The accuracy of natriuretic peptides (brain natriuretic peptide and N-terminal pro-brain natriuretic) in the differentiation between transfusion-related acute lung injury and transfusion-related circulatory overload in the critically ill

Comparison of cardiac biomarkers on risk assessment of contrast-associated acute kidney injury in patients undergoing cardiac catheterization: A multicenter retrospective study

AIM

Cardiac biomarkers' predictive value of contrast-associated acute kidney injury (CA-AKI) remains unclear. We analysed whether creatine kinase isoenzyme-MB (CKMB), cardiac troponin I (cTnI) and preoperative N-terminal pro-brain natriuretic peptide (NT-proBNP) are tied to CA-AKI patients undergoing cardiac catheterization.

METHODS

In the multi-center study, we included 3553 people underwent cardiac catheterization for analysis. CA-AKI was defined as the absolute increase of over 0.3 mg/dL or an increase of more than 50% compared with the baseline serum creatinine within 48 hours following cardiac catheterization. Logistic regression model and receiver operating characteristic (ROC) curves were used to examine the association between cardiac biomarkers and CA-AKI and the efficacy of Mehran risk score (MRS) model on CA-AKI prediction with and without cardiac biomarkers.

RESULTS

Among 3553 people, 200 people eventually developed CA-AKI. The logistic regression model showed that log10 CKMB (odds ratio (OR): 1.97, 95%CI:1.51-2.57, p < .001), cTnI (OR: 1.03, 95%CI: 1.02-1.04, p < .001) and log10 NT-proBNP (OR: 3.19, 95%CI: 2.46-4.17, p < .001) were independent predictors of CA-AKI. The ROC curve demonstrated that area under the curve (AUC) of MRS was 0.733. CKMB, cTnI and NT-proBNP all significantly improved the AUC value in combination with MRS model. (NT-proBNP: 0.798, p < .001; CKMB: 0.758, p = .003; cTnI: 0.755, p = .002), among which the NT-proBNP had the best predictive efficacy improvement.

CONCLUSION

Cardiac biomarkers of CKMB, cTnI and NT-proBNP are all independently associated with CA-AKI among patients undergoing cardiac catheterization while NT-proBNP remains the best indicator. Adding CKMB, cTnI and NT-proBNP to MRS improved the prognostic efficacy and may be considered effective tools to predict the risk of CA-AKI in clinical practice.

Exploring NT-proBNP, syndecan-1, and cytokines as biomarkers for transfusion-associated circulatory overload in a critically ill patient population receiving a single-unit red blood cell transfusion

BACKGROUND

Transfusion-associated circulatory overload (TACO) is an often underdiagnosed pulmonary transfusion complication. A biomarker could aid with the diagnosis. To date, B-type natriuretic peptide (BNP) and N-terminal prohormone B-type natriuretic peptide (NT-proBNP) seem the most promising biomarkers in the general hospital population. The aim was to evaluate NT-proBNP as a biomarker for TACO in a critically ill patient population and explore syndecan-1 and cytokines as other potential biomarkers.

STUDY DESIGN AND METHODS

A retrospective study was performed using samples and clinical data collected during a prospective observational study. Adult patients admitted to the intensive care and transfused with a single red blood cell unit were included. TACO cases were retrospectively identified using a case definition based on the current TACO definition. The primary biomarker was NT-proBNP, also we measured syndecan-1 IL-6, IL-8, and IL-10. All markers were measured directly before transfusion, 1 and 24 h after transfusion.

RESULTS

Our cohort included 64 patients, 12 of which were identified as TACO patients. TACO patients had a lower PaO2 /FiO2 ratio and were more often ventilated following transfusion compared to non-TACO patients. There was no significant difference in NT-proBNP between pre- and post-transfusion levels nor between TACO and non-TACO patients. Syndecan-1 was significantly elevated in TACO patients both pre- and post-transfusion compared to non-TACO patients.

DISCUSSION

NT-proBNP was not associated with TACO in this critically ill patient population. Interestingly, levels of syndecan-1 were increased in TACO patients at baseline. More research is needed to clarify this association and its possibilities as a biomarker to predict patients at risk for TACO.

Rasburicase-induced hemolytic anemia and methemoglobinemia: a systematic review of current reports

Since the FDA's approval of rasburicase use for treatment of tumor lysis syndrome (TLS), multiple cases of rasburicase-induced methemoglobinemia and hemolytic anemia have been reported among patients with G6PD deficiency. This study aims to provide a systematic review of cases reporting such adverse reactions to rasburicase. A literature review of published cases in PubMed, Embase, Cochrane, and Web of Science was conducted. Descriptive studies reporting cases of rasburicase-induced methemoglobinemia and/or hemolytic anemia in English were analyzed and summarized in this study. Forty-three cases, including a case from our institution, were included in this study. Most cases (60.5%) received rasburicase for TLS treatment. Almost all patients (93.8%) were tested for G6PD after rasburicase administration. The median time to symptom onset was 24 h. The median methemoglobin level was 10%, peaking after a median of 24 h. The median hemoglobin nadir was 6.1 g/dL, and most patients (n = 32) required blood transfusion. Out of 39 cases with reported outcomes, 35 patients (89.7%) recovered, while four patients (three females and one male) died. The median time to recovery was 4.5 days while the median time to death was 8 days. Screening for G6PD deficiency among high-risk patients is important but not practical in acutely severe settings. When prior screening for G6PD deficiency is not feasible, close monitoring for methemoglobinemia and hemolytic anemia is recommended. Exchange transfusion is increasingly reported as a potentially successful therapeutic modality. Ascorbic acid may provide limited benefits. Methylene blue should be avoided as it may exacerbate hemolysis among these patients.

The recipe for TACO: A narrative review on the pathophysiology and potential mitigation strategies of transfusion-associated circulatory overload

Transfusion associated circulatory overload (TACO) is one of the leading causes of transfusion related morbidity and mortality. TACO is the result of hydrostatic pulmonary edema following transfusion. However, up to 50% of all TACO cases appear after transfusion of a single unit, suggesting other factors, aside from volume, play a role in its pathophysiology. TACO follows a two-hit model, in which the first hit is an existing disease or comorbidity that renders patients volume incompliant, and the second hit is the transfusion. First hit factors include, amongst others, cardiac and renal failure. Blood product factors, setting TACO apart from crystalloid overload, include colloid osmotic pressure effects, viscosity, pro-inflammatory mediators and storage lesion byproducts. Differing hemodynamic changes, glycocalyx injury, endothelial damage and inflammatory reactions can all contribute to developing TACO. This narrative review explores pathophysiological mechanisms for TACO, discusses related therapeutic and preventative measures, and identifies areas of interest for future research.

Transfusion-Associated Circulatory Overload and Transfusion-Related Acute Lung Injury

OBJECTIVES

To review the new current diagnostic criteria of transfusion-associated circulatory overload (TACO) and transfusion-related acute lung injury (TRALI) from the literature while highlighting distinguishing features. We provide comprehensive understanding of the importance of hemovigilance and its role in appropriately identifying and reporting these potentially fatal transfusion reactions.

METHODS

A review of the English language literature was performed to analyze TACO and TRALI while providing further understanding of the rationale behind the historical underrecognition and underreporting.

RESULTS

Our review demonstrates the new 2018 and 2019 case definitions for TACO and TRALI, respectively. With more comprehensive diagnostic strategies, adverse transfusion events can be better recognized from mimicking events and underlying disease. In addition, there are mitigation strategies in place to help prevent complications of blood product transfusion, with emphasis on the prevention of TACO and TRALI.

CONCLUSIONS

TACO and TRALI are potentially fatal adverse complications of blood transfusion. Both have been historically underrecognized and underreported due to poor defining criteria and overlapping symptomatology. Developing a thorough clinical understanding between these two entities can improve hemovigilance reporting and can contribute to risk factor identification and preventative measures.

Association of Veterinary Hematology and Transfusion Medicine (AVHTM) transfusion reaction small animal consensus statement (TRACS). Part 3: Diagnosis and treatment

OBJECTIVE

To systematically review available evidence to develop guidelines for diagnosis and treatment of transfusion-associated reactions in dogs and cats.

DESIGN

Standardized and systemic evaluation of the literature (identified through Medline via PubMed and Google Scholar searches) was carried out for identified transfusion reaction types in dogs and cats. The available evidence was evaluated using PICO (Population, Intervention, Comparison, Outcome) questions generated for each reaction type. The evidence was categorized by level of evidence (LOE) and quality (Good, Fair, or Poor). Guidelines, diagnostic, and treatment algorithms were generated based on the evaluation of the evidence. Consensus on the final guidelines was achieved through Delphi-style surveys. Draft recommendations were disseminated through veterinary specialty listservs for review and comments, which were evaluated and integrated prior to final publication.

RESULTS

Medline via PubMed and Google Scholar databases were searched. There were 14 Population Intervention Comparison Outcome questions identified and corresponding worksheets were developed focusing on the diagnosis and treatment of transfusion-associated reactions in dogs and cats. Fourteen guidelines and four algorithms were developed with a high degree of consensus.

CONCLUSIONS

This systematic evidence evaluation process yielded recommended diagnostic and treatment algorithms for use in practice. However, significant knowledge gaps were identified, demonstrating the need for additional research in veterinary transfusion medicine.

Transfusion-associated circulatory overload and high blood pressure: A multicentre retrospective study in Japan

BACKGROUND

Transfusion-associated circulatory overload (TACO) is an adverse reaction associated with a high risk of mortality. The actual incidence of TACO and hypertension associated with transfusion in Japan is unknown.

METHODS

A multicentre retrospective observational study was conducted across 23 institutions during the 1-year period of 2016. Patients were included if they developed TACO or their blood pressure (either systolic or diastolic) increased by at least 30 mmHg during the transfusion. TACO was confirmed by the primary physicians and transfusion medicine teams and recorded in the data on passive surveillance, and additional data were extracted from electronic medical records.

RESULTS

In our patient cohort of 31 384 patients who underwent transfusion, the incidence of TACO and hypertension was 0·03% and 0·2%, respectively. However, 43% of the participating institutions didn't report any cases. When comparing risk factors between the TACO and hypertension groups, there were significant differences in comorbidities, such as abnormal findings on chest x-ray. Significant differences between the two groups were observed post-transfusion pulse rate, body temperature and oxygen saturation (P < 0·01). In the group of patients with hypertension, the level of BNP increased significantly after transfusion in 45% (5/11) of the patients. We identified 4 patients in the hypertension group who met the new ISBT's TACO criteria.

CONCLUSION

Our study suggests that more attention should be given to TACO in Japan, particularly in terms of improving surveillance systems. For the early diagnosis of TACO, it is crucial to carefully monitor vital signs including blood pressure.

Pulmonary complications of transfusion: Changes, challenges, and future directions

The pulmonary complications of transfusion (TACO, TRALI and TAD) are the leading cause of transfusion-related mortality and major morbidity. Advance in this area is essential in improving transfusion safety. This review describes the drivers for change in haemovigilance practice, the influence of recent key publications and future directions.

NT-proBNP levels in the identification and classification of pulmonary transfusion reactions

BACKGROUND

Consensus definitions for transfusion-related acute lung injury (TRALI) and transfusion-associated circulatory overload (TACO) have recently been revised; however, pulmonary transfusion reactions remain difficult to diagnose. We hypothesized that N-terminal pro-brain natriuretic peptide (NT-proBNP) levels could have utility in the identification and classification of pulmonary transfusion reactions.

STUDY DESIGN AND METHODS

We performed a secondary analysis of a case-control study of pulmonary transfusion reactions at four academic hospitals. We evaluated clinical data and measured NT-proBNP levels prior to and following transfusion in patients with TACO (n = 160), transfused acute respiratory distress syndrome (ARDS) [n = 51], TRALI [n = 12], TACO/TRALI [n = 7], and controls [n = 335]. We used Wilcoxon Rank-Sum tests to compare NT-proBNP levels, and classification and regression tree (CART) algorithms to produce a ranking of covariates in order of relative importance for differentiating TACO from transfused controls.

RESULTS

Pre-transfusion NT-proBNP levels were elevated in cases of transfused ARDS and TACO (both P < .001) but not TRALI (P = .31) or TACO/TRALI (P = .23) compared to transfused controls. Pre-transfusion NT-proBNP levels were higher in cases of transfused ARDS or TRALI with a diagnosis of sepsis compared to those without (P < .05 for both). CART analyses resulted in similar differentiation of patients with TACO from transfused controls for models utilizing either NT-proBNP levels (AUC 0.83) or echocardiogram results (AUC 0.80).

CONCLUSIONS

NT-proBNP levels may have utility in the classification of pulmonary transfusion reactions. Prospective studies are needed to test the predictive utility of pre-transfusion NT-proBNP in conjunction with other clinical factors in identifying patients at risk of pulmonary transfusion reactions.

Contemporary Risk Factors and Outcomes of Transfusion-Associated Circulatory Overload

OBJECTIVES

Transfusion-associated circulatory overload is characterized by hydrostatic pulmonary edema following blood transfusion. Restrictive transfusion practice may affect the occurrence and severity of transfusion-associated circulatory overload in critically ill patients. We sought to examine contemporary risk factors and outcomes for transfusion-associated circulatory overload.

DESIGN

Case-control study.

SETTING

Four tertiary care hospitals.

PATIENTS

We prospectively enrolled 200 patients with transfusion-associated circulatory overload identified by active surveillance and 405 controls matched by transfusion intensity.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Among 20,845 transfused patients who received 128,263 blood components from May 2015 until July 2016, transfusion-associated circulatory overload incidence was one case per 100 transfused patients. In addition to cardiovascular comorbidities, multivariable analysis identified the following independent predictors of transfusion-associated circulatory overload: acute kidney injury, emergency surgery, pretransfusion diuretic use, and plasma transfusion-the latter especially in females. Compared with matched controls, transfusion-associated circulatory overload cases were more likely to require mechanical ventilation (71% vs 49%; p < 0.001), experienced longer intensive care and hospital lengths of stay following transfusion, and had higher mortality (21% vs 11%; p = 0.02) even after adjustment for other potentially confounding variables.

CONCLUSIONS

Despite restrictive transfusion practice, transfusion-associated circulatory overload remains a frequent complication of transfusion and is an independent risk factor for in-hospital morbidity and mortality. In addition to cardiovascular and renal risk factors, plasma transfusion was associated with transfusion-associated circulatory overload after controlling for other covariates. Additional research is needed to examine the benefit of reduced erythrocyte or plasma exposure in patients at high risk for transfusion-associated circulatory overload.

Transfusion-related Acute Lung Injury in the Perioperative Patient

Transfusion-related acute lung injury is a leading cause of death associated with the use of blood products. Transfusion-related acute lung injury is a diagnosis of exclusion which can be difficult to identify during surgery amid the various physiologic and pathophysiologic changes associated with the perioperative period. As anesthesiologists supervise delivery of a large portion of inpatient prescribed blood products, and since the incidence of transfusion-related acute lung injury in the perioperative patient is higher than in nonsurgical patients, anesthesiologists need to consider transfusion-related acute lung injury in the perioperative setting, identify at-risk patients, recognize early signs of transfusion-related acute lung injury, and have established strategies for its prevention and treatment.

A consensus redefinition of transfusion-related acute lung injury

BACKGROUND

Transfusion-related acute lung injury (TRALI) is a serious complication of blood transfusion and is among the leading causes of transfusion-related morbidity and mortality in most developed countries. In the past decade, the pathophysiology of this potentially life-threatening syndrome has been increasingly elucidated, large cohort studies have identified associated patient conditions and transfusion risk factors, and preventive strategies have been successfully implemented. These new insights provide a rationale for updating the 2004 consensus definition of TRALI.

STUDY DESIGN AND METHODS

An international expert panel used the Delphi methodology to develop a redefinition of TRALI by modifying and updating the 2004 definition. Additionally, the panel reviewed issues related to TRALI nomenclature, patient conditions associated with acute respiratory distress syndrome (ARDS) and TRALI, TRALI pathophysiology, and standardization of reporting of TRALI cases.

RESULTS

In the redefinition, the term "possible TRALI" has been dropped. The terminology of TRALI Type I (without an ARDS risk factor) and TRALI Type II (with an ARDS risk factor or with mild existing ARDS) is proposed. Cases with an ARDS risk factor that meet ARDS diagnostic criteria and where respiratory deterioration over the 12 hours before transfusion implicates the risk factor as causative should be classified as ARDS. TRALI remains a clinical diagnosis and does not require detection of cognate white blood cell antibodies.

CONCLUSIONS

Clinicians should report all cases of posttransfusion pulmonary edema to the transfusion service so that further investigation can allow for classification of such cases as TRALI (Type I or Type II), ARDS, transfusion-associated circulatory overload (TACO), or TRALI or TACO cannot distinguish or an alternate diagnosis.

Transfusion-associated circulatory overload and transfusion-related acute lung injury

Transfusion-associated circulatory overload (TACO) and transfusion-related acute lung injury (TRALI) are syndromes of acute respiratory distress that occur within 6 hours of blood transfusion. TACO and TRALI are the leading causes of transfusion-related fatalities, and specific therapies are unavailable. Diagnostically, it remains very challenging to distinguish TACO and TRALI from underlying causes of lung injury and/or fluid overload as well as from each other. TACO is characterized by pulmonary hydrostatic (cardiogenic) edema, whereas TRALI presents as pulmonary permeability edema (noncardiogenic). The pathophysiology of both syndromes is complex and incompletely understood. A 2-hit model is generally assumed to underlie TACO and TRALI disease pathology, where the first hit represents the clinical condition of the patient and the second hit is conveyed by the transfusion product. In TACO, cardiac or renal impairment and positive fluid balance appear first hits, whereas suboptimal fluid management or other components in the transfused product may enable the second hit. Remarkably, other factors beyond volume play a role in TACO. In TRALI, the first hit can, for example, be represented by inflammation, whereas the second hit is assumed to be caused by antileukocyte antibodies or biological response modifiers (eg, lipids). In this review, we provide an up-to-date overview of TACO and TRALI regarding clinical definitions, diagnostic strategies, pathophysiological mechanisms, and potential therapies. More research is required to better understand TACO and TRALI pathophysiology, and more biomarker studies are warranted. Collectively, this may result in improved diagnostics and development of therapeutic approaches for these life-threatening transfusion reactions.

Cardiac stress biomarkers after red blood cell transfusion in patients at risk for transfusion-associated circulatory overload: a prospective observational study

BACKGROUND

Transfusion-associated circulatory overload (TACO) is a leading cause of serious reactions. In regard to TACO, little is known regarding biomarkers as a predictor, their most informative timing, or thresholds of significance or differentiation from other reactions.

STUDY DESIGN AND METHODS

In this study of inpatients at risk for TACO (age ≥ 50 years) receiving 1 red blood cell unit, cardiac biomarkers, brain natriuretic peptide (BNP), N-terminal pro-BNP (NT-proBNP), and high-sensitivity troponin were measured at baseline, 6 to 12 hours (except troponin) posttransfusion, and 18 to 24 hours posttransfusion. Primary outcome was a critical increase in biomarkers (>1.5-fold increase and supranormal) at 18 to 24 hours.

RESULTS

Fifty-one patients were analyzed; 29% had cardiovascular disease, 73% had one or more cardiac risk factors, and 50% took cardiac or antihypertensive therapies. Although eight (16%) developed an increase in systolic pressure of at least 30 mmHg and four (8%) reported dyspnea and/or cough, none had TACO. At baseline, BNP level was more than 100 ng/L in 59% and NT-proBNP was more than 300 pg/mL in 83%. A total of 25% had a BNP critical increase, 33% had a NT-proBNP critical increase, and 2% had a troponin critical increase at 18 to 24 hours. Overall, 38% had at least one biomarker critical increase and NT-proBNP/BNP concordance was 84%. An increase in the NT-proBNP (>1.5-fold increase and >300 pg/mL) at 18 to 24 hours was the commonest biomarker change.

CONCLUSIONS

An increase of the NT-proBNP at 18 to 24 hours may be the preferred surrogate marker for identifying a patient experiencing physiologic difficulty in handling the volume challenge. Larger studies are needed to clarify the risk of TACO for a given pretransfusion biomarker profile and the correlation between TACO and increase in biomarkers after transfusion.

TACO and TRALI: biology, risk factors, and prevention strategies

Transfusion-related acute lung injury (TRALI) and transfusion-associated circulatory overload (TACO) are the leading causes of transfusion-related morbidity and mortality. These adverse events are characterized by acute pulmonary edema within 6 hours of a blood transfusion and have historically been difficult to study due to underrecognition and nonspecific diagnostic criteria. However, in the past decade, in vivo models and clinical studies utilizing active surveillance have advanced our understanding of their epidemiology and pathogenesis. With the adoption of mitigation strategies and patient blood management, the incidence of TRALI and TACO has decreased. Continued research to prevent and treat these severe cardiopulmonary events is focused on both the blood component and the transfusion recipient.

Transfusion-associated circulatory overload-a systematic review of diagnostic biomarkers

BACKGROUND

Transfusion‐associated circulatory overload (TACO) is the leading cause of transfusion‐related major morbidity and mortality. Diagnosing TACO is difficult because there are no pathognomonic signs and symptoms. TACO biomarkers may aid in diagnosis, decrease time to treatment, and differentiate from other causes of posttransfusion dyspnea such a transfusion‐related acute lung injury.

STUDY DESIGN AND METHODS

A systematic review of literature was performed in EMBASE, PubMed, the TRIP Database, and the Cochrane Library, from inception to June 2018. All articles discussing diagnostic markers for TACO were included. Non‐English articles or conference abstracts were excluded.

RESULTS

Twenty articles discussing biomarkers for TACO were included. The majority investigated B‐type natriuretic peptide (BNP) and the N‐terminal prohormone cleavage fragment of BNP (NT‐proBNP), markers of hydrostatic pressure that can be determined within 1 hour. The data indicate that a post/pretransfusion NT‐proBNP ratio > 1.5 can aid in the diagnosis of TACO. Posttransfusion levels of BNP less than 300 or NT‐proBNP less than 2000 pg/mL, drawn within 24 hours of the reaction, make TACO unlikely. Cut‐off levels that exclude TACO are currently unclear. In critically ill patients, the specificity of natriuretic peptides for circulatory overload is poor. Other biomarkers, such as cytokine profiles, cannot discriminate between TACO and transfusion‐related acute lung injury.

CONCLUSION

Currently, BNP and NT‐proBNP are the primary diagnostic biomarkers researched for TACO. An NT‐proBNP ratio greater than 1.5 is supportive of TACO, and low levels of BNP or NT‐proBNP can exclude TACO. However, they are unreliable in critically ill patients. Other biomarkers, including cytokines and pulmonary edema fluid‐to‐serum protein ratio have not yet been sufficiently investigated for clinical use.

Short-term outcome of cardiac surgery under cardiopulmonary bypass in patients who refuse transfusion: a controlled study

BACKGROUND

Although bloodless cardiac surgery has been successfully performed for many years, studies with controls permitting transfusion are few and their results inconclusive. This study compares the outcome of cardiac surgery on Jehovah's Witnesses (JW) refusing transfusion, with that of controls permitting transfusion if required.

METHODS

Data from 172 operations in 162 JW were compared with 172 matched controls. Risk factors, preoperative, operative, 48 hour postoperative variables, outcome data and transfusions were recorded.

RESULTS

Preoperative and operative variables were similar in both groups except for more previous cardiac operations, and more frequent use of cell saver and aprotinin in JW, who bled less and had higher hemoglobin concentrations at all periods. Thirty-day mortality was higher in JW (9.9% vs. 3.5%; P=0.03) (Risk difference 6.4%; CI95%: 2.7-10.1). Nevertheless operative mortality was similar in both groups (9.9% vs. 7.6%; P=0.44). Mortality in low-risk subjects was higher in JW (8.9% vs. 1.0%; P=0.02) (Risk difference 7.9%; CI95%: 2.7-13.2). Moreover, death associated with hemorrhage and anemia tended to be more frequent in JW. Mortality of transfused controls (14.1%) and their matched JW (13.0%) was similar. In contrast, mortality of non-transfused controls was zero versus 6.3% in their matched JW (P=0.059).

CONCLUSIONS

Low-risk JW had significantly higher mortality than controls. Bleeding related deaths tended to be more frequent in JW. Blood-sparing maneuvers should be intensively implemented in both JW and patients permitting transfusion in order to reduce bleeding and the need for transfusion with its harmful effects.

Point-of-care washing of allogeneic red blood cells for the prevention of transfusion-related respiratory complications (WAR-PRC): a protocol for a multicenter randomised clinical trial in patients undergoing cardiac surgery

INTRODUCTION

The transfusion-related respiratory complications, transfusion-related acute lung injury (TRALI) and transfusion-associated circulatory overload (TACO), are leading causes of transfusion-related morbidity and mortality. At present, there are no effective preventive strategies with red blood cell (RBC) transfusion. Although mechanisms remain incompletely defined, soluble biological response modifiers (BRMs) within the RBC storage solution may play an important role. Point-of-care (POC) washing of allogeneic RBCs may remove these BRMs, thereby mitigating their impact on post-transfusion respiratory complications.

METHODS AND ANALYSIS

This is a multicenter randomised clinical trial of standard allogeneic versus washed allogeneic RBC transfusion for adult patients undergoing cardiac surgery testing the hypothesis that POC RBC washing is feasible, safe, and efficacious and will reduce recipient immune and physiologic responses associated with transfusion-related respiratory complications. Relevant clinical outcomes will also be assessed. This investigation will enrol 170 patients at two hospitals in the USA. Simon's two-stage design will be used to assess the feasibility of POC RBC washing. The primary safety outcomes will be assessed using Wilcoxon Rank-Sum tests for continuous variables and Pearson chi-square test for categorical variables. Standard mixed modelling practices will be employed to test for changes in biomarkers of lung injury following transfusion. Linear regression will assess relationships between randomised group and post-transfusion physiologic measures.

ETHICS AND DISSEMINATION

Safety oversight will be conducted under the direction of an independent Data and Safety Monitoring Board (DSMB). Approval of the protocol was obtained by the DSMB as well as the institutional review boards at each institution prior to enrolling the first study participant. This study aims to provide important information regarding the feasibility of POC washing of allogeneic RBCs and its potential impact on ameliorating post-transfusion respiratory complications. Additionally, it will inform the feasibility and scientific merit of pursuing a more definitive phase II/III clinical trial.

REGISTRATION

ClinicalTrials.gov registration number is NCT02094118 (Pre-results).

Transfusion Reactions

Transfusion reactions are common occurrences, and clinicians who order or transfuse blood components need to be able to recognize adverse sequelae of transfusion. The differential diagnosis of any untoward clinical event should always consider adverse sequelae of transfusion, even when transfusion occurred weeks earlier. There is no pathognomonic sign or symptom that differentiates a transfusion reaction from other potential medical problems, so vigilance is required during and after transfusion when a patient presents with a change in clinical status. This review covers the presentation, mechanisms, and management of transfusion reactions that are commonly encountered, and those that can be life-threatening.

Transfusion-associated circulatory overload in a pediatric patient with neuroblastoma

There have been few reports on pediatric transfusion-associated circulatory overload (TACO). A 5-year-old boy with neuroblastoma underwent resection of the residual tumor. Because anemia progressed at the end of the operation, transfusion of red cell component was initiated. Ten minutes later, he suddenly developed hypoxemia, tachypnea, and tachycardia. Although elevated blood pressure and bilateral infiltrative shadows on chest X-rays were not observed, TACO was diagnosed based on positive balance during operation and N-terminal pro-brain natriuretic peptide elevation. He had no cardiac or renal disorder; however, mild cardiac and/or renal damage due to a long history of chemotherapy and bias toward his primary hematological and malignant disease may have affected the development of TACO.

Differentiating pulmonary transfusion reactions using recipient and transfusion factors

BACKGROUND

It is increasingly recognized that recipient risk factors play a prominent role in possible transfusion-related acute lung injury (pTRALI) and transfusion-associated circulatory overload (TACO). We hypothesized that both transfusion and recipient factors including natriuretic peptides could be used to distinguish TRALI from TACO and pTRALI.

STUDY DESIGN AND METHODS

We performed a post hoc analysis of a case-control study of pulmonary transfusion reactions conducted at the University of California at San Francisco and Mayo Clinic, Rochester. We evaluated clinical data and brain natriuretic peptides (BNP) levels drawn after transfusion in patients with TRALI (n = 21), pTRALI (n = 26), TACO (n = 22), and controls (n = 24). Logistic regression and receiver operating characteristics curve analyses were used to determine the accuracy of clinical and biomarker predictors in differentiating TRALI from TACO and pTRALI.

RESULTS

We found that pTRALI and TACO were associated with older age, higher fluid balance, and elevated BNP levels relative to those of controls and TRALI. The following variables were useful in distinguishing cases of pTRALI and TACO from TRALI: age more than 70 years, BNP levels more than 1000 pg/mL, 24-hour fluid balance of more than 3 L, and a lower number of transfused blood components. Using the above variables, our logistic model had a 91% negative predictive value in the differential diagnosis of TRALI.

CONCLUSIONS

Models incorporating readily available clinical and biomarker data can be used to differentiate transfusion-related respiratory complications. Additional studies examining recipient risk factors and the likelihood of TRALI may be useful in decision making regarding donor white blood cell antibody testing.

Incidence and clinical characteristics of transfusion-associated circulatory overload using an active surveillance algorithm

BACKGROUND

The concordance of haemovigilance criteria developed for surveillance of transfusion-associated circulatory overload (TACO) with its clinical diagnosis has not been assessed. In a pilot study to evaluate an electronic screening algorithm, we sought to examine TACO incidence and application of haemovigilance criteria in patients with post-transfusion pulmonary oedema.

STUDY DESIGN AND METHODS

From June to September 2014, all transfused adult inpatients at four academic hospitals were screened with an algorithm identifying chest radiographs ordered within 12 h of blood component release. Patients with post-transfusion pulmonary oedema underwent case adjudication by an expert panel. TACO incidence was calculated, and clinical characteristics were compared with other causes of post-transfusion pulmonary oedema.

RESULTS

Among 4932 transfused patients, there were 3412 algorithm alerts, 50 cases of TACO and 47 other causes of pulmonary oedema. TACO incidence was 1 case per 100 patients transfused. TACO classification based on two sets of haemovigilance criteria (National Healthcare Safety Network and proposed revised International Society for Blood Transfusion) was concordant with expert panel diagnosis in 57% and 54% of reviewed cases, respectively. Although the majority of clinical parameters did not differentiate expert panel adjudicated TACO from other cases, improved oxygenation within 24 h of transfusion did (P = 0·01).

CONCLUSIONS

The incidence of TACO was similar to that observed in prior studies utilizing active surveillance. Case classification by haemovigilance criteria was frequently discordant with clinical diagnoses of TACO in patients with post-transfusion pulmonary oedema. Improvements in oxygenation within 24 h of transfusion merit further evaluation in the diagnosis of TACO.

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.

B-Type Natriuretic Peptide, Aldosterone, and Fluid Management in ARDS

BACKGROUND

Conservative fluid management increases ventilator-free days without influencing overall mortality in acute respiratory distress syndrome. Plasma concentrations of B-type natriuretic peptide (a marker of ventricular filling) or aldosterone (a marker of effective circulating volume) may identify patients for whom fluid management impacts survival.

METHODS

This was a retrospective analysis of the Fluid and Catheter Treatment Trial (FACTT), a randomized trial comparing conservative with liberal fluid management in acute respiratory distress syndrome. Using plasma collected at study enrollment, we measured B-type natriuretic peptide and aldosterone by immunoassay. Multivariable analyses examined the interaction between B-type natriuretic peptide or aldosterone concentration and fluid strategy with regard to 60-day in-hospital mortality.

RESULTS

Among 625 patients with adequate plasma, median B-type natriuretic peptide concentration was 825 pg/mL (interquartile range, 144-1,574 pg/mL), and median aldosterone was 2.49 ng/dL (interquartile range, 1.1-4.3 ng/dL). B-type natriuretic peptide did not predict overall mortality, correlate with fluid balance, or modify the effect of conservative vs liberal fluid management on outcomes. In contrast, among patients with lower aldosterone concentrations, conservative fluid management increased ventilator-free days (17.1 ± 9.8 vs 12.5 ± 10.3, P < .001) and decreased mortality (19% vs 30%, P = .03) (P value for interaction = .01).

CONCLUSIONS

In acute respiratory distress syndrome, B-type natriuretic peptide does not modify the effect of fluid management on outcomes. Lower initial aldosterone appears to identify patients for whom conservative fluid management may improve mortality.

Cytokines and clinical predictors in distinguishing pulmonary transfusion reactions

BACKGROUND

Pulmonary transfusion reactions are important complications of blood transfusion, yet differentiating these clinical syndromes is diagnostically challenging. We hypothesized that biologic markers of inflammation could be used in conjunction with clinical predictors to distinguish transfusion-related acute lung injury (TRALI), transfusion-associated circulatory overload (TACO), and possible TRALI.

STUDY DESIGN AND METHODS

In a nested case-control study performed at the University of California at San Francisco and Mayo Clinic, Rochester, we evaluated clinical data and blood samples drawn before and after transfusion in patients with TRALI (n = 70), possible TRALI (n = 48), TACO (n = 29), and controls (n = 147). Cytokines measured included granulocyte-macrophage-colony-stimulating factor, interleukin (IL)-6, IL-8, IL-10, and tumor necrosis factor-α. Logistic regression and receiver operating characteristics curve analyses were used to determine the accuracy of clinical predictors and laboratory markers in differentiating TACO, TRALI, and possible TRALI.

RESULTS

Before and after transfusion, IL-6 and IL-8 were elevated in patients with TRALI and possible TRALI relative to controls, and IL-10 was elevated in patients with TACO and possible TRALI relative to that of TRALI and controls. For all pulmonary transfusion reactions, the combination of clinical variables and cytokine measurements displayed optimal diagnostic performance, and the model comparing TACO and TRALI correctly classified 92% of cases relative to expert panel diagnoses.

CONCLUSIONS

Before transfusion, there is evidence of systemic inflammation in patients who develop TRALI and possible TRALI but not TACO. A predictive model incorporating readily available clinical and cytokine data effectively differentiated transfusion-related respiratory complications such as TRALI and TACO.

Split Blood Products

The last 20 years have seen many advances in transfusion therapy and safety. Blood products are biological products engendering complex interactions with the immune system. Prestorage leukoreduction results in a reduced risk of febrile reactions, CMV transmission, and immune modulation, proving to be safer for patients than non-leuko reduced products.

Simple patient identification issues and clerical error continue to be the primary causes of ABO-incompatible transfusions. Rigorous donor screening as well as serologic and nucleic acid testing for transfusion transmitted infection have brought the blood supply to a very safe level, although transmission of these agents continues to be a problem in underdeveloped countries. Emerging infectious diseases, beyond current laboratory detection capabilities, combined with global travel, pose unknown imminent risks everywhere. We also briefly discuss the current risks of transfusion-transmitted infections.

We review currently available hemostatic blood products, their compositions, and their clinical indications; we mention product modifications currently in development; and we touch upon the hemostatic properties and drawbacks of whole blood, which is currently gaining popularity as an alternative to split blood products. We conclude with an in-depth overview of the risks associated with transfusion, including incompatibility, hemolytic transfusion reactions, transfusion-associated circulatory overload (TACO), and transfusion-related acute lung injury (TRALI).

Transfusion-associated circulatory overload in Ireland: a review of cases reported to the National Haemovigilance Office 2000 to 2010

BACKGROUND

Transfusion-associated circulatory overload (TACO) is an increasingly reported condition but symptoms and signs are still unrecognized. We present a review of the incidence and clinical features of TACO reported to the National Haemovigilance Office at the Irish Blood Transfusion Service.

STUDY DESIGN AND METHODS

Between 2000 and 2010, a total of 1071 cases of serious transfusion-related reactions were reported, of which 221 (21%) cases were TACO.

RESULTS

A total of 2,000,684 blood components were issued, with a TACO incidence of one in 9177. The TACO incidence per red blood cells, plasma, and platelet components issued was one in 8000, one in 16,000, and one in 57,884, respectively. The majority of cases (68%, n = 151) were elderly patients, while no sex difference was seen. Twenty-eight (13%) patients experienced severe morbidity; 31 (14%) deaths were reported, of which five (2%) were considered due to TACO and the other deaths considered due to and underlying conditions, which in most cases were cardiovascular (76%). An increased risk of mortality was found in patients on diuretics either before transfusion as part of their routine therapy or given as pretransfusion medication (odds ratio, 2.49; 95% confidence interval, 1.06-6.01). In 19 (21%) cases, TACO reaction was due to human error.

CONCLUSIONS

The strong association between TACO and human errors supports the role of hemovigilance and of adequate transfusion medicine teaching for preventing morbidity and mortality associated with TACO.

Recognition, Investigation and Management of Acute Transfusion Reactions: Consensus guidelines for Oman

The recognition and management of transfusion reactions (TRs) are critical to ensure patient safety during and after a blood transfusion. Transfusion reactions are classified into acute transfusion reactions (ATRs) or delayed transfusion reactions, and each category includes different subtypes. Different ATRs share common signs and symptoms which can make categorisation difficult at the beginning of the reaction. Moreover, TRs are often under-recognised and under-reported. To ensure uniform practice and safety, it is necessary to implement a national haemovigilance system and a set of national guidelines establishing policies for blood transfusion and for the detection and management of TRs. In Oman, there are currently no local TR guidelines to guide physicians and hospital blood banks. This paper summarises the available literature and provides consensus guidelines to be used in the recognition, management and reporting of ATRs.

[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.

A retrospective review of patient factors, transfusion practices, and outcomes in patients with transfusion-associated circulatory overload

Transfusion-associated circulatory overload (TACO) is a common yet underrecognized and underreported complication of transfusion associated with significant morbidity and mortality. The objective of this study was to examine patient and transfusion characteristics in a cohort of TACO cases. A retrospective medical record review of 100 consecutive TACO episodes reported at 2 academic centers was performed. Information related to demographics, medical history, radiologic and echocardiographic investigations, infusion practices, reaction features, management, and outcome were collected. Ninety-eight cases were accessible for review. A history of congestive heart failure (41%), renal dysfunction (44%), and age more than 70 years (56%) were common in TACO patients. Suboptimal fluid status management and inappropriate infusion practices were often seen (eg, verbal orders, double red cell transfusions, rapid infusion rates, lack or improper timing of preemptive diuretics). The median volume of blood ordered was 500 mL, and the median volume of crystalloid or colloid (preceding 24 hours) was 2200 mL. A physician order specifying the infusion rate was documented in 50% of transfusion orders. Preemptive diuretics were ordered in only 29% of cases, most commonly introduced midway or after the transfusion at a dose of furosemide 20 mg intravenously. After TACO, 18% of patients required transfer to the intensive care unit, 8% suffered a major complication, and 2% died. Suboptimal ordering and infusion practices may be contributing to the high incidence and severity of TACO. Research in TACO prevention strategies, such as slow rates of infusion and preemptive diuretics, is warranted.

Transfusion-related acute lung injury: a clinical review

Three decades ago, transfusion-related acute lung injury (TRALI) was considered a rare complication of transfusion medicine. Nowadays, the US Food and Drug Administration acknowledge the syndrome as the leading cause of transfusion-related mortality. Understanding of the pathogenesis of TRALI has resulted in the design of preventive strategies from a blood-bank perspective. A major breakthrough in efforts to reduce the incidence of TRALI has been to exclude female donors of products with high plasma volume, resulting in a decrease of roughly two-thirds in incidence. However, this strategy has not completely eradicated the complication. In the past few years, research has identified patient-related risk factors for the onset of TRALI, which have empowered physicians to take an individualised approach to patients who need transfusion.

Soluble isoform of the receptor for advanced glycation end products as a biomarker for postoperative respiratory failure after cardiac surgery

Purpose

Postoperative respiratory failure is a major problem which can prolong the stay in the intensive care unit in patients undergoing cardiac surgery. We measured the serum levels of the soluble isoform of the receptor for advanced glycation end products (sRAGE), and we studied its association with postoperative respiratory failure.

Methods

Eighty-seven patients undergoing elective cardiac surgery were enrolled in this multicenter observational study in three university hospitals. Serum biomarker levels were measured perioperatively, and clinical data were collected for 7 days postoperatively. The duration of mechanical ventilation was studied for 28 days.

Results

Serum levels of sRAGE elevated immediately after surgery (median, 1751 pg/mL; interquartile range (IQR) 1080–3034 pg/mL) compared with the level after anesthetic induction (median, 884 pg/mL; IQR, 568–1462 pg/mL). Postoperative sRAGE levels in patients undergoing off-pump coronary artery bypass grafting (median, 1193 pg/mL; IQR 737–1869 pg/mL) were significantly lower than in patients undergoing aortic surgery (median, 1883 pg/mL; IQR, 1406–4456 pg/mL; p = 0.0024) and valve surgery (median, 2302 pg/mL; IQR, 1447–3585 pg/mL; p = 0.0005), and postoperative sRAGE correlated moderately with duration of cardiopulmonary bypass (r_s = 0.44, p<0.0001). Receiver operating characteristic curve analysis demonstrated that postoperative sRAGE had a predictive performance with area under the curve of 0.81 (95% confidence interval 0.71–0.88) for postoperative respiratory failure, defined as prolonged mechanical ventilation >3 days. The optimum cutoff value for prediction of respiratory failure was 3656 pg/mL, with sensitivity and specificity of 62% and 91%, respectively.

Conclusions

Serum sRAGE levels elevated immediately after cardiac surgery, and the range of elevation was associated with the morbidity of postoperative respiratory failure. Early postoperative sRAGE levels appear to be linked to cardiopulmonary bypass, and may have predictive performance for postoperative respiratory failure; however, large-scale validation studies are needed.

Serum levels of N-terminal proB-type natriuretic peptide in mechanically ventilated critically ill patients--relation to tidal volume size and development of acute respiratory distress syndrome

Background

Serum levels of N–terminal proB–type natriuretic peptide (NT–proBNP) are elevated in patients acute respiratory distress syndrome (ARDS). Recent studies showed a lower incidence of acute cor pulmonale in ARDS patients ventilated with lower tidal volumes. Consequently, serum levels of NT–proBNP may be lower in these patients.

We investigated the relation between serum levels of NT–proBNP and tidal volumes in critically ill patients without ARDS at the onset of mechanical ventilation.

Methods

Secondary analysis of a randomized controlled trial of lower versus conventional tidal volumes in patients without ARDS. NT–pro BNP were measured in stored serum samples. Serial serum levels of NT–pro BNP were analyzed controlling for acute kidney injury, cumulative fluid balance and presence of brain injury. The primary outcome was the effect of tidal volume size on serum levels of NT–proBNP. Secondary outcome was the association with development of ARDS.

Results

Samples from 150 patients were analyzed. No relation was found between serum levels of NT–pro BNP and tidal volume size. However, NT-proBNP levels were increasing in patients who developed ARDS. In addition, higher levels were observed in patients with acute kidney injury, and in patients with a more positive cumulative fluid balance.

Conclusion

Serum levels of NT–proBNP are independent of tidal volume size, but are increasing in patients who develop ARDS.

Approach of using established and new laboratory tests to more comprehensively investigate noninfectious and nonhemolytic transfusion reactions--along with the experience in Japan

BACKGROUND AND OBJECTIVES

Noninfectious and nonhaemolytic transfusion reactions are the most common type of transfusion reactions. Several new tests have been made, helping diagnosis and understanding of their pathogenesis. This manuscript provides a review of the literature on currently available tests in association with the approach in Japan.

MATERIALS & METHODS

Primarily by using key words, more than 100 pertinent articles in the Medline database were identified and reviewed.

RESULTS

Numbers of laboratory tests are available including those for plasma protein levels, plasma protein antibodies, leucocyte and platelet antibodies, serum N-terminal-pro-brain natriuretic peptide levels, serum tryptase levels and genetic microchimerism. Cross-match tests, such as basophil activation test and neutrophil activation test, are also available to determine a causal relationship between the reaction and transfusion.

CONCLUSIONS

Several tests should help to confirm diagnosis and determine causal relationship between adverse reactions and transfusion and to gain an insight into the mechanism of the reaction in some cases, although some of the recently developed tests have not been completely validated.

Risk factors and outcomes in transfusion-associated circulatory overload

BACKGROUND

Transfusion-associated circulatory overload is characterized by new respiratory distress and hydrostatic pulmonary edema within 6 hours after blood transfusion, but its risk factors and outcomes are poorly characterized.

METHODS

Using a case control design, we enrolled 83 patients with severe transfusion-associated circulatory overload identified by active surveillance for hypoxemia and 163 transfused controls at the University of California, San Francisco (UCSF) and Mayo Clinic (Rochester, Minn) hospitals. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using multivariable logistic regression, and survival and length of stay were analyzed using proportional hazard models.

RESULTS

Transfusion-associated circulatory overload was associated with chronic renal failure (OR 27.0; 95% CI, 5.2-143), a past history of heart failure (OR 6.6; 95% CI, 2.1-21), hemorrhagic shock (OR 113; 95% CI, 14.1-903), number of blood products transfused (OR 1.11 per unit; 95% CI, 1.01-1.22), and fluid balance per hour (OR 9.4 per liter; 95% CI, 3.1-28). Patients with transfusion-associated circulatory overload had significantly increased in-hospital mortality (hazard ratio 3.20; 95% CI, 1.23-8.10) after controlling for Acute Physiology and Chronic Health Evaluation-II (APACHE-II) score, and longer hospital and intensive care unit lengths of stay.

CONCLUSIONS

The risk of transfusion-associated circulatory overload increases with the number of blood products administered and a positive fluid balance, and in patients with pre-existing heart failure and chronic renal failure. These data, if replicated, could be used to construct predictive algorithms for transfusion-associated circulatory overload, and subsequent modifications of transfusion practice might prevent morbidity and mortality associated with this complication.

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.

Adverse effects of plasma transfusion

Plasma utilization has increased over the past two decades, and there is a growing concern that many plasma transfusions are inappropriate. Plasma transfusion is not without risk, and certain complications are more likely with plasma than other blood components. Clinical and laboratory investigations of the patients suffering reactions after infusion of fresh-frozen plasma (FFP) define the etiology and pathogenesis of the panoply of adverse effects. We review here the pathogenesis, diagnosis, and management of the risks associated with plasma transfusion. Risks commonly associated with FFP include: 1) transfusion-related acute lung injury, 2) transfusion-associated circulatory overload, and 3) allergic and/or anaphylactic reactions. Other less common risks include 1) transmission of infections, 2) febrile nonhemolytic transfusion reactions, 3) red blood cell alloimmunization, and 4) hemolytic transfusion reactions. The effects of pathogen inactivation or reduction methods on these risks are also discussed. Fortunately, a majority of the adverse effects are not lethal and are adequately treated in clinical practice.

Risks of transfusion

Each year, more than 4 million patients receive a blood transfusion in the United States to control symptoms associated with anemia, coagulopathy, thrombocytopenia, or some combination thereof. In each of these cases, the physician and the patient must weigh the potential benefits of the transfusion along with the associated risks. To assess accurately the risk:benefit ratio and to discuss this with the patient, the physician must be familiar with the range of adverse transfusion outcomes and the current estimates of their frequency. Most important, during the past decade the risk profile of transfusion has changed significantly. Transfusion-transmitted disease, although still a rare outcome of transfusion, is no longer an overriding concern in transfusion safety considerations; however, risks such as hemolysis, transfusion-related lung injury, and anaphylaxis continue to represent significant concerns and are relatively more common than the transmission of infectious diseases after transfusion. Against this background, the development of a national hemovigilance system, designed to evaluate more accurately transfusion adverse outcomes in the United States, will require greater precision and reliability in the assessment of adverse transfusion outcomes by clinicians if the proposed benefits of this system are to be realized.

Decision support tool for early differential diagnosis of acute lung injury and cardiogenic pulmonary edema in medical critically ill patients

BACKGROUND

At the onset of acute hypoxic respiratory failure, critically ill patients with acute lung injury (ALI) may be difficult to distinguish from those with cardiogenic pulmonary edema (CPE). No single clinical parameter provides satisfying prediction. We hypothesized that a combination of those will facilitate early differential diagnosis.

METHODS

In a population-based retrospective development cohort, validated electronic surveillance identified critically ill adult patients with acute pulmonary edema. Recursive partitioning and logistic regression were used to develop a decision support tool based on routine clinical information to differentiate ALI from CPE. Performance of the score was validated in an independent cohort of referral patients. Blinded post hoc expert review served as gold standard.

RESULTS

Of 332 patients in a development cohort, expert reviewers (κ, 0.86) classified 156 as having ALI and 176 as having CPE. The validation cohort had 161 patients (ALI = 113, CPE = 48). The score was based on risk factors for ALI and CPE, age, alcohol abuse, chemotherapy, and peripheral oxygen saturation/Fio(2) ratio. It demonstrated good discrimination (area under curve [AUC] = 0.81; 95% CI, 0.77-0.86) and calibration (Hosmer-Lemeshow [HL] P = .16). Similar performance was obtained in the validation cohort (AUC = 0.80; 95% CI, 0.72-0.88; HL P = .13).

CONCLUSIONS

A simple decision support tool accurately classifies acute pulmonary edema, reserving advanced testing for a subset of patients in whom satisfying prediction cannot be made. This novel tool may facilitate early inclusion of patients with ALI and CPE into research studies as well as improve and rationalize clinical management and resource use.