperative day 5.

RESULTS

In all surgical groups, the transfusion rate was significantly higher in women than in men (CABG 81 vs 49%, THR 46 vs 24% and TKR 37 vs 23%). In transfused patients, the absolute blood loss was higher among men in all surgical categories while the relative blood loss was higher among women in the CABG group (52.8 vs 47.8%) but comparable in orthopaedic surgery. The relative RBC volume transfused was significantly higher among women in all categories (CABG 40.0 vs 22.3; TKR 25.2 vs 20.2; THR 26.4 vs 20.8%). On postoperative day 5, the relative haemoglobin values and the relative circulating RBC volume were higher in women in all surgical categories.

CONCLUSIONS

The higher transfusion rate and volume in women when compared with men in elective surgery can be explained by clinicians applying the same absolute transfusion thresholds irrespective of a patient's gender. This, together with the common use of a liberal transfusion strategy, leads to further overtransfusion in women.

Blood transfusion and coagulation management

Despite impressive progress in surgical technique, aortic surgery is still associated with relatively high morbidity and mortality. One of the most important contributors to this phenomenon is the triad of bleeding, anemia, and transfusion. All three factors are known to influence the outcome of aortic surgery to a great extent. However, over the last few years a multidisciplinary, multimodal concept has been established, which enables the physician to avoid bleeding, anemia, and transfusion as much as possible. The concept of "patient blood management" combines several established measures with the potential to improve perioperative outcome. This chapter describes these measures with regard to aortic surgery and assesses their respective efficacy.