Transfusions result in pulmonary morbidity and death after a moderate degree of injury

Burns in South Asia: Outcomes from South Asian Burn Registry (SABR)

BACKGROUND

South Asian region contributes 59 % to the global mortality due to burns. However, we find a paucity of literature on the outcomes of burns from low- and middle-income countries (LMICs). South Asian Burn Registry (SABR) is a facility-based burns registry that collected data on in-patient burn care. This study assesses factors associated with mortality, length of hospital stay at the burns center, and functional status of burn patients.

METHODS

Prospective data was collected from two specialized public sector burn centers between September 2014 - January 2015 from Bangladesh and Pakistan. Multivariable logistic, linear, and ordinal logistic regression was conducted to assess factors associated with inpatient-mortality, length of hospital stay, and functional status at discharge, respectively.

RESULTS

Data on 883 patients was analyzed. Increased association with mortality was observed with administration of blood product (OR:3, 95 % CI:1.18-7.58) and nutritional support (OR:4.32, 95 % CI:1.55-12.02). Conversely, antibiotic regimens greater than 8 days was associated with decreased mortality (OR:0.1, 95 % CI:0.03-0.41). Associated increase in length of hospital stay was observed in patients with trauma associated with their burn injury, history of seizures (CE:47.93, 95 % CI 12.05-83.80), blood product (CE:22.09, 95 % CI:0.83-43.35) and oxygen administration (CE:23.7, 95 % CI:7.34-40.06). Patients who developed sepsis (OR:6.89, 95 % CI:1.92-24.73) and received blood products during hospitalization (OR:2.55, 95 % CI:1.38- 4.73) were more likely to have poor functional status at discharge.

CONCLUSION

This study identified multiple factors associated with worse clinical outcomes for burn patients in South Asia. Understanding these parameters can guide targeted efforts to improve the process and quality of burn care in LMICs.

Predictors of long-term survival in 5,680 patients admitted to a UK major trauma centre with thoracic injuries

INTRODUCTION

The long-term outcomes of chest trauma are largely unknown. We sought to determine the predictors of in-hospital and long-term survival in patients admitted to a major trauma centre (MTC) with chest injuries and to evaluate spatial patterns of injury in our network area.

METHODS

Retrospective analysis of data collected on the National Trauma Audit Research Network (TARN) database using multivariate analysis and Cox regression analysis. Spatial analysis was performed using ArcGis 10.7.1.

RESULTS

Some 5,680 patients were admitted with chest trauma between December 1999 and December 2019. Median patient age was 45 years and the median Injury Severity Score (ISS) was 20. The proportion of patients who had an operation was 39.8%. Age, blood transfusion, head injury, shock, emergency thoracotomy and heart disease were predictors of hospital mortality (p < 0.05). However, having an operation on concomitant injuries was protective. ISS and Glasgow Coma Score were discriminators of in-hospital mortality (C-indices 0.76 and 0.80, respectively). The 10-year survival values for patients who survived to discharge from hospital and who were aged <40, 50, 60, 70, 80 and >80 years were 99%, 93%, 95%, 87%, 75% and 43%, respectively. Preadmission lung disease and alcohol/drug misuse were poor predictors of long-term survival (p < 0.05). Hotspot analysis revealed the areas with the highest incidents were all close to the MTC.

CONCLUSIONS

The MTC is geographically central to areas with high numbers of trauma incidents. Although emergency thoracotomy was a predictor of poor in-hospital outcomes, having surgery for concomitant injuries improved outcomes. Patients surviving to discharge have good long-term survivals.

Prolonged mechanical ventilation after lung transplantation: risks factors and consequences on recipient outcome

Background

Risk factors and the incidence of prolonged mechanical ventilation (PMV) after lung transplantation (LT) have been poorly described. The study assessed predictive factors of PMV after LT.

Methods

This observational, retrospective, monocentric study included all patients who received LT in Bichat Claude Bernard Hospital between January 2016 and December 2020. PMV was defined as a duration of MV > 14 days. Independent risk factors for PMV were studied using multivariate analysis. One-year survival depending on PMV was studied using Kaplan Meier and log-rank tests. A p value <0.05 was defined as significant.

Results

224 LT recipients were analysed. 64 (28%) of them received PMV for a median duration of 34 [26-52] days versus 2 [1-3] days without PMV. Independent risk factors for PMV were higher body mass index (BMI) (p = 0.031), diabetes mellitus of the recipient (p = 0.039), ECMO support during surgery (p = 0.029) and intraoperative transfusion >5 red blood cell units (p < 0.001). Increased mortality rates were observed at one-year in recipients who received PMV (44% versus 15%, p < 0.001).

Conclusion

PMV was associated with increased morbidity and mortality one-year after LT. Preoperative risk factors (BMI and diabetes mellitus) must be considered when selecting and conditioning the recipients.

Outcomes in Pediatric Trauma Patients Who Receive Blood Transfusion

INTRODUCTION

Increased blood volumes, due to massive transfusion (MT), are known to be associated with both infectious and noninfectious adverse outcomes. The aim of this study was to assess the association between MT and outcomes in pediatric trauma patients, and, secondarily, determine if these outcomes are differential by age once MT is reached.

METHODS

Pediatric patients (ages 1-18 y old) in the ACS pediatric Trauma Quality Improvement Program (TQIP) database (2015-2018) who received blood were included. Patients were stratified by MT status, which was defined as blood product volume of 40 mL/kg within 24 h of admission (MT+) and compared to children who received blood products but did not meet the MT threshold (MT-). Defined MT + patients were matched 1:1 to MT-patients via propensity score matching of characteristics before comparisons. Adjusted logistic regression was performed on univariably significant outcomes of interest.

RESULTS

There were 2318 patients in the analytic cohort. Patients who received MT had higher rates of deep venous thrombosis (DVT) (2.5% versus 1.0%, P < 0.001), acute kidney injury (AKI) (1.5% versus 0.0%, P = 0.022), CLABSI (4.0% versus 2.0% P = 0.008), and severe sepsis (2.3% versus. 1.1%, P = 0.02). On logistic regression MT was an independent risk factor for these outcomes. There was no differential effect of MT on these outcomes based on age.

CONCLUSIONS

Outcomes associated with blood transfusion in pediatric trauma patients are low overall, but rates of DVT, AKI, CLABSI, and sepsis are higher in those who receive MT+ with no differences based on age.

Intelligent prediction of RBC demand in trauma patients using decision tree methods

BACKGROUND

The vital signs of trauma patients are complex and changeable, and the prediction of blood transfusion demand mainly depends on doctors' experience and trauma scoring system; therefore, it cannot be accurately predicted. In this study, a machine learning decision tree algorithm [classification and regression tree (CRT) and eXtreme gradient boosting (XGBoost)] was proposed for the demand prediction of traumatic blood transfusion to provide technical support for doctors.

METHODS

A total of 1371 trauma patients who were diverted to the Emergency Department of the First Medical Center of Chinese PLA General Hospital from January 2014 to January 2018 were collected from an emergency trauma database. The vital signs, laboratory examination parameters and blood transfusion volume were used as variables, and the non-invasive parameters and all (non-invasive + invasive) parameters were used to construct an intelligent prediction model for red blood cell (RBC) demand by logistic regression (LR), CRT and XGBoost. The prediction accuracy of the model was compared with the area under the curve (AUC).

RESULTS

For non-invasive parameters, the LR method was the best, with an AUC of 0.72 [95% confidence interval (CI) 0.657-0.775], which was higher than the CRT (AUC 0.69, 95% CI 0.633-0.751) and the XGBoost (AUC 0.71, 95% CI 0.654-0.756, P < 0.05). The trauma location and shock index are important prediction parameters. For all the prediction parameters, XGBoost was the best, with an AUC of 0.94 (95% CI 0.893-0.981), which was higher than the LR (AUC 0.80, 95% CI 0.744-0.850) and the CRT (AUC 0.82, 95% CI 0.779-0.853, P < 0.05). Haematocrit (Hct) is an important prediction parameter.

CONCLUSIONS

The classification performance of the intelligent prediction model of red blood cell transfusion in trauma patients constructed by the decision tree algorithm is not inferior to that of the traditional LR method. It can be used as a technical support to assist doctors to make rapid and accurate blood transfusion decisions in emergency rescue environment, so as to improve the success rate of patient treatment.

Experience of outreach in a resource-constrained environment: 10 years of outcomes in burn care

OBJECTIVE

The objective of this work was to describe an efficient and sustainable outreach model in a resource-constrained environment, with a multifaceted approach focusing on national policy change, telemedicine, injury prevention, education and treatment of burns.

SUMMARY BACKGROUND DATA

Burn injury constitutes a significant portion of morbidity and mortality worldwide, particularly in children, and in low- and middle-income countries.

METHODS

We reviewed the impact of ten-years of a burn outreach program. Our focus was on clinical data on burn care within one region of Ukraine. We assessed knowledge of burn prevention/first aid utilizing a large survey, analyzed clinical data from our outreach clinic and telemedicine program, and analyzed data within a newly created burn repository within Ukraine.

RESULTS

A national burn prevention policy has been implemented through our efforts along with a burn prevention program. Educational efforts have led to improvements of major complication rates (wound infection [7% vs. 16%], pneumonia [2.4% vs. 0.3%], sepsis [1.6% vs. 0.6%], UTI [2% vs. 0.6%], and cellulitis [11% vs. 3.4%]), respiratory support of acutely ill patients [1.3% vs. 0.4%], and blood transfusion triggers.

CONCLUSIONS

Broadly, our model could be an example of building sustainable outreach programs in resource-constrained environments. Through collaboration with local healthcare providers, we have developed and implemented an outreach program in a resource-constrained environment.

Packed Red Blood Cell Transfusion Modulates Myeloid Dendritic Cell Activation and Inflammatory Response In Vitro

Transfusion of packed red blood cells (PRBCs) modulates patients' immune responses and clinical outcomes; however, the underpinning mechanism(s) remain unknown. The potential for PRBC to modulate myeloid dendritic cells (mDC) and blood DC antigen 3 was assessed using an in vitro transfusion model. In parallel, to model processes activated by viral or bacterial infection, toll-like receptor agonists polyinosinic:polycytidylic acid or lipopolysaccharide were added. Exposure to PRBC upregulated expression of CD83 and downregulated CD40 and CD80 on both DC subsets, and it suppressed production of interleukin (IL)-6, IL-8, IL-12, tumor necrosis factor-α, and interferon-gamma-inducible protein-10 by these cells. Similar effects were observed when modeling processes activated by concurrent infection. Furthermore, exposure to PRBC at date of expiry was associated with more pronounced effects in all assays. Our study suggests PRBC have an impact on recipient DC function, which may result in failure to establish an appropriate immune response, particularly in patients with underlying infection.

Perioperative Management of Bleeding and Transfusion for Lung Transplantation

Perioperative allogeneic blood product transfusion is common in lung transplantation and has various implications on the short- and long-term outcomes of lung recipients. This review summarizes the effect of transfusion on outcomes including primary graft dysfunction, chronic lung allograft dysfunction, and all-cause mortality. We outline known risk factors for increased transfusion requirement in lung transplantation and present current evidence regarding the effect of hemostatic agents including antifibrinolytics, recombinant factor VII, and prothrombin complex concentrates. Finally, we highlight the roles of point-of-care coagulation testing and goal-directed transfusion strategies in reducing transfusion requirements in lung transplantation.

Predictors of postinjury acute respiratory distress syndrome: Lung injury persists in the era of hemostatic resuscitation

BACKGROUND

Acute respiratory distress syndrome (ARDS) following trauma is historically associated with crystalloid and blood product exposure. Advances in resuscitation have occurred over the last decade, but their impact on ARDS is unknown. We sought to investigate predictors of postinjury ARDS in the era of hemostatic resuscitation.

METHODS

Data were prospectively collected from arrival to 28 days for 914 highest-level trauma activations who required intubation and survived more than 6 hours from 2005 to 2016 at a Level I trauma center. Patients with ratio of partial pressure of oxygen to fraction of inspired oxygen of 300 mmHg or less during the first 8 days were identified. Two blinded expert clinicians adjudicated all chest radiographs for bilateral infiltrates in the first 8 days. Those with left-sided heart failure detected were excluded. Multivariate logistic regression was used to define predictors of ARDS.

RESULTS

Of the 914 intubated patients, 63% had a ratio of partial pressure of oxygen to fraction of inspired oxygen of 300 or less, and 22% developed ARDS; among the ARDS cases, 57% were diagnosed early (in the first 24 hours), and 43% later. Patients with ARDS diagnosed later were more severely injured (ISS 32 vs. 20, p = 0.001), with higher rates of blunt injury (84% vs. 72%, p = 0.008), chest injury (58% vs. 36%, p < 0.001), and traumatic brain injury (72% vs. 48%, p < 0.001) compared with the no ARDS group. In multivariate analysis, head/chest Abbreviated Injury Score scores, crystalloid from 0 to 6 hours, and platelet transfusion from 0 to 6 hours and 7 to 24 hours were independent predictors of ARDS developing after 24 hours.

CONCLUSIONS

Blood and plasma transfusion were not independently associated with ARDS. However, platelet transfusion was a significant independent risk factor. The role of platelets warrants further investigation but may be mechanistically explained by lung injury models of pulmonary platelet sequestration with peripheral thrombocytopenia.

LEVEL OF EVIDENCE

Prognostic study, level IV.

The European guideline on management of major bleeding and coagulopathy following trauma: fifth edition

BACKGROUND

Severe traumatic injury continues to present challenges to healthcare systems around the world, and post-traumatic bleeding remains a leading cause of potentially preventable death among injured patients. Now in its fifth edition, this document aims to provide guidance on the management of major bleeding and coagulopathy following traumatic injury and encourages adaptation of the guiding principles described here to individual institutional circumstances and resources.

METHODS

The pan-European, multidisciplinary Task Force for Advanced Bleeding Care in Trauma was founded in 2004, and the current author group included representatives of six relevant European professional societies. The group applied a structured, evidence-based consensus approach to address scientific queries that served as the basis for each recommendation and supporting rationale. Expert opinion and current clinical practice were also considered, particularly in areas in which randomised clinical trials have not or cannot be performed. Existing recommendations were re-examined and revised based on scientific evidence that has emerged since the previous edition and observed shifts in clinical practice. New recommendations were formulated to reflect current clinical concerns and areas in which new research data have been generated.

RESULTS

Advances in our understanding of the pathophysiology of post-traumatic coagulopathy have supported improved management strategies, including evidence that early, individualised goal-directed treatment improves the outcome of severely injured patients. The overall organisation of the current guideline has been designed to reflect the clinical decision-making process along the patient pathway in an approximate temporal sequence. Recommendations are grouped behind the rationale for key decision points, which are patient- or problem-oriented rather than related to specific treatment modalities. While these recommendations provide guidance for the diagnosis and treatment of major bleeding and coagulopathy, emerging evidence supports the author group's belief that the greatest outcome improvement can be achieved through education and the establishment of and adherence to local clinical management algorithms.

CONCLUSIONS

A multidisciplinary approach and adherence to evidence-based guidance are key to improving patient outcomes. If incorporated into local practice, these clinical practice guidelines have the potential to ensure a uniform standard of care across Europe and beyond and better outcomes for the severely bleeding trauma patient.

Nationwide cohort study of independent risk factors for acute respiratory distress syndrome after trauma

Background

The primary objective of this study was to evaluate the effect of specific direct and indirect factors that accounted, in trauma patients, for the development of acute respiratory distress syndrome (ARDS) and mortality in patients with ARDS.

Methods

We performed a retrospective cohort study of patients from the National Trauma Data Bank. Multilevel mixed-effects logistic regression was used with the development of ARDS as the primary and mortality in patients with ARDS as the secondary outcome measures. We compared trauma patients with versus without thoracic (direct) and extrathoracic (indirect) risk factors, using patient demographics, physiologic, and anatomic injury severity as covariates. Subset analysis was performed for patients with trauma-induced lung contusion (TILC) and for patients with minor (Injury Severity Score [ISS] ≤15) injury.

Results

A total of 2 998 964 patients were studied, of whom 28 597 developed ARDS. From 2011 to 2014, the incidence of ARDS decreased; however, mortality in patients with ARDS has increased. Predictors of ARDS included direct thoracic injury (TILC, multiple rib fractures, and flail chest), as well as indirect factors (increased age, male gender, higher ISS, lower Glasgow Coma Scale motor component score, history of cardiopulmonary or hematologic disease, and history of alcoholism or obesity). Patients with ARDS secondary to direct thoracic injury had a lower risk of mortality compared with patients with ARDS due to other mechanisms.

Discussion

Despite the decreasing incidence of trauma-induced ARDS, mortality in patients with ARDS has increased. Direct thoracic injury was the strongest predictor of ARDS. Knowing specific contributors to trauma-induced ARDS could help identify at-risk patients early in their hospitalization and mitigate the progression to ARDS and thereby mortality.

Level of evidence

Prognostic study, level III.

Outcomes After Massive Transfusion in Trauma Patients: Variability Among Trauma Centers

BACKGROUND

Exsanguinating trauma patients often require massive blood transfusion (defined as transfusion of 10 or more pRBC units within first 24 h). The aim of our study is to assess the outcomes of trauma patients receiving massive transfusion at different levels of trauma centers.

METHODS

Two-y (2013-2014) retrospective analysis of the American College of Surgeons Trauma Quality Improvement Program. We included all adult trauma patients who received massive transfusion (MT) of blood. Outcome measures were mortality, hospital length of stay, intensive care unit-free and ventilator-free days, blood products received, and complications.

RESULTS

We analyzed a total of 416,957 patients, of which 2776 met the inclusion criteria and included in the study. Mean age was 40.6 ± 20 y, 78.3% were males and 33.1% of the injuries were penetrating. Median injury severity score [IQR] was 29 [18-40], median [IQR] Glasgow Coma Scale 10[4-15]. Mean packed red blood cells transfusion in the first 24 h was 20 ± 13 units and mean plasma transfusion was 13 ± 11 units. Overall in-hospital mortality was 43.5%. Receiving MT in level I trauma center was independently associated with lower rates of mortality (odds ratio [OR]: 0.75 [0.46-0.96], P < 0.001). Higher injury severity score (OR: 1.020 [1.010-1.030], P < 0.001) and increased units of packed red blood cells transfused (OR: 1.067 [1.041-1.093], P < 0.001) were independently associated with increased mortality. However, there was no association between teaching status, age, gender, emergency department vitals, and units of plasma transfused.

CONCLUSIONS

Hemorrhage continues to remain one of the most common cause of death after trauma. Almost half of the patients who received massive transfusion died. Patients who receive massive blood transfusion in a level I trauma centers have improved survival compared with level II trauma centers.

Risk Factors for the Development of Acute Respiratory Distress Syndrome Following Hemorrhage

BACKGROUND

The Pragmatic Randomized Optimal Platelet and Plasma Ratios (PROPPR) study evaluated the effects of plasma and platelets on hemostasis and mortality after hemorrhage. The pulmonary consequences of resuscitation strategies that mimic whole blood, remain unknown.

METHODS

A secondary analysis of the PROPPR study was performed. Injured patients predicted to receive a massive transfusion were randomized to 1:1:1 versus 1:1:2 plasma-platelet-red blood cell ratios at 12 Level I North American trauma centers. Patients with survival >24 h, an intensive care unit (ICU) stay, and a recorded PaO2/FiO2 (P/F) ratio were included. Acute respiratory distress syndrome (ARDS) was defined as a P/F ratio < 200, with bilateral pulmonary infiltrates, and adjudicated by investigators.

RESULTS

Four hundred fifty-four patients were reviewed (230 received 1:1:1, 224 1:1:2). Age, sex, injury mechanism, and regional abbreviated injury scale (AIS) scores did not differ between cohorts. Tidal volume, positive end-expiratory pressure, and lowest P/F ratio did not differ. No significant differences in ARDS rates (14.8% vs. 18.4%), ventilator-free (24 vs. 24) or ICU-free days (17.5 vs. 18), hospital length of stay (22 days vs. 18 days), or 30-day mortality were found (28% vs. 28%). ARDS was associated with blunt injury (OR 3.61 [1.53-8.81] P < 0.01) and increasing chest AIS (OR 1.40 [1.15-1.71] P < 0.01). Each 500 mL of crystalloid infused during hours 0 to 6 was associated with a 9% increase in the rate of ARDS (OR 1.09 [1.04-1.14] P < 0.01). Blood given at 0 to 6 or 7 to 24 h were not risk factors for lung injury.

CONCLUSION

Acute crystalloid exposure, but not blood products, is a potentially modifiable risk factor for the prevention of ARDS following hemorrhage.

Crosstalk signaling between alveoli and capillaries

Crosstalk signaling between the closely juxtaposed epithelial and endothelial membranes of pulmonary alveoli establishes the lung's immune defense against inhaled and blood-borne pathogens. The crosstalk can occur in a forward direction, as from alveolus to capillary, or in a reverse direction, as from capillary to alveolus. The crosstalk direction likely depends on the site at which pathogens first initiate signaling. Thus, forward crosstalk may occur when inhaled pathogens encounter the alveolar epithelium, while reverse crosstalk may result from interactions of blood-borne pathogens with the endothelium. Here, we review the factors that regulate these two directions of signaling.

Endotoxemia Results in Trapping of Transfused Red Blood Cells in Lungs with Associated Lung Injury

BACKGROUND

Red blood cell (RBC) transfusion is associated with organ failure, in particular in the critically ill. We hypothesized that endotoxemia contributes to increased trapping of RBCs in organs. Furthermore, we hypothesized that this effect is more pronounced following transfusion of stored RBCs compared with fresh RBCs.

METHODS

Adult male Sprague-Dawley rats were randomized to receive injection with lipopolysaccharide from E coli or vehicle and transfusion with fresh or stored biotinylated RBCs. After 24 h, the amount of biotinylated RBCs in organs was measured by flow cytometry, as well as the 24-h post-transfusion recovery. Markers of organ injury and histopathology of organs were assessed.

RESULTS

Endotoxemia resulted in systemic inflammation and organ injury. Following RBC transfusion, donor RBCs were recovered from the lung and kidney of endotoxemic recipients (1.2 [0.8-1.6]% and 2.2 [0.4-4.4]% of donor RBCs respectively), but not from organs of healthy recipients. Trapping of donor RBCs in the lung was associated with increased lung injury, but not with kidney injury. Stored RBCs induced organ injury in the spleen and yielded a lower 24-h post-transfusion recovery, but other effects of storage time were limited.

CONCLUSION

Endotoxemia results in an increased percentage of donor RBCs recovered from the lung and kidney, which is associated with lung injury following transfusion.

Hematocrit and impact of transfusion in patients receiving extracorporeal life support

Introduction: Increasing the hematocrit is considered to increase oxygen delivery to the patient, especially when hypoxic conditions exist and the patient may become more stable. The aim of this study was to evaluate the relationship between hematocrit and hospital mortality via subgroup analyses of trauma and non-trauma patients. Methods: The hospital length of stay (LOS) and LOS in the intensive care unit (ICU) and hospital after extracorporeal life support (ECLS) treatment of 81 patients were analyzed and compared. In-hospital survival until extracorporeal membrane oxygen (ECMO) weaning and hospital discharge were defined as the clinical outcome. Results: Significantly increased mortality, with a relative risk of 1.73 with a 95% confidence interval of 1.134 to 2.639, was identified in the group with an hematocrit greater than 31%. However, no significant differences in relative risk (95% confidence interval) of death for each group were found among groups with an hematocrit less than or equal to 25%, 26-28% and 29-31%. Additionally, no significant relationship between survival and median hematocrit level was observed at a significance level of 0.413 and an Exp (B) of 1.089 at a 95% confidence interval of 0.878 to 1.373 in binary logistic regression analysis; a model was established with a -2 log likelihood of 40.687 for the entire group of patients. Moreover, a significant increase in mortality was observed as the average number of transfusions per day in the hospital increased (significance level 0.024, Exp (B) 4.378, 95% confidence interval for Exp (B) 1.212 to 15.810). Conclusion: Because a variety of factors influence therapy, the indication for transfusion should be re-evaluated and adapted repeatedly on a case-by-case basis. Further studies are needed to demonstrate whether an acceptable outcome from ECLS device therapy can also be achieved with a low hematocrit and a restrictive indication for transfusion.

A model-based cost-effectiveness analysis of Patient Blood Management

BACKGROUND

Patient blood management (PBM) is a multidisciplinary concept focused on the management of anaemia, minimisation of iatrogenic blood loss and rational use of allogeneic blood products. The aims of this study were: (i) to analyse post-operative outcome in patients with liberal vs restrictive exposure to allogeneic blood products and (ii) to evaluate the cost-effectiveness of PBM in patients undergoing surgery.

MATERIALS AND METHODS

A systematic literature review and meta-analysis were performed to compare post-operative complications in predominantly non-transfused patients (restrictive transfusion group) and patients who received one to three units of red blood cells (liberal transfusion group). Outcome measures included sepsis with/without pneumonia, acute renal failure, acute myocardial infarction and acute stroke. In a second step, a health economic model was developed to calculate cost-effectiveness of PBM (PBM-arm vs control-arm) for simulated cohorts of 10,000 cardiac and non-cardiac surgical patients based on the results of the meta-analysis and costs.

RESULTS

Out of 478 search results, 22 studies were analysed in the meta-analysis. The pooled relative risk of any complication in the restrictive transfusion group was 0.43 for non-cardiac and 0.34 for cardiac surgical patients. In the simulation model, PBM was related to reduced complications (1,768 vs 1,245) and complication-related deaths (411 vs 304) compared to standard care. PBM-related costs of therapy exceeded costs of the control arm by € 150 per patient. However, total costs, including hospitalisation, were higher in the control-arm for both non-cardiac (€ 2,885.11) and cardiac surgery patients (€ 1,760.69). The incremental cost-effectiveness ratio including hospitalisation showed savings of € 30,458 (non-cardiac and cardiac surgery patients) for preventing one complication and € 128,023 (non-cardiac and cardiac surgery patients) for prevention of one complication-related death in the PBM-arm.

DISCUSSION

Our results indicate that PBM may be associated with fewer adverse clinical outcomes compared to control management and may, thereby, be cost-effective.

Interaction between peri-operative blood transfusion, tidal volume, airway pressure and postoperative ARDS: an individual patient data meta-analysis

Background

Transfusion of blood products and mechanical ventilation with injurious settings are considered risk factors for postoperative lung injury in surgical Patients.

Methods

A systematic review and individual patient data meta-analysis was done to determine the independent effects of peri-operative transfusion of blood products, intra-operative tidal volume and airway pressure in adult patients undergoing mechanical ventilation for general surgery, as well as their interactions on the occurrence of postoperative acute respiratory distress syndrome (ARDS). Observational studies and randomized trials were identified by a systematic search of MEDLINE, CINAHL, Web of Science, and CENTRAL and screened for inclusion into a meta-analysis. Individual patient data were obtained from the corresponding authors. Patients were stratified according to whether they received transfusion in the peri-operative period [red blood cell concentrates (RBC) and/or fresh frozen plasma (FFP)], tidal volume size [≤7 mL/kg predicted body weight (PBW), 7-10 and >10 mL/kg PBW] and airway pressure level used during surgery (≤15, 15-20 and >20 cmH₂O). The primary outcome was development of postoperative ARDS.

Results

Seventeen investigations were included (3,659 patients). Postoperative ARDS occurred in 40 (7.2%) patients who received at least one blood product compared to 40 patients (2.5%) who did not [adjusted hazard ratio (HR), 2.32; 95% confidence interval (CI), 1.25-4.33; P=0.008]. Incidence of postoperative ARDS was highest in patients ventilated with tidal volumes of >10 mL/kg PBW and having airway pressures of >20 cmH₂O receiving both RBC and FFP, and lowest in patients ventilated with tidal volume of ≤7 mL/kg PBW and having airway pressures of ≤15 cmH₂O with no transfusion. There was a significant interaction between transfusion and airway pressure level (P=0.002) on the risk of postoperative ARDS.

Conclusions

Peri-operative transfusion of blood products is associated with an increased risk of postoperative ARDS, which seems more dependent on airway pressure than tidal volume size.

Prolonged EVLP Using OCS Lung: Cellular and Acellular Perfusates

BACKGROUND

We report the ability to extend lung preservation up to 24 hours (24H) by using autologous whole donor blood circulating within an ex vivo lung perfusion (EVLP) system. This approach facilitates donor lung reconditioning in a model of extended normothermic EVLP. We analyzed comparative responses to cellular and acellular perfusates to identify these benefits.

METHODS

Twelve pairs of swine lungs were retrieved after cardiac arrest and studied for 24H on the Organ Care System (OCS) Lung EVLP platform. Three groups (n = 4 each) were differentiated by perfusate: (1) isolated red blood cells (RBCs) (current clinical standard for OCS); (2) whole blood (WB); and (3) acellular buffered dextran-albumin solution (analogous to STEEN solution).

RESULTS

Only the RBC and WB groups met clinical standards for transplantation at 8 hours; our primary analysis at 24H focused on perfusion with WB versus RBC. The WB perfusate was superior (vs RBC) for maintaining stability of all monitored parameters, including the following mean 24H measures: pulmonary artery pressure (6.8 vs 9.0 mm Hg), reservoir volume replacement (85 vs 1607 mL), and PaO2:FiO2 ratio (541 vs 223). Acellular perfusion was limited to 6 hours on the OCS system due to prohibitively high vascular resistance, edema, and worsening compliance.

CONCLUSIONS

The use of an autologous whole donor blood perfusate allowed 24H of preservation without functional deterioration and was superior to both RBC and buffered dextran-albumin solution for extended lung preservation in a swine model using OCS Lung. This finding represents a potentially significant advance in donor lung preservation and reconditioning.

A microengineered model of RBC transfusion-induced pulmonary vascular injury

Red blood cell (RBC) transfusion poses significant risks to critically ill patients by increasing their susceptibility to acute respiratory distress syndrome. While the underlying mechanisms of this life-threatening syndrome remain elusive, studies suggest that RBC-induced microvascular injury in the distal lung plays a central role in the development of lung injury following blood transfusion. Here we present a novel microengineering strategy to model and investigate this key disease process. Specifically, we created a microdevice for culturing primary human lung endothelial cells under physiological flow conditions to recapitulate the morphology and hemodynamic environment of the pulmonary microvascular endothelium in vivo. Perfusion of the microengineered vessel with human RBCs resulted in abnormal cytoskeletal rearrangement and release of intracellular molecules associated with regulated necrotic cell death, replicating the characteristics of acute endothelial injury in transfused lungs in vivo. Our data also revealed the significant effect of hemodynamic shear stress on RBC-induced microvascular injury. Furthermore, we integrated the microfluidic endothelium with a computer-controlled mechanical stretching system to show that breathing-induced physiological deformation of the pulmonary microvasculature may exacerbate vascular injury during RBC transfusion. Our biomimetic microsystem provides an enabling platform to mechanistically study transfusion-associated pulmonary vascular complications in susceptible patient populations.

[Complex pelvic traumas : data linkage of the German Pelvic Injury Register and the TraumaRegister DGU®]

BACKGROUND

Complex pelvic traumas, i.e., pelvic fractures accompanied by pelvic soft tissue injuries, still have an unacceptably high mortality rate of about 18 %.

PATIENTS AND METHODS

We retrospectively evaluated an intersection set of data from the TraumaRegister DGU® and the German Pelvic Injury Register from 2004-2009. Patients with complex and noncomplex pelvic traumas were compared regarding their vital parameters, emergency management, stay in the ICU, and outcome.

RESULTS

From a total of 344 patients with pelvic injuries, 21 % of patients had a complex and 79 % a noncomplex trauma. Complex traumas were significantly less likely to survive (16.7 % vs. 5.9 %). Whereas vital parameters and emergency treatment in the preclinical setting did not differ substantially, patients with complex traumas were more often in shock and showed acute traumatic coagulopathy on hospital arrival, which resulted in more fluid volumes and transfusions when compared to patients with noncomplex traumas. Furthermore, patients with complex traumas had more complications and longer ICU stays.

CONCLUSION

Prevention of exsanguination and complications like multiple organ dysfunction syndrome still pose a major challenge in the management of complex pelvic traumas.

Limited Blood Transfusions Are Safe in Orthopaedic Trauma Patients

OBJECTIVES

Controversy exists over association of blood transfusions with complications. The purpose was to assess effects of limited transfusions on complication rates and hospital course.

SETTING

Level 1 trauma center.

PATIENTS AND METHODS

Three hundred seventy-one consecutive patients with Injury Severity Score ≥16 underwent fixation of fractures of spine (n = 111), pelvis (n = 72), acetabulum (n = 57), and/or femur (n = 179). Those receiving >3 units of packed red blood cell were excluded.

MAIN OUTCOME MEASUREMENTS

Fracture type, associated injuries, treatment details, ventilation time, complications, and hospital stay were prospectively recorded.

RESULTS

Ninety-eight patients with 107 fractures received limited transfusion, and 119 patients with 123 fractures were not transfused. The groups did not differ in age, fracture types, time to fixation, or associated injuries. Lowest hematocrit was lower in the transfused group (22.8 vs. 30.0, P < 0.0001). Surgical duration (3:23 vs. 2:28) and estimated blood loss (462 vs. 211 mL) were higher in transfused patients (all P < 0.003). Pulmonary complications occurred in 12% of transfused and 4% of nontransfused, (P = 0.10). Mean days of mechanical ventilation (2.51 vs. 0.45), intensive care unit days (4.5 vs. 1.5) and total hospital stay (8.8 vs. 5.7) were higher in transfused patients (all P ≤ 0.006). After multivariate analysis, limited transfusion was associated with increased hospital and intensive care unit stays and mechanical ventilation time, but not with complications.

CONCLUSIONS

Patients receiving ≤3 units of packed red blood cell had lower hematocrit and greater surgical burden, but no difference in complications versus the nontransfused group. Limited blood transfusions are likely safe, excepting a possible association with longer mechanical ventilation times and hospital stays.

LEVEL OF EVIDENCE

Therapeutic level III. See Instructions for Authors for a complete description of levels of evidence.

The acute respiratory distress syndrome following isolated severe traumatic brain injury

BACKGROUND

Acute respiratory distress syndrome (ARDS) is common after traumatic brain injury (TBI) and is associated with worse neurologic outcomes and longer hospitalization. However, the incidence and associated causes of ARDS in isolated TBI have not been well studied.

METHODS

We performed a subgroup analysis of 210 consecutive patients with isolated severe TBI enrolled in a prospective observational cohort at a Level 1 trauma center between 2005 and 2014. Subjects required endotracheal intubation and had isolated severe TBI defined by a head Abbreviated Injury Scale (AIS) score of 3 or greater and AIS score lower than 3 in all other categories. ARDS within the first 8 days of admission was rigorously adjudicated using Berlin criteria. Regression analyses were used to test the association between predictors of interest and ARDS.

RESULTS

The incidence of ARDS in the first 8 days after severe isolated TBI was 30%. Patients who developed ARDS were administered more crystalloids (4.3 L vs. 3.5 L, p = 0.005) and blood products in the first 12 hours of admission. Patients with ARDS had significantly worse clinical outcomes measured at 28 days, including longer median intensive care unit and hospital stays (4 days vs. 13 days, p < 0.001, and 7.5 days vs. 14.5 days, p < 0.001, respectively). In unadjusted logistic regression analyses, the odds of developing ARDS were significantly associated with head AIS score (odds ratio [OR], 1.8; p = 0.018), male sex (OR, 2.9; p = 0.012), and early transfusion of platelets (OR, 2.8; p = 0.003). These associations were similar in a multivariate logistic regression model.

CONCLUSION

In the era of balanced hemostatic resuscitation practices, severity of head injury, male sex, early crystalloids, and early transfusion of platelets are associated with a higher risk of ARDS after severe isolated TBI. Early transfusion of platelets after severe TBI may be a modifiable risk factor for ARDS, and these findings invite further investigation into causal mechanisms driving this observed association.

LEVEL OF EVIDENCE

Prognostic/epidemiologic study, level III.

The European guideline on management of major bleeding and coagulopathy following trauma: fourth edition

BACKGROUND

Severe trauma continues to represent a global public health issue and mortality and morbidity in trauma patients remains substantial. A number of initiatives have aimed to provide guidance on the management of trauma patients. This document focuses on the management of major bleeding and coagulopathy following trauma and encourages adaptation of the guiding principles to each local situation and implementation within each institution.

METHODS

The pan-European, multidisciplinary Task Force for Advanced Bleeding Care in Trauma was founded in 2004 and included representatives of six relevant European professional societies. The group used a structured, evidence-based consensus approach to address scientific queries that served as the basis for each recommendation and supporting rationale. Expert opinion and current clinical practice were also considered, particularly in areas in which randomised clinical trials have not or cannot be performed. Existing recommendations were reconsidered and revised based on new scientific evidence and observed shifts in clinical practice; new recommendations were formulated to reflect current clinical concerns and areas in which new research data have been generated. This guideline represents the fourth edition of a document first published in 2007 and updated in 2010 and 2013.

RESULTS

The guideline now recommends that patients be transferred directly to an appropriate trauma treatment centre and encourages use of a restricted volume replacement strategy during initial resuscitation. Best-practice use of blood products during further resuscitation continues to evolve and should be guided by a goal-directed strategy. The identification and management of patients pre-treated with anticoagulant agents continues to pose a real challenge, despite accumulating experience and awareness. The present guideline should be viewed as an educational aid to improve and standardise the care of the bleeding trauma patients across Europe and beyond. This document may also serve as a basis for local implementation. Furthermore, local quality and safety management systems need to be established to specifically assess key measures of bleeding control and outcome.

CONCLUSIONS

A multidisciplinary approach and adherence to evidence-based guidance are key to improving patient outcomes. The implementation of locally adapted treatment algorithms should strive to achieve measureable improvements in patient outcome.

Red blood cells induce necroptosis of lung endothelial cells and increase susceptibility to lung inflammation

RATIONALE

Red blood cell (RBC) transfusions are associated with increased risk of acute respiratory distress syndrome (ARDS) in the critically ill, yet the mechanisms for enhanced susceptibility to ARDS conferred by RBC transfusions remain unknown.

OBJECTIVES

To determine the mechanisms of lung endothelial cell (EC) High Mobility Group Box 1 (HMGB1) release following exposure to RBCs and to determine whether RBC transfusion increases susceptibility to lung inflammation in vivo through release of the danger signal HMGB1.

METHODS

In vitro studies examining human lung EC viability and HMGB1 release following exposure to allogenic RBCs were conducted under static conditions and using a microengineered model of RBC perfusion. The plasma from transfused and nontransfused patients with severe sepsis was examined for markers of cellular injury. A murine model of RBC transfusion followed by LPS administration was used to determine the effects of RBC transfusion and HMGB1 release on LPS-induced lung inflammation.

MEASUREMENTS AND MAIN RESULTS

After incubation with RBCs, lung ECs underwent regulated necrotic cell death (necroptosis) and released the essential mediator of necroptosis, receptor-interacting serine/threonine-protein kinase 3 (RIP3), and HMGB1. RIP3 was detectable in the plasma of patients with severe sepsis, and was increased with blood transfusion and among nonsurvivors of sepsis. RBC transfusion sensitized mice to LPS-induced lung inflammation through release of the danger signal HMGB1.

CONCLUSIONS

RBC transfusion enhances susceptibility to lung inflammation through release of HMGB1 and induces necroptosis of lung EC. Necroptosis and subsequent danger signal release is a novel mechanism of injury following transfusion that may account for the increased risk of ARDS in critically ill transfused patients.

Transfusion transmitted diseases in perioperative and intensive care settings

Patients in the perioperative period and intensive care unit are commonly exposed to blood transfusion (BT). They are at increased risk of transfusion transmitted bacterial, viral and protozoal diseases. The risk of viral transmission has decreased steadily, but the risk of bacterial transmission remains same. Bacterial contamination is more in platelet concentrates than in red cells and least in plasma. The chances of sepsis, morbidity and mortality depend on the number of transfusions and underlying condition of the patient. Challenges to safe BT continue due to new emerging pathogens and various management problems. Strategies to restrict BT, optimal surgical and anaesthetic techniques to reduce blood loss and efforts to develop transfusion alternatives should be made. Literature search was performed using search words/phrases blood transfusion, transfusion, transfusion transmitted diseases, transfusion transmitted bacterial diseases, transfusion transmitted viral diseases, transfusion transmitted protozoal diseases or combinations, on PubMed and Google Scholar from 1990 to 2014.

Association of red blood cell transfusion and in-hospital mortality in patients admitted to the intensive care unit: a systematic review and meta-analysis

INTRODUCTION

Previous research has debated whether red blood cell (RBC) transfusion is associated with decreased or increased mortality in patients admitted to the intensive care unit (ICU). We conducted a systematic review and meta-analysis to assess the relationship of RBC transfusion with in-hospital mortality in ICU patients.

METHODS

We carried out a literature search on Medline (1950 through May 2013), Web of Science (1986 through May 2013) and Embase (1980 through May 2013). We included all prospective and retrospective studies on the association between RBC transfusion and in-hospital mortality in ICU patients. The relative risk for the overall pooled effects was estimated by random effects model. Sensitivity analyses were conducted to assess potential bias.

RESULTS

The meta-analysis included 28,797 participants from 18 studies. The pooled relative risk for transfused versus nontransfused ICU patients was 1.431 (95% CI, 1.105 to 1.854). In sensitivity analyses, the pooled relative risk was 1.211 (95% CI, 0.975 to 1.505) if excluding studies without adjustment for confounders, 1.178 (95% CI, 0.937 to 1.481) if excluding studies with relative high risk of bias, and 0.901 (95% CI, 0.622 to 1.305) if excluding studies without reporting hazard ratio (HR) or relative risk (RR) as an effect size measure. Subgroup analyses revealed increased risks in studies enrolling patients from all ICU admissions (RR 1.513, 95%CI 1.123 to 2.039), studies without reporting information on leukoreduction (RR 1.851, 95%CI 1.229 to 2.786), studies reporting unadjusted effect estimates (RR 3.933, 95%CI 2.107 to 7.343), and studies using odds ratio as an effect measure (RR 1.465, 95%CI 1.049 to 2.045). Meta-regression analyses showed that RBC transfusion could decrease risk of mortality in older patients (slope coefficient -0.0417, 95%CI -0.0680 to -0.0154).

CONCLUSIONS

There is lack of strong evidence to support the notion that ICU patients who receive RBC transfusion have an increased risk of in-hospital death. In studies adjusted for confounders, we found that RBC transfusion does not increase the risk of in-hospital mortality in ICU patients. Type of patient, information on leukoreduction, statistical method, mean age of patient enrolled and publication year of the article may account for the disagreement between previous studies.

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.

Increased trauma center volume is associated with improved survival after severe injury: results of a Resuscitation Outcomes Consortium study

OBJECTIVE

To investigate the relationship between trauma center volume and outcome.

BACKGROUND

The Resuscitation Outcomes Consortium is a network of 11 centers and 60 hospitals conducting emergency care research. For many procedures, high-volume centers demonstrate superior outcomes versus low-volume centers. This remains controversial for trauma center outcomes.

METHODS

This study was a secondary analysis of prospectively collected data from the Resuscitation Outcomes Consortium multicenter out-of-hospital Hypertonic Saline Trial in patients with Glasgow Coma Scale score of 8 or less (traumatic brain injury) or systolic blood pressure of 90 or less and pulse of 110 or more (shock). Regression analyses evaluated associations between trauma volume and the following outcomes: 24-hour mortality, 28-day mortality, ventilator-free days, Multiple Organ Dysfunction Scale incidence, worst Multiple Organ Dysfunction Scale score, and poor 6-month Glasgow Outcome Scale-Extended score.

RESULTS

A total of 2070 patients were evaluated: 1251 in the traumatic brain injury cohort and 819 in the shock cohort. Overall, 24-hour and 28-day mortality was 16% and 25%, respectively. For every increase of 500 trauma center admissions, there was a 7% decreased odds of 24-hour and 28-day mortality for all patients. As trauma center volume increased, nonorgan dysfunction complications increased, ventilator-free days increased, and worst Multiple Organ Dysfunction Scale score decreased. The associations with higher trauma center volume were similar for the traumatic brain injury cohort, including better neurologic outcomes at 6 months, but not for the shock cohort.

CONCLUSIONS

Increased trauma center volume was associated with increased survival, more ventilator-free days, and less severe organ failure. Trauma system planning and implementation should avoid unnecessary duplication of services.

The effect of age and clinical circumstances on the outcome of red blood cell transfusion in critically ill patients

Introduction

Whether red blood cell (RBC) transfusion is beneficial remains controversial. In both retrospective and prospective evaluations, transfusion has been associated with adverse, neutral, or protective effects. These varying results likely stem from a complex interplay between transfusion, patient characteristics, and clinical context. The objective was to test whether age, comorbidities, and clinical context modulate the effect of transfusion on survival.

Methods

By using the multiparameter intelligent monitoring in intensive care II database (v. 2.6), a retrospective analysis of 9,809 critically ill patients, we evaluated the effect of RBC transfusion on 30-day and 1-year mortality. Propensity score modeling and logistic regression adjusted for known confounding and assessed the independent effect of transfusion on 30-day and 1-year mortality. Sensitivity analysis was performed by using 3,164 transfused and non-transfused pairs, matched according the previously validated propensity model for RBC transfusion.

Results

RBC transfusion did not affect 30-day or 1-year mortality in the overall cohort. Patients younger than 55 years had increased odds of mortality (OR, 1.71; P < 0.01) with transfusion. Patients older than 75 years had lower odds of 30-day and 1-year mortality (OR, 0.70; P < 0.01) with transfusion. Transfusion was associated with worse outcome among patients undergoing cardiac surgery (OR, 2.1; P < 0.01). The propensity-matched population corroborated findings identified by regression adjustment.

Conclusion

A complex relation exists between RBC transfusion and clinical outcome. Our results show that transfusion is associated with improved outcomes in some cohorts and worse outcome in others, depending on comorbidities and patient characteristics. As such, future investigations and clinical decisions evaluating the value of transfusion should account for variations in baseline characteristics and clinical context.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-014-0487-z) contains supplementary material, which is available to authorized users.

Treatment of Rhizobium radiobacter bacteremia in a critically ill trauma patient

OBJECTIVE

To report the first case of Rhizobium radiobacter bacteremia in a critically ill trauma patient.

CASE SUMMARY

A 36-year-old female trauma patient hospitalized at The Regional Medical Center at Memphis developed bacteremia due to Rhizobium radiobacter on hospital day 9. The central line catheter tip culture from the same hospital day was negative. No source for the R radiobacter bacteremia was identified. Empirical and definitive antibiotic therapy consisted of cefepime 2 g intravenously every 8 hours for at total of 8 days. On completion of antibiotics, the patient demonstrated clinical resolution by immediate defervescence and gradual normalization of her white blood cell count. She demonstrated microbiologic success of therapy with negative blood cultures on hospital days 22, 34, 45, and 61. She was discharged on hospital day 80.

DISCUSSION

Rhizobium species are common soil and plant pathogens that rarely cause infections in humans. Previous reports of Rhizobium infections have been in immunocompromised patients; generally those with cancer or HIV infection. Intravenous catheters have commonly been cited as the source of infection. The trauma patient in this case constitutes a unique presentation of R radiobacter bacteremia when compared with other case reports. Her indwelling catheter was not the source of her infection, and her only identifiable risk factor for R radiobacter infection was hospitalization. However, she did possess potential reasons for development of an infection with an unusual organism such as R radiobacter. Potential immune modulating therapies included blood transfusions, opioid analgesics, benzodiazepines, general anesthetics, and surgical procedures. Finally, trauma itself has been associated with some degree of immunosuppression. All these issues may have placed the patient in this case at risk of an opportunistic infection like R radiobacter.

CONCLUSION

Based on this case, R radiobacter may be considered a potential pathogen causing bacteremia in critically ill trauma patients.

[Transfusion-related acute lung injury]

Transfusion-related acute lung injury (TRALI) developed into the leading cause of transfusion-related morbidity and mortality after the first description by Popovsky et al. approximately three decades ago. It was the most frequent reason for transfusion-related fatalities worldwide before implementation of risk minimization strategies by donor selection. Plasma-rich blood products, such as fresh frozen plasma and apheresis platelets seem to be the leading triggers of TRALI. Hypoxemia and development of pulmonary edema within 6 h of transfusion are the diagnostic criteria for TRALI. The differentiation between cardiac failure and other transfusion-related lung injuries, such astransfusion-associated circulatory overload ( TACO) is difficult and causal treatment is not available. Therapy is based on supportive measures, such as oxygen insufflationor mechanical ventilation. The exactly pathogenesis is still unknown but the most propagated hypothesis is the two-event-model. Neutrophils are primed by the underlying condition, e.g. sepsis or trauma during the first event and these primed neutrophils are activated by transfused leukoagglutinating antibodies (immunogen) or bioreactive mediators (non-immunogen) during the second-event. Transfusion of leukoagglutinating antibodies from female donors with one or more previous pregnancies is the most frequent reason. No more TRALI fatalities were reported after implementation of the donor selection in Germany in 2009.

Longer storage duration of red blood cells is associated with an increased risk of acute lung injury in patients with sepsis

Background

The storage duration of red blood cells transfused to critically ill patients is associated with increased morbidity and mortality. Whether the association exists between storage duration of red blood cells transfused to patients with sepsis and the risk of developing ALI/ARDS is unknown. We aimed to determine the association of the storage duration of red blood cells transfused to patients with sepsis and risk of developing acute lung injury in the subsequent 96 hours, with comparator trauma and nonsepsis/nontrauma groups.

Methods

We conducted a retrospective observational study of 96 transfused, critically ill patients with sepsis, 176 transfused, critically ill patients with traumatic injury, and 125 transfused, critically ill nontrauma, nonsepsis patients. The primary outcome was the development of ALI/ARDS up to 96 hours after transfusion.

Results

In 96 patients with sepsis, 49 (51%) patients developed ALI/ARDS. The median storage duration of transfused blood in the ALI/ARDS group was greater (24.5 days, interquartile range (IQR) 20–31) compared with the patients who did not develop ALI/ARDS (21 days, IQR 15–27, p = 0.018). Longer median storage duration was independently associated with an increased risk of developing ALI/ARDS in the subsequent 4 days (odds ratio 1.8, p = 0.028). The same association was not seen in the trauma or nonsepsis, nontrauma patients.

Conclusions

Transfusion of blood with longer median storage duration to patients with sepsis is associated with a higher risk of developing ALI up to 4 days after transfusion. This same association is not seen in other critically ill patient populations.

Application of the Berlin definition in PROMMTT patients: the impact of resuscitation on the incidence of hypoxemia

BACKGROUND

Acute lung injury following trauma resuscitation remains a concern despite recent advances. With the use of the PROMMTT study population, the risk of hypoxemia and potential modifiable risk factors are studied.

METHODS

Patients with survival for 24 hours or greater with at least one intensive care unit day were included in the analysis. Hypoxemia was categorized using the Berlin definition for adult respiratory distress syndrome: none (PaO₂-to-FIO₂ ratio [P/F] > 300 mm Hg), mild (P/F, 201-300 mm Hg), moderate (P/F, 101-200 mm Hg) or severe (P/F ≤ 100 mm Hg). The cohort was dichotomized into those with none or mild hypoxemia and those with moderate or severe injury. Early resuscitation was defined as that occurring 0 hour to 6 hours from arrival; late resuscitation was defined as that occurring 7 hours to 24 hours. Multivariate logistic regression models were developed controlling for age, sex, mechanisms of injury, arrival physiology, individual Abbreviated Injury Scale (AIS) scores, blood transfusions, and crystalloid administration.

RESULTS

Of the patients 58.7% (731 of 1,245) met inclusion criteria. Hypoxemia occurred in 69% (mild, 24%; moderate, 28%; severe, 17%). Mortality was highest (24%) in the severe group. During early resuscitation (0-6 h), logistic regression revealed age (odd ratio [OR], 1.02; 95% confidence interval [CI], 1.00-1.04), chest AIS score (OR, 1.31; 95% CI, 1.10-1.57), and intravenously administered crystalloid fluids given in 500 mL increments (OR, 1.12; 95% CI, 1.01-1.25) as predictive of moderate or severe hypoxemia. During late resuscitation, age (OR, 1.02; 95% CI, 1.00-1.04), chest AIS score (OR, 1.33; 95% CI, 1.11-1.59), and crystalloids given during this period (OR, 1.05; 95% CI, 1.01-1.10) were also predictive of moderate-to-severe hypoxemia. Red blood cell, plasma, and platelet transfusions (whether received during early or late resuscitation) failed to demonstrate an increased risk of developing moderate/severe hypoxemia.

CONCLUSION

Severe chest injury, increasing age, and crystalloid-based resuscitation, but not blood transfusions, were associated with increased risk of developing moderate-to-severe hypoxemia following injury.

High incidence of post-injury pneumonia in intensive care-treated trauma patients

INTRODUCTION

Trauma patients are susceptible to post-injury infections. We investigated the incidence, as well as risk factors for development of pneumonia in intensive care unit (ICU)-treated trauma patients. In addition, we report pathogens identified in patients that developed pneumonia.

METHODS

The study cohort consisted of 322 trauma patients admitted to the ICU at a level-one trauma centre following initial resuscitation. Patients 15 years or older with an ICU stay of more than 24 h were included. We investigated pre-hospital and hospital parameters during the first 24 h after admission and their possible association with pneumonia within 10 days of ICU admission.

RESULTS

Majority of the patients were male (78%) and the median age was 41 years. The overall degree of injury was high with a median Injury Severity Score (ISS) of 24. Overall 30-day mortality was 9%. Eighty-five (26%) patients developed pneumonia during their first 10 days in the ICU. Univariate logistic regression revealed that intubation in the field, shock, Glasgow Coma Scale (GCS) 3-8, major surgery within 24 h after admission, massive transfusion and ISS > 24 were all risk factors for subsequent development of pneumonia. In the multivariable model, only GCS 3-8 was identified as an independent risk factor. In 42 out of the 85 cases of pneumonia, the diagnosis was defined by significant growth of at least one pathogen where Enterobacteriaceae and Staphylococcus aureus were the most common.

CONCLUSIONS

Pneumonia is a common complication among ICU-treated trauma patients. Reduced consciousness is an independent risk factor for development of pneumonia after severe injury.

Post transfusion lung injury in the neonatal population

OBJECTIVE

The objective of this study was to examine the changes in level of respiratory support following transfusion in neonates who require intermediate or intensive care.

STUDY DESIGN

Data on respiratory support were collected retrospectively from the medical record before, during and after transfusion. Neonatal post transfusion lung injury (NPTLI) was defined as an increase in the highest mean airway pressure (MAP) of ≥2 cm H(2)O or FiO(2) >0.15 in the 6-h after transfusion that persisted from 6 to 18 h post transfusion.

RESULT

A total of 373 (330 packed red blood cell) transfusions were given to 108 infants. NPTLI occurred following 31 (8.3%) transfusions in 23 patients. During the first 6 h after transfusion, FiO2 or MAP was increased in 47 transfusions (12.6%) and the changes persisted in 31 transfusions (7.8%). Infants who developed NPTLI were less mature (27.1±0.7 vs 31.0±0.5 weeks; P=0.005) and of lower birth weight (1001±110 vs1692±104 g; P=0.001). Infants who developed NPTLI were more likely to develop necrotizing enterocolitis (6/24 vs 4/85; P=0.002) and die within 24 h of transfusion (5/22 vs 3/85; P=0.003).

CONCLUSION

In neonates receiving intensive or intermediate care, blood transfusion was associated with need for increased respiratory support in a significant number of cases. Development of NPTLI was associated with poorer outcomes.

Pulmonary complications of transfused blood components

Three transfusion complications are responsible for the majority of the morbidity and mortality in hospitalized patients. This article discusses the respiratory complications associated with these pathophysiologic processes, including definitions, diagnosis, mechanism, incidence, risk factors, clinical management, and strategies for prevention. It also explores how different patient populations and different blood components differentially affect the risk of these deadly transfusion complications. Lastly, the article discusses how health care providers can risk stratify individual patients or patient populations to determine whether a given transfusion is more likely to benefit or harm the patient based on the transfusion indication, risk, and expected result.

Blood utilization in patients with burn injury and association with clinical outcomes (CME)

BACKGROUND

Uncontrolled bleeding is an important cause of increased transfusion in burn victims; however, description of blood utilization patterns in the burn population is lacking.

STUDY DESIGN AND METHODS

We conducted a single-institution, retrospective cohort study to measure blood utilization in 89 consecutive burn patients with 15% to 65% total body surface area (TBSA) burn within 60 days of injury. We also evaluated the relationship of blood product utilization with clinical variables including anticoagulant usage and mortality.

RESULTS

We determined that: 1) the predictors for increased red blood cells (RBCs) and plasma transfusions were high TBSA burn and the use of argatroban anticoagulation (for suspected heparin-induced thrombocytopenia [HIT]); 2) TBSA burn and patient age were independent predictors of mortality, but not RBC or plasma transfusion; and 3) the incidence of symptomatic venous thromboembolic events is not uncommon (11.2%), although HIT is rare (1.1%).

CONCLUSION

Despite concerns about adverse correlation between increased number of transfusions and mortality in other clinical settings, we did not find this association in our study. However, we demonstrated that the type and intensity of anticoagulation carries substantial risk for increased RBC as well as plasma usage.

The association of early transfusion with acute lung injury in patients with severe injury

BACKGROUND

Packed red blood cell (PRBC) transfusion is associated with acute lung injury (ALI) development after trauma, but this risk may not be constant through time after trauma. We hypothesized that the relationship between PRBC delivery and ALI risk varies through time after injury.

METHODS

Data were collected prospectively from 1999 to 2006. Inclusion criteria include the following: older than 13 years, surgical intensive care unit admission, and Injury Severity Score of 16 or greater. Exclusion criteria included discharge/death within 24 hours of admission. Patients were followed up prospectively for ALI development for 5 days after trauma. Discrete time models were fit to test the association of timing of PRBC delivery with the development of ALI while controlling for patient demographics, resuscitation variables, Injury Severity Score, and Acute Physiology and Chronic Health Evaluation III scores.

RESULTS

At total of 602 patients were included. Median age was 33 years, 77% were male, and 50% were African American. Using a discrete time-survival model, the relation between transfusion and ALI development was found to vary by transfusion time window (p < 0.0001). The major effect of PRBC delivery on ALI risk occurred in the first 24 hours after trauma; this finding persisted in multivariable modeling (adjusted odds ratio, 1.07 per unit; 95% confidence interval, 1.02-1.11, p < 0.001). Cumulative incidence of ALI approached 50% in patients receiving 6 U of PRBC or more in the first 24 hours.

CONCLUSION

The association between PRBC transfusion and ALI development in patients with trauma is time dependent, with PRBC delivery in the first 24 hours after injury driving the overall relation. Each PRBC unit during this period increases odds of subsequent ALI development by 7%.

LEVEL OF EVIDENCE

Prognostic/epidemiologic study, level II.

Red blood cell clearance in inflammation

SUMMARY

Anemia is a frequently encountered problem in the critically ill patient. The inability to compensate for anemia includes several mechanisms, collectively referred to as anemia of inflammation: reduced production of erythropoietin, impaired bone marrow response to erythropoietin, reduced iron availability, and increased red blood cell (RBC) clearance. This review focuses on mechanisms of RBC clearance during inflammation. We state that phosphatidylserine (PS) expression in inflammation is mainly enhanced due to an increase in ceramide, caused by an increase in sphingomyelinase activity due to either platelet activating factor, tumor necrosis factor-α, or direct production by bacteria. Phagocytosis of RBCs during inflammation is mediated via RBC membrane protein band 3. Reduced deformability of RBCs seems an important feature in inflammation, also mediated by band 3 as well as by nitric oxide, reactive oxygen species, and sialic acid residues. Also, adherence of RBCs to the endothelium is increased during inflammation, most likely due to increased expression of endothelial adhesion molecules as well as PS on the RBC membrane, in combination with decreased capillary blood flow. Thereby, clearance of RBCs during inflammation shows similarities to clearance of senescent RBCs, but also has distinct entities, including increased adhesion to the endothelium.

An Epidemiological Study of Anemia and Renal Dysfunction in Patients Admitted to ICUs across the United States

The aims of this study were to determine the associations between anemia of critical illness, erythropoietin stimulating agents (ESA), packed red blood cell transfusions and varying degrees of renal dysfunction with mortality, and ICU- and hospital length of stay (LOS). This was a cross-sectional retrospective study of 5,314 ICU patients from USA hospitals. Hospital, patient demographics, and clinical characteristics were collected. Predictors of mortality and hospital and ICU LOS were evaluated using multivariate logistic regression models. The mean ICU admission hemoglobin in this study was 9.4 g/dL. The prevalence of ESA use was 13% and was associated with declining renal function; 26% of the ICU patients in this study received transfusion. ESA utilization was associated with 28% longer hospital LOS (P < 0.001). ICU LOS was increased by up to 18% in patients with eGFR rates of <30 and 30-59 mL/min/1.73 m(2), respectively (P < 0.05) but not in those receiving dialysis. Mortality was significantly associated with renal dysfunction and dialysis with odds ratios of 1.94, 2.66 and 1.40 for the dialysis, and eGFR rates of <30 and 30-59 and mL/min/1.73 m(2), respectively (P < 0.05). These data provide a snapshot of anemia treatment practices and outcomes in USA ICU patients with varying degrees of renal dysfunction.

Microvascular response to red blood cell transfusion in trauma patients

Trauma patients are often transfused allogeneic red blood cells (RBCs) in an effort to augment tissue oxygen delivery. However, the effect of RBC transfusion on microvascular perfusion in this patient population is not well understood. To this end, we investigated the effect of RBC transfusion on sublingual microvascular perfusion in trauma patients. Sublingual microcirculation was imaged at bedside with a sidestream dark-field illumination microscope before and after transfusion of one RBC unit in hemodynamically stable, anemic trauma patients. The perfused proportion of capillaries (PPC) before and after transfusion was determined, and the percent change in capillary perfusion following transfusion (ΔPPC) calculated. Sublingual microcirculation was observed in 30 patients. Mean age was 47 (SD, 21) years, mean Injury Severity Score was 29 (SD, 16), and mean pretransfusion hemoglobin was 7.5 (SD, 0.9) g/dL. No patients had a mean arterial pressure of less than 65 mmHg (mean, 89 [SD, 17] mmHg) or lactate of greater than 2.5 mmol/L (mean, 1.1 [SD, 0.3] mmol/L). Following transfusion, ΔPPC ranged from +68% to -36% and was found to inversely correlate significantly with pretransfusion PPC (Spearman r = -0.63, P = 0.0002). Pretransfusion PPC may be selectively deranged in otherwise stable trauma patients. Patients with relatively altered baseline PPC tend to demonstrate improvement in perfusion following transfusion, whereas those with relatively normal perfusion at baseline tend to demonstrate either no change or, in fact, a decline in PPC. Bedside sublingual imaging may have the potential to detect subtle perfusion defects and ultimately inform clinical decision making with respect to transfusion.

The age of transfused blood predicts hematocrit response among critically ill surgical patients

BACKGROUND

In vitro data suggest that erythrocytes undergo storage time-dependent degradation, eventuating in hemolysis. We hypothesize that transfusion of old blood, as compared with newer blood, results in a smaller increment in hematocrit.

METHODS

We performed an analysis of packed red blood cell transfusions administered in the surgical intensive care unit. Age of blood was analyzed as continuous, dichotomized at 14 days (old vs new), and grouped by weeks old.

RESULTS

A total of 136 U of packed red blood cells were given to 52 patients; 110 (80.9%) were 14 days old or more. A linear, inverse correlation was observed between the age of blood and the increment in hematocrit (r(2) = -.18, P = .04). The increment in hematocrit was greater after transfusion of new as compared with old blood (5.6% vs 3.5%, respectively; P = .005). A linear relationship also was observed between the age of transfused blood in weeks and the increment in hematocrit (P = .02).

CONCLUSIONS

There is an inverse relationship between the age of blood and the increment in hematocrit. The age of blood should be considered before transfusion of surgical patients with intensive care unit anemia.

Transfusion of packed red blood cells is not associated with improved central venous oxygen saturation or organ function in patients with septic shock

BACKGROUND

The exact role of packed red blood cell (PRBC) transfusion in the setting of early resuscitation in septic shock is unknown.

STUDY OBJECTIVE

To evaluate whether PRBC transfusion is associated with improved central venous oxygen saturation (ScvO(2)) or organ function in patients with severe sepsis and septic shock receiving early goal-directed therapy (EGDT).

METHODS

Retrospective cohort study (n=93) of patients presenting with severe sepsis or septic shock treated with EGDT.

RESULTS

Thirty-four of 93 patients received at least one PRBC transfusion. The ScvO(2) goal>70% was achieved in 71.9% of the PRBC group and 66.1% of the no-PRBC group (p=0.30). There was no difference in the change in Sequential Organ Failure Assessment (SOFA) score within the first 24 h in the PRBC group vs. the no-PRBC group (8.6-8.3 vs. 5.8-5.6, p=0.85), time to achievement of central venous pressure>8 mm Hg (732 min vs. 465 min, p=0.14), or the use of norepinephrine to maintain mean arterial pressure>65 mm Hg (81.3% vs. 83.8%, p=0.77).

CONCLUSIONS

In this study, the transfusion of PRBC was not associated with improved cellular oxygenation, as demonstrated by a lack of improved achievement of ScvO(2)>70%. Also, the transfusion of PRBC was not associated with improved organ function or improved achievement of the other goals of EGDT. Further studies are needed to determine the impact of transfusion of PRBC within the context of early resuscitation of patients with septic shock.

Sexual dimorphism in hematocrit response following red blood cell transfusion of critically ill surgical patients

The change in hematocrit (ΔHct) following packed red blood cell (pRBCs) transfusion is a clinically relevant measurement of transfusion efficacy that is influenced by post-transfusion hemolysis. Sexual dimorphism has been observed in critical illness and may be related to gender-specific differences in immune response. We investigated the relationship between both donor and recipient gender and ΔHct in an analysis of all pRBCs transfusions in our surgical intensive care unit (2006–2009). The relationship between both donor and recipient gender and ΔHct (% points) was assessed using both univariate and multivariable analysis. A total of 575 units of pRBCs were given to 342 patients; 289 (49.9%) donors were male. By univariate analysis, ΔHct was significantly greater for female as compared to male recipients (3.81% versus 2.82%, resp., P < 0.01). No association was observed between donor gender and ΔHct, which was 3.02% following receipt of female blood versus 3.23% following receipt of male blood (P = 0.21). By multivariable analysis, recipient gender remained associated significantly with ΔHct (P < 0.01). In conclusion, recipient gender is independently associated with ΔHct following pRBCs transfusion. This association does not appear related to either demographic or anthropomorphic factors, raising the possibility of gender-related differences in recipient immune response to transfusion.

Red blood cell transfusion in the critically ill patient

Red blood cell (RBC) transfusion is a common intervention in intensive care unit (ICU) patients. Anemia is frequent in this population and is associated with poor outcomes, especially in patients with ischemic heart disease. Although blood transfusions are generally given to improve tissue oxygenation, they do not systematically increase oxygen consumption and effects on oxygen delivery are not always very impressive. Blood transfusion may be lifesaving in some circumstances, but many studies have reported increased morbidity and mortality in transfused patients. This review focuses on some important aspects of RBC transfusion in the ICU, including physiologic considerations, a brief description of serious infectious and noninfectious hazards of transfusion, and the effects of RBC storage lesions. Emphasis is placed on the importance of personalizing blood transfusion according to physiological endpoints rather than arbitrary thresholds.