Consistent approaches to procedures and practices in neonatal hematology

Anemia of prematurity: how low is too low?

Anemia of prematurity (AOP) is a common condition with a well-described chronology, nadir hemoglobin levels, and timeline of recovery. However, the underlying pathophysiology and impact of prolonged exposure of the developing infant to low levels of hemoglobin remains unclear. Phlebotomy losses exacerbate the gradual decline of hemoglobin levels which is insidious in presentation, often without any clinical signs. Progressive anemia in preterm infants is associated with poor weight gain, inability to take oral feeds, tachycardia and exacerbation of apneic, and bradycardic events. There remains a lack of consensus on treatment thresholds for RBC transfusion which vary considerably. This review elaborates on the current state of the problem, its implication for the premature infant including association with subphysiologic cerebral tissue oxygenation, necrotizing enterocolitis, and retinopathy of prematurity. It outlines the impact of prophylaxis and treatment of anemia of prematurity and offers suggestions on improving monitoring and management of the condition.

Transfusion in Neonatal Patients: Review of Evidence-Based Guidelines

Transfusion of red blood cells, platelets, and fresh frozen plasma in neonatal patients has not been well characterized in the literature, with guidelines varying greatly between institutions. However, anemia and thrombocytopenia are highly prevalent, especially in preterm neonates. When transfusing a neonatal patient, clinicians must take into consideration physiologic differences, gestational and postnatal age, congenital disorders, and maternal factors while weighing the risks and benefits of transfusion. This review of existing literature summarizes current evidence-based neonatal transfusion guidelines and highlights areas of current ongoing research and those in need of future studies.

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.

Platelet transfusion for neonates with thrombocytopaenia: protocol for a systematic review

INTRODUCTION

Thrombocytopaenia is one of the most common haemostatic abnormalities among neonates. It affects approximately one-quarter of neonates admitted into neonatal intensive care units and may lead to a high risk of bleeding and mortality, which are substantial causes for concern by neonatologists. Platelet transfusion (PT) is a specific treatment for thrombocytopaenia. To date, PT thresholds are diverse since the associations between low platelet count and negative outcomes are not clear. We propose this protocol for a systematic review to collect and assess evidence concerning the best PT threshold to reduce mortality, bleeding and major morbidity among neonates with thrombocytopaenia.

METHODS AND ANALYSIS

The systematic review will be performed according to the Cochrane Handbook for Systematic Review of Interventions, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement, and the Grading of Recommendations Assessment, Development and Evaluation system. Two independent researchers will perform the study selection, data extraction/coding, quality assessment and further analyses of the included studies, with disagreements being resolved by a third researcher. A systematic search of the literature will be conducted in the PubMed, Cochrane Library and Embase databases from database inception through 13 October 2020. All randomised controlled trials, cohort studies and case-control studies will be included without any restrictions regarding publication date or language. The primary outcomes will comprise in-hospital mortality and bleeding episodes. Endnote X9 and Review Manager V.5.3 software will be used to manage the selection process and statistical analysis, respectively. If the included studies are sufficient and homogeneous for any of the outcomes, a quantitative synthesis (meta-analysis) may be performed. Otherwise, we will conduct a narrative systematic review of the results.

ETHICS AND DISSEMINATION

Ethical approval is not required for this study because the data will be obtained from published studies and will not include individual patient data. The results of this study are anticipated to be published in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42020169262.

Early anemia and neonatal morbidity in extremely low birth-weight preterm infants

Background: Extremely low birth-weight (ELBW) preterm infants remain at high risk for mortality and major morbidities, and nearly all need packed red blood cell transfusions within their first weeks of life. The overall objective of this study was to assess the association between anemia at admission to neonatal intensive care unit (NICU) with the neonatal morbidity and mortality in ELBW infants.Methods: This retrospective study was conducted on 106 patients with ELBW admitted at our level III NICU from January 2006 to December 2015. The subjects were divided into two groups: (1) patients with anemia at admission and (2) patients without anemia. Their characteristics and outcomes were compared. Statistical analysis was performed using the Statistical Package for the Social Sciences software, version 24.0 (IBM New York, USA), and a value of p < 0.05 was considered statistically significant.Results: Of the 106 ELBW, 34 (32%) presented with anemia at admission and 72 (68%) without anemia. Anemia-naive presented mean hemoglobin at the admission of 12.8 ± 1.5 g/dl and nonanemic 16.8 ± 2.1 g/dl, p < .001). The anemic group presented a lower gestational age (26 ± 2 vs. 27 ± 2 SD weeks, p = .025), greater need for inotropic support (52.9 vs. 31.9%, p = .041), longer period of invasive mechanical ventilation (9 vs. 2 days, p = .012), higher FiO₂ need (0.8 vs. 0.4, p < .001), more frequent hemodynamically significant patent ductus arteriosus (HS-PDA) (64.7 vs. 41.7%, p = .006) and severe intra-periventricular hemorrhage (IPVH) (41.2 vs. 16.7%, p = 0.005). The multivariate analysis confirmed an association between anemia at admission and HS-PDA (OR = 3.2; 95% CI: 1.1-9.5, p = 0.044) and severe IPVH (OR = 3.3; 95% CI: 1.0-9.9, p = .038). In anemic infants, ionotropic support and IPVH >2 were considered independent factors for mortality.Conclusion: In this ELBW series, the presence of anemia at admission to the NICU was associated with HS-PDA and severe IPVH. Preventive strategies for early anemia must be encouraged.

Medicinal Uses of Hematopoietic Growth Factors in Neonatal Medicine

This review focuses on certain hematopoietic growth factors that are used as medications in clinical neonatology. It is important to note at the chapter onset that although all of the pharmacological agents mentioned in this review have been approved by the US Food and Drug administration for use in humans, none have been granted a specific FDA indication for neonates. Thus, in a sense, all of the agents mentioned in this chapter could be considered experimental, when used in neonates. However, a great many of the pharmacological agents utilized routinely in neonatology practice do not have a specific FDA indication for this population of patients. Consequently, many of the agents reviewed in this chapter are considered by some practitioners to be nonexperimental and are used when they judge such use to be "best practice" for the disorders under treatment.The medicinal uses of the agents in this chapter vary considerably, between geographic locations, and sometimes even within an institutions. "Consistent approaches" aimed at using these agents in uniform ways in the practice of neonatology are encouraged. Indeed some healthcare systems, and some individual NICUs, have developed written guidelines for using these agents within the practice group. Some such guidelines are provided in this review. It should be noted that these guidelines, or "consistent approaches," must be viewed as dynamic and changing, requiring adjustment and refinement as additional evidence accrues.

Neonatal Alloimmune Neutropenia

Neonatal alloimmune neutropenia (NAIN, NAIN or NIN) is a neutrophil blood group antagonism, analogous to hemolytic disease of the fetus and newborn (HDFN) and fetal/neonatal alloimmune thrombocytopenia (FNAIT). A limited number of prospective screening studies showed that granulocyte-specific antibodies were detectable in 0.35-1.1% of random postnatal maternal samples and that the incidence of NAIN was below 0.1%. Symptoms vary from none to mild skin infections, omphalitis or more severe infections like pneumonia, sepsis, and meningitis. Treatment of neonatal infection with antibiotics and granulocyte-colony stimulating factor is advised.

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.

Packed red blood cell transfusions as a risk factor for parenteral nutrition associated liver disease in premature infants

AIM

To determine if packed red blood cell transfusions contribute to the development of parenteral nutrition associated liver disease.

METHODS

A retrospective chart review of 49 premature infants on parenteral nutrition for > 30 d who received packed red blood cell (PRBC) transfusions was performed. Parenteral nutrition associated liver disease was primarily defined by direct bilirubin (db) > 2.0 mg/dL. A high transfusion cohort was defined as receiving > 75 mL packed red blood cells (the median value). Kaplan-Meier plots estimated the median volume of packed red blood cells received in order to develop parenteral nutrition associated liver disease.

RESULTS

Parenteral nutritional associated liver disease (PNALD) was noted in 21 (43%) infants based on db. Among the 27 high transfusion infants, PNALD was present in 17 (64%) based on elevated direct bilirubin which was significantly greater than the low transfusion recipients. About 50% of the infants, who were transfused 101-125 mL packed red blood cells, developed PNALD based on elevation of direct bilirubin. All infants who were transfused more than 200 mL of packed red blood cells developed PNALD. Similar results were seen when using elevation of aspartate transaminase or alanine transaminase to define PNALD.

CONCLUSION

In this retrospective, pilot study there was a statistically significant correlation between the volume of PRBC transfusions received by premature infants and the development of PNALD.

Early-Onset Neutropenia in Small-for-Gestational-Age Infants

BACKGROUND

Early neutropenia is more common in small for gestational age (SGA) neonates (birth weight <10th percentile) than in appropriately grown neonates. However, several aspects of this variety of neutropenia are unknown, including the duration, kinetic mechanism, and outcomes.

METHODS

Using 10 years of multihospital records, we studied SGA neonates who, during the first week after birth, had neutrophil counts <1000/μL.

RESULTS

This degree of neutropenia was more common in SGA neonates (6%, 207/3650) than in non-SGA matched controls (1%, 46/3650; P < .001). Neutrophil counts stayed below the lower reference interval for 7 days. Ratios of immature to total neutrophils were within the reference interval, suggesting reduced neutrophil production, not accelerated neutrophil use or destruction. Increased nucleated red cells at birth correlated with decreased neutrophils (P < .001). Neutropenia was not independently associated with maternal hypertensive disorders, over and above the effect of SGA. Of 201 neutropenic SGA neonates, 129 (64%) also had thrombocytopenia. Sixteen percent of neutropenic neonates were treated with recombinant granulocyte colony-stimulating factor (rG-CSF) or intravenous immunoglobulin (IVIG), with no reduction in late-onset sepsis or necrotizing enterocolitis (NEC). Regression analysis showed that neutropenia (but not thrombocytopenia in the absence of neutropenia) was independently associated with increased odds of developing necrotizing enterocolitis (odds ratio 4.01, 90% confidence interval 2.08 to 7.35, P < .001).

CONCLUSIONS

Neutropenia of SGA is a condition of 1-week duration. It is more closely associated with SGA than maternal hypertension (likely owing to neutrophil hypoproduction associated with intrauterine hypoxia), often accompanied by thrombocytopenia, not obviously improved by rG-CSF or IVIG, and associated with an increased risk for NEC.

Platelet mass index: is it a hope for reduction of platelet transfusion in NICU?

OBJECTIVE

Thrombocytopenia is a very common problem in neonatal intensive care unit whose only specific treatment is platelet (PLT) transfusion which has well-known risks. Our aim is to test whether using PLT mass-based transfusion guideline would result in fewer transfusions or not.

METHODS

One hundred neonates with PLT count <100,000/μl were randomized into two groups: Group 1 (n = 50) was transfused according to PLT count-based guideline, whereas Group 2 (n = 50) was transfused according to PLT mass-based guideline. Subjects receiving one or more PLT transfusions and total number of PLT transfusions, hemorrhages, morbidity and mortality in both groups were recorded.

RESULTS

Demographic characteristics, PLT counts of the infants and clinical conditions associated with thrombocytopenia in both groups were not different. There was no reduction in the number of subjects receiving PLT transfusions (54% in Group 1, 50% in Group 2; p = 0.69) and in the number of PLT transfusions per infant (0.82 ± 1.13 versus 0.8 ± 1.23; p = 0.95). There was also no difference with respect to bleeding, morbidity and mortality between the groups.

CONCLUSION

Transfusion according to PLT mass or PLT count-based guideline does not seem to influence number of transfusions or the number of infants who were transfused.

Why do four NICUs using identical RBC transfusion guidelines have different gestational age-adjusted RBC transfusion rates?

OBJECTIVE

To compare neonatal red blood cell (RBC) transfusion rates in four large Intermountain Healthcare NICUs, all of which adhere to the same RBC transfusion guidelines.

STUDY DESIGN

This retrospective analysis was part of a transfusion-management quality-improvement project. De-identified data included RBC transfusions, clinical and laboratory findings, the anemia-prevention strategies in place in each NICU, and specific costs and outcomes.

RESULT

Of 2389 NICU RBC transfusions given during the 4-year period studied, 98.9 ± 2.1% (mean ± S.D.) were compliant with our transfusion guidelines, with no difference in compliance between any of the four NICUs. However, RBC transfusion rates varied widely between the four, with averages ranging from 4.6 transfusions/1000 NICU days to 21.7/1000 NICU days (P < 0.00001). Gestational age-adjusted transfusion rates were correspondingly discordant (P < 0.00001). The lower-transfusing NICUs had written anemia-preventing guidelines, such as umbilical cord milking at very low birth weight delivery, use of cord blood for admission laboratory studies, and darbepoetin dosing for selected neonates. Rates of Bell stage ⩾ 2 necrotizing enterocolitis and grade ⩾ 3 intraventricular hemorrhage were lowest in the two lower-transfusing NICUs (P < 0.0002 and P < 0.0016). Average pharmacy costs for darbepoetin were $84/dose, with an average pharmacy cost of $269 per transfusion averted. With a cost of $900/RBC transfusion, the anemia-preventing strategies resulted in an estimated cost savings to Intermountain Healthcare of about $6970 per 1000 NICU days, or about $282,300 annually.

CONCLUSION

Using transfusion guidelines has been shown previously to reduce practice variability, lower transfusion rates and diminish transfusion costs. Based on our present findings, we maintain that even when transfusion guidelines are in place and adhered to rigorously, RBC transfusion rates are reduced further if anemia-preventing strategies are also in place.

Management and outcome of 35 cases with foetal/neonatal alloimmune neutropenia

AIM

The aim of this study was to provide an overview of foetal/neonatal alloimmune neutropenia (FNAIN), together with advice on the clinical management.

METHODS

Neutrophil serology in the Netherlands is centralised at Sanquin Diagnostic Services. We examined FNAIN cases between January 1, 1991, and July 1, 2013, to determine the number of cases diagnosed, the relationship with human neutrophil antigen (HNA) antibody, the clinical presentation and therapeutic interventions.

RESULTS

We identified 35 FNAIN cases. The detected HNA antibodies were as follows: anti-HNA-1a (n = 7), anti-HNA-1b (n = 12), anti-HNA-1c (n = 2), anti-HNA-2 (n = 8), anti-HNA-3a (n = 1), anti-HNA-5a (n = 1) and anti-FcγRIIIb (n = 4). No infections were diagnosed in 14 neonates, and the other 21 neonates suffered from omphalitis (n = 6), urinary tract infection (n = 1), candida mucositis (n = 1), fever of unknown origin (n = 6) and sepsis (n = 7, 20%). Parity, gestational age, birthweight, neutrophil counts and antibody specificity were not significantly different for cases with, and without, infections. All the infected children were treated with antibiotics. No children died.

CONCLUSION

More than half (21) of the 35 cases of FNAIN presented with infections and most implicated were HNA-1a, HNA-1b and HNA-2. Treatment with antibiotics seemed adequate. A neonatal neutropenia workflow model for use in neonatal intensive care units is presented.

Restrictive versus liberal red blood cell transfusion thresholds in very low birth weight infants: a systematic review and meta-analysis

AIM

A systematic review was conducted to examine the effects of restrictive versus liberal red blood cell (RBC) transfusion thresholds on clinically important outcomes in very low birth weight (VLBW) infants.

METHODS

Randomised controlled trials (RCTs) of varying RBC transfusion thresholds in VLBW infants were identified by searching MEDLINE, EMBASE, CINAHL, all of the Cochrane Library and other supplementary sources. Selected studies included one of the following outcomes: total number of red blood cell transfusions, donor exposure rate, cranial ultrasonographically diagnosed brain injury, retinopathy of prematurity, bronchopulmonary dysplasia, necrotising enterocolitis or death. Studies to be included were selected by two reviewers who also assessed the risk of bias of each trial. Data extraction and analyses were independently performed by two reviewers. All data were analysed using RevMan 5.

RESULTS

Six RCTs were identified. One trial did not meet the inclusion criteria, while two had inadequate methodological quality. Pooled analysis of two trials showed that the restrictive transfusion group received a significantly lower mean number of transfusions per infant (mean difference (MD) -1.35, 95% confidence interval (CI) [-2.61, -0.09]) and donor exposure rate (MD -0.54, 95% CI [-0.93, -0.15]). No other statistically significant differences were observed.

CONCLUSION

Restrictive RBC transfusion thresholds in VLBW infants may be utilised without incurring clinically important increases in the risk of death or major short-term neonatal morbidities.

Neonatal neutropenia: what diagnostic evaluation is needed and when is treatment recommended?

Neutropenia is a relatively frequent finding in the neonatal intensive care unit, particularly in very low birth weight neonates during the first week of life. Healthy term and preterm neonates have blood neutrophil counts within the same basic range as adults, but their neutrophil function, and their neutrophil kinetics during infection, differ considerably from those of adults. Neutrophil function of neonates, particularly preterm neonates, is less robust than that of adults and might also contribute to the increase in propensity to infection. In premature infants, early-onset neutropenia is correlated with sepsis, maternal hypertension, intrauterine growth restriction, severe asphyxia, and periventricular haemorrhage, and might be associated with an increase in the incidence of early-onset sepsis, nosocomial infection, and Candida colonisation. Some varieties of neutropenia in the NICU are very common and others are extremely rare. The most common causes of neutropenia in the NICU have an underlying cause that is often evident, and require little diagnostic evaluation. Unlike, persistent neutropenia should prompt evaluation even if it is of moderate severity. The laboratory tests to consider are those that provide a specific diagnosis. The first tests that should be ordered are a blood film, a complete blood count on the mother, and, if her blood neutrophil concentration is normal, maternal neutrophil antigen typing and an anti-neutrophil antibody screen. A bone marrow biopsy can be useful in cases with prolonged, unusual, or refractory neutropenia. Various treatments have been proposed as means of enhancing neutrophil production and function in preterm infants. Both recombinant granulocyte stimulating factor and recombinant granulocyte macrophage-colony-stimulating factor have been tried with variable success. Intravenous immunoglobulin, corticosteroids, granulocyte transfusions, and gamma interferon did not show a clear adequate beneficial role for the therapy of neonatal neutropenia.

Hematological interventions in NICU care: the use of rEpo, IVIG, and rG-CSF

This article focuses on the use of rEpo, IVIG, and rG-CSF in the NICU. It discusses the most recent studies and the most definitive and clinically relevant evidence, rather than summarizing all published studies. The last section was written for NICU practice groups that choose to use any of these medications and are seeking a consistent approach for doing so. The section provides the author's approach to the use of rEpo, IVIG, and rG-CSF, revealing personal preferences, interpretations, and experiences, and is based on the dictum, "if you are going to use it, use it the same way each time."

Alloimmune neonatal neutropenia and neonatal isoerythrolysis in a Thoroughbred colt

A 3-day-old Thoroughbred colt was originally presented for treatment of neonatal isoerythrolysis, which was treated with a blood transfusion. However, persistent neutropenia was observed despite the absence of detectable infection. Subsequently, a granulocyte agglutination test was performed by incubating the colt's neutrophils with the mare's serum; results were positive, leading to a clinical diagnosis of alloimmune neonatal neutropenia. The diagnosis was further supported via flow cytometric analysis. The colt was hospitalized and treated prophylactically with antimicrobials and 4 separate doses of recombinant human granulocyte colony-stimulating factor (rhG-CSF; 1.4-3.5 µg/kg, subcutaneously) in attempts to maintain the neutrophil count within reference intervals over a 4-week period. The colt's neutrophil count increased after administration of rhG-CSF and eventually stabilized within reference intervals by day 20. The colt maintained normal neutrophil counts after discharge and was reportedly healthy at 6 months of age. Alloimmune neonatal neutropenia should be considered in foals with persistent neutropenia in the absence of infection. Alloimmune neonatal neutropenia can be treated with prophylactic antimicrobials combined with rhG-CSF with a favorable outcome.

Neonatal red blood cell transfusions: searching for better guidelines

BACKGROUND

Packed red blood cell (RBC) transfusions are often administered to patients in the neonatal intensive care unit. The purpose of this study was to determine whether current blood transfusion guidelines are as useful as care givers' perception in identifying patients in need of a packed RBC transfusion.

DESIGN AND METHODS

Health care providers were asked to complete a pre- and post-transfusion survey on neonates receiving a packed RBC transfusion. These patients were divided into three groups based on reasons for transfusion: (i) guidelines; (ii) care-givers' perceptions of need for packed RBC transfusion; or (iii) both. These three groups were further subdivided into two cohorts according to whether they had a clinical improvement or not. Demographic data and clinical variables were compared between the groups.

RESULTS

Seventy-eight care-givers were surveyed. Eighteen patients (23%) were transfused based on guidelines, 36 (46%) based on care givers' perception and 24 (31%) based on both. Neonates transfused based on guidelines alone were more likely to have received the transfusion in the first week of life, had a higher pre-transfusion haematocrit, were less symptomatic and had a higher trend to require mechanical ventilation. Neonates transfused based on caregivers' perception were more likely to be on non-invasive ventilatory support and were more symptomatic. Neonates who improved after a transfusion had a lower pre-transfusion haematocrit (p=0.02), were more symptomatic (p=0.01) and were more likely to be on non-invasive ventilatory support (p=0.002) when compared to the group without a clinical improvement. The group without improvement had an increase in oxygen requirement (+2.8±6.4) after the transfusion (p=0.0004). Tachycardia was the most sensitive predictor of a benefit from packed RBC transfusion [OR 6.48: p=0.005].

DISCUSSION

Guidelines on when to transfuse stable growing neonates with packed RBC should be re-evaluated to include more care giver judgement and perhaps be more restrictive for critically ill neonates.

Platelet transfusion in the neonatal intensive care unit: benefits, risks, alternatives

Platelet transfusions were introduced into clinical medicine about 60 years ago when they were shown to reduce the mortality rate of patients with leukemia who were bleeding secondary to hyporegenerative thrombocytopenia. In modern neonatology units, platelet transfusions are integral and indeed lifesaving for some neonates. However, the great majority of platelet transfusions currently administered in neonatal intensive care units (NICUs) are not given in the original paradigm to treat thrombocytopenic hemorrhage, but instead are administered prophylactically with the hope that they will reduce the risk of spontaneous bleeding. Weighing the risks and benefits of platelet transfusion, although imprecise, should be attempted each time a platelet transfusion is ordered. Adopting guidelines specific for platelet transfusion will improve consistency of care and will also generally reduce transfusion usage, thereby reducing costs and conserving valuable blood bank resources. Initiating specific programs to improve compliance with transfusion guidelines can further improve NICU transfusion practice.

The complete blood count

THE COMPLETE BLOOD COUNT (CBC) is one of the more common laboratory tests ordered during the neonatal period. The CBC may be obtained to evaluate for anemia, infection, and thrombocytopenia.1 The test offers a wealth of clinical information about the hematopoietic system, including erythrocyte, leukocyte, and thrombocyte values. Establishing normal neonatal ranges has been difficult because blood has not been drawn on healthy neonates of similar ages.2 Reference ranges that consist of the 5th to 95th percentile compiled from various studies have been used to approximate normal neonatal values.3 A variety of factors such as sample site, timing of the sample, gestational age, and the neonate’s degree of health can affect the CBC.1 Therefore, the astute practitioner must be able to recognize the clues and nuances of the CBC to guide the diagnostic assessment.4

Can we cut the incidence of necrotizing enterocolitis in half--today?

Necrotizing enterocolitis (NEC) is a common gastrointestinal emergency of neonates. Population studies estimate the incidence of NEC at between 0.3 and 2.4 per 1000 live births in the United States, with a predominance of cases among preterm neonates born at the earliest gestational ages. The disease burden of NEC includes an overall disease-specific mortality rate of 15-20%, with yet higher rates in those of earliest gestations. The NEC burden also includes an increase in hospital costs approximating $100,000/case, as well as severe late sequellae including parenteral nutrition-associated liver disease and short bowel syndrome. Differentiating NEC from other forms of acquired neonatal intestinal disease is critical to assessing the success of NEC prevention strategies. Promising new prevention strategies are now being tested; one such is prophylactic heparin-binding epidermal growth factor-like growth factor (HB-EGF) administration. However, two prevention strategies have already been shown in meta-analyses to reduce the incidence of NEC, but we speculate that these are not being fully utilized. They are; 1) implementing a written set of feeding guidelines (also called standardized feeding regimens) for newborn intensive care unit (NICU) patients, and 2) implementing programs to increase the availability of human milk for patients at risk of developing NEC.

Platelets, frozen plasma, and cryoprecipitate: what is the clinical evidence for their use in the neonatal intensive care unit?

Transfusion of blood components such as platelets, frozen plasma, and cryoprecipitate is a common practice in the neonatal intensive care unit. Although it is intuitive that these components would be transfused in the context of bleeding, their use in neonatology has often been on a prophylactic basis. Due to a lack of consensus guidelines regarding indications for transfusion, however, the neonatologist is left to his/her opinion as to when to transfuse. This article seeks to review the available evidence regarding the use of platelets, frozen plasma, and cryoprecipitate in neonates, as well as the risks associated with the administration of these products.

Platelet transfusion practices among neonatologists in the United States and Canada: results of a survey

OBJECTIVE

In the absence of scientific evidence, current neonatal platelet transfusion practices are based on physicians' preferences, expert advice, or consensus-driven recommendations. We hypothesized that there would be significant diversity in platelet transfusion triggers, product selection, and dosing among neonatologists in the United States and Canada.

METHODS

A Web-based survey on neonatal platelet transfusion practices was distributed to all members of the American Academy of Pediatrics Perinatal Section in the United States and to all physicians listed in the 2005 Canadian Neonatology Directory.

RESULTS

The overall response rate was 37% (1060 of 2875). In the United States, 37% (1007 of 2700) responded, of which 52% practiced at academic centers. Thirty percent (53 of 175) of Canadians responded, of whom 94% practiced at academic centers. As hypothesized, there was significant practice diversity in both countries. The survey also revealed that platelet transfusions are frequently administered to nonbleeding neonates with platelet counts of >50 x 10(9)/L. This practice is particularly prevalent among neonates with specific clinical conditions, including indomethacin treatment, preceding procedures, in the postoperative period, or with intraventricular hemorrhages.

CONCLUSIONS

There is great variability in platelet transfusion practices among US and Canadian neonatologists, suggesting clinical equipoise in many clinical scenarios. Prospective randomized clinical trials to generate evidence-based neonatal platelet transfusion guidelines are needed.

The use of blood products in perinatal medicine

Fetal and neonatal medicine is a field with many new procedures and techniques. An increasing number of centres worldwide give intrauterine transfusions, which are considered to be standard-of-care treatment for severe fetal anaemia. The survival of very prematurely born neonates, in particular of a gestational age of <28 weeks, has greatly improved over the last decade but almost all these children need transfusions. Although in many cases such blood transfusions are life saving, randomized, controlled studies investigating appropriate indications, transfusion volume and type of blood product have not been performed. Most of the protocols used are expert based.

Adherence to NICU transfusion guidelines: data from a multihospital healthcare system

OBJECTIVE

We critically reviewed every NICU blood component transfusion (packed erythrocytes, platelets, frozen plasma (FP) and cryoprecipitate) administered during a one-year period. This was done to determine the proportion of transfusions given out of compliance with the Intermountain Healthcare transfusion guidelines, and to look for patterns of non-compliance that could be addressed by quality improvement measures.

STUDY DESIGN

A detailed review was made of every transfusion administered to patients with a date of birth of 1 January 2006 through 31 December 2006, in any of three level III, perinatal-center-associated NICUs within Intermountain Healthcare.

RESULT

During 2006 the three NICUs cared for 1759 neonates. Seventeen percent of these received one or more (median 3) erythrocyte transfusions, 4% received one or more (median 3) platelet transfusions, 6% received one or more (median 1) FP infusions and 2% received cryoprecipitate (median 1 dose). Seventy percent of the erythrocyte transfusions were given in compliance with the guidelines, as were 69% of the platelet transfusions, 65% of the FP transfusions and 94% of the cryoprecipitate administrations. Patients who received large numbers of transfusions were more likely to receive transfusion that violated the guidelines. Forty-five percent of patients who received 1 to 3 transfusions received all transfusions within guidelines. However, only 18% of patients who received 4 to 10 transfusions received all within guidelines. No patient who received >10 transfusions received all within the guidelines. Erythrocyte transfusions given early in the hospital course were likely to be within guidelines; 72% (588/818) in the first 29 days were compliant with guidelines, but compliance fell to 61% (144/237) for transfusions administered after 29 days (P=0.002). About half of the platelet transfusions given early in the hospital course were in violation of guidelines, but after day 9, 83% of platelet transfusions were compliant with guidelines (P=0.000).

CONCLUSION

Opportunities exist in our healthcare system to improve compliance with our transfusion guidelines. Such opportunities are greatest among neonates receiving multiple transfusions, among those receiving erythrocyte transfusions late in their NICU course and among those receiving platelet transfusions early in their NICU course.

Advances and controversies in neonatal ICU platelet transfusion practice

Some of the platelet transfusions currently given to NICU patients are unnecessary and convey no benefits. Although ordered with good intentions, unnecessary platelet transfusions carry known and unknown risks. Identifying and eliminating any unnecessary platelet transfusions in NICUs would be a step toward better care, lower costs, and more careful preservation of blood component resources. A renewed interest in platelet transfusion studies is needed, if essential data is to be gathered to improve NICU platelet transfusion practice. Retrospective studies can be of value: for instance, seeking associations between bleeding events and platelet counts can suggest the possibility of cause and effect relationships. Such studies might identify approximate platelet count levels that convey high hemorrhagic risk and might help focus future prospective trials. Prospective indirect studies also can be of value, for instance, measuring the template bleeding time and the PFA-100 closure time as a function of platelet count and perhaps as a function of circulating platelet mass, and would provide new information with relevance to platelet transfusion benefits. Such studies might give a better awareness of how low the platelet count can fall before platelet plug formation is impaired. It seems inescapable, however, that new, multicentered, randomized, prospective studies are needed, where NICU patients are assigned different platelet transfusion triggers and then carefully tracked for bleeding events and long-term neurodevelopmental outcomes. Only that type of study is likely to generate the evidence base needed for widespread implementation of improvements in NICU platelet transfusion practice.

Implementing feeding guidelines for NICU patients<2000 g results in less variability in nutrition outcomes

BACKGROUND

We devised a consistent approach to instituting and advancing enteral nutrition among neonatal intensive care unit (NICU) patients<2000 g birth weight. We then assessed variability in feeding-related outcomes during a period before (period 1) vs after (period 2) implementing these guidelines.

METHODS

Using data from period 1 vs period 2, we statistically compared the equivalence of variance, focusing on certain feeding-related outcomes. Specific outcomes we chose to examine were (1) day of life when the first enteral feedings were given, (2) number of days during the entire hospitalization when no feedings were given, (3) number of days parenteral nutrition (PN) was administered, and (4) day of life when feedings of 80 mL/k/d and 100 kcal/k/d enteral were achieved.

RESULTS

Fifty-eight patients<2000 g were admitted to the NICU in period 1, of which 56 survived to discharge home. In period 2, 68 patients<2000 g were admitted and 66 survived to discharge. Demographic features of the patients in periods 1 and 2 did not differ. In both periods, feedings were begun on a median of day 1. However, in period 1 the range was from day 0 to day 24, and in period 2, the range was from day 0 to day 6 (equivalence of variance p<.001). After feedings were initiated, they were withheld for a median of 2 days (range, 0-23) during the remainder of the hospitalization in period 1 vs a median of 1 day (range, 0-12) in period 2 (p<.001). During period 1, PN was used for a median of 10 days (range, 0-72) vs 7 (range, 0-47) in period 2 (p=.001). During period 1, more variability occurred in the day of life when 80 mL/k/d and 100 kcal/k/d were achieved (both p<.001). No differences were seen in necrotizing enterocolitis, intestinal perforation, mortality, or length of hospital stay.

CONCLUSIONS

Implementing feeding guidelines was associated with significantly less variability in feeding-related outcomes. We speculate that this is a reflection of better feeding tolerance, which resulted from a more consistent approach to initiating and advancing enteral feedings.

Myocardial adaptation to anemia and red blood cell transfusion in premature infants requiring ventilation support in the 1st postnatal week

BACKGROUND

Although transfusion practice in very premature infants is becoming more restrictive, little is known about myocardial adaptation to anemia during the 1st postnatal week.

OBJECTIVES

To determine the central hemodynamic effects of anemia and red blood cell transfusion in very preterm infants undergoing intensive care.

METHODS

Twenty-nine neonates of less than 30 weeks gestational age were treated for respiratory distress syndrome, following a strict protocol. Echocardiographies were performed at the 4th and 6th postnatal days, which corresponded to, respectively, just before and 48 h after an erythrocyte transfusion of 15 ml/kg in the 12 anemic infants.

RESULTS

Anemic infants had increased stroke volume [2.1 (1.8-2.3) vs. 1.5 (1.3-1.6) ml/kg] and left ventricular (LV) output [312 (271-345) vs. 206 (177-240) ml/min/kg]. The relationship of the heart rate-corrected velocity of circumferential fiber shortening to LV end-systolic meridional wall stress indicated a higher contractile state in the anemic infants, with a higher y-intercept (p = 0.03) and a steeper slope (p = 0.05) of the regression line than in the nonanemic patients. Posttransfusion, the stroke volume, LV output, shortening fraction, and contractile state decreased to the values observed in the nonanemic infants.

CONCLUSIONS

Myocardial contractility was a major component of the circulatory adjustments in the anemic premature infants requiring ventilation support in the early neonatal period. Changes in LV performance associated with anemia were reversed by transfusion with no detrimental effect on right ventricular function, LV preload or the respiratory status of these patients.

Low blood neutrophil concentrations among extremely low birth weight neonates: data from a multihospital health-care system

OBJECTIVE

A blood neutrophil concentration < 1000/microl has been reported to occur in about 8% of neonatal intensive care unit (NICU) patients, at some time during their hospital stay. However, the incidence of this finding among extremely low birth weight (ELBW) neonates (< 1000 g birth weight) is not known. Using data from four NICU's in one health-care system, we sought to estimate the incidence, timing, causes, severity and duration of neutrophil counts < 1000/microl among ELBW neonates. We also tabulated the treatments used for this condition and associations with mortality.

METHODS

We performed an historic cohort analysis of all ELBW neonates born during the 36-month period, 1 July 2002 to 30 June 2005, cared for in the four Intermountain Healthcare level III NICU's.

RESULTS

Three hundred and thirty-eight ELBW neonates were the subjects of the analysis. Complete blood cell counts (CBCs) were obtained in all (range, 1 to 123 CBCs/patient). Thirty-eight percent (128/338) had one or more neutrophil counts < 1000/microl. In 57% the low neutrophil count persisted for < 24 h; in 43% it persisted for 1 to 7.5 days. Most of the cases (74%) were detected during the first 3 days of life. Twenty-two percent of cases were not detected until after the first week. Low neutrophil counts were more common among the smallest patients, with a 63% incidence in those < or = 500 g, 44% in those 501 to 600 g and 34% in those 801 to 999 g. When low neutrophil counts were recognized during the first 3 days of life, the patients were typically either small for gestational age (SGA; weight < 10th percentile for gestational age) or born after pregnancy-induced hypertension (PIH) (68%), or had early-onset bacterial infection (6%). When recognized after the first 3 days, the patients typically had necrotizing enterocolitis (31%) or a nosocomial bacterial infection (19%). Alloimmune mechanisms were not tested for in any of the cases. No cause for the low counts was identified among 35% of the neutropenic patients. Intravenous immunoglobulins was administered to 28% of cases, and 100% of these were given according to our written guidelines. Recombinant granulocyte-colony stimulating factor was administered to 13% of cases, and 69% of these were given according to guidelines. Neither the presence of low neutrophil counts nor the severity (lowest recorded count) correlated with mortality rate, except in proven early-onset sepsis.

CONCLUSIONS

We observed low neutrophil counts among ELBW neonates at a rate five times that reported in the general NICU population. Most cases were present in the first days of life and occurred in SGA neonates or those with PIH. In over 1/3, no cause was discovered. We maintain that more consistency is needed in evaluating and treating neutropenia among ELBW neonates.

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.

Single-dose darbepoetin administration to anemic preterm neonates

OBJECTIVE

Darbepoetin is longer acting and more potent than recombinant erythropoietin (rEpo). In certain situations, preterm neonates might benefit from rEpo, and for such patients darbepoetin would require fewer doses at a lower cost. However, the proper dose and dosing interval have not been established.

STUDY DESIGN

We performed a prospective trial in two level III Neonatal Intensive Care Units. Patients <32 weeks gestation at birth, with a birth weight (BW) <1500 g, were eligible for participation if they were >21-days-old and had a hemoglobin (Hgb) concentration </or=10.5 g/dl. In all, 12 were to receive a single subcutaneous (s.c.) dose at either 1 or 4 microg/kg. Once before the dose was given, and at two preset intervals after, blood was obtained for immature reticulocyte fraction (IRF) and absolute reticulocyte count (ARC). Once before and at four preset intervals after, blood was obtained for pharmacokinetic studies.

RESULTS

The 12 subjects had BWs of 1129+/-245 g (mean+/-SD), were 29.2+/-1.2 weeks gestation at delivery, and were 43+/-12 days old with an Hgb concentration of 9.6+/-1.0 g/dl when the darbepoetin was given. Six received 1 microg/kg and six 4 microg/kg. The IRF increased (p<0.05) as did the ARC (p<0.05). The increases in IRF were somewhat greater among the 4 microg/kg recipients (P=0.06). The highest recorded concentrations of drug occurred 6 to 12 hours after administration. The combined 6 and 12 hours values were 185+/-106 mU/ml in the 1 microg/kg group vs 597+/-238 in the 4 microg/kg group (p<0.002). The t(1/2) was 26 hours (range 10 to 50). The biovailability-normalized clearance was 19 ml/hour/kg (range 5 to 54).

CONCLUSIONS

A single s.c. dose of darbepoetin given to preterm neonates accelerated effective erythropoiesis. The pharmacodynamic and pharmacokinetic findings suggest that darbepoetin dosing in neonates would require a higher unit dose/kg and a shorter dosing interval than are generally used for anemic adults.

Posttransfusion equilibration of hematocrit in hemodynamically stable neonates

OBJECTIVE

To determine whether hematocrit obtained 15 mins after blood transfusion in hemodynamically stable neonates is significantly different from that obtained after 6 hrs. We hypothesized that the hematocrit stabilizes within the first 15 mins that follow a 3-hr blood transfusion in preterm infants.

DESIGN

We prospectively studied 24 consecutive infants who received blood transfusion. Hematocrit was measured immediately before the transfusion and 15 mins and 6 hrs after the transfusion of 10 mL/kg body weight of sedimented red blood cells administered over 3 hrs. Hematocrit was measured by centrifugation of a capillary.

RESULTS

There was a significant increase in hematocrit from pretransfusion values both at 15 mins and 6 hrs. The increase in hematocrit from the pretransfusion value was identical (11%) at both 15 mins and 6 hrs.

CONCLUSION

The hematocrit obtained 15 mins after the end of a 3-hr blood transfusion in hemodynamically stable, anemic infants is indistinguishable from that obtained after 6 hrs in the same infants. Thus, if the increase of hematocrit is deemed insufficient at 15 mins after the transfusion, it is possible to complete the transfusion without exposing the patient to an additional donor.

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.

Neonatal neutrophils: the good, the bad, and the ugly

Neonates are at considerable risk for bacterial and fungal infections,due in great part to a variety of age-related impairments in neutrophil function. In addition, evidence suggests that the tendency of the most immature neonates to develop chronic inflammatory disorders is also related to neutrophil dysfunction. This article provides an overview of specific functional deficiencies of neutrophils that have been reported in neonates.

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.

Congenital neutropenia

The term "congenital neutropenia" signifies neutropenia that is present at birth. It includes a wide variety of disorders, some transient and others life long. Some varieties of congenital neutropenia are mild, with blood neutrophil concentrations below normal but not low enough to constitute a significant host defense deficiency. Other varieties of congenital neutropenia are characterized by low blood neutrophil concentrations and a predisposition to repeated infections.

Neonatal transfusion practice

Many previously widely accepted neonatal transfusion practices are changing as neonatologists become more aware of the risks to their patients of multiple blood product transfusions. Recent literature and research on neonatal transfusion practice are here reviewed, and practical guidelines and trigger thresholds for blood products commonly used in neonatal medicine are proposed.

Hemodynamic changes in anemic premature infants: are we allowing the hematocrits to fall too low?

OBJECTIVE

Currently, many nurseries allow hematocrits to fall to <21% in apparently "stable" premature infants before considering a blood transfusion. We evaluated clinical changes and hemodynamic changes by echocardiogram in "stable" anemic premature infants before, during, and after transfusion.

METHODS

"Stable" premature infants (< or =32 weeks' gestation) who were to receive transfusions (2 aliquots of 10 mL/kg packed red blood cells, 12 hours apart) were eligible for prospective enrollment. Cardiac function by echocardiography and vital signs were measured 4 times: 1 to 3 hours before and 2 to 4 hours after the initial aliquot and 4 to 7 hours and 27 to 34 hours after the second aliquot. Infants were grouped prospectively according to pretransfusion hematocrit ranges for analysis: < or =21% (low), 22% to 26% (mid), and > or =27% (high).

RESULTS

Thirty-two infants were enrolled. No differences were observed between the groups in sex, birth weight, postconceptional age, or postnatal weight at enrollment. Before transfusion, low- and mid-range groups had higher left ventricular end systolic and diastolic diameters, in comparison with high range. Low range had increased stroke volume in comparison with the high-range group. These changes persisted after transfusion. Mean diastolic blood pressure rose and peak velocity in the aorta fell in the low-range group after transfusion. Pretransfusion hematocrit was correlated with but poorly predictive of echocardiographic measurements. Infants with inappropriate weight gain had increased ventricular end diastolic diameters, consistent with congestive heart failure.

CONCLUSIONS

Apparently "stable" anemic premature infants may be in a clinically unrecognized high cardiac output state, and some echocardiographic measurements do not improve within 48 hours after transfusion. The benefits of transfusion practices guided by measures of cardiac function should be evaluated.

Effect of recombinant granulocyte colony-stimulating factor on blood neutrophil concentrations among patients with "idiopathic neonatal neutropenia": a randomized, placebo-controlled trial

OBJECTIVES

We previously described a severe, prolonged, idiopathic, but self-resolving, variety of neutropenia among preterm neonates. In the present study, we sought to assess the marrow neutrophil reserves of these patients by serially measuring blood neutrophils following the administration of recombinant granulocyte colony-stimulating factor (rG-CSF) or placebo.

STUDY DESIGN

Prospective, randomized trial of rG-CSF vs placebo for infants with "idiopathic neonatal neutropenia".

RESULTS

During 36 consecutive months, 2407 neonates were admitted to the neonatal intensive care unit; 429 weighed less than 1500 g at birth, 14 of these were later diagnosed with "idiopathic neonatal neutropenia"; 10 were enrolled in this trial. The five rG-CSF recipients had an immediate, marked increase in blood neutrophil concentration, indicating adequate rG-CSF-mobilizable marrow neutrophil reserves. This effect persisted to day 5, but counts were not different from those of the five placebo recipients on days 12 and 15.

CONCLUSIONS

Patients with "idiopathic neonatal neutropenia" have a substantial rG-CSF-mobilizable marrow neutrophil reserve. On that basis, we speculate that this variety of neonatal neutropenia does not constitute a significant deficiency in antibacterial defense.

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.

Inter-NICU variation in rates and management of thrombocytopenia among very low birth-weight infants

OBJECTIVES

To investigate variation among neonatal intensive care units (NICUs) in prevalence and management of thrombocytopenia in infants <1500 g.

STUDY DESIGN

In total 1283 infants &<1500 g admitted to six NICUs over 21 months were prospectively analyzed. Illness severity was measured by the Score for Neonatal Acute Physiology (SNAP). Platelet counts in the first 12 hours after birth and on day 3 of life were abstracted from the infants' medical records. Thrombocytopenia was determined from the lowest platelet count in each of these time periods.

RESULTS

There was variability in rates of thrombocytopenia among NICUs, even after controlling for risk factors (e.g., SNAP, small for gestational (SGA) age and maternal hypertension). One site had a high prevalence of thrombocytopenia, but the lowest percentage of infants with thrombocytopenia who received platelet transfusions. After controlling for SNAP, GA, SGA, Apgar score and incidence of thrombocytopenia, the odds of receiving platelets at this site, relative to the site with the highest transfusion rate, was 0.10 (95% CI 0.02 to 0.43).

CONCLUSIONS

This multicenter study finds a 10-fold variation among NICU in the administration of platelets to their thrombocytopenic infants that cannot be explained by presence of thrombocytopenia or illness severity.

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.

Immune-mediated neutropenia in the neonate

Alloimmune neonatal neutropenia, neonatal autoimmune neutropenia and autoimmune neutropenia of infancy have remained nebulous entities with difficulties in both clinical and laboratory identification. These disorders are reviewed in this article.

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.