Transfusion reactions in pediatric compared with adult patients: a look at rate, reaction type, and associated products

Investigation of factors associated with allergic transfusion reaction due to platelet transfusion and the efficacy of platelets resuspended in BRS-A in adult patients

BACKGROUND

Although allergic transfusion reactions (ATRs) resulting from platelet concentrate (PC) are a common adverse reaction, the mechanism underlying ATRs has not been fully elucidated. Plasma-replaced PC suspended in bicarbonate Ringer's solution and anticoagulant citrate dextrose solution A (RPC-B) is effective for preventing ATRs in children in Japan; however, there is not enough evidence in adult populations.

STUDY DESIGN AND METHODS

We conducted a retrospective analysis focused on factors associated with ATRs developing from PC transfusions in adult patients in a single institution between 2015 and 2018. The clinical efficacy of RPC-B for adult patients was also analyzed.

RESULTS

In total, 4,677 untreated regular PC products in plasma were transfused into 914 patients. ATRs developed in 65 patients (7.1%) treated with 92 PC products (2.0%). Multivariate analysis revealed that patients who were elderly, diagnosed with a non-hematological disease, and who received a transfusion of fresh-frozen plasma and red blood cell concentrate products together with PC products had lower frequencies of ATRs. Although 40 patients received 490 RPC-B transfusions, six ATRs (1.2%) were confirmed in five patients (12.5%). The ATR frequency was not significantly lower in the analysis of all patients; however, ATRs in patients with hematological diseases were lower in terms of both the patient and product numbers. Corrected count increments (24 hr) were also within an acceptable range in patients with hematological diseases.

CONCLUSION

Several patient-specific factors may be associated with the development of ATRs from PC transfusion. Because RPC-B appears to efficiently prevent ATRs, even in adult patients, safe and efficient transfusions may be performed by using RPC-B preferentially depending on the patient's risk factors.

Adverse transfusion reactions in transfused children

Transfusion in paediatrics requires specific guidelines, because child physiology and pathology differ significantly as compared to adults. Adverse transfusion reactions in transfused children also vary in type and frequency, but there is a better understanding of these reactions in adults than in children. However, for the most frequent adverse transfusion reactions, the overall prevalence is higher in children than in adults, with the exception of post-transfusion red blood cell alloimmunisation, which is lower, excluding patients with haemoglobinopathies. In several studies, allergic reactions were the most frequently reported adverse transfusion reaction in paediatrics, and the platelet concentrate the most frequently implicated blood product. Early diagnosis of certain adverse transfusion reactions such as haemosiderosis, is essential in order to initiate the best therapy and obtain a good clinical outcome. The prevention of adverse transfusion reactions in children is required, but needs further clinical studies in paediatrics. Lastly, changes in technology, policy and clinical practices will improve transfusion safety in children.

Burnout and perceived social support: The mediating role of secondary traumatization in nurses vs. physicians

AIMS

The study aimed to examine differences between paediatric nurses and physicians regarding burnout syndrome, secondary traumatic stress (STS) and perceived social support (PSS).

BACKGROUND

Paediatric nurses and physicians encounter cumulative effects of treating sick and injured children and helping their families, in situations that might promote burnout and STS.

DESIGN

Cross-sectional design.

METHOD

Nurses (n = 158) and physicians (N = 76) completed self-report questionnaires on STS, PSS and burnout.

RESULTS

Nurses and physicians had similar rates of STS and burnout but showed significant differences in PSS. Furthermore, STS mediated the association between PSS and burnout for both groups; however, the effect was stronger for nurses in comparison to physicians.

CONCLUSION

Paediatric nurses and physicians would benefit from participating in interventions geared towards reducing STS, thus minimizing burnout. Moreover, advocating social support within the organization is needed to bolster the ability for coping with sources of stress.

IMPACT STATEMENT

Nurses' and physicians' involvement in the physical, physiological and mental needs of their paediatric patients might lead to burnout and secondary traumatic stress (STS). However, research on social support in the context of burnout and STS among nurses and physicians is scant. Secondary traumatic stress and burnout were similar for nurses and physicians, though perceived social support (PSS) was higher for nurses. Secondary traumatic stress plays a mediating role in the association between PSS and burnout among nurses and physicians. However, the mediation effect was stronger for nurses. Policy makers would be wise to advocate institutional stress management interventions to reduce secondary traumatic and to reinforce organizational support for nurses and physicians.

New Approaches and Trials in Pediatric Transfusion Medicine

Blood transfusions are frequently lifesaving, but there is growing awareness of their associated infectious and noninfectious adverse events. Patient blood management advocates for judicious use of transfusions and considerations of alternatives to correct anemia or achieve hemostasis. Several transfusion practices, either already implemented or under investigation, aim to further improve the safety of transfusions. An enduring challenge in pediatric and neonatal transfusion practice is that studies typically focus on adults, and findings are extrapolated to younger patients. This article aims to summarize some of the newer developments in transfusion medicine with a focus on the neonatal and pediatric population.

Mild Allergic Transfusion Reactions: Impact of Associated Clinical Symptoms?

Objectives

Transfusions are often needlessly aborted after occurrence of a mild allergic transfusion reaction (ATR), leading to wastage and reexposure of recipients to additional blood products (with potential alloimmunization). We aimed to determine the symptoms associated with such reactions (along with other parameters) as a possible reason of concern for transfusionists aborting such transfusions.

Methods

We reviewed the symptomology of all mild ATRs (as well as the associated wastage and costs of aborted transfusions) at an academic medical center that occurred over a period of 1 year.

Results

Of the patients, 52.3% had nonatopic-associated symptoms. The most common associated symptom was tachycardia (37.8%), followed by dyspnea (28.9%), hypotension (17.8%), and hypertension (13.3%). More than half of patients (54.7%) required retransfusion. The estimated cost of product wastage was $12,507.

Conclusions

Understanding symptoms associated with mild ATRs may lead to improved management of patients, with fewer unnecessary transfusions and less wastage.

Piloting and implementation of quality assessment and quality control procedures in RBC-Omics: a large multi-center study of red blood cell hemolysis during storage

BACKGROUND

The major aims of the RBC-Omics study were to evaluate the genomic and metabolomic determinants of spontaneous and stress-induced hemolysis during RBC storage. This study was unique in scale and design to allow evaluation of RBC donations from a sufficient number of donors across the spectrum of race, ethnicity, sex, and donation intensity. Study procedures were carefully piloted, optimized, and controlled to enable high-quality data collection.

METHODS

The enrollment goal of 14,000 RBC donors across four centers, with characterization of RBC hemolysis across two testing laboratories, required rigorous piloting and optimization and establishment of a quality assurance (QA) and quality control (QC) program. Optimization of WBC elution from leukoreduction (LR) filters, development and validation of small-volume transfer bags, impact of manufacturing and sample-handling procedures on hemolysis parameters, and testing consistency across laboratories and technicians and over time were part of this quality assurance/quality control program.

RESULTS

LR filter elution procedures were optimized for obtaining DNA for analysis. Significant differences between standard and pediatric storage bags led to use of an alternative LR-RBC transfer bag. The impact of sample preparation and freezing methods on metabolomics analyses was evaluated. Proficiency testing monitored and documented testing consistency across laboratories and technicians.

CONCLUSION

Piloting and optimization, and establishment of a robust quality assurance/quality control program documented process consistency throughout the study and was essential in executing this large-scale multicenter study. This program supports the validity of the RBC-Omics study results and a sample repository that can be used in future studies.

Recommendations on Selection and Processing of RBC Components for Pediatric Patients From the Pediatric Critical Care Transfusion and Anemia Expertise Initiative

OBJECTIVES

To present the recommendations and supporting literature for selection and processing of RBC products in critically ill children developed by 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 clinical recommendations as well as research priorities for RBC transfusions in critically ill children. The RBC processing subgroup included five experts. Electronic searches were conducted using PubMed, EMBASE, and Cochrane Library databases from 1980 to May 2017. Agreement was obtained using the Research and Development/UCLA Appropriateness Method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method.

RESULTS

Five recommendations reached agreement (> 80%). Irradiated cellular products are recommended for children at risk of transfusion-associated graft versus host disease due to severe congenital or acquired causes of immune deficiency or when the blood donor is a blood relative. Washed cellular blood components and avoidance of other plasma-containing products are recommended for critically ill children with history of severe allergic reactions or anaphylaxis to blood transfusions, although patient factors appear to be important in the pathogenesis of reactions. For children with history of severe allergic transfusion reactions, evaluation for allergic stigmata prior to transfusion is recommended. In children with severe immunoglobulin A deficiency with evidence of antiimmunoglobulin A antibodies and/or a history of a severe transfusion reaction, immunoglobulin A-deficient blood components obtained either from an immunoglobulin A-deficient donor and/or washed cellular components is recommended.

CONCLUSIONS

The Transfusion and Anemia Expertise Initiative consensus conference developed recommendations for selection and processing of RBC units for critically ill children. Recommendations in this area are largely based on pediatric and adult case report data.

Patient blood management, what does this actually mean for neonates and infants?

Patient blood management (PBM) refers to an evidence-based package of care that aims to improve patient outcomes by optimal use of transfusion therapy, including managing anaemia, preventing blood loss and improving anaemia tolerance in surgical and other patients who may need transfusion. In adults, PBM programmes are well established, yet the definition and implementation of PBM in neonates and children lags behind. Neonates and infants are frequently transfused, yet they are often under-represented in transfusion trials. Adult PBM programmes may not be directly applicable to these populations. We review the literature in neonatal (and applicable paediatric) transfusion medicine and propose specific neonatal PBM definitions and elements.

The use of antifibrinolytics in pediatric patients with hypoproliferative thrombocytopenia

Despite the use of evidence-based platelet transfusion therapy during periods of hypoproliferative thrombocytopenia, a large proportion of pediatric hematology/oncology patients continue to suffer from clinically significant bleeding. Antifibrinolytic (AF) drugs have been shown in certain surgical and trauma settings to decrease bleeding, blood transfusion, and improve survival. We conducted a retrospective assessment of the safety of using AF drugs in pediatric patients with hypoproliferative thrombocytopenia at our center as well as the impact on bleeding occurrence and severity.

What Should Define Preoperative Anemia in Primary THA?

BACKGROUND

The use of tranexamic acid (TXA) in THA decreases the risk of transfusion after surgery. However, nearly 10% of patients still undergo a transfusion, which has been independently associated with an increased risk of complications. Preoperative anemia has been proven to be a strong predictor of transfusion after THA, but the ideal "cutoff" values in today's population that maximize sensitivity and specificity to predict transfusion have yet to be established.

QUESTIONS/PURPOSES

(1) Which preoperative factors are associated with postoperative transfusion in the setting of TXA use? (2) If preoperative hemoglobin (Hgb) remains associated with transfusion, what are the best-supported preoperative Hgb cutoff values associated with increased transfusion after THA?

METHODS

A retrospective chart analysis was performed from January 1, 2013, to January 1, 2015, on 558 primary THAs that met prespecified inclusion criteria. A multivariable logistic regression analysis model was used to identify independent factors associated with transfusion. Area under the receiver-operator curve (AUC) was used to determine the best-supported preoperative Hgb cut point across all participants, as well as adjusted by sex and TXA use. Overall, 60 patients with a blood transfusion were included and compared with 498 control subjects (11% risk of transfusion).

RESULTS

After controlling for potential confounding variables such as age, sex, American Society of Anesthesiologist score, intravenous TXA (IV TXA) use, and preoperative Hgb, we found that patients with lower preoperative Hgb (g/dL per 1-unit decrease, odds ratio [OR], 2.6; 95% CI, 2.0-3.5; p < 0.001), female sex (vs male, OR, 4.2; 95% CI, 1.7-10.3; p = 0.002), and those unable to receive IV TXA (topical TXA/no TXA, OR, 13.5; 95% CI, 6.3-28.6; p < 0.001) were more likely to receive a transfusion. Of these, preoperative Hgb was found to be the variable most highly associated with transfusion (AUC, 0.876). A preoperative Hgb cutoff value of 12.6 g/dL maximized the AUC (0.876) for predicting transfusion across all patients unadjusted for baseline characteristics (sensitivity = 83, specificity = 84) with values of 12.5 g/dL (sensitivity = 85, specificity = 77) and 13.5 g/dL (sensitivity = 92, specificity = 77) for women and men, respectively.

CONCLUSIONS

The 1968 WHO definitions of anemia (preoperative Hgb < 13 g/dL for men and < 12 g/dL for women) used currently may underestimate patients at risk of transfusion after THA today. Further studies are needed to see if blood conservation referral decreases the risk of transfusion with preoperative treatment of anemia.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Platelet Transfusion Thresholds Among Children Admitted to a Pediatric Intensive Care Unit

Objective To evaluate the threshold for platelet transfusion in children admitted to a pediatric intensive care unit (PICU). This is a retrospective chart review study, conducted at our tertiary level PICU and is related to critically ill pediatric patients who required platelet transfusion. Methods We retrieved the target patient population data from our blood bank database. The patients were subdivided into four subgroups: hematologic (hematologic malignancies, bone marrow suppression, hemolytic anemia, and sickle cell disease), surgical (post-surgical, trauma and acute bleeding), the unstable fraction of inspired oxygen (FiO₂ > 0.6 and/or inotropic support), and the stable patients. Critically ill children between one month and 21 years of age were enrolled. We excluded patients who underwent extracorporeal membrane oxygenation (ECMO). Results A total of 197 transfusion episodes in 64 patients were analyzed. The distribution of transfusions episodes included hematologic 82% (n=161), surgical 7% (n=13), unstable 8% (n=16), stable 3% (n=7). The mean standard deviation (SD) of pre-transfusion platelet count (x1000) in all the patients and children in hematologic, surgical, unstable and stable groups were 29 (22), 29 (19), 47 (46), 28 (19), and 24 (14), respectively. The platelet count threshold for transfusion among the surgical group was higher compared to hematologic and unstable groups (p <0.001; analysis of variance (ANOVA) with multiple comparison tests). The mean platelet count during all episodes increased from 29 (22) to 71 (57) (p <0.05; paired t-test). The post-transfusion increase in platelet count was significantly higher among surgical and unstable patients compared to hematologic patients (p <0.001; ANOVA with multiple comparison tests). Conclusion The most common indication for platelet transfusion in the pediatric intensive care unit (PICU) is the underlying hematologic condition. The platelet count threshold for transfusion varied with the clinical condition and is higher among the surgical patients. The rise of platelet count after transfusion was higher among the surgical and unstable patients.

Detecting Pharmaceuticals in the Red Blood Cell Inventory of a Hospital Blood Bank

We tested 220 red blood cell units for the presence of pharmaceuticals; 15 units (6.8%) were confirmed to contain low concentrations of opiates, benzodiazepines, stimulants, or barbiturates. Further study is needed to determine whether these drugs, which are not prohibited in donated blood by current Food and Drug Administration standards, could mediate adverse reactions in children.

Analysis of pediatric adverse reactions to transfusions

BACKGROUND

Children are known to be physiologically and biochemically different from adults. However, there are no multi-institutional studies examining the differences in the frequency, type, and severity of transfusion reactions in pediatric versus adult patients. This study aims to characterize differences between pediatric and adult patients regarding adverse responses to transfusions.

STUDY DESIGN AND METHODS

This is a retrospective data analysis of nine children's hospitals and 35 adult hospitals from January 2009 through December 2015. Included were pediatric and adult patients who had a reported reaction to transfusion of any blood component. Rates are reported as per 100,000 transfusions for comparison between pediatric and adult patients.

RESULTS

Pediatric patients had an overall higher reaction rate compared to adults: 538 versus 252 per 100,000 transfusions, notably higher for red blood cell (577 vs. 278 per 100,000; p < 0.001) and platelet (833 vs. 358 per 100,000; p < 0.001) transfusions. Statistically higher rates of allergic reactions, febrile nonhemolytic reactions, and acute hemolytic reactions were observed in pediatric patients. Adults had a higher rate of delayed serologic transfusion reactions, delayed hemolytic transfusion reactions, and transfusion-associated circulatory overload.

CONCLUSION

Pediatric patients had double the rate of transfusion reactions compared to adults. The nationally reported data on reaction rates are consistent with this study's findings in adults but much lower than the observed rates for pediatric patients. Future studies are needed to address the differences in reaction rates, particularly in allergic and febrile reactions, and to further address blood transfusion practices in the pediatric patient population.

Leukocyte and plasma activation profiles in chronically transfused patients with a history of allergic reactions

BACKGROUND

Allergic transfusion reactions are drawbacks to the benefits of transfusion. Classically, allergic transfusion reactions depend on histamine release from mast cells or basophils, but other leukocyte subsets may also be important. Thus, we propose to better define the exact leukocyte subsets involved in allergic transfusion reactions.

STUDY DESIGN AND METHODS

The overall objective of the current study was to compare the activation of specific peripheral blood leukocyte subsets (monocytes, neutrophils, eosinophils, and basophils) in a cohort of 13 patients who received chronic transfusions and had a history of allergic transfusion reactions compared with a control group of patients who received chronic transfusions and had no history of allergic transfusion reactions. Leukocyte subsets were analyzed by flow cytometry at baseline and after red blood cell transfusion, and cytokine levels in platelet-free plasma collected at the same time points were measured by Luminex assay.

RESULTS

Flow cytometry and cytokine profiles before and after transfusion did not differ significantly between patients who did and did not have a history of allergic transfusion reactions (p > 0.05). However, post-transfusion samples from both groups showed a decrease in CD63 expression in basophils, monocytes, and eosinophils and a decrease in CD45 expression in all leukocyte subsets compared with pretransfusion samples. Interleukin 10 levels increased after transfusion in the group with a history of allergic transfusion reactions (p = 0.0469), and RANTES (regulated upon activation, normal T-cell expressed and secreted) was significantly decreased post-transfusion in all patients (p = 0.0122).

CONCLUSION

None of the leukocyte subsets from patients who had a history of allergic transfusion reactions significantly increased in activation either before or after transfusion. All leukocyte subsets from patients who did and did not have a history of allergic transfusion reactions decreased in their activation profile upon transfusion challenge.

Clinical Pattern in Hypotensive Transfusion Reactions

BACKGROUND

Hypotensive transfusion reactions (HyTRs) may be underreported and have been associated with patients taking angiotensin-converting enzyme inhibitors (ACEIs) receiving poststorage leukoreduced blood products through negatively charged filters. Although bedside leukoreduction is no longer commonplace, HyTRs still occur and are insufficiently characterized in the prestorage leukoreduction era. We describe recently reported cases at our institution.

METHODS

We reviewed transfusion reaction records at Stanford Healthcare from January 2014 to April 2015. HyTRs were defined by National Health Safety Network Hemovigilance Module classification.

RESULTS

Eleven HyTRs occurred in 10 patients. All were adults (mean age 71.7 years; range 45-92 years), 7 were male, and all underwent major surgery 0 to 2 days before the reaction. Nine patients underwent cardiac or vascular surgery, and all 10 were taking ACEIs with the last dose taken within 48 hours of the transfusion reaction in 9 patients. Nine patients were on extracorporeal circuits within 24 hours before the reaction (median duration 180 minutes; range 87-474 minutes). In 5 reactions, the implicated unit was restarted with resultant recurrent hypotension. Implicated units included 9 packed red blood cells, 1 apheresis platelet, and 1 plasma frozen within 24 hours.

CONCLUSIONS

Contrary to what has been previously reported in the era of prestorage leukoreduction, HyTRs at our institution showed consistent patterns in patients at risk. Patients scheduled to undergo major surgery with cardiopulmonary bypass may benefit from earlier preoperative cessation of ACEIs or temporarily switching to an alternative drug class.

Platelet Transfusions in Pediatric Intensive Care

OBJECTIVES

To characterize the determinants of platelet transfusion in a PICU and determine whether there exists an association between platelet transfusion and adverse outcomes.

DESIGN

Prospective observational single center study, combined with a self-administered survey.

SETTING

PICU of Sainte-Justine Hospital, a university-affiliated tertiary care institution.

PATIENTS

All children admitted to the PICU from April 2009 to April 2010.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

Among 842 consecutive PICU admissions, 60 patients (7.1%) received at least one platelet transfusion while in PICU. In the univariate analysis, significant determinants for platelet transfusion were admission Pediatric Risk of Mortality Score greater than 10 (odds ratio, 6.80; 95% CI, 2.5-18.3; p < 0.01) and Pediatric Logistic Organ Dysfunction scores greater than 20 (odds ratio, 26.9; 95% CI, 8.88-81.5; p < 0.01), history of malignancy (odds ratio, 5.08; 95% CI, 2.43-10.68; p < 0.01), thrombocytopenia (platelet count, < 50 × 10/L or < 50,000/mm) (odds ratio, 141; 95% CI, 50.4-394.5; p < 0.01), use of heparin (odds ratio, 3.03; 95% CI, 1.40-6.37; p < 0.01), shock (odds ratio, 5.73; 95% CI, 2.85-11.5; p < 0.01), and multiple organ dysfunction syndrome (odds ratio, 10.41; 95% CI, 5.89-10.40; p < 0.01). In the multivariate analysis, platelet count less than 50 × 10/L (odds ratio, 138; 95% CI, 42.6-449; p < 0.01) and age less than 12 months (odds ratio, 3.06; 95% CI, 1.03-9.10; p = 0.02) remained statistically significant determinants. The attending physicians were asked why they gave a platelet transfusion; the most frequent justification was prophylactic platelet transfusion in presence of thrombocytopenia with an average pretransfusion platelet count of 32 ± 27 × 10/L (median, 21), followed by active bleeding with an average pretransfusion platelet count of 76 ± 39 × 10/L (median, 72). Platelet transfusions were associated with the subsequent development of multiple organ dysfunction syndrome (odds ratio, 2.53; 95% CI, 1.18-5.43; p = 0.03) and mortality (odds ratio, 10.1; 95% CI, 4.48-22.7; p < 0.01).

CONCLUSIONS

Among children, 7.1% received at least one platelet transfusion while in PICU. Thrombocytopenia and active bleeding were significant determinants of platelet transfusion. Platelet transfusions were associated with the development of multiple organ dysfunction syndrome and increased mortality.

Factors related to allergic transfusion reactions and febrile non-haemolytic transfusion reactions in children

BACKGROUND AND OBJECTIVES

Allergic transfusion reactions (ATRs) and febrile non-haemolytic transfusion reactions (FNHTRs) are the two major types of transfusion-related adverse reactions (TRARs). Although prestorage leucocyte reduction and diversion of the first aliquot of blood (LR/D) could reduce FNHTRs and bacterial contamination in adult transfusion, ATRs are still problematic. In addition, there is little information about TRARs in paediatric population.

MATERIALS AND METHODS

We conducted a single-centre retrospective analysis of all transfusions, except washing products, and TRARs for 153 months to evaluate related factors such as delivery of treatment and the characteristics of recipients.

RESULTS

Most TRARs were FNHTRs and/or ATRs in children. In delivering blood products with LR/D, the frequencies of not only FNHTRs but also ATRs were significantly reduced with both platelet concentrates (PCs) and red cell concentrates (RCCs). TRARs of fresh-frozen plasma were infrequent in children. In addition, even after the introduction of LR/D, ATRs were significantly more frequent in patients with primary haematological and malignant diseases who received PCs and RCCs, older patients who received PCs and patients who received frequent RCCs.

CONCLUSION

These results suggest that leucocytes or mediators from leucocytes are underlying cause of ATRs in addition to FNHTRs in children. Furthermore, particular characteristics of patients would be other risk factors for ATRs.

Haemovigilance of reactions associated with red blood cell transfusion: comparison across 17 Countries

BACKGROUND AND OBJECTIVES

The recent establishment of the National Healthcare Safety Network Hemovigilance Module in the United States affords an opportunity to compare results with those of other developed nations.

MATERIALS AND METHODS

Using data from national haemovigilance systems, reactions associated with red blood cell (RBC) transfusion and residual risks of transfusion-transmitted infectious diseases were assembled from 17 nations. Country-specific rates of adverse events were pooled using random-effects Poisson regression.

RESULTS

Febrile non-haemolytic and delayed serologic transfusion reactions were the most frequent adverse events reported after RBC transfusion, occurring in 26 patients per 100 000 RBC units and 25 patients per 100 000 RBC units administered, respectively. Rates of allergic, febrile non-haemolytic and delayed haemolytic transfusion reactions in the United States were significantly greater than the pooled rates from other countries. Frequencies of adverse events generated from the national haemovigilance programme in the United States were considerably lower than when obtained through active surveillance.

CONCLUSION

Haemovigilance reports of adverse events in the United States are comparable to, or greater than, reports from other developed countries. Rates generated from haemovigilance programmes are lower than those obtained through active surveillance. The lack of universal leucoreduction of RBC units may be a contributing factor to the higher rate of some adverse events in the United States.

Incidence of hypotension and acute hypotensive transfusion reactions following platelet concentrate transfusions

BACKGROUND AND OBJECTIVES

Platelet concentrates (PCs) are associated with transfusion reactions involving hypotension, particularly bradykinin-mediated acute hypotensive transfusion reactions. This study aims to determine the incidence of hypotensive events and more specifically acute hypotensive transfusion reaction associated with PC transfusions. We also sought to ascertain whether these reactions are associated with elevated bradykinin levels.

MATERIALS AND METHODS

This is a prospective descriptive study of PCs administered at Sainte-Justine Hospital over 28 months. All PCs administered during this period were screened for hypotension through review of all transfusion-associated reaction reports (TARRs) sent to the blood bank. All residual PC bags were returned to the blood bank. TARRs associated with hypotension were reviewed by adjudicators that established the imputability of the PC transfusion to the reaction. Bradykinin levels were sampled in the first 168 PC bags returned to the blood bank. Levels were compared between PCs associated with hypotension and control PCs not associated with hypotension.

RESULTS

A total of 3672 PC bags were returned to the blood bank; 25 PCs were associated with hypotension. Adjudicators ascertained that five hypotensive events were imputable to PCs of which one was an acute hypotensive transfusion reaction (incidence: 0·03%). Bradykinin level in the latter PC was 10 pg/ml, whereas levels were 226·2 ± 1252 pg/ml in the 143 control PCs.

CONCLUSION

Our results show a low incidence of hypotension after PC transfusion. We identified only one acute hypotensive transfusion reaction. No correlation between bradykinin level and the occurrence of acute hypotensive reactions could be observed given that only one event was identified.