Anemia of prematurity

Efficacy of recombinant erythropoietin for the late treatment of anemia of prematurity in a level IV neonatal intensive care unit: a retrospective single-center cohort study

OBJECTIVE

To describe the population to which we administered recombinant erythropoietin and to determine the effectiveness of this treatment as quantified by the change in hematocrit.

STUDY DESIGN

This retrospective chart review study included infants who received erythropoietin for the treatment of anemia of prematurity.

RESULTS

There were 132 infants representing 162 unique treatment courses included in the study. The average duration of therapy was 9 days (±7) and 6 doses (±2). The average change in hematocrit (Hct) was 6.2% (SD 3.9%, p < 0.001). Rise in Hct was associated with a higher number of rEPO doses (p < 0.001) and higher postmenstrual age (p < 0.001). In our small cohort we did not find an association between the number of rEPO doses and retinopathy of prematurity (ROP) requiring treatment.

CONCLUSION

Erythropoietin is safe and effective at treating anemia of prematurity as evidenced by a clinically and statistically significant increase in Hct from baseline.

Optimizing haemoglobin measurements in VLBW newborns: Insights from a comparative retrospective study

INTRODUCTION

Haemoglobin levels assessment is a crucial part of neonatal intensive care practice, the painful experience of repeated heel pricks and venepunctures blood sampling may negatively affect neonatal clinical course. To date the reliability of haemoglobin levels obtained by point-of-care testing (POCT) analysis if compared to standard blood cell count remains controversial.

MATERIALS AND METHODS

Retrospective study conducted on all inborn premature infants (gestational age < 32 weeks) admitted to NICU of the IRCCS Giannina Gaslini Institute during the period May 2021-April 2023. We considered blood samplings occurred within the first 28 days of life recording the laboratory haemoglobin levels (Hblab) (reference method), the point-of-care haemoglobin levels (HbPOCT) (alternative method) and the type of puncture (arterial, venous and capillary). A Bland-Altman analysis was performed to evaluate the Hb agreement, it determines the bias (mean difference between the reference and alternative methods) and limits of agreement (LOA; lower, l-LOA; upper, u-LOA) of measures. An acceptable limit of agreement was 1 g/dl according to the existing literature.

RESULTS

We considered 845 blood samplings from 189 enrolled patients. The comparison between the reference and the alternative method showed a good agreement for the capillary sampling technique with l-LOA of -0.717 (-0.776; -0.659) and u-LOA of 0.549 (0.490; 0.607), these results were not achievable with the other techniques, with LOAs over ±1 g/dl threshold (venous

CONCLUSIONS

The reliability of capillary POCT measured haemoglobin levels may reduce clinical-related costs and the number of painful experiences, with obvious positive effects on the daily neonatal life in the NICU and on the developing brain structures.

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Key Words

• Capillary sampling
• Haemoglobin
• Neurodevelopment
• Newborn
• POCT
• Procedural pain

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MESH Headings

• Infant
• Humans
• Infant, Newborn
• Retrospective Studies
• Reproducibility of Results
• Hemoglobins/analysis
• Point-of-Care Testing
• Infant, Premature

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Affiliation(s)

Andrea Calandrino Department of Neuroscience, Rehabilitation, Ophtalmology, Genetics, Maternal and Child Health, University of Genoa, 16132 Genoa, Italy; Neonatal Intensive Care Unit, IRCCS Giannina Gaslini Institute, 16147 Genoa, Italy
Carolina Montobbio Neonatal Intensive Care Unit, IRCCS Giannina Gaslini Institute, 16147 Genoa, Italy.
Irene Bonato Neonatal Intensive Care Unit, IRCCS Giannina Gaslini Institute, 16147 Genoa, Italy
Gaia Cipresso Neonatal Intensive Care Unit, IRCCS Giannina Gaslini Institute, 16147 Genoa, Italy
Francesco Vinci Department of Neuroscience, Rehabilitation, Ophtalmology, Genetics, Maternal and Child Health, University of Genoa, 16132 Genoa, Italy; Neonatal Intensive Care Unit, IRCCS Giannina Gaslini Institute, 16147 Genoa, Italy
Samuele Caruggi Department of Neuroscience, Rehabilitation, Ophtalmology, Genetics, Maternal and Child Health, University of Genoa, 16132 Genoa, Italy; Neonatal Intensive Care Unit, IRCCS Giannina Gaslini Institute, 16147 Genoa, Italy
Marcella Battaglini Department of Neuroscience, Rehabilitation, Ophtalmology, Genetics, Maternal and Child Health, University of Genoa, 16132 Genoa, Italy; Neonatal Intensive Care Unit, IRCCS Giannina Gaslini Institute, 16147 Genoa, Italy
Chiara Andreato Department of Neuroscience, Rehabilitation, Ophtalmology, Genetics, Maternal and Child Health, University of Genoa, 16132 Genoa, Italy; Neonatal Intensive Care Unit, IRCCS Giannina Gaslini Institute, 16147 Genoa, Italy
Federica Mongelli Neonatal Intensive Care Unit, IRCCS Giannina Gaslini Institute, 16147 Genoa, Italy
Paolo Massirio Neonatal Intensive Care Unit, IRCCS Giannina Gaslini Institute, 16147 Genoa, Italy
Giorgia Brigati Neonatal Intensive Care Unit, IRCCS Giannina Gaslini Institute, 16147 Genoa, Italy
Diego Minghetti Neonatal Intensive Care Unit, IRCCS Giannina Gaslini Institute, 16147 Genoa, Italy
Luca Antonio Ramenghi Department of Neuroscience, Rehabilitation, Ophtalmology, Genetics, Maternal and Child Health, University of Genoa, 16132 Genoa, Italy; Neonatal Intensive Care Unit, IRCCS Giannina Gaslini Institute, 16147 Genoa, Italy

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Dried Blood Spots in Neonatal Studies: A Computational Analysis for the Role of the Hematocrit Effect

Dried blood spot (DBS) microsampling is extensively employed in newborn screening (NBS) and neonatal studies. However, the impact of variable neonatal hematocrit (Ht) values on the results can be a source of analytical error, and the use of fixed Ht for calibration (Htcal) is not representative of all neonatal subpopulations. A computational approach based on neonatal demographics was developed and implemented in R® language to propose a strategy using correction factors to address the Ht effect in neonatal DBS partial-spot assays. A rational "tolerance level" was proposed for the Ht effect contribution to the total analytical error and a safe Ht range for neonatal samples, where the correction of concentrations can be omitted. Furthermore, an "alert zone" for a false positive or negative result in NBS was proposed, where the Ht effect has to be considered. Results point toward the use of Htcal values closely representative of populations under analysis and an acceptable level of percentage relative error can be attributed to the Ht effect, diminishing the probability of correction. Overall, the impact of the Ht effect on neonatal studies is important and future work may further investigate this parameter, correlated to other clinical variables potentially affecting results.

Using Dried Blood Spots for a Sero-Surveillance Study of Maternally Derived Antibody against Group B Streptococcus

Vaccination during pregnancy could protect women and their infants from invasive Group B Streptococcus (GBS) disease. To understand if neonatal dried blood spots (DBS) can be used to determine the amount of maternally derived antibody that protects infants against invasive GBS disease, a retrospective case-control study was conducted in England between 1 April 2014 and 30 April 2015. The DBS of cases with invasive GBS disease (n = 61) were matched with healthy controls (n = 125). The haematocrit, DBS storage temperature, freeze-thaw cycle, and paired serum/DBS studies were set up to optimise the antibody assessment. The samples were analysed using a multiplex immunoassay, and the results were assessed using parametric and nonparametric tests. Antibody concentrations were stable at haematocrits of up to 50% but declined at 75%. DBS storage at room temperature was stable for three months compared with storage from collection at -20 °C and rapidly degraded thereafter. Total IgG levels measured in DBS and paired serum showed a good correlation (r² = 0.99). However, due to suboptimal storage conditions, no difference was found in the GBS IgG levels between DBS samples from cases and controls. We have demonstrated a proof of concept that assays utilising DBS for assessing GBS serotype-specific antibodies in infants is viable. This method could be used to facilitate future large sero-correlate studies, but DBS samples must be stored at -20 °C for long term preservation of antibody.

Sepsis-related anemia in a pediatric intensive care unit: transfusion-associated outcomes

BACKGROUND

Pediatric patients with sepsis in intensive care units are at high risk of developing anemia, which might have adverse effects on their prognosis. This study aimed to evaluate the impact of red blood cell (RBC) transfusion on the outcomes of patients admitted to a pediatric intensive care unit (PICU) with sepsis.

METHODS

We conducted a prospective randomized clinical trial, enrolling 67 children, aged 2 to 144 months who were admitted to a PICU with a new episode of sepsis from November 2017 to April 2018. Patients were allocated randomly to two groups: Group 1, liberal transfusion strategy group, including 33 patients who had initial hemoglobin (Hb) between 7 or greater and less than 10 g/dL and received an RBC top-up transfusion to 12 g/dL; and Group 2, restrictive strategy group, including 34 patients who had the same Hb range and did not receive RBCs. Patients with Hb less than 7 or greater than 10 g/dL were excluded.

RESULTS

Of 33 patients who received liberal transfusions, 31 (93.94%) required ventilation, and 29 (87.88%) had multiorgan dysfunction. They had a significantly lengthier hospital stay and a higher incidence of acute respiratory distress syndrome and acute lung injury. Moreover, mortality was significantly higher in the liberal transfusion group (42.4% vs. 17.6%).

CONCLUSIONS

Compared to the restrictive transfusion strategy, liberal transfusion might be associated with a worse outcome. However, the possible role of other known and unknown confounding factors and minor protocol violations should be taken into consideration. We recommend minimizing factors worsening anemia in PICU patients to reduce the need for transfusion.

Disparities in the prevalence and risk factors of anaemia among children aged 6–24 months and 25–59 months in Ethiopia

Despite global efforts made to address anaemia, the prevalence remains high in most Sub-Saharan African countries. In Ethiopia, anaemia poses a very strong public health concern. The purpose of the present study was to examine the key risk factors related to anaemia among children aged 6–24 months (younger age group) and 25–59 months (older age group). We used the 2016 Ethiopian Demographic and Health Survey data, collected from 11 023 mothers with under five children. Ordered logistic regression modelling was used for assessing risk factors of childhood anaemia. The results suggest that the prevalence of anaemia was 72 % in the younger and 49 % in the older age groups. The risk factors for anaemia in the younger age group were morbidity (odds ratio (OR) 1⋅77; CI 1⋅21, 2⋅60), having no piped water source (OR 1⋅76; CI 1⋅07, 3⋅01) and no toilet facility (OR 1⋅60; CI 1⋅07, 2⋅38). The key risk factors for anaemia in the older age group were no micronutrient intake (OR 1⋅69; CI 1⋅23, 2⋅31), having a young mother (15–24 years old) (OR 1⋅35; CI 0⋅84, 1⋅91) and a non-working mother (OR 1⋅50; CI 1⋅15, 1⋅96). Anaemia also varied by region, place of residence and economic factors. Multiple factors contributed to the high prevalence of anaemia. Given the structural problem that the country has intervention strategies should consider the unique characteristics of regions and rural residences where the prevalence of anaemia is above the national average.

Brain oxygen saturation assessment in neonates using T2-prepared blood imaging of oxygen saturation and near-infrared spectroscopy

Although near-infrared spectroscopy is increasingly being used to monitor cerebral oxygenation in neonates, it has a limited penetration depth. The T₂-prepared Blood Imaging of Oxygen Saturation (T₂-BIOS) magnetic resonance sequence provides an oxygen saturation estimate on a voxel-by-voxel basis, without needing a respiratory calibration experiment. In 15 neonates, oxygen saturation measured by T₂-prepared blood imaging of oxygen saturation and near-infrared spectroscopy were compared. In addition, these measures were compared to cerebral blood flow and venous oxygen saturation in the sagittal sinus. A strong linear relation was found between the oxygen saturation measured by magnetic resonance imaging and the oxygen saturation measured by near-infrared spectroscopy ( R²= 0.64, p < 0.001). Strong linear correlations were found between near-infrared spectroscopy oxygen saturation, and magnetic resonance imaging measures of frontal cerebral blood flow, whole brain cerebral blood flow and venous oxygen saturation in the sagittal sinus ( R²= 0.71, 0.50, 0.65; p < 0.01). The oxygen saturation obtained by T₂-prepared blood imaging of oxygen saturation correlated with venous oxygen saturation in the sagittal sinus ( R²= 0.49, p = 0.023), but no significant correlations could be demonstrated with frontal and whole brain cerebral blood flow. These results suggest that measuring oxygen saturation by T₂-prepared blood imaging of oxygen saturation is feasible, even in neonates. Strong correlations between the various methods work as a cross validation for near-infrared spectroscopy and T₂-prepared blood imaging of oxygen saturation, confirming the validity of using of these techniques for determining cerebral oxygenation.

Impact of neonate haematocrit variability on the longitudinal relaxation time of blood: Implications for arterial spin labelling MRI

BACKGROUND AND PURPOSE

The longitudinal relaxation time of blood (T 1b) is influenced by haematocrit (Hct) which is known to vary in neonates. The purpose of this study was threefold: to obtain T 1b values in neonates, to investigate how the T 1b influences quantitative arterial spin labelling (ASL), and to evaluate if known relationships between T 1b and haematocrit (Hct) hold true when Hct is measured by means of a point-of-care device.

MATERIALS AND METHODS

One hundred and four neonates with 120 MR scan sessions (3 T) were included. The T 1b was obtained from a T 1 inversion recovery sequence. T 1b-induced changes in ASL cerebral blood flow estimates were evaluated. The Hct was obtained by means of a point-of-care device. Linear regression analysis was used to investigate the relation between Hct and MRI-derived R1 of blood (the inverse of the T 1b).

RESULTS

Mean T 1b was 1.85 s (sd 0.2 s). The mean T 1b in preterm neonates was 1.77 s, 1.89 s in preterm neonates scanned at term-equivalent age (TEA) and 1.81 s in diseased neonates. The T 1b in the TEA was significantly different from the T 1b in the preterm (p < 0.05). The change in perfusion induced by the T 1b was -11% (sd 9.1%, p < 0.001). The relation between arterial-drawn Hct and R1b was R1b = 0.80 × Hct + 0.22, which falls within the confidence interval of the previously established relationships, whereas capillary-drawn Hct did not correlate with R1b.

CONCLUSION

We demonstrated a wide variability of the T 1b in neonates and the implications it could have in methods relying on the actual T 1b as for instance ASL. It was concluded that arterial-drawn Hct values obtained from a point-of-care device can be used to infer the T 1b whereas our data did not support the use of capillary-drawn Hct for T 1b correction.

Anemia and transfusion in critically ill pediatric patients: a review of etiology, management, and outcomes

This article describes the incidence and etiology of anemia in critically ill children. In addition, the article details the pathophysiology and clinical ramifications of anemia in this population. The use of transfused packed red blood cells as a therapy for anemia in critically ill patients is also discussed, including the indications for and complications associated with this practice as well as potential reasons for these complications. Finally, the article lists some therapeutic practices that may lessen the risks associated with transfusion, and briefly discusses the use of blood substitutes.

Necrotizing enterocolitis and the role of anemia of prematurity

Necrotizing enterocolitis (NEC) is one of the most common surgical diseases of preterm infants, with significant short- and long-term morbidity and mortality. Although the etiology of NEC remains elusive, multiple factors adversely affecting the intestinal mucosal integrity of preterm infants are known to be associated with NEC. Anemia and red blood cell (RBC) transfusion-related gut injury have been shown to have strong correlation with NEC. Anemia potentially compromises mucosal integrity with subsequent poor healing, and this injury may be augmented by yet unknown factors associated with RBC transfusions. Although convincing evidence is lacking, there is a need for guidelines to keep the hematocrit within clinically and physiologically relevant limits by appropriate interventions. Further investigations need to focus on assessing the interplay between anemia, chronically hypoxemic/hypoperfused intestines, and early iron therapy or other pharmacologic approaches for prevention/treatment of anemia and RBC transfusions.

A double-blind, randomized clinical trial of the effect of omega-3 fatty acids on the oxidative stress of preterm neonates fed through parenteral nutrition

BACKGROUND/OBJECTIVES

The aim of this study was to research and draw conclusions about the effect of a parenteral nutrition (PN) fat emulsion, rich in omega-3 fatty acids, on the antioxidant markers of preterm infants, when compared with a standard fat emulsion. This was a double-blind, parallel-group study conducted in Athens, Greece, using an equal randomization method.

SUBJECTS/METHODS

Thirty-eight infants were selected using a double-blind method and a computer-generated randomization list. Both groups received PN, based on the same protocols. Group A received SMOFlipid fat emulsion, while group B received the standard fat emulsion (Intralipid). Serum levels of vitamin A, E and total antioxidant potential (TAP) were measured on days 0, 7 and 14 of PN support. Clinical and biochemical data were collected on days 0, 14 and on the day of discharge.

RESULTS

Serum levels of vitamin E and A were significantly increased in group A, while only vitamin A serum level was increased in group B on the fourteenth day (group A: vitamin E: P-value=0.002, vitamin A: P-value=0.000, group B: vitamin E: P-value=0.065, vitamin A: P-value=0.000). TAP was increased only in the intervention group (group A: P-value=0.000, group B: P-value=0.287). Mild anemia was developed in both groups, while no differences were detected in the infection rate, days of hospitalization, days of ventilator support and days of phototherapy.

CONCLUSIONS

Oxidative stress was significantly reduced in those neonates fed with omega-3 fatty acids, whereas no effect was observed in the neonates fed with standard lipids. Intervention had no effect on infants' growth and clinical outcome.

Issues in neonatal cellular analysis

Hematologic values in neonates differ significantly from those in older children and adults. Quantitative and qualitative differences are present as a reflection of the developmental changes during fetal hematopoiesis and, so, correlate with gestational age. At birth, the hemoglobin, mean corpuscular volume, and WBC counts of term newborns are significantly higher than those of older children and adults, and in preterm neonates the differences are even more pronounced. This review explores these differences and the major factors that account for them from the hematology laboratory standpoint. After a discussion of the developmental hematopoiesis and normal hematologic values in term and preterm neonates, important preanalytic factors, such as limited blood availability, effect of sampling site, and violent crying, and analytic interferences are examined. Finally, the review addresses resulting challenges in interpretation of hematologic test results in term and preterm neonates, especially issues surrounding neonatal reference intervals and critical value reporting, and suggests possible solutions.

Lack of association between iron status at birth and growth of preterm infants

OBJECTIVE

To assess the association between iron status at birth and growth of preterm infants.

METHODS

Ninety-five premature babies (26 to 36 weeks of gestational age) born from July 2000 to May 2001 in a public hospital in Rio de Janeiro, Southeastern Brazil, were followed up for six months, corrected by gestational age. Iron measurements at birth were available for 82 mothers and 78 children: hemoglobin, hematocrit, mean corpuscular volume and plasma iron. All children received free doses of iron supplement (2 mg/kg/day) during the follow-up period and up to two years of age. Multivariate linear regression analyses with repeated measurements were performed to assess factors associated to linear growth.

RESULTS

Growth was more pronounced up to 40 weeks of gestational age, increasing about 1.0 cm/week and then slowing down to 0.75 cm/week. The multivariate analysis showed growth was positively associated with birth weight (0.4 cm/100 g; p<0.001) and negatively associated with gestational age at birth (-0.5 cm/week; p<0.001). There was no association between cord iron and mother iron measurements and growth (p>0.60 for all measures). Only two children had anemia at birth, whereas 43.9% of mothers were anemic (hemoglobin <11 g/dl). Also, there was no correlation between anemia indicators of mothers and children at birth (r<0.15; p>0.20).

CONCLUSIONS

Maternal anemia was not associated with anemia in preterm infants and iron status of mothers and children at birth was not associated with short-term growth of preterm infants.

Recombinant human erythropoietin produced in milk of transgenic pigs

We have developed a line of transgenic swine harboring recombinant human erythropoietin through microinjection into fertilized one cell pig zygotes. Milk from generations F1 and F2 transgenic females was analyzed, and hEPO was detected in milk from all lactating females at concentrations of approximately 877.9+/-92.8 IU/1 ml. The amino acid sequence of rhEPO protein in the transgenic pig milk matched that of commercial rhEPO produced from cultured animal cells. In addition, an F-36 cell line, which proliferates in the presence of hEPO or commercial EPO, was induced to synthesize erythroid by extracts from tg sow milk. This study provides evidence that production of purified rhEPO from transgenic pig milk is a potentially valuable technology, and can be used as a cost-effective alternative in clinical applications as well as providing other clinical advantages.

Effects of transfusion in anemia of prematurity

The authors aimed to test the hypothesis that blood transfusions depress hematopoiesis in healthy infants with anemia of prematurity (AOP). They also set out to find markers that predict recovery from AOP. Thirty-nine premature babies underwent weekly and post-transfusion measurements of hemoglobin concentrations, reticulocyte counts (RCC), and erythropoietin levels (EPO). RCC and EPO dropped significantly 7 days after a blood transfusion but had normalized after 14 days. Elevated RCC or EPO levels were not predictive of an increase in hemoglobin. Postnatal HbFg/dL was higher in babies who had received transfusions. The authors conclude that blood transfusions depress erythropoiesis in infants with AOP and stimulate HbF synthesis but this effect is not sustained. Reticulocyte counts and erythropoietin levels are unhelpful in predicting recovery from AOP.

Therapeutic potential of stem cells in perinatal medicine

Increasing evidence suggests that stem cells have tremendous potential to facilitate repair of damaged tissue and to exert protective influences that limit the extent of damage. Their inherent capacity to respond to signals generated by damaged tissue, migrate to these regions and either replace dead tissue or deliver protection by secretion of specific growth hormones and protective factors, suggests that they might have unrivalled therapeutic potential in perinatal medicine. A further potential of stem cells is their use in gene repair strategies for genetic disorders; an application which is exceedingly interesting from a perinatal perspective. Because of the relatively small size of infants and their capacity for future growth, stem cell therapy could be more successful in newborns than in older children or adults. In practical terms, the placenta, with its large reservoir of fetal blood, offers the ideal source of autologous stem cells. This affords the opportunity for stem cells to be collected and used, either directly ex vivo or after in vitro modulation, both for disorders in the neonatal period and for those arising later in life. The organs most affected from tissue damage in the neonatal period are the brain and the lung. So far, the most promising application of stem cells might be in the treatment of neurological injury. In this review we discuss recent research findings with adult stem cell therapy and their potential use in perinatal medicine. Furthermore, specific animal models suitable to explore the patho-physiological mechanisms of stem cell transplantation after neurological injury will be discussed. This review gives an overview of basic science findings and their possible role for clinical application with regards to the therapeutic potential of stem cells in perinatal medicine. Medline was searched for journal selection in peer-reviewed journals with high impact scores, which were relevant to this topic. All articles were in English and the search was not limited by publication year. However, the oldest publication was dated 1988 (reference 1).

Growth, efficacy, and safety of feeding an iron-fortified human milk fortifier

OBJECTIVE

Survival rates for preterm infants who weigh between 501 and 1500 g at birth have continued to improve over time. In response to this continuing decrease in birth weight of surviving preterm infants, Enfamil Human Milk Fortifier has recently been reformulated to meet the nutritional requirements of these smaller, more rapidly growing infants. It now provides an increased protein level of 1.1 g/58 kJ, a decreased carbohydrate level of 0.2 g/58 kJ, and a combined linoleic and alpha-linolenic fatty acid content of 157 mg/58 kJ. As these very small preterm infants have an increased requirement for dietary iron, the fortifier has been supplemented with 1.44 mg/58 kJ of iron, an amount of iron similar to that provided in a typical iron-fortified term infant formula. An iron-fortified product obviates the need for administration of an iron supplement, a hyperosmolar-inducing intervention. The purpose of this prospective, double-blind, randomized, controlled study was to evaluate growth, safety, and efficacy in a population of very low birth weight (VLBW) preterm infants who received human milk fortified with either the reformulated iron-fortified powdered human milk fortifier test product (HMF-T) or a powdered commercially available human milk fortifier control product (HMF-C).

METHODS

Infants who weighed < or =1500 g, had a gestational age < or =33 weeks postmenstrual age, and had an enteral intake of at least 100 mL/kg per day of unfortified human milk were stratified by gender and birth weight and randomized to receive HMF-T or HMF-C product from study day 1 to study day 28, hospital discharge, or the termination of human milk feedings, whichever came first. Unless medically indicated, investigators were not to administer iron supplements from study days 1 to 14. Infants were assessed serially for growth; enteral and parenteral intake; serum chemistry and hematologic values; clinical histories, including the administration of blood transfusions; feeding tolerance; respiratory outcomes; and morbidities, including adverse events.

RESULTS

Of the 181 participating infants in this study, 96 received HMF-T and 85 received HMF-C. At randomization, there were no significant differences in infant characteristics between the fortifier groups. The percentage of participants who remained in the study for 28 days was similar between fortifier groups (57% HMF-T, 46% HMF-C). For both fortifier groups, the most frequent reasons for discontinuing the study before study day 28 were unavailability of human milk and hospital discharge. Rate of weight gain was similar between the fortifier groups (17.5 +/- 0.53 g/kg per day for HMF-T and 17.3 +/- 0.59 g/kg per day for HMF-C). Mean achieved weight, length, and head circumference were comparable between groups across the 28-day study period. Total protein intake from enteral and parenteral nutrition was significantly greater for the HMF-T fortifier group; however, this difference did not result in any difference in growth between the 2 fortifier groups. An analysis of the growth and energy intake data of a subset of the intent-to-treat population who adhered more strictly to the study feeding protocol yielded results similar to those seen for the intent-to-treat population. There were no clinically significant differences in the results of laboratory studies between the groups at study days 0, 14, and 28. Anemia of prematurity was prevalent in both study groups; by study day 28, median hematocrit levels were 27.0% (interquartile range [IQR]: 24.0%-29.6%) for the HMF-T group and 26.0% (IQR: 24.0%-31.0%) for the HMF-C group. Median ferritin levels were 77.0 ng/mL (IQR: 37-155 ng/ml) for HMF-T and 92.0 ng/mL (IQR: 33-110 ng/mL) for HMF-C. There were no significant differences between the study fortifier groups in regard to the receipt of medically indicated iron supplements on or before study day 14 or in the administration of blood transfusions before study day 0 or from study days 0 through 14. However, from study day 15 to study day 28, fewer HMF-T infants (n = 12) required a blood transfusion than did HMF-C infants (n = 20). Although the higher levels of iron in the HMF-T fortifier (1.44 mg vs 0.35 mg for HMF-C per 4 packets of powdered fortifier) did not prevent anemia per se, it did reduce the frequency of one of the most serious outcomes of anemia: the need for a blood transfusion. There was no statistically significant difference between fortifier groups in regard to feeding tolerance. Rates of suspected sepsis (26% HMF-T vs 31% HMF-C) and confirmed sepsis (5% HMF-T, 7% HMF-C) were low as were the rates of suspected necrotizing enterocolitis (NEC; 6% HMF-T and 5% HMF-C) and confirmed Bell's stage 2 or more NEC (1% HMF-T and 1% HMF-C). There were no statistically significant differences between the study fortifier groups in regard to the incidence of confirmed and suspected sepsis and NEC.

CONCLUSION

Both human milk fortifiers studied are safe, are well tolerated, and facilitate comparable good growth; however, using the iron-fortified product may reduce the need for blood transfusions in VLBW infants. The similar low rates of suspected and confirmed NEC and sepsis seen in both fortifier groups in this study refutes the premise that the inclusion of iron in fortifiers will increase the incidence of sepsis and NEC. Indeed, the incidence for NEC and sepsis for both groups in this study was lower than is reported for VLBW infants and similar to that seen for infants who are fed human milk.

Anemia in the critically ill

The anemia of critical illness is a distinct clinical entity with characteristics similar to that of chronic disease anemia. Several solutions to the processes of anemia, such as blunted erythropoietin production and erythropoietin response and abnormalities in iron metabolism have been developed. The transfusion of RBCs provides immediate correction of low hemoglobin levels, which may be of value in patients with life-threatening anemia. Avoidance of RBC and blood component transfusion, however, is becoming increasingly important as data of adverse clinical outcomes in critically ill patients become clearer. Although the optimal hemoglobin in critically ill patients is not determined, this organ system has a generous reserve. Short-term compensated anemia is tolerated well, while exogenous erythropoietin allows patients to achieve higher hemoglobin concentrations without exposure to transfused blood/blood components. A recent randomized trial enrolled over 1300 critically ill patients to receive either 40,000 units of exogenous erythropoietin or placebo. These authors found that patients randomized to erythropoietin received significantly less allogeneic RBC transfusions and had significantly greater increases in hemoglobin. Although no differences were found between groups in gross clinical outcomes (ie, death, renal failure, myocardial infarction), this study did not have the power to identify small differences in outcomes. This and other studies of exogenous erythropoietin therapy in critically ill patients clearly demonstrate that the bone marrow in many of these patients will respond to the administration of erythropoietin despite their illness, suggesting a blunted production of erythropoietin rather than a blunted response to erythropoietin. Exogenous erythropoietin therefore represents a therapeutic option for treating anemia in critical illness. Acute events in medicine and surgery often lead to many patients becoming anemic. Solutions to this process of anemia should be focused on preventing such events. Anemia after surgery represents an area for prevention. Blood conservation strategies can be performed with adequate results. Monk et al randomized 79 patients undergoing radical prostatectomy to preoperative autologous donation (PAD), preoperative exogenous erythropoietin therapy plus ANH immediately following induction of general anesthesia, and ANH alone. This study concluded that all three techniques resulted in similar hemostasis outcomes (eg, bleeding and transfusion rates), but ANH alone was the least expensive, and ANH plus exogenous erythropoietin and ANH alone resulted in a higher ICU hematocrit compared with PAD. Regardless of these prophylactic strategies, patients still become anemic after surgery or during critical illness. This acute event anemia usually is treated with RBC transfusion; however, autologous blood recovery (cell salvage systems) has been shown to be effective in patients with acute bleeding-related anemia, and this may reduce patients' exposure to allogeneic blood in these patients. There are no universally accepted treatment guidelines for managing anemia, and practice differs between clinicians, hospitals, regions, and countries. Transfusion medicine is evolving and incorporating many new pharmacological agents into the armamentarium of anemia and bleeding therapy. Accumulating evidence suggests that anemia in critically ill patients is common and correlated with poor outcomes. The management of anemia can improve outcomes; however, the optimal management of anemia is not performed universally. New approaches, continued research, and an understanding of anemia may result in more consistent and improved outcomes for critically ill patients.