Effects of transfusions in extremely low birth weight infants: a retrospective study

Characteristics of red blood cell transfusion among very preterm infants in China

BACKGROUND AND OBJECTIVES

National-level data on the incidence of red blood cell (RBC) transfusions and outcomes among very preterm infants (VPIs) are lacking in China. This study aims to describe the use and variation of RBC transfusion among VPIs in China.

MATERIALS AND METHODS

This cohort study was conducted among 70 tertiary hospitals participating in the Chinese Neonatal Network (CHNN) from 2019 to 2020 across China. All VPIs admitted to the CHNN neonatal intensive care units (NICUs) were included.

RESULTS

A total of 13,447 VPIs were enrolled, of whom 7026 (52.2%) received ≥1 RBC transfusions. The mean number of transfusions per infant was 2 (interquartile range [IQR] 1-4 times) and the median age at first transfusion was 15 days (IQR 3-27 days). The transfusion rate was higher in critically ill infants compared with non-critically ill infants (70.5% vs. 39.3%). The transfusion rate varied widely (13.5%-95.0%) between different NICUs. The prevalence of death, severe intra-ventricular haemorrhage, necrotizing enterocolitis (NEC) or spontaneous intestinal perforation (SIP), sepsis, bronchopulmonary dysplasia (BPD), severe retinopathy of prematurity (ROP) and cystic periventricular leukomalacia (cPVL) was significantly higher in the transfused group. Among non-critically ill infants, RBC transfusion was independently associated with BPD, severe ROP and cPVL.

CONCLUSION

Our study, providing the first baseline data on RBC transfusions among VPIs in China, shows an alarmingly high RBC transfusion rate with significant site variations. There is an urgent need for national guidelines on RBC transfusions for VPIs in China.

Banked term umbilical cord blood to meet the packed red blood cell transfusion needs of extremely-low-gestational-age neonates: a feasibility analysis

OBJECTIVES

To assess the feasibility of drawing, processing, safety-testing, and banking term umbilical cord blood to meet the packed red blood cell transfusion (RBC Tx) needs of extremely-low-gestational-age neonates (ELGANs).

DESIGN

(1) Retrospectively analyze all ELGANs RBC Tx over the past three years, (2) Estimate local cord blood availability, (3) Assess interest in this project, and implementation barriers, through stakeholder surveys.

RESULTS

In three years we cared for 266 ELGANs; 165 (62%) received ≥1 RBC Tx. Annual RBC Tx averaged 197 (95% CI, 152-243). If 10% of our 10,353 annual term births had cord blood drawn and processed, and half of those tested were acceptable for Tx, collections would exceed the 95th % upper estimate for need by >four-fold. Interest exceeded 97%. Identified barriers included FDA approval, training to collect cord blood, and cost.

CONCLUSION

RBC Tx needs of ELGANS could be met by local cord blood collection.

Packed Red Blood Cell Transfusion as a Predictor of Moderate-Severe Bronchopulmonary Dysplasia: A Comparative Cohort Study of Very Preterm Infants

OBJECTIVE

 Bronchopulmonary dysplasia (BPD) is a leading cause of morbidity and mortality in neonatal intensive care units. Our aim was to evaluate association between packed red blood cell transfusion and the development of BPD in very preterm infants.

STUDY DESIGN

 This retrospective study of very preterm infants (mean gestational age: 27.1 ± 2.4 weeks, birth weight: 970 ± 271 g) was conducted at Biruni University (Turkey) between July 2016 and December 2020.

RESULTS

 BPD developed in 107 of the 246 enrolled neonates, including 47 (43.9%), 27 (25.3%), and 33 (30.8%) diagnosed with mild, moderate, and severe BPD, respectively. A total of 728 transfusions were administered. The increased number (4 transfusions [2-7] vs. 1 [1-3], p = 0.001) and volume of transfusions (75 mL/kg volume [40-130] vs. 20 [15-43], p = 0.001) were significantly higher in infants with BPD compared to those without BPD. The transfusion volume cut-off for the prediction of BPD by receiver operating characteristic curve analysis was 42 mL/kg (sensitivity 73.6%; specificity 75%; area under the receiver-operating characteristic curve: 0.82). In multivariate analysis, multiple transfusions and larger transfusion volume were independent risk factors for moderate-severe BPD.

CONCLUSION

 The increased number and volume of transfusions were associated with BPD in very preterm infants. A packed red blood cell transfusion volume ≥42 mL/kg was a statistically significant predictor of the development of BPD at a postmenstrual age of 36 weeks.

KEY POINTS

· Transfusions were found to be an important risk factor for BPD development in very premature infants.. · Number and volume of transfusion were associated with the severity of BPD.. · Optimal cut point volume of transfusion for prediction of BPD was 42 mL/kg body weight..

Can Red Blood Cell and Platelet Transfusions Have a Pathogenic Role in Bronchopulmonary Dysplasia?

OBJECTIVE

To evaluate whether transfusions in infants born preterm contribute to the pathogenesis of bronchopulmonary dysplasia (BPD).

STUDY DESIGN

We conducted a multihospital, retrospective study seeking associations between red blood cell or platelet transfusions and BPD. We tabulated all transfusions administered from January 2018 through December 2022 to infants born ≤29 weeks or <1000 g until 36 weeks postmenstrual age and compared those with BPD grade. We performed a sensitivity analysis to assess the possibility of a causal relationship. We then determined whether each transfusion was compliant with restrictive guidelines, and we estimated effects fewer transfusions might have on future BPD incidence.

RESULTS

Eighty-four infants did not develop BPD and 595 did; 352 developed grade 1 (mild), 193 grade 2 (moderate), and 50 grade 3 (severe). Transfusions were given at <36 weeks to 7% of those who did not develop BPD, 46% who did, and 98% who developed severe BPD. For every transfusion the odds of developing BPD increased by a factor of 2.27 (95% CI, 1.59-3.68; P < .001). Sensitivity analyses suggested that transfusions might contribute to BPD. Fifty-seven percent of red blood cell transfusions and 68% of platelet transfusions were noncompliant with new restrictive guidelines. Modeling predicted that complying with restrictive guidelines could reduce the transfusion rate by 20%-30% and the moderate to severe BPD rate by ∼4%-6%.

CONCLUSIONS

Transfusions were associated with BPD incidence and severity. Lowering transfusion rates to comply with current restrictive guidelines might result in a small but meaningful reduction in BPD rates.

Trial-related blood sampling and red blood cell transfusions in preterm infants

AIM

To determine if trial-related blood sampling increases the risk of later red blood cell (RBC) transfusion in very preterm infants, we compared the volume of clinical- and trial-related blood samples, in a specific trial and correlated to subsequent RBC transfusion.

METHODS

For 193 very preterm infants, participating in the FortiColos trial (NCT03537365), trial-related blood volume drawn was in accordance with ethical considerations established by the European Commission. Medical records were reviewed to assess the number and accumulated volume (mL/kg) of blood samples (both clinical- and trial-related). Data were compared with the need of RBC transfusions during the first 28 days of life.

RESULTS

Mean (SD) gestational age and birth weight was 28 ± 1 weeks and 1168 ± 301 g. In total, 11% of total blood volume was drawn for sampling (8.1 ± 5.1 mL/kg) and trial-related sampling accounted for 1.6 ± 0.6 mL/kg. Trial-related blood sampling had no impact on RBC transfusion (p = 0.9).

CONCLUSION

Clinical blood sampling in very preterm infants is associated with blood loss and subsequent need for RBC transfusions. In a specific trial requiring blood samples, we found no additional burden of trial-related blood sampling. The study suggests that trial-related sampling is safe if European criteria are followed.

Near-Infrared Spectroscopy to Guide and Understand Effects of Red Blood Cell Transfusion

This review is a summary of available evidence regarding the use of near-infrared spectroscopy (NIRS) to help better guide and understand the effects of red blood cell (RBC) transfusion in neonatal patients. We review recent literature demonstrating the changes that take place in regional tissue oxygen saturation (rSO2) resulting from RBC transfusion. We also discuss in detail if any correlation exists between rSO2 and hemoglobin values in neonates. Finally, we review studies that have evaluated the use of NIRS as a transfusion guide during neonatal intensive care.

Comparison of restrictive and liberal red blood cell suspension transfusion and analysis of influencing factors on prognosis of premature infants

OBJECTIVE

To investigate the influence of restrictive and liberal red blood cell suspension (RBCs) transfusions on the prognosis of premature infants and to analyze the influencing factors to provide a reference for the transfusion strategy of preterm infants.

METHODS

Retrospective analysis was conducted on 85 cases of anemic premature infants treated in our center, including 63 cases in the restrictive transfusion group and 22 in the liberal transfusion group.

RESULTS

RBCs transfusions were effective in both groups, and there were no statistically significant differences in post-transfusion hemoglobin and hematocrit between the two groups (P > 0.05). The outcome events: the duration of ventilatory support was statistically prolonger in the restrictive group compared with the liberal group (P < 0.001); however, the differences in mortality, the increased weight before discharge, and length of stay in the hospital within the two groups were not statistically significant (P = 0.237, 0.36 and 0.771, respectively). Univariate survival analysis showed that age, birth weight, Apgar 1 min and Apgar 10 min scores were the influencing factors for death, with P values of 0.035, 0.004, <0.001, and 0.013, respectively; COX regression analysis showed that Apgar 1 min score was an independent factor of the survival time of preterm infants (P = 0.002).

CONCLUSION

Compared with the restrictive transfusion group, liberal transfusion patients presented a shorter duration of ventilatory support, which is more beneficial to the prognosis of premature infants.

Study protocol of the WashT Trial: transfusion with washed versus unwashed red blood cells to reduce morbidity and mortality in infants born less than 28 weeks' gestation - a multicentre, blinded, parallel group, randomised controlled trial

INTRODUCTION

Many extremely preterm newborns develop anaemia requiring a transfusion, with most receiving three to five transfusions during their admission. While transfusions save lives, the potential for transfusion-related adverse outcomes is an area of growing concern. Transfusion is an independent predictor of death and is associated with increased morbidity, length of hospital stay, risk of infection and immune modulation. The underlying mechanisms include adverse pro-inflammatory and immunosuppressive responses. Evidence supports an association between transfusion of washed red cells and fewer post-transfusion complications potentially through removal of chemokines, lipids, microaggregates and other biological response modifiers. However, the clinical and cost-effectiveness of washed cells have not been determined.

METHODS AND ANALYSIS

This is a multicentre, randomised, double-blinded trial of washed versus unwashed red cells. Infants <28 weeks' gestation requiring a transfusion will be enrolled. Transfusion approaches will be standardised within each study centre and will occur as soon as possible with a recommended fixed transfusion volume of 15 mL/kg whenever the haemoglobin is equal to or falls below a predefined restrictive threshold, or when clinically indicated. The primary outcome is a composite of mortality and/or major morbidity to first discharge home, defined as one or more of the following: physiologically defined bronchopulmonary dysplasia; unilateral or bilateral retinopathy of prematurity grade >2, and; necrotising enterocolitis stage ≥2. To detect a 10% absolute reduction in the composite outcome from 69% with unwashed red blood cell (RBCs) to 59% with washed RBCs with 90% power, requires a sample size of 1124 infants (562 per group). Analyses will be performed on an intention-to-treat basis with a prespecified statistical analysis plan. A cost-effectiveness analysis will also be undertaken.

ETHICS AND DISSEMINATION

Ethics approval has been obtained from the Women's and Children's Health Network Human Research Ethics Committee (HREC/12/WCHN/55). The study findings will be disseminated through peer-reviewed articles and conferences.

TRIAL REGISTRATION NUMBER

ACTRN12613000237785 Australian New Zealand Clinical Trials Registry.

Impacts of cigarette smoking on blood circulation: do we need a new approach to blood donor selection?

Smoking is a major public health problem and is considered the leading cause of preventable death worldwide. Gas-phase smoke carries bioactive substances and toxic compounds, affecting human health and reducing life spans. The negative effects of smoking on red blood cell (RBC) quality include destroying RBCs and increasing carboxy hemoglobin (COHb). Smoking increases the concentrations of heavy metals such as cadmium (Cd) and lead (Pb) in the blood. Moreover, tobacco smoking has been found to be associated with heightened platelet (PLT)-dependent thrombin level which will induce a prothrombotic state. Smoking may affect the blood circulation of donors, and subsequently the blood components, and ultimately the recipients of transfusion. Nevertheless, there are no restrictions on smoking for volunteer blood donor screenings currently. We reviewed the articles about the influence of smoking on smokers' blood circulation as well as the impact of donated blood products on transfusion when these smokers act as blood donors. We aim to attract blood collection centers' attention to strengthen the management of blood donors who smoke, avoiding their use in massive transfusion protocol and susceptible recipients, especially pediatric ones.

Association between red blood cell transfusion and bronchopulmonary dysplasia: a systematic review and meta-analysis

Background

We aimed to determine the association between red blood cell transfusions (RBCT) and bronchopulmonary dysplasia (BPD) in neonates.

Methods

A systematic review and meta-analysis were conducted using data obtained from literature search of PubMed, Embase, and Web of Science from their inception till May 1, 2022. Two reviewers independently selected potentially relevant studies, and after data extraction, they assessed the methodological quality of the included studies using the Newcastle-Ottawa scale. Data were pooled using random-effects models in Review Manager 5.3. Subgroup-analysis was performed based on the number of transfusions and adjusted results.

Results

Of the 1,011 identified records, 21 total case-control, cross-sectional, and cohort studies were selected, which included a total of 6,567 healthy controls and 1,476 patients with BPD. The pooled unadjusted odds ratio ([OR], 4.01; 95% confidence interval [CI] 2.31-6.97) and adjusted OR (5.11; 95% CI 3.11-8.4) showed significant association between RBCT and BPD. A substantial heterogeneity was noted, which could be due to different variables controlled for in each study. The subgroup analysis showed that heterogeneity may be partially explained by the extent of transfusion.

Conclusion

The association between BPD and RBCT remains unclear based on the current data due to the substantial heterogeneity among the results. Well-designed studies are still needed in the future.

Modifiable Risk Factors and Preventative Strategies for Severe Retinopathy of Prematurity

Severe ROP is characterized by the development of retinal fibrovascular proliferation that may progress to retinal detachment. The purpose of this report is to review five of the most common and well-studied perinatal and neonatal modifiable risk factors for the development of severe ROP. Hyperoxemia, hypoxia, and associated prolonged respiratory support are linked to the development of severe ROP. While there is a well-established association between clinical maternal chorioamnionitis and severe ROP, there is greater variability between histologic chorioamnionitis and severe ROP. Neonatal sepsis, including both bacterial and fungal subtypes, are independent predictors of severe ROP in preterm infants. Although there is limited evidence related to platelet transfusions, the risk of severe ROP increases with the number and volume of red blood cell transfusions. Poor postnatal weight gain within the first six weeks of life is also strongly tied to the development of severe ROP. We also discuss preventative strategies that may reduce the risk of severe ROP. Limited evidence-based studies exist regarding the protective effects of caffeine, human milk, and vitamins A and E.

Iron supplementation and the risk of bronchopulmonary dysplasia in extremely low gestational age newborns

BACKGROUND

The aim of this study was to determine the relationship between iron exposure and the development of bronchopulmonary dysplasia (BPD).

METHODS

A secondary analysis of the PENUT Trial dataset was conducted. The primary outcome was BPD at 36 weeks gestational age and primary exposures of interest were cumulative iron exposures in the first 28 days and through 36 weeks' gestation. Descriptive statistics were calculated for study cohort characteristics with analysis adjusted for the factors used to stratify randomization.

RESULTS

Of the 941 patients, 821 (87.2%) survived to BPD evaluation at 36 weeks, with 332 (40.4%) diagnosed with BPD. The median cohort gestational age was 26 weeks and birth weight 810 g. In the first 28 days, 76% of infants received enteral iron and 55% parenteral iron. The median supplemental cumulative enteral and parenteral iron intakes at 28 days were 58.5 and 3.1 mg/kg, respectively, and through 36 weeks' 235.8 and 3.56 mg/kg, respectively. We found lower volume of red blood cell transfusions in the first 28 days after birth and higher enteral iron exposure in the first 28 days after birth to be associated with lower rates of BPD.

CONCLUSIONS

We find no support for an increased risk of BPD with iron supplementation.

TRIAL REGISTRATION NUMBER

NCT01378273. https://clinicaltrials.gov/ct2/show/NCT01378273 IMPACT: Prior studies and biologic plausibility raise the possibility that iron administration could contribute to the pathophysiology of oxidant-induced lung injury and thus bronchopulmonary dysplasia in preterm infants. For 24-27-week premature infants, this study finds no association between total cumulative enteral iron supplementation at either 28-day or 36-week postmenstrual age and the risk for developing bronchopulmonary dysplasia.

Development of necrotizing enterocolitis after blood transfusion in very premature neonates

BACKGROUND

Prior studies report conflicting evidence on the association between packed red blood cell (PRBC) transfusions and necrotizing enterocolitis (NEC), especially in early weeks of life where transfusions are frequent and spontaneous intestinal perforation can mimic NEC. The primary objective of this study was to evaluate the association between PRBC transfusions and NEC after day of life (DOL) 14 in very premature neonates.

METHODS

A retrospective cohort analysis of very premature neonates was conducted to investigate association between PRBC transfusions and NEC after DOL 14. Primary endpoints were PRBC transfusions after DOL 14 until the date of NEC diagnosis, discharge, or death. Wilcoxon ranked-sum and Fisher's exact tests, Cox proportional hazards regression, and Kaplan-Meier curves were used to analyze data.

RESULTS

Of 549 premature neonates, 186 (34%) received transfusions after DOL 14 and nine (2%) developed NEC (median DOL = 38; interquartile range = 32-46). Of the nine with NEC after DOL 14, all were previously transfused (P < 0.001); therefore, hazard of NEC could not be estimated. Post hoc analysis of patients from DOL 10 onward included five additional patients who developed NEC between DOL 10 and DOL 14, and the hazard of NEC increased by a factor of nearly six after PRBC transfusion (hazard ratio = 5.76, 95% confidence interval = 1.02-32.7; P = 0.048).

CONCLUSIONS

Transfusions were strongly associated with NEC after DOL 14. Prospective studies are needed to determine if restrictive transfusion practices can decrease incidence of NEC after DOL 14.

Effectiveness of zinc protoporphyrin/heme ratio and ferritin for assessing iron status in preterm infants

BACKGROUND

Since iron is crucial for many tissue processes, we, therefore, aimed to assess ferritin and the zinc protoporphyrin to heme ratio (ZnPP/H) as indicators of iron status in preterm newborns, particularly during certain inflammatory episodes.

METHODS

From 170 preterm babies, paired ferritin and ZnPP/H measurements were collected twice (on the first postnatal day and six weeks later). To compare these measures and assess the impact of anemia, sepsis, and packed red blood cell transfusion (PRBT), three different scenarios were considered.

RESULTS

Compared to the non-anemic group, the anemic patients' serum ferritin level was considerably lower (p = 0.044), whereas the anemic patients' ZPP/H ratio was significantly greater (p < 0.001). In neonates with sepsis, ferritin levels were considerably greater in both anemic and non-anemic septic neonates compared to neonates without sepsis (p < 0.001 for each). Regarding ZPP/H ratio, no appreciable variations were found between the two groups. In addition, serum ferritin significantly increased following each PRBT (p < 0.001 for each). As a result of each PRBT, the ZPP/H ratio considerably decreased (p < 0.001).

CONCLUSION

As a measure of iron status during particular inflammatory processes like infection and PRBT, ZnPP/H may be more accurate.

BORN study: a multicenter randomized trial investigating cord blood red blood cell transfusions to reduce the severity of retinopathy of prematurity in extremely low gestational age neonates

BACKGROUND

Extremely low gestational age neonates (ELGANs, i.e., neonates born before 28 weeks of gestation) are at high risk of developing retinopathy of prematurity (ROP), with potential long-life visual impairment. Due to concomitant anemia, ELGANs need repeated red blood cell (RBC) transfusions. These produce a progressive replacement of fetal hemoglobin (HbF) by adult hemoglobin (HbA). Furthermore, a close association exists between low levels of HbF and severe ROP, suggesting that a perturbation of the HbF-mediated oxygen release may derange retinal angiogenesis and promote ROP.

METHODS/DESIGN

BORN (umBilical blOod to tRansfuse preterm Neonates) is a multicenter double-blinded randomized controlled trial in ELGANs, to assess the effect of allogeneic cord blood RBC transfusions (CB-RBCs) on severe ROP development. Recruitment, consent, and randomization take place at 10 neonatology intensive care units (NICUs) of 8 Italian tertiary hospitals. ELGANs with gestational age at birth comprised between 24+0 and 27+6 weeks are randomly allocated into two groups: (1) standard RBC transfusions (adult-RBCs) (control arm) and (2) CB-RBCs (intervention arm). In case of transfusion need, enrolled patients receive transfusions according to the allocation arm, unless an ABO/RhD CB-RBC is unavailable. Nine Italian public CB banks cooperate to make available a suitable amount of CB-RBC units for all participating NICUs. The primary outcome is the incidence of severe ROP (stage 3 or higher) at discharge or 40 weeks of postmenstrual age, which occurs first.

DISCUSSION

BORN is a groundbreaking trial, pioneering a new transfusion approach dedicated to ELGANs at high risk for severe ROP. In previous non-randomized trials, this transfusion approach was proven feasible and able to prevent the HbF decrease in patients requiring multiple transfusions. Should the BORN trial confirm the efficacy of CB-RBCs in reducing ROP severity, this transfusion strategy would become the preferential blood product to be used in severely preterm neonates.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05100212. Registered on October 29, 2021.

Association of red blood cell transfusion volume with postoperative complications and mortality in neonatal surgery

INTRODUCTION

Red blood cell transfusion (RBCT) is commonly administered in neonatal surgical care in the absence of clear clinical indications such as active bleeding or anemia. We hypothesized that higher RBCT volumes are associated with worse postoperative outcomes.

METHODS

Neonates within the National Surgical Quality Improvement Program-Pediatric database who underwent inpatient surgery (2012-2016) were stratified by weight-based RBCT volume: <20cc/kg, 20-40cc/kg, and >40cc/kg. Postoperative complications were categorized as wound, systemic infection, central nervous system (CNS), renal, pulmonary, and cardiovascular. Multivariable logistic regression and cubic spline analysis were used to evaluate the association between RBCT volume, postoperative complications, and 30-day mortality. Sensitivity analysis was conducted by performing propensity score matching.

RESULTS

Among 9,877 neonates, 1,024 (10%) received RBCTs. Of those who received RBCT, 53% received <20cc/kg, 27% received 20-40cc/kg, and 20% received >40cc/kg. Relative to neonates who were not transfused, RBCT volume was associated with a dose-dependent increase in renal complications, CNS complications, cardiovascular complications, and 30-day mortality. With cubic spline analysis, a lone inflection point for 30-day mortality was identified at a RBCT volume of 30 - 35 cc/kg. After propensity score matching, the dose-dependent relationship was still present for 30-day mortality.

CONCLUSION

Total RBCT volume is associated with worse postoperative outcomes in neonates with a significant increase in 30-day mortality at a RBCT volume of 30 - 35 cc/kg. Future prospective studies are needed to better understand the association between large RBCT volumes and poor outcomes after neonatal surgery.

LEVEL OF EVIDENCE

Level IV, Retrospective cohort study.

Blood products transfusion and retinopathy of prematurity: A cohort study

AIM

The aim of the study was to assess the influence of blood product transfusions on the development and severity of retinopathy of prematurity (ROP).

METHODS

A retrospective cohort study was conducted of very low birth weight (VLBW) newborns with less than 32 weeks gestational age (GA) admitted to the neonatal unit of a tertiary care hospital during the period from 1 January 2008 to 31 December 2021. Data on the degree of ROP and the transfusions received were obtained and analysed. Both univariate and multivariate analyses were performed, by logistic regression.

RESULTS

A total of 565 VLBW newborns were recruited, of whom 263 received a red blood cell transfusion prior to 36 weeks corrected GA. The newborns with ROP received significantly more red blood cell transfusions than those not presenting this condition. After adjusting for oxygen therapy and GA, the risk of ROP was found to be 2.77 times higher (95% CI 1.31-5.88) after receiving three or more transfusions, with a 3.95 times higher risk (95% CI 1.40-11.1) of developing severe ROP. Having received the first red blood cell transfusion before 32 weeks corrected GA is associated with an increased risk of ROP (OR 2.18; 95% CI: 1.09-4.36).

CONCLUSION

In VLBW neonates, the number of red blood cell transfusions and their administration before 32 weeks corrected GA are important risk factors for ROP.

Every treasured drop! Blood transfusion requirements in very preterm neonates after implementation of blood conservation strategies: an observational analytical study

BACKGROUND

Certain morbidities are inevitable in preterm infants; the challenge lies in minimizing them. Anemia of prematurity is multifactorial. Therapy largely depends on adult red blood cell transfusions (RBCT); which inherently, are not without problems. Most literature in this respect are retrospective or evaluate individual stratagems to reduce RBCT.

METHODS

This observational analytical study was planned to compare need for RBCT, before and after institution of blood conservation strategies (BCS). All those ≤30 weeks gestation at birth during two-time epochs were included (Before BCS: retrospective; After BCS: prospective). BCS constituted of delayed cord clamping (DCC), strict sampling indications, micro-sampling with point-of-care testing (MS-POCT) and adherence to RBCT thresholds.

RESULTS

Of 45 enrolled neonates in each group, proportion of those requiring even 1 RBCT was significantly reduced after BCS [51.1% vs. 26.7%, p = 0.02, OR 0.35, 95%CI (0.14, 0.84)]. Calculated cumulative blood volume losses (35.3 ml vs. 21.9 ml) and loss per kilogram birth weight (35.3 ml/kg vs. 20.12 ml/kg) were significantly lower after BCS (p = 0.0036). Need for &gt;1 RBCT, mean lowest Hb, mean maximum-hemoglobin drop, need for arterial lines were reduced. Adherence to RBCT thresholds were acceptably good in both time epochs. However, the compliance to DCC was low in both groups, identifying one area of focus with scope for massive improvement.

CONCLUSIONS

Need for RBCT transfusions largely attributable to reduced blood losses for lab analysis were reduced after BCS. Installation of in-house MS-POCT seemed to be the pivotal factor. Units that care for very preterm infants must make attempts to procure MS-POCT equipment.

Packed red blood cell transfusion in preterm infants

Premature infants commonly receive adult packed red blood cells (pRBCs) during their hospital stay. As adult erythrocytes differ substantially from those of preterm infants, transfusion of adult pRBCs into preterm infants can be considered inappropriate for the physiology of a preterm infant. An absence of standardisation of transfusion protocols makes it difficult to compare and interpret pertinent clinical data, as reflected by unclear associations between pRBC transfusion and complications related to prematurity, such as bronchopulmonary dysplasia, neurodevelopmental impairment, retinopathy of prematurity, or necrotising enterocolitis. The difficulty in interpreting clinical data is further increased by differences in study designs that either overestimate pRBC-associated complications of prematurity or have not yet been designed to directly link pRBC transfusions to their respective complications. Thus, neonatal transfusion practice has become an ongoing difficulty, in which differences in transfusion guidelines hinder the ability to generate comparable clinical data, and heterogeneity in clinical data prevents the implementation of standardised transfusion protocols. To overcome these issues, novel approaches with biochemical-clinical translational designs could enable clinicians to gather causal evidence instead of circumstantial correlation.

Neurosensory Alterations in Retinopathy of Prematurity: A Window to Neurological Impairments Associated to Preterm Birth

Retinopathy of prematurity (ROP) is one of the main blinding diseases affecting preterm newborns and is classically considered a vascular disorder. The premature exposure to the extrauterine environment, which is hyperoxic in respect to the intrauterine environment, triggers a cascade of events leading to retinal ischemia which, in turn, makes the retina hypoxic thus setting off angiogenic processes. However, many children with a history of ROP show persistent vision impairment, and there is evidence of an association between ROP and neurosensory disabilities. This is not surprising given the strict relationship between neuronal function and an adequate blood supply. In the present work, we revised literature data evidencing to what extent ROP can be considered a neurodegenerative disease, also taking advantage from data obtained in preclinical models of ROP. The involvement of different retinal cell populations in triggering the neuronal damage in ROP was described along with the neurological outcomes associated to ROP. The situation of ROP in Italy was assessed as well.

Predictors of Bronchopulmonary Dysplasia in 625 Neonates with Respiratory Distress Syndrome

OBJECTIVE

This study was designed to investigate the predictors of bronchopulmonary dysplasia in neonates with respiratory distress syndrome.

METHODS

This was a single-center retrospective cohort study conducted between 1 January 2015 and 31 December 2020. A total of 625 neonates with respiratory distress syndrome (RDS) were enrolled. Demographic data, clinical presentations, complications and related treatment information were collected and analyzed. We used bivariate and multivariate logistic-regression analyses to determine significant predictors of bronchopulmonary dysplasia (BPD) in RDS neonates.

RESULTS

In these 625 neonates, 102 (16.3%) of them developed BPD. Bivariate analysis and multivariate logistic-regression analyses revealed that birthweight, gestational age under 32 weeks, duration of oxygen therapy over 10 days, asphyxia, patent ductus arteriosus, transfusion of red blood cells (packed red blood cells) and surfactant use were significantly associated with the development of BPD.

CONCLUSION

Birthweight, gestational age <32 weeks, total duration of oxygen therapy >10 days, asphyxia, patent ductus arteriosus, need for red blood cell infusion, and the use of pulmonary surfactant were important predictors of BPD in neonates with RDS.

Erythropoietin for preventing bronchopulmonary dysplasia in preterm infants: A systematic review and meta-analysis

BACKGROUND

Recombinant erythropoietin (rEPO) has erythropoiesis and anti-inflammatory properties that might help reduce lung injury in preterm infants.

OBJECTIVE

To conduct a systematic review and meta-analysis to evaluate the possible role of rEPO in altering the risk of bronchopulmonary dysplasia (BPD).

METHODS

PubMed, EMBASE, Web of Science, and the Cochrane Library databases were searched to identify randomized controlled trials (RCTs) that evaluated the effects of rEPO for the prevention of BPD in preterm infants.

RESULTS

Fourteen studies (3199 infants) were included. Our results could not demonstrate a significant effect of rEPO on the incidence of BPD36 (risk ratio [RR]: 0.97, 95% confidence interval [CI]: 0.87-1.09, p = 0.63, I²  = 0, 12 RCTs, high-quality evidence), BPD28 (RR: 1.28, 95% CI: 0.91-1.79, p = 0.15, I²  = 17%, three RCTs, low-quality evidence) and oxygen dependence days. The test for subgroup analysis by administration route of rEPO showed similar outcomes above. Some of the included trials reported a significant effect of intravenous rEPO on reduction of sepsis (RR: 0.82, 95% CI: 0.70-0.96, p = 0.01, I²  = 0, high-quality evidence) and any stage necrotizing enterocolitis (NEC) (RR: 0.75, 95% CI: 0.59-0.94, p = 0.01, I²  = 0, moderate-quality evidence). The incidence of mortality and stage II or higher NEC was comparable in rEPO and control infants.

CONCLUSION

Our results suggest that rEPO does not affect the risk of developing BPD in preterm infants. Adequately powered RCTs are required to further confirm these findings.

Effect of washed versus unwashed red blood cells on transfusion-related immune responses in preterm newborns

Objectives

Transfusion with washed packed red blood cells (PRBCs) may be associated with reduced transfusion‐related pro‐inflammatory cytokine production. This may be because of alterations in recipient immune responses.

Methods

This randomised trial evaluated the effect of transfusion with washed compared with unwashed PRBCs on pro‐inflammatory cytokines and endothelial activation in 154 preterm newborns born before 29 weeks’ gestation. Changes in plasma cytokines and measures of endothelial activation in recipient blood were analysed after each of the first three transfusions.

Results

By the third transfusion, infants receiving unwashed blood had an increase in IL‐17A (P = 0.04) and TNF (P = 0.007), whereas infants receiving washed blood had reductions in IL‐17A (P = 0.013), TNF (P = 0.048), IL‐6 (P = 0.001), IL‐8 (P = 0.037), IL‐12 (P = 0.001) and IFN‐γ (P = 0.001). The magnitude of the post‐transfusion increase in cytokines did not change between the first and third transfusions in the unwashed group but decreased in the washed group for IL‐12 (P = 0.001), IL‐17A (P = 0.01) and TNF (P = 0.03), with the difference between the groups reaching significance by the third transfusion (P < 0.001 for each cytokine).

Conclusion

The pro‐inflammatory immune response to transfusion in preterm infants can be modified when PRBCs are washed prior to transfusion. Further studies are required to determine whether the use of washed PRBCs for neonatal transfusion translates into reduced morbidity and mortality.

The short-term effects of RBC transfusions on intestinal injury in preterm infants

BACKGROUND

Anemic preterm infants may require red blood cell (RBC) transfusions to maintain sufficient oxygen supply to vital organs. Transfusion treatment, however, may have adverse intestinal effects. We aimed to investigate the short-term effects of RBC transfusions, hypothesizing to find signs of oxidative stress and intestinal injury, possibly related to levels of splanchnic (re-)oxygenation.

METHODS

We prospectively included preterm infants (gestational age < 32 weeks). We measured urinary biomarkers for oxidative stress (8-isoprostane) and intestinal cell injury (intestinal fatty acid-binding protein, I-FABP) shortly before and after RBC transfusion. Splanchnic oxygen saturation (r_sSO₂) and r_sSO₂ variability were assessed simultaneously.

RESULTS

Twenty-nine preterm infants received 58 RBC transfusions at various postnatal ages. Six of them developed necrotizing enterocolitis (NEC) after transfusion. Urinary 8-isoprostane and I-FABP increased following RBC transfusion (median 282-606 pg/ml and 4732-6968 pg/ml, p < 0.01), more pronounced in infants who developed NEC. Change in I-FABP correlated with change in 8-isoprostane (rho = 0.623, p < 0.01). Lower r_sSO₂ variability, but not higher mean r_sSO₂ was associated with higher 8-isoprostane and I-FABP levels after transfusion.

CONCLUSIONS

Preterm RBC transfusions are associated with concomitant signs of oxidative stress and intestinal injury, parallel with lower variability in splanchnic oxygenation. This may represent the early pathogenetic process of transfusion-associated NEC.

IMPACT

Red blood cell (RBC) transfusions in preterm infants are associated with a near 2-fold increase in urinary biomarkers for oxidative stress (8-isoprostane) and intestinal cell injury (intestinal fatty acid-binding protein, I-FABP). Magnitude of change in I-FABP strongly correlated with the magnitude of 8-isoprostane change, suggesting a role for oxidative stress in the pathogenesis of intestinal injury. Lower splanchnic oxygen saturation variability following RBC transfusion was associated with higher 8-isoprostane and I-FABP levels. Loss of splanchnic variability after RBC transfusion may result from increased oxidative stress and its concomitant intestinal injury, possibly representing the early pathogenetic process of transfusion-associated necrotizing enterocolitis.

Treating Apnea of Prematurity

Premature babies often suffer apnea of prematurity as a physiological consequence of an immature respiratory system. Hypercapnia may develop, and neonates with apnea of prematurity are at an increased risk of morbidity and mortality. The long-term effects of apnea of prematurity or their treatments are less clear. While a number of treatment options exist for apnea of prematurity, there is no clear-cut “first-line” approach or gold standard of care. Effective treatments, such as caffeine citrate, carbon dioxide inhalation, nasal continuous positive airway pressure, nasal intermittent positive pressure ventilation, and others, may be associated with safety concerns. More conservative treatments are available, such as kangaroo care, postural changes, and sensory stimulation, but they may not be effective. While apnea of prematurity resolves spontaneously as the respiratory system matures, it can complicate neonatal care and may have both short-term and long-term consequences. The role, if any, that apnea of prematurity may play in mortality of preterm neonates is not clear.

Transfusion-Free Survival Predicts Severe Retinopathy in Preterm Neonates

Repeated red blood cell (RBC) transfusions are thought to increase the risk for retinopathy of prematurity (ROP), likely due to a critical fetal hemoglobin (HbF) reduction. In this study, we investigated if the postmenstrual age (PMA) of neonates at transfusion influences the risk for ROP. We estimated the cumulative transfusion-free survival (TFS) in a series of 100 preterm neonates receiving one or more RBC units. TFS was calculated by censoring patients at first transfusion and expressing the time between birth and transfusion as either PMA or postnatal day. Then, we investigated if TFS predicted the occurrence of severe ROP, defined as ROP stage 3 or higher. We found that neonates with severe ROP displayed a significantly shorter TFS expressed according to their PMA (p = 0.001), with similar TFS according to postnatal days. At receiver operating characteristic (ROC) curve analysis, receiving an RBC unit before week 28 of PMA predicted severe ROP with a sensitivity of 64% and a specificity of 78%. In addition, receiving a second RBC unit before the PMA of 29 weeks predicted severe ROP with a sensitivity of 75% and a specificity of 69%. At multivariate analysis, PMA at the second transfusion was even more informative than at first transfusion and outperformed all other variables in predicting severe ROP, with an odds ratio of 4.554 (95% CI 1.332-15.573, p = 0.016). Since HbF decrease is greater after multiple RBC transfusions, it is conceivable that neonates receiving more than one unit before the PMA of 29 weeks may be exposed to a greater disturbance of retinal vascularization. Any strategy aimed at preventing the critical HbF decrease at this low age might potentially reduce the risk for severe ROP.

The limited management options for apnoea of prematurity

WHAT IS KNOWN AND OBJECTIVE

About 10% of all infants are born prematurely. Almost all of those of gestational age less than about 30 weeks, and about half of those of gestational age up to about 35 weeks, are subject to unpredictable interruptions of breathing-known as "apnoea of prematurity" (AOP). We present a synopsis of the problem and point out the limited management options.

COMMENT

A basal rate for spontaneous breathing is normally maintained by integrated action of generator cells in the brainstem and feedback from central and peripheral chemosensors. In AOP, there are intermittent periods (seconds) lacking spontaneous firing, which results in hypoxia and hypercapnia. The long-term consequences of these interruptions in oxygen supply to tissues are not known. Although many treatment modalities are used, including drug therapy, nonpharmacologic care and mechanical intervention, there is no universally effective first-line management for AOP. Caffeine citrate is generally the most frequently used pharmacotherapeutic agent, but its side effect profile narrows with higher doses and the upper limit is still being investigated to discern the greatest benefit-to-risk ratio; thus, most infants do not achieve complete resolution of apnoeas.

WHAT IS NEW AND CONCLUSION

Given the widespread and serious nature of the problem of AOP, there is a surprising lack of treatment options. A more consistent and effective treatment, alone or as adjunct, would be welcome.

Effect of blood transfusions on cognitive development in very low birth weight infants

OBJECTIVE

Preterm infants frequently receive red cell transfusions; however, the effect of transfusions on cognition is unclear. We evaluated the relationship between transfusions and cognitive outcomes in preterm infants enrolled in a randomized trial of erythropoiesis stimulating agents (ESAs).

STUDY DESIGN

Preterm infants were randomized to ESAs or placebo during initial hospitalization, and transfusions recorded. Children were evaluated using standard developmental tests of cognition at 18-22 months (56 ESA, 24 placebo) and 3.5-4 years (39 ESA, 14 placebo).

RESULTS

Cognitive scores at 18-22 months were inversely correlated with transfusion volume (p = 0.02). Among those receiving ≥1 transfusion, cognitive scores were significantly higher in the ESA-treated group (p = 0.003). At 3.5-4 years, transfusions were not correlated with cognitive scores.

CONCLUSIONS

In the placebo group, transfused children had lower cognitive scores than did non-transfused children at 18-22 months. In the ESA group, cognitive scores did not differ by transfusion status, suggesting ESAs might provide neuroprotection.

Transfusion-associated necrotizing enterocolitis (NEC) in extremely preterm infants: experience of a tertiary neonatal center in UK

OBJECTIVE

To compare the characteristics and short-term outcomes in extremely preterm infants, who developed necrotizing enterocolitis (NEC) following a packed red blood cell transfusion (pRBC) within 48 h (TANEC), with those who developed NEC beyond 48 h (non-TANEC).

SETTING

A single-center retrospective cohort study in a Tertiary neonatal intensive care unit in the UK over a 5-year period.

PATIENTS AND METHODS

Extremely premature infants (23-27 weeks gestation) were selected. TANEC and non-TANEC incidence were calculated from the confirmed NEC group (defined as modified Bell's stage II and beyond). The characteristics and short-term outcomes of infants with TANEC in the first 8 weeks of life were compared to infants with non-TANEC.

RESULTS AND INTERPRETATION

Incidence of confirmed NEC was 14% (28/207). On further subgroup analysis of the confirmed NEC cases, 46% (13/28) of infants were identified with TANEC and 54% (15/28) with non-TANEC. The incidence of TANEC did not correlate with the number of antecedent pRBC transfusions or the pre-transfusion median hemoglobin (Hb) levels. There were no significant differences in characteristics between the TANEC and non-TANEC groups. Infants within the TANEC group required more intensive neonatal care support, greater surgical intervention (p-value 0.043) with loss of gut integrity and an increase in number of TPN dependency days (p-value 0.014).

CONCLUSIONS

A significantly worse clinical course and short-term outcome was observed in the TANEC group when compared with the non-TANEC group.

Anemia and Red Blood Cell Transfusions, Cerebral Oxygenation, Brain Injury and Development, and Neurodevelopmental Outcome in Preterm Infants: A Systematic Review

Background: Anemia remains a common comorbidity of preterm infants in the neonatal intensive care unit (NICU). Left untreated, severe anemia may adversely affect organ function due to inadequate oxygen supply to meet oxygen requirements, resulting in hypoxic tissue injury, including cerebral tissue. To prevent hypoxic tissue injury, anemia is generally treated with packed red blood cell (RBC) transfusions. Previously published data raise concerns about the impact of anemia on cerebral oxygen delivery and, therefore, on neurodevelopmental outcome (NDO). Objective: To provide a systematic overview of the impact of anemia and RBC transfusions during NICU admission on cerebral oxygenation, measured using near-infrared spectroscopy (NIRS), brain injury and development, and NDO in preterm infants. Data Sources: PubMed, Embase, reference lists. Study Selection: We conducted 3 different searches for English literature between 2000 and 2020; 1 for anemia, RBC transfusions, and cerebral oxygenation, 1 for anemia, RBC transfusions, and brain injury and development, and 1 for anemia, RBC transfusions, and NDO. Data Extraction: Two authors independently screened sources and extracted data. Quality of case-control studies or cohort studies, and RCTs was assessed using either the Newcastle-Ottawa Quality Assessment Scale or the Van Tulder Scale, respectively. Results: Anemia results in decreased oxygen-carrying capacity, worsening the burden of cerebral hypoxia in preterm infants. RBC transfusions increase cerebral oxygenation. Improved brain development may be supported by avoidance of cerebral hypoxia, although restrictive RBC transfusion strategies were associated with better long-term neurodevelopmental outcomes. Conclusions: This review demonstrated that anemia and RBC transfusions were associated with cerebral oxygenation, brain injury and development and NDO in preterm infants. Individualized care regarding RBC transfusions during NICU admission, with attention to cerebral tissue oxygen saturation, seems reasonable and needs further investigation to improve both short-term effects and long-term neurodevelopment of preterm infants.

Transfusions and neurodevelopmental outcomes in extremely low gestation neonates enrolled in the PENUT Trial: a randomized clinical trial

BACKGROUND

Outcomes of extremely low gestational age neonates (ELGANs) may be adversely impacted by packed red blood cell (pRBC) transfusions. We investigated the impact of transfusions on neurodevelopmental outcome in the Preterm Erythropoietin (Epo) Neuroprotection (PENUT) Trial population.

METHODS

This is a post hoc analysis of 936 infants 24-0/6 to 27-6/7 weeks' gestation enrolled in the PENUT Trial. Epo 1000 U/kg or placebo was given every 48 h × 6 doses, followed by 400 U/kg or sham injections 3 times a week through 32 weeks postmenstrual age. Six hundred and twenty-eight (315 placebo, 313 Epo) survived and were assessed at 2 years of age. We evaluated associations between BSID-III scores and the number and volume of pRBC transfusions.

RESULTS

Each transfusion was associated with a decrease in mean cognitive score of 0.96 (95% CI of [-1.34, -0.57]), a decrease in mean motor score of 1.51 (-1.91, -1.12), and a decrease in mean language score of 1.10 (-1.54, -0.66). Significant negative associations between BSID-III score and transfusion volume and donor exposure were observed in the placebo group but not in the Epo group.

CONCLUSIONS

Transfusions in ELGANs were associated with worse outcomes. We speculate that strategies to minimize the need for transfusions may improve outcomes.

IMPACT

Transfusion number, volume, and donor exposure in the neonatal period are associated with worse neurodevelopmental (ND) outcome at 2 years of age, as assessed by the Bayley Infant Scales of Development, Third Edition (BSID-III). The impact of neonatal packed red blood cell transfusions on the neurodevelopmental outcome of preterm infants is unknown. We speculate that strategies to minimize the need for transfusions may improve neurodevelopmental outcomes.

Neonatal red blood cell transfusion

Transfusions are more common in premature infants with approximately 40% of low birth weight infants and up to 90% of extremely low birth weight infants requiring red blood cell transfusion. Although red blood cell transfusion can be life-saving in these preterm infants, it has been associated with higher rates of complications including necrotizing enterocolitis, bronchopulmonary dysplasia, retinopathy of prematurity and possibly abnormal neurodevelopment. The main objective of this review is to assess current red blood cell transfusion practices in the neonatal intensive care unit, to summarize available neonatal transfusion guidelines published in different countries and to emphasize the wide variation in transfusion thresholds that exists for red blood cell transfusion. This review also addresses certain issues specific to red blood cell processing for the neonatal population including storage time, irradiation, cytomegalovirus (CMV) prevention strategies and patient blood management. Future research avenues are proposed to better define optimal transfusion practice in neonatal intensive care units.

Effect of High-Dose Erythropoietin on Blood Transfusions in Extremely Low Gestational Age Neonates: Post Hoc Analysis of a Randomized Clinical Trial

IMPORTANCE

Extremely preterm infants are among the populations receiving the highest levels of transfusions. Erythropoietin has not been recommended for premature infants because most studies have not demonstrated a decrease in donor exposure.

OBJECTIVES

To determine whether high-dose erythropoietin given within 24 hours of birth through postmenstrual age of 32 completed weeks will decrease the need for blood transfusions.

DESIGN, SETTING, AND PARTICIPANTS

The Preterm Erythropoietin Neuroprotection Trial (PENUT) is a randomized, double-masked clinical trial with participants enrolled at 19 sites consisting of 30 neonatal intensive care units across the United States. Participants were born at a gestational age of 24 weeks (0-6 days) to 27 weeks (6-7 days). Exclusion criteria included conditions known to affect neurodevelopmental outcomes. Of 3266 patients screened, 2325 were excluded, and 941 were enrolled and randomized to erythropoietin (n = 477) or placebo (n = 464). Data were collected from December 12, 2013, to February 25, 2019, and analyzed from March 1 to June 15, 2019.

INTERVENTIONS

In this post hoc analysis, erythropoietin, 1000 U/kg, or placebo was given every 48 hours for 6 doses, followed by 400 U/kg or sham injections 3 times a week through postmenstrual age of 32 weeks.

MAIN OUTCOMES AND MEASURES

Need for transfusion, transfusion numbers and volume, number of donor exposures, and lowest daily hematocrit level are presented herein.

RESULTS

A total of 936 patients (488 male [52.1%]) were included in the analysis, with a mean (SD) gestational age of 25.6 (1.2) weeks and mean (SD) birth weight of 799 (189) g. Erythropoietin treatment (vs placebo) decreased the number of transfusions (unadjusted mean [SD], 3.5 [4.0] vs 5.2 [4.4]), with a relative rate (RR) of 0.66 (95% CI, 0.59-0.75); the cumulative transfused volume (mean [SD], 47.6 [60.4] vs 76.3 [68.2] mL), with a mean difference of -25.7 (95% CI, 18.1-33.3) mL; and donor exposure (mean [SD], 1.6 [1.7] vs 2.4 [2.0]), with an RR of 0.67 (95% CI, 0.58-0.77). Despite fewer transfusions, erythropoietin-treated infants tended to have higher hematocrit levels than placebo-treated infants, most noticeable at gestational week 33 in infants with a gestational age of 27 weeks (mean [SD] hematocrit level in erythropoietin-treated vs placebo-treated cohorts, 36.9% [5.5%] vs 30.4% [4.6%] (P < .001). Of 936 infants, 160 (17.1%) remained transfusion free at the end of 12 postnatal weeks, including 43 in the placebo group and 117 in the erythropoietin group (P < .001).

CONCLUSIONS AND RELEVANCE

These findings suggest that high-dose erythropoietin as used in the PENUT protocol was effective in reducing transfusion needs in this population of extremely preterm infants.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01378273.

Effects of Liberal vs Restrictive Transfusion Thresholds on Survival and Neurocognitive Outcomes in Extremely Low-Birth-Weight Infants: The ETTNO Randomized Clinical Trial

IMPORTANCE

Red blood cell transfusions are commonly administered to infants weighing less than 1000 g at birth. Evidence-based transfusion thresholds have not been established. Previous studies have suggested higher rates of cognitive impairment with restrictive transfusion thresholds.

OBJECTIVE

To compare the effect of liberal vs restrictive red blood cell transfusion strategies on death or disability.

DESIGN, SETTING, AND PARTICIPANTS

Randomized clinical trial conducted in 36 level III/IV neonatal intensive care units in Europe among 1013 infants with birth weights of 400 g to 999 g at less than 72 hours after birth; enrollment took place between July 14, 2011, and November 14, 2014, and follow-up was completed by January 15, 2018.

INTERVENTIONS

Infants were randomly assigned to liberal (n = 492) or restrictive (n = 521) red blood cell transfusion thresholds based on infants' postnatal age and current health state.

MAIN OUTCOME AND MEASURES

The primary outcome, measured at 24 months of corrected age, was death or disability, defined as any of cognitive deficit, cerebral palsy, or severe visual or hearing impairment. Secondary outcome measures included individual components of the primary outcome, complications of prematurity, and growth.

RESULTS

Among 1013 patients randomized (median gestational age at birth, 26.3 [interquartile range {IQR}, 24.9-27.6] weeks; 509 [50.2%] females), 928 (91.6%) completed the trial. Among infants in the liberal vs restrictive transfusion thresholds groups, respectively, incidence of any transfusion was 400/492 (81.3%) vs 315/521 (60.5%); median volume transfused was 40 mL (IQR, 16-73 mL) vs 19 mL (IQR, 0-46 mL); and weekly mean hematocrit was 3 percentage points higher with liberal thresholds. Among infants in the liberal vs restrictive thresholds groups, the primary outcome occurred in 200/450 (44.4%) vs 205/478 (42.9%), respectively, for a difference of 1.6% (95% CI, -4.8% to 7.9%; P = .72). Death by 24 months occurred in 38/460 (8.3%) vs 44/491 (9.0%), for a difference of -0.7% (95% CI, -4.3% to 2.9%; P = .70), cognitive deficit was observed in 154/410 (37.6%) vs 148/430 (34.4%), for a difference of 3.2% (95% CI, -3.3% to 9.6%; P = .47), and cerebral palsy occurred in 18/419 (4.3%) vs 25/443 (5.6%), for a difference of -1.3% (95% CI, -4.2% to 1.5%; P = .37), in the liberal vs the restrictive thresholds groups, respectively. In the liberal vs restrictive thresholds groups, necrotizing enterocolitis requiring surgical intervention occurred in 20/492 (4.1%) vs 28/518 (5.4%); bronchopulmonary dysplasia occurred in 130/458 (28.4%) vs 126/485 (26.0%); and treatment for retinopathy of prematurity was required in 41/472 (8.7%) vs 38/492 (7.7%). Growth at follow-up was also not significantly different between groups.

CONCLUSIONS AND RELEVANCE

Among infants with birth weights of less than 1000 g, a strategy of liberal blood transfusions compared with restrictive transfusions did not reduce the likelihood of death or disability at 24 months of corrected age.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01393496.

Allogeneic cord blood transfusions prevent fetal haemoglobin depletion in preterm neonates. Results of the CB-TrIP study

Repeated red blood cell (RBC) transfusions in preterm neonates are associated with poor outcome and increased risk for prematurity-associated diseases. RBC transfusions cause the progressive replacement of fetal haemoglobin (HbF) by adult haemoglobin (HbA). We monitored HbF levels in 25 preterm neonates until 36 weeks of post-menstrual age (PMA); patients received RBC units from allogeneic cord blood (cord-RBCs) or from adult donors (adult-RBCs), depending on whether cord-RBCs were available. Primary outcome was HbF level at PMA of 32 weeks. Twenty-three neonates survived until this age: 14 received no transfusions, two only cord-RBCs, three only adult-RBCs and four both RBC types. HbF levels in neonates transfused with cord-RBCs were significantly higher than in neonates receiving adult-RBCs (P < 0·0001) or both RBC types (P < 0·0001). Superimposable results were obtained at PMA of 36 weeks. Every adult-RBCs transfusion increased the risk for an HbF in the lowest quartile by about 10-fold, whereas this effect was not evident if combined adult- and cord-RBCs were evaluated. Overall, these data show that transfusing cord-RBCs can limit the HbF depletion caused by conventional RBC transfusions. Transfusing cord blood warrants investigation in randomised trials as a strategy to mitigate the severity of retinopathy of prematurity (NCT03764813).

Neonatal clinical blood sampling led to major blood loss and was associated with bronchopulmonary dysplasia

AIM

Studies indicate that reduced foetal haemoglobin levels are related to increased neonatal morbidity rates. This study investigated the relationships between sampling-related blood loss and adult blood transfusions administered during postnatal days 1-14 and the development of severe neonatal morbidities in extremely preterm infants born before 28 weeks of gestation.

METHODS

The medical files of 149 extremely preterm infants born at two university hospitals in Sweden from 2013 to 2018 were investigated.

RESULTS

Blood sampling resulted in a 58% depletion of the endogenous blood volume postnatal days 1-14 (median 40.4 mL/kg, interquartile range 23.9-53.3 mL/kg) and correlated with the adult erythrocyte transfusion volume (r_S  = 0.870, P < .001). Sampling-related blood loss on postnatal days 1-7, adjusted for gestational age at birth and birth weight standard deviation score, was associated with the development of bronchopulmonary dysplasia (BPD) (odds ratio by a 10-unit increase 2.4, 95% confidence interval 1.1-5.4) (P = .03). No associations were found between blood sampling and intraventricular haemorrhage or necrotising enterocolitis in the full statistical model. The largest proportion of sampling-related blood was used for blood gas analyses (48.7%).

CONCLUSION

Diagnostic blood sampling led to major endogenous blood loss replaced with adult blood components and was associated with the development of BPD.

Neonatal Umbilical Arterial Catheter Removal Is Accompanied by a Marked Decline in Phlebotomy Blood Loss

BACKGROUND

Umbilical arterial catheters (UACs) are frequently used in critically ill neonates. UAC are convenient, reliable, and allow for caregiver convenience in performing painless arterial blood sampling. We hypothesized that UAC removal in extremely low birth weight (ELBW) neonates will result in significantly less phlebotomy blood loss (PBL) after correcting for severity of illness.

STUDY DESIGN AND METHODS

PBL was measured at a single center in 99 ELBW infants who survived to day 28. Individual infant's paired daily PBL for the two 24-h periods before and after UAC removal were compared using the paired t test. Daily PBL up to 7 days before and 7 days after UAC removal were compared using a logistic regression with mixed model analysis for repeated measures. Cumulative 28-day phlebotomy loss was evaluated by multiple linear regression analysis.

RESULTS

PBL 24 h before and after UAC removal were 1.7 mL (95% CI 1.5-1.9) and 0.9 mL (95% CI 0.8-1.0; p < 0.0001), respectively. Cumulative 28-day PBL increased by 2.2 mL (±0.7) per day that a UAC was present with or without correction for severity of illness (p < 0.001).

CONCLUSION

UAC removal is independently associated with a marked decline in PBL. We speculate the ease and convenience of UAC blood sampling lead to more frequent blood testing and greater PBL.

Patterns of phlebotomy blood loss and transfusions in extremely low birth weight infants

OBJECTIVE

Characterize frequency and volume of blood draws and transfusions in extremely low birth weight infants in the first 10 weeks of life.

STUDY DESIGN

We included infants with a birth weight <1000 g born 23 0/7-29 6/7 weeks gestational age (GA) and with a length of stay ≥10 weeks, admitted between 2014 and 2016 to a single neonatal intensive care unit.

RESULTS

Of 54 infants, median (25th, 75th percentile) GA and birth weight were 25 weeks (24, 26) and 665 g (587, 822), respectively. Median number of blood draws per infant decreased from 57 (49, 65) in week 1 to 12 (8, 22) in week 10. Median volume of blood extracted was 83 mL (70, 97), and median number of blood transfusions was 8 (5, 10).

CONCLUSIONS

This cohort experienced a high number and volume of blood draws. Draw frequency and transfusions decreased over the first 10 weeks of life.

Management of anaemia in pre-term infants

Pre-term infants have one of the highest transfusion requirements within the hospital-setting. The vast majority of blood transfusions performed in Neonatal Intensive Care Units (NICUs) are for medically stable pre-term infants with anaemia of prematurity, with the aim of improving oxygen delivery to the vital organs during the crucial phase of growth and development. However, despite the frequency of transfusion in this population, the potential benefits and harms of 'top up' transfusion are not fully understood, leading to practice variation between clinicians, institutions and countries. Significant advances have been made in the prevention of anaemia of prematurity, with recent emphasis on optimising infants' circulatory volume at birth via placental transfusion and preserving infants' own blood volume through innovative minimal sampling techniques. More research is urgently needed to establish optimal transfusion thresholds for these high-risk pre-term infants, for whom benefits as well as adverse outcomes may have consequences that extend for decades throughout the recipients' life-course. In this review, we will discuss some of the consensus and controversies regarding optimal management of anaemia in pre-term infants and highlight potential areas for future research.

Global incidence of bronchopulmonary dysplasia among extremely preterm infants: a systematic literature review

BACKGROUND

Infants born extremely preterm (<28 weeks gestational age (GA)) face a high risk of neonatal mortality. Bronchopulmonary dysplasia (BPD) is the most common morbidity of prematurity.

OBJECTIVE

To evaluate the global incidence of BPD among infants born extremely preterm.

DESIGN

A systematic review of the literature was conducted in Embase and MEDLINE (via PubMed) using a prespecified search strategy for BPD and prematurity. Observational studies published in English between 16 May 2006 and 16 October 2017 reporting on the occurrence of BPD in infants born <28 weeks GA were included.

RESULTS

Literature searches yielded 103 eligible studies encompassing 37 publications from Europe, 38 publications from North America, two publications from Europe and North America, 19 publications from Asia, one publication from Asia and North America, six publications from Oceania, and zero publications from Africa or South America. The reported global incidence range of BPD was 10-89% (10-73% in Europe, 18-89% in North America, 18-82% in Asia, and 30-62% in Oceania). When only population-based observational studies that defined BPD as requiring supplemental oxygen at 36 weeks postmenstrual age were included, the global incidence range of BPD was 17-75%. The wide range of incidences reflected interstudy differences in GA (which was inversely related to BPD incidence), birthweight, and survival rates across populations and institutions.

CONCLUSIONS

BPD is a common health morbidity occurring with extremely preterm birth. Further study of factors that impact incidence, aside from low GA, may help to elucidate modifiable risks.

Risk of Necrotizing Enterocolitis Following Packed Red Blood Cell Transfusion in Very Low Birth Weight Infants

OBJECTIVE

To evaluate the association between red blood cell (RBC) transfusion leading to necrotizing enterocolitis (NEC) within 48 h, known as transfusion-associated necrotizing enterocolitis (TANEC).

METHODS

A nested case-control study using historical data was conducted in the neonatal intensive care unit of Songklanagarind Hospital, Thailand. All very low birth weight (VLBW) infants delivered between November 2009 and July 2016 were enrolled. The infants were identified as RBC transfusion received and NEC developed. Logistic regression was used to evaluate risk factors for transfusion and the association between RBC transfusion and NEC.

RESULTS

Four hundred and forty-four VLBW infants were enrolled in the study. The median (interquartile range) gestational age was 29 (27, 31) wk. The overall incidence of NEC was 13%. Three (5.2%) of the NEC infants had TANEC. The infants who received RBC transfusion had a lower gestational age [odds ratio, OR 0.64; 95% confidence interval (95%CI) 0.57, 0.73, p < 0.001] and were more likely to have pneumonia (OR 9.86; 95%CI 5.02, 19.35, p < 0.001) or to have received H₂ blocker (OR 2.92; 95%CI 1.73, 4.93, p < 0.001). The ORs (95% CI) after adjusting for confounders, the association between RBC transfusion and NEC for transfusions ≤2 d, >2 to 4 d, and > 4 to 6 d prior to NEC were 1.83 (0.41, 8.16; p = 0.43), 1.7 (0.26, 11.16; p = 0.58) and 1.19 (0.31, 4.62; p = 0.80) respectively.

CONCLUSIONS

After controlling of confounders, no evidence of association was found between RBC transfusion and TANEC.

Association between hemoglobin concentrations at discharge from the neonatal intensive care unit with markers of neurodevelopmental outcomes in premature neonates

BACKGROUND

Premature neonates are often subjected to multiple transfusions with red blood cells during their hospitalization in the neonatal intensive care unit (NICU). The hemoglobin threshold for transfusion prior to discharge from the NICU varies significantly among different centers. The aim of the present study is to investigate the association between hemoglobin concentration at discharge with neurodevelopmental outcomes in premature neonates.

METHODS

Retrospective observation study with regression analysis was performed with follow up assessment in the neuro-developmental outpatient clinic at 30 months of adjusted age.

RESULTS

Data from 357 neonates born at less than 37 weeks' gestation were analyzed. Sensory and motor neurodevelopment at 30 months of adjusted age, were not associated with the hemoglobin concentration at discharge (p=0.5891 and p=0.4575, respectively). There was no association between the hemoglobin concentration at discharge with fine or gross motor development (p=0.1582 and p=0.3805, respectively). Hemoglobin concentration at discharge was not associated with poor neurodevelopmental outcomes up until 30 months of adjusted age.

CONCLUSIONS

The data of the present study indicate that the hemoglobin concentration of premature neonates at the time of discharge is not associated with poorer markers of neurodevelopmental outcomes at 30 months of adjusted age. Comorbidities such as BPD and IVH that are present to premature neonates were identified as potential risk factors for certain aspects of the neurodevelopment.

Enteral iron supplementation, red blood cell transfusion, and risk of bronchopulmonary dysplasia in very-low-birth-weight infants

BACKGROUND

Enteral iron supplementation and RBC transfusions are routinely administered to very-low-birth-weight (VLBW) infants, although the potential risks of these exposures have not been adequately quantified. This study evaluated the association between the cumulative dose of enteral iron supplementation, total volume of RBCs transfused, and risk of bronchopulmonary dysplasia (BPD) in VLBW infants.

STUDY DESIGN AND METHODS

Retrospective, multicenter observational cohort study in Atlanta, Georgia. Cumulative supplemental enteral iron exposure and total volume of RBCs transfused were measured until the age at assessment of BPD. Multivariable generalized linear models were used to control for confounding, and the reliability of the factors was assessed in 1000 bootstrap models.

RESULTS

A total of 598 VLBW infants were studied. In multivariable analyses, a greater cumulative dose of supplemental enteral iron exposure was associated with an increased risk of BPD (adjusted relative risk per 50-mg increase, 1.07; 95% confidence interval [CI], 1.02-1.11; p = 0.002). Similarly, a greater volume of RBCs transfused was associated with a higher risk of BPD (adjusted relative risk per 20-mL increase, 1.05; 95% CI, 1.02-1.07; p < 0.001). Both factors were reliably associated with BPD (>50%). Volume of RBCs transfused was similar to gestational age in reliability as a risk factor for BPD (present in 100% of models) and was more reliable than mechanical ventilation at 1 week of age.

CONCLUSION

The cumulative dose of supplemental enteral iron exposure and total volume of RBC transfusion are both independently associated with an increased risk of BPD in VLBW infants.