[Influence of massive blood transfusion and traumatic brain injury on TIMP‑1 and MMP‑9 serum levels in polytraumatized patients]

BACKGROUND

The morbidity and mortality of polytrauma patients are substantially influenced by the extent of the posttraumatic inflammatory reaction. Studies have shown that TIMP‑1 and MMP‑9 play a major role in posttraumatic immune disorder in genome-wide mRNA microarray analyses. Furthermore, both showed differential gene expression profiles depending on the clinical parameters massive blood transfusion and traumatic brain injury.

OBJECTIVE

The aim of this study was to evaluate TIMP‑1 and MMP‑9 serum concentrations in polytraumatized patients depending on the clinical parameters massive blood transfusion and traumatic brain injury in the early posttraumatic phase.

MATERIAL AND METHODS

Polytrauma patients (≥18 years) with an "Injury Severity Score" (ISS) ≥ 16 points were enrolled in this prospective study. Serum levels of TIMP‑1 and MMP‑9 were quantified (at 0 h, 6 h, 12 h, 24 h, 48 h and 72 h) using an enzyme-linked immunosorbent assay (ELISA). Groups were divided according to the clinical parameter massive blood transfusion (≥10 red blood cell units [RBC units] in the first 24-hour posttrauma) and traumatic brain injury (CCT postive [cranial computed tomography]).

RESULTS

Following massive blood transfusion (n = 21; 50 ± 15.7 years; ISS 39 ± 12.8 points) patients showed overall significantly increased TIMP‑1 levels (p = 0.003) and significantly higher TIMP‑1 values after 12-72 h. Traumatic brain injury patients (n = 28; 44 ± 19 years; ISS 42 ± 10 points) showed significantly higher MMP‑9 levels (p = 0.049) in the posttraumatic period.

CONCLUSION

Polytraumatized patients who received massive blood transfusions following major trauma showed significantly higher TIMP‑1 levels than patients who did not receive massive transfusions. This seems to be an expression of a massively excessive inflammatory reaction and therefore represents a substantial factor in the pathogenesis of severe posttraumatic immune dysfunction in this collective. Furthermore, the significant increase in MMP‑9 with accompanying traumatic brain injury reflects the pivotal role of matrix metalloproteinases in the pathophysiology of traumatic brain injury.

Neonatal Extracorporeal Membrane Oxygenation: Update on Management Strategies and Long-Term Outcomes

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) can be deployed to support patients with severe cardiorespiratory failure unresponsive to conventional medical interventions. Neonatal trials have demonstrated that ECMO is an effective treatment of severe respiratory failure, with acceptable cognitive and functional outcomes. Technological advances in ECMO have resulted in improved safety and accessibility, contributing to decreased morbidity and improved survival of increasingly complex patients requiring ECMO support.

PURPOSE

This review aims to describe the innovations in ECMO technology and management in the neonatal population in the last decade. The long-term outcomes of neonatal patients requiring ECMO support will be discussed.

SEARCH STRATEGY

Relevant clinical trials from MEDLINE and the Cochrane Library were identified. The following key words were used: ECMO, infant, neonate, and outcomes.

FINDINGS

Challenges still remain in supporting the premature and/or low-birth-weight infant with severe respiratory failure, as well as infants with congenital diaphragmatic hernia. Neonatal ECMO survivors can present with neurodevelopmental and respiratory problems, which become more prominent with time.

IMPLICATIONS FOR PRACTICE

While newer technologies have led to fewer neonates with respiratory failure progressing to ECMO, it remains an important tool to in those who have failed conventional therapies. Given the presence of neurodevelopmental problems in neonatal ECMO survivors, multidisciplinary follow-up targeting motor performance, exercise capacity, behavior, and subtle learning deficits is warranted.

IMPLICATIONS FOR RESEARCH

With the overall decreasing use of neonatal ECMO, ECMO centers must find ways to maintain their expertise in the light of lower patient volumes amidst complex patient physiology.

Risks associated with red blood cell transfusion in the trauma population, a meta-analysis

INTRODUCTION

A previous meta-analysis has found an association between red blood cell (RBC) transfusions and mortality in critically ill patients, but no review has focused on the trauma population only.

OBJECTIVES

To determine the association between RBC transfusion and mortality in the trauma population, with secondary outcomes of multiorgan failure (MOF) and acute respiratory distress syndrome (ARDS) or acute lung injury (ALI).

DATA SOURCES

EMBASE (1947-2012) and MEDLINE (1946-2012).

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials and observational studies were to be included if they assessed the association between RBC transfusion and either the primary (mortality) or secondary outcomes (MOF, ARDS/ALI).

PARTICIPANTS

Trauma patients.

EXPOSURE

Red blood cell transfusion.

METHODS

A literature search was completed and reviewed in duplicate to identify eligible studies. Studies were included in the pooled analyses if an attempt was made to determine the association between RBC and the outcomes, after adjusting for important confounders. A random effects model was used for and heterogeneity was quantified using the I(2) statistic. Study quality was assessed using the Newcastle-Ottawa Scale.

RESULTS

40 observational studies were included in the qualitative review. Including studies which adjusted for important confounders found the odds of mortality increased with each additional unit of RBC transfused (9 Studies, OR 1.07, 95%CI 1.04-1.10, I(2) 82.9%). The odds of MOF (3 studies, OR 1.08, 95%CI 1.02-1.14, I(2) 95.9%) and ARDS/ALI (2 studies, OR 1.06, 95%CI 1.03-1.10, I(2) 0%) also increased with each additional RBC unit transfused.

CONCLUSIONS

We have found an association between RBC transfusion and the primary and secondary outcomes, based on observational studies only. This represents the extent of the published literature. Further interventional studies are needed to clarify how limiting transfusion can affect mortality and other outcomes.

The impact of leukoreduced red blood cell transfusion on mortality of neonates undergoing extracorporeal membrane oxygenation

BACKGROUND

Blood products containing leukocytes have been associated with negative immunomodulatory and infectious effects. Transfusion-related acute lung injury is partially explained by leucocyte agglutination. The Food and Drug Administration has therefore recommended leukoreduction strategies for blood product transfusion. Our institution has been using leukocyte-reduced blood via filtration for neonates on Extracorporeal Membrane Oxygenation (ECMO). We hypothesized that the use of leukocyte-reduced blood would decrease mortality and morbidity of neonatal ECMO patients.

METHODS

Retrospective review of noncardiac ECMO in neonates from 1984-2011, stratified into year groups I and II (≤1996 and ≥1997). Demographics, duration and type of ECMO, complications, and outcome data were collected. Blood product use data was collected. Univariate, bivariate, and multivariate analyses determined predictors of risk-adjusted mortality by year group.

RESULTS

Patients (827) underwent ECMO with 65.3% (540) in group I. Overall median blood product use in mL/kg/d was 36.2 packed red blood cells (pRBC), 8.1 platelets, and 0 cyroprecipitate and/or fresh-frozen plasma. Overall mortality was 16.4%. Median pRBC used or transfused was 42.1 mL/kg/d in group I versus 19.1 mL/kg/d group II (P <0.001). On bivariate analysis, there was no difference in crude mortality between the 2 year groups (17.2% versus 16.0%, P = 0.66). However, on multivariate analysis adjusting for demographics, diagnosis, complications, and blood product use other than pRBCs, each additional transfusion of 10 mL/kg/d of pRBC was associated with a 33% increase in mortality in group I (P <0.05). Group II also showed an increase in mortality with each additional transfusion (21%) but this was not statistically significant (P = 0.07). Days on ECMO were not associated with pRBC transfusion in group I but increased in group II (additional 3 d for each 10 mL/kg/d transfused). There was no difference in infectious complications between groups I and II.

CONCLUSIONS

Blood transfusion requirement has diminished in newborns undergoing ECMO at our institution. Transfusion of non leukocyte-reduced blood is associated with an increase in mortality whereas transfusion of leukocyte-reduced blood provided no benefit with a trend toward increased mortality. Further research is recommended to understand these trends.

Transfusion immunomodulation--the case for leukoreduced and (perhaps) washed transfusions

During the last three decades, a growing body of clinical, basic science and animal model data has demonstrated that blood transfusions have important effects on the immune system. These effects include: dysregulation of inflammation and innate immunity leading to susceptibility to microbial infection, down-regulation of cellular (T and NK cell) host defenses against tumors, and enhanced B cell function that leads to alloimmunization to blood group, histocompatibility and other transfused antigens. Furthermore, transfusions alter the balance between hemostasis and thrombosis through inflammation, nitric oxide scavenging, altered rheologic properties of the blood, immune complex formation and, no doubt, several mechanisms not yet elucidated. The net effects are rarely beneficial to patients, unless they are in imminent danger of death due to exsanguination or life threatening anemia. These findings have led to appeals for more conservative transfusion practice, buttressed by randomized trials showing that patients do not benefit from aggressive transfusion practices. At the risk of hyperbole, one might suggest that if the 18th and 19th centuries were characterized by physicians unwittingly harming patients through venesection and bleeding, the 20th century was characterized by physicians unwittingly harming patients through current transfusion practices. In addition to the movement to more parsimonious use of blood transfusions, an effort has been made to reduce the toxic effects of blood transfusions through modifications such as leukoreduction and saline washing. More recently, there is early evidence that reducing the storage period of red cells transfused might be a strategy for minimizing adverse outcomes such as infection, thrombosis, organ failure and mortality in critically ill patients particularly at risk for these hypothesized effects. The present review will focus on two approaches, leukoreduction and saline washing, as means to reduce adverse transfusion outcomes.

Transfusion-related acute lung injury: a preventable syndrome?

Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related morbidity and mortality. Recent insights into the pathophysiology of TRALI have led to various preventive strategies. Strategies in donor management range from antibody testing of sensitized donors to the deferral of female plasma donors altogether. However, knowledge on the efficacy of measures to reduce TRALI is limited. In addition, the various measures may lead to a substantial loss of donors, hampering steady blood supply. Thereby, consensus among countries and blood-collecting facilities regarding the optimal strategy to prevent TRALI is lacking. In this review, the advantages and disadvantages of various preventive measures to prevent TRALI are discussed, related to both patient factors as well as blood component-processing strategies, including transfusion policy, donor management and practices of preparation and storage conditions of blood components.

Anemia in critical illness: insights into etiology, consequences, and management

Anemia is common in the intensive care unit, and may be associated with adverse consequences. However, current options for correcting anemia are not without problems and presently lack convincing efficacy for improving survival in critically ill patients. In this article we review normal red blood cell physiology; etiologies of anemia in the intensive care unit; its association with adverse outcomes; and the risks, benefits, and efficacy of various management strategies, including blood transfusion, erythropoietin, blood substitutes, iron therapy, and minimization of diagnostic phlebotomy.

2011 update to the Society of Thoracic Surgeons and the Society of Cardiovascular Anesthesiologists blood conservation clinical practice guidelines

BACKGROUND

Practice guidelines reflect published literature. Because of the ever changing literature base, it is necessary to update and revise guideline recommendations from time to time. The Society of Thoracic Surgeons recommends review and possible update of previously published guidelines at least every three years. This summary is an update of the blood conservation guideline published in 2007.

METHODS

The search methods used in the current version differ compared to the previously published guideline. Literature searches were conducted using standardized MeSH terms from the National Library of Medicine PUBMED database list of search terms. The following terms comprised the standard baseline search terms for all topics and were connected with the logical 'OR' connector--Extracorporeal circulation (MeSH number E04.292), cardiovascular surgical procedures (MeSH number E04.100), and vascular diseases (MeSH number C14.907). Use of these broad search terms allowed specific topics to be added to the search with the logical 'AND' connector.

RESULTS

In this 2011 guideline update, areas of major revision include: 1) management of dual anti-platelet therapy before operation, 2) use of drugs that augment red blood cell volume or limit blood loss, 3) use of blood derivatives including fresh frozen plasma, Factor XIII, leukoreduced red blood cells, platelet plasmapheresis, recombinant Factor VII, antithrombin III, and Factor IX concentrates, 4) changes in management of blood salvage, 5) use of minimally invasive procedures to limit perioperative bleeding and blood transfusion, 6) recommendations for blood conservation related to extracorporeal membrane oxygenation and cardiopulmonary perfusion, 7) use of topical hemostatic agents, and 8) new insights into the value of team interventions in blood management.

CONCLUSIONS

Much has changed since the previously published 2007 STS blood management guidelines and this document contains new and revised recommendations.

An association between decreased cardiopulmonary complications (transfusion-related acute lung injury and transfusion-associated circulatory overload) and implementation of universal leukoreduction of blood transfusions

BACKGROUND

Cardiopulmonary adverse events after transfusion include transfusion-related acute lung injury (TRALI) and transfusion-associated circulatory overload (TACO), which are potentially lethal and incompletely understood.

STUDY DESIGN AND METHODS

To determine whether the incidence of TRALI and TACO was affected by leukoreduction we conducted a retrospective, before-and-after study of acute transfusion reactions for the 7years before and after introduction of universal leukoreduction in 2000, involving 778,559 blood components.

RESULTS

Substantial decreases occurred in the rates of TRALI (-83%; from 2.8 cases per 100,000 components before to 0.48 after universal leukoreduction; p=0.01), TACO (-49%; 7.4 to 3.8 cases per 100,000; p=0.03), and febrile reactions (-35%; 11.4 to 7.4 cases per 10,000; p<0.0001). The incidence of allergic reactions remained unchanged (7.0 per 100,000 before and after universal leukoreduction). These outcomes were primarily attributable to decreased TRALI and/or TACO associated with red blood cell (RBC) and platelet (PLT) transfusions (-64%) with notably smaller decreases associated with fresh-frozen plasma or cryoprecipitate transfusions (-29%). The incidence of TRALI and/or TACO after 28,120 washed RBC and 69,325 washed transfusions was zero.

CONCLUSION

These data suggest novel hypotheses for further testing in animal models, in prospective clinical trials, and via the new US hemovigilance system: 1) Is TACO or TRALI mitigated by leukoreduction? 2) Is the mechanism of TACO more complex than excessive blood volume? and 3) Does washing mitigate TRALI and TACO due to PLT and RBC transfusions?

Early massive transfusion in trauma patients: Canadian single-centre retrospective cohort study

PURPOSE

To determine associations between red blood cell (RBC) transfusion and early and late clinical outcomes in massively transfused adult trauma patients.

METHODS

A retrospective cohort study (1992-2001) including 260 patients receiving >or=10 RBC units <or=24 hr after admission to a university-affiliated trauma centre. We extracted demographic and clinical data and used multivariable regression to determine independent effects of RBC transfusion on clinical outcomes.

RESULTS

Patients had a high (mean [standard deviation]) injury severity score (ISS) (42.5 [15.1]), a high admission sequential organ failure assessment (SOFA) score (8.4 [3.8]), and a high hospital mortality (58.5%). They received 38 (25-64) (median [interquartile range]) blood components within 48 hr, including 19 (14-28) RBC units. For 143 patients surviving >or=48 hr, the maximum SOFA score was associated with RBC units transfused before 48 hr (linear regression beta coefficient 0.075, P < 0.0001), lower nadir hemoglobin before 48 hr (0.034, P = 0.03), age (0.032, P = 0.015), and admission SOFA (0.59, P < 0.0001). The RBC units transfused by 48 hr were not associated with either hospital mortality (n = 35) among patients surviving >or=48 hr (independent predictors, age [logistic regression odds ratio (OR) 1.06, 95% confidence interval 1.03-1.10], ISS [OR 1.07, 1.02-1.13], and maximum SOFA score [OR 1.56, 1.27-1.93]) or 48-hr mortality (n = 117) (independent predictors, admission SOFA [1.65, 1.45-1.88] and later year of hospital admission [OR 1.15, 1.02-1.29]).

CONCLUSIONS

Hospital mortality is high among massively transfused trauma patients. Among early survivors, 48-hr RBC transfusion volume is associated with increased organ dysfunction, but not hospital mortality. Also, it is not associated with 48-hr mortality. Future research should continue to explore methods to improve hemostasis and minimize the need for RBC transfusion.

Comparison of Hemoglobin-based oxygen carriers to stored human red blood cells

Since the inception of allogeneic blood transfusion, the search for an alternative to the use of stored packed red blood cells has been underway. Over the last 10 years, modified hemoglobin solutions in the form of hemoglobin-based oxygen carriers (HBOCs) have made significant strides toward becoming clinically available and useful. Although HBOCs are not yet ready for regular use in the clinical arena, this may change in the near future as HBOC products continue to improve and as the elucidation of the mechanisms of any adverse effects becomes clearer. In the mean time, we must further the development of alternative strategies for the "hemoglobin bridge" so desperately needed by many critically ill patients.

Plasma from stored packed red blood cells and MHC class I antibodies causes acute lung injury in a 2-event in vivo rat model

Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion death. We hypothesize that TRALI requires 2 events: (1) the clinical condition of the patient and (2) the infusion of antibodies against MHC class I antigens or the plasma from stored blood. A 2-event rat model was developed with saline (NS) or endotoxin (LPS) as the first event and the infusion of plasma from packed red blood cells (PRBCs) or antibodies (OX18 and OX27) against MHC class I antigens as the second event. ALI was determined by Evans blue dye leak from the plasma to the bronchoalveolar lavage fluid (BALF), protein and CINC-1 concentrations in the BALF, and the lung histology. NS-treated rats did not evidence ALI with any second events, and LPS did not cause ALI. LPS-treated animals demonstrated ALI in response to plasma from stored PRBCs, both prestorage leukoreduced and unmodified, and to OX18 and OX27, all in a concentration-dependent fashion. ALI was neutrophil (PMN) dependent, and OX18/OX27 localized to the PMN surface in vivo and primed the oxidase of rat PMNs. We conclude that TRALI is the result of 2 events with the second events consisting of the plasma from stored blood and antibodies that prime PMNs.