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Thrombocytopenia is common among sick neonates, affecting 20–35% of all patients admitted to the neonatal intensive care unit (NICU). While most cases of neonatal thrombocytopenia are mild or moderate and resolve within 7–14 days with appropriate therapy, 2.5–5% of NICU patients develop severe thrombocytopenia, sometimes lasting for several weeks and requiring >20 platelet transfusions. The availability of thrombopoietic agents offers the possibility of decreasing the number of platelet transfusions and potentially improving the outcomes of these infants. Adding thrombopoietin (TPO) mimetics to the therapeutic armamentarium of neonatologists, however, will require careful attention to the substantial developmental differences between neonates and adults in the process of megakaryocytopoiesis and in their responses to TPO. Taken together, the available data suggest that TPO mimetics will stimulate platelet production in neonates, but might do so through different mechanisms and at different doses than those established for adults. In addition, the specific groups of thrombocytopenic neonates most likely to benefit from therapy with TPO mimetics need to be defined, and the potential non-hematological effects of these agents on the developing organism need to be considered. This review summarizes our current understanding of neonatal megakaryocytopoiesis, and examines in detail the developmental factors relevant to the potential use of TPO mimetics in neonates.

Thrombocytopenia affects up to 35% of all patients admitted to the neonatal intensive care unit (NICU). The causes of thrombocytopenia in neonates are very diverse, and include immune and non-immune disorders. Most cases of thrombocytopenia encountered in the NICU are non-immune, and these will constitute the focus of this review. Specifically, we will first discuss the biological differences between neonatal and adult megakaryocytopoiesis, which contribute to explain the vulnerability of neonates to develop thrombocytopenia. Next, we will review new diagnostic tools that have allowed for a better evaluation of platelet production in neonates, without having to obtain a bone marrow sample. Finally, we will summarize our current understanding of the mechanisms underlying the thrombocytopenia in several common neonatal conditions, such as chronic intrauterine hypoxia, sepsis and necrotizing enterocolitis (NEC), and viral infections. A better understanding of the mechanisms underlying these varieties of thrombocytopenia is critical to develop disease-specific treatment protocols, and to begin to entertain the possibility of using novel thrombopoietic growth factors to treat selected neonates with severe thrombocytopenia.

Dengue fever and dengue haemorrhagic fever have emerged as a global public health problem in recent decades. The practice of platelet transfusion has been adapted into the standard clinical practice in management of hospitalized dengue patients. The exact indications and situations in which platelet have to be transfused may vary greatly. Blood components especially platelet concentrates due to their short shelf life are frequently in limited supply. Hence, appropriate use of blood is required to ensure the availability of blood for patients in whom it is really indicated, as well as to avoid unnecessary exposure of the patients to the risk of transfusion reactions and transmission of blood borne infection. The present study was conducted to evaluate the appropriateness of platelet transfusion done in dengue patients with thrombocytopenia. The present study was conducted on 343 serologically confirmed dengue patients admitted at JSS University Hospital between 1st January and 30th August 2009. Clinical data, platelet count and platelet requirements were analyzed. Among the 343 serologically confirmed cases, the prevalence of thrombocytopenia (platelet count < 100,000/cumm) was 64.72% (222 patients) and bleeding manifestations were recorded in 6.12% (21 patients). 71 (20.7%) patients of dengue cases received platelet transfusion. Among them 34 (47.89%) patients had a platelet count <20,000/cumm, 28 patients (39.44%) had platelet counts in the range of 21–40,000/cumm while the remaining 9 (12.67%) patients had platelet count between 41–100,000/cumm. Out of 37 patients with a platelet count >20,000/cumm 11 patients had haemorrhagic manifestations such as petechiae, gum bleeding, epistaxis etc., which necessitates the use of platelet transfusion. However, the remaining 26 patients with platelet count >20,000/cumm and with no haemorrhagic manifestations received inappropriate platelet transfusion. Transfusion of 36.62% of platelet concentrate was inappropriate. The study emphasizes the need for development of specific guidelines for transfusion of blood components, constant interaction and co-ordination amongst clinicians and transfusion centre for implementation of these guidelines and a regular medical audit to review the optimal utilization of blood components.

Background

The overall prevalence of thrombocytopenia in neonates admitted to neonatal intensive care units ranges from 22 to 35%. There are only a few small studies that outline the relationship between the severity of thrombocytopenia and the risk of bleeding. This makes it difficult to form an evidence-based threshold for platelet transfusions in neonatal patients. The aim of this study was to determine the prevalence of thrombocytopenia in a tertiary neonatal intensive care unit and to study the relation between thrombocytopenia and the risk of intraventricular hemorrhage (IVH).

Methods

We performed a retrospective cohort study of all patients with thrombocytopenia admitted to our neonatal tertiary care nursery between January 2006 and December 2008. Patients were divided into 4 groups according to the severity of thrombocytopenia: mild (100-149 × 109/L), moderate (50-99 × 109/L), severe (30-49 × 109/L) or very severe (< 30 × 109/L). The primary outcome was IVH ≥ grade 2. Pearson's chi-squared and Fischer's exact tests were used for categorical data. ANOVA, logistic regression analysis and multivariate linear regression were used for comparisons between groups and for confounding factors.

Results

The prevalence of thrombocytopenia was 27% (422/1569). Risk of IVH ≥ grade 2 was 12% (48/411) in neonates with versus 5% (40/844) in neonates without thrombocytopenia (p < 0.01). After multivariate linear regression analysis, risk of IVH ≥ grade 2 in the subgroups of thrombocytopenic infants was not significantly different (p = 0.3).

After logistic regression analysis the difference in mortality rate in neonates with and without thrombocytopenia was not significant (p = 0.4). Similarly, we found no difference in mortality rate in the subgroups of neonates with thrombocytopenia (p = 0.7).

Conclusion

Although IVH ≥ grade 2 occurs more often in neonates with thrombocytopenia, this relation is independent of the severity of thrombocytopenia. Prospective studies should be conducted to assess the true risk of hemorrhage depending on underlying conditions. Randomized controlled trials are urgently needed to determine a safe lower threshold for platelet transfusions.

Ten cases of isoimmune neonatal thrombocytopenic purpura (4 pairs of siblings and 2 singletons) are described. The condition was diagnosed by excluding other causes of thrombocytopenia , and in 8 cases it was confirmed by detecting antiplatelet antibodies in the mother. Perhaps steroids should be given to affected infants as soon as the condition is diagnosed in order to stabilise the capillary membrane. Exchange transfusion, using platelet antigen-negative blood if available, helps to remove antibodies and should be followed by the infusion of antigen-negative platelets, easily obtained from the mother by platelet-phoresis. The use of random donor platelets (as in 3 of these cases) was ineffective because 98% of the population are platelet antigen-positive. Nine of the infants recovered completely. The exception was an infant who developed hydrocephalus, possibly as a result of intracranial haemorrhage.

BACKGROUND

Blood group A and B antigens are expressed only weakly on platelets (PLTs) of most individuals but are very strongly expressed on PLTs from approximately 1 percent of normal subjects (Type II high expressers). The implications of this trait for transfusion medicine are undefined.

STUDY DESIGN AND METHODS

A family was studied in which two Group B infants were born with neonatal thrombocytopenia, whereas a third infant whose blood group was A2 had a normal PLT count at birth.

RESULTS

Serologic studies demonstrated a maternal antibody that reacted strongly with PLTs from the father and the two group B children in flow cytometry and with GPIIb/IIIa from their PLTs in solid-phase assays. No PLT-specific antibodies were detected in maternal serum sample, but it contained a high-titer immunoglobulin G antibody specific for blood group B. All PLT-reactive antibody in the mother’s serum was removed by absorption with pooled, washed group A and B red cells (RBCs). Studies with monoclonal anti-B and measurement of serum B-glycosyltransferase activity showed that the father and both group B children were Type II high expressers of blood group B.

CONCLUSIONS

The findings indicate that high-titer blood group antibodies acquired from the mother can cause thrombocytopenia in infants possessing the Type II high-expresser phenotype despite competition for antibody binding by blood group antigens expressed on RBCs and other tissues.

Purpose

The effects of maternal systemic lupus erythematosus (SLE) on neonatal prognosis were examined by comparing clinical features of full-term babies born to lupus mothers and age- and parity-matched controls.

Materials and Methods

From January 2000 to December 2005, 39 singletons were born to 37 SLE women. Excluding 11 cases of prematurity and preeclampsia, 28 full-term neonates formed the lupus group. The control group included 66 full-term babies. The retrospective study examined medical records and compared gestational age, birth weight, days of hospital stay, small for gestational age (SGA) frequency, Apgar scores < 7, and parity. Lupus neonates were tested for anti-nuclear antibody (ANA) and platelet count, and electrocardiogram was performed.

Results

Average gestational age (38 vs. 39 weeks, p < 0.05) and birth weight (2,775 vs. 3,263 g, p < 0.05) were significantly different between the SLE and control groups. SGA frequency was higher in the SLE group (25% vs. 4.5%, p < 0.05). No significant difference was observed in Apgar score, birth weight, gestational age, SGA frequency, and platelet count between lupus subgroups formed based on anti-dsDNA antibody levels and antiphospholipid antibody status.

Conclusion

The association of maternal ANAs, antiphospholipid antibodies, and drug history with neonatal prognosis could not be elucidated. However, even in uncomplicated pregnancies, maternal lupus is disadvantageous for gestational age, birth weight, and SGA frequency.

Background

Thrombocytopenia is frequent among neonates, and 20-25% of affected infants are treated with platelet transfusions. These are frequently given for mild thrombocytopenia (platelets 50-100×109/L), largely due to the known hyporeactivity of neonatal platelets. In tests of primary hemostasis, however, neonates have shorter bleeding and closure times (CTs) than adults. This has been attributed to their higher hematocrits, higher von Willebrand factor (VWF) concentrations, and predominance of longer VWF polymers.

Objective

To determine whether the “transfusion” of adult (relatively hyper-reactive) platelets into neonatal blood results in a hypercoagulable profile.

Methods

Cord blood (CB) and adult peripheral blood (PB) were separated (using a modified buffy-coat method) to generate miniaturized platelet concentrates (PCs) and thrombocytopenic blood. PB- and CB-derived PCs (n=7 per group) were then “transfused” in-vitro into thrombocytopenic CB and PB. The effects of autologous vs. allogeneic (developmentally mismatched) “transfusions” were evaluated using whole blood aggregometry, platelet function analyzer (PFA-100), and thromboelastography (TEG).

Results

Adult platelets aggregated significantly better than neonatal platelets in response to TRAP, ADP and collagen, regardless of the blood into which they were transfused. The “transfusion” of adult platelets into thrombocytopenic CB resulted in shorter CTs-Epi (PFA-100) and higher clot strength and firmness (TEG), compared to “transfusion” of neonatal autologous platelets.

Conclusions

In vitro “transfusion” of adult platelets into neonatal blood results in shorter CTs than “transfusion” with neonatal platelets. Our findings should raise awareness of the differences between the neonatal and adult hemostatic system and the potential “developmental mismatch” associated with platelet transfusions on neonatal hemostasis.

Background/Aim:

Hypersplenism due to splenic congestion is observed in portal hypertensive patients. This study was done to know the change in platelets count following early ligation of splenic artery during splenectomy in patients with thrombocytopenia due to portal hypertension with a hypothesis that splenic decongestion results in increased platelets count; thereby platelet transfusion can be avoided.

Materials and Methods:

Patients with platelets count <100,000 per mm3 due to portal hypertension were involved and we followed a protocol of ligating splenic artery first, followed by 30 minutes waiting period for splenic decongestion. Blood sample was collected at 5 and 30 minutes for the estimation of platelets count.

Results:

Significant rise in platelets was observed after 5 and 30 minutes of early ligation of splenic artery with mean rise being 23735 ± 15417 and 35085 ± 20458 per mm3, respectively. The rise in platelets at 30 minutes was significant when compared with 5 minutes rise with mean platelets count being 91661 and 103070 per mm3 at 5 and 30 minutes, respectively. The platelets rise was equal to 4 and 6 units of platelets concentrates, respectively.

Conclusion:

Early ligation of splenic artery during splenectomy for portal hypertension results in significant rise in platelets after 5 and 30 minutes. This method conserves platelets and avoids platelets transfusion and its complications.

Three newborn babies with congenital immune amegakaryocytic thrombocytopenia are described. Two were siblings. The mothers' sera showed antibody against both pooled random platelets and lymphocytes of type HLA-A2. Two babies had transient thrombocytopenia and leucopenia and made a full haematological recovery. One baby died aged four hours having had no haematological investigations during life. Histological examination of the bone marrow in all three babies (two by trephine biopsy; one at necropsy) confirmed a deficiency of megakaryocytes. It is suggested that anti-HLA-A2 may cause neonatal thrombocytopenia by depressing megakaryocytes instead of, or in addition to, any direct effect on platelets.

A 22 year old male presented with breathlessness on exertion, ecchymosis, jaundice and features of worsening right heart failure for the last fifteen days. On physical examination, he had a mid diastolic murmur in the tricuspid area and an ejection systolic murmur in the pulmonary area. Bone marrow histopathology report showed an increased in megakaryocytes count. Routine investigations reports were normal. Echocardiography and computerized tomography (CT) revealed a single mobile large intra cardiac mass originating from the right atrium and causing dynamic obstruction of the right ventricular inflow and outflow tract. Associated fatal thrombocytopenia did not respond to intravenous steroids or platelet transfusion. Patient could not be operated because of very low platelet count, and died during hospital stay before excision biopsy could be done. Pathological autopsy was not done. This is a rare case, as the fatal thrombocytopenia observed here was the result of mechanical effects like frictional and shear force, which can be attributed to the physical presence of a large intra cardiac mass resulting in obstruction to flow.

Objectives

To determine the risks and benefits associated with the transfusion of packed red blood cells (PRBCs) in extremely low birth weight (ELBW) infants. We hypothesized that when ELBW infants underwent transfusion with the University of Washington Neonatal Intensive Care Unit (NICU) 2006 guidelines, no clinical benefit would be discernible.

Study design

We conducted a retrospective chart review of all ELBW infants admitted to the NICU in 2006. Information on weight gain, apnea, heart rate, and respiratory support was collected for 2 days preceding, the day of, and 3 days after PRBC transfusion. The incidence, timing, and severity of complications of prematurity were documented.

Results

Of the 60 ELBW infants admitted to the NICU in 2006, 78% received PRBC transfusions. Transfusions were not associated with improved weight gain, apnea, or ventilatory/oxygen needs. However, they were associated with increased risk of bronchopulmonary dysplasia, necrotizing enterocolitis, and diuretic use (P < .05). Transfusions correlated with phlebotomy losses, gestational age, and birth weight. No association was found between transfusions and sepsis, retinopathy of prematurity, or erythropoietin use.

Conclusions

When our 2006 PRBC transfusion guidelines were used, no identifiable clinical benefits were identified, but increased complications of prematurity were noted. New, more restrictive guidelines were developed as a result of this study.

Background.

Human platelet antigens (HPA) are determinant in several platelet-specific alloimmune disorders, such as neonatal alloimmune thrombocytopenia, post-transfusion purpura and platelet transfusion refractoriness. The distribution of HPA systems in the Malaysian population is not known. Defining the patterns of HPA systems provides a basis for risk assessment and management of the above complications.

Materials and methods.

The aim of this study was to investigate the distribution of HPA -1 to -6 and -15 in the three major ethnic groups (Malay, Chinese and Indian) in the Malaysian population. A total of 600 random donor samples, 200 from each of the three ethnic groups, were genotyped by means of real time polymerase chain reaction (PCR) with hydrolysis probes and PCR-restriction fragment length polymorphism (PCR-RFLP).

Results.

The most common genotype observed in this study was HPA-1a/1a-2a/2a-3a/3b-4a/4a-5a/5a-6a/6a-15a/15b (17%) followed by HPA-1a/1a-2a/2a-3a/3a-4a/4a-5a/5a-6a/6a-15a/15b (14.33%). The allele frequencies of HPA in Malays and Chinese were found to be similar those of other East and South-East Asian populations, while those of Indians were comparable to the frequencies found in Europeans.

Conclusion.

The results of this study have been useful for determining the distribution of HPA polymorphisms in this region and for potential clinical implications.

Background

Platelet transfusion is required in the acute phase of some thrombocytopenic disorders in order to prevent potentially dangerous hemorrhages.The purpose of this study was to assess the increase in platelet count following a slow platelet transfusion.

Methods

Patients suffering from thrombocytopenia due to various underlying diseases were enrolled in the prospective pilot feasibility trial and were randomly divided into two groups. Standard platelet transfusion was administered in one group, while slow transfusion was used in the other. The platelet count was examined at 1 hour, 24 hours, and 1 week following the transfusions.

Results

Although the platelet count was higher following 1 hour after transfusion via the standard method, the count tended to be higher 1 week after the transfusion in the slow transfusion group. This difference, however, only turned out to be statistically significant amongst females.

Conclusion

A therapy of slow platelet transfusion might be more effective for the prevention of platelet loss. Further studies will be required to strengthen this hypothesis.

Double volume (170 ml/kg body weight) exchange transfusion was done in 52 term infants in the first week of life for neonatal hyperbilirubinemia. The M:F ratio was 1.08:1 and 37 (71.1%) babies were of low birth weight. Causes of jaundice were hemolytic in 46.2% and non-hemolytic in 41.3% cases; in 13.5% babies no cause of jaundice could be found. After exchange transfusion a fall of 14.6% and 47.4% was observed in the hemoglobin and serum bilirubin levels respectively. There was significant (p=0.0414) rise in the mean mid exchange and post-exchange serum sodium levels as compared to pre-exchange values and it was found to be due to higher donor's serum sodium levels (p=0.007). There was no effect on the serum potassium levels during or after ET.

In general serum calcium levels significantly increased at mid-exchange period (p=0.0029) but post-exchange levels were same as pre-exchange. Donor's serum calcium level had no effect on the infant's serum calcium level (p=0.993). There was no change in the serum phosphate and blood urea levels during and after exchange-transfusion. The plasma glucose was significantly raised during and after ET and plasma glucose of the donors had significant effect on the infant's plasma glucose levels (p=0.043). Similarly plasma osmolality also showed significant increase during and after ET which was due to the effect of donor's plasma osmolality (p=0.007).

Introduction

Sunitinib is an oral multi-targeted tyrosine kinase inhibitor approved for first line treatment for metastatic renal cell carcinoma and imatinib-resistant metastatic gastrointestinal stromal tumors. Sunitinib administration can cause myelosuppression resulting in neutropenia and thrombocytopenia. Here we present the case of a patient with metastatic renal cell carcinoma who developed sunitinib-induced immune-mediated thrombocytopenia and who was treated with withdrawal of sunitinib and administration of intravenous immunoglobulin and steroids.

Case presentation

This case report describes a 70-year-old Aboriginal Australian with a diagnosis of metastatic renal cell carcinoma. Three weeks after the initiation of sunitinib he developed epistaxis and was admitted with thrombocytopenia (platelets 7 × 109/L) which was found to be refractory to platelet transfusion. Sunitinib was stopped and he was treated with intravenous immunoglobulin and steroids. His platelet count rapidly improved and returned to baseline in three weeks. Only two cases of sunitinib-induced immune-mediated thrombocytopenia have been described in the literature.

Conclusion

Clinicians should have a high index of suspicion for the potential of immune-mediated thrombocytopenia after the initiation of multi-targeted tyrosine kinase inhibitors such as sunitinib. This is a diagnosis of exclusion and can be safely treated by drug withdrawal.

ABSTRACT

Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is the commonest cause of severe neonatal thrombocytopenia. FNAIT is usually suspected in neonates with bleeding or severe, unexplained, and/or isolated postnatal thrombocytopenia. Affected fetuses should be managed in referral centers with experience in the ante-natal management of FNAIT. Close collaboration is required between specialists in fetal medicine, obstetrics, hematology/transfusion medicine, and pediatrics. The mother and her partner should be provided with detailed information about FNAIT and its potential clinical consequences, and the benefits and risks of different approaches to ante-natal management. There has been huge progress in the ante-natal management of FNAIT over the last 20 years. However, the ideal effective treatment without significant side effects to the mother or fetus has yet to be determined.

Key issues:

Fetal and neonatal alloimmune thrombocytopenia is a condition that is underdiagnosed.

Immunization seldom occurs in the first pregnancy.

Immunization takes place in association with delivery in most cases.

Anti-HPA-1a level is a predictor for the severity of thrombocytopenia.

Introduction

Post-transfusion purpura is a rare immunohematological disorder characterized by severe thrombocytopenia following transfusion of blood components and induced by an alloantibody against a donor platelet antigen. It occurs primarily in women sensitized by pregnancy and is most commonly caused by anti-human platelet antigen-1a antibodies. Here, we describe what we believe to be the first documented case of an African-American man who developed post-transfusion purpura due to an anti-human platelet antigen-5b alloantibody after receiving multiple blood products.

Case presentation

A 68-year-old African-American man initially admitted with atrial flutter was started on anticoagulation treatment, which was complicated by severe hematemesis. On days 4 and 5 of hospitalization, he received six units of packed red blood cells, and on days 4, 13 and 14 he received plasma. His platelet count began to drop on day 25 and on day 32 reached a nadir of 7 × 109/L. His platelet count increased after receiving intravenous immune globulin. An antibody with reactivity to human platelet antigen-5b was detected by a solid-phase enzyme-linked immunoassay. Our patient was homozygous for human platelet antigen-5a.

Conclusion

This case emphasizes the importance of including post-transfusion purpura in the differential diagnosis for both men and women with acute onset of thrombocytopenia following transfusion of blood products. The prompt recognition of this entity is crucial for initiation of the appropriate management.

Background

Malaria is an annual killer of over one million people globally and its essential co-morbidity is anaemia. Cord blood, because of its rich mix of foetal and adult haemoglobin, high platelet and WBC counts, hypo-antigenic nature, altered metabolic profile and high affinity for oxygen as well as its anti-malarial effect, is an ideal choice in malaria with anaemia, necessitating blood transfusion.

Methods

This paper presents an alternative protocol for fresh whole blood/packed cell transfusion from the hospital's biological waste resources, i.e., the placenta, after the birth of a healthy baby from a healthy mother. This collected blood was routinely transfused to patients admitted in our hospital with severe anaemia in the background of confirmed malaria. 94 units of placental umbilical cord whole blood were collected after lower uterine caesarean section (LUCS) from consenting mothers (from 1st April 1999 to April 2005), and safely transfused to 39 informed, consenting patients (age varying from 8 to 72 years). The collected volume of cord blood from each placenta (Unit) varied from 52 ml to 143 ml, with a mean packed cell volume of 48.9 ± 4.1 SD and a mean haemoglobin concentration of 16.4 Gm percent ± 1.6 Gm percent SD. The blood was immediately transfused after following the standard adult blood transfusion protocol of screening and cross-matching between the donor and the recipient. On occasion, the collected cord blood was preserved in the refrigerator, if no volunteer was readily available, and transfused within 72 hours of collection.

Results

Cord blood transfusion was tested on twenty two patients infected with Plasmodium falciparum and 17 patients with Plasmodium vivax. For inclusion in this study, the patient's plasma haemoglobin had to be 8 gm percent or less (the pre-transfusion haemoglobin in the malaria-infected patients in this series varied from 5.4 gm/dl to 7.9 gm/dl). The rise of haemoglobin within 72 hours of two units of freshly collected cord blood transfusion was 0.5 gm/dl to 1.6 gm/dl. Each patient received two to six units of freshly collected cord blood transfusion (two units at a time), depending on availability and compatibility. No clinical immunological or non-immunological reaction has been encountered in this series.

Conclusion

Properly screened cord blood is safe for transfusion, in victims of severe malarial anaemia who need transfusion support.

Objective To assess the impact of reorganisation of neonatal specialist care services in England after a UK Department of Health report in 2003.

Design A population-wide observational comparison of outcomes over two epochs, before and after the establishment of managed clinical neonatal networks.

Setting Epoch one: 294 maternity and neonatal units in England, Wales, and Northern Ireland, 1 September 1998 to 31 August 2000, as reported by the Confidential Enquiry into Stillbirths and Sudden Deaths in Infancy Project 27/28. Epoch two: 146 neonatal units in England contributing data to the National Neonatal Research Database at the Neonatal Data Analysis Unit, 1 January 2009 to 31 December 2010.

Participants Babies born at a gestational age of 27+0-28+6 (weeks+days): 3522 live births in epoch one; 2919 babies admitted to a neonatal unit within 28 days of birth in epoch two.

Intervention The national reorganisation of neonatal services into managed clinical networks.

Main outcome measures The proportion of babies born at hospitals providing the highest volume of neonatal specialist care (≥2000 neonatal intensive care days annually), having an acute transfer (within the first 24 hours after birth) and/or a late transfer (between 24 hours and 28 days after birth) to another hospital, assessed by change in distribution of transfer category (“none,” “acute,” “late”), and babies from multiple births separated by transfer. For acute transfers in epoch two, the level of specialist neonatal care provided at the destination hospital (British Association of Perinatal Medicine criteria).

Results After reorganisation, there were increases in the proportions of babies born at 27-28 weeks’ gestation in hospitals providing the highest volume of neonatal specialist care (18% (631/3495) v 49% (1325/2724); odds ratio 4.30, 95% confidence interval 3.83 to 4.82; P<0.001) and in acute and late postnatal transfers (7% (235) v 12% (360) and 18% (579) v 22% (640), respectively; P<0.001). There was no significant change in the proportion of babies from multiple births separated by transfer (33% (39) v 29% (38); 0.86, 0.50 to 1.46; P=0.57). In epoch two, 32% of acute transfers were to a neonatal unit providing either an equivalent (n=87) or lower (n=26) level of specialist care.

Conclusions There is evidence of some improvement in the delivery of neonatal specialist care after reorganisation. The increase in acute transfers in epoch two, in conjunction with the high proportion transferred to a neonatal unit providing an equivalent or lower level of specialist care, and the continued separation of babies from multiple births, are indicative of poor coordination between maternity and neonatal services to facilitate in utero transfer before delivery, and continuing inadequacies in capacity of intensive care cots. Historical data representing epoch one are available only in aggregate form, preventing examination of temporal trends or confounding factors. This limits the extent to which differences between epochs can be attributed to reorganisation and highlights the importance of routine, prospective data collection for evaluation of future health service reorganisations.

Objectives:

Thrombocytopenia is commonly observed in critically ill patients. This study was undertaken to evaluate the variation in platelet counts and the risk factors associated with thrombocytopenia and mortality in pediatric intensive care patients. In addition, prognostic value of platelet counts for outcome in pediatric intensive care unit was studied.

Study Design:

Prospective, observational cohort analysis.

Setting:

8- bedded pediatric intensive care unit of a tertiary care teaching hospital.

Patients:

All consecutively admitted patients (n=138) staying in the pediatric intensive care unit (PICU) for at least 48h over a 7 months period were studied.

Measurements and Main Results:

Thrombocytopenia was defined as platelet counts <150.0/nL. Median 1st day Pediatric Risk of Mortality Score (PRISM) was 5 (range 0-30) and median ICU stay was 4 days (range 2-98 days). Twenty five percent patients had at least one episode of thrombocytopenia during the stay. Twenty percent of these patients had thrombocytopenia on admission and rest (80%) developed it during the PICU stay. Seventy one percent (19) of the patients developed thrombocytopenia by fourth day of admission. Patients with PICU acquired thrombocytopenia had statistically significant lower baseline, nadir and 4th day platelet counts and a significantly higher drop in platelet counts (56% vs. 6% P<0.001) as compared to non thrombocytopenic patients. PRISM score, long PICU stay, sepsis, coagulopathy, and creatinine levels were significantly associated with occurrence of thrombocytopenia. Patients with thrombocytopenia had higher probability of bleeding (34% vs. 15%, P=0.01). Higher platelet counts on admission were associated with significantly reduced risk of thrombocytopenia (P=0.00) Baseline, nadir and day-4 platelet counts, presence of thrombocytopenia on admission, sepsis, coagulopathy and a higher mean PRISM score on univariate analysis were significantly associated with mortality. Leucopenia or leucocytosis, thrombocytopenia and coagulopathy were found to significantly affect outcome. Drop in platelet counts was found to have slightly higher discriminative value for mortality prediction than PRISM on the ROC curve. The survivors had higher platelet counts throughout the PICU stay and after an initial fall in platelet counts in the PICU showed a significantly higher rise in the platelet counts in the following days than the non-survivors.

Conclusions:

Thrombocytopenia is common in PICU. Patients requiring cardiopulmonary resuscitation or with circulatory shock, coagulopathy, sepsis and with more severe disease have higher risk of developing thrombocytopenia. Thrombocytopenic patients have a higher risk of bleeding. Drop in platelet counts >27% and thrombocytopenia were independently related to mortality. Serial measurements of platelet counts are better predictors of pediatric intensive care outcome than one-time values. Any drop in platelet counts even without thrombocytopenia needs an urgent and extensive evaluation.

Background

Factors affecting the efficacy of platelet and red blood cell (RBC) transfusion in patients undergoing hematopoietic stem cell transplantation (HSCT) have not been studied extensively. We aimed to evaluate platelet and RBC transfusion efficacy by measuring the platelet corrected count increment and the hemoglobin increment, respectively, 24 h after transfusion in 105 patients who received HSCT.

Methodology/Principal Findings

Using retrospective analysis, we studied whether factors, including gender, time of transplantation, the compatibility of ABO group between HSC donors and recipients, and autologous or allogenic transplantation, influence the efficacy of blood component transfusion. We found that the infection rate of HSCT patients positively correlated with the transfusion amount, and the length of stay in the laminar flow room was associated with transfusion. We found that platelet transfusion performed during HSCT showed significantly better efficacy than that performed before HSCT. The effect of platelet transfusion in auto-transplantation was significantly better than that in allo-transplantation. The efficacy of RBC transfusion during HSCT was significantly lower than that performed before HSCT. The efficacy of RBC transfusion in auto-transplantation was significantly higher than that in allo-transplantation. Allo-transplantation patients who received HSCs from compatible ABO groups showed significantly higher efficacy during both platelet and RBC transfusion.

Conclusions

We conclude that the efficacy of platelet and RBC transfusions does not correlate with the gender of patients, while it significantly correlates with the time of transplantation, type of transplantation, and ABO compatibility between HSC donors and recipients. During HSCT, the infection rate of patients positively correlates with the transfusion amount of RBCs and platelets. The total volume of RBC units transfused positively correlates with the length of the patients’ stay in the laminar flow room.

Thrombocytopenia is a rare complication of glycoprotein IIb/IIIa treatment. We report a case of an acute profound abciximab induced thrombocytopenia and its successful management. The patient, presenting with unstable angina, underwent percutaneous coronary intervention with implantation of three drug eluting stents without receiving a clopidogrel loading dose according to guidelines. The rapid drop in the platelet count after abciximab elastomeric pump infusion was treated with drug discontinuation and platelet transfusion. The high risk of stent thrombosis was avoided by a timely readministration of the dual antiplatelet treatment.

Thrombocytopenia commonly occurs in hospitalized patients, particularly critically ill patients. We present an exemplifying case of severe heparin-induced thrombocytopenia (HIT) in an effort to solidify its high priority in the differential diagnosis of thrombocytopenia. A 75-year-old female underwent cardiac surgery with intraaortic balloon pump (IABP) placement. A platelet count drop to 25 × 10(9)/L by the third postoperative day was attributed to the IABP, which was removed. Her thrombocytopenia remained refractory to multiple platelet transfusions over several days. Right hand cyanosis then developed, attributed to a right radial arterial catheter, which was removed. All toes and fingers then showed severe ischemic changes. Ten days after the initial platelet count drop, a critical care specialist new to the treating team suspected HIT. Heparin exposure was stopped and argatroban was initiated. A HIT antibody test was subsequently strongly positive. The patients thrombocytopenia gradually resolved. No additional thromboses occurred during a 27-day intensive care unit stay. This case underscores the need for vigilance in suspecting HIT in patients with thrombocytopenia and recent heparin exposure. To avoid catastrophic outcomes in such patients, heparin should be stopped and alternative anticoagulation should be initiated, at least until HIT is excluded.

To study the antibody response to human platelet transfusions, nine thrombocytopenia patients with bone marrow failure were given 6 U (3X10(11)) of random platelet concentrates twice a week. Before transfusion, none of the patients had preexisting antibodies detectable with lymphocytotoxicity, platelet aggregation, or capillary leukoagglutination techniques. After receiving 18-78 U of platelets, they became refractory to further transfusions of random platelets and alloantibodies were detectable. Two patterns of antibody response could be identified. In three patients, the sera were not lymphocytotoxic with a panel of standard cells in which all the known HLA antigens in the first and second series were represented at least once. Yet, they caused platelet aggregation with 30, 24, and 60%, respectively, of a donor population studied. The aggregating activities were inhibited by antihuman IgG but not by antihuman IgA or antihuman IgM antiserum. The aggregating antibodies could be absorbed out with donor platelets but not lymphocytes or granulocytes. Antibodies from two of these patients aggregated platelets of their respective siblings matched for both HLA haplotypes. Transfusion of platelets from these two siblings did not increase the platelet count while platelets obtained from aggregation-negative donors did. The sera from the remaining six patients were lymphocytotoxic with 15-100% of the panel of standard cells. They also had aggregating antibodies, which could be absorbed out by both platelets and lymphocytes, suggesting that they were HLA antibodies. These data suggest that the development of platelet-specific antibodies may play an important role in the immunological rejection of isologous platelets, and should be considered in the selection of donors for patients who are refractory to platelets from random donors.