Association of blood transfusion with increased mortality in myocardial infarction: a meta-analysis and diversity-adjusted study sequential analysis

Relationship between low hemoglobin levels and mortality in patients with septic shock

Background

Hemoglobin levels are a critical parameter for oxygen delivery in patients with shock. On comparing target hemoglobin levels upon transfusion initiation, the correlation between the severity of decrease in hemoglobin levels and patient outcomes remains unclear. We evaluated the association between initial hemoglobin levels and mortality in patients with septic shock treated with protocol-driven resuscitation bundle therapy at an emergency department.

Methods

Data of adult patients diagnosed with septic shock between June 2012 and December 2016 were extracted from a prospectively compiled septic shock registry at a single academic medical center. Patients were classified into four groups according to initial hemoglobin levels: ≥9.0 g/dl, 8.0-8.9 g/dl, 7.0-7.9 g/dl, and <7.0 g/dl. The primary endpoint was 90-day mortality.

Results

In total, 2,265 patients (male, 58.3%; median age, 70.0 years [interquartile range, 60 to 78 years]) with septic shock were included. For the four groups, 90-day mortality rates were as follows: 29.1%, 43.0%, 46.5%, and 46.9% for ≥9.0 g/dl (n=1,808), 8.0-8.9 g/dl (n=217), 7.0-7.9 g/dl (n=135), and <7.0 g/dl (n=105), respectively (P<0.001). Multivariate logistic regression showed that initial hemoglobin levels were an independent factor associated with 90-day mortality and mortality proportionally increased with decreasing hemoglobin levels (odds ratio [OR], 1.88; 95% confidence interval [CI], 1.36 to 2.61 for 8.0-8.9 g/dl; OR, 1.97; 95% CI, 1.31 to 2.95 for 7.0-7.9 g/dl; and OR, 2.35; 95% CI, 1.52 to 3.63 for <7.0 g/dl).

Conclusions

Low hemoglobin levels (<9.0 g/dl) were observed in approximately 20% of patients with septic shock, and the severity of decrease in these levels correlated with mortality.

Trends and outcomes of red blood cell transfusion in patients undergoing transcatheter aortic valve replacement in the United States

OBJECTIVES

To examine temporal trends, predictors, and outcomes of red blood cell (RBC) transfusion in patients undergoing transcatheter aortic valve replacement (TAVR) in the United States.

METHODS

We used the National Inpatient Sample databases to identify TAVR procedures performed between January 2012 and September 2015 in the United States. Patients were propensity matched (within the strata of overt and no bleeding) on the likelihood of receiving RBC transfusion, and in-hospital outcomes were compared between the 2 groups in the matched cohort.

RESULTS

Among 46,710 TAVR procedures performed during the study period, rates of RBC transfusion were 17.3% (95% confidence interval [CI], 16.1%-18.5%). RBC transfusion rates decreased significantly from 29.5% during the first quarter of 2012 to 10.8% during the third quarter of 2015 (P < .001). Older age, female sex, peripheral vascular disease, chronic kidney disease, anemia, coagulopathy, and fluid/electrolyte disorders were associated with increased odds, whereas elective admission, obesity, and endovascular access were associated with decreased odds of RBC transfusion. In the propensity-matched cohort (7995 pairs with and without RBC transfusion), RBC transfusion was associated with increased risk of in-hospital mortality, infection, and transient ischemic attack/stroke in patients without bleeding (odds ratio [OR]_Mortality, 2.29; 95% CI, 1.31-4.02; OR_Infection, 2.13; 95% CI, 1.03-4.39; OR_{Transient ischemic attack/Stroke,} 3.36; 95% CI, 1.52-7.45), but not in those with overt bleeding (OR_Mortality, 1.10; 95% CI, 0.68-1.48; OR_Infection, 0.80; 95% CI, 0.45-1.45; OR_{Transient ischemic attack/Stroke}, 1.16; 95% CI, 0.74-1.85); P_interaction < .05 for all.

CONCLUSIONS

RBC transfusion is associated with worse clinical outcomes in TAVR patients without bleeding, but not in those with overt bleeding. The utility and optimal threshold for RBC transfusion in TAVR patients, especially among those with overt bleeding, warrants further prospective investigation.

Causes and prevention of postoperative myocardial injury

Over the past few years non-cardiac surgery has been recognised as a serious circulatory stress test which may trigger cardiovascular events such as myocardial infarction, in particular in patients at high risk. Detection of these postoperative cardiovascular events is difficult as clinical symptoms often go unnoticed. To improve detection, guidelines advise to perform routine postoperative assessment of cardiac troponin. Troponin elevation - or postoperative myocardial injury - can be caused by myocardial infarction. However, also non-coronary causes, such as cardiac arrhythmias, sepsis and pulmonary embolism, may play a role in a considerable number of patients with postoperative myocardial injury. It is crucial to acquire more knowledge about the underlying mechanisms of postoperative myocardial injury because effective prevention and treatment options are lacking. Preoperative administration of beta-blockers, aspirin, statins, clonidine, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers, and preoperative revascularisation have all been investigated as preventive options. Of these, only statins should be considered as the initiation or reload of statins may reduce the risk of postoperative myocardial injury. There is also not enough evidence for intraoperative measures such blood pressure optimisation or intensified medical therapy once patients have developed postoperative myocardial injury. Given the impact, better preoperative identification of patients at risk of postoperative myocardial injury, for example using preoperatively measured biomarkers, would be helpful to improve cardiac optimisation.

Outcomes of Percutaneous Coronary Interventions in Patients With Anemia Presenting With Acute Coronary Syndrome

OBJECTIVE

To study the influence of anemia on long-term outcomes of patients with acute coronary syndrome undergoing percutaneous coronary intervention (PCI).

PATIENTS AND METHODS

The study included 5668 consecutive unique patients with acute coronary syndrome who underwent PCI at Mayo Clinic from January 1, 2004, through December 31, 2014. The patients were stratified on the basis of the presence (hemoglobin [Hgb] level, <13 g/dL in men and <12 g/dL in women) and severity (moderate to severe Hgb level, <11 g/dL in men and women) of pre-PCI anemia and compared with patients without anemia. The primary outcomes were in-hospital and long-term all-cause mortality after balancing baseline comorbidities using the inverse propensity weighting method.

RESULTS

Unadjusted all-cause in-hospital mortality (4.6% [84 of 1831] vs 2.0% [75 of 3837]) and 5-year follow-up mortality (44.4% [509] vs 15.4% [323]) were higher in patients with anemia than in those without anemia (P<.001 for both). After applying inverse propensity weighting analysis, the all-cause in-hospital mortality (2.0% [37] vs 2.0% [75]; P=.85) and 5-year mortality (17.8% [203] vs 15.4% [323]; P=.05) were not significantly different between patients with and without anemia; however, there were higher rates of all-cause 5-year mortality in patients with moderate to severe anemia (22.3% [113] vs 15.4% [323]; P<.001) compared with patients without anemia. The trend in 5-year mortality was driven by increased noncardiac mortality in patients with anemia (10.2% [91] vs 7.1% [148]; P=.04) and moderate to severe anemia (10.4% [52] vs 7.1% [148]; P=.006) when compared with nonanemic patients.

CONCLUSION

After accounting for differences in risk profiles of anemic and nonanemic patients, anemia appeared to be an independent risk factor for increased long-term all-cause and noncardiac mortality.

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

OBJECTIVES

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

DESIGN

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Red blood cell transfusion in patients with ST-elevation myocardial infarction-a meta-analysis of more than 21,000 patients

BACKGROUND

Red blood cell transfusion remains controversial in patients with acute coronary syndromes and particularly in patients with ST-elevation myocardial infarction (STEMI).

METHODS

We systematically searched PubMed, Cochrane, EMBASE, and Web of Science for studies published until January 2017 describing the outcomes in patients with STEMI who received red blood cell transfusion, compared with patients who did not.

RESULTS

A total of 21,770 patients with STEMI from 5 cohort studies were included in the meta-analysis, 984 (4.5%) received red blood cell transfusion and 20,786 (95.4%) did not. Red blood cell transfusion was associated with a higher risk of in-hospital and long-term mortality, emergency repeated percutaneous coronary intervention (PCI), reinfarction rate, stroke rate, and heart failure. The group with red blood cell transfusion had a slightly higher incidence of diabetes mellitus and hypertension, but a lower incidence of smoking. The two groups had the same incidence of prior myocardial infarction, prior coronary artery bypass graft surgery and malignancy. Prior heart failure, prior stroke and prior PCI were more frequent in the group that had received red blood cell transfusion. The mean nadir haemoglobin was 8.5 ± 0.1 g/dl in the group with red blood cell transfusion and 12.5 ± 0.4 g/dl in the control group, p < 0.001.

CONCLUSIONS

Red blood cell transfusion increases the morbidity and mortality in patients with STEMI. This difference could not be explained by the higher morbidity in the red blood cell transfusion group alone. Further randomised controlled trials are required to provide a reliable haemoglobin threshold for these patients.

Emergency Medicine Evaluation and Management of Anemia

Anemia is a common condition and is diagnosed on laboratory assessment. It is defined by abnormally low hemoglobin concentration or decreased red blood cells. Several classification systems exist. Laboratory markers provide important information. Acute anemia presents with symptoms owing to acute blood loss; chronic anemia may present with worsening fatigue, dyspnea, lightheadedness, or chest pain. Specific treatments depend on the underlying anemia and etiology. Iron is an alternative treatment for patients with microcytic anemia owing to iron deficiency. Hyperbaric oxygen is an option for alternative rescue therapy. Most patients with chronic anemia may be discharged with follow-up if hemodynamically stable.

Anemia and acute coronary syndrome: current perspectives

Reference hemoglobin (Hb) values for the definition of anemia are still largely based on the 1968 WHO Scientific Group report, which established a cutoff value of <13 g/dL for adult men and <12 g/dL for adult nonpregnant women. Subsequent studies identified different normal values according to race and age. Estimated prevalence of anemia on admission in the setting of an acute coronary syndrome (ACS) is between 10% and 43% of the patients depending upon the specific population under investigation. Furthermore, up to 57% of ACS patients may develop hospital-acquired anemia (HAA). Both anemia on admission and HAA are associated with worse short- and long-term mortality, even if different mechanisms contribute to their prognostic impact. Baseline anemia can usually be traced back to preexisting disease that should be specifically investigated and corrected whenever possible. HAA is associated with clinical characteristics, medical therapy and interventional procedures, all eliciting cardiovascular adaptive response that can potentially worsen myocardial ischemia. The intrinsic fragility of anemic patients may limit aggressive medical and interventional therapy due to an increased risk of bleeding, and could independently contribute to worse outcome. However, primary angioplasty for ST elevation ACS should not be delayed because of preexisting (and often not diagnosed) anemia; delaying revascularization to allow fast-track anemia diagnosis is usually feasible and justified in non-ST-elevation ACS. Besides identification and treatment of the underlying causes of anemia, the only readily available means to reverse anemia is red blood cell transfusion. The adequate transfusion threshold is still being debated, although solid evidence suggests reserving red blood cell transfusions for patients with Hb level <8 g/dL and considering it in selected cases with Hb levels of between 8 and 10 g/dL. No evidence supports the use of iron supplements and erythropoiesis-stimulating agents in the setting of ACS.

Red blood cell transfusion and outcomes in acute pulmonary embolism

BACKGROUND AND OBJECTIVE

Blood transfusion has been associated with adverse outcomes in certain conditions. This study investigates the prevalence and outcomes of red blood cell (RBC) transfusion in patients with acute pulmonary embolism (PE).

METHODS

Retrospective study of consecutive patients from 2000 to 2012 admitted to a tertiary hospital with a primary diagnosis of acute PE. Transfusion status during the hospital admission was ascertained. Mortality was tracked from a state-wide death database and analysed using multivariable modelling.

RESULTS

A total of 73 patients (5% of all patients admitted with PE) received RBC transfusion during their admission. These patients were significantly older, had more co-morbidities, worse haemodynamics, higher simplified pulmonary embolism severity index scores, and lower plasma sodium and haemoglobin (Hb) levels at admission. Unadjusted mortality for the transfused group was significantly higher at 30-day (19% vs 4%, P < 0.001) and 6-month (40% vs 10%, P < 0.001) follow-up. Multivariable modelling showed RBC transfusion to be a significant independent predictor of mortality at 30-day (odds ratio 3.06, 95% CI: 1.17-8.01, P = 0.02) and 6-month (hazard ratio (HR) 1.97, 95% CI: 1.12-3.46, P = 0.02). Sensitivity analysis confirmed that transfused patients had higher mortality than non-transfused patients in the subgroup of patients with Hb <100 g/L.

CONCLUSION

RBC transfusion in patients hospitalized with acute PE is rare and appears to be associated with increased risk of short- and long-term mortality, independent of Hb level on admission. This finding underscores the need for future randomized controlled studies on the impact of RBC transfusion in the management of patients admitted with acute PE. [Correction added on 4 May 2018, after first online publication: the word 'serum' was changed to 'plasma' throughout the article where appropriate.].

Blood Transfusion in Elderly Patients with Acute Myocardial Infarction: Data from the RICO Survey

BACKGROUND

Red blood cell transfusion benefit during acute myocardial infarction remains unclear in the elderly. We aimed to assess the transfusion impact on 1-year mortality in acute myocardial infarction patients aged ≥65 years, according to their age and hemoglobin nadir.

METHODS

We included 3316 consecutive patients with acute myocardial infarction aged ≥65 years from the "obseRvatoire des Infarctus de Côte d'Or" (RICO) survey. They were categorized according to their hemoglobin nadir (≤8, >8 to ≤10, and >10 g/dL) and age (<80 or ≥80 years).

RESULTS

A total of 1906 patients (57%) were 65-79 years old, and 1410 (43%) were aged ≥80 years, of whom 103 (5%) and 145 (10%) patients received red blood cell transfusion, respectively (P < .001). In Cox regression analysis, transfusion was associated with increased 1-year mortality for hemoglobin nadir >10 g/dL but no significant effect for hemoglobin nadir between 8 and 10 g/dL. When hemoglobin nadir was ≤8 g/dL, transfusion did not influence 1-year mortality for younger patients (65-79 years). However, for older patients (≥80 years), transfusion was associated with lower mortality (hazard ratio 0.43 [95% confidence interval, 0.22-0.86], P = .016).

CONCLUSION

Among older patients with acute myocardial infarction, the effect of transfusion was largely dependent on hemoglobin threshold and age. Transfusion was associated with increased 1-year mortality when hemoglobin nadir was >10 g/dL. However, in patients aged ≥80 years with hemoglobin nadir <8 g/dL, transfusion was associated with a 50% reduction in 1-year mortality.

Impact of red blood cell transfusion on acute coronary syndrome: a meta-analysis

The impact of red blood cell transfusion on outcomes in patients with acute coronary syndrome is controversial. Pubmed, EMBASE, and Cochrane Library were searched for studies of red blood cell transfusion and acute coronary syndrome that were published in any language, from January 1, 1966, to April 1, 2016. We analyzed 17 observational studies, of 2,525,550 subjects. We conducted a systematic review with meta-analysis of studies assessing the association between blood transfusion and the risk for all-cause mortality and reinfarction. The search yielded 17 observational studies, of 2,525,550 subjects, during a study follow-up period, ranging from 30 days to 5 years. Red blood cell transfusion compared with no blood transfusion is associated with higher short- and long-term all-cause mortality as well as reinfarction rates (adjusted RR 2.23; 95% CI 1.47-3.39; HR 1.93; 95% CI 1.12-3.34; RR 2.61; 95% CI 2.17-3.14, respectively). In hemoglobin-stratified analyses, a graded association between red blood cell transfusion and mortality was observed, transfusion and risk of all-cause mortality was borderline significant at hemoglobin levels below 8.0 g/dL (RR 0.52; 95% CI 0.25-1.06), and was associated with an increased risk of mortality at a hemoglobin above 10 g/dL (RR 3.34; 95% CI 2.25-4.97). Red blood cell transfusion was associated with an increased risk of short- and long-term mortality as well as myocardial reinfarction. However, transfusion appeared to have beneficial or neutral effects on mortality at hemoglobin levels below 8.0 g/dL, and harmful effects above 10 g/dL. A large definitive randomized controlled trial addressing this issue is urgently required.

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.

The Effect of Diagnostic Blood Loss on Anemia and Transfusion Among Postoperative Patients With Congenital Heart Disease in a Pediatric Intensive Care Unit

PURPOSE

To evaluate whether diagnostic blood loss can lead to anemia and consequent blood transfusion among postoperative patients with congenital heart disease (CHD) in the pediatric intensive care unit (PICU).

DESIGN AND METHODS

This prospective observational study was conducted in a university-affiliated tertiary hospital between January and August 2016. CHD patients aged <12years, undergoing cardiac surgery, with a PICU stay >48h were included (n=205). Multivariate logistic regression analyses were used to determine the effect of diagnostic blood loss on anemia and transfusion.

RESULTS

The mean daily phlebotomy volume was 5.40±1.94mL/d during the PICU stay (adjusted for body weight, 0.63±0.36mL/kg/d). Daily volume/kg was associated with cyanotic CHD, Pediatric Risk of Mortality III score, and Pediatric Logistic Organ Dysfunction (PELOD)-2 score. In total, 101 (49.3%) patients presented with new or more severe anemia after admission to PICU, which was not associated with phlebotomy volume. Forty-one (20.0%) children received one or more RBC transfusions during their PICU stay. Multivariate analysis indicated that PELOD-2 score>5, new or more severe anemia, and daily volume/kg of phlebotomy >0.63mL/kg/d were significantly associated with transfusion after 48h of admission to PICU.

CONCLUSIONS

Our findings indicate that diagnostic blood loss is not related to postoperative anemia in children with CHD; however, this factor does correlate with blood transfusion, since it somewhat reflects the severity of illness.

PRACTICE IMPLICATIONS

Strategies should be applied to reduce diagnostic blood loss, as appropriate.

The Association between Arterial Oxygen Tension, Hemoglobin Concentration, and Mortality in Mechanically Ventilated Critically Ill Patients

Background:

Hypoxemia and anemia are common findings in critically ill patients admitted to Intensive Care Units. Both are independently associated with significant morbidity and mortality. However, the interaction between oxygenation and anemia and their impact on mortality in critically ill patients has not been clearly defined. We undertook this study to determine whether hemoglobin (Hb) level would modify the association between hypoxemia and mortality in mechanically ventilated critically ill patients.

Methods:

We performed a retrospective cohort study of all mechanically ventilated adult patients (aged >16 years) in the Australian and New Zealand Intensive Care Society Adult Patient Database (APD) admitted over a 10-year period. Multivariate hierarchical logistic regression was used to assess the relationship between hypoxemia and hospital mortality stratified by Hb.

Results:

Of 1,196,089 patients in the APD, 219,723 satisfied our inclusion and exclusion criteria. There was a linear negative relationship between hypoxemia and hospital mortality which was significantly modified when stratified by Hb. Hb independently increased the risk of mortality in patients with arterial oxygen tension <102.

Conclusions:

Hb is an effect modifier on the association between oxygenation and mortality.

Hemolysis in In-Date RBC Concentrates

OBJECTIVES

Hemolysis is one of the most prominent changes that occur during the liquid storage of RBCs in additive solution (AS), but most studies have measured hemolysis only on day 42.

METHODS

Prestorage leukoreduced RBCs in AS-1 and AS-3 were studied, one group on day 42 and a second group between day 0 and day 40. Each product was sampled for direct measurement of supernatant hemoglobin and hematocrit.

RESULTS

Ninety day 42 and 218 day 7 to day 39 RBCs showed a mean ± SD supernatant hemoglobin of 75 ± 100 vs 25.5 ± 16 mg/dL respectively (P < .01). Supernatant hemoglobin correlated weakly with storage age (r = 0.2, P < .01) but more strongly with hematocrit (r = 0.4, P < .01).

CONCLUSIONS

There are minimal differences in supernatant hemoglobin until the final days of liquid storage when some high hematocrit RBCs show excessive hemolysis.

Gender differences in the association between discharge hemoglobin and 12-month mortality after acute myocardial infarction

BACKGROUND

Anemia at discharge in patients with acute myocardial infarction is associated with poor prognosis; whether this differs in women and men or if there is a threshold value at which these relationships change is unknown.

HYPOTHESIS

Women have a lower discharge hemoglobin (Hb) at which outcomes worsen.

METHODS

We identified patients with acute myocardial infarction in the TRIUMPH registry between 2005 and 2008. In multivariable models, we evaluated the relationship between discharge Hb and 12-month mortality and tested whether this relationship varied by gender. We assessed whether the relationship with discharge Hb values was nonlinear using a restricted cubic spline term.

RESULTS

Of 4243 patients with AMI, 32.9% were female. Mean admission Hb was 12.9 ± 1.9 g/dL in women and 14.5 ± 2.0 g/dL in men, with mean discharge Hb 11.4 ± 1.8 g/dL and 12.9 ± 1.9 g/dL, respectively. Lower discharge Hb was independently associated with increased mortality (P < 0.05). In multivariable models, discharge Hb decline was similarly associated with increased 12-month mortality in women and men (per 1-g/dL decrease Hb; women HR: 1.24, 95% CI: 1.09-1.42, P < 0.01; and men HR: 1.25, 95% CI: 1.13-1.37, P < 0.01; P for gender interaction = 0.99). The relationship between discharge Hb and 12-month mortality was linear (P for nonlinear spline term = 0.12).

CONCLUSIONS

Lower discharge Hb levels were similarly associated with increased 12-month mortality in women and men. These relationships are linear without a clear threshold, suggesting any decline in discharge Hb is associated with poor outcomes.

Impact of transfusion on patients with sepsis admitted in intensive care unit: a systematic review and meta-analysis

Red blood cell transfusion (RBCT) threshold in patients with sepsis remains a matter of controversy. A threshold of 7 g/dL for stabilized patients with sepsis is commonly proposed, although debated. The aim of the study was to compare the benefit and harm of restrictive versus liberal RBCT strategies in order to guide physicians on RBCT strategies in patients with severe sepsis or septic shock. Four outcomes were assessed: death, nosocomial infection (NI), acute lung injury (ALI) and acute kidney injury (AKI). Studies assessing RBCT strategies or RBCT impact on outcome and including intensive care unit (ICU) patients with sepsis were assessed. Two systematic reviews were achieved: first for the randomized controlled studies (RCTs) and second for the observational studies. MEDLINE, EMBASE, Web of Science Core Collection, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews and Clinical Trials.gov were analyzed up to March 01, 2015. Der Simonian and Laird random-effects models were used to report pooled odds ratios (ORs). Subgroup analyses and meta-regressions were performed to explore studies heterogeneity. One RCT was finally included. The restrictive RBCT strategy was not associated with harm or benefit compared to liberal strategy. Twelve cohort studies were included, of which nine focused on mortality rate. RBCT was not associated with increased mortality rate (overall pooled OR was 1.10 [0.75, 1.60]; I 2 = 57%, p = 0.03), but was associated with the occurrence of NI (2 studies: pooled OR 1.25 [1.04-1.50]; I 2 = 0%, p = 0.97), the occurrence of ALI (1 study: OR 2.75 [1.22-6.37]; p = 0.016) and the occurrence of AKI (1 study: OR 5.22 [2.1-15.8]; p = 0.001). Because there was only one RCT, the final meta-analyses were only based on the cohort studies. As a result, the safety of a RBCT restrictive strategy was confirmed, although only one study specifically focused on ICU patients with sepsis. Then, RBCT was not associated with increased mortality rate, but was associated with increased in occurrence of NI, ALI and AKI. Nevertheless, the data on RBCT in patients with sepsis are sparse and the high heterogeneity between studies prevents from drawing any definitive conclusions.

Electronic remote blood issue combined with a computer-controlled, automated refrigerator for major surgery in operating theatres at a distance from the transfusion service

BACKGROUND

The difficulty of supplying red blood cells within an adequate time to patients undergoing surgery is a known problem for transfusion services, particularly if the operating theater is located at some distance from the blood bank. The consequences frequently are that more blood is ordered than required; several units are allocated and issued; and unused units must be returned to the blood bank. Some sparse reports have demonstrated that remote blood issue systems can improve the efficiency of issuing blood.

STUDY DESIGN AND METHODS

This study describes a computer-controlled, self-service, remote blood-release system, combined with an automated refrigerator, installed in a hospital at which major surgery was performed, located 5 kilometers away from the transfusion service. With this system, red blood cell units were electronically allocated to patients immediately before release, when the units actually were needed. Two 2-year periods, before and after implementation of the system, were compared.

RESULTS

After implementation of the system, the ratio of red blood cell units returned to the transfusion service was reduced from 48.9% to 1.6% of the issued units (8852 of 18,090 vs. 182 of 11,152 units; p < 0.0001), and the issue-to-transfusion ratio was reduced from 1.96 to 1.02. An increase in the number of transfused red blood cell units was observed, probably mainly due to changes in the number and complexity of surgical procedures. No transfusion errors occurred in the two periods.

CONCLUSION

The current results demonstrate that the remote blood-release system is safe and useful for improving the efficiency of blood issue for patients in remote operating theatres.

Effects of red blood cell storage time on transfused patients in the ICU-protocol for a systematic review

BACKGROUND

Patients in the intensive care unit (ICU) are often anaemic due to blood loss, impaired red blood cell (RBC) production and increased RBC destruction. In some studies, more than half of the patients were treated with RBC transfusion. During storage, the RBC and the storage medium undergo changes, which lead to impaired transportation and delivery of oxygen and may also promote an inflammatory response. Divergent results on the clinical consequences of storage have been reported in both observational studies and randomised trials. Therefore, we aim to gather and review the present evidence to assess the effects of shorter vs. longer storage time of transfused RBCs for ICU patients.

METHODS

We will conduct a systematic review with meta-analyses and trial sequential analyses of randomised clinical trials, and also include results of severe adverse events from large observational studies. Participants will be adult patients admitted to an ICU and treated with shorter vs. longer stored RBC units. We will systematically search the Cochrane Library, MEDLINE, Embase, BIOSIS, CINAHL and Science Citation Index for relevant literature, and we will follow the recommendation by the Cochrane Collaboration and the Preferred Reporting Items for Systemtic Review and Meta-Analysis (PRISMA)-statement. We will assess the risk of bias and random errors, and we will use the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach to evaluate the overall quality of evidence.

CONCLUSION

We need a high-quality systematic review to summarise the clinical consequences of RBC storage time among ICU patients.

Anemia and Red Blood Cell Transfusion: Advances in Critical Care

Anemia is common in the intensive care unit (ICU), resulting in frequent administration of red blood cell (RBC) transfusions. Significant advances have been made in understanding the pathophysiology of anemia in the ICU, which is anemia of inflammation. This anemia is related to high hepcidin concentrations resulting in iron-restricted erythropoiesis, and decreased erythropoietin concentrations. A new hormone (erythroferrone) has been identified, which mediates hepcidin suppression to allow increased iron absorption and mobilization from iron stores. RBC transfusions are most commonly administered to ICU patients for treatment of anemia. All strategies to reduce anemia in the ICU should be implemented.

Mortality and cardiorespiratory complications in trochanteric femoral fractures: a ten year retrospective analysis

PURPOSE

Despite intense research and innovations in peri-operative management, a high mortality rate and frequent systemic complications in trochanteric femoral fractures persist. The aim of the present study was to identify predictive factors for mortality and cardio-respiratory complications after different treatment methods in a ten year period at a level I trauma centre.

METHODS

Retrospectively, all patients above 60 years of age with trochanteric femoral fracture between January 2000 and May 2011 were analyzed at a level I trauma centre. Demographic variables, comorbidities, and data regarding the surgical procedures, including required transfusions and post-operative complications, were evaluated, and the in-hospital mortality was recorded. The grade of osteoporosis was classified radiographically using the Singh index.

RESULTS

The in-hospital mortality rate was 8.2% among 437 patients (male/female ratio = 110/327, mean age = 81 years) with extramedullary open (n = 144), intramedullary (n = 166), and extramedullary minimally invasive (n = 125) procedures. Significant influential factors on in-hospital mortality were identified with binary logistic regression analysis: an age of ≥90 years (P = 0.011), male sex (P = 0.003), a high American Society of Anesthesiologists (ASA) grade (3-5, P = 0.042), and a high osteoporosis grade (Singh index 3-1, P = 0.011). A total of 21.5% of the study population suffered cardio-respiratory complications post-operatively. The specific mortality was 28.7% (P < 0.001), which was influenced by a high ASA grade (3-5, P = 0.002) and a high transfusion rate (P = 0.004). Minimally invasive locked plating was associated with increased cardio-respiratory complications (P = 0.031).

CONCLUSIONS

This study identified high patient age, distinctive comorbidities, male sex, and high osteoporosis grade as significant risk factors for increased in-hospital mortality in the treatment of trochanteric femoral fractures. Furthermore, high ASA grade and a liberal transfusion regime led to an increased incidence of cardio-respiratory complications. Patient-specific characteristics, especially osteoporosis grade and pre-existing medical conditions, may assist in the identification of high-risk patients and allow a patient-specific geriatric co-management plan.

Low vs. high haemoglobin trigger for transfusion in vascular surgery: protocol for a randomised trial

BACKGROUND

In patients with cardiovascular disease, guidelines for administration of red blood cells (RBC) are mainly based on studies outside the vascular surgical setting with the recommendation to use a haemoglobin (hb) trigger-level lower than by guidelines from The European Society for Vascular Surgery. Restricting RBC transfusion may affect blood O₂ transport with a risk for development of tissue ischaemia and postoperative complications.

METHODS

In a single-centre, open-label, assessor blinded trial, 58 vascular surgical patients (> 40 years of age) awaiting open surgery of the infrarenal aorta or infrainguinal arterial bypass surgery undergo a web-based randomisation to one of two groups: perioperative RBC transfusion triggered by hb < 8 g/dl or hb < 9.7 g/dl. Administration of fluid follows an individualised strategy by optimising cardiac stroke volume and near-infrared spectroscopy determines tissue oxygenation. Serious adverse event rates are: myocardial injury (troponin-I ≥ 45 ng/l or ischaemic electrocardiographic findings at day 30), acute kidney injury, death, stroke and severe transfusion reactions. A follow-up visit takes place 30 days after surgery and a follow-up of serious adverse events in the Danish National Patient Register within 90 days is pending.

DISCUSSION

This trial is expected to determine whether a RBC transfusion triggered by hb < 9.7 g/dl compared with hb < 8 g/dl results in adequate separation of postoperative hb levels, transfusion of more RBC units and maintains a higher tissue oxygenation. The results will inform the design of a multicentre trial for evaluation of important postoperative outcomes.

How do we reduce plasma transfusion in Rhode Island?

BACKGROUND

Plasma transfusions are given to patients with coagulopathy, either prophylactically, before an invasive procedure; or therapeutically, in the presence of active bleeding; and as an exchange fluid in therapeutic plasma exchange for disorders such as thrombotic thrombocytopenic purpura. There is consensus that many prophylactic plasma transfusions are non-efficacious, and the misdiagnosis of thrombotic thrombocytopenic purpura results in unnecessary therapeutic plasma exchange.

STUDY DESIGN AND METHODS

Beginning in 2001, programs to reduce plasma transfusion in the three major teaching hospitals in Rhode Island were initiated. The programs evolved through the establishment of guidelines, education for key prescribers of plasma, screening of plasma prescriptions, and engagement of individual prescribing physicians for out-of-guidelines prescriptions with modification or cancellation. Establishment of an in-house ADAMTS13 (ADAM metallopeptidase with thrombospondin type 1, motif 13) assay in 2013 was used to prevent therapeutic plasma exchange in patients with non-thrombotic thrombocytopenic purpura microangiopathy. Transfusion service data were gathered at the hospital level regarding blood component use, hospital data for discharges, inpatient mortality, and mean case-mix index, and, at the state level, for units of plasma shipped from the community blood center to in-state hospitals.

RESULTS

Between 2006 and 2016, a reduction in plasma use from 11,805 to 2677 units (a 77% decrease) was observed in the three hospitals and was mirrored in the state as a whole. This decline was not associated with any increase in red blood cell transfusion. Inpatient mortality either declined or was unchanged.

CONCLUSION

An active program focused on education and interdiction can achieve a large decrease in plasma transfusions without evidence of patient harm.

Prevalence and prognostic significance of anemia in patients presenting for ST-elevation myocardial infarction in a Tunisian center

BACKGROUND

Anemia on admission is a powerful predictor of major cardiovascular events in patients presenting for acute coronary syndromes. We sought to determine the prevalence and prognostic impact of anemia in patients presenting for ST-elevation myocardial infarction (STEMI).

METHODS

We analyzed data from a Tunisian retrospective single center STEMI registry. Patients were enrolled between January 1998 and October 2014. Anemic and nonanemic patients were compared for clinical and prognostic features and according to four prespecified hemoglobin level subgroups. In patients with severe anemia, factors associated with in-hospital death were studied.

RESULTS

A total of 1498 patients were enrolled. Mean age was 60.47 ± 12.7 years and prevalence of anemia was 36.6%. Anemic patients were more likely to be elderly, hypertensive, and diabetic in comparison to nonanemic patients. In-hospital mortality was significantly higher in anemic patients (14.9% vs. 5%, p < 0.001). Lower hemoglobin levels were significantly associated with a higher prevalence of heart failure on admission, cardiogenic shock, and in-hospital mortality (p < 0.001 for all). In univariate analysis, factors associated with in-hospital death in patients with severe anemia were hypertension (p = 0.044), heart failure on admission (p < 0.001), renal failure on admission (p < 0.001), and primary percutaneous coronary intervention (pPCI) use (p = 0.016). The absence of pPCI use was independently associated with in-hospital death in multivariate analysis (odds ratio = 2.22, 95% confidence interval: 1.07-4.76, p = 0.033).

CONCLUSION

According to this study, anemic patients presenting for STEMI have a higher in-hospital mortality rate. The absence of pPCI use was independently associated with in-hospital death.

Restrictive versus liberal blood transfusion in patients with coronary artery disease: a meta-analysis

OBJECTIVES

To compare clinical outcomes between restrictive versus liberal blood transfusion strategies in patients with coronary artery disease (CAD).

RESEARCH DESIGN AND METHODS

A literature search from January 1966 to May 2016 was performed in PubMed, EMBASE and Cochrane Library to find trials evaluating a restrictive hemoglobin transfusion trigger of ≤8 g/dL, compared with a more liberal trigger. Two study authors independently extracted data from the trials. The primary outcome was mortality and the secondary outcome was subsequent myocardial infarction. Relative risks (RRs) with their 95% confidence intervals (CIs) were assessed.

RESULTS

Six trials involving 133,058 participants were included in this study. Pooled results revealed no difference in mortality between the liberal transfusion and restrictive transfusions (RR = 1.17, 95% CI = 0.91-1.52, P = .22). Subgroup analysis revealed that a restrictive transfusion strategy was associated with a higher risk of in-hospital mortality (RR = 1.38, 95% CI = 1.15-1.67, P < .001) and 30 day mortality (RR = 1.21, 95% CI = 1.01-1.45, P = .03), compared with the liberal strategy. No significant difference was found between the liberal transfusion strategy and restrictive transfusion strategy in risk for subsequent myocardial infarction (RR = 1.09, 95% CI = 0.57-2.06, P = .80).

LIMITATIONS

Limitations include (1) limited number of trials, especially those evaluating myocardial infarction, (2) observed heterogeneity, (3) confounding by indication and other inherent bias may exist.

CONCLUSION

The findings suggest that restrictive blood transfusion was associated with higher in-hospital and 30 day mortality than liberal blood transfusion in CAD patients. The conclusions are mainly based on retrospective studies and should not be considered as recommendation before they are supported by randomized controlled trials.

The optimum hematocrit

The hematocrit (Hct) determines the oxygen carrying capacity of blood, but also increases blood viscosity and thus flow resistance. From this dual role the concept of an optimum Hct for tissue oxygenation has been derived. Viscometric studies using the ratio Hct/blood viscosity at high shear rate showed an optimum Hct of 50-60% for red blood cell (RBC) suspensions in plasma. For the perfusion of an artificial microvascular network with 5-70μm channels the optimum Hct was 60-70% for high driving pressures. With lower shear rates or driving pressures the optimum Hct shifted towards lower values. In healthy, well trained athletes an increase of the Hct to supra-normal levels can increase exercise performance. These data with healthy individuals suggest that the optimum Hct for oxygen transport may be higher than the physiological range (35-40% in women, 39-50% in men). This is in contrast to clinical observations. Large clinical studies have repeatedly shown that a correction of anemia in a variety of disorders such as chronic kidney disease, heart failure, coronary syndrome, oncology, acute gastrointestinal bleeding, critical care, or surgery have better clinical outcomes when restrictive transfusion strategies are applied. Actual guidelines, therefore, recommend a transfusion threshold of 7-8 g/dL hemoglobin (Hct 20-24%) in stable, hospitalized patients. The discrepancy between the optimum Hct in health and disease may be due to factors such as decreased perfusion pressures (low cardiac output, vascular stenoses, change in vascular tone), endothelial cell dysfunction, leukocyte adhesion and others.

Reducing liberal red blood cell transfusions at an academic medical center

BACKGROUND

Educational and computerized interventions have been shown to reduce red blood cell (RBC) transfusion rates, yet controversy remains surrounding the optimal strategy needed to achieve sustained reductions in liberal transfusions.

STUDY DESIGN AND METHODS

The purpose of this study was to assess the impact of clinician decision support (CDS) along with targeted education on liberal RBC utilization to four high-utilizing service lines compared with no education to control service lines across an academic medical center. Clinical data along with associated hemoglobin levels at the time of all transfusion orders between April 2014 and December 2015 were obtained via retrospective chart review. The primary outcome was the change in the rate of liberal RBC transfusion orders (defined as any RBC transfusion when the hemoglobin level is >7.0 g/dL). Secondary outcomes included the annual projected reduction in the number of transfusions and the associated decrease in cost due to these changes as well as length of stay (LOS) and death index. These measures were compared between the 12 months prior to the initiative and the 9-month postintervention period.

RESULTS

Liberal RBC utilization decreased from 13.4 to 10.0 units per 100 patient discharges (p = 0.002) across the institution, resulting in a projected 12-month savings of $720,360. The mean LOS and the death index did not differ significantly in the postintervention period.

CONCLUSION

Targeted education combined with the incorporation of CDS at the time of order entry resulted in significant reductions in the incidence of liberal RBC utilization without adversely impacting inpatient care, whereas control service lines exposed only to CDS had no change in transfusion habits.

Relationship Between Anemia and Mortality Outcomes in a National Acute Coronary Syndrome Cohort: Insights From the UK Myocardial Ischemia National Audit Project Registry

BACKGROUND

We aim to determine the prevalence of anemia in acute coronary syndrome (ACS) patients and compare their clinical characteristics, management, and clinical outcomes to those without anemia in an unselected national ACS cohort.

METHODS AND RESULTS

The Myocardial Ischemia National Audit Project (MINAP) registry collects data on all adults admitted to hospital trusts in England and Wales with diagnosis of an ACS. We conducted a retrospective cohort study by analyzing patients in this registry between January 2006 and December 2010 and followed them up until August 2011. Multiple logistic regressions were used to determine factors associated with anemia and the adjusted odds of 30-day mortality with 1 g/dL incremental hemoglobin increase and the 30-day and 1-year mortality for anemic compared to nonanemic groups. Analyses were adjusted for covariates. Our analysis of 422 855 patients with ACS showed that 27.7% of patients presenting with ACS are anemic and that these patients are older, have a greater prevalence of renal disease, peripheral vascular disease, diabetes mellitus, and previous acute myocardial infarction, and are less likely to receive evidence-based therapies shown to improve clinical outcomes. Finally, our analysis suggests that anemia is independently associated with 30-day (OR 1.28, 95% CI 1.22-1.35) and 1-year mortality (OR 1.31, 95% CI 1.27-1.35), and we observed a reverse J-shaped relationship between hemoglobin levels and mortality outcomes.

CONCLUSIONS

The prevalence of anemia in a contemporary national ACS cohort is clinically significant. Patients with anemia are older and multimorbid and less likely to receive evidence-based therapies shown to improve clinical outcomes, with the presence of anemia independently associated with mortality outcomes.

Transfusion thresholds and other strategies for guiding allogeneic red blood cell transfusion

BACKGROUND

There is considerable uncertainty regarding the optimal haemoglobin threshold for the use of red blood cell (RBC) transfusions in anaemic patients. Blood is a scarce resource, and in some countries, transfusions are less safe than others because of a lack of testing for viral pathogens. Therefore, reducing the number and volume of transfusions would benefit patients.

OBJECTIVES

The aim of this review was to compare 30-day mortality and other clinical outcomes in participants randomized to restrictive versus liberal red blood cell (RBC) transfusion thresholds (triggers) for all conditions. The restrictive transfusion threshold uses a lower haemoglobin level to trigger transfusion (most commonly 7 g/dL or 8 g/dL), and the liberal transfusion threshold uses a higher haemoglobin level to trigger transfusion (most commonly 9 g/dL to 10 g/dL).

SEARCH METHODS

We identified trials by searching CENTRAL (2016, Issue 4), MEDLINE (1946 to May 2016), Embase (1974 to May 2016), the Transfusion Evidence Library (1950 to May 2016), the Web of Science Conference Proceedings Citation Index (1990 to May 2016), and ongoing trial registries (27 May 2016). We also checked reference lists of other published reviews and relevant papers to identify any additional trials.

SELECTION CRITERIA

We included randomized trials where intervention groups were assigned on the basis of a clear transfusion 'trigger', described as a haemoglobin (Hb) or haematocrit (Hct) level below which a red blood cell (RBC) transfusion was to be administered.

DATA COLLECTION AND ANALYSIS

We pooled risk ratios of clinical outcomes across trials using a random-effects model. Two people extracted the data and assessed the risk of bias. We conducted predefined analyses by clinical subgroups. We defined participants randomly allocated to the lower transfusion threshold as 'restrictive transfusion' and to the higher transfusion threshold as 'liberal transfusion'.

MAIN RESULTS

A total of 31 trials, involving 12,587 participants, across a range of clinical specialities (e.g. surgery, critical care) met the eligibility criteria. The trial interventions were split fairly equally with regard to the haemoglobin concentration used to define the restrictive transfusion group. About half of them used a 7 g/dL threshold, and the other half used a restrictive transfusion threshold of 8 g/dL to 9 g/dL. The trials were generally at low risk of bias .Some items of methodological quality were unclear, including definitions and blinding for secondary outcomes.Restrictive transfusion strategies reduced the risk of receiving a RBC transfusion by 43% across a broad range of clinical specialties (risk ratio (RR) 0.57, 95% confidence interval (CI) 0.49 to 0.65; 12,587 participants, 31 trials; high-quality evidence), with a large amount of heterogeneity between trials (I² = 97%). Overall, restrictive transfusion strategies did not increase or decrease the risk of 30-day mortality compared with liberal transfusion strategies (RR 0.97, 95% CI 0.81 to 1.16, I² = 37%; N = 10,537; 23 trials; moderate-quality evidence) or any of the other outcomes assessed (i.e. cardiac events (low-quality evidence), myocardial infarction, stroke, thromboembolism (high-quality evidence)). Liberal transfusion did not affect the risk of infection (pneumonia, wound, or bacteraemia).

AUTHORS' CONCLUSIONS

Transfusing at a restrictive haemoglobin concentration of between 7 g/dL to 8 g/dL decreased the proportion of participants exposed to RBC transfusion by 43% across a broad range of clinical specialities. There was no evidence that a restrictive transfusion strategy impacts 30-day mortality or morbidity (i.e. mortality at other points, cardiac events, myocardial infarction, stroke, pneumonia, thromboembolism, infection) compared with a liberal transfusion strategy. There were insufficient data to inform the safety of transfusion policies in certain clinical subgroups, including acute coronary syndrome, myocardial infarction, neurological injury/traumatic brain injury, acute neurological disorders, stroke, thrombocytopenia, cancer, haematological malignancies, and bone marrow failure. The findings provide good evidence that transfusions with allogeneic RBCs can be avoided in most patients with haemoglobin thresholds above 7 g/dL to 8 g/dL.

Efficacy and Safety of Endovascular Therapy for Aortoiliac TASC D Lesions

Background:

Although there is increasing evidence of the effectiveness of endovascular therapy for complex aortoiliac (AI) occlusive disease, it is not universally applied to TASC D lesions.

Methods:

A total of 2096 patients, 2601 limbs with AI occlusive disease, were enrolled. The lesions were categorized as TASC D (395) or TASC A-C (2206), and we compared baseline data, procedure, and follow-up result between the 2 groups.

Results:

The success rate of the procedure was significantly lower in the TASC D group (91.6% vs 99.3%, P < .01), and more procedure complications occurred in the TASC D group (11.1% vs 5.2%, P < .01). The results of a 5-year follow-up revealed no significant difference in primary patency (77.9% vs 77.1%, P = .17) and major adverse cardiovascular and limb events (MACLE; 30.5% vs 33.4%, P = .42) between the 2 groups. A multivariate analysis revealed complications and critical limb ischemia are independent predictors of MACLE in the TASC D group.

Conclusion:

The success rate of the procedure was lower in the TASC D group. Complications were more frequent in the TASC D group, and they were related to MACLE.

Circulating Erythrocyte Microparticles and the Biochemical Extent of Myocardial Injury in ST Elevation Myocardial Infarction

Objectives: Red blood cell microparticles (RBCm) have potential adverse vascular effects and they have been shown to be elevated in ST elevation myocardial infarction (STEMI). The purpose of this study is to investigate their relationship with biochemical infarct size. Methods: RBCm were quantified with flow cytometry in blood drawn from 60 STEMI patients after a primary angioplasty. The creatine kinase-myocardial brain fraction (CK-MB) was measured at predefined time points and the area under the curve (AUC) was calculated. Results: RBCm count was correlated with CK-MB AUC (Spearman's ρ = 0.83, p < 0.001). The CK-MB AUC values per RBCm quartile (lower to upper) were: 3,351 (2,452-3,608), 5,005 (4,450-5,424), 5,903 (4,862-10,594), and 8,406 (6,848-12,782) ng × h/ml, respectively. From lower to upper quartiles, the maximal troponin I values were: 42.2 (23.3-49.3), 49.6 (28.8-54.1), 59.2 (41.4-77.3), and 69.1 (48.0-77.5) ng/ml (p = 0.005). In multivariable analysis, RBCm remained a significant predictor of CK-MB AUC (standardized β = 0.63, adjusted p = 0.001). Conclusions: Erythrocyte microparticles appear to be related to the total myocardial damage biomarker output. The exact pathophysiologic routes, if any, for this interaction remain to be identified. However, these results suggest that erythrocytes may be a - thus far virtually ignored - player in the pathogenesis of ischemic injury.

Red Blood Cell Transfusion in the Emergency Department

BACKGROUND

Transfusion of red blood cells (RBCs) is the primary management of anemia, which affects 90% of critically ill patients. Anemia has been associated with a poor prognosis in various settings, including critical illness. Recent literature has shown a hemoglobin transfusion threshold of 7 g/dL to be safe. This review examines several aspects of transfusion.

OBJECTIVE

We sought to provide emergency physicians with an updated review of indications for RBC transfusion in the emergency department.

DISCUSSION

The standard hemoglobin transfusion threshold was 10 g/dL. However, the body shows physiologic compensatory adaptations to chronic anemia. Transfusion reactions and infections are rare but can have significant morbidity and mortality. Products stored for <21 days have the lowest risk of reaction and infection. A restrictive threshold of 7 g/dL is recommended in the new American Association of Blood Banks guidelines and multiple meta-analyses and supported in gastrointestinal bleeding, sepsis, critical illness, and trauma. Patients with active ischemia in acute coronary syndrome and neurologic injury require additional study. The physician must consider the patient's hemodynamic status, comorbidities, risks and benefits of transfusion, and clinical setting in determining the need for transfusion.

CONCLUSIONS

RBC transfusion is not without risks, including transfusion reaction, infection, and potentially increased mortality. The age of transfusion products likely has no effect on products before 21 days of storage. A hemoglobin level of 7 g/dL is safe in the setting of critical illness, sepsis, gastrointestinal bleeding, and trauma. The clinician must evaluate and transfuse based on the clinical setting and patient hemodynamic status rather than using a specific threshold.

Transfusion practices and infectious risks

Transfusion-transmitted infections remain among the most-feared complications of allogeneic blood transfusion. Thanks to several strategies including donor screening and deferral, blood testing and pathogen inactivation, their risks have reached all-time low levels, particularly in developed nations. Nonetheless, new and emerging infections remain a threat that is likely to exacerbate in the coming years with continued globalization and climate change. More effective strategies of pathogen inactivation and more vigilant horizon screening are hoped to abate the risk. Additionally, allogeneic transfusion has repeatedly been shown to be associated with worsening of outcomes in patients, including the documented increased risk of infections (often nosocomial) in recipients of transfusions. The underlying mechanism is likely to be related to immunosuppressive effects of allogeneic blood, iron content, and bacterial contamination. This issue is best addressed by more judicious and evidence-based use of allogeneic blood components to ensure the potential benefits outweigh the risks.

Do orthopaedic trauma patients develop higher rates of cardiac complications? An analysis of 56,000 patients

PURPOSE

Less than 5 % of orthopaedic patients develop postoperative cardiac complications; however, there are little data suggesting which orthopaedic patients are at greatest risk. In an era where emerging reimbursement models place an emphasis on quality, reducing complications through perioperative planning will be of paramount importance for orthopaedic surgeons. The purpose of this study was to determine whether orthopaedic trauma patients are at greater risk for postoperative cardiac complications and to reveal which factors are most predictive of these complications.

METHODS

All orthopaedic patients were identified in the 2006-2013 ACS-NSQIP database. Cardiac complications were defined as cardiac arrests or myocardial infarctions within 30 days following surgery. Chi squared analysis determined differences in cardiac complication rates between trauma and non-trauma patients. Bivariate analysis incorporating over 40 patient/surgical characteristics determined significant associations between patient characteristics and cardiac complications. These factors were incorporated into a multivariate regression model to identify predictive risk factors for cardiac complications.

RESULTS

The presence of a traumatic injury resulted in greater odds of developing cardiac complications (OR: 1.645, p < 0.001). The cardiac complication rate in the trauma group was 1.3 % compared to 0.3 % in the non-trauma group (p < 0.001). For trauma patients, ventilator use (OR: 27.354, p = 0.004), recent transfusion (OR: 19.780, p = 0.001), and history of coma (OR: 17.922, p = 0.020) were most predictive of cardiac complications.

CONCLUSION

Orthopaedic trauma patients are more likely to develop cardiac complications than non-trauma patients. To reduce cardiac complications, orthopaedic traumatologists should be aware of patient risk factors including ventilator use, blood transfusion, and history of coma.

Bridging Anticoagulation: Primum Non Nocere

Chronic oral anticoagulation frequently requires interruption for various reasons and durations. Whether or not to bridge with heparin or other anticoagulants is a common clinical dilemma. The evidence to inform decision making is limited, making current guidelines equivocal and imprecise. Moreover, indications for anticoagulation interruption may be unclear. New observational studies and a recent large randomized trial have noted significant perioperative or periprocedural bleeding rates without reduction in thromboembolism when bridging is employed. Such bleeding may also increase morbidity and mortality. In light of these findings, physician preferences for routine bridging anticoagulation during chronic anticoagulation interruptions may be too aggressive. More randomized trials, such as PERIOP2 (A Double Blind Randomized Control Trial of Post-Operative Low Molecular Weight Heparin Bridging Therapy Versus Placebo Bridging Therapy for Patients Who Are at High Risk for Arterial Thromboembolism), will help guide periprocedural management of anticoagulation for indications such as venous thromboembolism and mechanical heart valves. In the meantime, physicians should carefully consider both the need for oral anticoagulation interruption and the practice of routine bridging when anticoagulation interruption is indicated.