The Premature Infants in Need of Transfusion (PINT) study: a randomized, controlled trial of a restrictive (low) versus liberal (high) transfusion threshold for extremely low birth weight infants

Postnatal weight gain and retinopathy of prematurity in preterm infants: a population-based retrospective cohort study

OBJECTIVE

Infants who meet the screening guidelines for retinopathy of prematurity (ROP) based on birth weight and gestational age undergo serial ophthalmological examinations for its detection and treatment. However, <10% of patients require treatment, and less than half develop ROP. Poor postnatal weight gain has been reported to be a strong indicator of ROP development; however, the information regarding this is unclear. Therefore, this study aimed to determine the relationship between postnatal weight gain and ROP development in preterm infants.

METHODS

The data of 675 preterm infants with gestational age ≤32 weeks, who were hospitalized in our neonatal intensive care unit, were obtained retrospectively from file records. The infants' demographic characteristics, clinical findings, and weekly weight gain (g/kg/day) during the first 8 weeks were recorded. The univariate was used to examine the risk factors for ROP followed by multivariate regression.

RESULTS

The incidence of ROP in the infants included in the study was 41% (n = 278) and 13.3% (n = 37) of them required treatment. In the infants of the group that developed ROP, the mean birth weight and gestational age were significantly lower than those in the group that did not develop ROP (973 ± 288 and 1301 ± 349 g, p = 0.001 and 28.48 ± 1.95 and 30.08 ± 1.60 weeks, p = 0.001, respectively). As the gestational week and birth weight decreased, ROP development and the risk of ROP-requiring treatment increased. In the infants of the group that developed ROP, the mean weight gain in the postnatal third week was detected as significantly lower compared to those in the group that did not develop ROP (13.9 ± 8.2 and 15.4 ± 6.8 g, p = 0.034). On multiple logistic regression analysis, birth weight (<750 g) (odds ratio [OR], 8.67; 95% confidence interval [CI], 3.99-18.82, p = 0.001), blood transfusion (OR, 2.39; 95% CI, 1.34-4.24, p = 0.003), necrotizing enterocolitis (OR, 4.79; 95% CI, 1.05-26.85, p = 0.045), bronchopulmonary dysplasia (OR, 2.03; 95% CI, 1.22-3.36, p = 0.006), antenatal steroid therapy (OR, 1.60; 95% CI, 1.05-2.43, p = 0.028), surfactant administration (OR, 2.06; 95% CI, 1.32-3.2, p = 0.001) were independent risk factors for ROP development.

CONCLUSION

Postnatal weight gain may not be an accurate predictor of ROP development after adjusting for confounding factors. However, the analysis of independent risk factors that influenced the development of ROP revealed a statistically significant effect in cases of low birth weight, blood transfusion, necrotizing enterocolitis, bronchopulmonary dysplasia, and antenatal steroid and surfactant therapies. These findings may help ophthalmologists and neonatologists to pay special attention to this patient group during ROP scanning.

Decreasing Blood Transfusions in Premature Infants Through Quality Improvement

BACKGROUND AND OBJECTIVES

Packed red blood cell transfusions (pRBCT) in preterm infants have been associated with significant morbidity. Although infants <26 weeks' gestational age typically require several pRBCT, preterm infants born between 26 and 34 weeks' gestational age may also require pRBCT during their hospitalization that are potentially preventable. We aimed to reduce pRBCT in this population by 20%.

METHODS

This quality improvement project was conducted in the Duke University Hospital NICU between July 2018 and February 2023. Interventions included the implementation of evidence-based transfusion thresholds, supporting bone marrow erythropoiesis, and reducing laboratory specimen volumes by increasing capillary test panels. The rates per 1000 patient days for pRBCT (outcome measure), number of new patients initiated on erythropoietin (process measure), number of basic metabolic panels (process measure), and total capillary panels (process measure) were monitored during the project period. Statistical process control charts were used to observe trends over time.

RESULTS

Among infants born between 26 0/7 and 34 6/7 weeks' gestational age, the rate of pRBCT decreased from an average of 23.8 to 12.7 transfusions per 1000 patient days, which is a 46.6% decrease. Increases in the use of erythropoietin and capillary panels were observed, along with a decrease in the use of basic metabolic panels. There was no change in mortality or the rate of necrotizing enterocolitis. Improvement was sustained for 24 months after implementation.

CONCLUSIONS

pRBCT can be decreased in preterm infants born between 26 and 34 completed weeks' gestation through a combination of strategies utilizing quality improvement methodology.

Sex differences in the association of pretransfusion haemoglobin and cognition in preterm infants

OBJECTIVES

To assess sex-specific differences in the association between pre-transfusion haemoglobin values and early neurodevelopmental function.

DESIGN

Observational follow-up of infants with birth weights <1000 g and gestational ages 22-28 weeks who were enrolled in the NICHD Neonatal Research Network Transfusion of Prematures (TOP) Trial at 19 U.S. sites, 2012-2017.

MAIN OUTCOME MEASURES

Pretransfusion haemoglobin values were obtained longitudinally through 36 weeks' postmenstrual age. The infant's mean pretransfusion haemoglobin was used as a marker of degree of anaemia (n=1655 measures). Measures of brain function were obtained at 22-26 months' corrected age using the Bayley Scales of Infant & Toddler Development, third edition (BSID-III) (n=1290 BSID-III scores). Sex-specific estimates for the linear relation between pretransfusion haemoglobin and BSID-III scores were obtained from repeated-measures regression analysis, adjusted for gestational age, birth weight, study site, clinical characteristics, and demographic covariates.

RESULTS

The relation of pretransfusion haemoglobin with 24-month BSID-III scores showed significant, independent interactions with both (1) sex (p=0.046) and (2) retinopathy of prematurity (ROP; p=0.004). In 614 males, BSID-III scores were higher by 1.07 points per g/dL (95% CI 1.58 to 4.33; p=0.008), not differing significantly among the three subscales (cognitive, language and motor; p=0.94). In 247 infants with ROP, BSID-III scores were higher by 2.95 points per g/dL (95% CI 0.28 to 1.87; p<0.0001), uniformly across subscales (p=0.73). These associations were non-significant in 676 females (p=0.96) and 1043 infants without ROP (p=0.81).

CONCLUSIONS

This study demonstrates sex-specific associations between mean pretransfusion haemoglobin (a marker of the severity of anaemia throughout the neonatal intensive care unit [NICU] hospitalisation) and early neurodevelopmental function at 22-26 months' corrected age.

Clinical Practice Guideline for Red Blood Cell Transfusion Thresholds in Very Preterm Neonates

Importance

Red blood cell (RBC) transfusion is a common medical intervention to treat anemia in very preterm neonates; however, best transfusion practices, such as thresholds, remain uncertain.

Objective

To develop recommendations for clinicians on the use of RBC transfusions in very preterm neonates.

Evidence Review

An international steering committee reviewed evidence from a systematic review of 6 randomized clinical trials (RCTs) that compared high vs low hemoglobin-based or hematocrit-based transfusion thresholds. The steering committee reached consensus on certainty-of-evidence ratings and worked with a panel from stakeholder organizations on reviewing the evidence. With input from parent representatives and the stakeholder panel, the steering committee used the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach to develop recommendations.

Findings

A systematic review of 6 RCTs encompassing 3483 participants (1759 females [51.3%]; mean [SD] age range, 25.9-29.8 [1.5-3.0] weeks) was used as the basis of the recommendations. The ranges for higher hemoglobin concentration (liberal) vs lower hemoglobin concentration (restrictive) threshold study arms were similar across the trials. However, specific thresholds differed based on the severity of illness, which was defined using variable criteria in the trials. There was moderate certainty of evidence that low transfusion thresholds likely had little to no difference in important short-term and long-term outcomes. The recommended hemoglobin thresholds varied on the basis of postnatal week and respiratory support needs. At postnatal weeks 1, 2, and 3 or more, for neonates on respiratory support, the recommended thresholds were 11, 10, and 9 g/dL, respectively; for neonates on no or minimal respiratory support, the recommended thresholds were 10, 8.5, and 7 g/dL, respectively (to convert hemoglobin to grams per liter, multiply by 10.0).

Conclusions and Relevance

This consensus statement recommends a restrictive RBC transfusion strategy, with moderate certainty of evidence, for preterm neonates with less than 30 weeks' gestation.

Effect of Minimization of Early Blood Sampling Losses Among Extremely Premature Neonates: A Randomized Clinical Trial

OBJECTIVE

To evaluate the effect of blood sampling stewardship on transfusion requirements among infants born extremely preterm.

STUDY DESIGN

In this single-center, randomized controlled trial (RCT), infants born at <28 weeks of gestation and birth weight of <1000 g were randomized at 24 hours of age to two different blood sampling approaches: restricted sampling (RS) vs conventional sampling (CS). The stewardship intervention in the RS group included targeted reduction in blood sampling volume and frequency and point of care testing methods in the first 6 weeks after birth. Both groups received early recombinant erythropoietin from day three of age. Primary outcome was the rate of early red blood cell (RBC) transfusions in the first six postnatal weeks.

RESULTS

A total of 102 infants (mean gestational age: 26 weeks; birth weight: 756 g) were enrolled. Fidelity to the sampling protocol was achieved in 95% of the infants. Sampling losses in the first 6 weeks were significantly lower in the RS group (16.8 ml/kg vs 23.6 ml/kg, P < .001). The RS group had a significantly lower rate of early postnatal RBC transfusions (41% vs 73%, RR: 0.56 [0.39-0.81], P = .001). The hazard of needing a transfusion during neonatal intensive care unit (NICU) stay was reduced by 55% by RS. Mortality and neonatal morbidities were similar between the two groups.

CONCLUSION

Minimization of blood sampling losses by approximately one-third in the first 6 weeks after birth leads to substantial reduction in the early red blood cell transfusion rate in infants born extremely preterm and weighing <1000 g at birth.

TRIAL REGISTRATION

http://www.ctri.nic.in (CTRI/2020/01/022  964).

Association of low hemoglobin at birth and neurodevelopmental outcomes in preterm neonates ≤28 weeks' gestation: a retrospective cohort study

OBJECTIVE

To compare neurodevelopmental outcomes at 18-24 months corrected age (CA) for preterm infants who had hemoglobin levels <120 g/l versus those with hemoglobin level ≥120 g/l at birth.

METHODS

We included infants of ≤28 weeks gestational age (GA) born between January 2009 and June 2018. The primary outcome was neurodevelopmental impairment (NDI) at 18-24 months. Multivariable logistic regression was applied to determine the association.

RESULTS

Of the 2351 eligible neonates, 351 (14.9%) had hemoglobin levels <120 g/L at birth. Of the 2113 surviving infants, 1534 (72.5%) underwent developmental follow-up at 18-24 months CA. There was no statistically significant difference in ND outcomes between the two groups. The composite outcome of death or NDI was significantly higher in the low hemoglobin group.

CONCLUSION

In preterm infants ≤28 weeks GA, initial hemoglobin <120 g/L at birth was not associated with neurodevelopmental impairment at 18-24 months CA among survivors.

Impact of Delayed Cord Clamping on Red Blood Cell Transfusion and Related Outcomes in Very Low Birth Weight Infants

OBJECTIVE

Delayed cord clamping (DCC) for 30 to 60 seconds after birth facilitates placental transfusion, increases blood volume, and decreases red blood cell (RBC) transfusion in preterm infants. Study objective was to determine (1) RBC transfusion burden over a 5-year period, (2) impact of DCC practice on RBC transfusions, and (3) association of RBC transfusion on outcomes in very low birthweight (VLBW) preterm infants.

STUDY DESIGN

A retrospective medical chart review was performed in 787 VLBW infants between 2016 and 2020. Demographic factors, DCC status, number of RBC transfusions, and neonatal outcomes were determined in eligible infants. Adjusted association between DCC, RBC transfusion, and outcomes were determined using logistic and linear regression methods.

RESULTS

Of the 538 eligible VLBW infants, 62% (N = 332) received RBC transfusions. Proportion receiving RBC transfusion were significantly higher for infants <1,000 g (N = 217, 65.4%) and gestational age (GA) <29 weeks (N = 256, 77.1%) than larger (1,001-1,250 g, N = 77, 23.2% and 1,251-1,500 g, N = 38, 11.4%) and older GA ≥ 29 weeks' infants (N = 76, 22.9%, p < 0.05). Of the 81/538 (15.1%) who received DCC, 48 (59.2%) received no RBC transfusion (p < 0.001). In multivariable logistic regression analysis, preterm infants with DCC were 55% less likely to receive RBC transfusions as compared with infants with no DCC. At any given GA, the number of RBC transfusions in preterm infants with DCC was 25% lower as compared with infants without DCC (p < 0.05). Transfusion was associated with 8-fold increased odds for bronchopulmonary dysplasia and 4-fold increased odds for medical and surgically treated patent ductus arteriosus compared with no transfusion. There was no significant association of transfusion with neonatal sepsis, laser treated retinopathy of prematurity, necrotizing enterocolitis, and intraventricular hemorrhage.

CONCLUSION

DCC was significantly associated with reduced RBC transfusion, but fewer preterm infants received DCC. Further research is needed to explore the feasibility of providing neonatal resuscitation during DCC in preterm infants.

KEY POINTS

· Delayed cord clamping significantly reduced the need for RBC transfusions.. · Fewer very preterm infants received DCC.. · Future research is needed to explore feasibility of neonatal resuscitation during DCC..

Transfusion strategies for neonates: current perspectives

Background

Blood transfusion intervention has been proven to be a crucial therapeutic aid for preterm infants with serious morbidities such as sepsis, intraventricular hemorrhage, and cardiopulmonary insufficiencies. However, blood transfusion practices have also been shown to cause significant adverse outcomes, which may negate the therapeutic effect of the intervention. To address the varying policies regarding the administration of blood products, healthcare professionals have adopted a consensus-based approach. The absence of a standard protocol has resulted in conflicting outcomes in previous clinical studies.

Objective

This study aimed to evaluate the effectiveness of blood transfusion practices in preterm infants by analyzing past clinical research and identifying the current trends that have emerged as a result of recent trials.

Results

Recent trials have demonstrated comparable trends in mortality rates and other primary outcomes, including retinopathy of prematurity, intraventricular hemorrhage, bronchopulmonary dysplasia, and brain injury, following transfusion of blood products in both groups. Nevertheless, employing restrictive thresholds rather than adopting a liberal approach can reduce these outcomes.

Conclusion

The current literature does not provide clear support for either technique as opposing and contradictory results are evident. However, there is a slight inclination toward the restrictive transfusion threshold due to recent trials, which warrants further in-depth investigation into this issue.

Blood Product Transfusions for Children in the Perioperative Period and for Critically Ill Children

BACKGROUND

Approximately 1% to 2% of all hospitalized children receive a transfusion of blood products, in Germany as in other countries. High-quality scientific evidence on transfusions in children is scarce. The available evidence is discussed in this review.

METHODS

This review is based on publications on blood product transfusions in children that were retrieved by a literature search, including clinical studies, international guideline recommendations, the recommendations of the German cross-sectional guideline, and results of other recent, relevant publications.

RESULTS

A restrictive transfusion strategy is recommended for all children, including those who are critically ill. Randomized controlled trials have shown that a restrictive strategy for erythrocyte concentrate transfusion in the intensive care unit is safe for children, including neonates. No robust data are available to enable the definition of a suitable threshold for the intraoperative administration of red blood cell concentrates in children undergoing extracardiac surgery. On the basis of studies from pediatric intensive care units, transfusions for hemodynamically stable children with a hemoglobin concentration of more than 7 g/dL are recommended only in exceptional cases. Therapeutic plasma is not recommended as volume replacement, except in massive transfusion. Platelet concentrate transfusions are indicated in case of active hemorrhage, and only rarely for prophylaxis.

CONCLUSION

There is a broad lack of evidence from randomized controlled trials concerning the indications for transfusions in children. A restrictive transfusion strategy, which has been found safe in the intensive-care setting, is favored by the guidelines in the perioperative setting as well. Further studies are needed to evaluate transfusion triggers and indications for all types of blood products, especially therapeutic plasma. Until more evidence is available, physicians should be aware of what the current evidence supports, and blood products should be given restrictively, and not prophylactically.

Association between neurodevelopmental outcomes and concomitant presence of NEC and IVH in extremely low birth weight infants

OBJECTIVE

To quantify the association between necrotizing enterocolitis (NEC) and neurodevelopmental disability (NDI) in extremely low birth weight (ELBW) infants with intraventricular hemorrhage (IVH).

STUDY DESIGN

ELBW survivors born 2011-2017 and evaluated at 16-26 months corrected age in the Vermont Oxford Network (VON) ELBW Follow-Up Project were included. Logistic regression determined the adjusted relative risk (aRR) of severe NDI in medical or surgical NEC compared to no NEC, stratified by severity of IVH.

RESULTS

Follow-up evaluation occurred in 5870 ELBW survivors. Compared to no NEC, medical NEC had no impact on NDI, regardless of IVH status. Surgical NEC increased risk of NDI in patients with no IVH (aRR 1.69; 95% CI 1.36-2.09), mild IVH (aRR 1.36;0.97-1.92), and severe IVH (aRR 1.35;1.13-1.60).

CONCLUSIONS

ELBW infants with surgical NEC carry increased risk of neurodevelopmental disability within each IVH severity stratum. These data describe the additive insult of surgical NEC and IVH on neurodevelopment, informing prognostic discussions and highlighting the need for preventative interventions.

Retrospective cohort study of neonatal blood transfusion in China

BACKGROUND

Blood transfusion therapy is extremely important for certain neonatal diseases, but the threshold for neonatal blood transfusion is not the same in different countries. Until now, clinical studies to determine the suitable threshold for newborns in China are lacking. Therefore, it is of high importance to establish a multi-center cohort study to explore appropriate transfusion thresholds for newborns in China.

METHODS

This retrospective cohort study investigated neonatal blood transfusion therapy administered from January 1, 2017 to June 30, 2018, with the aim of evaluating the effect of restricted and nonrestricted blood transfusion on neonatal health. The subjects were enrolled in 46 hospitals in China. A total of 5669 neonatal cases were included in the study. Clinical diagnosis and transfusion treatment of these neonates were collected and the data were retrospectively analyzed. The neonates were followed up 1 week and 1 month after leaving the hospital. The newborns' and their mothers' data were collected containing 280 variables in the database. The primary outcome of the study was mortality, and the secondary outcomes were complications, hospital stays, NICU hospital stays and hospital costs.

RESULTS

Results from the < 1500 g group showed that there was a higher mortality rate in the restricted transfusion group (11.41%) when compared with the non-restricted transfusion group (5.12%) (P = 0.000). Among the secondary outcomes, the restricted transfusion group had fewer costs. Results from the 1500-2500 g group showed that the mortality rates of the restricted and non-restricted transfusion groups were 3.53% and 4.71%, respectively, however there was no statistical significance between the two groups (P = 0.345). Among the secondary outcomes, the restricted transfusion group had fewer hospital stays, NICU hospital stays and hospital costs. The incidence of necrotizing enterocolitis was lower in the restricted transfusion group (OR, 2.626; 95% confidence interval [CI], 1.445 to 4.773; P = 0.003). The results from the ≥ 2500 g restricted transfusion group suggested that the mortality rate of (3.02%) was significantly lower than that of non-restricted transfusion group (9.55%) (P = 0.000). Among the secondary outcomes, the restricted transfusion group had fewer hospital stays and hospital costs. The incidence of retinopathy of prematurity was lower in the restricted transfusion group (OR, 4.624; 95% confidence interval [CI], 2.32 to 9.216; P = 0.000).

CONCLUSIONS

Current transfusion protocols for newborns weighing less than 1500 g may be inappropriate and lead to higher mortality. The current transfusion threshold performed better for the other two weight groups.

Thresholds for Red Blood Cell Transfusion in Preterm Infants: Evidence to Practice

Rapid blood loss with circulatory shock is dangerous for the preterm infant as cardiac output and oxygen-carrying capacity are simultaneously imperilled. This requires prompt restoration of circulating blood volume with emergency transfusion. It is recommended that clinicians use both clinical and laboratory responses to guide transfusion requirements in this situation. For preterm infants with anemia of prematurity, it is recommended that clinicians use a restrictive algorithm from one of two recently published clinical trials. Transfusion outside these algorithms in very preterm infants is not evidence-based and is actively discouraged.

Blood Donor Sex and Outcomes in Transfused Infants

Red blood cell transfusion is common in neonatal intensive care. Multiple trials have evaluated different thresholds for when to administer red blood cell transfusion. In contrast, there has been less focus on studies of the characteristics of red blood cells transfused into neonates. In this review, the authors summarize the emerging literature on the potential impact of the sex of blood donors on outcomes in transfused neonates using a systematic search strategy. The authors review the uncertainty generated from studies with conflicting findings and discuss considerations regarding the impact of blood donor sex and other characteristics on neonatal outcomes.

Erythrocyte transfusions are associated with retinopathy of prematurity in extremely low gestational age newborns

AIM

Retinopathy of prematurity (ROP) is a major morbidity in preterm infants causing visual impairment including blindness. Prevention and timely treatment are critical. We investigated the potential role of red blood cell (RBC) transfusions as risk factor for ROP development.

METHODS

Retrospective cohort study of data from 68 tertiary level neonatal intensive care units in Germany. Preterm infants born at 22 + 0 to 28 + 6 weeks of gestation between January 2009 and December 2021 were enrolled.

RESULTS

We included n = 12 565 infants. Prevalence of any ROP was 49.2% with most infants being diagnosed with stage 1 (21.5%) and 2 disease (17.2%). ROP stage 3 was present in 10.2%, stage 4 in 0.3%, and ROP requiring treatment in 6.6%. Infants with ROP had significantly more frequently a history of RBC transfusions. Adjusting for confounders, RBC transfusions were associated with increased odds of ROP (OR 1.4, p < 0.001), ROP progression (OR 2.1, p < 0.01) and ROP requiring treatment (OR 3.6, p < 0.001). Restrictive transfusion approaches correlated with decreased (OR 0.7, p < 0.001), liberal regimes with increased odds (OR 1.2, p = 0.001).

CONCLUSION

The present study confirmed an association of RBC transfusions and ROP. Our findings emphasise the need for anaemia prevention and critical re-evaluation of transfusion practices in preterm infants.

Anemia, Iron Supplementation, and the Brain

The developing brain is particularly vulnerable to extrinsic environmental events such as anemia and iron deficiency during periods of rapid development. Studies of infants with postnatal iron deficiency and iron deficiency anemia clearly demonstrated negative effects on short-term and long-term brain development and function. Randomized interventional trials studied erythropoiesis-stimulating agents and hemoglobin-based red blood cell transfusion thresholds to determine how they affect preterm infant neurodevelopment. Studies of red blood cell transfusion components are limited in preterm neonates. A biomarker strategy measuring brain iron status and health in the preanemic period is desirable to evaluate treatment options and brain response.

New frontiers in neonatal red blood cell transfusion research

Red blood cell (RBC) transfusions are common in neonates requiring intensive care. Recent studies have compared restricted versus liberal transfusion guidelines, but limitations exist on evaluations of outcomes in populations that never required a transfusion compared to those receiving any transfusion. Although there are well-established risks associated with RBC transfusions, new data has emerged that suggests additional clinically relevant associations, including adverse neurodevelopmental outcomes, donor sex differences, and inflammation or immunosuppression. Further research is needed to delineate the magnitude of these risks and to further improve the safety of transfusions. The goal of this review is to highlight underappreciated, yet clinically important risks associated with neonatal RBC transfusions and to introduce several areas in which neonates may uniquely benefit from alterations in practice.

Reticulocyte Count: The Forgotten Factor in Transfusion Decisions for Extremely Low Birth Weight Infants

OBJECTIVE

Extremely low birth weight (ELBW) infants often receive transfusions of packed red blood cells (PRBCs). Long-term outcomes of infants treated with liberal versus restricted transfusion criteria have been evaluated with conflicting results. Clinicians incorporate a reticulocyte count (RC) in their transfusion decisions. There is a lack of information on reference ranges for RCs in growing ELBW infants and whether infant's chronologic age or corrected gestational age (GA) generates a specific trend in the RCs. Our aim was to evaluate the levels of RCs obtained from ELBW infants over the course of the initial hospitalization.

STUDY DESIGN

A retrospective chart review of ELBW infants treated in the neonatal intensive care unit (NICU) and had RCs performed. We analyzed the RCs to observe trends based on the chronologic age and corrected GA.

RESULTS

A total of 738 RCs were analyzed. A positive trend in RCs that reached a peak at 32 to 34 weeks' corrected GA and then experienced a downward trend was observed.

CONCLUSION

Our report examines a very common hematologic test that is theoretically helpful but is in need of guidelines concerning the appropriate frequency of testing and its utility in making transfusion decisions in ELBW infants.

KEY POINTS

· RCs should help in making transfusion decisions for ELBW infants.. · No current reference ranges for RC in this population.. · No current reference ranges for RC based on GA and postnatal age..

Preterm Infants off Positive Pressure Respiratory Support Have a Higher Incidence of Occult Cerebral Hypoxia

OBJECTIVE

To use cerebral near-infrared spectroscopy (NIRS) to quantify occult cerebral hypoxia across respiratory support modes in preterm infants.

STUDY DESIGN

In this prospective, longitudinal, observational study, infants ≤32 weeks gestation underwent serial pulse oximetry (oxygen saturation [SpO2]) and cerebral NIRS monitoring (4-6 hours per session) following a standardized recording schedule (daily for 2 weeks, every other day for 2 weeks, then weekly until 35 weeks corrected gestational age). Four calculations were made: median cerebral saturation, median cerebral hypoxia burden (proportion of NIRS samples below the hypoxia threshold [<67%]), median systemic saturation, and median systemic hypoxia burden (proportion of SpO2 samples below the desaturation threshold [<85%]). During each recording session, respiratory support mode was noted (room air, low-flow nasal cannula, high-flow nasal cannula, noninvasive positive pressure ventilation, continuous positive airway pressure, and invasive ventilation).

RESULTS

There were 1013 recording sessions made from 174 infants with a median length of 6.9 hours. Although the systemic (SpO2) hypoxia burden was significantly greater for infants on the highest respiratory support (invasive and noninvasive positive pressure ventilation), the cerebral hypoxia burden was significantly greater during recording sessions made on the lowest respiratory support (8% for room air; 29% for low-flow nasal cannula).

CONCLUSIONS

Premature infants on the highest levels of respiratory support have less cerebral hypoxia than those on lower respiratory support. These results raise concern about unrecognized cerebral hypoxia during lower acuity periods of neonatal intensive care unit hospitalization and adverse outcomes.

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.

Usefulness of Children's Hospital of Philadelphia ROP (CHOP ROP) model in the prediction of type 1 ROP

Purpose

Children's Hospital of Philadelphia retinopathy of prematurity (CHOP ROP) model can be used to predict ROP, a leading cause of childhood blindness, using risk factors such as postnatal weight gain, birth weight (BW), and gestation age (GA). The purpose of this study was to determine the usefulness of the CHOP ROP for the prediction of treatable ROP.

Methods

This was a prospective observational study. Babies <34 weeks of GA, BW <2000 grams, and GA 34-36 weeks with risk factors such as respiratory distress syndrome (RDS) were included; ROP screening, follow-up, and treatment were performed based on national guidelines. The average daily postnatal weight gain was measured, and the CHOP nomogram was plotted. Babies were categorized as high risk or low risk based on the "CHOP" alarm. The sensitivity and specificity of the CHOP ROP for the detection of treatable ROP were determined. In case of poor sensitivity, a new cutoff alarm level was planned using logistic regression analysis.

Results

Of 62 screened infants, 23 infants did not fulfill the criteria of the CHOP algorithm and were excluded. Thus, in the study on 39 infants, the predictive model with an alarm level of 0.014 had 100% specificity and 20% sensitivity. With the "new" alarm level (cutoff) of 0.0003, the CHOP nomogram could detect all the infants who developed treatable ROP, that is, sensitivity increased to 100% but specificity decreased to 10.5%.

Conclusion

The CHOP ROP model with a cutoff point (0.014) performed poorly in predicting severe ROP in the study. Thus, there is a need to develop inclusive and more sensitive tailor-made algorithms.

Red Blood Cell Transfusion, Anemia, Feeding, and the Risk of Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a leading cause of morbidity and mortality in preterm infants. Severe anemia and red blood cell (RBC) transfusion are associated with gut inflammation and injury in preclinical models and observational studies. However, there is uncertainty about the causal role of these factors in the pathogenesis of NEC. Observational studies have shown that withholding feeding during RBC transfusion may reduce the risk of NEC, although confirmatory data from randomized trials are lacking. In this review, we summarize data on feeding during RBC transfusion and its role in NEC and highlight ongoing randomized trials.

Impact of level of neonatal care on phlebotomy and blood transfusion in extremely low birthweight infants: a prospective, multicenter, observational study

Objectives

To explore the level of neonatal care on cumulative phlebotomy loss (cPL) and red cell transfusions in extremely low birthweight [ELBW; birthweight (BW) <1,000 g] infants, up to 40 weeks post-conceptual age (PCA). The secondary objective was to determine the associations between cPL and number of transfusions and between transfusions and hospital outcomes.

Methods

A prospective, comparative, observational study was conducted in two level IV and two level III neonatal intensive care units (NICUs) in Thailand. Daily cPL volume and number of blood tests were recorded. Descriptive data are reported as frequency and percentage for categorical variables and median [25th percentile (P25), 75th percentile (P75)] for continuous data according to the data distribution. A p-value <0.05 was considered statistically significant.

Results

210 ELBW infants were included; 99 and 111 were admitted to level IV and level III NICUs, respectively. Birth weight of level IV infants was lower 780.0 [660.0, 875.0] vs. 865.0 [723.0, 930.0] g; p < 0.001]. Initial group hematocrits were similar (43.1% vs. 44.0%, p = 0.47). cPL for each infant was 28.1 [16.5, 46.4] ml. Level IV infants had more tests (n = 89 [54, 195] vs. 59 [37, 88], p < 0.001). Counterintuitively, there was a lower cPL trend in level IV infants, but this was insignificant (19.6 [12.3, 52.3] vs. 28.9 [19.3, 45.3] ml; p = 0.06). The number of transfusions in both NICUs was similar 4 [2, 6], with a strong correlation between cPL and number of transfusions (r = 0.79, p < 0.001). Transfusions were significantly associated with bronchopulmonary dysplasia [BPD; adjusted RR (95% CI): 2.6 (1.2, 5.3), p = 0.01].

Conclusions

Level IV NICUs conducted more blood tests in ELBW infants without a difference in cPL, and number of transfusions. Cumulative PL correlated with number of transfusions and was associated with BPD risk. Minimizing cPL by point-of-care tests and restrictive transfusion criteria, may reduce need for transfusion.

Measuring gut perfusion and blood flow in neonates using ultrasound Doppler of the superior mesenteric artery: a narrative review

The gut is a relatively silent organ in utero but takes on a major role after birth for the absorption and digestion of feed for adequate nutrition and growth. The neonatal circulation undergoes a transition period after birth, and gut perfusion increases rapidly to satisfy the oxygen demand and consumption. If this process is compromised at any stage, preterm and fetal growth restricted infants are at particular risk of gut tissue injury secondary to hypoxia, leading to necrotizing enterocolitis. Feeding can also be a challenge in these high-risk groups due to gut dysmotility. Superior mesenteric artery (SMA) Doppler is a safe, bedside investigation that could rapidly aid clinicians with feeding strategies and in monitoring high-risk infants. This article aims to establish normal patterns of gut blood flow velocity in neonates using SMA Doppler and reviews how it might be used clinically in pathologic states.

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.

Red Blood Cell Transfusion Thresholds for Anemia of Prematurity

Anemia of prematurity affects the majority of preterm infants, particularly extremely low birthweight infants. Anemia of prematurity arises from both innate and iatrogenic causes and results in more than 80% of extremely preterm infants receiving red blood cell transfusions during the first month after birth. Multiple randomized controlled trials were conducted to evaluate the effect of using lower versus higher transfusion thresholds based on hemoglobin levels. These trials showed no difference in the primary outcome of neurodevelopmental impairment at 2 years of age between lower and higher thresholds. However, some uncertainties about transfusion thresholds remain. This review elaborates the following: 1) the etiology, prevention, and treatment of anemia of prematurity with a focus on red blood cell transfusions, 2) the history of randomized controlled trials on the treatment of anemia of prematurity, and 3) limitations of the evidence and remaining questions about thresholds for red blood cell transfusions in preterm infants.

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.

Interventions to Reduce Severe Brain Injury Risk in Preterm Neonates: A Systematic Review and Meta-analysis

Importance

Interventions to reduce severe brain injury risk are the prime focus in neonatal clinical trials.

Objective

To evaluate multiple perinatal interventions across clinical settings for reducing the risk of severe intraventricular hemorrhage (sIVH) and cystic periventricular leukomalacia (cPVL) in preterm neonates.

Data Sources

MEDLINE, Embase, CENTRAL (Cochrane Central Register of Controlled Trials), and CINAHL (Cumulative Index to Nursing and Allied Health Literature) databases were searched from inception until September 8, 2022, using prespecified search terms and no language restrictions.

Study Selection

Randomized clinical trials (RCTs) that evaluated perinatal interventions, chosen a priori, and reported 1 or more outcomes (sIVH, cPVL, and severe brain injury) were included.

Data Extraction and Synthesis

Two co-authors independently extracted the data, assessed the quality of the trials, and evaluated the certainty of the evidence using the Cochrane GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach. Fixed-effects pairwise meta-analysis was used for data synthesis.

Main Outcomes and Measures

The 3 prespecified outcomes were sIVH, cPVL, and severe brain injury.

Results

A total of 221 RCTs that assessed 44 perinatal interventions (6 antenatal, 6 delivery room, and 32 neonatal) were included. Meta-analysis showed with moderate certainty that antenatal corticosteroids were associated with small reduction in sIVH risk (risk ratio [RR], 0.54 [95% CI, 0.35-0.82]; absolute risk difference [ARD], -1% [95% CI, -2% to 0%]; number needed to treat [NNT], 80 [95% CI, 48-232]), whereas indomethacin prophylaxis was associated with moderate reduction in sIVH risk (RR, 0.64 [95% CI, 0.52-0.79]; ARD, -5% [95% CI, -8% to -3%]; NNT, 20 [95% CI, 13-39]). Similarly, the meta-analysis showed with low certainty that volume-targeted ventilation was associated with large reduction in risk of sIVH (RR, 0.51 [95% CI, 0.36-0.72]; ARD, -9% [95% CI, -13% to -5%]; NNT, 11 [95% CI, 7-23]). Additionally, early erythropoiesis-stimulating agents (RR, 0.68 [95% CI, 0.57-0.83]; ARD, -3% [95% CI, -4% to -1%]; NNT, 34 [95% CI, 22-67]) and prophylactic ethamsylate (RR, 0.68 [95% CI, 0.48-0.97]; ARD, -4% [95% CI, -7% to 0%]; NNT, 26 [95% CI, 13-372]) were associated with moderate reduction in sIVH risk (low certainty). The meta-analysis also showed with low certainty that compared with delayed cord clamping, umbilical cord milking was associated with a moderate increase in sIVH risk (RR, 1.82 [95% CI, 1.03-3.21]; ARD, 3% [95% CI, 0%-6%]; NNT, -30 [95% CI, -368 to -16]).

Conclusions and Relevance

Results of this study suggest that a few interventions, including antenatal corticosteroids and indomethacin prophylaxis, were associated with reduction in sIVH risk (moderate certainty), and volume-targeted ventilation, early erythropoiesis-stimulating agents, and prophylactic ethamsylate were associated with reduction in sIVH risk (low certainty) in preterm neonates. However, clinicians should carefully consider all of the critical factors that may affect applicability in these interventions, including certainty of the evidence, before applying them to clinical practice.

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.

Survey of transfusion practices in preterm infants in Europe

BACKGROUND

Preterm infants commonly receive red blood cell (RBC), platelet and fresh frozen plasma (FFP) transfusions. The aim of this Neonatal Transfusion Network survey was to describe current transfusion practices in Europe and to compare our findings to three recent randomised controlled trials to understand how clinical practice relates to the trial data.

METHODS

From October to December 2020, we performed an online survey among 597 neonatal intensive care units (NICUs) caring for infants with a gestational age (GA) of <32 weeks in 18 European countries.

RESULTS

Responses from 343 NICUs (response rate: 57%) are presented and showed substantial variation in clinical practice. For RBC transfusions, 70% of NICUs transfused at thresholds above the restrictive thresholds tested in the recent trials and 22% below the restrictive thresholds. For platelet transfusions, 57% of NICUs transfused at platelet count thresholds above 25×10⁹/L in non-bleeding infants of GA of <28 weeks, while the 25×10⁹/L threshold was associated with a lower risk of harm in a recent trial. FFP transfusions were administered for coagulopathy without active bleeding in 39% and for hypotension in 25% of NICUs. Transfusion volume, duration and rate varied by factors up to several folds between NICUs.

CONCLUSIONS

Transfusion thresholds and aspects of administration vary widely across European NICUs. In general, transfusion thresholds used tend to be more liberal compared with data from recent trials supporting the use of more restrictive thresholds. Further research is needed to identify the barriers and enablers to incorporation of recent trial findings into neonatal transfusion practice.

Comparative efficacy and safety of restrictive versus liberal transfusion thresholds in anemic preterm infants: a meta-analysis of 12 randomized controlled trials

The comparative efficacy and safety of restrictive with liberal transfusion thresholds remain controversial in anemic preterm infants. This meta-analysis aimed to compare the efficacy and safety of these two transfusion thresholds for anemic preterm infants. We searched PubMed, Embase, Cochrane Library, and China National Knowledge Infrastructure (CNKI) for relevant randomized controlled trials (RCTs) comparing restrictive with liberal transfusion thresholds in anemic preterm infants through April 30, 2022. Two independent investigators screened literature, extracted data, and appraised the methodological quality of eligible studies. Meta-analysis was conducted using RevMan version 5.3.5. Twelve RCTs with 4380 preterm infants were included. Liberal transfusion threshold significantly increased the level of hemoglobin after transfusion (mean difference (MD): -10.03; 95% confidence interval (CI): -15.98 to -4.08; p=0.001; I²=94%) and hematocrit (MD: -3.62; 95%CI: -6.78 to -0.46; p=0.02; I²=80%) compared with restrictive transfusion. Infants' age at first transfusion in restrictive transfusion group was higher than that of infants in liberal transfusion group (MD: 5.08; 95%CI: 2.27 to7.89; p=0.004; I²=54%); however, restrictive transfusion was associated with more time on supplemental oxygen (MD: 3.56; 95%CI: 1.93 to 5.18; p<0.001; I²=62%) and ventilator or CPAP (MD: 3.31; 95%CI: 1.42 to 5.20; p=0.006; I²=75%). For the remaining outcomes, two transfusion strategies were comparable. Furthermore, a series of sensitivity analyses confirmed the robustness of the level of hemoglobin after transfusion, age at first transfusion, time on ventilator or CPAP, and safety outcomes. Evidence with substantial heterogeneity indicates that liberal and restrictive transfusion thresholds are effective and safe blood cell transfusion strategies in anemic preterm infants, but the liberal strategy may be more effective in shortening the length of necessary respiratory support.

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.

Relationship of Early Anemia with Neurodevelopment and Brain Injury in Very Low Birth Weight Preterm Infants-A Prospective Cohort Study

Anemia is associated with neurodevelopmental delays and brain injury in infants and toddlers, but whether early anemia has a similar effect in neonatal preterm infants is largely unknown. Thus, this study aimed to determine the relationship of early anemia with neurodevelopment and brain injury in very-low-birth-weight (VLBW) preterm infants within the neonatal period. A prospective cohort study including 110 VLBW preterm infants was conducted in Southern China from 2016 to 2018. All participants were followed from birth to 1 month corrected age. Early anemia is defined as hemoglobin of ≤145 g/L within the first week after birth. The non-anemic group (control group, N = 55) was 1:1 matched with the early anemia group (N = 55) according to birth weight and gestational age. Neurodevelopment at 1 month corrected age and brain injury within 1 month corrected age were measured by neonatal behavioral neurological assessments (NBNA) and cranial ultrasound, respectively. Compared to the control group, the early anemia group had a lower score in behavioral ability in the NBNA test [11 (10-12) vs. 10 (9.5-11), p = 0.033]. Early anemia was negatively associated with the NBNA total score (β= -0.680, 95% CI: -1.300, -0.059), especially with the behavioral ability score (β= -0.504, 95% CI: -0.941, -0.067) after adjusting for the confounders. However, no association between early anemia and brain injury was observed. In conclusion, in VLBW preterm infants, early anemia is negatively correlated with neurodevelopment, especially with behavioral ability.

Immunologic effects of red blood cell and platelet transfusions in neonates

PURPOSE OF REVIEW

Premature neonates are frequently transfused red blood cells (RBCs) or platelets to raise hemoglobin or platelet counts. However, these transfusions may have unintended effects on the immune system. This review will summarize the newest discoveries on the immunologic effects of RBC and platelet transfusions in neonates, and their potential impact on neonatal outcomes.

RECENT FINDINGS

Neonatal RBC transfusions are associated with increases in plasma pro-inflammatory cytokines, but recent findings suggest sex-specific differential responses. At least one cytokine (monocyte chemoattractant protein-1) rises in females receiving RBC transfusions, but not in males. These inflammatory responses correlate with poorer neurodevelopmental outcomes in heavily transfused female infants, while preterm male infants seem to be more sensitive to severe anemia. Platelet transfusions in preterm neonates are associated with increased neonatal mortality and morbidity. The underlying mechanisms are unknown, but likely related to the immune/inflammatory effects of transfused platelets. Adult platelets are different from neonatal platelets, with the potential to be more pro-inflammatory. Early preclinical data suggest that platelet transfusions alter the neonatal systemic inflammatory response and enhance immune cell migration.

SUMMARY

RBC and platelet transfusions alter neonatal immune and inflammatory responses. Their pro-inflammatory effects might worsen neonatal disease or affect neurodevelopmental outcomes.

Perioperative Pediatric Erythrocyte Transfusions: Incorporating Hemoglobin Thresholds and Physiologic Parameters in Decision-making

This article presents current literature and scientific evidence on hemoglobin thresholds and physiologic parameters to guide decisions regarding perioperative erythrocyte transfusions in pediatric patients based on the most up-to-date studies and expert consensus recommendations.

Transfusion therapy of neonatal and paediatric patients: They are not just little adults

Patient blood management (PBM) strategies are needed in the neonate and paediatric population, given that haemoglobin thresholds used are often higher than recommended by evidence, with exposure of children to potential complications without meaningful benefit. A literature review was performed on the following topics: evidence-based transfusions of blood components and pharmaceutical agents. Other topics reviewed included perioperative coagulation assessment and perioperative PBM. The Transfusion and Anaemia Expertise Initiative (TAXI) consortium published a consensus statement addressing haemoglobin (Hb) transfusion threshold in multiple subsets of patients. A multicentre trial (PlaNeT-2) reported a higher risk of bleeding and death or serious new bleeding among infants who received platelet transfusion at a higher (50 000/μl) compared to a lower (25 000/μl) threshold. Recent data support the use of a restrictive transfusion threshold of 25 000/μl for prophylactic platelet transfusions in preterm neonates. The TAXI-CAB consortium mentioned that in critically ill paediatric patients undergoing invasive procedures outside of the operating room, platelet transfusion might be considered when the platelet count is less than or equal to 20 000/μl and there is no benefit of platelet transfusion when the platelet count is more than 50 000/μl. There are limited controlled studies in paediatric and neonatal population regarding plasma transfusion. Blood conservation strategies to minimise allogenic blood exposure are essential to positive patient outcomes neonatal and paediatric transfusion practices have changed significantly in recent years since randomised controlled trials were published to guide practice. Additional studies are needed in order to provide practice change recommendations.

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.

Dose- and sex-dependent effects of phlebotomy-induced anemia on the neonatal mouse hippocampal transcriptome

BACKGROUND

Phlebotomy-induced anemia (PIA) is universal and variable in degree among preterm infants and may contribute to neurodevelopmental risk. In mice, PIA causes brain tissue hypoxia, iron deficiency, and long-term sex-dependent neurobehavioral abnormalities. The neuroregulatory molecular pathways disrupted by PIA underlying these effects are unknown.

METHODS

Male and female pups were phlebotomized daily from postnatal day (P)3-P14 via facial venipuncture to target hematocrits of 25% (moderate, mPIA) and 18% (severe, sPIA). P14 hippocampal RNA from non-bled control and PIA mice was sequenced by next-generation sequencing to identify differentially expressed genes (DEGs) that were analyzed using Ingenuity Pathway Analysis.

RESULTS

mPIA females showed the least DEGs (0.5% of &gt;22,000 genes) whereas sPIA females had the most (8.6%), indicating a dose-dependent effect. mPIA and sPIA males showed similar changes in gene expression (5.3% and 4.7%, respectively), indicating a threshold effect at mPIA. The pattern of altered genes induced by PIA indicates sex-specific and anemia-dose-dependent effects with increased pro-inflammation in females and decreased neurodevelopment in males.

CONCLUSION

These gene-expression changes may underlie the reduced recognition memory function in male and abnormal social-cognitive behavior in female adult mice following neonatal PIA. These results parallel clinical studies demonstrating sex-specific behavioral outcomes as a function of neonatal anemia.

IMPACT

Phlebotomy-induced anemia (PIA) in neonatal mice results in an altered hippocampal transcriptome and the severity of changes are dependent upon degree of anemia and sex of neonatal mice. The reported findings provide context to the sex-specific outcomes that have been reported in transfusion threshold clinical trials of preterm infants and therefore may inform treatment strategies that may be based on sex. These data advance the field by showing that consequences of PIA may be based in sex-specific transcriptomic alterations. Such changes may also result from other causes of neonatal anemia that also affect term infants.

Protocol for a Nested, Retrospective Study of the Australian Placental Transfusion Study Cohort

Background

Neonates, particularly if born preterm or with congenital anomalies, are among the pediatric patients most likely to need blood transfusion. However, they are also particularly vulnerable to adverse consequences of blood transfusion. Aiming to clamp the umbilical cord for at least a minute after birth is a simple safe procedure that is being increasingly adopted worldwide, although may be associated with increased rates of polycythemia and jaundice. It may also reduce the proportion of preterm babies who need a blood transfusion. The mechanisms for this are not fully understood. Potential mechanisms could include an increased volume of blood transfusion from the placenta to the baby after birth, and an overall reduction in the severity of illness in the first weeks after birth, which could lead to fewer blood tests and greater tolerance of anemia, or enhanced erythropoiesis.

Objectives

To investigate the mechanism behind the reduced need for blood transfusions after deferral of cord clamping.

Methodology

This protocol outlines the methods and data analysis plan for a study using nested retrospective data from a large randomized trial combined with additional data collected from patient medical and pathology records. The additional data items to be collected all relate to the receipt of transfusion and the factors that affect the risk for transfusion in preterm babies. The analysis will include all randomized babies from Australia and New Zealand for whom data are available. Causal mediation analysis is planned to estimate the effects of mediators on the relationship between the timing of cord clamping and the need for blood transfusion. The analysis is designed to discern whether initial severity of illness or the magnitude of placental transfusion mediates red blood cell transfusion dependence.

Anticipated outcomes and dissemination

We expect the study will identify potential strategies for reducing blood transfusions and associated negative outcomes in preterm infants. This will be relevant to researchers, clinicians, and parents. The results will be disseminated through publications, presentations, and inclusion in evidence-based guidelines.

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.

[Establishment of a nomogram model for predicting necrotizing enterocolitis in very preterm infants]

OBJECTIVES

To investigate the risk factors for necrotizing enterocolitis (NEC) in very preterm infants and establish a nomogram model for predicting the risk of NEC.

METHODS

A total of 752 very preterm infants who were hospitalized from January 2015 to December 2021 were enrolled as subjects, among whom 654 were born in 2015-2020 (development set) and 98 were born in 2021 (validation set). According to the presence or absence of NEC, the development set was divided into two groups: NEC (n=77) and non-NEC (n=577). A multivariate logistic regression analysis was used to investigate the independent risk factors for NEC in very preterm infants. R software was used to plot the nomogram model. The nomogram model was then validated by the data of the validation set. The receiver operating characteristic (ROC) curve, the Hosmer-Lemeshow goodness-of-fit test, and the calibration curve were used to evaluate the performance of the nomogram model, and the clinical decision curve was used to assess the clinical practicability of the model.

RESULTS

The multivariate logistic regression analysis showed that neonatal asphyxia, sepsis, shock, hypoalbuminemia, severe anemia, and formula feeding were independent risk factors for NEC in very preterm infants (P<0.05). The ROC curve of the development set had an area under the curve (AUC) of 0.833 (95%CI: 0.715-0.952), and the ROC curve of the validation set had an AUC of 0.826 (95%CI: 0.797-0.862), suggesting that the nomogram model had a good discriminatory ability. The calibration curve analysis and the Hosmer-Lemeshow goodness-of-fit test showed good accuracy and consistency between the predicted value of the model and the actual value.

CONCLUSIONS

Neonatal asphyxia, sepsis, shock, hypoalbuminemia, severe anemia, and formula feeding are independent risk factors for NEC in very preterm infant. The nomogram model based on the multivariate logistic regression analysis provides a quantitative, simple, and intuitive tool for early assessment of the development of NEC in very preterm infants in clinical practice.

Recommendations for transfusion of blood products in neonatology

The scant evidence on the use of transfusions in neonatal care explains the limitations of current clinical guidelines. Despite this, in this document we explore the most recent evidence to make recommendations for the clinical practice. The prevention of anaemia of prematurity, the use of protocols and restrictive transfusion strategies constitute the best approach for clinicians in this field. In the case of platelet transfusions, the risk of bleeding must be assessed, combining clinical and laboratory features. Lastly, fresh frozen plasma is recommended in neonates with coagulopathy and active bleeding, with congenital factor deficiencies for which there is no specific treatment or with disseminated intravascular coagulation. All blood products have adverse effects that warrant a personalised and thorough assessment of the need for transfusion.

Effects of Freshly Irradiated vs Irradiated and Stored Red Blood Cell Transfusion on Cerebral Oxygenation in Preterm Infants: A Randomized Clinical Trial

IMPORTANCE

Gamma irradiation of leukoreduced red blood cells (RBCs) prevents transfusion-associated graft-vs-host disease but also exacerbates storage lesion formation in RBCs. It is unknown whether freshly irradiated RBCs are more efficacious than irradiated and stored RBCs in preterm infants with high transfusion requirements.

OBJECTIVE

To examine whether transfusion of freshly irradiated vs irradiated and stored RBC components improves cerebral oxygen delivery in preterm infants with anemia.

DESIGN, SETTING, AND PARTICIPANTS

This single-center, double-blinded, proof-of-concept randomized clinical trial was conducted at the neonatal intensive care unit of Wellington Regional Hospital in Wellington, New Zealand, between December 1, 2017, and November 30, 2018. Participants were preterm infants (<34 weeks' gestation at birth) who were at least 14 days of age and had anemia. Participants underwent nonurgent transfusions, and these episodes were randomized to the intervention group (in which the infants received a transfusion of RBCs that were freshly irradiated on the day of transfusion) or control group (in which the infants received a transfusion of RBCs that were irradiated and stored for up to 14 days). Data were analyzed using the evaluable population approach.

INTERVENTION

Transfusion of freshly irradiated RBCs.

MAIN OUTCOMES AND MEASURES

The prespecified primary outcome was the change in cerebral regional oxygen saturation (crSO2) from baseline (immediately before) to immediately after the transfusion. The prespecified secondary outcomes were the change in cerebral fractional tissue oxygen extraction (cFTOE) at different time points (immediately after, 24 hours after, and 120 hours or 5 days after transfusion). Outcomes were measured by blinded clinicians using near-infrared spectroscopy. A covariate-adjusted linear mixed model was used to quantify mean treatment effects and account for multiple transfusions in some infants.

RESULTS

A total of 42 infants (mean [SD] gestational age, 26 [10] weeks and 3 days; 29 [69%] boys) were enrolled in the trial and underwent 64 transfusion episodes, which were randomized to the intervention (n = 31) or control (n = 33) group. Compared with infants in the control group, those in the intervention group showed a covariate-adjusted mean increase in crSO2 (2.0 percentage points; 95% CI, 1.2-2.8 percentage points) and a mean decrease in cFTOE (0.02; 95% CI, 0.01-0.04) immediately after transfusion. These differences were sustained up to 120 hours or 5 days after transfusion. There were negligible mean changes in crSO2 or cFTOE in infants in the control group at any of the follow-up time points.

CONCLUSIONS AND RELEVANCE

Results of this trial showed that transfusion of freshly irradiated RBCs conferred a small advantage in cerebral oxygenation for at least 5 days after transfusion compared with transfusion of irradiated and stored RBC components. On-demand irradiation of RBC components may be considered to optimize oxygen delivery in the recipient, but this physiological finding requires further research.

TRIAL REGISTRATION

ANZCTR Identifier: ACTRN12617001581358.

Sex Differences in the Association of Pretransfusion Hemoglobin Levels with Brain Structure and Function in the Preterm Infant

OBJECTIVE

To assess sex-specific differences in early brain structure and function of preterm infants after red blood cell (RBC) transfusions.

STUDY DESIGN

A single-center subset of infants with a birth weight <1000 g and gestational age 22-29 weeks were enrolled from the National Institute of Child Health and Human Development's Neonatal Research Network Transfusion of Prematures Trial. Hemoglobin (Hb) concentration obtained directly before each transfusion (pretransfusion Hb [ptHb]) was obtained longitudinally throughout each infant's neonatal intensive care unit stay and used as a marker of degree of anemia (n = 97). Measures of regional brain volumes using magnetic resonance imaging were obtained at ∼40 weeks postmenstrual age or at hospital discharge, if earlier (n = 29). Measures of brain function were obtained at 12 months corrected age using the Bayley Scales of Infant & Toddler Development, 3rd Edition (n = 34).

RESULTS

PtHb was positively correlated with neonatal cerebral white matter volume in males (B = +0.283; P = .006), but not females (B = -0.099; P = .713), resulting in a significant sex interaction (P = .010). Bayley-III gross motor scores and a pooled mean score were significantly lower in association with higher ptHb in females (gross motor score: B = -3.758; P = .013; pooled mean score: B = -1.225; P = .030), but not males (gross motor score: B = +1.758; P = .167; pooled mean score: B = +0.621; P = .359). Higher ptHb was associated with descriptively lower performance on multiple Bayley-III subscales in females, but not in males.

CONCLUSIONS

This study demonstrates sex-specific associations between an early marker of anemia and RBC transfusion status (ie, ptHb) with both neonatal white matter volume and early cognitive function at age 12 months in preterm infants.

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.

Red cell transfusion thresholds for preterm infants: finally some answers

Extremely low birthweight infants become anaemic during their care in the neonatal intensive care unit because of the physiological anaemia experienced by all newborn infants compounded by early umbilical cord clamping, blood loss by phlebotomy for laboratory monitoring and delayed erythropoiesis. The majority of these infants receive transfusions of packed red blood cells, usually based on haemoglobin values below a certain threshold. The haemoglobin or haematocrit thresholds used to guide transfusion practices vary with infant status and among institutions and practitioners. Previous smaller studies have not given clear guidance with respect to the haemoglobin thresholds that should trigger transfusions or even if this is the best way to decide when to transfuse an infant. Two large clinical trials of similar design comparing higher and lower haemoglobin thresholds for transfusing extremely low birthweight infants were recently published, the ETTNO and TOP trials. These trials found reassuringly conclusive and concordant results. Within the range of haemoglobin transfusion thresholds studied, there was no difference in the primary outcome (which was the same in both studies), neurodevelopmental impairment at 2 years' corrected age or death before assessment, in either study. In addition, there was no difference in either study in either of the components of the primary outcome. In conclusion, haemoglobin transfusion thresholds within the ranges used in these trials, 11-13 g/dL for young critically ill or ventilated infants and 7-10 g/dL for stable infants not requiring significant respiratory support, can be safely used without expecting adverse consequences on survival or neurodevelopment.

Comparison of Hematocrit Change in Preterm Neonates with Birth Weight Based Versus Formula Based Packed Red Blood Cell Transfusion: A Randomized Control Trial

Conventionally the packed red blood cell (PRBC) transfusion volume given to neonates is 10 ml/kg to 20 ml/kg. The weight-based formulae underestimate the volume of PRBC required to achieve a target hematocrit (Hct) in preterm neonates. The study was done to compare the rise in Hct after transfusing PRBC volume calculated either based on body weight or using formula considering Hct of blood bag and Hct of preterm neonates. This prospective study included a total of 68 preterm neonates requiring transfusion for the first time having ≤ 34 weeks of gestational age. Neonates were randomized using block randomization, to receive 15 ml/kg of PRBC transfusion (group A) or transfusion based on the formula (group B). The primary outcome of interest was post-transfusion rise in hematocrit. The secondary outcome was the effect of transfusion on neonatal morbidities in terms of retinopathy of prematurity, bronchopulmonary dysplasia, intraventricular hemorrhage, necrotizing enterocolitis, and death. Baseline variables (birth weight, gestation age, APGAR score and score of neonatal acute physiology) pre-transfusion hemodynamics and hematocrit of the bag were comparable in both groups. The mean volume of PRBC in group A was 18.8 ± 4.9 ml, whereas in group B it was 29.6 ± 7.3 ml, p = 0.0001. Group B transfusions had a statistically significant change in 24 h post-transfusion hematocrit. Secondary outcomes were comparable in two groups. Post transfusion rise in Hct of the patient in group B was significant as compared to group A. The study needed huge sample size to establish a difference in the number of re-transfusions required across two groups. The trial was registered under the clinical trial registry of India (CTRI/2018/01/011,063).

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s12288-021-01420-1.