The epidemiology of platelet transfusions: an analysis of platelet use at 12 US hospitals

Isohemagglutinin titration in pooled and apheresis platelets

BACKGROUND

Platelet inventory constraints necessitate ABO-incompatible platelet transfusion. Many minimize the hemolytic impact by confirming low titre (LT) donor isohemagglutinins. This process is costly. Pathogen-reduced platelets (PRP) in platelet additive solutions (PAS) will dilute plasma and decrease high-titre isohemagglutinins (HT). We determined the proportion of HT platelets and incompatible transfusions for units suspended in plasma to reassess the need for titres following introduction of PRP/PAS.

STUDY DESIGN AND METHODS

Our titre method is manual tube (1:50) dilution of platelet supernatant from apheresis or whole blood derived buffy coat pools suspended in plasma, tested with A1/B red cells. Testing included 49,058 pooled and 11,738 apheresis platelets over 4 years. The HT proportion, rate of out-of-group transfusions, and hemolytic reactions were determined. The impact of PAS dilution was estimated.

RESULTS

Totally 60,796 platelet units were tested. Group O pooled and group B apheresis platelets had HT in 6.6% and 5.7%, respectively. Group A pooled and apheresis platelets included 2% with HT. Approximately 25% of platelets transfused were ABO-incompatible and no hemolytic reactions were reported. Based on the proportions of PAS-E and plasma for PRP platelets, plasma from each donor comprises 11 mL (6% of total volume) vs 20-257 mL in untreated pools. PAS-E will replace and dilute residual plasma by at least 50%.

DISCUSSION

Rare platelet pools may demonstrate HT. PRP platelets with PAS will reduce titres and may abrogate the need for titration. A strategy of group specific transfusion or transfusion of group A PRP platelet transfusions may be a safe alternative.

Platelet transfusions in adult ICU patients with thrombocytopenia: A sub-study of the PLOT-ICU inception cohort study

BACKGROUND

Platelet transfusions are frequently used in the intensive care unit (ICU), but current practices including used product types, volumes, doses and effects are unknown.

STUDY DESIGN AND METHODS

Sub-study of the inception cohort study 'Thrombocytopenia and Platelet Transfusions in the ICU (PLOT-ICU)', including acutely admitted, adult ICU patients with thrombocytopenia (platelet count <150 × 109/L). The primary outcome was the number of patients receiving platelet transfusion in ICU by product type. Secondary outcomes included platelet transfusion details, platelet increments, bleeding, other transfusions and mortality.

RESULTS

Amongst 504 patients with thrombocytopenia from 43 hospitals in 10 countries in Europe and the United States, 20.8% received 565 platelet transfusions; 61.0% received pooled products, 21.9% received apheresis products and 17.1% received both with a median of 2 (interquartile range 1-4) days from admission to first transfusion. The median volume per transfusion was 253 mL (180-308 mL) and pooled products accounted for 59.1% of transfusions, however, this varied across countries. Most centres (73.8%) used fixed dosing (medians ranging from 2.0 to 3.5 × 1011 platelets/transfusion) whilst some (mainly in France) used weight-based dosing (ranging from 0.5 to 0.7 × 1011 platelets per 10 kg body weight). The median platelet count increment for a single prophylactic platelet transfusion was 2 (-1 to 8) × 109/L. Outcomes of patients with thrombocytopenia who did and did not receive platelet transfusions varied.

CONCLUSIONS

Among acutely admitted, adult ICU patients with thrombocytopenia, 20.8% received platelet transfusions in ICU of whom most received pooled products, but considerable variation was observed in product type, volumes and doses across countries. Prophylactic platelet transfusions were associated with limited increases in platelet counts.

Anti-D immunization after D positive platelet transfusions in D negative recipients: A systematic review and meta-analysis

BACKGROUND

Anti-D can be formed after D-incompatible platelet transfusions due to contaminating D+ red blood cells. These antibodies are of particular importance in women of childbearing potential, because anti-D is most often involved in severe cases of hemolytic disease of the fetus and newborn. This systematic review determined the frequency of anti-D after D+ platelet transfusions and risk factors for D alloimmunization.

STUDY DESIGN AND METHODS

Relevant literature was searched using PubMed, Embase and Web of Science until December 2022. Overall anti-D frequency and risk factors were estimated using a random effects meta-analysis.

RESULTS

In 22 studies, a total of 3028 D- patients received a mean of six D+ platelet transfusions. After a mean follow-up of seven months 106 of 2808 eligible patients formed anti-D. The pooled anti-D frequency was 3.3% (95% CI 2.0-5.0%; I2 71%). After including only patients with an undoubtable follow-up of at least 4 weeks, 29 of 1497 patients formed anti-D with a pooled primary anti-D rate of 1.9% (95% CI 0.9-3.2%, I2 44%). Women and patients receiving whole blood derived platelets had two and five times higher anti-D rates compared with men and patients receiving apheresis derived platelets, respectively.

DISCUSSION

Anti-D immunization is low after D incompatible platelet transfusions and dependent on recipients' sex and platelet source. We propose anti-D prophylaxis in girls and women, capable of becoming pregnant in the future, that received D+ platelets, regardless of platelet source, to reduce the risk of anti-D induced hemolytic disease of the fetus and newborn.

Use of platelet transfusions and tranexamic acid in patients with myelodysplastic syndromes: A clinical practice survey

AIM

Thrombocytopenia and bleeding are common in myelodysplastic syndromes (MDS), but optimal management is unknown. We conducted a survey to identify current clinical practice regarding platelet transfusion (PLT-T) and tranexamic acid (TXA) to inform future trial design.

METHOD

A 25-question survey was distributed to members of the ALLG from December 2020 to July 2021.

RESULTS

Sixty-four clinicians across Australia, New Zealand and Singapore responded. Clinicians treated a median of 15 MDS patients annually. Twenty-nine (45%) reported having institutional guidelines regarding prophylactic PLT-T. Although 60 (94%) said they would consider using TXA, most (58/64; 91%) did not have institutional guidelines. Clinical scenarios showed prophylactic PLT-T was more likely administered for patients on disease-modifying therapy (49/64; 76%, commonest threshold <10 × 109 /L) or with minor bleeding (32/64 [50%] transfusing at threshold <20 × 109 /L, 23/64 [35%] at <10 × 109 /L). For stable untreated patients, 29/64 (45%) would not give PLT-T and 32/64 (50%) would. Most respondents (46/64; 72%) were interested in participating in trials in this area. Potential barriers included resource limitations, funding and patient/clinician acceptance.

CONCLUSION

Real-world management of MDS-related thrombocytopenia varies and there is a need for clinical trials to inform practice.

Cold-stored platelet hemostatic capacity is maintained for three weeks of storage and associated with taurine metabolism

BACKGROUND

Platelet (PLT) product transfusion is a life-saving therapy for actively bleeding patients. There is an urgent need to maintain PLT function and extend shelf life to improve outcomes in these patients. Cold-stored PLT (CS-PLT) maintain hemostatic potential better than room temperature-stored PLT (RT-PLT). However, whether function in long-term CS-PLT is maintained under physiological flow regimes and/or determined by cold-induced metabolic changes is unknown.

OBJECTIVES

This study aimed to (i) compare the function of RT-PLT and CS-PLT under physiological flow conditions, (ii) determine whether CS-PLT maintain function after 3 weeks of storage, and (iii) identify metabolic pathways associated with the CS-PLT lesion.

METHODS

We performed phenotypic and functional assessments of RT- and CS-PLT (22 °C and 4 °C storage, respectively; N = 10 unique donors) at storage days 0, 5, and/or 21 via metabolomics, flow cytometry, aggregation, thrombin generation, viscoelastic testing, and a microfluidic assay to measure primary hemostatic function.

RESULTS

Day 21 4 °C PLT formed an occlusive thrombus under arterial shear at a similar rate to day 5 22 °C PLT. Day 21 4 °C PLTs had enhanced thrombin generation capacity compared with day 0 PLT and maintained functionality comparable to day RT-PLT across all assays performed. Key metrics from microfluidic assessment, flow cytometry, thrombin generation, and aggregation were associated with 4 °C storage, and metabolites involved in taurine and purine metabolism significantly correlated with these metrics. Taurine supplementation of PLT during storage improved hemostatic function under flow.

CONCLUSION

CS-PLT stored for 3 weeks maintain hemostatic activity, and storage-induced phenotype and function are associated with taurine and purine metabolism.

Platelet transfusions in adult thrombocytopenic ICU patients: Protocol for a sub-study of the PLOT-ICU cohort

INTRODUCTION

Platelet transfusions are frequently used in intensive care unit (ICU) patients, but contemporary epidemiological data are sparse. We aim to present contemporary international data on the use of platelet transfusions in adult ICU patients with thrombocytopenia.

METHODS

This is a protocol and statistical analysis plan for a post hoc sub-study of 504 thrombocytopenic patients from the 'Thrombocytopenia and platelet transfusions in ICU patients: an international inception cohort study (PLOT-ICU)'. The primary outcome will be the number of patients receiving platelet transfusion in the ICU reported according to the type of product received (apheresis-derived versus pooled whole-blood-derived transfusions). Secondary platelet transfusion outcomes will include platelet transfusion volumes; timing of platelet transfusion; approach to platelet transfusion dosing (fixed dosing versus weight-based dosing) and platelet count increments for prophylactic transfusions. Secondary clinical outcomes will include the number of patients receiving red blood cell- and plasma transfusions during ICU stay; the number of patients who bled in the ICU, the number of patients who had a new thrombosis in the ICU, and the number of patients who died. The duration of follow-up was 90 days. Baseline characteristics and secondary clinical outcomes will be stratified according to platelet transfusion status in the ICU and severity of thrombocytopenia. Data will be presented descriptively.

CONCLUSIONS

The outlined study will provide detailed epidemiological data on the use of platelet transfusions in adult ICU patients with thrombocytopenia using data from the large international PLOT-ICU cohort study. The findings will inform the design of future randomised trials evaluating platelet transfusions in ICU patients.

The safety of ABO minor incompatible platelets transfusions using a rapid infuser

BACKGROUND

Administering platelets through a rapid infuser is proven to be safe. However, the clinical significance of infusing ABO-incompatible platelets with red blood cells (RBCs) in a rapid infuser remains unclear. There is a theoretical risk that isoagglutinin in the plasma of a platelet unit can interact with RBCs and induce hemolysis.

MATERIALS AND METHODS

Seven in vitro studies were performed including five cases (type A RBCs and type O platelets) and two controls (type A RBCs and platelets). Anti-A titers were measured in platelet units. An RBC unit and a platelet unit were mixed in the rapid infuser reservoir and incubated for 30 min. The primary outcome was the presence of hemolysis based on the following parameters: free hemoglobin concentration, hemolysis check, direct antiglobulin test (DAT), and direct agglutination.

RESULTS

The post-mix DAT was positive for IgG in all test samples (5/5), and weakly positive for complement in 3/5. The changes in free Hb in test cases between measured and calculated post-mix spanned -2.2 to +3.4 mg/dL. Post-mix hemolysis check was negative in 3/5 and slightly positive in 2/5 cases, with no significant differences compared to the control case. Anti-A titers ranged from 16 to 512 and were not associated with hemolysis. All samples were negative for direct agglutination.

CONCLUSION

Our study suggested that mixing ABO-incompatible platelets with RBCs in a rapid infuser does not induce in vitro hemolysis. These findings support the use of rapid infusers regardless of platelet compatibility in support of hemostatic resuscitation.

Efficiency of Platelet Transfusion in Patients with Moderate-to-Severe Chronic Kidney Disease and Thrombocytopenia

There have been relatively few studies revealing a decreased platelet count in chronic kidney disease (CKD). Although this hematological abnormality is not as well documented as renal anemia, platelet functions are altered in the uremic environment and there is an increased risk of bleeding. The aim of this study was to assess the effectiveness of the administration of platelet concentrate in CKD based on how patient prognosis was influenced by platelet transfusion therapy. The study monitored 104 patients with CKD and thrombocytopenia who received platelet transfusion during their hospitalization in the period from 2015 to 2021. The complete blood cell count, serum urea and creatinine, and inflammatory status were tested upon admission. The number of transfused platelet units were considered for each patient. A Kruskal-Wallis H test showed that for one transfused platelet unit, the distribution of the number of platelets (×103/µL) was the same across the categories of associated diagnoses, which was seen as possible risk factors for thrombocytopenia, including liver cirrhosis and urosepsis. With a single exception, all patients exceeded the critical threshold of 20 × 103/µL and 14 patients remained under 50 × 103/µL. Even though our patients exceeded the critical threshold of platelet numbers, in patients with multiple comorbidities, severe, uncontrolled hemorrhages could not be prevented in 4.83% of cases.

Loss of 12-Lipoxygenase Improves the Post-Transfusion Function of Stored Platelets

BACKGROUND

Platelets for transfusion are stored for 5 to 7 days. Previous studies have shown that HETE levels in the storage bag negatively correlate with platelet performance in vivo, suggesting that the dysregulation of bioactive lipid mediators may contribute to the storage lesion. In the current study, we sought to understand how genetic deletion and pharmacological inhibition of 12-LOX (12-lipoxygenase) affects platelets during storage and after transfusion.

METHODS

Platelets from 12-LOX+/+ (wild-type [WT]) and 12-LOX-/- mice were stored for 24 and 48 hours and profiled using liquid chromatography-tandem mass spectrometry-multiple reaction monitoring or transfused into thrombocytopenic hIL4R (human interleukin 4 receptor)-transgenic mice. Platelet function was assessed by flow cytometry and in vivo thrombosis and hemostasis models. To test the role of the COX-1 (cyclooxygenase-1) pathway, donor mice were treated with acetylsalicylic acid. Human platelets were treated with the 12-LOX inhibitor, VLX-1005, or vehicle, stored, and transfused to NOD/SCID (nonobese diabetic/severe combined immunodeficiency) mice.

RESULTS

Polyunsaturated fatty acids increased significantly in stored platelets from 12-LOX-/- mice, whereas oxylipin concentrations were significantly higher in WT platelets. After transfusion to thrombocytopenic mice, we observed significantly more baseline αIIbβ3 integrin activation in 12-LOX-/- platelets than in WT platelets. Stored platelets from 12-LOX-/- mice occluded vessels significantly faster than stored WT platelets. In hemostasis models, significantly more stored 12-LOX-/- than WT platelets accumulated at the site of venous injury leading to reduced blood loss. Inhibition of COX-1 abrogated both increased integrin activation and thromboxane generation in stored 12-LOX-/- platelets, highlighting the critical role of this pathway for improved post-transfusion function. Consistent with our mouse studies, human platelets stored with VLX-1005, showed increased integrin activation compared with vehicle-treated platelets after transfusion.

CONCLUSIONS

Deleting 12-LOX improves the post-transfusion function of stored murine platelets by increasing thromboxane generation through COX-1-dependent arachidonic acid metabolism. Future studies should determine the feasibility and safety of 12-LOX-inhibited platelets transfused to humans.

Platelet transfusions and predictors of bleeding in patients with myelodysplastic syndromes

OBJECTIVES

This study aimed to describe the burden of thrombocytopenia, supportive care practices, bleeding complications and predictors of bleeding in MDS patients within a large Australian hospital network, to better understand the use and effectiveness of platelet transfusions in MDS.

METHODS

A retrospective cohort study of patients aged ≥18 years with MDS, chronic myelomonocytic leukaemia or MDS/myeloproliferative overlap neoplasm admitted from 2016 to 2018 was conducted. Data were obtained from hospital medical records.

RESULTS

One hundred seventy-nine patients (median age 78 years, 61.5% male) were identified. The median platelet count at first admission was 90 × 109 /L. Twenty-eight (15.6%) patients had severe thrombocytopenia (platelet count <20 × 109 /L), of whom nine (32.1%) received prophylactic platelet transfusions, five (17.9%) received tranexamic acid (TXA), seven (25%) received both platelet transfusions and TXA, and seven (25%) received no treatment. Bleeding events requiring hospitalisation occurred in 20 (11.2%) patients. Bleeding was not predicted by presenting platelet count, TXA use, platelet transfusion or anticoagulant/antiplatelet therapies. Three patients died of bleeding, at varying platelet counts (18, 38 and 153 × 109 /L).

CONCLUSION

Thrombocytopenia is common in MDS. Although guidelines recommend otherwise, prophylactic platelet transfusions were commonly used for severe thrombocytopenia. Despite the majority of patients receiving platelet transfusions and/or TXA, 11% developed major bleeding occurring at a wide range of platelet counts.

Platelet transfusion in critical care: A new method to analyze transfusion practice based on decision time intervals

BACKGROUND

While prior studies of platelet transfusion in critical care have focused on transfusions given, proper analysis of clinical transfusion practice also requires consideration of the decision not to transfuse.

STUDY DESIGN AND METHODS

We introduce a new method to assess transfusion practice based on decision time intervals (DTIs). Each patient's intensive care (ICU) stay was segmented into a series of DTIs defined by a time interval following results of a complete blood count (CBC). We studied the presence of 17 clinical factors during each DTI whether transfusion was given or not. We used a generalized linear mixed model to assess the most influential clinical triggers for platelet transfusion.

RESULTS

Among 6125 ICU patients treated between October 2016 and October 2021, we analyzed 39,745 DTIs among patients (n = 2921) who had at least one DTI with thrombocytopenia (≤150,000/μL). We found no association between platelet count and two markers of bleeding: drop in hemoglobin and chest tube drainage. We found that the majority of DTIs were associated with no platelet transfusion regardless of the platelet count; that no specific platelet value triggered transfusion; but rather that multiple clinical factors in conjunction with the platelet count influenced the decision to transfuse.

DISCUSSION

DTI analysis represents a new method to assess transfusion practice that considers both transfusions given and not given, and that analyzes clinical circumstances present when decisions regarding transfusion are made. The method is easily adapted to blood components other than platelet transfusions and is easily extended to other ICU and other hospital settings.

A randomized cross-over study of cryopreserved platelets in prophylactic transfusions of thrombocytopenic patients

BACKGROUND

The short shelf-life of liquid-stored platelets (LP) at 20-24°C poses shortage and wastage challenges. Cryopreserved platelets have significantly extended shelf-life, and were safe and efficacious for therapeutic transfusions of bleeding patients in the Afghanistan conflict and phase 2 randomized studies. Although hematology patients account for half of platelets demand, there is no randomized study on prophylactic cryopreserved platelet transfusions in them.

METHODS

We performed a phase 1b/2a randomized cross-over study comparing the safety and efficacy of cryopreserved buffy coat-derived pooled platelets (CP) to LP in the prophylactic transfusions of thrombocytopenic hematology patients.

RESULTS

A total of 18 adults were randomly assigned 1:1 to CP and LP for their first thrombocytopenic period (TP) of up to 28-days. A total of 14 crossed over to the other platelet-arm for the second TP. Overall, 17 subjects received 51 CP and 15 received 52 LP. CP-arm had more treatment emergent adverse event (29.4% vs. 13.3% of subjects, 9.8% vs. 3.8% of transfusions) than LP-arm but all were mild. No thromboembolism was observed. Both arms had similar bleeding rates (23.5% vs. 26.7% of subjects) which were all mild. Subjects in CP-arm had lower average corrected count increments than LP-arm (mean [SD] 5.6 [4.20] vs. 22.6 [9.68] ×109 /L at 1-4 h, p < .001; 5.3 [4.84] vs. 18.2 [9.52] ×109 /L at 18-30 h, p < .001). All TEG parameters at 1-4 h and maximum amplitude (MA) at 18-30 h improved from baseline post-CP transfusion (p < .05) though improvements in K-time and MA were lower than LP (p < .05).

DISCUSSION

During shortages, CP may supplement LP in prophylactic transfusions of thrombocytopenic patients.

Omics markers of platelet transfusion in trauma patients

BACKGROUND

Even in the era of the COVID-19 pandemic, trauma remains the global leading cause of mortality under the age of 49. Trauma-induced coagulopathy is a leading driver of early mortality in critically ill patients, and transfusion of platelet products is a life-saving intervention to restore hemostasis in the bleeding patient. However, despite extensive functional studies based on viscoelastic assays, limited information is available about the impact of platelet transfusion on the circulating molecular signatures in trauma patients receiving platelet transfusion.

MATERIALS AND METHODS

To bridge this gap, we leveraged metabolomics and proteomics approaches to characterize longitudinal plasma samples (n = 118; up to 11 time points; total samples: 759) from trauma patients enrolled in the Control Of Major Bleeding After Trauma (COMBAT) study. Samples were collected in the field, in the emergency department (ED), and at intervals up to 168 h (7 days) post-hospitalization. Transfusion of platelet (PLT) products was performed (n = 30; total samples: 250) in the ED through 24 h post-hospitalization. Longitudinal plasma samples were subjected to mass spectrometry-based metabolomics and proteomics workflows. Multivariate analyses were performed to determine omics markers of transfusion of one, two, three, or more PLT transfusions.

RESULTS

Higher levels of tranexamic acid (TXA), inflammatory proteins, carnitines, and polyamines were detected in patients requiring PLT transfusion. Correlation of PLT units with omics data suggested sicker patients required more units and partially overlap with the population requiring transfusion of packed red blood cell products. Furthermore, platelet activation was likely increased in the most severely injured patients. Fatty acid levels were significantly lower in PLT transfusion recipients (at time of maximal transfusion: Hour 4) compared with non-recipients, while carnitine levels were significantly higher. Fatty acid levels restore later in the time course (e.g., post-PLT transfusion).

DISCUSSION

The present study provides the first multi-omics characterization of platelet transfusion efficacy in a clinically relevant cohort of trauma patients. Physiological alterations following transfusion were detected, highlighting the efficacy of mass spectrometry-based omics techniques to improve personalized transfusion medicine. More specialized clinical research studies focused on PLT transfusion, including organized pre and post transfusion sample collection and limitation to PLT products only, are required to fully understand subsequent metabolomic and proteomic alterations.

Young apheresis platelet donors show significant and sustained growth over the last decade in the US, 2010-2019: A favorable sign of the resiliency of the platelet supply

BACKGROUND

Platelet demand continues to rise and US hospitals frequently face shortages. The peak median age of apheresis platelet donors (APD) is believed to have increased over the last decade, raising concerns that the APD base is not being adequately replenished with young donors.

STUDY DESIGN/METHODS

American Red Cross (ARC) apheresis platelet collections were evaluated from calendar years 2010 through 2019. APD, products per procedure/split rate (PPP) and donation frequencies were stratified into age groups.

RESULTS/FINDINGS

The number of unique APD from calendar year 2010 through 2019 in the ARC donor pool increased from 87,573 to 115,372 donors, representing a 31.7% overall growth. Donors in the 16-40 year-old (y) age group increased by 78.8% overall, with the largest absolute increases seen in the 26-30 y (4852 donors, 99.9% growth), followed by the 31-35 y (3991, 94.1%) group. Donors aged 56+ increased by 50.4% overall, with the largest increase seen in the 66-70 y (5988 donors, 108.1% growth) group. Middle-aged donors, aged 41-55 y, demonstrated a decrease of 16.5%. Over the last decade, the youngest age groups (16-40 y) comprised 61.3% of first-time donors (FTD). Annual donation frequency increased with increasing age and PPP. The highest donation frequencies were seen in the oldest age groups.

CONCLUSION

Although the peak median age of APD increased over the study period, relative contribution of the 16-40 y APD base also increased. Older donors exhibited the highest donation frequencies and thus contributed the largest volume of apheresis platelet units. Platelet donor activity declined in the middle age (41-55 y) group.

Associations between ABO non-identical platelet transfusions and patient outcomes-A multicenter retrospective analysis

BACKGROUND

Due to platelet availability limitations, platelet units ABO mismatched to recipients are often transfused. However, since platelets express ABO antigens and are collected in plasma which may contain ABO isohemagglutinins, it remains controversial as to whether ABO non-identical platelet transfusions could potentially pose harm and/or have reduced efficacy.

STUDY DESIGN AND METHODS

The large 4-year publicly available Recipient Epidemiology and Donor Evaluation Study-III (REDS-III) database was used to investigate patient outcomes associated with ABO non-identical platelet transfusions. Outcomes included mortality, sepsis, and subsequent platelet transfusion requirements.

RESULTS

Following adjustment for possible confounding factors, no statistically significant association between ABO non-identical platelet transfusion and increased risk of mortality was observed in the overall cohort of 21,176 recipients. However, when analyzed by diagnostic category and recipient ABO group, associations with increased mortality for major mismatched transfusions were noted in two of eight subpopulations. Hematology/Oncology blood group A and B recipients (but not group O) showed a Hazard Ratio (HR) of 1.29 (95%CI: 1.03-1.62) and intracerebral hemorrhage group O recipients (but not groups A and B) showed a HR of 1.75 (95%CI: 1.10-2.80). Major mismatched transfusions were associated with increased odds of receiving additional platelet transfusion each post-transfusion day (through day 5) regardless of the recipient blood group.

DISCUSSION

We suggest that prospective studies are needed to determine if specific patient populations would benefit from receiving ABO identical platelet units. Our findings indicate that ABO-identical platelet products minimize patient exposure to additional platelet doses.

Digital polymerase chain reaction to monitor platelet transfusions in cardiac surgery patients

BACKGROUND AND OBJECTIVES

Corrected count increment (CCI) measurements monitor the effectiveness of platelet transfusions in haemato-oncology, but they usually fail in patients undergoing cardiac surgery. We investigated whether polymerase chain reaction (PCR) of mitochondrial single-nucleotide polymorphisms (SNPs) is able to monitor the survival of transfused platelets in these patients.

MATERIALS AND METHODS

Leukocyte-free, platelet-rich plasma was prepared from patients' blood to measure platelet counts based on patient-/donor-specific SNPs by digital PCR after DNA extraction. Platelet counts in samples from patients with severe thrombocytopenia were analysed by both PCR and flow cytometry. Ten patients undergoing cardiac surgery with the use of heart lung machine and without overt bleeding received a single apheresis platelet concentrate because of either dual platelet inhibition during a non-elective intervention or a complex procedure. Blood samples were collected at nine defined intervals (0-120 h) post transfusion.

RESULTS

The digital PCR of the seven SNPs reliably quantified levels ≥0.6 G/L platelets, in good agreement with flow cytometry and without interference by other SNPs or by platelet activation. A mean 24-h CCI of 11.8 (range: 5.6-19.8) and a mean 120-h area under the curve (AUC) of 1386 (915-1821) hxG/L were observed for the transfused platelets. The mean AUC of 14,103 (3415-27,305) hxG/L for the patients' endogenous platelets indicates that transfused platelets represented only 11% (5-25) of the total platelet counts during 120 h post transfusion.

CONCLUSION

PCR of mitochondrial SNPs offers a tool to assess the survival of platelets from apheresis concentrates in cardiac surgery patients to facilitate the implementation of improved transfusion strategies.

Related donor platelet transfusion improves platelet transfusion refractoriness in hematological patients

Objective

Transfusion of HLA-matched platelets can reduce the effect of alloimmune responses on platelet transfusion efficacy; however, finding HLA-matched platelets in the population is nearly impossible. Almost all HLA-matched platelets from related are half-matched, but the hemostatic efficacy of related donor platelets is unclear. Our goal was to compare the hemostatic effect of related donated platelets and unrelated donors platelets.

Methods

In this retrospective cohort study, we included acute leukemia and myelodysplastic syndrome patients with thrombocytopenia after chemotherapy. These patients were all transfused with platelets. This study excluded patients younger than 16 years and older than 65 years, or patients with abnormal coagulation parameters during platelet transfusion. We compared the hemostatic effect of related donated platelets and unrelated donors platelet. The primary outcome was transfusion efficacy after platelet transfusion, and the number of platelet counts and corrected count increments at 24 h after platelet transfusion.

Result

We analyzed 31 patients who received platelet transfusions from related donors (Treatment group) and 35 patients who received platelet transfusions from unrelated donors (Comparator group). Except for the relatively small proportion of patients with myelodysplastic syndrome in the treatment group, baseline clinical and laboratory characteristics were similar between the two groups. Hemostasis and prevention of bleeding in the treatment group showed significant superiority; the number of platelets increased 24 h after platelet transfusion in the treatment group was significantly higher than that in the comparator group. After 24 h, the corrected count increments treatment group was also higher than the comparator group; in the treatment group, the transfusion effect was better when the three sites of HLA-A, B, and C were identical, and the different blood types of platelet donors and recipients did not affect the transfusion effect.

Conclusion

Related donated platelets have better hemostasis and prevention effects, and no increase in adverse blood transfusion reactions. It may be a better transfusion strategy for platelet refractoriness patients in emergency situations.

How I use platelet transfusions

Platelet transfusions are commonly administered for the prevention or treatment of bleeding in patients with acquired thrombocytopenia across a range of clinical contexts. Recent data, including randomized trials, have highlighted uncertainties in the risk-benefit balance of this therapy, which is the subject of this review. Hemovigilance systems report that platelets are the most frequently implicated component in transfusion reactions. There is considerable variation in platelet count increment after platelet transfusion, and limited evidence of efficacy for clinical outcomes, including prevention of bleeding. Bleeding events commonly occur despite the different policies for platelet transfusion prophylaxis. The underlying mechanisms of harm reported in randomized trials may be related to the role of platelets beyond hemostasis, including mediating inflammation. Research supports the implementation of a restrictive platelet transfusion policy. Research is needed to better understand the impact of platelet donation characteristics on outcomes, and to determine the optimal thresholds for platelet transfusion before invasive procedures or major surgery (eg, laparotomy). Platelet transfusion policies should move toward a risk-adapted approach that does not focus solely on platelet count.

There and Back Again: The Once and Current Developments in Donor-Derived Platelet Products for Products for Hemostatic Therapy

Over 100 years ago, Duke transfused whole blood to a thrombocytopenic patient to raise the platelet count and prevent bleeding. Since then, platelet transfusions have undergone numerous modifications from whole blood-derived platelet-rich plasma to apheresis-derived platelet concentrates. Similarly, the storage time and temperature have changed. The mandate to store platelets for a maximum of 5-7 days at room temperature has been challenged by recent clinical trial data, ongoing difficulties with transfusion-transmitted infections, and recurring periods of shortages, further exacerbated by the COVID-19 pandemic. Alternative platelet storage approaches are as old as the first platelet transfusions. Cold-stored platelets may offer increased storage times (days) and improved hemostatic potential at the expense of reduced circulation time. Frozen (cryopreserved) platelets extend the storage time to years but require storage at -80 °C and thawing before transfusion. Lyophilized platelets can be powder-stored for years at room temperature and reconstituted within minutes in sterile water but are probably the least explored alternative platelet product to date. Finally, whole blood offers the hemostatic spectrum of all blood components but has challenges, such as ABO incompatibility. While we know more than ever before about the in vitro properties of these products, clinical trial data on these products are accumulating. The purpose of this review is to summarize the findings of recent preclinical and clinical studies on alternative, donor-derived platelet products.

Performance of Platelet Counting in Thrombocytopenic Samples: Comparison between Mindray BC-6800Plus and Sysmex XN-9000

The performance of platelet (PLT) counting in thrombocytopenic samples is crucial for transfusion decisions. We compared PLT counting and its reproducibility between Mindray BC-6800Plus (BC-6800P, Mindray, Shenzhen, China) and Sysmex XN-9000 (XN, Sysmex, Kobe, Japan), especially focused on thrombocytopenic samples. We analyzed the correlation and agreement of PLT-I channels in both analyzers and BC-6800P PLT-O mode and XN PLT-F channel in 516 samples regarding PLT counts. Ten thrombocytopenic samples (≤2.0 × 10⁹/L by XN PLT-F) were measured 10 times to investigate the reproducibility with the desirable precision criterion, 7.6%. The correlation of BC-6800P PLT-I and XN PLT-I was arranged moderate to very high; but the correlation of BC-6800P PLT-O and XN PLT-F was arranged high to very high. Both BC-6800P PLT-I vs. XN PLT-I and BC-6800P PLT-O vs. XN PLT-F showed very good agreement (κ = 0.93 and κ = 0.94). In 41 discordant samples between BC-6800P PLT-O and XN PLT-F at transfusion thresholds, BC-6800P PLT-O showed higher PLT counts than XN-PLT-F, except the one case. BC-6800P PLT-O exceeded the precision criterion in one of 10 samples; but XN PLT-F exceeded it in six of 10 samples. BC-6800P would be a reliable option for PLT counting in thrombocytopenic samples with good reproducibility.

The Impact of COVID-19 Pandemic on Blood Transfusion Services: A Perspective from Health Professionals and Donors

Purpose

Since the emergence of the COVI9-19 pandemic, there has been concern about the availability and sufficiency of blood transfusions to meet patient needs. Also, the adequate and safe blood supply is a major issue to fulfill present demands. This study aims to determine the impact of the COVID-19 pandemic on the blood transfusion service and identify solutions to overcome this impact from the perspective of blood donors and healthcare professionals.

Methods

This study was conducted prospectively among Saudi Arabian blood donors and healthcare professionals between May 2020 and May 2021. A group of professional health care professionals and blood donors participated in this study to determine the impact of the COVID-19 pandemic on blood transfusion services and identify possible solutions to overcome the adverse effects on blood system activities.

Results

To understand the impact of pandemic COVID-19 on blood transfusion services in Saudi Arabia, we investigated population dynamics and statistical analysis from different age groups and health care professionals. A total of 424 blood donors and 372 healthcare professionals participated in this study. The suggested solution by the participants to overcome the blood shortage during pandemics was the organization of mobile blood drives at donors’ homes, work, and educational sites. Statically significant associations were found between blood donation during this pandemic and age (p=0.019) and marital status (p=0.001).

Conclusion

The findings of this study highlight the main problems of blood transfusion due to the onset of COVID-19. Hence, the data could be a source of improving blood transfusion and blood donation systems by healthcare centers and on an individual basis. Healthcare professionals use this public management system in hospitals to minimize the adverse effects of the pandemic.

Point your SmartPhone at the code above. If you have a QR code reader the video abstract will appear. Or use:

https://youtu.be/K89bLDL2t3A

Risk of ABO-Incompatible Plasma From Non-ABO-Identical Components

The last several decades have seen significant changes in the approach to resuscitation of bleeding patients. These include the adoption of ABO-incompatible plasma transfusion in the form of group A plasma and/or low titer group O whole blood for trauma patients of unknown ABO group. Studies to date have examined the impact of these practices on patient outcomes and clinical markers of hemolysis in recipients of ABO-incompatible plasma compared to those for whom the plasma is ABO-compatible. Risk for increased mortality and/or overt hemolysis appear to be low among recipients of ABO-incompatible plasma; however, nearly all of studies are retrospective and most have focused only on adult trauma patients so results may not be generalizable to other bleeding patients. Work continues to evaluate the role of various titer thresholds in decreasing hemolytic risk and opportunities remain to improve our understanding of anti-A and anti-B antibody interactions with complement/endothelium and identify strategies to minimize risk.

Transfusion practices for pediatric oncology and hematopoietic stem cell transplantation patients: Data from the National Heart Lung and Blood Institute Recipient Epidemiology and Donor Evaluation Study-III (REDS-III)

BACKGROUND

To evaluate transfusion practices in pediatric oncology and hematopoietic stem cell transplant (HSCT) patients.

STUDY DESIGN AND METHODS

This is a multicenter retrospective study of children with oncologic diagnoses treated from 2013 to 2016 at hospitals participating in the National Heart Lung and Blood Institute Recipient Epidemiology and Donor Evaluation Study-III. Transfusion practices were evaluated by diagnosis codes and pre-transfusion laboratory values.

RESULTS

A total of 4766 inpatient encounters of oncology and HSCT patients were evaluated, with 39.3% (95% confidence interval [CI]: 37.9%-40.7%) involving a transfusion. Red blood cells (RBCs) were the most commonly transfused component (32.4%; 95% CI: 31.1%-33.8%), followed by platelets (22.7%; 95% CI: 21.5%-23.9%). Patients in the 1 to <6 years of range were most likely to be transfused and HSCT, acute myeloid leukemia, and aplastic anemia were the diagnoses most often associated with transfusion. The median hemoglobin (Hb) prior to RBC transfusion was 7.5 g/dl (10-90th percentile: 6.4-8.8 g/dl), with 45.7% of transfusions being given at 7 to <8 g/dl. The median platelet count prior to platelet transfusion was 20 × 10⁹ /L (10-90th percentile: 8-51 × 10⁹ /L), and 37.9% of transfusions were given at platelet count of >20-50 × 10⁹ /L. The median international normalized ratio (INR) prior to plasma transfusion was 1.7 (10-90th percentile: 1.3-2.7), and 36.3% of plasma transfusions were given at an INR between 1.4 and 1.7.

DISCUSSION

Transfusion of blood components is common in hospitalized pediatric oncology/HSCT patients. Relatively high pre-transfusion Hb and platelet values and relatively low INR values prior to transfusion across the studied diagnoses highlight the need for additional studies in this population.

Platelet transfusion practice and related transfusion reactions in a large teaching hospital

BACKGROUND

Platelet transfusion practice varies widely since many aspects of platelet concentrate (PC) use have not been definitively determined. The objectives of this retrospective study were to present platelet transfusion practice and evaluate PC and patient characteristics, as well as their association with transfusion reaction (TR) rate.

MATERIAL AND METHODS

Platelet transfusions over a 5-year period were analysed regarding PC characteristics (the ABO and RhD compatibility, product type, and storage duration), patient characteristics (most responsible diagnosis, age, and gender), and TR type.

RESULTS

A total of 46,351 PCs were transfused: 76.4% whole blood-derived (WBD) and 23.6% single donor apheresis (SDA). Three thousand seven hundred seventy-six patients received platelet transfusions: 24.7% paediatric and 75.3% adult patients, 79.6% outpatients and 20.4% inpatients. As much as 63.1% of all transfused PCs were fresh (stored for≤3 days), 98.0% ABO-identical, and 87.3% of all PCs given to RhD- patients were RhD-. PCs were mainly transfused to haemato-oncology (76.8%) and cardiovascular surgery patients (6.5%). Overall, 84 (0.18%) TRs were reported, with allergic TRs (ATRs) being the most common. Although PC ABO compatibility and storage duration, as well as patient age and gender, showed differences in TR rate, only the use of PCs in platelet additive solution (PAS) showed a statistically significant reduction of TRs (P<0.001).

CONCLUSION

Transfusion practice at the University Hospital Centre Zagreb resulted in almost all patients receiving ABO and RhD identical PCs, and most of them were fresh PCs. The most important factor affecting the incidence of TRs was platelet storage solution. The use of PAS effectively reduced the rate of TRs, particularly allergic TRs.

Variation in Neonatal Transfusion Practice

OBJECTIVE

To estimate the incidence of blood product transfusion, including red blood cells, platelets, and plasma, and characterize pretransfusion hematologic values for infants during their initial hospitalization after birth.

STUDY DESIGN

Retrospective cohort study using data from 7 geographically diverse US academic and community hospitals that participated in the National Heart Lung and Blood Institute Recipient Epidemiology and Donor Evaluation Study-III (REDS-III) from 2013 to 2016. Pretransfusion hematologic values were evaluated closest to each transfusion and no more than 24 hours beforehand.

RESULTS

Data from 60 243 infants were evaluated. The incidence of any transfusion differed by gestational age (P < .0001), with 80% (95% CI 76%-84%) transfused at <27 weeks of gestation (n = 329) and 0.5% (95% CI 0.5%-0.6%) transfused at ≥37 weeks of gestation (n = 53 919). The median pretransfusion hemoglobin was 11.2 g/dL (10th-90th percentile 8.8-14.1) for the entire cohort, ranging from 10.5 g/dL (8.8-12.3) for infants born extremely preterm at <27 weeks of gestation to 13.0 g/dL (10.5-15.5) for infants born at term. The median pretransfusion platelet count (×10⁹/L) was 71 (10th-90th percentile 26-135) for the entire cohort, and was >45 for all gestational age groups examined. The median pretransfusion international normalized ratio for the entire cohort was 1.7 (10th-90th percentile 1.2-2.8).

CONCLUSIONS

There is wide variability in pretransfusion hemoglobin, platelet count, and international normalized ratio values for neonatal transfusions. Our findings suggest that a large proportion of neonatal transfusions in the US are administered at thresholds greater than supported by the best-available evidence and highlight an opportunity for improved patient blood management.

A survey of US hospitals on platelet inventory management, transfusion practice, and platelet availability

BACKGROUND

A survey of US hospitals was conducted to increase our understanding of the current state of platelet (PLT) practice and supply. The survey captures information on transfusion practice and inventory management, including stock levels, outdate rates, ability to return or transfer PLTs, and low dose PLTs. Notably, the survey also elucidates PLT availability challenges and impact to patient care.

STUDY DESIGN AND METHODS

A 27 question online survey was distributed directly to over 995 US hospitals and indirectly through blood centers to many more between September 27 and October 25, 2019. Descriptive statistics were used for respondent characteristics. Bivariate analysis was performed and correlation coefficients, chi square tests, and p values determined statistical significance of relationships between variables.

RESULTS

Four hundred and eighty-one hospitals completed the survey of which 21.6%, 53.2%, and 25.2% were characterized as small, medium, and large hospitals, respectively. Some key observations from this survey include: (1) there is an opportunity for greater adherence to evidence-based guidelines; (2) higher outdate rates occur in hospitals stocking less than five PLTs and the ability to return or transfer PLTs lowers outdates; (3) use of low dose apheresis PLTs varies; and (4) decreased PLT availability is commonly reported, especially in hospitals with high usage, and can lead to delays in transfusions or surgeries.

CONCLUSION

This survey represents a comprehensive national assessment of inventory management practices and PLT availability challenges in US hospitals. Findings from this survey can be used to guide further research, help shape future guidance for industry, and assist with policy decisions.

Transfusion practices in a large cohort of hospitalized children

BACKGROUND

While previous studies have described the use of blood components in subsets of children, such as the critically ill, little is known about transfusion practices in hospitalized children across all departments and diagnostic categories. We sought to describe the utilization of red blood cell, platelet, plasma, and cryoprecipitate transfusions across hospital settings and diagnostic categories in a large cohort of hospitalized children.

STUDY DESIGN AND METHODS

The public datasets from 11 US academic and community hospitals that participated in the National Heart Lung and Blood Institute Recipient Epidemiology and Donor Evaluation Study-III (REDS-III) were accessed. All nonbirth inpatient encounters of children 0-18 years of age from 2013 to 2016 were included.

RESULTS

61,770 inpatient encounters from 41,943 unique patients were analyzed. Nine percent of encounters involved the transfusion of at least one blood component. RBC transfusions were most common (7.5%), followed by platelets (3.9%), plasma (2.5%), and cryoprecipitate (0.9%). Children undergoing cardiopulmonary bypass were most likely to be transfused. For the entire cohort, the median (interquartile range) pretransfusion laboratory values were as follows: hemoglobin, 7.9 g/dl (7.1-10.4 g/dl); platelet count, 27 × 10⁹ cells/L (14-54 × 10⁹ cells/L); and international normalized ratio was 1.6 (1.4-2.0). Recipient age differences were observed in the frequency of RBC irradiation (95% in infants, 67% in children, p < .001) and storage duration of RBC transfusions (median storage duration of 12 [8-17] days in infants and 20 [12-29] days in children, p < .001).

CONCLUSION

Based on a cohort of patients from 2013 to 2016, the transfusion of blood components is relatively common in the care of hospitalized children. The frequency of transfusion across all pediatric hospital settings, especially in children undergoing cardiopulmonary bypass, highlights the opportunities for the development of institutional transfusion guidelines and patient blood management initiatives.

Cryopreservation of platelets treated with riboflavin and UV light and stored at -80°C for 1 year

BACKGROUND

The combination of pathogen reduction technologies (PRTs) and cryopreservation can contribute to building a safe and durable platelet (PLT) inventory. Information about cryopreserved riboflavin and UV light-treated PLTs is scarce.

STUDY DESIGN AND METHODS

Twenty-four buffy coat (BC) PLT concentrates were grouped into 12 type-matched pairs, pooled, and divided into 12 non-PRT-treated control units and 12 riboflavin and UV light PRT-treated test units. Both were cryopreserved with 5% DMSO and stored at -80°C for 1 year. The cryopreservation method used was designed to avoid the formation of aggregates. PLT variables (PLT recovery, swirling, pH, MPV, and LDH) and hemostatic function measured by thromboelastography (TEG) were analyzed before cryopreservation (day 1) and post-cryopreservation at day 14 and months 3, 6, and 12 of storage at -80°C. The analyses were carried out within 1-h post-thaw.

RESULTS

No aggregates were found in either PLT group at any time. Swirling was observed in both groups. MPV increased and mean pH values decreased over time (p < .001), but the mean pH value was never below 6.4 in either group after 12 months of storage at -80°C. PLT recovery was good and clotting time became significantly shorter over the storage period in both groups (p < .001).

CONCLUSION

Our cryopreservation and thawing method prevented aggregate formation in cryopreserved riboflavin-UV-light-treated PLTs, which exhibited good recovery, swirling, pH > 6.4, and procoagulant potential, as evidenced by a reduced clotting time after 12 months of storage at -80°C. The clinical relevance of these findings should be further investigated in clinical trials.

Quality of evidence-based guidelines for platelet transfusion and use: A systematic review

BACKGROUND

Guidelines for platelet (PLT) transfusion are an important source of information for clinicians. Although guidelines intend to increase consistency and quality of care, variation in methodology and recommendations may exist that could impact the value of a guideline. We aimed to determine the quality of existing PLT transfusion guidelines using the Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument and to describe the inconsistencies in recommendations.

STUDY DESIGN AND METHODS

A systematic search was undertaken for evidence-based guidelines from January 1, 2013, to January 25, 2019. Citations were reviewed in duplicate for inclusion and descriptive data extracted. Four physicians appraised the guideline using the AGREE II instrument and the scaled score for each item evaluated was calculated. The protocol was registered in PROSPERO.

RESULTS

Of 6744 citations, 6740 records were screened. Seven of 28 full-text studies met the inclusion criteria. The median scaled score (and the interquartile range of the scaled score) for the following items were as follows: scope and purpose, 94% (8%); stakeholder involvement, 63% (18%); rigor of development, 83% (14%); clarity of presentation, 94% (6%); applicability, 58% (20%); and editorial independence, 77% (4%). Overall quality ranged from 4 to 7 (7 is the maximum score). Inconsistent recommendations were on prophylactic PLT transfusion in hypoproliferative thrombocytopenia in the presence of risk factors and dose recommendations.

CONCLUSION

Inconsistencies between guidelines and variable quality highlight areas for future guideline writers to address. Areas of specific attention include issues of stakeholder involvement and applicability.

Does ABO and RhD matching matter for platelet transfusion?

Platelets express ABO antigens and are collected in plasma, which contains ABO antibodies as would be consistent with the donor ABO group. Platelet ABO antigens that are incompatible with recipient ABO antibodies may have accelerated clearance from circulation and result in lower count increments. ABO antibodies that are passively transferred from donor plasma may result in hemolysis of recipient red blood cells. Although platelets do not express Rh antigens, they contain small numbers of intact red blood cells or fragments, which can lead to alloimmunization in the recipient. Alloimmunization to the RhD antigen may occur when platelets obtained from RhD-positive donors are transfused to RhD-negative recipients. All of these compatibility considerations must be balanced against the available supply, which may be limited due to the 5- to 7-day shelf life of platelets. This articles describes considerations for platelet ABO and RhD selection for platelet transfusions, including the impact of major ABO incompatibility on count increments, the risks of hemolysis associated with minor ABO incompatibility, and the risk of RhD alloimmunization when RhD-negative patients receive platelets obtained from RhD-positive donors.

How well do platelets prevent bleeding?

Prophylactic platelet transfusions are used to reduce the risk of spontaneous bleeding in patients with treatment- or disease-related severe thrombocytopenia. A prophylactic platelet-transfusion threshold of <10 × 103/µL has been shown to be safe in stable hematology/oncology patients. A higher threshold and/or larger or more frequent platelet doses may be appropriate for patients with clinical features associated with an increased risk of bleeding such as high fevers, sepsis, disseminated intravascular coagulation, anticoagulation therapy, or splenomegaly. Unique factors in the outpatient setting may support the use of a higher platelet-transfusion threshold and/or dose of platelets. A prophylactic platelet-transfusion strategy has been shown to be associated with a lower risk of bleeding compared with no prophylaxis in adult patients receiving chemotherapy but not for autologous transplant recipients. Despite the use of prophylactic platelet transfusions, a high incidence (50% to 70%) of spontaneous bleeding remains. Using a higher threshold or larger doses of platelets does not change this risk. New approaches to reduce the risk of spontaneous bleeding, including antifibrinolytic therapy, are currently under study.

Transfusion in critical care: Past, present and future

Anaemia and coagulopathy are common in critically ill patients and are associated with poor outcomes, including increased risk of mortality, myocardial infarction, failure to be liberated from mechanical ventilation and poor physical recovery. Transfusion of blood and blood products remains the corner stone of anaemia and coagulopathy treatment in critical care. However, determining when the benefits of transfusion outweigh the risks of anaemia may be challenging in some critically ill patients. Therefore, the European Society of Intensive Care Medicine prioritised the development of a clinical practice guideline to address anaemia and coagulopathy in non-bleeding critically ill patients. The aims of this article are to: (1) review the evolution of transfusion practice in critical care and the direction for future developments in this important area of transfusion medicine and (2) to provide a brief synopsis of the guideline development process and recommendations in a format designed for busy clinicians and blood bank staff. These clinical practice guidelines provide recommendations to clinicians on how best to manage non-bleeding critically ill patients at the bedside. More research is needed on alternative transfusion targets, use of transfusions in special populations (e.g., acute neurological injury, acute coronary syndromes), use of anaemia prevention strategies and point-of-care interventions to guide transfusion strategies.

The current state of the platelet supply in the US and proposed options to decrease the risk of critical shortages

Due to circumstances such as increased demand and an aging donor pool, the likelihood of critical platelet shortages is increasing. The platelet supply could be improved through the expansion of the donor pool, the identification and sustained utilization of high-quality donors, and changes in component processing and storage that result in a longer platelet shelf-life. Refrigerated platelets, stored at 1° to 6°C, have the potential to improve patient safety by decreasing the risk of bacterial contamination while concurrently allowing for a longer storage period (eg, 14 days) and improved hemostatic effectiveness in actively bleeding patients. An approach utilizing remuneration of apheresis platelet donors combined with pathogen reduction of the platelet components could be used as a means to increase the donor pool and identify and sustain safe, reliable, high-quality donors. Remuneration might provide an incentive for underutilized populations (eg, individuals <30 years old) to enter the apheresis platelet donor population resulting in a significant expansion of the platelet donor pool. Over time, approaches such as the use of refrigerated platelets, platelet donor remuneration, and the application of pathogen reduction technology, might serve to attract a large, reliable, and safe donor base that provides platelet collections with high yields, longer shelf-lives and, excellent hemostatic function.

Evaluating the appropriateness of platelet transfusions compared with evidence-based platelet guidelines: An audit of platelet transfusions at 57 hospitals

BACKGROUND

Platelet transfusions are used to prevent or control bleeding in patients with thrombocytopenia or platelet dysfunction. The pretransfusion platelet count threshold has been studied extensively in multiple patient settings yielding high-quality evidence that has been summarized in several comprehensive evidence-based platelet guidelines.

STUDY DESIGN AND METHODS

A prospective 12-week audit of consecutive platelet transfusions using validated and evidence-based adjudication criteria was conducted. Patient demographic, laboratory, and transfusion details were collected with an electronic audit tool. Each order was adjudicated either electronically or independently by two transfusion medicine physicians. The aim was to determine platelet transfusion appropriateness and common scenarios with deviations from guidelines.

RESULTS

Fifty-seven (38%) of 150 hospitals provided data on 1903 platelet orders, representing 90% of platelet usage in the region during the time period. Overall, 702 of 1693 adult (41.5%) and 133 of 210 pediatric orders (63.3%) were deemed inappropriate. The most common inappropriate platelet order was for prophylaxis in the absence of bleeding or planned procedure in patients with hypoproliferative thrombocytopenia and a platelet count over 10 x 10⁹ /L (53% of inappropriate orders in adults and 45% in pediatrics). Platelet transfusions ordered with either a preprinted transfusion order set (odds ratio [OR], 1.97; 95% confidence interval [CI], 1.44-2.73) or technologist prospective screening (OR, 1.40; 95% CI, 1.10-1.78) were more likely to be appropriate.

CONCLUSION

There is a discrepancy between clinical practice and evidence-based platelet guidelines. Broad educational and system changes will be needed to align platelet transfusion practice with guideline recommendations.