Safety of stringent prophylactic platelet transfusion policy for patients with acute leukaemia

Thrombocytopenia in the intensive care unit: diagnosis and management

BACKGROUND

This narrative review aims to describe the epidemiology and aetiologies of thrombocytopenia in critically ill patients, the bleeding risk assessment in thrombocytopenic patients, and provide an update on platelet transfusion indications.

RESULTS

Thrombocytopenia is a common disorder in critically ill patients. The classic definition relies on an absolute platelet count below 150 × 109/L. Alternatively, the definition has extended to a relative decrease in platelet count (typically within a range of >30->50% decrease) from baseline, yet remaining above 150 × 109/L. Thrombocytopenia may result from multiple mechanisms depending upon the underlying conditions and the current clinical setting. Regardless of the causes, thrombocytopenia accounts as an independent determinant of poor outcomes in critically ill patients, albeit often of unclear interpretation. Nevertheless, it is well established that thrombocytopenia is associated with an increased incidence of bleeding complications. However, alternative factors also contribute to the risk of bleeding, making it difficult to establish definite links between nadir platelet counts at the expense of potential adverse events. Platelet transfusion represents the primary supportive treatment of thrombocytopenia to prevent or treat bleeding. As randomised controlled trials comparing different platelet count thresholds for prophylactic platelet transfusion in the ICU are lacking, the prophylactic transfusion strategy is largely derived from studies performed in stable haematology patients. Similarly, the platelet count transfusion threshold to secure invasive procedures remains based on a low level of evidence. Indications of platelet transfusions for the treatment of severe bleeding in thrombocytopenic patients remain largely empirical, with platelet count thresholds ranging from 50 to 100 × 109/L. In addition, early and aggressive platelet transfusion is part of massive transfusion protocols in the setting of severe trauma-related haemorrhage.

CONCLUSION

Thrombocytopenia in critically ill patients is very frequent with various etiologies, and is associated with worsened prognosis, with or without bleeding complications. Interventional trials focused on critically ill patients are eagerly needed to better delineate the benefits and harms of platelet transfusions.

Intracranial hemorrhage in newly diagnosed non-promyelocytic acute myeloid leukemia patients admitted for intensive induction chemotherapy

OBJECTIVES AND METHODS

Intracranial hemorrhage (ICH) in acute myeloid leukemia (AML) patients is a major concern due to the increased risk of mortality. Few studies have examined ICH specifically in newly diagnosed AML patients receiving intensive induction chemotherapy (IC) and prophylactic platelet transfusions during thrombocytopenia <10/nL. This retrospective cohort study included 423 newly diagnosed AML patients without acute promyelocytic leukemia who underwent IC between 2007 and 2019. We assessed risk factors, clinical features, and outcomes of ICH.

RESULTS

17 of 423 patients (4%) suffered ICH during hospital stay, and 4 patients (24%) died directly because of ICH despite routine prophylactic platelet transfusions. Patients with ICH had a negatively impacted overall survival (median OS, 20.1 vs. 104.8 months) and were more likely not to continue with curative treatment. Main risk factors were female gender, severe thrombocytopenia, and decreased fibrinogen. Patients with subsequent ICH also had laboratory signs of liver dysfunction.

CONCLUSIONS

Intracranial hemorrhage remains a potentially deadly complication with notable incidence despite prophylactic platelet substitution, suggesting that additional prophylactic interventions may be required to further reduce the frequency of ICH in high-risk patients. Unrecognized genetic factors may simultaneously predispose to AML and platelet dysfunction with ICH.

Safety of bone marrow aspiration and biopsy in severely thrombocytopenic patients

PURPOSE

To assess the safety of fluoroscopically guided drill-assisted bone marrow aspirate and biopsy in severely thrombocytopenic patients.

MATERIALS AND METHODS

The study was approved by the IRB with waiver of informed consent. Retrospective review of 111 bone marrow aspirate and biopsies (BMAB) performed in 94 patients who received a CT scan which included the pelvis and biopsy site within the 7 days following the BMAB. The 94 patients were subdivided based on their platelet count: severe thrombocytopenia (< 20 platelets × 10⁹/L), thrombocytopenia (20-50 platelets × 10⁹/L), and control (> 50 platelets × 10⁹/L). The procedure report was reviewed for sedation time, aspirate volume, and aggregate size of core biopsy specimens. The electronic medical record was reviewed for specimen adequacy; pathologic diagnosis; body mass index; pre- and post-procedure labs including platelet count, hemoglobin (HGB), hematocrit (HCT), prothrombin time (PT), and international normalized ratio (INR) levels; post-procedural transfusion; and complications including mortality at 30 and 90 days. CT scans were independently reviewed by 2 fellowship-trained radiologists for the presence of post-procedural hemorrhage.

RESULTS

There was no significant difference in CT-identified post-procedural hematoma, or change in the hemoglobin and hematocrit levels pre- and post-procedure between the three groups. There was no significant difference in complication rate or all-cause mortality. There was a significant difference in transfusion at 30 days with thrombocytopenic and severely thrombocytopenic patients more likely to receive transfusion within the 30 days post-procedure.

CONCLUSION

Fluoroscopically guided BMAB can be safely performed in patients with severe thrombocytopenia.

Ex Vivo Manufacture of Megakaryocytes and Platelets from Stem Cells: Recent Advances Toward Transfusion in Humans

The generation of ex vivo functional megakaryocytes (MK) and platelets is an important issue in transfusion medicine as donor dependence implies in limitations, such as shortage of eligible volunteers. Indeed, platelet transfusion is still a procedure that saves the lives of patients with defective platelet production. Recent technological development has enabled the isolation and expansion of stem cells that can be used as a source for the production of functional platelets for transfusion. In this review, we discuss recent approaches of in vitro or ex vivo production of MK and platelets, suggesting that, in the near future, donor-independent sources may become a possibility. The feasibility of using these cells in the clinic may be safer, and in vitro manipulation could generate universally compatible products, solving problems related to platelet refractoriness. However, functionality and survival testing of these products in human beings are scarce; therefore, additional studies are needed to consolidate this purpose.

Clinical efficacy of platelet transfusion therapy in patients with leukemia and analysis of risk factors for ineffective transfusion

Clinical efficacy of platelet transfusion therapy in patients with leukemia was investigated to analyze risk factors for ineffective transfusion. A total of 105 cases of patients with leukemia admitted to The First Affiliated Hospital of Bengbu Medical College from August 2016 to November 2018 were selected as research subjects. A total of 49 patients received transfusion of apheresis platelet suspension, and were group A. Fifty-six patients who received mixed multi-person platelet suspension were group B. The percentage plate recovery (PPR) and corrected count increment (CCI), interleukin-11 (IL-11) and soluble glycoprotein 130 (sgp130) levels were compared between the two groups, and the correlation of PPR and CCI with serum IL-11 and sgp130 levels was analyzed. Multivariate logistic regression was used to analyze the independent risk factors affecting ineffective transfusion in patients with leukemia. After transfusion, PPR and CCI in both groups were significantly higher than those before transfusion (P<0.05). IL-11 was significantly increased in both groups after transfusion, and sgp130 was significantly decreased in the two groups after transfusion (P<0.05). Serum IL-11 level in leukemia patients was positively correlated with PPR and CCI (r=0.7693, P<0.001), (r=0.7760, P<0.001), and serum sgp130 level in leukemia patients was negatively correlated with PPR and CCI (r=-0.7086, P<0.001), (r=-0.7733, P<0.001). There were differences between the effective group and the ineffective group in transfusion frequency, fever, infection and splenomegaly (P<0.05). Fever (OR, 0.382; 95% CI, 0.183-0.972) and infection (OR, 0.367; 95% CI, 0.140-0.956) were independent risk factors for ineffective transfusion. In conclusion, apheresis platelet or mixed multi-person platelet suspension transfusion can significantly improve the disorder of platelet count in patients with leukemia, and improve the clinical efficacy. Fever and infection are independent risk factors leading to ineffective transfusion.

Incidence of Bleeding Complications With Flexible Bronchoscopy in Cancer Patients With Thrombocytopenia

BACKGROUND

Bronchoscopy is a safe procedure, but current guidelines recommend transfusion for platelets <20 K/μL. Studies of bronchoscopy in thrombocytopenia are limited.

OBJECTIVES

Our objective was to evaluate the incidence of bleeding with flexible bronchoscopy in those with thrombocytopenia especially those <20 K/μL.

METHOD

We performed a retrospective review of all flexible bronchoscopies between June 1, 2008 and December 31, 2010. Biopsies and therapeutic procedures were excluded. The χ, Fisher exact, and Rank-sum test were conducted to evaluate associations of clinically significant bleeding.

RESULTS

There were 1711 patients who underwent 2053 flexible bronchoscopies. Cancer diagnosis included hematologic (61.3%) and solid organ malignancy (34.9%). Half of the bronchoscopies had moderate to severe thrombocytopenia (<100 K/μL) with the following ranges: 14.7% with 50 to <100 K/μL, 20.6% with 20 to <50 K/μL, 10.6% with 10 to <20 K/μL, 4.1% with <10 K/μL. Platelet transfusion was given in 90.6% of those with platelets <10 K/μL and 55.5% of those with platelets 10 to <20 K/μL. The nasal route for bronchoscopy was used in 92.4%. Bleeding complication rate however was 1.1% (0.2% major) and not affected by platelets.

CONCLUSION

Bronchoscopy with lavage can be safely performed without platelet transfusion in those with platelets of ≥10 K/μL. In the absence of nasal bleeding, trauma, or deformity, the nasal route can be used for bronchoscopy.

Hematopoietic Stem Cell Transplantation Without the Use of Blood Components by the Patient's Choice: Experience of 2 Brazilian Centers

Hematopoietic stem cell transplantation (HSCT) has been used to treat many malignant and nonmalignant hematologic conditions; however, the use of HSCT in patients who refuse blood transfusions has rarely been described in the literature, and no data have been published concerning haploidentical HSCT without the use of blood products. The aim of this study is to describe the experience of a Brazilian group in performing 21 HSCTs without the use of blood components in the first 100 days after transplantation, which is the period corresponding to the greatest risk of toxicity for this procedure. We developed 21 HSCTs without transfusion support in 19 patients admitted to 2 Brazilian transplantation centers. The patients were subjected to stem cell mobilization and different conditioning regimens. No mortality related to the procedure occurred among the transplant recipients. The global survival rate after 100 days, which is the period related to the immediate toxicity of HSCT, was 94.7%, and the median duration of follow-up was 980 days, with an overall survival rate of 68.4%. Thus, refusal of blood transfusion is not an absolute contraindication for HSCT. This therapy is feasible in specific situations when the patient clearly expresses a desire to avoid blood transfusions and when favorable clinical conditions are achievable with strict, specialized medical monitoring.

Platelet Transfusions in Advanced Hematological Malignancies: A Position Paper

Treatment of patients with advanced-stage hematological malignancies (HM) includes frequent transfusions. Given present limited hospital budgets, administrative pressure is increasing on hematology services to limit the cost of these transfusions. An expert multidisciplinary panel involved in hematology formed a working party to draw up a series of proposals, including definitions of advanced stage disease and the indications for platelet transfusion. Their proposals included: (a) Platelet transfusions are indicated for the treatment of bleeding caused by low platelet counts; (b) Patients should receive full information, including the basic criteria for platelet transfusion; (c) Doctors should be trained to assess whether or not platelet transfusions are urgently required; and (d) The practice of home transfusions should be encouraged.

Storage-induced change in platelet transfusion response evaluated by serial transfusions from one donor to one patient

BACKGROUND

Storage of platelet concentrates (PCs) results in storage lesions with possible detrimental effects on platelet recovery after transfusion, which might affect their ability to prevent or arrest bleeding. The aim of this study was to compare the quality of PCs stored for 1 to 3 or 5 to 7 days by assessing the corrected count increment (CCI) after transfusion. To isolate the effects of storage time, we studied serial transfusions of PCs obtained from one donor and one donation, and transfused to one single recipient after storage for 1 to 3 days and 5 to 7 days.

STUDY DESIGN AND METHODS

Platelets were obtained from one donor by apheresis, divided into two units (>240 × 10⁹ platelets/unit) and stored for 1 to 3 and 5 to 7 days, respectively, before transfusion. The PCs were transfused on normal indications to patients undergoing treatment at the hematology ward. Platelet count was measured before and after transfusion.

RESULTS

Thirty patients concluded the study according to the protocol. The mean storage time was 2.4 ± 0.7 and 5.7 ± 0.8 days for platelets transfused on Days 1 to 3 and 5 to 7, respectively. Storage for 5 to 7 days decreased the 1-hour transfusion response as compared to platelets stored 1 to 3 days, from a CCI of 17 ± 7 to 13 ± 5. Despite this decrease, 86% of the 5 to 7 days stored PCs resulted in a CCI above the cutoff value for a successful transfusion of 7.5, which was not significantly different to PCs stored for 1 to 3 days.

CONCLUSION

Storage of PCs for 5 to 7 days only slightly altered the transfusion response.

Comparison of a therapeutic-only versus prophylactic platelet transfusion policy for people with congenital or acquired bone marrow failure disorders

BACKGROUND

Bone marrow disorders encompass a group of diseases characterised by reduced production of red cells, white cells, and platelets, or defects in their function, or both. The most common bone marrow disorder is myelodysplastic syndrome. Thrombocytopenia, a low platelet count, commonly occurs in people with bone marrow failure. Platetet transfusions are routinely used in people with thrombocytopenia secondary to bone marrow failure disorders to treat or prevent bleeding. Myelodysplastic syndrome is currently the most common reason for receiving a platelet transfusion in some Western countries.

OBJECTIVES

To determine whether a therapeutic-only platelet transfusion policy (transfusion given when patient is bleeding) is as effective and safe as a prophylactic platelet transfusion policy (transfusion given to prevent bleeding according to a prespecified platelet threshold) in people with congenital or acquired bone marrow failure disorders.

SEARCH METHODS

We searched for randomised controlled trials (RCTs), non-RCTs, and controlled before-after studies (CBAs) in the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library 2017, Issue 9), Ovid MEDLINE (from 1946), Ovid Embase (from 1974), PubMed (e-publications only), the Transfusion Evidence Library (from 1950), and ongoing trial databases to 12 October 2017.

SELECTION CRITERIA

We included RCTs, non-RCTs, and CBAs that involved the transfusion of platelet concentrates (prepared either from individual units of whole blood or by apheresis any dose, frequency, or transfusion trigger) and given to treat or prevent bleeding among people with congenital or acquired bone marrow failure disorders.We excluded uncontrolled studies, cross-sectional studies, and case-control studies. We excluded cluster-RCTs, non-randomised cluster trials, and CBAs with fewer than two intervention sites and two control sites due to the risk of confounding. We included all people with long-term bone marrow failure disorders that require platelet transfusions, including neonates. We excluded studies of alternatives to platelet transfusion, or studies of people receiving intensive chemotherapy or a stem cell transplant.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures outlined by Cochrane. Due to the absence of evidence we were unable to report on any of the review outcomes.

MAIN RESULTS

We identified one RCT that met the inclusion criteria for this review. The study enrolled only nine adults with MDS over a three-year study duration period. The trial was terminated due to poor recruitment rate (planned recruitment 60 participants over two years). Assessment of the risk of bias was not possible for all domains. The trial was a single-centre, single-blind trial. The clinical and demographic characteristics of the participants were never disclosed. The trial outcomes relevant to this review were bleeding assessments, mortality, quality of life, and length of hospital stay, but no data were available to report on any of these outcomes.We identified no completed non-RCTs or CBAs.We identified no ongoing RCTs, non-RCTs, or CBAs.

AUTHORS' CONCLUSIONS

We found no evidence to determine the safety and efficacy of therapeutic platelet transfusion compared with prophylactic platelet transfusion for people with long-term bone marrow failure disorders. This review underscores the urgency of prioritising research in this area. People with bone marrow failure depend on long-term platelet transfusion support, but the only trial that assessed a therapeutic strategy was halted. There is a need for good-quality studies comparing a therapeutic platelet transfusion strategy with a prophylactic platelet transfusion strategy; such trials should include outcomes that are important to patients, such as quality of life, length of hospital admission, and risk of bleeding.

Bleeding frequency and characteristics among hematologic malignancy inpatient rehabilitation patients with severe thrombocytopenia

OBJECTIVE

To identify the frequency and characteristics of bleeding complications during acute inpatient rehabilitation of hematologic malignancy patients with severe thrombocytopenia.

DESIGN

Retrospective descriptive analysis.

SETTING

Comprehensive cancer center acute inpatient rehabilitation unit.

PARTICIPANTS

Consecutive hematologic malignancy patients with a platelet count of less than or equal to 20,000/microliter (μL) on the day of acute inpatient rehabilitation admission from 1/1/2005 through 8/31/2016.

INTERVENTIONS

Medical records were retrospectively analyzed for demographic, laboratory, and medical data. Patients were rehabilitated using the institutional exercise guidelines for thrombocytopenic patients.

MAIN OUTCOME MEASURES

Bleeding events noted in the medical record.

RESULTS

Out of 135 acute inpatient rehabilitation admissions, 133 unique patients were analyzed with a total of 851 inpatient rehabilitation days. The mean platelet count was 14,000/μL on the day of admission and 22,000/μL over the course of the rehabilitation admission. There were 252 days of inpatient rehabilitation where patients had less than 10,000/μL platelets. A total of 97 bleeding events were documented in 77/135 (57%) admissions. Of the 97 bleeding events, 72 (74%), 14 (14%), and 11 (11%) were considered to be of low, medium, and high severity, respectively. There were 4/97 (4%) bleeding events that were highly likely attributable to physical activity but only 1/4 was considered high severity. Bleeding rates were .09, .08, .17, and .37 for > 20,000, 15-20,000, 10-15,000, and < 10,000/μL mean platelet counts respectively (p = .003). Forty-four percent of patients were transferred back to the primary acute care service with infection being the most common reason for transfer.

CONCLUSIONS

This study is the first to examine exercise-related bleeding complications during acute inpatient rehabilitation in severely thrombocytopenic hematologic cancer patients. Bleeding rates increased with lower platelet counts. However, using the exercise guidelines for severely thrombocytopenic patients, the risk of severe exercise-related bleeding events was low.

My patient is thrombocytopenic! Is (s)he? Why? And what shall I do?

Solving the riddle of a thrombocytopenic patient is a difficult and fascinating task. The spectrum of possible aetiologies is wide, ranging from an in vitro artefact to severe treatment-resistant thrombocytopenic bleeding conditions, or even life-threatening prothrombotic states. Moreover, thrombocytopenia by itself does not protect from thrombosis and sometimes a patient with a low platelet count requires concomitant antithrombotic treatment as well. In order to identify and treat the cause and the effects of the thrombocytopenia, you have to put together several pieces of information, solving a unique jig-jaw puzzle.

The present work is not a textbook article about thrombocytopenia, rather a collection of differential diagnostic thoughts, treatment concepts, and some basic knowledge, that you can retrieve when facing your next thrombocytopenic patient. Enjoy reading it, but most importantly enjoy taking care of patients with a low platelet count. I bet the present work will assist you in this challenging and rewarding clinical task.

Platelet Transfusion for Patients With Cancer: American Society of Clinical Oncology Clinical Practice Guideline Update

Purpose

To provide evidence-based guidance on the use of platelet transfusion in people with cancer. This guideline updates and replaces the previous ASCO platelet transfusion guideline published initially in 2001.

Methods

ASCO convened an Expert Panel and conducted a systematic review of the medical literature published from September 1, 2014, through October 26, 2016. This review builds on two 2015 systematic reviews that were conducted by the AABB and the International Collaboration for Transfusion Medicine Guidelines. For clinical questions that were not addressed by the AABB and the International Collaboration for Transfusion Medicine Guidelines (the use of leukoreduction and platelet transfusion in solid tumors or chronic, stable severe thrombocytopenia) or that were addressed partially (invasive procedures), the ASCO search extended back to January 2000.

Results

The updated ASCO review included 24 more recent publications: three clinical practice guidelines, eight systematic reviews, and 13 observational studies.

Recommendations

The most substantial change to a previous recommendation involved platelet transfusion in the setting of hematopoietic stem-cell transplantation. Based on data from randomized controlled trials, adult patients who undergo autologous stem-cell transplantation at experienced centers may receive a platelet transfusion at the first sign of bleeding, rather than prophylactically. Prophylactic platelet transfusion at defined platelet count thresholds is still recommended for pediatric patients undergoing autologous stem-cell transplantation and for adult and pediatric patients undergoing allogeneic stem-cell transplantation. Other recommendations address platelet transfusion in patients with hematologic malignancies or solid tumors or in those who undergo invasive procedures. Guidance is also provided regarding the production of platelet products, prevention of Rh alloimmunization, and management of refractoriness to platelet transfusion ( www.asco.org/supportive-care-guidelines and www.asco.org/guidelineswiki ).

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

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

Identification of underlying and transfusion-related platelet qualitative alterations in the hemato-oncologic patient

Hemato-oncologic patients with chemotherapy-induced thrombocytopenia are one of the populations receiving platelet transfusions. The general practice with these patients is to give prophylactic platelet transfusions when platelet counts fall below 10×10⁹PLT/L. However, in more than 40% of these patients, platelet transfusion does not prevent bleeding. The reason of the low efficacy of platelet transfusion in the context of chemotherapy patients is not entirely understood. We therefore aimed at immunophenotyping the expression of platelet surface and activation markers and thrombopoietin levels from hemato-oncologic patients before and after transfusion. A more detailed follow-up was performed in three patients that underwent autologous bone marrow transplantation. As previously reported, basal platelet activation was observed in hemato-oncologic patients. Based on flow cytometry parameters, i.e. the percentage of positivity and mean fluorescence intensity (MFI) distribution, our data provide an additional interpretation of platelet acquired qualitative changes in the hemato-oncologic patient. From our results we propose: first, the underlying activation of platelets in the hemato-oncologic patient is accompanied by loss of expression of the platelet receptors that are susceptible to protease-mediated shedding; second, soon after transfusion, the newly circulating donor platelets show additional activation, which may result in subsequent platelet receptor recycling and potential accelerated clearance of these activated platelets. In conclusion, the immunophenotype of circulating platelets changes after prophylactic platelet transfusion. Next to platelet count increment, exploration of this immunophenotype might help to explain transfusion refractory bleeding in hemato-oncologic patients. Eventually this may lead to personalization and improvement of the present platelet transfusion support regime.

A comparison of liquid chromatography-tandem mass spectrometry (LC-MS/MS) and enzyme-multiplied immunoassay technique (EMIT) for the determination of the cyclosporin A concentration in whole blood from Chinese patients

Cyclosporin A (CyA) is an immunosuppressive agent widely used in clinical therapy. In the therapeutic process, the blood concentration of CyA should be monitored to avoid or prevent rejection and toxicity. The objectives of this study were to compare the correlation of liquid chromatography-tandem mass spectrometry (LC-MS/MS) and enzyme-multiplied immunoassay technique (EMIT) for the determination of the CyA concentration in human blood and to provide evidence for the rational usage of EMIT in clinical practice. Blood samples collected from 132 patients undergoing a liver or kidney transplant or patients with aplastic anemia at Qilu Hospital of Shandong University were tested using the two methods. The calibration curve was linear from 25-500 ng·mL^-1 for LC-MS/MS and from 50-450 ng·mL^-1 for EMIT. The inter- and intra-day RSDs were less than 15%. The CyA blood concentration according to EMIT was 3.5 ng·mL^-1 more than that according to LC-MS/MS. The 95% confidence interval was -10.0~16.9 ng·mL^-1. The CyA blood concentration according to the two methods did not differ significantly (p > 0.05). LC-MS/MS and EMIT were suitable methods for determining the CyA blood concentration. The two methods were closely correlated (r² = 0.969), but the CyA blood concentration according to EMIT was slightly higher than that according to LC-MS/MS. The clinical significance of this finding needs to be further evaluated.

Thrombocytopenia and Critical Care Medicine

Platelet transfusions play an important role in the treatment of critically ill patients. Like any blood component, however, there are various aspects of platelet transfusion therapy that need be considered by the intensivist. These include the proper dose and type of platelet component to infuse, as well as the route and method of administration. Methods to reduce the volume of the transfused platelets, for example, must ensure that the infused platelets will be functional and viable, posttransfusion. Treatment and diagnosis of the HLA alloimmunized recipient can pose a serious challenge to the clinician and an obstacle to adequate platelet therapy. An ICU patient for whom an adequate posttransfusion platelet increment cannot be achieved is at great risk of suffering a fatal hemorrhage. The ICU physician should be aware of the techniques used in modern transfusion practice to avoid having to deal with this complication. Adverse reactions to platelet transfusion include not only serologic ones, but those related to febrile and allergic complications, as well as infectious complications. The latter group includes diseases caused by infection with cytomegalovirus, bacteria, and a cadre of viruses including HIV and hepatitis. The clinical approach to thrombocytopenia in the ICU will be covered in some detail in an effort to review many of the conditions associated with recipient thrombocytopenia, including ITP, TTP, dilutional thrombocytopenia, DIC, surgery, HELLP syndrome, and drug-induced thrombocytopenia. Unfortunately the treatment approaches traditionally used are not always derived from evidence-based studies. This review covers many of these topics in an attempt to help physicians become better able to manage thrombocytopenia in the ICU and thus provide the best transfusion therapy for their patients.

Comparison of a therapeutic-only versus prophylactic platelet transfusion policy for people with congenital or acquired bone marrow failure disorders

This is the protocol for a review and there is no abstract. The objectives are as follows: To compare a therapeutic-only versus prophylactic platelet transfusion policy for people with myelodysplasia, inherited or acquired aplastic anaemia, and other congenital bone marrow failure disorders.

Italian daily platelet transfusion practice for haematological patients undergoing high dose chemotherapy with or without stem cell transplantation: a survey by the GIMEMA Haemostasis and Thrombosis Working Party

BACKGROUND

Following high-dose chemotherapy/bone marrow transplantation, patients are routinely, prophylactically transfused with platelet concentrates (PC) if they have a platelet count ≤10×10⁹/L or higher in the presence of risk factors for bleeding. However, whether such transfusions are necessary in clinically stable patients with no bleeding, or whether a therapeutic transfusion strategy could be sufficient and safe, is still debated.

MATERIALS AND METHODS

The GIMEMA Haemostasis and Thrombosis Working Party sent a questionnaire to Italian haematology departments to survey several aspects of daily platelet transfusion practice, such as the cut-off platelet count for transfusion, the evaluation of refractoriness and the type of PC administered.

RESULTS

The questionnaire was answered by 18 out of 31 centres (58%). A total of 23,162 PC were transfused in 2,396 patients in 2013. The vast majority of centres (95%) transfused PC according to Italian and international guidelines; only a few transfused always at platelet counts ≤20×10⁹/L. The broad agreement on platelet count cut-off for transfusion (≤10×10⁹/L) was not confirmed when the World Health Organization (WHO) bleeding score was considered: only a third of centres (33%) used transfusions as recommended when the bleeding grade was ≥2. Platelet refractoriness was poorly monitored and most centres (89%) evaluated, mostly empirically (67%), response to transfusion only 24 hours later. Thirty percent of centres transfused platelets in asymptomatic refractory patients.

DISCUSSION

Although most Italian haematology departments transfuse PC according to Italian and international guidelines, our survey shows that in routine daily practice physicians do not comply closely with the WHO recommendations on platelet transfusions and monitoring platelet refractoriness. This causes excessive platelet transfusions, with a resulting increase of costs and waste of public health resources.

Safety and efficacy of cryopreserved autologous platelet concentrates in HLA-alloimmunized patients with hematologic malignancies

BACKGROUND

Curative chemotherapy approaches in patients with malignancies and platelet (PLT) transfusion refractoriness due to alloimmunization may be hampered by the lack of suitable PLT donors. For these patients, transfusion of cryopreserved autologous PLTs is an option, but is time- and resource-consuming. We aimed at further simplifying this process.

STUDY DESIGN AND METHODS

A retrospective single-center analysis was conducted on the transfusion of cryopreserved autologous PLTs in nine female alloimmunized, PLT transfusion-refractory patients treated for acute leukemia (n = 8) and non-Hodgkin's lymphoma (n = 1). No additional processing was used before transfusion, and most notably, washing and centrifugation steps were omitted. Clinical efficacy and safety, as well as a flow cytometric assessment of structural and functional PLT changes, were analyzed.

RESULTS

A total of 40 autologous PLT concentrates were thawed at bedside and transfused a median of 32 (range, 9 to 994) days after cryopreservation. No major bleeds and no severe dimethyl sulfoxide toxicity were observed. The median PLT count increments did not differ 1 and 18 to 24 hours after transfusion and reached 6 × 10⁹ /L (interquartile range [IQR], 3 × 10⁹ -7.5 × 10⁹ /L) and 6 × 10⁹ /L (IQR, 2.5 × 10⁹ -9.5 × 10⁹ /L), respectively. Cryopreservation resulted in partial activation of one-third of the PLTs. In vitro stimulation with strong agonists induced additional full activation of cryopreserved PLTs: median, 55% (IQR, 42%-60%) after thrombin and 39% (IQR, 36%-39%) after convulxin.

CONCLUSION

The transfusion of cryopreserved autologous PLTs is feasible and safe. Despite the cryopreservation process, PLT functionality is partially maintained.

Aging of platelets stored for transfusion

A goal of platelet storage is to maintain the quality of platelets from the point of donation to the point of transfusion - to suspend the aging process. This effort is judged by clinical and laboratory measures with varying degrees of success. Recent work gives encouragement that platelets can be maintained ex vivo beyond the current 5 -7 day shelf life whilst maintaining their quality, as measured by posttransfusion recovery and survival. However, additional measures are needed to validate the development of technologies that may further reduce the aging of stored platelets, or enhance their hemostatic properties.

Comparison of different platelet count thresholds to guide administration of prophylactic platelet transfusion for preventing bleeding in people with haematological disorders after myelosuppressive chemotherapy or stem cell transplantation

BACKGROUND

Platelet transfusions are used in modern clinical practice to prevent and treat bleeding in people who are thrombocytopenic due to bone marrow failure. Although considerable advances have been made in platelet transfusion therapy in the last 40 years, some areas continue to provoke debate, especially concerning the use of prophylactic platelet transfusions for the prevention of thrombocytopenic bleeding.This is an update of a Cochrane review first published in 2004, and previously updated in 2012 that addressed four separate questions: prophylactic versus therapeutic-only platelet transfusion policy; prophylactic platelet transfusion threshold; prophylactic platelet transfusion dose; and platelet transfusions compared to alternative treatments. This review has now been split into four smaller reviews looking at these questions individually; this review compares prophylactic platelet transfusion thresholds.

OBJECTIVES

To determine whether different platelet transfusion thresholds for administration of prophylactic platelet transfusions (platelet transfusions given to prevent bleeding) affect the efficacy and safety of prophylactic platelet transfusions in preventing bleeding in people with haematological disorders undergoing myelosuppressive chemotherapy or haematopoietic stem cell transplantation (HSCT).

SEARCH METHODS

We searched for randomised controlled trials (RCTs) in the Cochrane Central Register of Controlled Trials (CENTRAL) (Cochrane Library 2015, Issue 6, 23 July 2015), MEDLINE (from 1946), Embase (from 1974), CINAHL (from 1937), the Transfusion Evidence Library (from 1950), and ongoing trial databases to 23 July 2015.

SELECTION CRITERIA

We included RCTs involving transfusions of platelet concentrates, prepared either from individual units of whole blood or by apheresis, and given to prevent bleeding in people with haematological disorders (receiving myelosuppressive chemotherapy or undergoing HSCT) that compared different thresholds for administration of prophylactic platelet transfusions (low trigger (5 x 10(9)/L); standard trigger (10 x 10(9)/L); higher trigger (20 x 10(9)/L, 30 x 10(9)/L, 50 x 10(9)/L); or alternative platelet trigger (for example platelet mass)).

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane.

MAIN RESULTS

Three trials met our predefined inclusion criteria and were included for analysis in the review (499 participants). All three trials compared a standard trigger (10 x 10(9)/L) versus a higher trigger (20 x 10(9)/L or 30 x 10(9)/L). None of the trials compared a low trigger versus a standard trigger or an alternative platelet trigger. The trials were conducted between 1991 and 2001 and enrolled participants from fairly comparable patient populations.The original review contained four trials (658 participants); in the previous update of this review we excluded one trial (159 participants) because fewer than 80% of participants had a haematological disorder. We identified no new trials in this update of the review.Overall, the methodological quality of the studies was low across different outcomes according to GRADE methodology. None of the included studies were at low risk of bias in every domain, and all the included studies had some threats to validity.Three studies reported the number of participants with at least one clinically significant bleeding episode within 30 days from the start of the study. There was no evidence of a difference in the number of participants with a clinically significant bleeding episode between the standard and higher trigger groups (three studies; 499 participants; risk ratio (RR) 1.35, 95% confidence interval (CI) 0.95 to 1.90; low-quality evidence).One study reported the number of days with a clinically significant bleeding event (adjusted for repeated measures). There was no evidence of a difference in the number of days of bleeding per participant between the standard and higher trigger groups (one study; 255 participants; relative proportion of days with World Health Organization Grade 2 or worse bleeding (RR 1.71, 95% CI 0.84 to 3.48, P = 0.162; authors' own results; low-quality evidence).Two studies reported the number of participants with severe or life-threatening bleeding. There was no evidence of any difference in the number of participants with severe or life-threatening bleeding between a standard trigger level and a higher trigger level (two studies; 421 participants; RR 0.99, 95% CI 0.52 to 1.88; low-quality evidence).Only one study reported the time to first bleeding episode. There was no evidence of any difference in the time to the first bleeding episode between a standard trigger level and a higher trigger level (one study; 255 participants; hazard ratio 1.11, 95% CI 0.64 to 1.91; low-quality evidence).Only one study reported on all-cause mortality within 30 days from the start of the study. There was no evidence of any difference in all-cause mortality between standard and higher trigger groups (one study; 255 participants; RR 1.78, 95% CI 0.83 to 3.81; low-quality evidence).Three studies reported on the number of platelet transfusions per participant. Two studies reported on the mean number of platelet transfusions per participant. There was a significant reduction in the number of platelet transfusions per participant in the standard trigger group (two studies, mean difference -2.09, 95% CI -3.20 to -0.99; low-quality evidence).One study reported on the number of transfusion reactions. There was no evidence to demonstrate any difference in transfusion reactions between the standard and higher trigger groups (one study; 79 participants; RR 0.07, 95% CI 0.00 to 1.09).None of the studies reported on quality of life.

AUTHORS' CONCLUSIONS

In people with haematological disorders who are thrombocytopenic due to myelosuppressive chemotherapy or HSCT, we found low-quality evidence that a standard trigger level (10 x 10(9)/L) is associated with no increase in the risk of bleeding when compared to a higher trigger level (20 x 10(9)/L or 30 x 10(9)/L). There was low-quality evidence that a standard trigger level is associated with a decreased number of transfusion episodes when compared to a higher trigger level (20 x 10(9)/L or 30 x 10(9)/L).Findings from this review were based on three studies and 499 participants. Without further evidence, it is reasonable to continue with the current practice of administering prophylactic platelet transfusions using the standard trigger level (10 x 10(9)/L) in the absence of other risk factors for bleeding.

Different doses of prophylactic platelet transfusion for preventing bleeding in people with haematological disorders after myelosuppressive chemotherapy or stem cell transplantation

BACKGROUND

Platelet transfusions are used in modern clinical practice to prevent and treat bleeding in people who are thrombocytopenic due to bone marrow failure. Although considerable advances have been made in platelet transfusion therapy in the last 40 years, some areas continue to provoke debate, especially concerning the use of prophylactic platelet transfusions for the prevention of thrombocytopenic bleeding.This is an update of a Cochrane review first published in 2004, and updated in 2012 that addressed four separate questions: prophylactic versus therapeutic-only platelet transfusion policy; prophylactic platelet transfusion threshold; prophylactic platelet transfusion dose; and platelet transfusions compared to alternative treatments. This review has now been split into four smaller reviews; this review compares different platelet transfusion doses.

OBJECTIVES

To determine whether different doses of prophylactic platelet transfusions (platelet transfusions given to prevent bleeding) affect their efficacy and safety in preventing bleeding in people with haematological disorders undergoing myelosuppressive chemotherapy with or without haematopoietic stem cell transplantation (HSCT).

SEARCH METHODS

We searched for randomised controlled trials in the Cochrane Central Register of Controlled Trials (CENTRAL) (Cochrane Library 2015, Issue 6), MEDLINE (from 1946), Embase (from 1974), CINAHL (from 1937), the Transfusion Evidence Library (from 1950), and ongoing trial databases to 23 July 2015.

SELECTION CRITERIA

Randomised controlled trials involving transfusions of platelet concentrates, prepared either from individual units of whole blood or by apheresis, and given to prevent bleeding in people with malignant haematological disorders or undergoing HSCT that compared different platelet component doses (low dose 1.1 x 10(11)/m(2) ± 25%, standard dose 2.2 x 10(11)/m(2) ± 25%, high dose 4.4 x 10(11)/m(2) ± 25%).

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by The Cochrane Collaboration.

MAIN RESULTS

We included seven trials (1814 participants) in this review; six were conducted during one course of treatment (chemotherapy or HSCT).Overall the methodological quality of studies was low to moderate across different outcomes according to GRADE methodology. None of the included studies were at low risk of bias in every domain, and all the included studies had some threats to validity.Five studies reported the number of participants with at least one clinically significant bleeding episode within 30 days from the start of the study. There was no difference in the number of participants with a clinically significant bleeding episode between the low-dose and standard-dose groups (four studies; 1170 participants; risk ratio (RR) 1.04, 95% confidence interval (CI) 0.95 to 1.13; moderate-quality evidence); low-dose and high-dose groups (one study; 849 participants; RR 1.02, 95% CI 0.93 to 1.11; moderate-quality evidence); or high-dose and standard-dose groups (two studies; 951 participants; RR 1.02, 95% CI 0.93 to 1.11; moderate-quality evidence).Three studies reported the number of days with a clinically significant bleeding event per participant. There was no difference in the number of days of bleeding per participant between the low-dose and standard-dose groups (two studies; 230 participants; mean difference -0.17, 95% CI -0.51 to 0.17; low quality evidence). One study (855 participants) showed no difference in the number of days of bleeding per participant between high-dose and standard-dose groups, or between low-dose and high-dose groups (849 participants).Three studies reported the number of participants with severe or life-threatening bleeding. There was no difference in the number of participants with severe or life-threatening bleeding between a low-dose and a standard-dose platelet transfusion policy (three studies; 1059 participants; RR 1.33, 95% CI 0.91 to 1.92; low-quality evidence); low-dose and high-dose groups (one study; 849 participants; RR 1.20, 95% CI 0.82 to 1.77; low-quality evidence); or high-dose and standard-dose groups (one study; 855 participants; RR 1.11, 95% CI 0.73 to 1.68; low-quality evidence).Two studies reported the time to first bleeding episodes; we were unable to perform a meta-analysis. Both studies (959 participants) individually found that the time to first bleeding episode was either the same, or longer, in the low-dose group compared to the standard-dose group. One study (855 participants) found that the time to the first bleeding episode was the same in the high-dose group compared to the standard-dose group.Three studies reported all-cause mortality within 30 days from the start of the study. There was no difference in all-cause mortality between treatment arms (low-dose versus standard-dose: three studies; 1070 participants; RR 2.04, 95% CI 0.70 to 5.93; low-quality evidence; low-dose versus high-dose: one study; 849 participants; RR 1.33, 95% CI 0.50 to 3.54; low-quality evidence; and high-dose versus standard-dose: one study; 855 participants; RR 1.71, 95% CI 0.51 to 5.81; low-quality evidence).Six studies reported the number of platelet transfusions; we were unable to perform a meta-analysis. Two studies (959 participants) out of three (1070 participants) found that a low-dose transfusion strategy led to more transfusion episodes than a standard-dose. One study (849 participants) found that a low-dose transfusion strategy led to more transfusion episodes than a high-dose strategy. One study (855 participants) out of three (1007 participants) found no difference in the number of platelet transfusions between the high-dose and standard-dose groups.One study reported on transfusion reactions. This study's authors suggested that a high-dose platelet transfusion strategy may lead to a higher rate of transfusion-related adverse events.None of the studies reported quality-of-life.

AUTHORS' CONCLUSIONS

In haematology patients who are thrombocytopenic due to myelosuppressive chemotherapy or HSCT, we found no evidence to suggest that a low-dose platelet transfusion policy is associated with an increased bleeding risk compared to a standard-dose or high-dose policy, or that a high-dose platelet transfusion policy is associated with a decreased risk of bleeding when compared to a standard-dose policy.A low-dose platelet transfusion strategy leads to an increased number of transfusion episodes compared to a standard-dose strategy. A high-dose platelet transfusion strategy does not decrease the number of transfusion episodes per participant compared to a standard-dose regimen, and it may increase the number of transfusion-related adverse events.Findings from this review would suggest a change from current practice, with low-dose platelet transfusions used for people receiving in-patient treatment for their haematological disorder and high-dose platelet transfusion strategies not being used routinely.

A therapeutic-only versus prophylactic platelet transfusion strategy for preventing bleeding in patients with haematological disorders after myelosuppressive chemotherapy or stem cell transplantation

BACKGROUND

Platelet transfusions are used in modern clinical practice to prevent and treat bleeding in thrombocytopenic patients with bone marrow failure. Although considerable advances have been made in platelet transfusion therapy in the last 40 years, some areas continue to provoke debate, especially concerning the use of prophylactic platelet transfusions for the prevention of thrombocytopenic bleeding.This is an update of a Cochrane review first published in 2004 and updated in 2012 that addressed four separate questions: therapeutic-only versus prophylactic platelet transfusion policy; prophylactic platelet transfusion threshold; prophylactic platelet transfusion dose; and platelet transfusions compared to alternative treatments. We have now split this review into four smaller reviews looking at these questions individually; this review is the first part of the original review.

OBJECTIVES

To determine whether a therapeutic-only platelet transfusion policy (platelet transfusions given when patient bleeds) is as effective and safe as a prophylactic platelet transfusion policy (platelet transfusions given to prevent bleeding, usually when the platelet count falls below a given trigger level) in patients with haematological disorders undergoing myelosuppressive chemotherapy or stem cell transplantation.

SEARCH METHODS

We searched for randomised controlled trials (RCTs) in the Cochrane Central Register of Controlled Trials (Cochrane Library 2015, Issue 6), MEDLINE (from 1946), Embase (from 1974), CINAHL (from 1937), the Transfusion Evidence Library (from 1950) and ongoing trial databases to 23 July 2015.

SELECTION CRITERIA

RCTs involving transfusions of platelet concentrates prepared either from individual units of whole blood or by apheresis, and given to prevent or treat bleeding in patients with malignant haematological disorders receiving myelosuppressive chemotherapy or undergoing HSCT.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by The Cochrane Collaboration.

MAIN RESULTS

We identified seven RCTs that compared therapeutic platelet transfusions to prophylactic platelet transfusions in haematology patients undergoing myelosuppressive chemotherapy or HSCT. One trial is still ongoing, leaving six trials eligible with a total of 1195 participants. These trials were conducted between 1978 and 2013 and enrolled participants from fairly comparable patient populations. We were able to critically appraise five of these studies, which contained separate data for each arm, and were unable to perform quantitative analysis on one study that did not report the numbers of participants in each treatment arm.Overall the quality of evidence per outcome was low to moderate according to the GRADE approach. None of the included studies were at low risk of bias in every domain, and all the studies identified had some threats to validity. We deemed only one study to be at low risk of bias in all domains other than blinding.Two RCTs (801 participants) reported at least one bleeding episode within 30 days of the start of the study. We were unable to perform a meta-analysis due to considerable statistical heterogeneity between studies. The statistical heterogeneity seen may relate to the different methods used in studies for the assessment and grading of bleeding. The underlying patient diagnostic and treatment categories also appeared to have some effect on bleeding risk. Individually these studies showed a similar effect, that a therapeutic-only platelet transfusion strategy was associated with an increased risk of clinically significant bleeding compared with a prophylactic platelet transfusion policy. Number of days with a clinically significant bleeding event per participant was higher in the therapeutic-only group than in the prophylactic group (one RCT; 600 participants; mean difference 0.50, 95% confidence interval (CI) 0.10 to 0.90; moderate-quality evidence). There was insufficient evidence to determine whether there was any difference in the number of participants with severe or life-threatening bleeding between a therapeutic-only transfusion policy and a prophylactic platelet transfusion policy (two RCTs; 801 participants; risk ratio (RR) 4.91, 95% CI 0.86 to 28.12; low-quality evidence). Two RCTs (801 participants) reported time to first bleeding episode. As there was considerable heterogeneity between the studies, we were unable to perform a meta-analysis. Both studies individually found that time to first bleeding episode was shorter in the therapeutic-only group compared with the prophylactic platelet transfusion group.There was insufficient evidence to determine any difference in all-cause mortality within 30 days of the start of the study using a therapeutic-only platelet transfusion policy compared with a prophylactic platelet transfusion policy (two RCTs; 629 participants). Mortality was a rare event, and therefore larger studies would be needed to establish the effect of these alternative strategies. There was a clear reduction in the number of platelet transfusions per participant in the therapeutic-only arm (two RCTs, 991 participants; standardised mean reduction of 0.50 platelet transfusions per participant, 95% CI -0.63 to -0.37; moderate-quality evidence). None of the studies reported quality of life. There was no evidence of any difference in the frequency of adverse events, such as transfusion reactions, between a therapeutic-only and prophylactic platelet transfusion policy (two RCTs; 991 participants; RR 1.02, 95% CI 0.62 to 1.68), although the confidence intervals were wide.

AUTHORS' CONCLUSIONS

We found low- to moderate-grade evidence that a therapeutic-only platelet transfusion policy is associated with increased risk of bleeding when compared with a prophylactic platelet transfusion policy in haematology patients who are thrombocytopenic due to myelosuppressive chemotherapy or HSCT. There is insufficient evidence to determine any difference in mortality rates and no evidence of any difference in adverse events between a therapeutic-only platelet transfusion policy and a prophylactic platelet transfusion policy. A therapeutic-only platelet transfusion policy is associated with a clear reduction in the number of platelet components administered.

Platelet transfusion in hematology, oncology and surgery

BACKGROUND

The standard recommendation to date has been that acute hypoproliferative thrombocytopenia should be treated with a prophylactic platelet transfusion if the morning platelet count is less than 10 000/μL, or less than 20 000/μL if there are additional risk factors. For chronic thrombocytopenia, transfusion has been recommended if the platelet count is less than 5000/μL. In Germany, half a million platelet transfusions are now being given every year, and the number is rising. New studies indicate, however, that a more restrictive transfusion strategy is justified.

METHODS

A selective literature search was carried out in PubMed, with additional attention to recommendations from Germany and abroad, and to the guidelines of medical specialty societies.

RESULTS

Prophylactic platelet transfusions should be given when clinically indicated in consideration of the individual hemorrhagic risk. To prevent severe hemorrhage, it is more important to respond to the first signs of bleeding than to pay exclusive attention to morning platelet counts below 10 000/μL. This threshold value remains standard for patients with acute leukemia. According to recent studies, however, clinically stable patients who are at low risk for bleeding-e.g., patients who have undergone autologous hematopoietic stem-cell transplantation-may be well served by a therapeutic, rather than prophylactic, platelet transfusion strategy, in which platelets are transfused only when evidence of bleeding has been observed. For cancer patients, intensive-care patients, and patients with other risk factors, a clinically oriented transfusion strategy is recommended, in addition to close attention to threshold platelet values.

CONCLUSION

The number of platelet transfusions could be safely lowered by a more restrictive transfusion strategy that takes account of the risk of bleeding, as recommended in the hemotherapy guidelines.

Comparison of different platelet count thresholds to guide administration of 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 different platelet transfusion thresholds for administration of prophylactic platelet transfusions (platelet transfusions given to prevent bleeding) affect the efficacy and safety of prophylactic platelet transfusions in preventing bleeding in patients with haematological disorders after chemotherapy with or without stem cell transplantation.

Transfusion guidelines: when to transfuse

Transfusion of blood and blood components has been a routine practice for more than half a century. The rationale supporting this practice is that replacement of blood loss should be beneficial for the patient. This assumption has constituted the underpinning of transfusion medicine for many decades. Only over the past 20 years, we have seen a more concerted effort to answer very basic questions regarding the value of transfusion therapy. An assessment of the value of transfusion based on well-designed and appropriately powered randomized, controlled trials is the first step in optimizing transfusion practices. Systematic reviews provide the second step by building the knowledge base necessary to assess the impact of transfusion practice on patient outcomes. The third step is the development of clinical practice guidelines, and this occurs when systematic reviews are interpreted by individuals with expertise in transfusion medicine. Such guidelines are typically supported by professional organizations and/or health authorities. Implementation of clinical practice guidelines can be challenging, especially in an area as heterogeneous as transfusion medicine. However, clinical practice guidelines are necessary for the practice of evidence-based medicine, which optimizes patient care and improves patient outcomes. This review focuses on clinical practice guidelines for transfusion of three blood components: RBCs, platelets and plasma. In addition, we provide the approach used to implement clinical practice guidelines at our own institution.

Comparison of automated platelet counts and potential effect on transfusion decisions in cancer patients

OBJECTIVES

To evaluate the accuracy of platelet counts from various hematology analyzers using a reference immunologic method.

METHODS

We tested 403 samples with platelet counts less than 50 × 10(9)/L with the Advia (Siemens, Tarrytown, NY), Sysmex (Mundelein, IL), and Abbott (Santa Clara, CA) analyzers.

RESULTS

All methods showed a positive bias, especially at less than 20 × 10(9)/L and less than 10 × 10(9)/L. Undertransfusion risk ranged from 9.1% to 43.3 % in the groups below 20 × 10(9)/L and below 10 × 10(9)/L, respectively. For patients with optical counts more than 10 × 10(9)/L and CD61 less than 10 × 10(9)/L, 64.5% were transfused within 24 hours of the reported count, while 35.5% were transfused in more than 24 hours, after a subsequent optical platelet count of 10 × 10(9)/L or less was reported.

CONCLUSIONS

Although optical and impedance methods were shown to be falsely increased in severely thrombocytopenic samples, further studies are needed to determine if more accurate methods would be clinically useful.

Umbilical cord blood transplantation: review of factors affecting the hospitalized patient

The use of umbilical cord blood (UCB) as a stem cell donor source has dramatically increased over the last 2 decades. Patients undergoing UCB transplantation share medical management issues with patients receiving a hematopoietic stem cell transplantion using adult donor sources (peripheral blood stem cells or bone marrow stem cells) and may also have more complex medical issues that appear to be related to delayed immune recovery from UCB-derived stem cells. The interface with critical care providers is likely to occur in the transplant and posttransplant setting. Patients may experience UCB infusion reactions that range from mild to rarely severe. Following transplant, patients are transfusion dependent for long periods due to the prolonged engraftment of UCB cells. They are at high risk of infection, particularly viral. Once engrafted, UCB transplant patients have a lower rate of graft versus host disease compared to other donor sources. Some of the other complications that are seen in patients undergoing UCB transplant are posttransplant lymphoproliferative disease, diffuse alveolar hemorrhage, and posterior reversible encephalopathy will also be discussed.

The observation of bleeding complications in haemato-oncological patients: stringent watching, relevant reporting

BACKGROUND

The reported percentage of haemato-oncological patients experiencing bleeding complications is highly variable, ranging from 5 to 70%, posing a major problem for comparison of clinical platelet transfusion trials using bleeding complications as a primary endpoint. In a pilot study we assessed the impact of the design of scoring of bleeding on the percentage of patients with WHO grade 2 or higher bleeding grades.

STUDY DESIGN AND METHODS

We performed a prospective, observational study using a rigorous bleeding observation system in thrombocytopenic patients with haemato-oncological disorders. Endpoints of the study were the percentage of patients and days with bleeding WHO grade ≥ 2 comparing designs in which skin bleeding represent a continuation of a previous bleed or a new bleed.

RESULTS

In four participating hospitals 64 patients suffering 870 evaluable thrombocytopenic days (platelet count < 80 × 10(9) L(-1)) were included. At least one episode of bleeding grade ≥ 2 occurred in 36 patients (56%). Most grade 2 bleeding complications occurred mucocutaneously. The percentage of days with bleeding of grade ≥ 2 was 16% but decreases to 8% when only newly developed skin bleeding was included.

CONCLUSION

Rigorous daily observation results in a bleeding incidence that is comparable to recent reportings applying the same method. The results of this study show that censoring for stable skin bleeding has a profound effect on bleeding incidence per day. The clinical relevance of rigorous or clinically judged bleeding scores as an endpoint remains to be defined.

Platelet transfusion threshold in patients with upper gastrointestinal bleeding: a systematic review

BACKGROUND

There exists uncertainty as to the optimal platelet values when managing patients with nonvariceal upper gastrointestinal (GI) bleeding. GOALS AND STUDY: A systematic review was carried out to determine the optimal approach when managing patients with thrombocytopenia in the setting of nonvariceal upper GI bleeding.

RESULTS

Eighteen of 803 potential articles were selected and reviewed, including 4 randomized controlled trials and 6 cohort studies. The only empirical clinical data available pertained to the management of hematology or oncology patients. There was no high-level evidence that determined the proper threshold of platelet transfusion specifically in GI bleeding. We were, therefore, limited to include principally consensus opinions, recommendations, and guidelines for platelet transfusion trigger as they apply to the treatment (including prophylaxis) of bleeding in general, with a paucity of data addressing major bleeding, let alone bleeding from a gastroenterologic origin. Randomized clinical trials were individually underpowered in allowing definitive conclusions, even though resulting recommendations were supported by similarly underpowered retrospective and prospective observational studies.

CONCLUSIONS

There exist a paucity of data to recommend optimal therapeutic platelet count targets in patients with active GI bleeding. Based principally on expert opinion recommendations, we propose a count of 50×10/L. Some professional associations have suggested in very specific clinical settings (postcardiopulmonary bypass surgery or central nervous system trauma) a higher value of up to 100×10/L. Properly designed randomized trials are required to more precisely address this important clinical question.

The influence of bleeding on trigger changes for platelet transfusion in patients with chemotherapy-induced thrombocytopenia

BACKGROUND

For patients with thrombocytopenia without bleeding risk factors, a platelet transfusion trigger of 10 × 10(9) /L is recommended. No studies have evaluated the clinicians' decision-making process leading to trigger changes.

STUDY DESIGN AND METHODS

We report on the evaluation of trigger changes and the relation with bleeding. Eighty patients previously enrolled in the SPRINT trial represent the patient population for the current analysis.

RESULTS

Seventy-four patients had a starting trigger of 10 × 10(9) /L. Only a minority of patients treated with chemotherapy alone (3/12, 25%) and autologous transplant (6/15, 40%) had a change in their trigger in contrast to the majority of allogeneic transplant (37/47, 79%; p = 0.001 and p = 0.009, respectively, when compared to allogeneic transplant group). Bleeding was the main reason reported by clinicians for a trigger change, but the occurrence of significant bleeding (Grade 2-4) was similar in patients with or without a trigger change (51 and 54%, p = 1.00). Clinicians were influenced by the bleeding system: grade 1 mucocutaneous bleeding leading to a trigger change was overrepresented (71% of cases), as was grade 2 genitourinary bleeding not leading to a trigger change (57% of cases).

CONCLUSION

A universal trigger of 10 × 10(9) /L may not be maintained in a diverse population of patients with their respective bleeding risk factors. Because the trigger is changed often, it may not be as effective as previously believed.

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

BACKGROUND

Platelet transfusions are used in modern clinical practice to prevent and treat bleeding in thrombocytopenic patients with bone marrow failure. Although considerable advances have been made in platelet transfusion therapy in the last 40 years, some areas continue to provoke debate especially concerning the use of prophylactic platelet transfusions for the prevention of thrombocytopenic bleeding.

OBJECTIVES

To determine the most effective use of platelet transfusion for the prevention of bleeding in patients with haematological disorders undergoing chemotherapy or stem cell transplantation.

SEARCH METHODS

This is an update of a Cochrane review first published in 2004. We searched for randomised controlled trials (RCTs) in the Cochrane Central Register of Controlled Trials (CENTRAL Issue 4, 2011), MEDLINE (1950 to Nov 2011), EMBASE (1980 to Nov 2011) and CINAHL (1982 to Nov 2011), using adaptations of the Cochrane RCT search filter, the UKBTS/SRI Transfusion Evidence Library, and ongoing trial databases to 10 November 2011.

SELECTION CRITERIA

RCTs involving transfusions of platelet concentrates, prepared either from individual units of whole blood or by apheresis, and given to prevent bleeding in patients with haematological disorders. Four different types of prophylactic platelet transfusion trial were included.

DATA COLLECTION AND ANALYSIS

In the original review one author initially screened all electronically derived citations and abstracts of papers, identified by the review search strategy, for relevancy. Two authors performed this task in the updated review. Two authors independently assessed the full text of all potentially relevant trials for eligibility. Two authors completed data extraction independently. We requested missing data from the original investigators as appropriate.

MAIN RESULTS

There were 18 trials that were eligible for inclusion, five of these were still ongoing.Thirteen completed published trials (2331 participants) were included for analysis in the review. The original review contained nine trials (718 participants). This updated review includes six new trials (1818 participants).Two trials (205 participants) in the original review are now excluded because fewer than 80% of participants had a haematological disorder.The four different types of prophylactic platelet transfusion trial, that were the focus of this review, were included within these thirteen trials.Three trials compared prophylactic platelet transfusions versus therapeutic-only platelet transfusions. There was no statistical difference between the number of participants with clinically significant bleeding in the therapeutic and prophylactic arms but the confidence interval was wide (RR 1.66; 95% CI 0.9 to 3.04).The time taken for a clinically significant bleed to occur was longer in the prophylactic platelet transfusion arm. There was a clear reduction in platelet transfusion usage in the therapeutic arm. There was no statistical difference between the number of participants in the therapeutic and prophylactic arms with platelet refractoriness, the only adverse event reported.Three trials compared different platelet count thresholds to trigger administration of prophylactic platelet transfusions. No statistical difference was seen in the number of participants with clinically significant bleeding (RR 1.35; 95% CI 0.95 to 1.9), however, this type of bleeding occurred on fewer days in the group of patients transfused at a higher platelet count threshold (RR 1.72; 95% CI 1.33 to 2.22).The lack of a difference seen for the number of participants with clinically significant bleeding may be due to the studies, in combination, having insufficient power to demonstrate a difference, or due to masking of the effect by a higher number of protocol violations in the groups of patients with a lower platelet count threshold. Using a lower platelet count threshold led to a significant reduction in the number of platelet transfusions used. There were no statistical differences in the number of adverse events reported between the two groups.Six trials compared different doses of prophylactic platelet transfusions. There was no evidence to suggest that using a lower platelet transfusion dose increased: the number of participants with clinically significant (WHO grade 2 or above) (RR 1.02; 95% CI 0.93 to 1.11), or life-threatening (WHO grade 4) bleeding (RR 1.87; 95% CI 0.86 to 4.08). A higher platelet transfusion dose led to a reduction in the number of platelet transfusion episodes, but an increase in total platelet utilisation. Only one adverse event, wheezing after transfusion, had a significantly higher incidence when standard and high dose transfusions were compared but this difference was not seen when low dose and high dose transfusions were compared. It is therefore likely to be a type I error (false positive).One small trial compared prophylactic platelet transfusions versus platelet-poor plasma. The risk of a significant bleed was decreased in the prophylactic platelet transfusion arm (RR 0.47; 95% CI 0.23 to 0.95) and this was statistically significant.All studies had threats to validity; the majority of these were due to methodology of the studies not being described in adequate detail.Although it was not the main focus of the review, it was interesting to note that in one of the pre-specified sub-group analyses (treatment type) two studies showed that patients receiving an autologous transplant have a lower risk of bleeding than patients receiving intensive chemotherapy or an allogeneic transplant (RR 0.73, 95% CI 0.65 to 0.82).

AUTHORS' CONCLUSIONS

These conclusions refer to the four different types of platelet transfusion trial separately. Firstly, there is no evidence that a prophylactic platelet transfusion policy prevents bleeding. Two large trials comparing a therapeutic versus prophylactic platelet transfusion strategy, that have not yet been published, should provide important new data on this comparison. Secondly, there is no evidence, at the moment, to suggest a change from the current practice of using a platelet count of 10 x 10(9)/L. However, the evidence for a platelet count threshold of 10 x 10(9)/L being equivalent to 20 x 10(9)/L is not as definitive as it would first appear and further research is required. Thirdly, platelet dose does not affect the number of patients with significant bleeding, but whether it affects number of days each patient bleeds for is as yet undetermined. There is no evidence that platelet dose affects the incidence of WHO grade 4 bleeding.Prophylactic platelet transfusions were more effective than platelet-poor plasma at preventing bleeding.

When Less is More: Can We Abandon Prophylactic Platelet Transfusion in Dengue Fever?

Dengue fever (DF) has several hematological manifestations including thrombocytopenia and increased bleeding risk. Prophylactic platelet transfusion—in the absence of major bleeding—is utilized in DF with thrombocytopenia with the intention of preventing hemorrhagic complications. However, prophylactic platelet transfusion in DF is neither standardized nor supported by clinical evidence. We conclude that risks, costs and poor resource utilization associated with prophylactic platelet transfusion in DF far outweigh any potential hematological benefit, and as such, should not constitute routine clinical practice. Key words: Thrombocytopenia, Preventitive, Arbovirus, Bleeding, Hemorrhage

Significant reduction of red blood cell transfusion requirements by changing from a double-unit to a single-unit transfusion policy in patients receiving intensive chemotherapy or stem cell transplantation

BACKGROUND

Traditionally, single-unit red blood cell transfusions were believed to be insufficient to treat anemia, but recent data suggest that they may lead to a safe reduction of transfusion requirements. We tested this hypothesis by changing from a double- to a single-unit red blood cell transfusion policy.

DESIGN AND METHODS

We performed a retrospective cohort study in patients with hematologic malignancies receiving intensive chemotherapy or hematopoietic stem cell transplantation. The major end-points were the reduction in the total number of red blood cell units per therapy cycle and per day of aplasia. The study comprised 139 patients who received 272 therapy cycles. Overall 2212 red blood cell units were administered in 1548 transfusions.

RESULTS

During the periods of the double- and single-unit policies, one red blood cell unit was transfused in 25% and 84% of the cases and the median number of red blood cell units per transfusion was two and one, respectively. Single-unit transfusion led to a 25% reduction of red blood cell usage per therapy cycle and 24% per aplasia day, but was not associated with a higher out-patient transfusion frequency. In multivariate analysis, single-unit transfusion resulted in a reduction of 2.7 red blood cell units per treatment cycle (P = 0.001). The pre-transfusion hemoglobin levels were lower during the single-unit period (median 61 g/L versus 64 g/L) and more transfusions were administered to patients with hemoglobin values of 60 gl/L or less (47% versus 26%). There was no evidence of more severe bleeding or more platelet transfusions during the single-unit period and the overall survival was similar in both cohorts.

CONCLUSIONS

Implementing a single-unit transfusion policy saves 25% of red blood cell units and, thereby, reduces the risks associated with allogeneic blood transfusions.