Use Of Platelet Transfusions Research Articles

Platelet transfusion: a clinical practice guideline from the AABB.

The AABB (formerly, the American Association of Blood Banks) developed this guideline on appropriate use of platelet transfusion in adult patients. These guidelines are based on a systematic review of randomized, clinical trials and observational studies (1900 to September 2014) that reported clinical outcomes on patients receiving prophylactic or therapeutic platelet transfusions. An expert panel reviewed the data and developed recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework. The AABB recommends that platelets should be transfused prophylactically to reduce the risk for spontaneous bleeding in hospitalized adult patients with therapy-induced hypoproliferative thrombocytopenia. The AABB recommends transfusing hospitalized adult patients with a platelet count of 10×109 cells/L or less to reduce the risk for spontaneous bleeding. The AABB recommends transfusing up to a single apheresis unit or equivalent. Greater doses are not more effective, and lower doses equal to one half of a standard apheresis unit are equally effective. (Grade: strong recommendation; moderate-quality evidence). The AABB suggests prophylactic platelet transfusion for patients having elective central venous catheter placement with a platelet count less than 20×109 cells/L. (Grade: weak recommendation; low-quality evidence). The AABB suggests prophylactic platelet transfusion for patients having elective diagnostic lumbar puncture with a platelet count less than 50×109 cells/L. (Grade: weak recommendation; very-low-quality evidence). The AABB suggests prophylactic platelet transfusion for patients having major elective nonneuraxial surgery with a platelet count less than 50×109 cells/L. (Grade: weak recommendation; very-low-quality evidence). The AABB recommends against routine prophylactic platelet transfusion for patients who are nonthrombocytopenic and have cardiac surgery with cardiopulmonary bypass. The AABB suggests platelet transfusion for patients having bypass who exhibit perioperative bleeding with thrombocytopenia and/or evidence of platelet dysfunction. (Grade: weak recommendation; very-low-quality evidence). The AABB cannot recommend for or against platelet transfusion for patients receiving antiplatelet therapy who have intracranial hemorrhage (traumatic or spontaneous). (Grade: uncertain recommendation; very-low-quality evidence).

Reversing the effects of antiplatelet agents in the setting of intracranial hemorrhage: a look at the literature.

Patients are increasingly being prescribed antiplatelet agents (APAs) for a growing number of medical and surgical conditions. These agents are associated with an increased risk of hemorrhage, including intracranial hemorrhage (ICH). In the setting of warfarin use and ICH, strategies to reverse the drug effects have improved outcomes. No such strategy exists for APAs, and these patients continue to have poor posthemorrhage outcomes. One strategy is the use of platelet transfusions to provide functional, circulating platelets. Studies have shown mixed results regarding the benefit of this practice. Other strategies include the use of desmopressin and recombinant factor VIIa. More studies are necessary to delineate the effectiveness of the various strategies.

Introduction of a Quick Assay for ADAMTS13 Activity Improved a Survival of Acquired TTP Patients Who Received Platelet Transfusions

Introduction: Daily plasma exchange (PE) has become a definitive first-line treatment for acquired thrombotic thrombocytopenic purpura (TTP). However, it remains to be controversial whether platelet transfusion is harmful or not for patients with acquired TTP during initial treatment. Some articles showed that platelet transfusion was considered as hazardous because platelet transfusion might generate widespread fresh platelet aggregates in circulation, but others reported that the mortality rate was not different between patients with and without platelet transfusion. Herein, we conducted a retrospective analysis of a large cohort of patients with acquired idiopathic TTP (ai-TTP) in Japan evaluating whether platelet transfusion was associated with unfavorable outcomes.Patients and Methods: Our laboratory has been functioning as a nationwide referral center for thrombotic microangiopathies (TMAs) in Japan. We collected a large dataset of medical information on 1211 patients with TMA from March 2000 to December 2013. Among them, 263 were ai-TTP patients with severe deficiency (<10% of normal controls) of ADAMTS13 activity (ADAMTS13:AC), with positive anti-ADAMTS13 inhibitors. These ai-TTP patients were retrospectively analyzed in detail using reported medical records that contained detailed clinical data and outcome information. ADAMTS13:AC was determined by classic von Willebrand factor multimer (VWF) assay. These results were available within 4 to 7 days in the initial period (March 2000 to March 2005, n=91). Subsequently, with use of a chromogenic ADAMTS13-act-ELISA, reporting occurred within 2 days of obtaining a plasma sample (April 2005 to December 2013, n=172). All plasma samples collected before March 2005 were re-examined by act-ELISA.Results: In 263 ai-TTP patients, 48 patients received platelet transfusions during the initial treatment and 215 did not. Factors associated with increased mortality included age greater than 60 years and presentation with central nervous system (CNS) dysfunction (p<0.05 for each), but not use of platelet transfusions [22.9% (11/48) versus 17.7% (38/215), respectively].Next, we analyzed the mortality rate in 2 groups categorized by method of ADAMTS13 activity assay. In the initial period using classic VWF assay, mortality of patients with platelet transfusion tended to be higher versus those without platelet transfusions (p=0.051, Log-rank test) as shown in Figure left (Kaplan-Meier survival curve). In contrast, in the latter period using the more rapid act-ELISA, no differences in mortality of patients with versus without platelet transfusions was noted (p=0.52, Figure right). To evaluate whether platelet transfusion is a significant hazard for patients with ai-TTP, Cox-proportional-hazards regression analysis was performed using 5 variables (age, sex, rituximab use, presence of CNS dysfunction, and platelet transfusion). Older age and use of platelet transfusion were independently associated with mortality in the initial period, and age and presence of CNS dysfunction were identified as unfavorable factors in the latter period (Table).Conclusions: Our results clearly indicated that platelet transfusion was harmful in ai-TTP patients with severe deficiency of ADAMTS13:AC before 2005 (when a quick ADAMTS13:AC assay was unavailable). After 2005 (when a quick ADAMTS13:AC assay available), the survival rate of ai-TTP patients with platelet transfusions became almost indistinguishable from those without. This result may indicate that persistent PE after platelet transfusion together with confirmation of severe ADAMTS13:AC reduces risk for aggravated platelet thrombi formation in microvasculatures of patients. However, use of platelet transfusion before PE may lead to serious thrombotic complications in heart and brain, a complication that should be avoided. [Display omitted] [Display omitted] DisclosuresMatsumoto:Alfresa Pharma Corporation: Patents & Royalties. Fujimura:Alfresa Pharma Corporation: Patents & Royalties.

Management of Cancer-Associated Venous Thromboembolism in Patients with Concomitant Thrombocytopenia: A Survey of Canadian Practitioners

INTRODUCTION: Both venous thromboembolism (VTE) and thrombocytopenia are common in cancer patients. The management of cancer-associated thrombosis (CAT) in the context of thrombocytopenia remains an important area of clinical equipoise; a paucity of evidence to support management strategies implies that guidelines and consensus statements rely on expert opinion. We aimed to characterize the practices of Canadian practitioners in the treatment of CAT in thrombocytopenic patients. METHODS: In May to July 2014, we conducted an electronic survey of Canadian practitioners likely to participate in the management of CAT. The survey was comprised mainly of open- ended questions. An estimated 300 members of the Canadian Hematology Society and Thrombosis Canada were invited to complete the survey. RESULTS: Respondents: 31 practitioners participated in the survey. 17 (55%) were board- certified hematologists, 10 (32%) were internists, and 3 (10%) were general practitioners. 14 (45%) had been in practice for &lt; 5 years, and 15 (48%) had been practicing for &gt;15 years. The majority of respondents, 27 (87%), worked in tertiary-care centers or university-affiliated institutions. 17 (55%) had self-reported expertise in thrombosis. Regarding frequency of encounters, 10 (32%) of participants reported seeing &gt; 20 patients with CAT and thrombocytopenia per year, while 8 (26%) reported seeing &lt;5 such patients per year. Management strategies: The median (IQR) platelet count above which respondents reported administering VTE prophylaxis, to patients in whom this would otherwise be indicated, was 25 (20, 30) . The median (IQR) platelet count above which respondents would administer full-dose anticoagulation for treatment of established CAT was 50 (40, 50); for reduced-dose anticoagulation, this threshold was 30 (20, 50). For patients with CAT and thrombocytopenia, 21 (68%) reported the use of sub-therapeutic doses of anticoagulation as a management strategy. A majority of respondents, 20 (65%), reported that there were cases in which they elect to withhold all anticoagulation due to thrombocytopenia in patients with acute CAT, in the absence of bleeding. 20 (65%) respondents reported using platelet transfusions to achieve a higher platelet count target than would otherwise be indicated in order to facilitate anticoagulation in patients with CAT and concomitant thrombocytopenia; the median platelet count target in such cases was 35 (30, 50). 14 of 20 respondents reporting the use of platelet transfusions for this purpose employed this transfusion strategy to facilitate full-dose anticoagulation, while a minority (n=6) administered reduced dose anticoagulation in this setting. Those who were newer to practice (&lt; 5 year in practice) and those who reported treating higher volumes of patients with CAT and thrombocytopenia (&gt;10 patients per year) were more likely to employ prophylactic platelet transfusions to facilitate the administration of anticoagulation (86% vs. 47%, p= 0.03, for newer to practice; 87% vs. 44%, p= 0.03, for those treating &gt;10 patients per year) The use of three case studies, for which participants were asked to outline a management strategy, revealed considerable variability in practice (Figure 1). CONCLUSIONS: While most respondents' practices were somewhat consistent with published consensus statements and recommendations, strategies for anticoagulation of CAT in thrombocytopenic patients were highly variable among Canadian practitioners. High quality studies are required to establish an evidence-based approach to this uncommon clinical entity. Figure 1. Initial management approach of respondents for 3 cases of CAT with thrombocytopenia. LE-DVT= lower extremity deep vein thrombosis; PE= pulmonary embolism; UE-DVT= upper-extremity deep vein thrombosis; IVC= inferior vena cava. Figure 1. Initial management approach of respondents for 3 cases of CAT with thrombocytopenia. LE-DVT= lower extremity deep vein thrombosis; PE= pulmonary embolism; UE-DVT= upper-extremity deep vein thrombosis; IVC= inferior vena cava. Disclosures Kuo: Novartis Canada: Honoraria; Alexion: Honoraria.

High Rates of Passive CMV Antibody Acquisition Pre-Allograft in Patients Receiving Plasma-Rich CMV Unselected and Leukodepleted Blood Components: A Caution for Donor Selection

▪For many years there has been ongoing debate in the United Kingdom (UK) about the necessity of using blood components from cytomegalovirus IgG seronegative (CMV neg) donors for CMV neg patients undergoing allogeneic hematopoietic stem cell transplantation, in the era of universal leukodepletion. From June 2012, our centre followed the guidance of the Advisory Committee on the Safety of Blood Tissues and Organs (SaBTO) in the United Kingdom, using CMV unselected leucodepleted components for all patients regardless of CMV serostatus. As part of an ongoing biovigilance commitment, we assessed the impact this policy had on rates of CMV seroconversion and viremia.137 patients were included in the study, each allografted between March 2012 and December 2013. The median age was 49 years (range 2-71) and 62% were male. Diseases transplanted included acute leukemia or myelodysplastic syndrome (73.0%), lymphoma (11.0%), chronic leukemias (7.3%) and others (8.7%). 42 patients (30.7%) received myeloablative conditioning, 43 (31.4%) received total body irradiation, and 112 (81.7%) received in-vivo T-cell depletion with alemtuzumab. 119 (86.9%) received peripheral blood stem cells, 8 (5.8%) bone marrow, and 10 (7.3%) cord blood. 35 donors (25.5%) were siblings. 78 patients (56.9%) were CMV neg when first documented, of which 62 (79.5%) had a CMV neg donor. 59 patients (43.1%) were CMV IgG seropositive (CMV pos) when first documented, of which 36 (64.3%) had a CMV pos donor. All patients had CMV serology checked again within 28 days pre-transplant: of the 78 CMV neg patients, 14 (17.9%) were found to have changed their CMV status to seropositive. Of note, these patients had received significantly more platelet transfusions in the three months prior to transplant than those who did not seroconvert pre-transplant (median 13 vs 0 adult doses, p<0.001, see figure). Another such patient, who had not received platelet transfusions, had received multiple doses of intravenous immunoglobulin. There was also a trend towards increased packed red cell transfusions (median 8 vs 0 adult units, p=0.087) in these patients. None of these patients subsequently showed CMV viremia (by quantitative CMV DNA polymerase chain reaction) post-transplant, supporting the notion that this apparent seroconversion was due to passive transfer of CMV IgG antibody from seropositive blood donors, although CMV IgM or CMV DNA was not tested for at the time. By contrast, the rate of CMV viremia in patients found to be CMV pos at first contact was 89.3% at 100 days, with a median time to first detected viraemia of 22 days post-transplant. No CMV viraemia was seen in the 62 CMV neg patients with a CMV neg donor. Of the 15 CMV neg patients with a CMV pos donor, four patients (26.7%) had CMV viraemia, at 24, 46, 48, and 54 days respectively.ConclusionIn 78 CMV IgG negative patients, there were only four incidences of proven primary CMV infection, all in patients receiving CMV pos stem cell donations. Excluding these cases, there were no cases of primary CMV infection associated with transfusion of CMV unselected blood components. However, we found a significant incidence of probable passive transfer of CMV IgG antibody, which was strongly associated with the use of platelet transfusions. Whilst this has no direct impact on the patient, it has significant implications for donor selection if it is incorrectly interpreted as representing prior CMV infection. It is conceivable that a CMV na•ve patient could be incorrectly ascribed as CMV positive due to detectable passive antibody: by selecting a CMV positive donor in these circumstances, the patient is thus subjected to a significant risk of primary CMV infection. Transplant centres must remain vigilant of this possibility, and be aware of the CMV selection policy for blood components in referring hospitals. Pre-transfusion CMV status should be obtained in all potential transplant candidates and, in those who appear to seroconvert, CMV IgM and DNA should be considered as indicators of recent seroconversion. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Platelet transfusion: a systematic review of the clinical evidence.

Platelet (PLT) transfusion is indicated either prophylactically or therapeutically to reduce the risk of bleeding or to control active bleeding. Significant uncertainty exists regarding the appropriate use of PLT transfusion and the optimal threshold for transfusion in various settings. We formulated 12 key questions to assess the role of PLT transfusion. We performed a systematic review (SR) of randomized controlled trials (RCTs) and observational studies. A comprehensive search of PubMed, Web of Science, and Cochrane registry of controlled trials was performed. Methodologic quality of included studies was assessed and a meta-analysis was performed if more than two studies with similar designs were identified for a specific question. Seventeen RCTs and 55 observational studies were included in the final SR. Results from RCTs showed a beneficial effect of prophylactic compared with therapeutic transfusion for the prevention of significant bleeding in patients with hematologic disorders undergoing chemotherapy or stem cell transplantation. We found no difference in significant bleeding events related to the PLT count threshold for transfusion or the dose of PLTs transfused. Overall methodologic quality of RCTs was moderate. Results from observational studies showed no evidence that PLT transfusion prevented significant bleeding in patients undergoing central venous catheter insertions, lumbar puncture, or other surgical procedures. The methodologic quality of observational studies was very low. We provide a comprehensive assessment of evidence on the use of PLT transfusions in a variety of clinical settings. Our report summarizes current knowledge and identifies gaps to be addressed in future research.

Developing nursing practice in platelet transfusions.

The number of platelet transfusions has risen steadily over the past five years. This article addresses some of the reasons for this increase and examines current transfusion practice in relation to findings of national audits of platelet use and current research. It explores the extended role of the nurse in platelet transfusions, including nurse authorisation, and presents an overview of education material available to inform practice and to ensure judicious use of platelet transfusions with maximum benefit for the patient.

PP-040 IS THE BURKITT LEUKEMIA PROGNOSIS AS GOOD AS EXPECTED?

The transfusion of platelets for both prophylaxis and treatment of bleeding is relevant to all areas of medicine and surgery. Historically, guidance regarding platelet transfusion has been limited by a lack of good quality clinical trials and so has been based largely on expert opinion. In recent years however there has been renewed interest in methods to prevent and treat hemorrhage, and the field has benefited from a number of large clinical trials. Some studies, such as platelet transfusion versus standard care after acute stroke due to spontaneous cerebral haemorrhage associated with antiplatelet therapy (PATCH) and platelets for neonatal transfusion Study 2 (PLANET-2), have reported an increased risk of harm with platelet transfusion in specific patient groups. These studies suggest a wider role of platelets beyond hemostasis, and highlight the need for further clinical trials to better understand the risks and benefits of platelet transfusions.This review evaluates the indications for platelet transfusion, both prophylactic and therapeutic, in the light of recent studies and clinical trials. It highlights new developments in the fields of platelet storage and platelet substitutes, and novel ways to avoid complications associated with platelet transfusions. Lastly, it reviews initiatives designed to reduce inappropriate use of platelet transfusions and to preserve this valuable resource for situations where there is evidence for their beneficial effect.

Alternative agents versus prophylactic platelet transfusion for preventing bleeding in patients with haematological disorders after chemotherapy or stem cell transplantation.

This is the protocol for a review and there is no abstract. The objectives are as follows: To determine whether alternative agents (e.g. artificial platelet substitutes, platelet-poor plasma, fibrinogen, rFVIIa, thrombopoietin mimetics) are as effective and safe as the use of platelet transfusions for the prevention of bleeding (prophylactic platelet transfusion) in patients with haematological disorders who are undergoing myelosuppressive chemotherapy or stem cell transplantation. Antifibrinolytics (lysine analogues) will not be included in this review because they have been the focus of another Cochrane review (Wardrop 2013).

The Use Of Platelet Transfusions In The Intensive Care Unit and Impact On Platelet Count: A 30,000 Patient Registry Study

BackgroundThrombocytopenia is a common complication of critical illness and an independent risk factor for bleeding and death in the intensive care unit (ICU). Platelet transfusions are commonly used to improve platelet counts; however, the expected platelet increment from a transfusion in this setting has not been established. The objective of this study was to describe the frequency of platelet transfusion administration and their effect on platelet count increments in a large cohort of non-oncology critically ill adults. MethodsWe performed an analysis of a registry database, which was developed to capture clinical and laboratory data on all blood transfusions administered in 3 academic hospitals in Hamilton, Ontario, Canada. We included all patients ≥18 years who received one or more platelet transfusion during an ICU admission. Data validation was done by integrity checks with medical records and laboratory information system performed by a biostatistician. Non-transfused ICU patients were used as controls. The absolute increment in platelet count was calculated for each single platelet transfusion using the closest platelet count taken within 24 hours before the transfusion and 4-24 hours after the transfusion. ResultsBetween April 2006 and October 2012, 33,222 patients were admitted to ICU, including 29,511 (88.8%) who did not have a diagnosis of cancer. Of those, 4,502 (15.3%) received one or more platelet transfusion during any ICU admission (n=4,690); 31.9% were female and median age at the time of first admission was 69 years (IQR 59-77). Among the 25,009 non-transfused patients admitted to ICU during the same period, 38.1% were female and the median age was 65 years (IQR 52–76). Median pre-transfusion platelet count was 87 x109/L (IQR 59-131) and a single platelet transfusion resulted in a median platelet count increment of 21 x109/L (IQR 6-40) as measured 6.7 hours (IQR 5.1-9.8) after the transfusion. There were 277 (25.4%) transfusions that yielded a platelet count increment of 5 x109/L or less. ICU mortality was 562/4,690 (12.4%) for patients who received a platelet transfusion, compared with 2,251/33,033(6.8%) for patients who were not transfused during their ICU stay. Summary/ConclusionAmong this large cohort of non-oncology ICU patients, platelet transfusions were commonly administered for thrombocytopenia that was generally mild. In this setting one platelet transfusion resulted in a median platelet count rise of 21 x109/L. Many transfusion episodes yielded no appreciable increase in platelet count. Further studies are needed to determine the clinical effects of platelet transfusion in this setting controlling for confounding. Disclosures:Heddle:CIHR: Research Funding; Canadian Blood Services: Membership on an entity's Board of Directors or advisory committees; Health Canada: Research Funding; Macopharma: Consultancy; ASH: Honoraria.

First Successful Use of Eltrombopag Before Surgery in a Child With MYH9-Related Thrombocytopenia

MYH9-related disease (MYH9-RD) is one of the most frequent autosomal-dominant forms of inherited macrothrombocytopenias and is caused by mutations in MYH9 (nonmuscle myosin IIA), the gene coding for the heavy chain of the nonmuscle myosin IIA. Affected individuals can present with isolated thrombocytopenia, and whereas only some will have bleeding events requiring intervention, nearly all will require the use of prophylactic platelet transfusions before surgery. Here we report the first prophylactic use of eltrombopag before surgery in a child with MYH9-RD. Our patient was a 13-year-old girl with an MYH9 S96L missense mutation who required a tympanoplasty due to chronic otitis media. Pretreatment microscopic platelet count was 10 × 10(9)/L. The child was treated with eltrombopag starting 4 weeks before her planned surgery. On the day of surgery her platelet count was 70 × 10(9)/L. She required no platelet transfusions and no abnormal bleeding was reported either during surgery or postoperatively. Given these results, the first reported in a child, we suggest that the use of this thrombopoietic agent should be further evaluated as a useful presurgical prophylactic option in this hereditary thrombocytopenia, thus avoiding the use of platelet transfusions and their associated risks, which include alloimmunization and the transmission of infectious agents.

The use of platelet transfusion in thrombocytopenic patients for phacoemulsification

Two elderly patients with histories of myelodysplastic syndrome and idiopathic thrombocytopenic purpura both suffered from blurred vision for a long time and asked for cataract surgery. Due to their extremely low platelet counts, 5000/μL and 6000/μL, respectively, we administrated 12-unit platelet transfusions each, 2 hours to the surgery. The operations were carried out smoothly, and there were no bleeding-associated complications during these operative procedures. Both patients were satisfied with their visual improvement at postoperative 1-week follow up with visual acuity of 0.8 and 1.0, respectively, and there was no adverse event reported. From these two cases, we suggested that in patients with thrombocytopenia, phacoemulsification cataract surgery can be performed with preoperative platelet transfusion, producing favorable results without any bleeding-associated complications.

Distinct differences in platelet production and function between neonates and adults: implications for platelet transfusion practice

Thrombocytopenia is a common problem among sick neonates admitted to the neonatal intensive care unit. Among neonates, preterm infants are the subgroup at highest risk for thrombocytopenia and hemorrhage, which is frequently intracranial. Although there is no evidence of a relationship between platelet (PLT) count and occurrence of major hemorrhage, preterm infants are commonly transfused prophylactically when PLT counts fall below an arbitrary limit, and this threshold is usually higher than for older infants or adults. This liberal practice has been influenced by the observation that, in vitro, neonatal PLTs are hyporeactive in response to multiple agonists. However, full-term infants exhibit normal to increased primary hemostasis due to factors in neonatal blood that enhance the PLT-vessel wall interaction. Additionally, cardiorespiratory problems are considered the main etiologic factors in the development of neonatal intraventricular hemorrhage. In this review, we will discuss the developmental differences that exist in regard to PLT production and function, as well as in primary hemostasis in preterm and term neonates, and the implications of these developmental differences to transfusion medicine. PLT transfusions are not exempt of risk, and a better understanding of the PLT function and the hemostatic profile of premature infants and their changes over time and in response to illness is the starting point to design randomized controlled trials to define optimal use of PLT transfusions in premature neonates. Without these future trials, the marked disparities in PLT transfusion practice in neonates between hospitals and countries will remain over time.

Thrombocytopenia, bleeding, and use of platelet transfusions in sick neonates

Abstract Survival rates for infants born prematurely have improved significantly, in part due to better supportive care such as RBC transfusion. The role of platelet transfusions in neonates is more controversial. Neonatal thrombocytopenia is common in premature infants. The primary causal factors are intrauterine growth restriction/maternal hypertension, in which the infant presents with thrombocytopenia soon after birth, and sepsis/necrotizing enterocolitis, which are the common morbidities associated with thrombocytopenia in neonates &gt; 72 hours of age. There is no evidence of a relationship between platelet count and occurrence of major hemorrhage, and cardiorespiratory problems are considered the main etiological factors in the development of intraventricular and periventricular hemorrhage in the neonatal period. Platelet transfusions are used commonly as prophylaxis in premature neonates with thrombocytopenia. However, there is widespread variation in the pretransfusion thresholds for platelet count and evidence of marked disparities in platelet transfusion practice between hospitals and countries. Platelet transfusions are biological agents and as such are associated with risks. Unlike other patient groups, specifically patients with hematological malignancies, there have been no recent clinical trials undertaken comparing different thresholds for platelet transfusion in premature neonates. Therefore, there is no evidence base with which to inform safe and effective practice for prophylactic platelet transfusions. There is a need for randomized controlled trials to define the optimal use of platelet transfusions in premature neonates, who at present are transfused heavily with platelets.

Thrombocytopenia, bleeding, and use of platelet transfusions in sick neonates.

Survival rates for infants born prematurely have improved significantly, in part due to better supportive care such as RBC transfusion. The role of platelet transfusions in neonates is more controversial. Neonatal thrombocytopenia is common in premature infants. The primary causal factors are intrauterine growth restriction/maternal hypertension, in which the infant presents with thrombocytopenia soon after birth, and sepsis/necrotizing enterocolitis, which are the common morbidities associated with thrombocytopenia in neonates > 72 hours of age. There is no evidence of a relationship between platelet count and occurrence of major hemorrhage, and cardiorespiratory problems are considered the main etiological factors in the development of intraventricular and periventricular hemorrhage in the neonatal period. Platelet transfusions are used commonly as prophylaxis in premature neonates with thrombocytopenia. However, there is widespread variation in the pretransfusion thresholds for platelet count and evidence of marked disparities in platelet transfusion practice between hospitals and countries. Platelet transfusions are biological agents and as such are associated with risks. Unlike other patient groups, specifically patients with hematological malignancies, there have been no recent clinical trials undertaken comparing different thresholds for platelet transfusion in premature neonates. Therefore, there is no evidence base with which to inform safe and effective practice for prophylactic platelet transfusions. There is a need for randomized controlled trials to define the optimal use of platelet transfusions in premature neonates, who at present are transfused heavily with platelets.

Thrombocytopenia and platelet transfusion in UK critical care: a multicenter observational study

Platelet (PLT) transfusions are widely used, but few studies have described patterns of use in critical care. As part of a prospective multicenter observational study of all sequentially admitted patients to UK general intensive care units (ICUs) over 8 weeks, daily data were collected throughout admission on frequency of thrombocytopenia and use of PLT transfusions, in addition to clinical outcomes, including bleeding. There were 1923 admissions recruited across 29 ICUs for analysis (96.6% of all eligible admissions). The period prevalences of severe thrombocytopenia (<50 × 10(9) /L) for the entire ICU stay were 12.4% (234/1881) and 13.7% (263/1914) when the 24 hours before admission was also included. A total of 35.4% of patients who experienced severe thrombocytopenia died in the ICU. A total of 169 patients (9% of study population) received 534 units of transfused PLTs (median number of units per patient admission was 2; interquartile range, 1-3; maximum, 38). Pretransfusion PLT counts were more than 50 × 10(9) for 40% of PLT transfusions overall, and even when no clinically significant bleeding was recorded on the day of transfusion, the lowest recorded PLT count was more than 50 × 10(9) for 34% of transfusions. There was evidence of only modest increments in PLT count. Thrombocytopenia is common in critical care, but there is wide variation in PLT transfusion use. Patients commonly received PLT transfusions on days without clinically significant hemorrhage. The high prevalence of thrombocytopenia in the critically ill population and inconsistent patterns of PLT transfusions indicate the importance of improving the evidence base for PLT use.

Platelet transfusions in haematology patients: are we using them appropriately?

A large proportion of all platelet components are given to haematology patients. As there are risks associated with their transfusion, costs associated with production, and shortages may occur, it is important that their use is appropriate. The study was split into two parts, a survey to assess local practice guidelines and an assessment of platelet usage. A total of 123 hospitals completed the survey and 168 hospitals submitted data of 40 haematology patients over a 3-month period. The organizational survey found that 36% of hospitals routinely give prophylactic platelet transfusions to patients with long-term bone-marrow failure. Also, a significant minority of hospitals administer platelet transfusions if the platelet count is below a certain threshold prior to performing a bone-marrow aspirate (11%) or a bone-marrow aspirate and trephine (23%); both of these are contrary to UK platelet transfusion guidelines. Data were collected on a total of 3402 patients, of which 3296 cases were eligible for analysis. They received approximately 46% of all platelet components issued to participating hospitals in England during the study period. The majority (69%) of platelet transfusions were prophylactic; of these only 33% were given when the platelet count was ≤10×10(9)/l. Using an algorithm, based on current UK guidelines, 60% of prophylactic transfusions were appropriate, 6% could not be assessed and 34% were inappropriate. A total of 10% of all prophylactic transfusions were double the standard adult dose. There is considerable potential for decreased use of platelet transfusions with a consequent improvement in their appropriate use and cost reduction.

Severe thrombocytopenia and patterns of bleeding in neonates: results from a prospective observational study and implications for use of platelet transfusions

To describe patterns of clinical bleeding in neonates with severe thrombocytopenia (ST and platelet count <60 × 10(9) L(-1)), and to investigate the factors related to bleeding. Seven tertiary-level neonatal units enrolled neonates (n = 169) with ST. Data were collected prospectively on all clinically apparent haemorrhages. Relationships between bleeding, platelet count and baseline characteristics were explored through regression analysis. Bleeding was recorded in most neonates with ST (138/169; 82%), including 123 neonates with minor bleeding and 15 neonates with major bleeding. The most common sites of minor bleeding were from the renal tract (haematuria 40%), endotracheal tube (21%), nasogastric tube (10%) and skin (15%). Gestational age <34 weeks, development of ST within 10 days of birth and necrotizing enterocolitis were the strongest predictors for an increased number of bleeding events. For neonates with ST, a lower platelet count was not a strong predictor of increased bleeding. The majority of neonates with ST bleed, although most episodes are minor. These findings establish the importance of clinical factors for bleeding risk, rather than minimum platelet count. Further studies should assess the clinical significance of different types of minor bleed for neonatal outcomes, the predictive value of minor bleeding for major bleeding and the role of platelet transfusions in preventing bleeding.

Utility of platelet transfusion in adult patients with traumatic intracranial hemorrhage and preinjury antiplatelet use

Preinjury use of antiplatelet agents (e.g., clopidogrel and aspirin) is a risk factor for increased morbidity and mortality for patients with traumatic intracranial hemorrhage (tICH). Some investigators have recommended platelet transfusion to reverse the antiplatelet effects in tICH. This evidence-based medicine review examines the evidence regarding the impact of platelet transfusion on emergency department (ED) patients with preinjury antiplatelet use and tICH on patient-oriented outcomes. The MEDLINE, EMBASE, Cochrane Library, and other databases were searched. Studies were selected for inclusion if they compared platelet transfusion with no-platelet transfusion in the treatment of adult ED patients with preinjury antiplatelet use and tICH and reported rates of mortality, neurocognitive function, or adverse effects. We assessed the quality of the included studies using standard criteria. Five retrospective, registry-based studies were identified, which enrolled 635 patients cumulatively. Based on standard criteria, three studies were of low-quality evidence, and two studies were of very low-quality evidence. One study reported higher in-hospital mortality for patients with platelet transfusion (relative risk, 2.42; 95% confidence interval, 1.2-4.9); another showed a lower mortality rate for patients receiving platelet transfusion (relative risk, 0.21; 95% confidence interval, 0.05-0.95). Three studies did not show any statistical difference in comparing mortality rates between the groups. No studies reported intermediate or long-term neurocognitive outcomes or adverse events. Five retrospective registry studies with suboptimal methodologies provide inadequate evidence to support the routine use of platelet transfusion in adult ED patients with preinjury antiplatelet use and tICH. Systematic review, level III.

Prophylactic platelet transfusion for prevention of bleeding in patients with haematological disorders after chemotherapy and stem cell transplantation

Prophylactic platelet transfusion for prevention of bleeding in patients with haematological disorders after chemotherapy and stem cell transplantation