Factors related to transfusion in very low birthweight infants treated with erythropoietin

[Single-donor protocol: Transfusion practices and multiple transfusion risk factors in neonatal intensive care unit]

In France since 2002, the single-donor transfusion protocol, using four pediatric units from the same adult donor's packed red blood cells (PRBCs) in multiply transfused newborns, is recommended in preterm neonates to reduce the risks of infection and alloimmunization. This protocol is controversial, however, because it causes the transfusion of stored blood, which could have adverse consequences. Before the new recommendations of the French Haute Autorité de santé (National authority for health) in 2015, we conducted a national practice survey in 63 neonatal intensive care units (NICU) and a retrospective study of the characteristics of 103 children transfused within our unit, to better target beneficiaries. The practice survey showed that 30 % of French NICUs no longer used the protocol in 2014, due to logistical or financial problems, or concerns about the transfusion of stored blood. The practices were heterogeneous. Few NICUs used a written protocol. In our NICU, the use of single-donor protocol involved the use of units stored for more than 20 days in half of the cases beginning with the third unit used. Six-term newborns were mainly transfused once, which does not seem to warrant the single-donor transfusion protocol. The use of this protocol caused the loss of 50 % of the manufactured units, which go unused. In multivariate analysis, two factors were predictive of multiple transfusion within our population of 95 premature neonates undergoing transfusion: low-term and a high Clinical Risk Index for Babies (CRIB) score. The risk of multiple transfusions would be reduced by about 15 % for each additional week of gestation and approximately 16 % per point within the CRIB score. These variables integrated into a statistical model predict the risk of multiplying transfusions. According to the ROC curve, a calculated risk higher than 50 % is the appropriate cut-off value to transfuse with the single-donor transfusion protocol. This would limit its indications, saving more than 130 pediatric units of blood for 100 transfused children. A prospective study in our department will allow internal validation of this test.

Influence of shielding TPN from photooxidation on the number of early blood transfusions in ELBW premature neonates

OBJECTIVES

The smallest premature neonates often receive blood transfusions early in life. Nonrestrictive transfusion policies are linked to deleterious outcomes. Exposure of total parenteral nutrition (TPN) to ambient light generates oxidation products associated with haemolysis in vitro. Shielding TPN from light limits oxidation. Our hypothesis was protecting TPN from light decreases haemolysis and therefore the need for early blood transfusions.

METHODS

Comparison of haemolysis between animals fed enterally and those receiving TPN, and exploratory case-control retrospective analysis of transfusion counts in premature infants receiving light-exposed or light-protected TPN. The statistical analysis was analysis of variance and longitudinal binomial regression model adjusting for potential covariables of transfusion counts.

RESULTS

In animals, TPN is associated with higher (P<0.05) haemolysis compared with enteral feeds; photoprotection induces lower peroxide load with no effect on the level of haemolysis. In premature infants, light-exposed (n=76) or light-protected (n=57) populations exhibited similar clinical characteristics. Initial haematocrit, gestational age, and index of disease severity had a significant effect on the number of transfusions. When adjusting for these covariables, photoprotection was no longer significant.

CONCLUSIONS

Even though peroxides are associated in vitro with haemolysis, shielding TPN from light to reduce infused peroxides does not significantly decrease the need for early transfusions in premature infants.

[Risk factors involved in the need for blood transfusion in very low birth weight newborns treated with erythropoietin]

OBJECTIVE

To identify and quantify risk factors related to red blood cell transfusion in premature babies weighing<1,500g who received erythropoietin (EPO). Secondly, to assess the relationship between retinopathy of prematurity and rh-EPO.

MATERIAL AND METHODS

Prospective descriptive study of infants admitted to the Reina Sofía University Hospital between January 2006 and March 2009. Infants reviewed had a birth weight<1,500g and gestational age<32 weeks. Infants were administered rh-EPO 750IU/kg/week subcutaneously 3 days/week/ 6 weeks. We used univariate and multivariate logistic regressions with PASW Statistics 18 for Windows.

RESULTS

Data were obtained from 110 infants, with a mean birth weight of 1154grs and mean gestational age of 29.3 weeks. Risk factors (OR; 95% CI) for being transfused were: male sex (4.41; 1.24-15.66), GA (1.64; 1.14-2.36, 1 week), Hb level on admission (1.45; 1.04-2.04; 1g/dl), late onset sepsis (7.75; 2.21-21.11), late onset treatment with rh-EPO (6.27; 1.22-32.35). All surgically treated infants with patent ductus arteriosus ligation or necrotizing enterocolitis needed transfusion. There is no relationship between rh-EPO administration and retinopathy of prematurity (ROP), but there was a relationship with transfusion.

CONCLUSIONS

Premature infants with the lower gestational age, being male, a lower Hb level on admission and late onset sepsis are those with the greatest risk for blood transfusion.

Erythropoietin pharmacokinetic/pharmacodynamic analysis suggests higher doses in treating neonatal anemia

BACKGROUND

The establishment of effective treatment of neonatal anemia using recombinant human erythropoietin (r-HuEPO) requires a thorough understanding of the physiology and mechanism of EPO's pharmacologic effect. The purpose of the present preclinical study in sheep was to elucidate the stimulatory effect of EPO on erythroid progenitors and their differentiation into reticulocytes useful in predicting optimal r-HuEPO dosing.

METHODS

Five young adult sheep each underwent two phlebotomies spaced 4-6 weeks apart in which their hemoglobin levels were reduced from 12 g/dL to 3-4 g/dL. Endogenous EPO levels and reticulocyte counts produced in response to anemia were sampled throughout the study and analyzed using a pharmacokinetic/pharmacodynamic (PK/PD) model.

RESULTS

The phlebotomy-induced drop in hemoglobin resulted in a increase in EPO levels, which reached a maximum of 764 +/- 55 mU/mL (mean +/- %CV) in 0.5-2.6 days. The reticulocyte counts increased from baseline values of 76.9 x 10(3) +/- 67/microL to 619 x 10(3) +/- 30/microL in 8 days. The PK/PD analysis indicated an increased maturation time for the reticulocytes (4.88 +/- 35 days) and demonstrated that the E(max) model for EPO's activation of the progenitors did not show significant effect saturation at the endogenous EPO levels reached.

CONCLUSIONS

In extrapolating from the animal pilot experiment, the present study provides a case for the use of higher r-HuEPO doses in human studies to determine if higher doses are more effective in treatment of neonatal anemia to reduce, and in some less severe cases, eliminate, the need for blood transfusions.

When to transfuse preterm babies

The physiological anaemia experienced by preterm babies is exacerbated by common care practices such as early clamping of the umbilical cord at birth and gradual exsanguination by phlebotomy for laboratory monitoring. The need for subsequent transfusion with red blood cells can be reduced by delaying cord clamping for 30-60 s in infants who do not require immediate resuscitation. The need for transfusions can be further reduced by limiting phlebotomy losses, providing good nutrition, and using standard guidelines for transfusion based on haemoglobin or haematocrit. What those guidelines should be is not clear. Analysis of two recent large clinical trials comparing restrictive and liberal transfusion guidelines leads to several conclusions. Restrictive transfusion guidelines may reduce the number of transfusions given, but there is no reduction in donor exposures if a single-donor transfusion programme is used. There is some evidence that more liberal transfusion guidelines may help to prevent brain injury, but information on the impact of transfusion practice on long-term outcome is lacking. Until further guidance emerges, transfusion thresholds lower than those used in the two trials should not be used, as there is no evidence that lower thresholds are safe.

Prediction of transfusions in extremely low-birthweight infants in the erythropoietin era

BACKGROUND

The purpose of the present paper was to detect the clinical factors most predictive of red blood cell (RBC) transfusion in extremely low-birthweight (ELBW) infants in the recombinant human erythropoietin era.

METHODS

Between 1995 and 2000, 66 ELBW infants were admitted to a level III neonatal intensive care unit. Fifty-four of 66 infants were eligible for enrollment in the present study. Infants were treated with erythropoietin 200 IU/kg per dose s.c. twice a week with 4-6 mg/kg per day iron supplement.

RESULTS

The mean gestational age and birthweight were 26.5 +/- 2.1 weeks and 776 +/- 134 g, respectively. Ten of 54 ELBW infants (18.5%) died during the first 21 days. Eight of 10 dead infants (80.0%) and 27 of 44 surviving infants (61.4%) received one or more RBC transfusions. The overall requirement for RBC transfusions in the surviving infants was 3.0 +/- 3.2 per infant/hospital course (range: 0-9) . There were significant differences in gestational weeks, birthweight, initial hemoglobin value, 5 min Apgar score, phlebotomy loss, phlebotomy loss/birthweight, duration of mechanical ventilation, duration of oxygen supplement, and incidence of both intraventricular hemorrhage and chronic lung disease between the transfused and non-transfused group. The predictive variables, initial hemoglobin level (odds ratio [OR] 2.61; 1 g/dL), birthweight (OR 3.00; 100 g), and gestational week (OR 1.89; 1 week), were found to be most predictive for transfusion on logistic regression analysis.

CONCLUSION

ELBW infants are still the population at greatest risk for repeated blood transfusions after introduction of erythropoietin treatment. If labor develops, it is often impossible to extend the pregnancy period, therefore efforts should be made to increase hemoglobin level at birth.

Measurement of transcutaneous hemoglobin concentration by noninvasive white-light spectroscopy in infants

OBJECTIVE

To compare transcutaneously spectroscopically measured hemoglobin values with venous hemoglobin values in infants.

STUDY DESIGN

Prospective study in healthy preterm and term infants who were breathing spontaneously.

RESULTS

Recordings were obtained from 85 stable infants (median gestational age at measurement: 36 weeks [range: 34-43 weeks]; median body weight: 1890 g [range: 1095-4360 g]). The spectroscopic hemoglobin values were corrected for inhomogeneous distribution of hemoglobin in the tissue. The venous and spectroscopic hemoglobin values were then compared by using the Bland-Altman method, which gave an error of <5%.

CONCLUSIONS

This pilot study could illustrate a good relation between the 2 methods for measuring hemoglobin. Larger studies are required to validate the spectroscopic method in those with conditions that affect the skin microcirculation (eg, septicemia).

Strict red blood cell transfusion guideline reduces the need for transfusions in very-low-birthweight infants in the first 4 weeks of life: a multicentre trial

BACKGROUND AND OBJECTIVES

Very-low-birthweight infants are among the most heavily transfused patients. The objective of this study was to verify if the introduction of a strict guideline would reduce the need for red blood cell transfusions in the first 4 weeks of life in these neonates.

MATERIALS AND METHODS

This was a multicentre prospective study of two cohorts of very-low-birthweight infants transfused in accordance with the recommendations of a neonatologist (Phase 1) or according to previously published guidelines (Phase 2).

RESULTS

In the first 28 days of life, 102 patients (68.5%) in Phase 1 and 117 (59.7%) in Phase 2 were transfused. The number of transfusions was 1.9 +/- 2.0 in Phase 1 and 1.4 +/- 1.6 in Phase 2 (P = 0.01). After adjusting for gestational age, blood loss and the presence of respiratory distress syndrome, the strict guideline reduced the number of transfusions in 17.6% (IC 95%-30.5% to -2.6%).

CONCLUSIONS

The strict guideline was effective in reducing erythrocyte transfusions in very-low-birthweight infants.

Randomized trial of liberal versus restrictive guidelines for red blood cell transfusion in preterm infants

OBJECTIVE

Although many centers have introduced more restrictive transfusion policies for preterm infants in recent years, the benefits and adverse consequences of allowing lower hematocrit levels have not been systematically evaluated. The objective of this study was to determine if restrictive guidelines for red blood cell (RBC) transfusions for preterm infants can reduce the number of transfusions without adverse consequences.

DESIGN, SETTING, AND PATIENTS

We enrolled 100 hospitalized preterm infants with birth weights of 500 to 1300 g into a randomized clinical trial comparing 2 levels of hematocrit threshold for RBC transfusion.

INTERVENTION

The infants were assigned randomly to either the liberal- or the restrictive-transfusion group. For each group, transfusions were given only when the hematocrit level fell below the assigned value. In each group, the transfusion threshold levels decreased with improving clinical status.

MAIN OUTCOME MEASURES

We recorded the number of transfusions, the number of donor exposures, and various clinical and physiologic outcomes.

RESULTS

Infants in the liberal-transfusion group received more RBC transfusions (5.2 +/- 4.5 [mean +/- SD] vs 3.3 +/- 2.9 in the restrictive-transfusion group). However, the number of donors to whom the infants were exposed was not significantly different (2.8 +/- 2.5 vs 2.2 +/- 2.0). There was no difference between the groups in the percentage of infants who avoided transfusions altogether (12% in the liberal-transfusion group versus 10% in the restrictive-transfusion group). Infants in the restrictive-transfusion group were more likely to have intraparenchymal brain hemorrhage or periventricular leukomalacia, and they had more frequent episodes of apnea, including both mild and severe episodes.

CONCLUSIONS

Although both transfusion programs were well tolerated, our finding of more frequent major adverse neurologic events in the restrictive RBC-transfusion group suggests that the practice of restrictive transfusions may be harmful to preterm infants.

Oral iron supplementation in preterm infants treated with erythropoietin

BACKGROUND

It is not known whether a moderate dose of oral iron supplementation would further enhance erythropoiesis in recombinant human erythropoietin (EPO)-treated very low-birthweight (VLBW) infants.

METHODS

In total, 24 preterm infants with birthweights 750-1499 g were enrolled at the age of 14-28 days to receive 400 IU/kg per week EPO subcutaneously for 8 weeks. The infants were randomly allocated either to receive oral iron supplementation 4 mg/kg per day or to serve as controls.

RESULTS

Hemoglobin and the absolute reticulocyte count in the iron supplementation and the control groups remained identical throughout the study period, whereas serum ferritin was significantly lower in the control group at study exit and follow up. Rates of treatment success (no need for transfusion and hemoglobin never below 8 g/dL) also did not differ between the groups.

CONCLUSIONS

In this study we did not find a clear advantage in a moderate dose of oral iron supplementation on erythropoiesis in EPO-treated VLBW infants. Whether a higher dose would lead to enhanced erythropoiesis remains to be answered.

[Recombinant human erythropoietin: analysis of a policy of treatment in an hospital based population of very-low-birthweight infants]

AIM OF THE STUDY

To evaluate a policy of treatment with human recombinant erythropoietin (rhEPO) and to describe factors related to red blood cell transfusions (RBCTs) in treated neonates.

STUDY

Prospective, observative study.

PATIENTS AND METHODS

One-hundred and sixty-five neonates with gestational age (GA) < 30 weeks and/or birthweight < 1000g admitted between may 1998 and october 1999. Ninety were excluded (congenital malformations n = 6, deaths n = 16, referral to a general hospital before discharge n = 67, ECMO n = 1). Data about the characteristics of the population, the severity of the neonatal period, hemoglobin at birth, blood loses, treatment with rhEPO, number of red blood cells transfusions (RBCTs) and donors were recorded in all infants.

RESULTS

Thirty-eight in seventy-five (51%) neonates received 112 blood transfusions. Eighty-eight were prescribed after day 15. In most of the cases (n = 68), RBCTs were done according to the protocol. In 20 cases (23%) infants were transfused during a late-onset infection. No difference was observed between the non-transfused (group I) and the transfused neonates (group II) with regards to the drug administration: first dose on day 3 +/- 2, number of injections (17 +/- 4 vs 18 +/- 1, ns). The start of oral supplementation with iron was late (12j +/- 8 vs 19j +/- 10, ns). Infants in group II had a lower birthweight (850 +/- 240 vs 1050 +/- 160 g, p < 0,01) for a similar GA (28 +/- 1SA vs 28 +/- 2SA, ns) in association with an increased number of small for date babies (p = 0.03). Antenatal steroïds administration (89 vs 74%, ns), administration of surfactant (59 vs 81%, ns) were similar in the two groups. The Clinical Risk Index for Babies was higher in group II: 5 +/- 3 vs 2 +/- 1 (p < 0,001) as was the duration of oxygen delivery (53 +/- 44 vs 14 +/- 20 days, p < 0,01) and postnatal administration of corticosteroïds ( 38% vs 3%, p < 0.01).

CONCLUSION

The quality of iron administration, RBCTs and the limitation of donors could be improved in our population. Transfusions among neonates born before 30 weeks and/or with a birthweight of less than 1000 g and treated with rhEPO are associated with intrauterine malnutrition and a worse clinical condition on admission. Early identification of at risk neonates could improve prevention of RBCTs and the efficacy of rhEPO administration to preterm infants.

Iron status and the treatment of the anemia of prematurity

Many unanswered issues regarding rhEPO therapy in prematurity remain, including which premature infants best respond to rhEPO, what the long-term effect of decreased erythrocyte transfusions is, how nutritional supplementation optimizes the effect of rhEPO, whether or not rhEpo therapy causes iron deficiency later in life, and whether or not it is safe to supplement with parenteral iron. Further study of rhEPO therapy and iron status in prematurity is necessary.

Glucose monitoring with long-term subcutaneous microdialysis in neonates

BACKGROUND

Microdialysis is a new approach for continuous monitoring of small molecules in the extracellular space, and hypoglycemia is a common problem in neonatal intensive care. The objective of this study was to evaluate subcutaneous microdialysis for long-term glucose monitoring in neonatal intensive care. We determined the relative recovery of the microdialysis system in vitro and in vivo, the stability of the relative recovery in vivo during long-term microdialysis, and the correlation between blood and dialysate concentrations of glucose and urea. Furthermore, we evaluated the sensitivity and specificy of subcutaneous microdialysis for the diagnosis of hypoglycemia.

PATIENT AND METHODS

Thirteen infants (10 neonates) with gestational ages of 30.2 to 45.6 weeks were investigated by microdialysis of subcutaneous adipose tissue and blood sampling. Subcutaneous microdialysis was performed for a median (range) duration of 9 (4-16) days.

RESULTS

The application was safe, even in extremely low birth weight infants (<1000 g) with scanty subcutaneous adipose tissue. The mean +/- standard deviation of the relative recovery in vitro was 101 +/- 3% for glucose and 100 +/- 2% for urea. Using urea as the internal standard, the mean relative recovery in vivo was 96.4 +/- 12.7% at the beginning and remained constant up to 16 days. The correlation between microdialysate and blood was significant for glucose (r = 0.88) and urea (r = 0.98). Subcutaneous microdialysis allowed the detection of asymptomatic hypoglycemias. The diagnostic sensitivity of a dialysate glucose </=2.9 mM to predict a blood glucose level </=2.8 mM was 92.3%, with 88.1% specificy. The positive predictive value with a 13.4% prevalence of a blood glucose </=2.8 mM was 54.5%, with a negative predictive value of 98.7% and an accuracy of 88.7%.

CONCLUSIONS

Subcutaneous microdialysis is a safe method, well suited for long-term glucose monitoring in neonates during intensive care. Subcutaneous microdialysis can be used to reduce blood loss and painful stress resulting from diagnostic blood sampling in high-risk neonates.

Hematocrit correlates well with circulating red blood cell volume in very low birth weight infants

Although circulating red blood cell (RBC) volume is a better measure of total body oxygen delivering capacity than hematocrit (HCT), circulating RBC volume is more difficult to measure. Thus, the HCT is often used in RBC transfusion decisions. However, several previous studies of low birth weight infants have reported that the correlation between HCT and circulating RBC volume is poor. Using a robust nonradioactive method based on in vivo dilution of biotinylated RBC enumerated by flow cytometry, the present study reexamined the correlation between HCT and circulating RBC volume in very low birth weight infants. Venous and capillary HCT levels were compared with circulating RBC volume measured using the biotin method. Twenty-six stable very low birth weight infants with birth weights less than 1300 g were studied on 43 occasions between 7 and 79 d of life. Venous HCT values correlated highly with circulating RBC volume (r = 0.907; p < 0.0001). However, the mean 95% confidence limits for prediction of circulating RBC volume from venous HCT (the average error of prediction) was +/-13.4 mL/kg. The correlation between HCT and circulating RBC volume is strong in older stable very low birth weight infants. However, clinically important uncertainty exists in estimating circulating RBC volume and the associated RBC transfusion needs of an individual infant based on venous HCT. Because direct measurement of circulating RBC volume is not yet practical, the HCT (or the blood Hb concentration) remains the best available indirect indicator.

Red blood cell transfusions in very and extremely low birthweight infants under restrictive transfusion guidelines: is exogenous erythropoietin necessary?

OBJECTIVE

To examine the number and volume of red blood cell transfusions (RBCTs) in very and extremely low birthweight infants under restrictive red blood cell transfusion guidelines without erythropoietin administration, and to compare the results with those reported in similar infants receiving erythropoietin.

METHODS

From April 1996 to June 1999, all RBCTs given to infants with a birth weight of less than 1500 g were prospectively recorded. Data on RBCT combined with erythropoietin treatment and RBCT guidelines were extracted from four prospective randomised trials of erythropoietin for anaemia of prematurity.

RESULTS

When the restrictive RBCT guidelines were followed, the number of RBCTs and volume transfused were similar to those reported during erythropoietin administration.

CONCLUSIONS

RBCT guidelines may have a similar impact on RBCT in very low birthweight infants to the administration of erythropoietin. The effect of RBCT guidelines on RBCT frequency should be considered when evaluating the efficacy of erythropoietin administration to preterm infants.

Effect of intravenous iron supplementation on erythropoiesis in erythropoietin-treated premature infants

OBJECTIVE

To test the efficacy and safety of combining intravenous iron in amounts approximating the in utero iron accretion rate and the postnatal iron loss with erythropoietin (EPO) in very low birth weight (VLBW) infants.

METHODS

A prospective, controlled, randomized, unmasked trial lasting 21 days was performed in 29 clinically stable VLBW infants <31 weeks' gestation and <1300 g birth weight not treated with red blood cell transfusions during the study period. Mean (+/- standard error of the mean) age at study entry was 23 +/- 2.9 days. After a 3-day run-in baseline period in which all participants received oral supplements of 9 mg/kg/day of iron polymaltose complex (IPC), participants were randomized to receive 18 days of treatment with: 1) oral IPC alone (oral iron group); 2) 300 U of recombinant human EPO (r-HuEPO) kg/day and daily oral IPC (EPO + oral iron group); 3) 2 mg/kg/day of intravenous iron sucrose, r-HuEPO, and oral iron (intravenous iron + EPO group). To assess efficacy of the 3 treatments, serial blood samples were analyzed for hemoglobin (Hb), hematocrit (Hct), reticulocyte count, red blood cell indices and plasma levels of transferrin, transferrin receptor (TfR), ferritin, and iron. Oxidant injury was assessed before and after treatment by plasma and urine levels of malondialdehyde (MDA) and o-tyrosine.

RESULTS

At the end of treatment, Hb, Hct, reticulocyte count, and plasma TfR were markedly higher in both of the EPO-treated groups, compared with the oral iron group. At study exit a trend toward increasing Hb and Hct levels and significantly higher reticulocyte counts were observed in the intravenous iron + EPO group, compared with the EPO + oral iron group. During treatment, plasma ferritin levels increased significantly in the intravenous iron + EPO group and decreased significantly in the other 2 groups. By the end of treatment, ferritin levels were significantly higher in the intravenous iron + EPO group compared with the other 2 groups. Although plasma and urine MDA or o-tyrosine did not differ among the 3 groups, plasma MDA was significantly greater in the subgroup of intravenous iron + EPO participants sampled at the end of the 2-hour parenteral iron infusion, compared with values observed immediately before and after parenteral iron-dosing.

CONCLUSIONS

In stable VLBW infants receiving EPO treatment, parenteral supplementation with 2 mg/kg/day of iron sucrose results in a small, but significant, augmentation of erythropoiesis beyond that of r-HuEPO and enteral iron alone. However, to reduce the potential adverse effects of parenteral iron/kg/day on increasing plasma ferritin levels and on causing oxidative injury, we suggest that the parenteral iron dose used should be reduced and/or the time of infusion extended to maintain a serum iron concentration below the total iron-binding capacity.

Venous and arterial hematologic profiles of very low birth weight infants. European Multicenter rhEPO Study Group

OBJECTIVE

In very low birth weight (VLBW) infants, diagnostic and therapeutic decisions depend on hematologic values. As few data are available, we studied the course during the first 6 weeks of life.

DESIGN

Four prospective longitudinal cohort studies were retrospectively combined assessing hematologic profiles of 562 VLBW infants. For characterization of red blood cells and iron, infants receiving erythropoietin were excluded. For characterization of white blood cells and platelets, infants receiving antibiotics were excluded.

RESULTS

The third (3rd)/median/97th percentiles on day 3 were as follows: hemoglobin: 11.0/15.6/19.8 g/dL; hematocrit: 35/47/60%; red blood cells: 3.2/4.2/5.3 x 10(12)/L; reticulocytes:. 6/7.1/27.8%; platelets: 58/203/430 x 10(9)/L; white blood cells: 3. 6/9.5/38.3 x 10(9)/L; neutrophils:.7/4.7/25.3 x 10(9)/L; ferritin: 27/140/504 ng/mL; iron:.8/7.5/26.7 micromol/L; transferrin saturation: 2.6/22.7/79.8%. Transferrin saturation was <24% in 51%, ferritin concentration <100 ng/mL in 32%, and platelets <150 x 10(9)/L in 29% of this population. The steady decrease of red cell parameters was mitigated by transfusions. Neutrophils decreased steadily, and were <1.75 x 10(9)/L in 35% at 6 weeks.

CONCLUSIONS

Iron indices and platelet counts on day 3 and neutrophil counts at 2 to 6 weeks of age are lower than previously assumed in VLBW infants and lower than in larger prematures.

Prospective randomized trial of early versus late enteral iron supplementation in infants with a birth weight of less than 1301 grams

OBJECTIVES

To examine whether early enteral iron supplementation (EI) would improve serum ferritin as a measure of nutritional iron status at 2 months of age and would prevent definite iron deficiency (ID) in infants with a birth weight of <1301 g.

METHODS

Infants were randomly assigned to receive enteral iron supplementation of 2 to 6 mg/kg/day as soon as enteral feedings of >100 mL/kg/day were tolerated (EI) or at 61 days of life (late enteral iron supplementation [LI]). Nutritional iron status was assessed: 1) at birth, 2) at 61 days of life, 3) when the infants reached a weight of 1.6 times birth weight, and 4) before blood was transfused at a hematocrit of <.25. ID was defined by any one of the following criteria: ferritin, <12 microg/L; transferrin saturation, <17%; or increase of absolute reticulocyte counts by >50% one week after the onset of enteral iron supplementation. Restrictive red cell transfusion guidelines were followed and all transfusions were documented. Erythropoietin was not administered. The primary outcome variables were: 1) ferritin at 61 days and 2) the number of infants with ID.

RESULTS

Ferritin at 61 days was not different between the groups. Infants in the LI group were more often iron-deficient (26/65 vs 10/68) and received more blood transfusions after day 14 of life. No adverse effects of EI were noted.

CONCLUSIONS

EI is feasible and probably safe in infants with birth weight <1301 g. EI may reduce the incidence of ID and the number of late blood transfusions. ID may occur in very low birth weight infants despite early supplementation with iron and should be considered in the case of progressive anemia.preterm infant, iron supplementation, iron deficiency, blood transfusion.

Adaptive responses during anemia and its correction in lambs

There is limited information available on which to base decisions regarding red blood cell (RBC) transfusion treatment in anemic newborn infants. Using a conscious newborn lamb model of progressive anemia, we sought to identify accessible metabolic and cardiovascular measures of hypoxia that might provide guidance in the management of anemic infants. We hypothesized that severe phlebotomy-induced isovolemic anemia and its reversal after RBC transfusion result in a defined pattern of adaptive responses. Anemia was produced over 2 days by serial phlebotomy (with plasma replacement) to Hb levels of 30-40 g/l. During the ensuing 2 days, Hb was restored to pretransfusion baseline levels by repeated RBC transfusion. Area-under-the-curve methodology was utilized for defining the Hb level at which individual study variables demonstrated significant change. Significant reciprocal changes (P < 0.05) of equivalent magnitude were observed during the phlebotomy and transfusion phases for cardiac output, plasma erythropoietin (Epo) concentration, oxygen extraction ratio, oxygen delivery, venous oxygen saturation, and blood lactate concentration. No significant change was observed in resting oxygen consumption. Cardiac output and plasma Epo concentration increased at Hb levels <75 g/l, oxygen delivery and oxygen extraction ratio decreased at Hb levels <60 g/l, and venous oxygen saturation decreased and blood lactate concentration increased at Hb levels <55 g/l. We speculate that plasma Epo and blood lactate concentrations may be useful measures of clinically significant anemia in infants and may indicate when an infant might benefit from a RBC transfusion.

Temporal variation in serum nitrite levels in rats and mice

Although considerable evidence implicates involvement of nitric oxide (NO) in circadian regulation, little is known about possible 24 h variations in basal NO metabolism. In this study, daily variations in serum nitrite levels were studied in locally bred mice and rats during the months of September and October. The serum was separated from blood samples obtained at six different times of the day and night (1 h, 5 h, 9 h, 13 h, 17 h, and 21 h after lights off [HALO] from male albino mice and rats). As an index of in vivo NO generation, serum nitrite levels (determined by the diazotization method) in rats exhibited significant temporal fluctuation (unpaired Student t test), with the concentration highest at 5 HALO and 21 HALO and lowest at 9 HALO. No such temporal variation was detected in mice in these studies conducted on locally bred animals in the autumn.

Iron supplementation enhances response to high doses of recombinant human erythropoietin in preterm infants

AIMS

To determine whether iron supplementation would enhance erythropoiesis in preterm infants treated with high doses of human recombinant erythropoietin (r-HuEPO).

METHODS

Sixty three preterm infants were randomly allocated at birth to one of three groups to receive: r-HuEPO alone, 1200 IU/kg/week (EPO); or r-HuEPO and iron, 1200 IU/kg/week of r-HuEPO plus 20 mg/kg/week of intravenous iron (EPO + iron); or to serve as controls. All three groups received blood transfusions according to uniform guidelines.

RESULTS

Infants in the EPO + iron group needed fewer transfusions than controls--mean (95% CI) 1.0 (0.28-1.18) vs 2.9 (1.84-3.88) and received lower volumes of blood--mean (95% CI) 16.7 (4.9-28.6) vs 44.4 (29.0-59.7) ml/kg. The EPO group also needed lower volumes of blood than the controls--mean (95% CI) 20.1 (6.2-34.2) vs 44.4 (29.0-59.7) ml/kg, but the same number of transfusions, 1.3 (0.54-2.06) vs 2.9 (1.84-3.88). Reticulocyte and haematocrit values from postnatal weeks 5 to 8 were higher in the EPO + iron than in the EPO group, and both groups had higher values than the controls. Mean (SEM) plasma ferritin was lower in the EPO group-65 (55) micrograms/l than in the EPO + iron group 780 (182) micrograms/l, and 561 (228) micrograms/l in the control infants.

CONCLUSIONS

Early administration of high doses of r-HuEPO with iron supplements significantly reduced the need for blood transfusion. Intravenous iron (20 mg/kg/week in conjunction with r-HuEPO yielded a higher reticulocyte count and haematocrit concentration after the forth week of life than r-HuEPO alone. Infants treated with r-HuEPO alone showed signs of reduced iron stores.

High-versus low-dose erythropoietin in extremely low birth weight infants. The European Multicenter rhEPO Study Group

OBJECTIVE

To investigate whether a weekly 1500 IU/kg dose of recombinant human erythropoietin (rhEPO) is more effective than a dose of 750 IU/kg/week in preventing anemia and reducing the transfusion need in infants with birth weights less than 1000 gm.

STUDY DESIGN

In a randomized, double-blind, multicenter trial, 184 infants with birth weights between 500 and 999 gm were treated with either rhEPO 750 (low-dose group) or 1500 IU/kg/week (high-dose group) from day 3 of life until 37 weeks' corrected age.

RESULTS

Thirty-two percent of the infants in each group did not receive any transfusion during the treatment period. The total volume of erythrocytes received was similar in each group. The success rate, defined as no transfusion needed and hematocrit value 0.30 L/L or greater, was 27.6% in the low-dose and 29.5% in the high-dose group (p = 0.96).

CONCLUSION

Doubling the rhEPO dose of 750 IU/kg/week is not indicated in infants with birth weights less than 1000 gm.