Can we safely restrict transfusion in trauma patients?

Transfusion Decision Making in Pediatric Critical Illness

Transfusion decision making (TDM) in the critically ill requires consideration of: (1) anemia tolerance, which is linked to active pathology and to physiologic reserve, (2) differences in donor RBC physiology from that of native RBCs, and (3) relative risk from anemia-attributable oxygen delivery failure vs hazards of transfusion, itself. Current approaches to TDM (e.g. hemoglobin thresholds) do not: (1) differentiate between patients with similar anemia, but dissimilar pathology/physiology, and (2) guide transfusion timing and amount to efficacy-based goals (other than resolution of hemoglobin thresholds). Here, we explore approaches to TDM that address the above gaps.

Specific Etiologies Associated With the Multiple Organ Dysfunction Syndrome in Children: Part 2

OBJECTIVE

To describe a number of conditions and therapies associated with multiple organ dysfunction syndrome presented as part of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Multiple Organ Dysfunction Workshop (March 26-27, 2015). In addition, the relationship between burn injuries and multiple organ dysfunction syndrome is also included although it was not discussed at the workshop.

DATA SOURCES

Literature review, research data, and expert opinion.

STUDY SELECTION

Not applicable.

DATA EXTRACTION

Moderated by an expert from the field, issues relevant to the association of multiple organ dysfunction syndrome with a variety of conditions and therapies were presented, discussed, and debated with a focus on identifying knowledge gaps and the research priorities.

DATA SYNTHESIS

Summary of presentations and discussion supported and supplemented by relevant literature.

CONCLUSIONS

Sepsis and trauma are the two conditions most commonly associated with multiple organ dysfunction syndrome both in children and adults. However, many other pathophysiologic processes may result in multiple organ dysfunction syndrome. In this article, we discuss conditions such as liver failure and pancreatitis, pathophysiologic processes such as ischemia and hypoxia, and injuries such as trauma and burns. Additionally, therapeutic interventions such as medications, blood transfusions, transplantation may also precipitate and contribute to multiple organ dysfunction syndrome. The purpose of this article is to describe the association of multiple organ dysfunction syndrome with a variety of conditions and therapies in an attempt to identify similarities, differences, and opportunities for therapeutic intervention.

Transfusion of older stored blood and risk of death: a meta-analysis

BACKGROUND

Blood for transfusion is stored for up to 42 days. Older blood develops lesions and accumulates potentially injurious substances. Some studies report increasing toxicity as blood ages. We assessed the safety of transfused older versus newer stored blood.

STUDY DESIGN AND METHODS

PubMed, Scopus, and Embase were searched using terms new and old and red blood cell and storage through May 6, 2011, for observational and randomized controlled studies comparing outcomes using transfused blood having longer and shorter storage times. Death was the outcome of interest.

RESULTS

Twenty-one studies were identified, predominantly in cardiac surgery (n=6) and trauma (n=6) patients, including 409,966 patients. A test for heterogeneity of these studies' results was not significant for mortality (I(2)=3.7%, p=0.41). Older blood was associated with a significantly increased risk of death (odds ratio, 1.16; 95% confidence interval [CI], 1.07-1.24). Using available mortality data, 97 (95% CI, 63-199) patients need to be treated with only new blood to save one life. Subgroup analysis of these trials indicated that the increased risk was not restricted to a particular type of patient, size of trial, or amount of blood transfused.

CONCLUSION

Based on available data, use of older stored blood is associated with a significantly increased risk of death.

Red blood cell transfusion following burn

A severe burn will significantly alter haematologic parameters, and manifest as anaemia, which is commonly found in patients with greater than 10% total body surface area (TBSA) involvement. Maintaining haemoglobin and haematocrit levels with blood transfusion has been the gold standard for the treatment of anaemia for many years. While there is no consensus on when to transfuse, an increasing number of authors have expressed that less blood products should be transfused. Current transfusion protocols use a specific level of haemoglobin or haematocrit, which dictates when to transfuse packed red blood cells (PRBCs). This level is known as the trigger. There is no one 'common trigger' as values range from 6 g dl(-1) to 8 g dl(-1) of haemoglobin. The aim of this study was to analyse the current status of red blood cell (RBC) transfusions in the treatment of burn patients, and address new information regarding burn and blood transfusion management. Analysis of existing transfusion literature confirms that individual burn centres transfuse at a lower trigger than in previous years. The quest for a universal transfusion trigger should be abandoned. All RBC transfusions should be tailored to the patient's blood volume status, acuity of blood loss and ongoing perfusion requirements. We also focus on the prevention of unnecessary transfusion as well as techniques to minimise blood loss, optimise red cell production and determine when transfusion is appropriate.

Association between length of storage of transfused red blood cells and multiple organ dysfunction syndrome in pediatric intensive care patients

BACKGROUND

The objective was to determine if there is an association between red blood cell (RBC) storage time and development of new or progressive multiple organ dysfunction syndrome (MODS) in critically ill children.

STUDY DESIGN AND METHODS

This was an analytic cohort analysis of patients enrolled in a randomized controlled trial, TRIPICU (Transfusion Requirements in Pediatric Intensive Care Units; ISRCTN37246456), in which stable critically ill children were randomly assigned to a restrictive or liberal strategy. Transfused patients were analyzed using three different sliding time cutoffs (7, 14, and 21 days). Storage time for multiply transfused patients was defined according to the oldest unit transfused.

RESULTS

A total of 455 patients were retained (liberal, 310; restrictive, 145). Multivariate logistic regression was performed to determine independent associations. In the restrictive group, a maximum RBC storage time of more than 21 days was independently associated with new or progressive MODS (adjusted odds ratio [OR], 3.29; 95% confidence interval [CI], 1.21-9.04). The same association was found in the liberal group for a storage time of more than 14 days (adjusted OR, 2.50; 95% CI, 1.12-5.58). When the two groups were combined in a meta-analysis, a storage time of more than 14 days was independently associated with increased MODS (adjusted OR, 2.23; 95% CI, 1.20-4.15) and more than 21 days was associated with increased Pediatric Logistic Organ Dysfunction (PELOD) scores (adjusted mean difference, 4.26; 95% CI, 1.99-6.53) and higher mortality (9.2% vs. 3.8%).

CONCLUSION

Stable critically ill children who receive RBC units with storage times longer than 2 to 3 weeks may be at greater risk of developing new or progressive MODS.

Increasing hematocrit above 28% during early resuscitative phase is not associated with decreased mortality following severe traumatic brain injury

BACKGROUND

To prevent iatrogenic damage, transfusions of red blood cells should be avoided. For this, specific and reliable transfusion triggers must be defined. To date, the optimal hematocrit during the initial operating room (OR) phase is still unclear in patients with severe traumatic brain injury (TBI). We hypothesized that hematocrit values exceeding 28%, the local hematocrit target reached by the end of the initial OR phase, resulted in more complications, increased mortality, and impaired recovery compared to patients in whom hematocrit levels did not exceed 28%.

METHODS

Impact of hematocrit (independent variable) reached by the end of the OR phase on mortality and morbidity determined by the extended Glasgow outcome scale (eGOS; dependent variables) was investigated retrospectively in 139 TBI patients. In addition, multiple logistic regression analysis was performed to identify additional important variables.

FINDINGS

Following severe TBI, mortality and morbidity were neither aggravated by hematocrit above 28% reached by the end of the OR phase nor worsened by the required transfusions. Upon multiple logistic regression analysis, eGOS was significantly influenced by the highest intracranial pressure and the lowest cerebral perfusion pressure values during the initial OR phase.

CONCLUSIONS

Based on this retrospective observational analysis, increasing hematocrit above 28% during the initial OR phase following severe TBI was not associated with improved or worsened outcome. This questions the need for aggressive transfusion management. Prospective analysis is required to determine the lowest acceptable hematocrit value during the OR phase which neither increases mortality nor impairs recovery. For this, a larger caseload and early monitoring of cerebral metabolism and oxygenation are indispensable.

Resuscitation and transfusion principles for traumatic hemorrhagic shock

The transfusion approach to massive hemorrhage has continually evolved since it began in the early 1900s. It started with fresh whole blood and currently consists of virtually exclusive use of component and crystalloid therapy. Recent US military experience has reinvigorated the debate on what the most optimal transfusion strategy is for patients with traumatic hemorrhagic shock. In this review we discuss recently described mechanisms that contribute to traumatic coagulopathy, which include increased anti-coagulation factors and hyperfibrinolysis. We also describe the concept of damage control resuscitation (DCR), an early and aggressive prevention and treatment of hemorrhagic shock for patients with severe life-threatening traumatic injuries. The central tenants of DCR include hypotensive resuscitation, rapid surgical control, prevention and treatment of acidosis, hypothermia, and hypocalcemia, avoidance of hemodilution, and hemostatic resuscitation with transfusion of red blood cells, plasma, and platelets in a 1:1:1 unit ratio and the appropriate use of coagulation factors such as rFVIIa and fibrinogen-containing products (fibrinogen concentrates, cryoprecipitate). Fresh whole blood is also part of DCR in locations where it is available. Additional concepts to DCR since its original description that can be considered are the preferential use of "fresh" RBCs, and when available thromboelastography to direct blood product and hemostatic adjunct (anti-fibrinolytics and coagulation factor) administration. Lastly we discuss the importance of an established massive transfusion protocol to rapidly employ DCR and hemostatic resuscitation principles. While the majority of recent trauma transfusion papers are supportive of these general concepts, there is no Level 1 or 2 data available. Taken together, the preponderance of data suggests that these concepts may significantly decrease mortality in massively transfused trauma patients.

Transfusion of blood products in trauma: an update

BACKGROUND

Blood transfusion in the management of severely injured patients can be lifesaving. These patients are susceptible to developing early coagulopathy, thus perpetuating bleeding.

OBJECTIVES

This article presents recent advances in both the civilian and military clinical arena to improve the treatment of trauma patients with severe hemorrhage, the use of agents to support coagulation, perspectives on restrictive transfusion strategies, and transfusion-related risks.

DISCUSSION

Massive blood transfusion is an adjunct to surgical care. The volume of blood products transfused and the ratio of blood components have been associated with increased morbidity and mortality rates. The adverse clinical effects of transfusion and the limited supply of blood products have resulted in modern resuscitation protocols to limit the volume of blood transfused.

CONCLUSION

A restrictive blood transfusion strategy and the use of hemostatic agents may decrease morbidity and mortality in trauma patients, but insufficient data are available for their use in trauma patients. Massive transfusion should reflect an equal ratio of packed red cells and plasma to limit coagulopathy. Prospective randomized trials are needed to standardize an effective protocol.

The role of erythropoietin in the acute phase of trauma management: evidence today

Trauma patients often present in a state of haemorrhagic shock. Blood products remain the gold standard of resuscitation, but allogeneic blood transfusions (ABTs) are associated with several risks. The stimulating effect of recombinant-erythropoietin (EPO-A) on erythropoiesis has raised interest in its administration as an alternative. The existing evidence on the early use of EPO-A in the acute phase of trauma patients management consists of only 14 publications. The level of evidence of these studies and the number of treated patients was not found to be adequate to support its generalised use, despite their favourable results. Its safety profile, the preliminary proofs of its efficacy, and the additional cyto-protective properties of EPO-A strongly encourage further controlled studies assessing its use in the acute setting of initial trauma management.

Risks associated with fresh whole blood and red blood cell transfusions in a combat support hospital

OBJECTIVE

Fresh whole blood (FWB) and red blood cells (RBCs) are transfused to injured casualties in combat support hospitals. We evaluated the risks of FWB and RBCs transfused to combat-related casualties.

DESIGN

Retrospective chart review.

SETTING

Deployed U.S. Army combat support hospitals.

SUBJECTS

Donors of FWB and recipients of FWB and RBCs.

MEASUREMENTS AND RESULTS

The storage age of RBCs at transfusion was measured as an indicator of overall risk associated with the storage lesion of RBCs between January 2004 and December 2004 at one combat support hospital. Between April 2004 and December 2004, FWB was prescreened only at one combat support hospital for human immunodeficiency virus, hepatitis C virus, and hepatitis B surface antigen before transfusion. To estimate the general incidence of infectious agent contamination in FWB units, samples collected between May 2003 and February 2006 were tested retrospectively for human immunodeficiency virus, hepatitis B surface antigen, hepatitis C virus, and human lymphotropic virus. Results were compared between FWB samples prescreened and not prescreened for infectious agents before transfusion. At one combat support hospital in 2004, 87 patients were transfused 545 units of FWB and 685 patients were transfused 5,294 units of RBCs with a mean age at transfusion of 33 days (+/- 6 days). Retrospective testing of 2,831 samples from FWB donor units transfused in Iraq and Afghanistan between May 2003 and February 2006 indicated that three of 2,831 (0.11%) were positive for hepatitis C virus recombinant immunoblot assay, two of 2,831 (0.07%) were positive for human lymphotropic virus enzyme immunoassay, and none of 2,831 were positive for both human immunodeficiency virus 1/2 and hepatitis B surface antigen by Western blot and neutralization methods, respectively. The differences in the incidence of hepatitis C virus contamination of FWB donor units between those prescreened for hepatitis C virus (zero of 406; 0%) and not prescreened (three of 2,425; 0.12%) were not significant (p = .48).

CONCLUSIONS

The risk of infectious disease transmission with FWB transfusion can be minimized by rapid screening tests before transfusion. Because of the potential adverse outcomes of transfusing RBCs of increased storage age to combat-related trauma patients, the risks and benefits of FWB transfusions must be balanced with those of transfusing old RBCs in patients with life-threatening traumatic injuries.

The ratio of blood products transfused affects mortality in patients receiving massive transfusions at a combat support hospital

BACKGROUND

Patients with severe traumatic injuries often present with coagulopathy and require massive transfusion. The risk of death from hemorrhagic shock increases in this population. To treat the coagulopathy of trauma, some have suggested early, aggressive correction using a 1:1 ratio of plasma to red blood cell (RBC) units.

METHODS

We performed a retrospective chart review of 246 patients at a US Army combat support hospital, each of who received a massive transfusion (>/=10 units of RBCs in 24 hours). Three groups of patients were constructed according to the plasma to RBC ratio transfused during massive transfusion. Mortality rates and the cause of death were compared among groups.

RESULTS

For the low ratio group the plasma to RBC median ratio was 1:8 (interquartile range, 0:12-1:5), for the medium ratio group, 1:2.5 (interquartile range, 1:3.0-1:2.3), and for the high ratio group, 1:1.4 (interquartile range, 1:1.7-1:1.2) (p < 0.001). Median Injury Severity Score (ISS) was 18 for all groups (interquartile range, 14-25). For low, medium, and high plasma to RBC ratios, overall mortality rates were 65%, 34%, and 19%, (p < 0.001); and hemorrhage mortality rates were 92.5%, 78%, and 37%, respectively, (p < 0.001). Upon logistic regression, plasma to RBC ratio was independently associated with survival (odds ratio 8.6, 95% confidence interval 2.1-35.2).

CONCLUSIONS

In patients with combat-related trauma requiring massive transfusion, a high 1:1.4 plasma to RBC ratio is independently associated with improved survival to hospital discharge, primarily by decreasing death from hemorrhage. For practical purposes, massive transfusion protocols should utilize a 1:1 ratio of plasma to RBCs for all patients who are hypocoagulable with traumatic injuries.

[Incidence and mortality of massive transfusion in a university hospital: study of the period 2001-2005]

BACKGROUND AND OBJECTIVE

There are few epidemiological studies on massive transfusion (MT), although they may be important to evaluate possible strategies to reduce the number of transfused units, as well as transfusion side-effects. We, therefore, retrospectively assessed the incidence of MT at our institution (a 700-bed university hospital) during a 5-year period.

PATIENTS AND METHOD

Local blood bank records were searched for MT episodes occurred from January 2001 to December 2005. MT was defined as the transfusion of 8 or more packed red cell (PRC) units within 24 h. Patient's clinical data were exclusively gathered from the blood requesting form.

RESULTS

Overall, 304 episodes of MT were identified in 288 patients (one episode per week), who received 4,845 PCR units (3,515 units within the first 24 h), because of ruptured aortic aneurism (n = 62), poly-trauma (n = 57), upper digestive bleeding (n = 51), cardiac surgery (n = 41), elective surgery (n = 36), emergency surgery (n = 30), and oncology surgery (n = 27). Mortality rate was 48%, and multivariate analysis identified age (odds ratio [OR] =1.023; 95% confidence interval [CI]. 1.006-1.040) and number of PRC transfused within the first 24 h (OR = 1.094; 95% CI, 1.0032-1.160) as weak but significant independent predictors of mortality, whereas poly-trauma diagnosis was a protective factor (OR = 0.325; 95% CI, 0.112 - 0,940).

CONCLUSIONS

Overall, the mortality rate among patients receiving MT was very high, and was influenced by the number of transfused units, patient's age, and admitting diagnose. As the majority of the MT episodes occurred within the surgical or polytrauma context, possible strategies to reduce the volume of MT are discussed.