Red blood cell transfusion in critically ill children: a narrative review

Safety of bloodless open-heart surgery on cardiopulmonary bypass in selected children: A single center experience with minimal invasive extracorporeal circulation

INTRODUCTION

Bloodless cardiac surgery refers to open-heart surgery without blood or blood products. The cardiopulmonary bypass (CPB) circuits are primed with crystalloid solely, and there is no intraoperative blood transfusion.

METHODS

Our program considers bloodless congenital cardiac surgery with a minimal invasive extracorporeal circulation (MiECC) system for patients above 10 kg of weight. We performed a single-center retrospective cohort study of all consecutive patients undergoing bloodless cardiac surgery for congenital heart defects between January 2016 and December 2018.

RESULTS

A total of 164 patients were reviewed (86 male and 78 female) at a median age of 9.6 years (interquartile range (IQR), 4.5-15), a weight of 32 kg (IQR, 16-55), preoperative hemoglobin 13.7 g/dl (IQR, 12.6-14.9), and preoperative hematocrit of 40.4% (IQR, 37.2-44.3). Median CPB time was 81.5 min (IQR, 58-125), and median hematocrit coming off CPB was 26% (IQR, 23-29.7). The congenital heart surgery risk (STAT) category was distributed in STAT 1 for 70, STAT 2 for 80, STAT 3 for 9, and STAT 4 for 5 patients. Most patients (95%) were extubated in the operating room with a low complication rate during the hospital stay (14.6%). Only 6 (4%) patients needed a blood transfusion during the postoperative period, with a higher incidence of complications during the hospital course (p < 0.001).

CONCLUSIONS

Bloodless congenital heart surgery with MiECC system is safe in low-surgical-risk patients. Our patients had a low rate of complications and short hospital stays.

Elevated international normalized ratio is correlated with large volume transfusion in pediatric trauma patients

BACKGROUND

Pediatric trauma patients may benefit from a balanced transfusion strategy, however, determining when to activate massive transfusion protocols remains uncertain. The purpose of this study was to explore whether certain scoring systems can predict the need for large volume transfusion.

METHODS

We conducted a retrospective review of pediatric trauma patients who presented to our center and required a transfusion of packed red blood cells. Baseline laboratory and clinical data were used to calculate Trauma Associated Severe Hemorrhage (TASH) score and a previously reported composite of acidosis and coagulopathy.

RESULTS

We identified 518 pediatric trauma patients who presented to our center between January 1, 2013 and December 31, 2018. These patients were less than 18 years of age (mean 9.6 years) and had an injury severity score ranging from 1 to 50 (mean 11.3). Forty-three patients (8.3%) received a transfusion within 24 hours of presentation, ranging from 4 to 139 mL/kg of packed red blood cells (mean 23.1 mL/kg). Transfusion volume was associated with acidosis and coagulopathy scores (r = 0.37, p = 0.033) and international normalized ratio (INR) (r = 0.34, p = 0.03) but not TASH (p = 0.72). Patients with INR≥1.3 received a higher mean volume of packed red cells compared to those with normal values (34 versus 18 mL/kg, p = 0.046).

CONCLUSION

Pediatric trauma patients who undergo transfusion of packed red blood cells are likely to require large volume transfusion if their baseline INR is ≥1.3. These patients may benefit from a balanced transfusion strategy, such as utilization of massive transfusion protocols or whole blood.

Cell saver blood transfusions may be associated with a decrease in inflammation and improved outcome measures in pediatric cardiac surgery patients

OBJECTIVE

Cardiopulmonary bypass (CPB) is a requisite for correction of congenital heart disease by open-heart surgery and induces a systemic inflammatory response that can lead to complications such as acute lung injury and acute kidney injury. In addition, blood transfusions are commonly required for this type of surgery, and they may further exacerbate this inflammatory response and increase morbidity and mortality. We hypothesized that, in contrast to red blood cells, intraoperative cell saver (CS) blood transfusions attenuate the post-CPB proinflammatory cytokine response.

METHODS

Serum cytokine concentrations of IL-10, IL-1RA, IL-6, IL-8, and TNF-α were measured at four time points (preoperatively and postoperatively on postoperative days 0, 1, and 2).

RESULTS

Anti-inflammatory IL-10 levels were significantly lower in the CS group on POD 0 than in the control group (mean 1083.2 pg/mL vs 2080.2 pg/mL, 95%CI 357.4-1636.6, p = .0026). Of the clinical parameters measured, mean BUN and creatinine levels on POD 2 were significantly lower in the CS group (13.79 vs 21.88, p = .004 and 0.45 vs 0.55, p = .055, respectively). In addition, the duration of milrinone use decreased by 80% in the CS group (0.20, 95%CI 0.04, 0.94; p = .048), the median time to extubation in hours was significantly lower in the CS group (3.5 vs 6.5; 95%CI -38.00, -0.50; p = .026), and hospital length of stay was decreased by 60% in the CS group (p = .003).

CONCLUSIONS

CS transfusions in children may lower postoperative anti-inflammatory IL-10 levels, possibly due to an overall decrease in proinflammatory state, and may be associated with improvements in renal and pulmonary functions.

Independent Risk Factors for RBC Transfusion in Children Undergoing Surgery. Analysis of 14,248 Cases at a German University Hospital

Background: paediatric patients are vulnerable to blood loss and even a small loss of blood can be associated with severe shock. In emergency situations, a red blood cell (RBC) transfusion may become unavoidable, although it is associated with various risks. The aim of this trial was to identify independent risk factors for perioperative RBC transfusion in children undergoing surgery. Methods: to identify independent risk factors for perioperative RBC transfusion in children undergoing surgery and to access RBC transfusion rates and in-hospital outcomes (e.g., length of stay, mortality, and typical postoperative complication rates), a monocentric, retrospective, and observational study was conducted. Descriptive, univariate, and multivariate analyses were performed. Results: between 1 January 2010 and 31 December 2019, data from n = 14,248 cases were identified at the centre. Analysis revealed an RBC transfusion rate of 10.1% (n = 1439) in the entire cohort. The independent predictors of RBC transfusion were the presence of preoperative anaemia (p < 0.001; OR = 15.10 with preoperative anaemia and OR = 2.40 without preoperative anaemia), younger age (p < 0.001; ORs between 0.14 and 0.28 for children older than 0 years), female gender (p = 0.036; OR = 1.19 compared to male gender), certain types of surgery (e.g., neuro surgery (p < 0.001; OR = 10.14), vascular surgery (p < 0.001; OR = 9.93), cardiac surgery (p < 0.001; OR = 4.79), gynaecology (p = 0.014; OR = 3.64), visceral surgery (p < 0.001; OR = 2.48), and the presence of postoperative complications (e.g., sepsis (p < 0.001; OR = 10.16), respiratory dysfunction (p < 0.001; OR = 7.56), cardiovascular dysfunction (p < 0.001; OR = 4.68), neurological dysfunction (p = 0.029; OR = 1.77), and renal dysfunction (p < 0.001; OR = 16.17)). Conclusion: preoperative anaemia, younger age, female gender, certain types of surgery, and postoperative complications are independent predictors for RBC transfusion in children undergoing surgery. Future prospective studies are urgently required to identify, in detail, the potential risk factors and impact of RBC transfusion in children.

Changes in Transfusion Practice in Children and Adolescents over Time

Introduction

In recent years, resource-saving handling of allogeneic blood products and a reduction of transfusion rates in adults has been observed. However, comparable published national data for transfusion practices in pediatric patients are currently not available. In this study, the transfusion rates for children and adolescents were analyzed based on data from the Federal Statistical Office of Germany during the past 2 decades.

Methods

Data were queried via the database of the Federal Statistical Office (Destasis). The period covered was from 2005 to 2018, and those in the sample group were children and adolescents aged 0-17 years receiving inpatient care. Operation and procedure codes (OPS) for transfusions, procedures, or interventions with increased transfusion risk were queried and evaluated in detail.

Results

In Germany, 0.9% of the children and adolescents treated in hospital received a transfusion in 2018. A reduction in transfusion rates from 1.02% (2005) to 0.9% (2018) was observed for the total collective of children and adolescents receiving inpatient care. Increases in transfusion rates were recorded for 1- to 4- (1.41-1.45%) and 5- to 10-year-olds (1.24-1.33%). Children under 1 year of age were most frequently transfused (in 2018, 40.2% of the children were cared for in hospital). Transfusion-associated procedures such as chemotherapy or machine ventilation and respiratory support for newborns and infants are on the rise.

Conclusion

Transfusion rates are declining in children and adolescents, but the reasons for increases in transfusion rates in other groups are unclear. Prospective studies to evaluate transfusion rates and triggers in children are urgently needed.

Changes in transfusion and fluid therapy practices in severely injured children: an analysis of 5118 children from the TraumaRegister DGU®

Purpose

Trauma is the leading cause of death in children. In adults, blood transfusion and fluid resuscitation protocols changed resulting in a decrease of morbidity and mortality over the past 2 decades. Here, transfusion and fluid resuscitation practices were analysed in severe injured children in Germany.

Methods

Severely injured children (maximum Abbreviated Injury Scale (AIS) ≥ 3) admitted to a certified trauma-centre (TraumaZentrum DGU®) between 2002 and 2017 and registered at the TraumaRegister DGU® were included and assessed regarding blood transfusion rates and fluid therapy.

Results

5,118 children (aged 1–15 years) with a mean ISS 22 were analysed. Blood transfusion rates administered until ICU admission decreased from 18% (2002–2005) to 7% (2014–2017). Children who are transfused are increasingly seriously injured. ISS has increased for transfused children aged 1–15 years (2002–2005: mean 27.7–34.4 in 2014–2017). ISS in non-transfused children has decreased in children aged 1–15 years (2002–2005: mean 19.6 to mean 17.6 in 2014–2017). Mean prehospital fluid administration decreased from 980 to 549 ml without affecting hemodynamic instability.

Conclusion

Blood transfusion rates and amount of fluid resuscitation decreased in severe injured children over a 16-year period in Germany. Restrictive blood transfusion and fluid management has become common practice in severe injured children. A prehospital restrictive fluid management strategy in severely injured children is not associated with a worsened hemodynamic state, abnormal coagulation or base excess but leads to higher hemoglobin levels.

Standardized Implementation of Evidence-based Guidelines to Decrease Blood Transfusions in Pediatric Intensive Care Units

Introduction

Despite evidence that red blood cell (RBC) transfusions may be associated with more harm than benefit, current transfusion practices vary significantly. This multicenter, quality improvement study aimed to sustainably decrease the rate of RBC transfusions in pediatric intensive care units (PICUs).

Methods

This 16-month prospective study included 5 PICUs. We implemented a standardized project plan including education, bedside tools, real-time reminders, and email feedback. We collected data from consecutive transfusions during pre-implementation (Phase I), postimplementation (Phase II), and post-stabilization phases (Phase III).

Results

Of the 2,064 RBC transfusions, we excluded 35% (N = 729) from analysis in patients undergoing extracorporeal membrane oxygenation. Transfusion/1,000 admissions improved throughout the study periods from a baseline 209.6 -199.8 in Phase II and 195.8 in Phase III (P value < 0.05). There were fewer transfusions outside of the hemoglobin threshold guideline, decreasing from 81% of transfusions outside of guidelines in Phase I to 74% in Phases II and III, P < 0.05. Study phase, site, co-management status, service of requesting provider, admit reason, previous transfusion status, and age were associated with transfusion above guideline threshold.

Conclusions

Multicenter collaboration can successfully deploy a standardized plan that adheres to implementation science principles to sustainably decrease the rate of RBC transfusion outside of guideline thresholds. However, we did not decrease the total number of transfusions in our study. The complexity of multiple specialties co-managing patients is common in the contemporary PICU. Educational initiatives aimed at one specialty may have limited effectiveness in a multifaceted system of care.

Recommendations on RBC Transfusion in General Critically Ill Children Based on Hemoglobin and/or Physiologic Thresholds From the Pediatric Critical Care Transfusion and Anemia Expertise Initiative

OBJECTIVES

To present the consensus recommendations and supporting literature for RBC transfusions in general critically ill children from the Pediatric Critical Care Transfusion and Anemia Expertise Initiative.

DESIGN

Consensus conference series of international, multidisciplinary experts in RBC transfusion management of critically ill children.

METHODS

The panel of 38 experts developed evidence-based and, when evidence was lacking, expert-based recommendations and research priorities regarding RBC transfusions in critically ill children. The subgroup on RBC transfusion in general critically ill children included six experts. Electronic searches were conducted using PubMed, EMBASE, and Cochrane Library databases from 1980 to May 30, 2017, using a combination of keywords to define concepts of RBC transfusion and critically ill children. Recommendation consensus was obtained using the Research and Development/UCLA Appropriateness Method. The results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method.

RESULTS

Three adjudicators reviewed 4,399 abstracts; 71 papers were read, and 17 were retained. Three papers were added manually. The general Transfusion and Anemia Expertise Initiative subgroup developed, and all Transfusion and Anemia Expertise Initiative members voted on two good practice statements, six recommendations, and 11 research questions; in all instances, agreement was reached (> 80%). The good practice statements suggest a framework for RBC transfusion in PICU patients. The good practice statements and recommendations focus on hemoglobin as a threshold and/or target. The research questions focus on hemoglobin and physiologic thresholds for RBC transfusion, alternatives, and risk/benefit ratio of transfusion.

CONCLUSIONS

Transfusion and Anemia Expertise Initiative developed pediatric-specific good practice statements and recommendations regarding RBC transfusion management in the general PICU population, as well as recommendations to guide future research priorities. Clinical recommendations emphasized relevant hemoglobin thresholds, and research recommendations emphasized a need for further understanding of physiologic thresholds, alternatives to RBC transfusion, and hemoglobin thresholds in populations with limited pediatric literature.

Pediatric red cell and platelet transfusions

The aim of pediatric transfusions should be based on the concept of avoiding unnecessary transfusions without jeopardizing the patient safety and providing correct blood components when there are well founded indications to transfuse. Despite considerable efforts from transfusion services to increase transfusion safety, transfusions are still associated with preventable and unpreventable adverse effects that may, in the worst case, have severe and fatal consequences. Transfusions to pediatric patients constitute a small proportion of all transfusions but have higher incidence of adverse events compared to adults. Pediatric transfusions consist of intrauterine transfusions, top-up transfusions to neonates and young children, exchange transfusions in the management of hemolytic disease of newborn (HDN), in addition to sickle cell crisis, chronic transfusion therapy in thalassemia patients, massive transfusion in trauma, HLA- and HPA-compatible platelets in immunized patients and neonates with fetal neonatal alloimmune thrombocytopenia (FNAIT). Packed red cells (PRCs) and platelet (PLT) concentrates are the most utilized blood components and will be reviewed here.

Transfusion-related immunomodulation: review of the literature and implications for pediatric critical illness

Transfusion-related immunomodulation (TRIM) in the intensive care unit (ICU) is difficult to define and likely represents a complicated set of physiologic responses to transfusion, including both proinflammatory and immunosuppressive effects. Similarly, the immunologic response to critical illness in both adults and children is highly complex and is characterized by both acute inflammation and acquired immune suppression. How transfusion may contribute to or perpetuate these phenotypes in the ICU is poorly understood, despite the fact that transfusion is common in critically ill patients. Both hyperinflammation and severe immune suppression are associated with poor outcomes from critical illness, underscoring the need to understand potential immunologic consequences of blood product transfusion. In this review we outline the dynamic immunologic response to critical illness, provide clinical evidence in support of immunomodulatory effects of blood product transfusion, review preclinical and translational studies to date of TRIM, and provide insight into future research directions.

Validity of non-invasive point-of-care hemoglobin estimation in healthy and sick children-a method comparison study

This study was conducted at a tertiary care center in northern India to evaluate the validity of non-invasive transcutaneous hemoglobin estimation in healthy and sick children in comparison to hemoglobin estimation by traditional lab method. A method comparison study was conducted including 150 subjects. Enrolled patients included 80 neonates with average age of 3.9 ± 2.1 days, and 70 children with average age of 5.8 ± 2 years. Each population (newborn and children) comprised of almost equal numbers of healthy and critically ill patients with shock. Hemoglobin (Hb) was estimated on enrolment by transcutaneous spectrophotometry (SpHb) and traditional automated lab analyzer (Hb-Lab). Difference between Hb levels by the two methods (called bias) was measured and analyzed using Bland-Altman method. Out of 148 data pairs analyzed, bias between SpHb and Hb-Lab was -1.52 ± 1.91 g/dl (mean ± SD). SpHb showed excellent positive correlation with Hb-Lab (r = 0.94 (p < 0.001)) and good visual agreement on Bland-Altman plots. Bias was higher in sick subjects with shock as compared to healthy ones in both neonatal and pediatric population (-2.31 ± 2.21 g/dl versus -0.77 ± 1.2 g/dl, respectively).

CONCLUSIONS

SpHb showed good accuracy and correlated well with lab estimated Hb levels in healthy children. However, in children with impaired peripheral perfusion, its diagnostic accuracy was inadequate to justify routine use for quantification of severity of anemia and making transfusion decisions solely on non-invasive estimation of hemoglobin.

WHAT IS KNOWN

Non-invasive hemoglobin estimation is a relatively new and novel method which has given mixed results regarding its potential efficacy in adults. There is limited data regarding usefulness and accuracy of non-invasive Hb estimation by SpHb in sick neonates and children.

WHAT IS NEW

Non-invasive Hb estimation by SpHb monitor is reasonably accurate in healthy neonates and children. It can be used in critically ill children and neonates, but in conjunction with lab confirmation of Hb values.

Association of postoperative furosemide use with a reduced blood transfusion rate in sagittal craniosynostosis surgery

OBJECT A major challenge in sagittal craniosynostosis surgery is the high transfusion rate (50%-100%) related to blood loss in small pediatric patients. Several approaches have been proposed to prevent packed red blood cell (PRBC) transfusion, including endoscopic surgery, erythropoietin ortranexamic acid administration, and preoperative hemodilution. The authors hypothesized that a significant proportion of postoperative anemia observed in pediatric patients is actually dilutional. Consequently, since 2005, at CHU Sainte-Justine, furosemide has been administered to correct the volemic status and prevent PRBC transfusion. The purpose of this study was to evaluate the impact of postoperative furosemide administration on PRBC transfusion rates. METHODS This was a retrospective study of 96 consecutive patients with sagittal synostosis who underwent surgery at CHU Sainte-Justine between January 2000 and May 2012. The mean age at surgery was 4.9 ± 1.5 months (range 2.8-8.7 months). Patients who had surgery before 2005 constituted the control group. Those who had surgery in 2005 or 2006 were considered part of an implementation phase because furosemide administration was not routine. Patients who had surgery after 2006 were part of the experimental (or furosemide) group. Transfusion rates among the 3 groups were compared. The impact of furosemide administration on transfusion requirement was also measured while accounting for other variables of interest in a multiple logistic regression model. RESULTS The total transfusion rate was significantly reduced in the furosemide group compared with the control group (31.3% vs 62.5%, respectively; p = 0.009), mirroring the decrease in the postoperative transfusion rate between the groups (18.3% vs 50.0%, respectively; p = 0.003). The postoperative transfusion threshold remained similar throughout the study (mean hemoglobin 56.0 g/dl vs 60.9 g/dl for control and furosemide groups, respectively; p = 0.085). The proportion of nontransfused patients with recorded hemoglobin below 70 g/dl did not differ between the control and furosemide groups (41.7% vs 28.6%, respectively; p = 0.489). Surgical procedure, preoperative hemoglobin level, estimated blood loss, and furosemide administration significantly affected the risk of receiving a postoperative PRBC transfusion. When these variables were analyzed in a multiple logistic regression model, furosemide administration remained strongly associated with a reduced risk of being exposed to a blood transfusion (OR 0.196, p = 0.005). There were no complications related to furosemide administration. CONCLUSIONS A significant part of the postoperative anemia observed in patients who underwent sagittal craniosynostosis surgery was due to hypervolemic hemodilution. Correction of the volemic status with furosemide administration significantly reduces postoperative PRBC transfusion requirements in these patients.

Blood storage duration and morbidity and mortality in children undergoing cardiac surgery. A retrospective analysis

BACKGROUND

Blood transfusion is frequently required in children undergoing cardiac surgery and is associated with altered postoperative outcome. This may be due to alterations in red blood cell properties related to the storage process.

OBJECTIVE

To evaluate the effect of blood storage duration on postoperative morbidity and mortality in children undergoing cardiac surgery.

DESIGN

A retrospective review of a paediatric cardiac surgery database.

SETTING

Department of Anaesthesiology, Queen Fabiola Children's University Hospital, Brussels, Belgium.

PARTICIPANTS

Children transfused with one or two units of blood in the perioperative period.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Storage duration was used to allocate children to the Group 'Young' or the Group 'Old' (cut-off = 7 days). The primary endpoint was a composite based on the incidence of hospital mortality and/or the incidence of at least one organ failure.

RESULTS

From 1014 children in the database, 570 were included in the final analysis. One hundred and eighteen patients were included in the Group 'Young' [median (interquartile range, IQR) storage duration 6 (5 to 7) days] and 452 in the Group 'Old' [storage duration 14 (11 to 19) days]. No difference was found in mortality, length of ICU stay, mechanical ventilation duration, postoperative infection and major organ dysfunction. Duration of storage used as a continuous variable did not influence the incidence of the composite endpoint when evaluated by univariate or multivariate logistic regression analyses.

CONCLUSION

Red blood cell storage duration did not influence postoperative morbidity and mortality in paediatric cardiac surgery patients transfused with one or two units of blood.

Transfusion therapy in paediatric trauma patients: a review of the literature

Haemorrhage is a leading cause of death in paediatric trauma patients. Predefined massive transfusion protocols (MTP) have the potential to significantly reduce mortality by treating haemorrhagic shock and coagulopathy, in adhering to the principles of haemostatic resuscitation with rapid administration of balanced ratios of packed red blood cells (RBC), fresh frozen plasma (FFP) and platelets (PLT).

Because of their substantial physiological reserve, initial vital signs may not be good predictors of early haemorrhage in paediatric patients. Determining the triggers for MTP activation in paediatric trauma patients is challenging, and the optimal blood product ratio that will increase survival in massively bleeding paediatric trauma patients has yet to be determined. To date, only a few small descriptive studies and case reports have investigated the use of predefined MTP in paediatric trauma patients.

MTP with increased FFP or PLT to RBC ratios combined with viscoelastic haemostatic assay (VHA) guided haemostatic resuscitation have not yet been tested in paediatric populations but based on results from adult trauma patients, this therapeutic approach seems promising.

Considering the high prevalence of early coagulopathy in paediatric trauma patients, immediate identification and implementation of VHA-directed treatment of traumatic coagulopathy could ensure faster haemostasis and thereby, potentially, reduce bleeding as well as the total transfusion requirements and further improve outcome in paediatric trauma patients. Prospective randomized trials investigating this therapeutic approach in paediatric trauma patients are highly warranted.

The use of an extracorporeal membrane oxygenation anticoagulation laboratory protocol is associated with decreased blood product use, decreased hemorrhagic complications, and increased circuit life

OBJECTIVES

To determine if a comprehensive extracorporeal membrane oxygenation anticoagulation monitoring protocol results in fewer hemorrhagic complications, reduced blood product usage, and increased circuit life.

DESIGN

In September 2011, we augmented our standard extracorporeal membrane oxygenation laboratory protocol to include anti-factor Xa assays, thromboelastography, and antithrombin measurements. We performed a retrospective chart review to determine outcomes for patients placed on extracorporeal membrane oxygenation prior to and after the initiation of our anticoagulation laboratory protocol.

SETTING

Tertiary care, academic children's hospital.

PATIENTS

All patients who were placed on extracorporeal membrane oxygenation at our institution from January 1, 2007, to September 30, 2013.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

There were 261 extracorporeal membrane oxygenation runs before the initiation of the protocol and 105 extracorporeal membrane oxygenation runs after the initiation of the protocol. There were no major changes to our extracorporeal membrane oxygenation circuit or changes to our transfusion threshold during the study period. The indication for extracorporeal membrane oxygenation, age, and severity of illness of the patients were similar before and after protocol initiation. Median blood product usage for packed RBCs, fresh frozen plasma, platelets, and cryoprecipitate decreased significantly after protocol initiation. The occurrence of cannula site bleeding decreased from 22% to 12% (p = 0.04), and surgical site bleeding decreased from 38% to 25% (p = 0.02). Median extracorporeal membrane oxygenation circuit life increased from 3.6 to 4.3 days (p = 0.02). A trend toward increased patient survival was noted, but it did not reach statistical significance.

CONCLUSIONS

We demonstrate an association between an extracorporeal membrane oxygenation anticoagulation laboratory protocol using anti-factor Xa assays, thromboelastography, and antithrombin measurements and a decrease in blood product transfusion, a decrease in hemorrhagic complications, and an increase in circuit life. To our knowledge, this is the first study to demonstrate clinical benefit associated with the use of these laboratory values for patients on extracorporeal membrane oxygenation.

Perioperative neonatal and paediatric blood transfusion

Paediatric patients undergoing surgical procedures commonly require some volume of blood or blood component replacement in the perioperative period. Paediatric patients undergoing major surgery associated with substantial blood loss should be evaluated pre-operatively. Pre-operative correction of anaemia may be done considering the age, plasma volume status, clinical status and comorbidities. Maximum allowable blood loss (MABL) for surgery must be calculated, and appropriate quantity of blood and blood components should be arranged. Intraoperative monitoring of blood loss should be done, and volume of transfusion should be calculated in a protocol based manner considering the volemia and the trigger threshold for transfusion for the patient and the MABL. Early haemostasis should be achieved by judicious administration of red blood cells, blood components and pharmacological agents.

RBC transfusion in pediatric patients supported with extracorporeal membrane oxygenation: is there an impact on tissue oxygenation?

OBJECTIVE

To examine first the RBC transfusion practice in pediatric patients supported with extracorporeal membrane oxygenation and second the relationship between transfusion of RBCs and changes in mixed venous saturation (SvO2) and cerebral regional tissue oxygenation, as measured by near-infrared spectroscopy in patients supported with extracorporeal membrane oxygenation.

DESIGN

Retrospective observational study.

SETTING

Pediatric, cardiovascular, and neonatal ICUs of a tertiary care children's hospital.

PATIENTS

All pediatric patients supported with extracorporeal membrane oxygenation between January 1, 2010, and December 31, 2010.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

There were 45 patients supported with extracorporeal membrane oxygenation. The median (interquartile range) phlebotomy during extracorporeal membrane oxygenation was 75 mL/kg (33, 149 mL/kg). A total of 617 transfusions were administered (median, 9 per patient; range = 1-57). RBC volumes transfused during extracorporeal membrane oxygenation support were 254 mL/kg (136, 557) and 267 mL/kg (187, 393; p = 0.82) for cardiac and noncardiac patients, respectively. Subtracting the volume of RBCs used for extracorporeal membrane oxygenation circuit priming, median RBC transfusion volumes were 131 and 80 mL/kg for cardiac and noncardiac patients, respectively (p = 0.26). The cardiac surgical patients received the most RBCs (529 vs 74 mL/kg for nonsurgical cardiac patients). The median hematocrit maintained during extracorporeal membrane oxygenation support was 37%, with no difference between cardiac and noncardiac patients. Patients supported with extracorporeal membrane oxygenation were exposed to a median of 10.9 (range, 3-43) individual donor RBC units. Most transfusions resulted in no significant change in either SvO2 or cerebral near-infrared spectroscopy. Only 5% of transfusions administered (31/617) resulted in an increase in SvO2 of more than 5%, whereas an increase in cerebral near-infrared spectroscopy of more than 5 was only observed in 9% of transfusions (53/617). Most transfusions (73%) were administered at a time when the pretransfusion SvO2 was more than 70%.

CONCLUSIONS

Patients supported with extracorporeal membrane oxygenation were exposed to large RBC transfusion volumes for treatment of mild anemia resulting from blood loss, particularly phlebotomy. In the majority of events, RBC transfusion did not significantly alter global tissue oxygenation, as assessed by changes in SvO2 and cerebral near-infrared spectroscopy. Most transfusions were administered at a time at which the patient did not appear to be oxygen delivery dependent according to global measures of tissue oxygenation.

Red cell transfusion management for patients undergoing cardiac surgery for congenital heart disease

BACKGROUND

Congenital heart disease is the most commonly diagnosed neonatal congenital condition. Without surgery, only 30% to 40% of patients affected will survive to 10 years old. Mortality has fallen since the 1990s with 2006 to 2007 figures showing surgical survival at one year of 95%. Patients with congenital heart disease are potentially exposed to red cell transfusion at many points in the surgical pathway. There are a number of risks associated with red cell transfusion that may be translated into increased patient morbidity and mortality.

OBJECTIVES

To evaluate the effects of red cell transfusion on mortality and morbidity on patients with congenital heart disease at the time of cardiac surgery.

SEARCH METHODS

We searched 11 bibliographic databases and three ongoing trials databases including the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 5, 2013), MEDLINE (Ovid, 1950 to 11 June 2013), EMBASE (Ovid, 1980 to 11 June 2013), ClinicalTrials.gov, World Health Organization (WHO) ICTRP and the ISRCTN Register (to June 2013). We also searched references of all identified trials, relevant review articles and abstracts from between 2006 and 2010 of the most relevant conferences. We did not limit the searches by language of publication.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing red cell transfusion interventions in patients undergoing cardiac surgery for congenital heart disease. We included participants of any age (neonates, paediatrics and adults) and with any type of congenital heart disease (cyanotic or acyanotic). We excluded patients with congenital heart disease undergoing non-cardiac surgery. No co-morbidities were excluded.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. We contacted study authors for additional information.

MAIN RESULTS

We identified 11 trials (862 participants). All trials were in neonatal or paediatric populations. The trials covered only three areas of interest: restrictive versus liberal transfusion triggers (two trials), leukoreduction versus non-leukoreduction (two trials) and standard versus non-standard cardiopulmonary bypass (CPB) prime (seven trials). Owing to the clinical diversity in the participant groups (cyanotic (three trials), acyanotic (four trials) or mixed (four trials)) and the intervention groups, it was not appropriate to pool data in a meta-analysis. No study reported data for all the outcomes of interest to this review. Risk of bias was mixed across the included trials, with only attrition bias being low across all trials. Blinding of study personnel and participants was not always possible, depending on the intervention being used.Five trials (628 participants) reported the primary outcome: 30-day mortality. In three trials (a trial evaluating restrictive and liberal transfusion (125 participants), a trial of cell salvage during CPB (309 participants) and a trial of washed red blood cells during CPB (128 participants)), there was no clear difference in mortality at 30 days between the intervention arms. In two trials comparing standard and non-standard CPB prime, there were no deaths in either randomised group. Long-term mortality was similar between randomised groups in one trial each comparing restrictive and liberal transfusion or standard and non-standard CPB prime.Four trials explored a range of adverse effects following red cell transfusion. Kidney failure was the only adverse event that was significantly different: patients receiving cell salvaged red blood cells during CPB were less likely to have renal failure than patients not exposed to cell salvage (risk ratio (RR) 0.26, 95% confidence interval (CI) 0.09 to 0.79, 1 study, 309 participants). There was insufficient evidence to determine whether there was a difference between transfusion strategies for any other severe adverse events.The duration of mechanical ventilation was measured in seven trials (768 participants). Overall, there was no consistent difference in the duration of mechanical ventilation between the intervention and control arms.The duration of intensive care unit (ICU) stay was measured in six trials (459 participants). There was no clear difference in the duration of ICU stay between the intervention arms in the transfusion trigger and leukoreduction trials. In the standard versus non-standard CPB prime trials, one trial examining the impact of washing transfused bypass prime red blood cells showed no clear difference in duration of ICU stay between the intervention arms, while the trial assessing ultrafiltration of the priming blood showed a shorter duration of ICU stay in the ultrafiltration group.

AUTHORS' CONCLUSIONS

There are only a small number of small and heterogeneous trials so there is insufficient evidence to assess the impact of red cell transfusion on patients with congenital heart disease undergoing cardiac surgery accurately. It is possible that the presence or absence of cyanosis impacts on trial outcomes, which would necessitate different clinical management of two groups. Further adequately powered, specific, high-quality trials are warranted to assess this fully.

Changes in transfusion practice over time in the PICU

OBJECTIVES

Recent randomized clinical trials have shown the efficacy of a restrictive transfusion strategy in critically ill children. The impact of these trials on pediatric transfusion practice is unknown. Additionally, long-term trends in pediatric transfusion practice in the ICU have not been described. We assessed transfusion practice over time, including the effect of clinical trial publication.

DESIGN

Single-center, retrospective observational study.

SETTING

A 10-bed PICU in an urban academic medical center.

PATIENTS

Critically ill, nonbleeding children between the ages of 3 days and 14 years old, admitted to the University of Maryland Medical Center PICU between January 1, 1998, and December 31, 2009, excluding those with congenital heart disease, hemolytic anemia, and hemoglobinopathies.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

During the time period studied, 5,327 patients met inclusion criteria. Of these, 335 received at least one RBC transfusion while in the PICU. The overall proportion transfused declined from 10.5% in 1998 to 6.8% in 2009 (p = 0.007). Adjusted for acuity, the likelihood of transfusion decreased by calendar year of admission. In transfused patients, the pretransfusion hemoglobin level declined, from 10.5 g/dL to 9.3 g/dL, though these changes failed to meet statistical significance (p = 0.09). Neonatal age, respiratory failure, shock, multiple organ dysfunction syndrome, and acidosis were associated with an increased likelihood of transfusion in both univariate and multivariable models.

CONCLUSIONS

The overall proportion of patients transfused between 1998 and 2009 decreased significantly. The magnitude of the decrease varied over time, and no additional change in transfusion practice occurred after the publication of a major pediatric clinical trial in 2007. Greater illness acuity and younger patient age were associated with an increased likelihood of transfusion.

Transfusion in critically ill children: an ongoing dilemma

Transfusion of blood products is a cornerstone in managing many critically ill children. Major improvements in blood product safety have not diminished the need for caution in transfusion practice. In this review, we aim to discuss the interplay between benefits and potential adverse effects of transfusion in critically ill children by including 65 papers, which were evaluated based on previously agreed selection criteria. Current practice on transfusing critically ill children is mainly founded on the basis of adult studies, common practices with cut-off values, and expert opinions, rather than evidence-based medicine. Paediatric patients have explicit physiological challenges and requirements to be addressed. Critically ill children often suffer from anaemia, have substantial iatrogenic blood loss with subsequent transfusions, and are at a higher risk of complications, often due to human errors. Transfusion in children is associated with increased morbidity. A restrictive transfusion strategy is not associated with increased morbidity. Thus, transfusion in paediatrics should be considered a high-risk treatment and requires individual clinical assessment. Current level of evidence support the notion that in most stable cases, despite high severity of illness (cyanotic children and neonates excluded), a restrictive haemoglobin threshold of 70 g/l (4.3 mmol/l) is no more harmful than to transfuse at a liberal trigger, e.g. haemoglobin 95 g/l (5.9 mmol/l). Thus, balanced against potential benefits and often its necessity, a restrictive approach may be appropriate due to the associated risks of transfusion.

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

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

Current status of pharmacologic therapies in patient blood management

Patient blood management(1,2) incorporates patient-centered, evidence-based medical and surgical approaches to improve patient outcomes by relying on the patient's own (autologous) blood rather than allogeneic blood. Particular attention is paid to preemptive measures such as anemia management. The emphasis on the approaches being "patient-centered" is to distinguish them from previous approaches in transfusion medicine, which have been "product-centered" and focused on blood risks, costs, and inventory concerns rather than on patient outcomes. Patient blood management(3) structures its goals by avoiding blood transfusion(4) with effective use of alternatives to allogeneic blood transfusion.(5) These alternatives include autologous blood procurement, preoperative autologous blood donation, acute normovolemic hemodilution, and intra/postoperative red blood cell (RBC) salvage and reinfusion. Reviewed here are the available pharmacologic tools for anemia and blood management: erythropoiesis-stimulating agents (ESAs), iron therapy, hemostatic agents, and potentially, artificial oxygen carriers.

Red blood cell transfusion in non-bleeding critically ill patients with moderate anemia: is there a benefit?

PURPOSE

This study was undertaken to investigate the efficacy of red blood cell transfusion (RBCT) at reversing the deleterious effects of moderate anemia in critically ill, non-bleeding patients.

METHODS

This was a retrospective, pair-matched (ratio 1:1) cohort study. Non-bleeding critically ill patients with moderate anemia (nadir hemoglobin level between 70 and 95 g/l), admitted to the ICU over a 27-month period, were included. Anemic patients were included upon meeting five matching criteria of having the same nadir hemoglobin (±5 g/l), APACHE II score (±5), SOFA score (±2), admission diagnostic group, and age (±5 years). Outcome events occurring over the whole ICU stay and after RBCT were collected. After hospital discharge, all patients had a 2-year follow-up period.

RESULTS

Two hundred fourteen non-transfused anemic patients (NTAPs) were successfully matched with 214 transfused anemic patients (TAPs). In addition to the matching criteria, at baseline, both groups were homogenous with respect to multiple comorbidities. Compared with TAPs, NTAPs showed significantly lower rates of hospital mortality (21 vs.13 %, respectively; p < 0.05) and ICU re-admission (7.4 vs. 1.9 %, respectively; p < 0.05). Additionally, NTAPs had significantly lower rates of nosocomial infection (12.9 vs. 6.7 %, respectively; p < 0.05) and acute kidney injury (24.8 vs. 16.7 %, respectively; p < 0.05). Similar results were obtained in subgroup analysis where only more anemic patients (68 matched pairs) or patients with cardiovascular comorbidities (63 matched pairs) were considered.

CONCLUSIONS

RBCT does not improve the clinical outcome in non-bleeding critically ill patients with moderate anemia.

Hydroxyethyl starch 130/0.42/6:1 for perioperative plasma volume replacement in 1130 children: results of an European prospective multicenter observational postauthorization safety study (PASS)

INTRODUCTION

Third-generation hydroxyethyl starch (HES) is now approved also for the use in children, but safety studies including large numbers of pediatric patients are still missing. Therefore, we performed an European multicentric prospective observational postauthorization safety study (PASS) to evaluate the use of HES 130/0.42/6:1 in normal saline (ns-HES) or a balanced electrolyte solution (bal-HES) in children undergoing surgery.

METHODS

Children aged up to 12 years with ASA risk scores of I-III receiving ns-HES (Venofundin 6%; Braun) or bal-HES (Tetraspan 6%; Braun) were followed perioperatively. Demographic data, surgical procedures performed, anesthesia, hemodynamic and laboratory data, adverse events (AE), and adverse drug reactions (ADR) were documented using a standardized case report form.

RESULTS

Of 1130 children studied at 11 European pediatric centers from 2006 to 2009 (ns-HES, 629 children; bal-HES, 475 children; mean age, 3.6 ± 3.8 [range, day of birth-12 years]; and body weight, 15.4 ± 13 [0.9-90 kg]), 1104 were included for analysis. The mean infused HES volume was 10.6 ± 5.8 (0.83-50) ml·kg(-1). In the 399 (36.1%) cases with blood gas analysis before and after HES infusion, hemoglobin and strong ion difference decreased significantly in both groups, whereas bicarbonate and base excess (BE before infusion: ns-HES -1.8 ± 3.1, bal-HES -1.2 ± 3.3 mm; after infusion: ns-HES -2.5 ± 2.8; bal-HES -1.1 ± 3.2 mm, P < 0.05) decreased only with ns-HES but remained stable with bal-HES. Chloride concentrations increased in both groups and were significantly higher with ns-HES (Cl before infusion: ns-HES 105.5 ± 3.6, bal-HES 104.9 ± 2.9 mm; Cl after infusion: ns-HES 107.6 ± 3.4, bal-HES 106.3 ± 2.9 mm, P < 0.05). For the AE/ADR rates, dose-response but no age relationships could be demonstrated. No serious and no severe ADR directly related to HES (i.e. anaphylactoid reaction, clotting disorders, renal failure) were observed.

CONCLUSION

Moderate doses of HES 130/0.42/6:1 for perioperative plasma volume replacement seem to be safe even in neonates and small infants. The probability of serious ADR is lower than 0.3%. Changes in acid-base balance may be decreased when HES is used in an acetate-containing balanced electrolyte solution instead of normal saline. Caution should be exercised in patients with renal function disturbances and those with an increased bleeding risk.

Evidence-Based Principles in Pathology: Existing Problem Areas and the Development of “Quality” Practice Patterns

Context.—Contrary to the intuitive impressions of many pathologists, several areas exist in laboratory medicine where evidence-based medicine (EBM) principles are not applied. These include aspects of both anatomic and clinical pathology. Some non-EBM practices are perpetuated by clinical “consumers” of laboratory services because of inadequate education, habit, or overreliance on empirical factors. Other faulty procedures are driven by pathologists themselves.

Objectives.—To consider (1) several selected problem areas representing non-EBM practices in laboratory medicine; such examples include ideas and techniques that concern metastatic malignancies, “targeted” oncologic therapy, general laboratory testing and data utilization, evaluation of selected coagulation defects, administration of blood products, and analysis of hepatic iron-overload syndromes; and (2) EBM principles as methods for remediation of deficiencies in hospital pathology, and implements for the construction of “quality” practices in our specialty.

Data Sources.—Current English literature relating to evidence-based principles in pathology and laboratory medicine, as well as the authors' experience.

Conclusions.—Evidence-based medicine holds the promise of optimizing laboratory services to produce “quality” practices in pathology. It will also be a key to restraining the overall cost of health care.