Evaluation and treatment of thrombocytopenia in the neonatal intensive care unit

Platelet Counts and Risk of Severe Retinopathy of Prematurity: A Bayesian Model-Averaged Meta-Analysis

BACKGROUND

We aimed to conduct a systematic review and Bayesian model-averaged meta-analysis (BMA) on the association between platelet counts and severe retinopathy of prematurity (ROP).

METHODS

We searched for studies reporting on platelet counts (continuous variable) or thrombocytopenia (categorical variable) and severe ROP or aggressive posterior ROP (APROP). The timing of platelet counts was divided into Phase 1 (<2 weeks) and Phase 2 (around ROP treatment). BMA was used to calculate Bayes factors (BFs). The BF10 is the ratio of the probability of the data under the alternative hypothesis (H1) over the probability of the data under the null hypothesis (H0).

RESULTS

We included 21 studies. BMA showed an association between low platelet counts and severe ROP. The evidence was strong (BF10 = 13.5, 7 studies) for phase 1 and very strong (BF10 = 51.0, 9 studies) for phase 2. Thrombocytopenia (<100 × 109/L) in phase 2 was associated with severe ROP (BF10 = 28.2, 4 studies). Following adjustment for publication bias, only the association of severe ROP with thrombocytopenia remained with moderate evidence in favor of H1 (BF10 = 4.30).

CONCLUSIONS

Thrombocytopenia is associated with severe ROP. However, the evidence for this association was tempered when results were adjusted for publication bias.

Blood Glucose, Lactate and Platelet Count in Infants with Spontaneous Intestinal Perforation versus Necrotizing Enterocolitis-A Pilot Study

The incidence of spontaneous intestinal perforation (SIP) increases up to 10% with decreasing gestational age (GA). We aimed to explore early biomarkers for predicting SIP in preterm infants. In this case-control study, neonates born at ≤34 weeks GA diagnosed with SIP were compared with GA and/or birth-weight-matched neonates diagnosed with necrotizing enterocolitis (NEC). Laboratory markers assessed prior and adjacent to the day of SIP or NEC diagnosis were evaluated. The cohort included 16 SIP and 16 matched NEC infants. Hyperlactatemia was less frequent in SIP than in NEC infants (12% vs. 50%, p = 0.02). The platelets count was lower in SIP than in NEC infants (p < 0.001). Glucose levels strongly correlated with lactate levels (p = 0.01) only in the NEC group. The odds of being diagnosed with SIP decreased as lactate levels increased (OR = 0.607, 95% CI: 0.377-0.978, p = 0.04). Our results suggest that a combination of laboratory markers, namely glucose and lactate, could help differentiate SIP from NEC at early stages so that, in the presence of an elevated blood glucose, an increase in blood lactate was associated with a decrease in the odds of being diagnosed with SIP.

Immune-Mediated Neonatal Thrombocytopenia

Immune-mediated thrombocytopenia in neonates is caused by the transplacental passage of maternally derived antiplatelet antibodies. The 2 most common causes include neonatal alloimmune thrombocytopenia, which leads to significant thrombocytopenia and risk of intracranial hemorrhage, and autoimmune thrombocytopenia, which is generally less severe. No specific guidelines for prenatal management exist for either disease; however, intravenous immune globulin treatments and systemic steroids for women with at-risk pregnancies can be useful in both diseases. In this review, we discuss the current literature and management strategies for both pregnant women and newborns with immune-mediated thrombocytopenia.

An Unusual Case of Severe Persistent Neonatal Thrombocytopenia in an Extremely Low Birth Weight, Extreme Preterm Neonate

Neonatal thrombocytopenia is a common hematological problem but refractory thrombocytopenia is very rare in neonates. A systematic and diligent workup will result in arriving at the proper diagnosis and providing accurate management in rare causes of neonatal thrombocytopenia. We report a case of severe refractory thrombocytopenia in an extremely low birth weight (ELBW)/extreme preterm baby who presented with early onset severe thrombocytopenia associated with anemia and required multiple platelet transfusions. After ruling out COVID-19 infection, sepsis and neonatal alloimmune thrombocytopenia (NAIT), the cause for severe refractory thrombocytopenia was diagnosed as Type II congenital amegakaryocytic thrombocytopenia (CAMT) by bone marrow examination and MPL gene mutation studies.

Neonatal coagulopathies: A review of established and emerging treatments

Despite the relative frequency of both bleeding and clotting disorders among patients treated in the neonatal intensive care unit, few clear guidelines exist for treatment of neonatal coagulopathies. The study and treatment of neonatal coagulopathies are complicated by the distinct hemostatic balance and clotting components present during this developmental stage as well as the relative scarcity of studies specific to this age group. This mini-review examines the current understanding of neonatal hemostatic balance and treatment of neonatal coagulopathies, with particular emphasis on emerging treatment methods and areas in need of further investigative efforts.

Role of platelets in neonatal necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is an inflammatory bowel necrosis of premature infants and is a leading cause of morbidity and mortality in infants born between 23 and 28 weeks of gestation. Fifty to 95% of all infants with NEC develop thrombocytopenia (platelet counts <150 × 109/L) within 24-72 h of receiving this diagnosis. In many patients, thrombocytopenia is severe and is treated with one or more platelet transfusions. However, the underlying mechanism(s) and biological implications of NEC-related thrombocytopenia remain unclear. This review presents current evidence from human and animal studies on the clinical features and mechanisms of platelet depletion in NEC. Anecdotal clinical experience is combined with evidence from laboratory studies and from an extensive literature search in databases PubMed, EMBASE, and Scopus and the electronic archives of abstracts presented at the annual meetings of the Pediatric Academic Societies. To avoid bias in identification of existing studies, key words were short-listed prior to the actual search both from anecdotal experience and from PubMed's Medical Subject Heading (MeSH) thesaurus. IMPACT: Fifty to 95% of infants with necrotizing enterocolitis (NEC) develop idiopathic thrombocytopenia (platelet counts <150 × 109/L) within 24-72 h of disease onset. Early clinical trials suggest that moderate thrombocytopenia may be protective in human NEC, although further work is needed to fully understand this relationship. We have developed a neonatal murine model of NEC-related thrombocytopenia, where enteral administration of an immunological stimulant, trinitrobenzene sulfonate, on postnatal day 10 induces an acute necrotizing ileocolitis resembling human NEC. In this murine model, thrombocytopenia is seen at 15-18 h due to platelet consumption and mild-moderate thrombocytopenia is protective.

Thrombocytopenia in Neonates

Thrombocytopenia defined as platelet count below 150,000/μL is not an uncommon event at the neonatal intensive care unit (NICU). In our region we calculated a prevalence of nearly 2 of 1000 live births. Early-onset neonatal thrombocytopenia (NT) occurring within the first 72 hours of life is more common than late-onset NT. Preterm infants are affected more often than term infants and bacterial infection is the most common diagnosis associated with NT. There are a lot of maternal, perinatal, and neonatal causes associated with NT and complications include bleedings with potentially life-threatening intracranial hemorrhage. Alloimmune thrombocytopenia (NAIT) often presents with severe thrombocytopenia (<30,000/μL) in otherwise healthy newborns and needs careful evaluation regarding HPA-1a antigen status and HLA typing. Platelet transfusions are needed in severe NT and threshold platelet counts might be at ≤25,000/μL irrespective of bleeding or not. Immune mediated NT recovers within 2 weeks with a good prognosis when there happened no intracranial hemorrhage. This short review gives an overview on etiology and causes of NT and recommendations regarding platelet transfusions.

Ranitidine-induced Thrombocytopenia in a Neonate - A Case Report and Review of Literature

Thrombocytopenia (platelet count <150 × 10⁹/L) regularly occurs in newborns but is especially observed in critically ill neonates. We describe the case of a small for gestational age (SGA) neonate, who showed an unexpected, severe thrombocytopenia (8 × 10⁹/L) at day 5 of life. The thrombocytopenia recovered completely after cessation of ranitidine (0.5 mg/kg/6 hr), which was started in a context of feeding difficulties. Other causes of neonatal thrombocytopenia were ruled out. Besides a brief report on a cimetidine-induced thrombocytopenia over 25 years ago, no other neonatal or pediatric cases of H₂ antagonist-induced thrombocytopenia have been reported to date, although being widely used in routine care. Moreover, several adult cases have been published. In general, neonatal thrombocytopenia, although one of the most frequent hematological conditions in newborns, is only rarely attributed to an adverse drug reaction. Clinicians should be aware of the risks for adverse reactions, especially in routinely used drugs and in critically ill patients.

Intracranial Hemorrhage and Autoimmune Thrombocytopenia in a Neonate: A Rare "Unpredictable" Event

Neonatal thrombocytopenia is a rare complication of maternal autoimmune thrombocytopenia, and no maternal predictors of its gravity and potential complications have been identified. Neonatal cerebral hemorrhage, a feared event in the setting of autoimmune thrombocytopenia, is fortunately uncommon, but it can occur in utero or in the perinatal period, with potentially serious consequences. The authors report the case of a boy born to a mother affected by autoimmune thrombocytopenia, who presented with severe thrombocytopenia at birth and developed intracranial hemorrhage despite mild maternal thrombocytopenia at delivery and a prompt preventive treatment of the newborn. Platelet count should be tested at birth in all babies born from mothers with autoimmune thrombocytopenia, irrespective of maternal platelets counts during pregnancy or at delivery, and should be closely monitored during the first days of life. Systematic early and serial cranial ultrasound might be advocated in the setting of neonatal thrombocytopenia.

Neonatal thrombocytopenia-causes and outcomes following platelet transfusions

We evaluated the causes for neonatal thrombocytopenia (NT), the duration of NT, and the indications of platelet transfusions (PT) by means of a retrospective cohort study over a 23-year period. Neonates with NT were identified via ICD-10 code D69.6. Of 371 neonates (1.8/1000 live births) with NT, the majority (312; 84.1%) had early onset thrombocytopenia, and 282 (76%) were preterm born. The most frequent causes for NT were early and late onset sepsis and asphyxia. The mean duration of thrombocytopenia was 10.2 days and was negatively correlated (KK = - 0.35) with the number of PT. PT were given to 78 (21%) neonates, 38 (49%) of whom had very severe NT. The duration of NT was positively related to the severity of NT and the number of subsequent PT. A mortality rate of 10.8% was significantly associated with bleeding signs (p < 0.05) and correlated with increasing number of PT (p < 0.05) but not with the severity of NT (p = 0.4). In the case of relevant hemorrhage, PT did not influence the mortality rate (p = 0.09). All deaths followed neonatal sepsis.

CONCLUSIONS

Prematurity and diagnoses including early and late onset sepsis and asphyxia were the most common causes of NT. Mortality was not associated with the severity of NT but increased with the number of PT. What is Known: • The causes for neonatal thrombocytopenia (NT) are well known. • The effects of platelet transfusions (PT) and its indications are still a matter of debate and recommendations differ widely. What is New: • The duration of NT is positively related to the severity of NT and the number of subsequent PT. • The mortality rate is not associated with the severity of NT but increases with increasing numbers of PT and in the case of relevant intraventricular hemorrhage (≥ grade II), PT does not influence the mortality rate.

Neonatal mice with necrotizing enterocolitis-like injury develop thrombocytopenia despite increased megakaryopoiesis

BACKGROUND

Thrombocytopenia is frequently encountered in infants with necrotizing enterocolitis (NEC). To develop a preclinical model of NEC-related thrombocytopenia, we measured serial platelet counts in 10-d-old (P10) mouse pups with trinitrobenzene sulfonic acid (TNBS)-induced NEC-like injury. We also measured platelet volume indices, immature platelet fraction (IPF), and megakaryocyte number/ploidy in these animals.

METHODS

Platelet counts, platelet volume indices, and IPF were measured in control (N = 65) and TNBS-treated pups (N = 104) using an automated hematology analyzer. Bone marrow megakaryocyte number, ploidy and CD41 expression were measured by flow cytometry. These findings were confirmed in a small cohort of P3 mice with NEC-like injury.

RESULTS

Murine pups with TNBS-mediated NEC-like injury developed thrombocytopenia at 15-24 h after exposure to TNBS. Intestinal injury was associated with increased platelet volume indices (mean platelet volume, platelet-to-large cell ratio, and platelet distribution width), and IPF, indicating increased thrombopoiesis. These mice also showed increased megakaryocyte number, ploidy, and CD41 expression, indicating increased megakaryocyte differentiation.

CONCLUSION

Similar to human NEC, murine NEC-like injury was also associated with decreased platelet counts. There was evidence of increased megakaryocyte differentiation and thrombopoiesis, which favors peripheral consumption of platelets as the likely mechanism of thrombocytopenia in these animals, over decreased platelet production.

Neonatal Thrombocytopenia as a Consequence of Maternal Preeclampsia

Introduction Preeclampsia (preE) is pregnancy-induced hypertension affecting a significant proportion of pregnant women worldwide and can cause detrimental effects in the mother and newborn. Some of the effects in the newborn include neonatal thrombocytopenia. Pertaining specifically to neonatal thrombocytopenia, several questions remain unanswered. Discussion According to the current literature, neonatal thrombocytopenia due to maternal preE is highly prevalent in the general population and the incidence is reported to be around 30% worldwide. This review gives an insight into the syndrome and summarizes the possible pathological mechanisms, the diagnostic approach, complications, and therapeutic interventions of neonatal thrombocytopenia. It also identifies the involvement of other cell lines, apart from platelets in the newborns. Furthermore, we suggest a future prospective study to investigate the pathogenesis of preE and plan a study involving animal models to come up with a possible therapeutic intervention to prevent preE and its various consequences in neonates.

Immunologic and Hematological Abnormalities in Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a leading cause of mortality in preterm infants. This article reviews the immunologic and hematological abnormalities typically seen in infants with NEC, such as elevated plasma cytokine levels, thrombocytopenia, increased or decreased neutrophil counts, low monocyte counts, and anemia. Some of these findings may provide important diagnostic and prognostic information.

Evaluation and management of thrombocytopenic neonates in the intensive care unit

Thrombocytopenia is a very frequent problem among sick neonates, affecting up to 35% of all infants admitted to the neonatal intensive care unit (NICU), and serves as an important indicator of multiple clinical conditions. The cause of the thrombocytopenia is unclear in up to 60% of affected neonates. A clinical classification of thrombocytopenia is based on the time of presentation, early (≤72 hours of life) vs. late (>72 hours of life). Early thrombocytopenia is commonly associated with feto-maternal conditions, is most commonly caused by disorders associated with placental insufficiency, and is generally mild to moderate and resolves spontaneously within 7-10 days without any intervention. In contrast, neonates who develop late-onset thrombocytopenia frequently have bacterial sepsis or necrotizing enterocolitis. It is often severe (platelets <50,000/μL), prolonged and frequently requires multiple platelet transfusions. Platelet transfusions represent the only specific therapy currently available for most thrombocytopenic neonates, even though much evidence suggests that platelet transfusions are not benign. Many of the prophylactic platelet transfusions currently given to NICU patients are unnecessary, convey no benefits, and carry known and unknown risks. For this reason, pharmacological alternatives have been investigated as potential therapies for thrombocytopenia, but they still have limited use treating the common varieties of neonatal thrombocytopenia.

Neonatal thrombocytopenia after perinatal asphyxia treated with hypothermia: a retrospective case control study

Our objective was to estimate the effect of therapeutic hypothermia on platelet count in neonates after perinatal asphyxia. We performed a retrospective case control study of all (near-) term neonates with perinatal asphyxia admitted between 2004 and 2012 to our neonatal intensive care unit. All neonates treated with therapeutic hypothermia were included in this study (hypothermia group) and compared with a historic control group of neonates with perinatal asphyxia treated before introduction of therapeutic hypothermia (2008). Primary outcome was thrombocytopenia during the first week after birth. Thrombocytopenia was found significantly more often in the hypothermia group than in the control group, 80% (43/54) versus 59% (27/46) (P = .02). The lowest mean platelet count in the hypothermia group and control group was 97 × 10(9)/L and 125 × 10(9)/L (P = .06), respectively, and was reached at a mean age of 4.1 days in the hypothermia group and 2.9 days in the control group (P < .001). The incidence of moderate/severe cerebral hemorrhage was 6% (3/47) in the hypothermia group versus 9% (3/35) in the control group (P = .64). In conclusion, neonates with perinatal asphyxia treated with therapeutic hypothermia are at increased risk of thrombocytopenia, without increased risk of cerebral hemorrhage.

Early-onset thrombocytopenia in near-term and term infants with perinatal asphyxia

BACKGROUND

Neonates after perinatal asphyxia are at increased risk of thrombocytopenia. The correlation between perinatal asphyxia and the risk and severity of early-onset thrombocytopenia is not well known.

OBJECTIVE

To estimate the incidence, severity and risk factors for early-onset thrombocytopenia in neonates after perinatal asphyxia.

METHODS

We included all newborns (gestational age ≥ 36 weeks) admitted to our neonatal nursery due to perinatal asphyxia in this retrospective study. We collected platelet counts that were obtained within the first 48 h of life to estimate the incidence and severity of early-onset thrombocytopenia.

RESULTS

A total number of 171 neonates with perinatal asphyxia were included in the study. The incidence of early-onset thrombocytopenia (platelet count < 150 × 109/l) was 51% (87/171). Several factors were associated with increased risk of early-onset thrombocytopenia, including prolonged prothrombin time (PT) [odds ratio (OR) 1·18, 95% confidence interval (CI) 1·08–1·30, P < 0·01], prolonged activated partial thromboplastin time (APTT) (OR 1·07, 95% CI 1·03–1·11, P < 0·01), low Apgar score at 10 min (OR 1·25, 95% CI 1·08–1·45, P < 0·01) and high serum lactate (OR 1·12, 95% CI 1·06–1·19, P < 0·01). After multiple logistic regression analysis, we found an independent association between early-onset thrombocytopenia and prolonged PT (OR 1·15, 95% CI 1·00–1·33, P = 0·045) and higher lactate level (OR 1·15, 95% CI 1·03–1·28, P = 0·01).

CONCLUSIONS

Early-onset thrombocytopenia occurs frequently in neonates after perinatal asphyxia and is independently associated with PT and lactate level.

Neonatal necrotizing enterocolitis: Clinical challenges, pathophysiology and management

NEC remains a major concern for neonatologists, surgeons, and gastroenterologists due to its high morbidity and mortality. These infants often have poor developmental outcome, and contribute to significant economic burden resulting in marked stress in these families. By developing and adhering to strict feeding protocols, encouraging human milk feeding preferably from the infant's mother, use of probiotics, judicious antibiotic use, instituting blood transfusion protocols, the occurrence of NEC may possibly be reduced. However, because of its multifactorial etiology, it cannot be completely eradicated in the NICUs, particularly in the extremely premature infants. Ongoing surveillance of NEC and quality improvement projects may be beneficial.

A consistent approach to platelet transfusion in the NICU

Platelet transfusions are the principal means of treating thrombocytopenia in neonatal intensive care units (NICUs), and are generally used as treatment of thrombocytopenic neonates who have active bleeding and as prophylactic administration in thrombocytopenic neonates who do not have hemorrhage but appear to be at high risk for bleeding. In this article, we summarize the rationale, benefits and risks of platelet transfusions in neonates. We review the importance of choosing the best product available for platelet transfusion, and we emphasize the importance of adopting and adhering to transfusion guidelines.

The surgical management of necrotizing enterocolitis

Necrotizing enterocolitis (NEC), a common cause of neonatal morbidity and mortality, is strongly associated with prematurity and typically occurs following initiation of enteral feeds. Mild NEC is adequately treated by cessation of enteral feeding, empiric antibiotics, and supportive care. Approximately 50% of affected infants will develop progressive intestinal necrosis requiring urgent operation. Several surgical techniques have been described, but there is no clear survival benefit for any single operative approach. While debate continues regarding the optimal surgical management for infants with severe NEC, future progress will likely depend on the development of improved diagnostic tools and preventive therapies.

Haematological abnormalities in neonatal necrotizing enterocolitis

OBJECTIVE

Necrotizing enterocolitis (NEC) is a leading cause of morbidity and mortality in preterm infants born prior to 32 weeks gestation or with a birth weight less than 1500 grams. In this article, we review hematological abnormalities associated with NEC.

METHODS

A literature search was performed using the databases PubMed, EMBASE, and Scopus, and the electronic archive of abstracts presented at the annual meetings of the Pediatric Academic Societies.

RESULTS

Thrombocytopenia, disseminated intravascular coagulation, increased or decreased neutrophil counts, and hemolytic anemia are frequent events in NEC.

CONCLUSIONS

NEC is associated with several hematological abnormalities, which may play a direct or indirect role in the pathogenesis of gut mucosal injury, and may also carry important prognostic information.

Thrombocytopenia and bacterial sepsis in neonates

Thrombocytopenia is one of the common hematological problems encountered in the neonatal period particularly in the sick newborns, premature babies and neonates admitted in neonatal intensive care units and usually indicate an underlying pathologic process. Thrombocytopenia is reported in neonates with bacterial, fungal, rickettsial, protozoal and viral infection. Some patients with bacterial septicemia may develop coagulopathy associated with DIC. The presence of thrombocytopenia is seen frequently in early sepsis with or without laboratory evidence of overt DIC. This study was conducted on 85 neonates admitted in NICU with clinical diagnosis of septicemia and 50 age and weight matched neonates served as control. Thrombocytopenia was seen in 83.5% cases where as bacterial culture was positive in only 41.1% cases. Further it was noted that, in gram negative (Gm -ve) septicemia, thrombocytopenia was more severe as compared to gram positive (Gm +ve) septicemia. It is concluded that thrombocytopenia is early predictor of septicemia but other causes of neonatal thrombocytopenia should also be ruled out.

Is a small platelet mass associated with intraventricular hemorrhage in very low-birth-weight infants?

OBJECTIVE

We sought to determine whether, among very low-birth-weight (VLBW) neonates, the platelet mass was associated with common perinatal factors, and whether a low platelet mass in the first days following birth was associated with a higher incidence and/or severity of intraventricular hemorrhage (IVH).

STUDY DESIGN

This was a cross-sectional, retrospective cohort analysis of VLBW infants admitted to a level 3 neonatal intensive care unit from June 2003 to July 2006, n=408. Platelet mass was calculated and recorded on the day of birth and for 2 consecutive days thereafter. All neonates had a screening cranial sonogram on day 4 of life. Statistical analysis included analysis of variance and Mann-Whitney U-test.

RESULT

Neonates born to mothers with pre-eclampsia had a smaller platelet mass (1921 fl/nl ± 603 vs 2297 fl/nl ± 747; P<0.01). The same was found among neonates with intrauterine growth restriction (IUGR). In contrast, neonates born after histological chorioamnionitis had a larger platelet mass (2400 fl/nl ± 749 vs 2036 fl/nl ± 674; P<0.01). No effect of platelet mass, measured on the day of birth, was observed related the outcomes of IVH, severe IVH or death. However, those with a platelet mass <10th percentile on the 2 subsequent days following birth were more likely to have severe IVH or death.

CONCLUSION

Among VLBW neonates, pre-eclampsia and IUGR are associated with a lower platelet mass, owing to their effect on platelet count. Histological chorioamnionits is associated with a larger platelet mass. A mass <10th percentile on the days following birth was associated with severe IVH and/or death, but it remains unclear whether this is a cause of, or an effect of, the IVH.

Neonatal alloimmune thrombocytopenia: a case study

Neonatal alloimmune thrombocytopenia (NAIT) is a life-threatening disorder caused by fetomaternal platelet incompatibility analogous to that seen in rhesus (Rh) disease. In NAIT , maternal immunoglobulin G (IgG) antiplatelet antibodies cross the placenta, resulting in rapid destruction and removal of fetal platelets by the reticuloendothelial system. Studies have shown that NAIT has an incidence of 1 of 1,000 live births, with a mortality rate of 10-15 percent and the risk of long-term morbidities up to 20-60 percent if intracranial hemorrhage (ICH) occurs. This column will discuss the pathophysiology, differential diagnosis, morbidities, and treatment of NAIT and conclude with a relevant case study.

Pathophysiology and treatment of septic shock in neonates

Neonatal septic shock is a devastating condition associated with high morbidity and mortality. Definitions for the sepsis continuum and treatment algorithms specific for premature neonates are needed to improve studies of septic shock and assess benefit from clinical interventions. Unique features of the immature immune system and pathophysiologic responses to sepsis, particularly those of extremely preterm infants, necessitate that clinical trials consider them as a separate group. Keen clinical suspicion and knowledge of risk factors will help to identify those neonates at greatest risk for development of septic shock. Genomic and proteomic approaches, particularly those that use very small sample volumes, will increase our understanding of the pathophysiology and direct the development of novel agents for prevention and treatment of severe sepsis and shock in the neonate. Although at present antimicrobial therapy and supportive care remain the foundation of treatment, in the future immunomodulatory agents are likely to improve outcomes for this vulnerable population.

Role of innate host defenses in susceptibility to early-onset neonatal sepsis

Neonatal sepsis continues to take a devastating toll globally. Although adequate to protect against invasive infection in most newborns, the distinct function of neonatal innate host defense coupled with impairments in adaptive immune responses increases the likelihood of acquiring infection early in life, with subsequent rapid dissemination and death. Unique differences exist between neonates and older populations with respect to the capacity, quantity, and quality of innate host responses to pathogens. Recent characterization of the age-dependent maturation of neonatal innate immune function has identified novel translational approaches that may lead to improved diagnostic, prophylactic, and therapeutic modalities.

Organism-specific platelet response and factors affecting survival in thrombocytopenic very low birth weight babies with sepsis

OBJECTIVE

To study organism-specific platelet response and factors affecting survival in thrombocytopenic very low birth weight (VLBW) babies with sepsis.

STUDY DESIGN

Very low birth weight babies (birth weight <1500 g) admitted to a single level-three intensive care unit from January 2000 to December 2005 were prospectively evaluated for sepsis by rapid screen test, blood counts and blood culture. In thrombocytopenic babies, organism-specific platelet response and its effect on various platelet parameters were evaluated. In addition, morbidity, mortality and factors affecting survival were studied.

RESULT

Sepsis was diagnosed in 230 of 620 (37%) patients. Gram-positive sepsis occurred in 20% (46/230), Gram-negative in 71% (164/230) and fungal in 8.6% (20/230) of patients. Thrombocytopenia was observed in 67% (155/230) of babies. The frequency and duration of thrombocytopenia were more with Gram-negative and fungal infections. The incidence of persistent bacteremia, multiorgan failure and death was more in thrombocytopenic neonates (P<0.01). The incidence of multiorgan failure and death was directly related to the duration of thrombocytopenia. On multiple logistic regression analysis, poor prognostic factors include a high SNAP score at admission, a severe drop in platelet count at onset of sepsis, a low platelet nadir, a prolonged duration of thrombocytopenia, a need for platelet transfusion, less number of days off ventilation and a prolonged stay in the hospital.

CONCLUSION

In thrombocytopenic VLBW babies with sepsis, organism-specific platelet response is seen. In addition, persistent bacteremia, multiorgan failure and death are more in these babies, and survival decreases with the increased severity and duration of thrombocytopenia, with prolonged ventilation and increased need for platelet transfusions.

Hematologic effects of placental pathology on very low birthweight infants born to mothers with preeclampsia

OBJECTIVE

To investigate the effect of placental pathology on neonatal neutrophils, platelets, hematocrit and nucleated red blood cells in very low birthweight (VLBW) infants born to mothers with preeclampsia.

STUDY DESIGN

Retrospective cohort study of infants with birthweight < 1500 g born to mothers with preeclampsia from july, 2002 to july, 2006 at a single level III neonatal intensive care unit. Placental pathology was reviewed for the presence of placental infarction and vasculopathy. Hematologic parameters from day of life 0, 1 and 2 were obtained. Statistical analysis included repeated-measures analysis of variance and multivariable analysis using logistic regression.

RESULT

The study sample included 203 infants with estimated gestational age of 28+/-3 weeks; 45% had placental infarctions and 26% placental vasculopathy. Infants with neutropenia and thrombocytopenia did not have an increased occurrence of placental infarction or maternal vasculopathy but were more likely to be of small gestational age (SGA) and of lower gestational age compared with infants without neutropenia or thrombocytopenia. After multivariable analysis, gestational age and SGA remained associated with both neutropenia and thrombocytopenia whereas placental infarction and vasculopathy did not remain in the models.

CONCLUSION

In our population of VLBW infants born to mothers with preeclampsia, placental pathology was common. There was no association of placental infarction or vasculopathy with neonatal neutropenia and thrombocytopenia. The data suggest that neonatal hematologic effects of maternal preeclampsia, if related to the placenta, are associated with factors other than placental histology.

Effect of pregnancy induced hypertension on mothers and their babies

OBJECTIVE

To study the hematological profile of mothers with pregnancy induced hypertension and their infants.

METHODS

The effects of maternal hypertension on the hematological profile of neonates were studied in 50 cases comparing the values with that of infants born to normotensive mothers.

RESULTS

There was higher number of preterm, Intra-Uterine Growth Restriction (IUGR) and Small for Gestational Age (SGA) babies among the infants of hypertensive mothers. There was a significantly higher incidence of thrombocytopenia and nucleated RBCs seen in these babies. Significant neutropenia was not documented and there was no increased incidence of bleeding when compared to controls.

CONCLUSION

Although there were significant changes in the hematological profile of infants born to hypertensive mothers, there was no significant increase in neonatal morbidity as a result of these changes.

Thrombocytopenia related neonatal outcome in preterms

OBJECTIVE

To investigate the thrombocytopenia and platelet transfusion related outcome in very preterm infants.

METHODS

Cases (n=94) with at least one episode of thrombocytopenia (platelet counts < 150 x 10(9)/L) and controls (n=70) were identified from a database of 1054 neonates with gestational age < or = 32 weeks admitted to a level III NICU. Thrombocytopenia and platelet transfusion related morbidity (IVH, sepsis, NEC, and bleeding) and mortality were analyzed with respect to gestational age (< 28 weeks and 28-32 weeks), severity of thrombocytopenia (mild if platelet count > or = 100 and < 150 x 10(9)/L, moderate if count > or = 50 and < 100 x 10(9)/L, and severe if platelets < 50 x 10(9)/L), age of thrombocytopenia onset (early < 72 hours and late > or =72 hours).

RESULTS

The majority of thrombocytopenia (67.0%) was diagnosed after 72 hours of age, and was mild in 12.8%, moderate in 36.2% and severe in 51.0% of the cases. Neonates with severe and moderate thrombocytopenia were more frequently born at lower gestational age and birth weight. NEC and sepsis especially that caused by Candida infection, were associated with severe thrombocytopenic events. The development of IVH was strongly associated with lower gestational age but not the severity and age of thrombocytopenia onset. Mucocutaneous bleeding complicated 18.4% of cases with severe and late-onset thrombocytopenia (7/38). Platelets were transfused to 85.4% of infants with severe and 64.7% of infants with moderate thrombocytopenia (P< 0.02). The gestational age of the majority of the platelet transfused neonates (49/60, 81.7%) was < 28 weeks. Mean gestational age and birth weight, and rates of severe thrombocytopenia, IVH, sepsis and mortality were comparable in transfused vs not-transfused infants with gestational age 28-32 weeks. Platelet transfused neonates with gestational age < 28 weeks had lower birth weights, were more often severely thrombocytopenic, and died more frequently than infants of a similar gestational age who were not transfused.

CONCLUSION

Platelet transfusions did not lower mortality in very premature born infants with moderate and severe thrombocytopenia during the NICU admission.

Thrombocytopenia among extremely low birth weight neonates: data from a multihospital healthcare system

OBJECTIVES

Thrombocytopenia is common in neonatal intensive care units (NICU), with 18 to 35% of patients developing this problem before hospital discharge. It might be even more common among extremely low birth weight neonates (ELBW, < or = 1000 g birth weight). However, little is known about thrombocytopenia in the ELBW population. We sought to determine the incidence, timing, causes, platelet transfusions given, and outcomes of thrombocytopenia among ELBW neonates.

STUDY DESIGN

We performed a cohort analysis of all 284 ELBW neonates born during 2003 and 2004 cared for in any of the Intermountain Healthcare level III NICUs.

RESULTS

Multiple platelet counts were obtained in all 284 (range, 4 to 441 platelet counts/patient). Of the 284, 208 (73%) had one or more platelet counts < or =150 000/microl. Most were detected during the first days of life; 80% were detected during the first week and only 20% were detected thereafter. Thrombcytopenia was more common among the smallest patients; 85% incidence among those < or =800 g, 60% among those 801 to 900 g, and 53% among those 901 to 1000 g. Platelet transfusions were given to 129 of the 208 thrombocytopenic neonates. More than 90% were given prophylactically (the patient was not bleeding). The mortality rate among those that received platelet transfusions was twice that of those that received no platelet transfusions (P < 0.01). In 48% of cases, the cause of the thrombocytopenia went undiagnosed. The most common explanations were being small for gestational age or delivered to a hypertensive mother, DIC, bacterial infection, fungal infection, and necrotizing enterocolitis, respectively.

CONCLUSIONS

We observed thrombocytopenia among ELBW neonates at a rate more than twice that reported among the general NICU population. Much remains to be discovered about the etiology and best treatments of thrombocytopenia among ELBW neonates.

Thrombopoietin level is increased in the serum of asphyxiated neonates: a prospective controlled study

BACKGROUND

Thrombopoietin (TPO) is a growth factor that controls platelet production. Despite the known association of chronic hypoxia and acute asphyxia with hematologic changes, TPO had not been studied in neonatal asphyxia.

OBJECTIVE

To assess TPO concentrations in the serum of asphyxiated and nonasphyxiated neonates, and examine any correlation with the severity of asphyxia.

DESIGN/METHODS

This prospective study was carried out on 32 asphyxiated neonates and 30 control subjects admitted at Cairo University Medical Center. Asphyxia was defined if two of the following were found: (1) Apgar score </=3 at 1 minute or </=6 at 5 minutes, (2) umbilical cord arterial pH </=7.2 combined with base deficit >/=-10 and (3) clinical evidence of perinatal asphyxia. Encephalopathy was classified clinically according to Sarnat's stages during the first day of life. Platelet count and TPO level (pg/ml) were measured at 1st, 3rd and 7th day of life.

RESULTS

: TPO measured on the first day of life did not differ between cases and controls (900.2+/-526.4 vs 726.6+/-441.9 pg/ml, p=0.2). It increased on the 3rd day of life and was significantly higher in asphyxiated infants compared to controls (1291.4+/-627.9 vs 885.5+/-400.3 pg/ml, respectively; p=0.004). This difference remained significant in a logistic regression model controlling for birth weight, sex and mode of delivery (regression coefficient=476.9+/-146.8; p=0.002). In asphyxiated infants (n=32), encephalopathy was classified as mild (n=17), moderate (n=10) and severe (n=5). TPO correlated with the degree of clinical severity on the 7th day of life (r=0.59, p=0.003). TPO did not differ between survivors (n=24) and nonsurvivors (n=8) within the asphyxia group (1197.1+/-596.8 vs 1613.1+/-605.9 pg/ml; p=0.09). Platelet counts correlated negatively with TPO measured on day 1 (r=-0.415; p=0.02), day 3 (r=-0.64; p=0.001) and day 7 (r=-0.562; p=0.007).

CONCLUSIONS

TPO increased and correlated with severity of asphyxia at 3 and 7 days of life. It correlated negatively with the platelet count at all times.

Patterns of thrombocytosis and thrombocytopenia in hospitalized neonates

OBJECTIVE

We sought to identify changes in platelet (PLT) counts over time, and to evaluate the patterns of thrombocytopenia and thrombocytosis in hospitalized infants 23.8 weeks to term gestation.

STUDY DESIGN

Neonates were divided into four gestational age groups and their PLT counts were retrospectively compared for prevalence of thrombocytopenia, thrombocytosis, and associated conditions.

RESULTS

Postconceptional age, postnatal age, and sepsis (among other factors) affected PLT counts. When counts from noninfected appropriately grown infants were evaluated, the risk of thrombocytopenia and thrombocytosis were highest in the most preterm infants, and these risks changed with corrected gestational age. PLT counts increased weekly over the first 4 weeks of life for all but the most preterm infants.

CONCLUSIONS

These data characterize the incidence of thrombocytopenia and thrombocytosis across a wide range of gestational ages and show that, even in noninfected neonates, these conditions are common, and risk decreases with increasing maturity. The age-related changes in PLT patterns may reflect maturation of platelet regulation.

Pseudothrombocytopenia in a preterm neonate

Severe and prolonged thrombocytopenia is not uncommon among ill preterm infants. Pseudothrombocytopenia, which has the appearance of severe and prolonged thrombocytopenia, has not been described in this population. We observed a preterm neonate who had EDTA-independent pseudothrombocytopenia and conclude that this condition should be considered when severe and prolonged thrombocytopenia occurs in a neonate in the absence of clinical signs of platelet-type hemorrhage.

Evaluation and treatment of severe and prolonged thrombocytopenia in neonates

Thrombocytopenia is one of the most common hematologic problems in the neonatal intensive care unit (NICU). Despite its prevalence,several basic pathophysiologic questions remain unanswered. For instance, there is a lack of evidence-based guidelines for treatment,and the kinetic mechanisms (decreased platelet production,increased platelet consumption, or sequestration) responsible for most varieties of neonatal thrombocytopenia are not well defined.Moreover, a clear correlation between degree of thrombocytopenia and the resulting bleeding risk has not been demonstrated, and no transfusion-trigger studies have been conducted in neonates. As a consequence of these deficiencies in knowledge, there is great variability in platelet transfusion practices among NICUs. This article presents an overview of the evaluation of a neonate with severe thrombocytopenia and a review of current and projected therapeutic options.

Neonatal thrombocytopenia: causes and management

Neonatal thrombocytopenia is a common clinical problem. Thrombocytopenia presenting in the first 72 hours of life is usually secondary to placental insufficiency and caused by reduced platelet production; fortunately most episodes are mild or moderate and resolve spontaneously. Thrombocytopenia presenting after 72 hours of age is usually secondary to sepsis or necrotising enterocolitis and is usually more severe and prolonged. Platelet transfusion remains the only treatment. There is a need for trials to define the safe lower limit for platelet count and which neonates will benefit from treatment.

Evaluation and treatment of thrombocytopenia in the neonatal intensive care unit

Phlebotomy-induced anaemia excepted, thrombocytopenia is the most common haematological abnormality in neonatal intensive care unit (NICU) patients. Roughly one-quarter of all NICU patients and half of all sick preterm neonates develop thrombocytopenia. Whereas a large number of varied precipitating conditions has been identified, early-onset thrombocytopenia (<72 h) is most commonly associated with fetomaternal conditions complicated by placental insufficiency and/or fetal hypoxia, e.g. maternal pre-eclampsia and fetal intrauterine growth restriction. The resulting neonatal thrombocytopenia is usually mild to moderate, resolves spontaneously and requires no specific therapy. Deviation from this pattern of thrombocytopenia suggests the presence of more significant precipitating conditions. The most important of these are the immune thrombocytopenias, and every NICU should develop investigation and treatment protocols to manage these cases promptly and avoid unnecessary risk of haemorrhage. In contrast, late-onset thrombocytopenia (>72 h) is almost always associated with sepsis or necrotizing enterocolitis and the associated thrombocytopenia is severe, prolonged and often requires treatment by platelet transfusion. Unfortunately, evidence-based guidelines for platelet transfusion therapy in NICU patients are currently unavailable, making it difficult to define widely accepted thresholds for transfusion and leading to a significant variation in transfusion practice between centres.

CONCLUSION

While improving this situation remains a pressing need, the growing evidence that impaired megakaryocytopoiesis and platelet production are major contributors to many neonatal thrombocytopenias suggests that recombinant haemopoietic growth factors, including thrombopoietin and interleukin-11, may be useful future therapies to ameliorate neonatal thrombocytopenia.

Use of the bleeding time in the neonatal intensive care unit

Impairments of primary hemostasis are frequently responsible for serious bleeding in sick infants in the neonatal intensive care unit (NICU). Therefore, a rational approach to these infants with hemorrhagic manifestations, in addition to an accurate medical history, a careful physical examination and routine screening coagulation tests, may include a bleeding time. The bleeding time is the traditional in vivo test for assessing primary hemostasis. It is a useful clinical tool to detect quantitative or qualitative platelet disorders or microvascular defectiveness. Its diagnostic value in neonates is controversial, mainly owing to limited experience in executing the test, which is performed uncommonly in the NICU. Using a template device expressly adapted for neonates (Surgicutt Newborn), a small incision 2.5 mm long and 0.5 mm deep provides a standardized, reproducible and sensitive bleeding time, with minimal scarring and pain. Various hereditary or acquired maternal and neonatal diseases, as well as some antepartum medications given to the mother or drugs commonly used to treat NICU patients, such as indomethacin, ibuprofen, penicillin compounds and theophylline, can impair primary hemostasis and consequently prolong the bleeding time in neonates. Furthermore, other factors distinctive to neonates, including gestational age, the increased von Willebrand factor concentration and function, high hematocrit, the large size of erythrocytes and platelet hyporeactivity in the first 10 d of life, affect platelet-vessel wall interaction and influence the interpretation of bleeding time results in newborn infants. Because the clinical evaluation of primary hemostasis consists of complex laboratory testing, largely reserved for specialized laboratories and currently not routinely performed in newborn infants, automated bleeding time devices specifically generated to make standardized and acceptably small incisions in newborn infants have become a surrogate.

CONCLUSION

With awareness of its value and limitations, the bleeding time can be included in the baseline evaluation of neonates in the NICU, for guiding diagnosis and treatment of primary hemostatic disorders.

Thrombocytopenia in the newborn

Thrombocytopenia remains a common problem in sick newborns. A quarter of all neonates admitted to neonatal intensive care units develop thrombocytopenia, and in 20% of episodes the thrombocytopenia is severe (platelets <50 x 10(9)/L). Practical and clinically relevant classifications of neonatal thrombocytopenia have now been developed which, by highlighting the principal conditions precipitating severe thrombocytopenia (eg, sepsis, necrotizing enterocolitis, perinatal asphyxia, and the immune thrombocytopenias), aid the practicing neonatologist. Recent reviews demonstrate that many neonates with severe thrombocytopenia receive repeated platelet transfusions, although evidence of their clinical benefit is lacking, and there exists a significant variation in platelet transfusion practice between centers. These facts support the need for the development of evidence-based protocols for platelet transfusion in the newborn and stimulate continued interest in the potential of hemopoietic growth factors (, thrombopoietin and interleukin-11) to prevent or treat neonatal thrombocytopenia.

Multicenter analysis of platelet transfusion usage among neonates on extracorporeal membrane oxygenation

OBJECTIVE

Multiple platelet transfusions are invariably given to neonates on extracorporeal membrane oxygenation (ECMO), and no alternative to repeated transfusions exists. Before any alternatives, such as administration of thrombopoietic stimulators, could be contemplated, data regarding the number of platelet transfusions received by neonatal ECMO patients is needed, and the mechanisms that cause the thrombocytopenia of these patients must be better defined. As a step toward determining this, we analyzed the use of platelet transfusions in this group of neonates. We conducted a historic cohort study of neonates who were treated with ECMO to determine the number of platelet units received as a function of 1) days on ECMO, 2) medical diagnosis for which ECMO was instituted, and 3) type of ECMO used (venovenous [VV] vs venoarterial [VA]).

METHODS

We reviewed the hospital records of all neonates who were admitted to the neonatal intensive care units at Shands Children's Hospital, Arnold Palmer Hospital for Children and Women, and Tampa General Hospital and treated with ECMO between January 1, 1995, and June 30, 2000. Data were expressed as the number of platelet transfusions versus number of days on ECMO, diagnosis for which ECMO was instituted, and type of ECMO used.

RESULTS

Of the 234 ECMO patients, 81 were placed on VV, 138 were placed on VA, and 15 were converted from VV to VA. The average number of platelet transfusions received per day was 1.3 and varied by diagnosis and by type of ECMO. Neonates with meconium aspiration and sepsis required more platelet transfusions per day than neonates with other conditions. Infants who were converted from VV to VA required more transfusions per day (mean: 1.57) than did patients on VA (1.47) or VV (1.06).

CONCLUSIONS

Platelet transfusions among neonates on ECMO are dependent of their medical diagnosis; they average 1.3 transfusions per day and are higher on VA than VV ECMO.