Temporal changes in blood product usage in preterm neonates born at less than 30 weeks' gestation in Canada

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.

Measurement of lead, mercury, and cadmium in blood donors in Canada

BACKGROUND

Fetal and neonatal exposure to lead is associated with irreversible adverse effects on neural development. There is no reliable threshold for lead effect, so limiting exposure is recommended. A significant correlation has been reported between post-transfusion blood lead level (BLL) in infants and lead levels in transfused RBC units. We measured levels of lead, mercury, and cadmium, in Canadian donor blood to investigate if concerning levels for neonatal transfusion exist.

STUDY DESIGN AND METHODS

Whole blood samples from blood donors (n = 2529) were shipped cold within 7 days of donation. All permanent blood donation clinics across Canada were sampled. Twelve of these permanent clinics and 8 mobile clinics with a greater potential for having higher lead or mercury levels were oversampled. Heavy metals were measured by inductively coupled plasma mass spectrometry.

RESULTS

Of all donations, 2.2% (lead) and 0.4% (mercury) had levels higher than the recommended thresholds for safe neonatal transfusion. BLLs were higher in males but there was no significant difference in the blood mercury levels of males versus females. Cadmium levels were higher in females. There was a positive correlation between donor age and levels of heavy metals, with lead having the strongest correlation (r = 0.47, p < .0001). Three clinics in close proximity to two lead-producing mines were among the clinics with the highest BLLs. Significantly higher blood mercury levels were observed in coastal clinics.

CONCLUSION

Our data on donor blood heavy metal levels supports considering blood transfusion as an exposure source to heavy metals and encourages informed selection of blood units for transfusion to vulnerable groups.

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.

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..

Development and validation of a novel risk classification tool for predicting long length of stay in NICU blood transfusion infants

Newborns are as the primary recipients of blood transfusions. There is a possibility of an association between blood transfusion and unfavorable outcomes. Such complications not only imperil the lives of newborns but also cause long hospitalization. Our objective is to explore the predictor variables that may lead to extended hospital stays in neonatal intensive care unit (NICU) patients who have undergone blood transfusions and develop a predictive nomogram. A retrospective review of 539 neonates who underwent blood transfusion was conducted using median and interquartile ranges to describe their length of stay (LOS). Neonates with LOS above the 75th percentile (P75) were categorized as having a long LOS. The Least Absolute Shrinkage and Selection Operator (LASSO) regression method was employed to screen variables and construct a risk model for long LOS. A multiple logistic regression prediction model was then constructed using the selected variables from the LASSO regression model. The significance of the prediction model was evaluated by calculating the area under the ROC curve (AUC) and assessing the confidence interval around the AUC. The calibration curve is used to further validate the model's calibration and predictability. The model's clinical effectiveness was assessed through decision curve analysis. To evaluate the generalizability of the model, fivefold cross-validation was employed. Internal validation of the models was performed using bootstrap validation. Among the 539 infants who received blood transfusions, 398 infants (P75) had a length of stay (LOS) within the normal range of 34 days, according to the interquartile range. However, 141 infants (P75) experienced long LOS beyond the normal range. The predictive model included six variables: gestational age (GA) (< 28 weeks), birth weight (BW) (< 1000 g), type of respiratory support, umbilical venous catheter (UVC), sepsis, and resuscitation frequency. The area under the receiver operating characteristic (ROC) curve (AUC) for the training set was 0.851 (95% CI 0.805-0.891), and for the validation set, it was 0.859 (95% CI 0.789-0.920). Fivefold cross-validation indicates that the model has good generalization ability. The calibration curve demonstrated a strong correlation between the predicted risk and the observed actual risk, indicating good consistency. When the intervention threshold was set at 2%, the decision curve analysis indicated that the model had greater clinical utility. The results of our study have led to the development of a novel nomogram that can assist clinicians in predicting the probability of long hospitalization in blood transfused infants with reasonable accuracy. Our findings indicate that GA (< 28 weeks), BW(< 1000 g), type of respiratory support, UVC, sepsis, and resuscitation frequency are associated with a higher likelihood of extended hospital stays among newborns who have received blood transfusions.

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.

A Systematic Review: Is Early Fluid Restriction in Preterm Neonates Going to Prevent Bronchopulmonary Dysplasia?

Preterm birth causes constant challenges, with bronchopulmonary dysplasia (BPD) being a major concern. Immediately after birth, it takes time to establish feeding between the mother and the premature baby. During this time, the telological shifting of fluid from extracellular space to intracellular space will help the baby; this transition should be smooth. Both normal physiologic changes and pathophysiologic events are capable of disrupting this delicate fluid shifting that occurs in very low-birth-weight infants during the first week of life. The immaturity of the renal system and evaporative losses complicate this process. This lack of fluid displacement can be associated with an increased amount of water in the lungs and reduced lung compliance. This can lead to the need for more ventilatory support and a higher oxygen requirement, which, in turn, leads to lung damage. The fluid restriction is also associated with complications such as severe dehydration, intracranial hemorrhage, and bilirubin toxicity. However, the administration of large amounts of fluid and salt is associated with an increased incidence of patent ductus arteriosus, BPD, necrotizing enterocolitis, and intraventricular hemorrhage. There were studies conducted in both the pre-surfactant and surfactant eras that were inconclusive regarding fluid restriction in BPD. We only included very recent studies. This systematic review attempts to summarize the current evidence, focusing on the efficacy and safety of early fluid management in preterm infants. This reduces the risk of BPD and improves outcomes for premature infants. As we know, intact survival is very important. Our review supported the early fluid restriction.

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.

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.

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.

Mortality and Comorbidities in Extremely Low Birth Weight Thai Infants: A Nationwide Data Analysis

This is the first nationwide study aimed to evaluate in-hospital mortality and comorbidities of extremely low birth weight (ELBW) infants in Thailand between 2015-2020. Data of ELBW infants were collected from the National Health Coverage Scheme. The incidence of ELBW Thai infants was 1.75 per 1000 live births. Sixty-five percent of ELBW infants were delivered in tertiary-care facilities, with 63% surviving until discharge. In-hospital mortality was 36.9%. Non-invasive respiratory supports were documented in just 17.6% of the study population, whereas total parenteral nutrition was used in 52.3% of neonates. There were several comorbidities, with the three most frequent including respiratory distress syndrome (70.7%), neonatal jaundice (66.7%), and sepsis (60.4%). The median hospitalization cost for one ELBW infant who survived was 296,438.40 baht ($8719). Conclusion: Thailand had an acceptable ELBW infant survival rate (63%), but comorbidities remained particularly severe and cost one hundred times the median hospital cost for one ELBW infant that survived in comparison to a normal newborn infant. Better health outcomes require strategies to raise awareness of the issues and the appropriate implementation of evidence-based solutions, particularly improving neonatal care facilities, as well as early referral of high-risk pregnant women and neonates, which will aid in the future reduction of neonatal morbidities and mortalities.

Preterm infant circulating sex steroid levels are not altered by transfusion with adult male plasma: a retrospective multicentre cohort study

OBJECTIVE

To determine if plasma transfusions with male donor plasma to very preterm infants affect circulatory levels of sex steroids.

DESIGN AND PATIENTS

Retrospective multicentre cohort study in 19 infants born at gestational age <29 weeks requiring plasma transfusion during their first week of life.

SETTING

Three neonatal intensive care units in Sweden.

MAIN OUTCOME MEASURES

Concentrations of sex steroids and sex hormone-binding globulin (SHBG) in donor plasma and infant plasma measured before and after a plasma transfusion and at 6, 12, 24 and 72 hours.

RESULTS

The concentrations of progesterone, dehydroepiandrosterone and androstenedione were significantly lower in donor plasma than in infant plasma before the transfusion (median (Q1-Q3) 37.0 (37.0-37.0), 1918 (1325-2408) and 424 (303-534) vs 901 (599-1774), 4119 (2801-14 645) and 842 (443-1684) pg/mL), while oestrone and oestradiol were higher in donor plasma (17.4 (10.4-20.1) and 16.0 (11.7-17.2) vs 3.1 (1.1-10.2) and 0.25 (0.25-0.25) pg/mL). Median testosterone and dihydrotestosterone (DHT) levels were 116-fold and 21-fold higher in donor plasma than pre-transfusion levels in female infants, whereas the corresponding difference was not present in male infants. Plasma sex steroid levels were unchanged after completed transfusion compared with pre-transfusion levels, irrespective of the gender of the receiving infant. The SHBG concentration was significantly higher in donor than in recipient plasma (22.8 (17.1-33.5) vs 10.2 (9.1-12.3) nmol/L) before transfusion but did not change in the infants after the transfusion.

CONCLUSIONS

A single transfusion of adult male plasma to preterm infants had no impact on circulating sex steroid levels.

Red blood cell transfusions post diagnosis of necrotizing enterocolitis and the deterioration of necrotizing enterocolitis in full-term and near-term infants: a propensity score adjustment retrospective cohort study

Background

Necrotizing enterocolitis (NEC) is one of serious gastrointestinal inflammatory diseases in newborn infants, with a high morbidity and mortality. Red blood cell transfusion (RBCT) plays a controversial and doubtful role in the treatment of NEC. In present study, we aim to analyze the association between RBCT and the deterioration of NEC.

Methods

This was a retrospective cohort study of near-term and full-term infants with a confirmed diagnosis of Bell’s stage II NEC between Jan 1, 2010 and Jan 31, 2020. The maternal and infant baseline characteristics, treatment information and laboratory test for each case were collected. The eligible subjects were divided into two groups based on receiving RBCT post NEC diagnosis or not. The propensity score was used to eliminate potential bias and baseline differences. A multivariate logistic regression model was used to adjust the propensity score and calculate the odds ratio (OR) and 95% confidential interval (CI) of RBCT for the deterioration of NEC.

Results

A total of 242 infants were included in this study, 60 infants had a history of RBCT post NEC diagnosis, and 40 infants deteriorated from Bell’s stage II to stage III. By adjusting the propensity score, RBCT post NEC diagnosis was associated with an increased risk for NEC deteriorating from stage II to III (adjusted OR 6.06, 95%CI 2.94–12.50, P = 0.000).

Conclusions

NEC infants who required RBCT post NEC diagnosis were more likely to deteriorate from stage II to III in full-term and near-term infants.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03276-4.

Neonatal and pediatric transfusion practices and policies in India: A survey-based cross-sectional assessment of blood centers

BACKGROUND

Blood centers play a critical role in supporting neonatal and pediatric transfusions. We aim to study the variation in pediatric/neonatal transfusion policies and practices for blood centers in India.

STUDY DESIGN AND METHODS

This is a survey-based (45 question) cross-sectional assessment of blood centers in India supporting pediatric/neonatal transfusions.

RESULTS

One hundred three centers responded to the survey (response rate 51.2%; 103/201). As a part of pretransfusion testing, use of "microtainers" was reported by 58.4% (59/101) centers and only 57.4% (58/101) centers provide antibody screening. In case of absence of maternal sample, type O negative blood is most commonly used (48.5%; 49/101), and in case of ABO incompatibility, 68.3% (69/101) use units compatible with both mother and newborn. Leukoreduced RBCs are provided by 89% (90/101) centers and irradiated products are provided by 48.5% (49/101). 82% (83/101) of centers reported not receiving requests for CMV negative units considering the high incidence of CMV-seropositivity in donors. Fresh units are defined as <7 days old by 44.5% (45/101) and <5 days old by 31.6% (32/101) centers. 97% centers reported SAGM suspended RBCs in inventory but only 67.3% (68/101) use them for top-up transfusions to neonates. Overall >80% centers use the buffy-coat method for platelet concentrates preparation. Volume-based (ml/kg) aliquots preparation is done by 88% (89/101), mainly using the sterile connecting device (84.6%; 83/98).

CONCLUSION

This survey shows heterogeneity and lack of standardization in practices across blood centers in India and highlights the need for more studies to establish best practices for this vulnerable age group.

Patterns and Determinants of Blood and Blood Products Transfusion in Neonate: An Experience of Single Institute

BACKGROUND: Neonates requiring intensive care are among the most frequently transfused group of patients. Indications for blood transfusion in neonates could be physiological or pathological. However, despite frequent blood transfusions in neonates in Iraq, there is a paucity of studies on its indications and patterns among neonates in our setting. AIM: The aim of the study is to shed light on the details of giving blood and blood products in the unit of neonate in Children Welfare Teaching hospital, Baghdad and the justifications for giving and its complication. PATIENTS AND METHODS: A descriptive study (cross-section study) includes all neonates admitted to neonatal care unit in Children Welfare Teaching Hospital. The study includes a group of newborns who were blood transfused during their admission to hospital, over a period of 6 months from October 1, 2019 to March 30, 2020. All data were collected from each patient and recorded in predesigned forma, these data include patient’s clinical data and analyzed using descriptive statistics. RESULTS: A total number of cases admitted over a period of 6 months were 862. One hundred and forty neonates received blood and its products transfusion, (61.4%) were male and (38.6%) were female, (62.9%) received packed red blood cells (PRBCs) followed by (18.6%) received exchange transfusion, (11.4%) received Fresh frozen plasma and (7.1%) received platelets. Most neonates received blood products transfused at (3–4) weeks. Post-natal age and were term babies (37–41) weeks. Gestational age mostly received PRBCs. CONCLUSIONS: Most neonates with a high rate of blood and blood product transfusion were males, term, need assistant ventilation, and transfused at 3–4 weeks postnatal age.

Sex-specific cytokine responses and neurocognitive outcome after blood transfusions in preterm infants

BACKGROUND

The objective of this study was to determine sex-specific differences in inflammatory cytokine responses to red blood cell (RBC) transfusion in preterm infants in the neonatal period and their relationship to later neurocognitive status.

METHODS

Infants with a birth weight <1000 g and gestational age 22-29 weeks were enrolled in the Transfusion of Prematures (TOP) trial. The total number of transfusions was used as a marker of transfusion status. Nineteen cytokines and biomarkers were analyzed from 71 infants longitudinally during the neonatal period. Twenty-six infants completed the Bayley Scales of Infant & Toddler Development, 3rd Edition (Bayley-III) at 12 months' corrected age.

RESULTS

Nine cytokine levels were significantly elevated in proportion to the number of transfusions received. Of those, one cytokine showed a sex-specific finding (p = 0.004): monocyte chemoattractant protein-1, MCP-1, rose substantially in females (8.9% change per additional transfusion), but not in males (-0.8% change). Higher concentrations of MCP-1 exclusively were associated with worse Bayley-III scores: decreased cognitive raw scores (p = 0.0005) and motor scaled scores (p < 0.0001).

CONCLUSIONS

This study provides evidence of a sex-specific difference in the inflammatory response to RBC transfusions during neonatal life, with MCP-1 levels rising only in females and inversely correlating with neurocognitive status at 12 months old.

IMPACT

It is important to understand the risk factors for abnormal neurodevelopment in preterm infants, including anemia and RBC transfusion, in order to improve outcomes and provide potential targets for therapy. Our study investigates and provides the first evidence of sex-specific differences in inflammatory cytokine responses to RBC transfusions in preterm infants in the neonatal period, and their relationship to later cognitive outcomes. This study critically suggests that different transfusion thresholds may have a sex-specific effect on neurodevelopment: females have worse cognitive outcomes with increased number of transfusions, while males have worse outcomes with lower number of transfusions.

Neonatal anemia relates to intestinal injury in preterm infants

BACKGROUND

Anemia is associated with decreased tissue oxygenation in preterm infants and may contribute to developing necrotizing enterocolitis (NEC). We aimed to investigate whether hemoglobin level is associated with intestinal injury, by comparing anemic infants 10 days prior to red blood cell (RBC) transfusion with non-anemic controls.

METHODS

A nested case-control study in which we matched anemic preterms (gestational age (GA) < 32 weeks) with non-anemic controls (1:1), based on GA, birth weight (BW), and postnatal age. We measured urinary intestinal fatty acid-binding protein, I-FABP, marker for intestinal injury, twice weekly. Simultaneously, we assessed splanchnic oxygen saturation (r_sSO₂) and r_sSO₂ variability.

RESULTS

Thirty-six cases and 36 controls were included (median GA 27.6 weeks, BW 1020 grams). Median I-FABP level was higher in cases from 6 days to 24-h before transfusion (median ranging: 4749-8064 pg/ml versus 2194-3751 pg/ml). R_sSO₂ and r_sSO₂ variability were lower in cases than controls shortly before transfusion. Hemoglobin levels correlated negatively with r_sSO₂ and r_sSO₂ variability in cases, and negatively with I-FABP in cases and controls together.

CONCLUSIONS

Urinary I-FABP levels were higher in anemic infants before RBC transfusion than in non-anemic matched controls, suggesting intestinal injury associated with anemia. This may predispose to NEC in some anemic preterm infants.

IMPACT

Anemia is a common comorbidity in preterm infants and may lead to impaired splanchnic oxygen saturation and intestinal tissue hypoxia, a proposed mechanism for NEC. Lower hemoglobin level is associated with higher urinary I-FABP levels, a marker for intestinal injury, both in anemic preterm infants and in cases and controls together. Lower splanchnic oxygen saturation and reduction of its variability are associated with higher urinary I-FABP levels in anemic preterm infants before their first RBC transfusion. These results support the hypothesis that anemia in very preterm infants results in intestinal cell injury, which may precede NEC development in some.

Cardiorespiratory monitoring of red blood cell transfusions in preterm infants

Clinical improvement after red blood cell (RBC) transfusions in preterm infants remains debated. This study aims to investigate the effect of RBC transfusion on the occurrence of desaturations and hypoxia, and other cardiorespiratory outcomes in preterm infants. In this longitudinal observational study, prospectively stored cardiorespiratory parameters of preterm infants who received at least one RBC transfusion between July 2016 and June 2017 were retrospectively analyzed. Sixty infants with 112 RBC transfusions, median GA of 26.7 weeks, were included. The number of desaturations and area < 80% SpO₂ limit, as a measure of the hypoxic burden, were calculated in 24 h before and after RBC transfusion. A mixed effects model was used to account for repeated measurements. Overall, the mean (SE) number of desaturations per hour decreased from 3.28 (0.55) to 2.25 (0.38; p < 0.001), and area < 80% SpO₂ limit decreased from 0.14 (0.04) to 0.08 (0.02) %/s (p = 0.02). These outcomes were stratified for the number of desaturations in 24 h prior to RBC transfusion. The largest effect was observed in the group with the highest mean number of desaturations (≥ 6) prior to RBC transfusion, with a decrease from 7.50 (0.66) to 4.26 (0.38) (p < 0.001) in the number of desaturations and 0.46 (0.13) to 0.20 (0.06) in the area < 80% SpO₂. Perfusion index increased significantly after RBC transfusion (p < 0.001). No other significant effects of RBC transfusion on cardiorespiratory data were observed.Conclusions: RBC transfusions in preterm newborns could help decrease the incidence of desaturations and the area < 80% SpO₂ as a measure of the hypoxic burden. The higher the number of desaturations prior to the RBC transfusion, the larger the effect observed. What is Known: •Red blood cell transfusions potentially prevent hypoxia in anemic preterm infants by increasing the circulatory hemoglobin concentration and improving tissue oxygenation. •There is not a predefined hemoglobin concentration cut-off for the occurrence of symptomatic anemia in preterm infants. What is New: •Oxygen desaturations and hypoxia in anemic preterm infants can be improved by RBC transfusions, especially if more desaturations have occurred before transfusion. •Cardiorespiratory monitor data may help identify infants who will benefit most from red blood cell transfusions.

Assessment of synthetic red cell therapy for extremely preterm ovine fetuses maintained on an artificial placenta life-support platform

BACKGROUND

Artificial placenta therapy (APT) is an experimental care strategy for extremely preterm infants born at 21-24 weeks' gestation. In our previous studies, blood taken from the maternal ewe was used as the basis of priming solutions for the artificial placenta circuit. However, the use of maternal blood as a priming solution is accompanied by several challenges. We explored the use of synthetic red cells (hemoglobin vesicles; HbV) as the basis of a priming solution for APT used to manage extremely early preterm ovine fetuses.

METHODS

Six ewes with singleton pregnancies at 95 d gestation (term = 150 d) were adapted to APT and maintained with constant monitoring of key vital parameters. The target maintenance period was 72 h in duration. A synthetic red cell solution consisting of HbV, sheep albumin and electrolytes was used as priming solutions for the APT circuit. Fetuses were evaluated on gross appearance, physiological parameters and bleeding after euthanasia.

RESULTS

Two out of six APT fetuses were successfully maintained for the targeted 72 h experimental period with controllable anemia (>10 g/dl) and methemoglobinemia (<10%) using an infusion of blood transfusion and nitroglycerin delivered >1 h after APT commencement, a sufficient period of time to cross-match blood products and screen for viral agents of concern.

CONCLUSIONS

Extremely preterm sheep fetuses were maintained for a period of up to 72 h using APT in combination with circuit priming using a synthetic red cell (HbV) preparation. Although significant further refinements are required, these findings demonstrated the potential clinical utility of synthetic blood products in the eventual clinical translation of artificial placenta technology to support extremely preterm infants.

Effects of blood sampling stewardship and erythropoietin administration in extremely low birth weight infants-a quality improvement non-controlled before-and-after retrospective study

The majority of extremely low birth weight (ELBW) neonates receive red blood cell (RBC) transfusions; at least 50% receive multiple transfusions. Anemia care bundles could be the most effective approach to reduce transfusion rates. We conducted a quality improvement non-controlled before-and-after retrospective study involving 345 ELBW infants admitted over a 5-year period in two consecutive epochs before and after implementation of an anemia care bundle in January 2017. Bundle components included (a) prophylactic subcutaneous erythropoietin twice each week (600 IU/kg/week) from day 7 through 8 weeks of age and (b) blood sampling stewardship in the first five postnatal weeks. Early postnatal blood sampling losses were significantly reduced following the implementation of the care bundle (21.2 ml/kg vs 25 ml/kg, P < 0.001). We found a 50% reduction in the rate of multiple RBC transfusions (adjusted RR 0.45, 95% CI: 0.34-0.59) and a reduced odds of necrotizing enterocolitis (NEC) (4% vs 10%, adjusted OR 0.38 (95% CI: 0.15-0.78)) among infants that received the anemia care bundle (n = 182 infants). The overall transfusion rate, number and volume of transfusions, and multiple donor exposures were also significantly reduced.Conclusion: The combination of extended subcutaneous erythropoietin administration and reduced early postnatal blood sampling was associated with a significant reduction in the rate of multiple erythrocyte transfusions and NEC in ELBW neonates. What is known: • The majority of extremely low birth weight neonates continue to require blood transfusions despite advances in standardized transfusion practices; at least 50% require multiple transfusions. • Anemia care bundles, employing a combination of anemia prevention strategies, can effectively reduce the RBC transfusion rates in ELBW infants. What is new: • A combination of extended subcutaneous erythropoietin supplementation and blood sampling stewardship practices reduced the rate of multiple RBC transfusions in ELBW neonates by 50%. • Implementation of the anemia care bundle was associated with a significant reduction in the rates of necrotizing enterocolitis.

Closing the evidence to practice gap in neonatal transfusion medicine

Significant resources are directed towards world-class research projects, but the findings are not necessarily translated into better healthcare outcomes, either at all or in a sustained way. There is a clear need to dedicate further resources to understanding how to promote the uptake of evidence and effectively change neonatal transfusion practice to improve outcomes. Approaching blood transfusion behaviour change more systematically, and working across disciplines and involving families, holds the potential to increase the rate of uptake of emerging evidence in clinical practice. This approach holds the potential to save costs, conserve resources, and improve clinical outcomes. Our paper focuses on the use of quality improvement to bridge the gap between evidence-based knowledge and transfusion practice in neonatal units around the world.

Higher or Lower Hemoglobin Transfusion Thresholds for Preterm Infants

BACKGROUND

Limited data suggest that higher hemoglobin thresholds for red-cell transfusions may reduce the risk of cognitive delay among extremely-low-birth-weight infants with anemia.

METHODS

We performed an open, multicenter trial in which infants with a birth weight of 1000 g or less and a gestational age between 22 weeks 0 days and 28 weeks 6 days were randomly assigned within 48 hours after delivery to receive red-cell transfusions at higher or lower hemoglobin thresholds until 36 weeks of postmenstrual age or discharge, whichever occurred first. The primary outcome was a composite of death or neurodevelopmental impairment (cognitive delay, cerebral palsy, or hearing or vision loss) at 22 to 26 months of age, corrected for prematurity.

RESULTS

A total of 1824 infants (mean birth weight, 756 g; mean gestational age, 25.9 weeks) underwent randomization. There was a between-group difference of 1.9 g per deciliter (19 g per liter) in the pretransfusion mean hemoglobin levels throughout the treatment period. Primary outcome data were available for 1692 infants (92.8%). Of 845 infants in the higher-threshold group, 423 (50.1%) died or survived with neurodevelopmental impairment, as compared with 422 of 847 infants (49.8%) in the lower-threshold group (relative risk adjusted for birth-weight stratum and center, 1.00; 95% confidence interval [CI], 0.92 to 1.10; P = 0.93). At 2 years, the higher- and lower-threshold groups had similar incidences of death (16.2% and 15.0%, respectively) and neurodevelopmental impairment (39.6% and 40.3%, respectively). At discharge from the hospital, the incidences of survival without severe complications were 28.5% and 30.9%, respectively. Serious adverse events occurred in 22.7% and 21.7%, respectively.

CONCLUSIONS

In extremely-low-birth-weight infants, a higher hemoglobin threshold for red-cell transfusion did not improve survival without neurodevelopmental impairment at 22 to 26 months of age, corrected for prematurity. (Funded by the National Heart, Lung, and Blood Institute and others; TOP ClinicalTrials.gov number, NCT01702805.).

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.

Changes in the Use of Fresh-Frozen Plasma Transfusions in Preterm Neonates: A Single Center Experience

The aim of this study was to evaluate changes in the use of fresh-frozen plasma (FFP) transfusions and the use of clotting tests in preterm neonates in our center over the past two decades. In this retrospective cohort analysis, we included all consecutive neonates with a gestational age at birth between 24 + 0 and 31 + 6 weeks admitted to our neonatal intensive care unit (NICU) between 2004 and 2019. We divided all included neonates into three consecutive time epochs according to date of birth: January 2004 to April 2009, May 2009 to August 2014 and September 2014 to December 2019. The main outcomes were the use of FFP transfusion, coagulation testing and the indications for FFP transfusion. The percentage of preterm neonates receiving FFP transfusion decreased from 5.7% (47/824) to 3.7% (30/901) to 2.0% (17/852) from the first epoch to the last epoch (p < 0.001). Additionally, the rate of neonates undergoing coagulation testing decreased from 24.3% (200/824) to 14.5% (131/901) to 8% (68/852) over the epochs (p < 0.001). Most FFP transfusions were prescribed prophylactically based on prolongation of activated partial thromboplastin time (aPTT) or prothrombin time (PT) (56%). In conclusion, both the use of FFP transfusions and the use of coagulation tests decreased significantly over the years. The majority of the FFP transfusions were administrated prophylactically for abnormal coagulation tests.

Neonatal and pediatric platelet transfusions: current concepts and controversies

PURPOSE OF REVIEW

In this review, we focus on three specific concepts related to platelet transfusion in the neonatal and pediatric population: choice of transfusion threshold; use of ABO-mismatched platelets; transfusion of pathogen-reduced or inactivated platelets.

RECENT FINDINGS

Recent trials support the use of lower platelet transfusion thresholds (25 000/μl) in preterm neonates, although data is limited to guide transfusion among more mature neonates. In children, there is low-level evidence as to what the prophylactic platelet transfusion threshold should be in many situations of thrombocytopenia, revealing major variability in platelet transfusion practices. Most pediatric guidelines are extrapolated from adult studies with the most evidence in treatment-associated hypoproliferative thrombocytopenia varying between a platelet transfusion threshold of 10 000/μl to 20 000/μl. Although pathogen-reduced platelets may lower the risks of transfusion-transmitted infection, the effects on platelet refractoriness and transfusion burden in this population warrant additional study.

SUMMARY

Our review highlights recent advances in neonatal and pediatric platelet transfusion and also emphasizes the urgent need for better evidence to guide practice given recent studies showing the potential harms of platelet transfusion, particularly with liberal use.

Transfusion-related Gut Injury and Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) accounts for 10% of deaths in neonatal intensive care units. Several causal mechanisms are likely to lead to a final common disease phenotype. This article summarizes recent data on NEC following red blood cell (RBC) transfusion, with a focus on the most recent literature and ongoing trials. It highlights potential mechanisms from preclinical and human physiologic studies. It also discusses the role of feeding during RBC transfusion and the risk of NEC. Ongoing randomized trials will provide important data on how liberal or conservative approaches to RBC transfusion influence the risk of NEC.

Perioperative Transfusions and Venous Thromboembolism

BACKGROUND AND OBJECTIVES

Annual incidence of venous thromboembolism (VTE) including postoperative VTE in hospitalized children is rising significantly. A growing body of evidence supports the role of red blood cells (RBCs) in pathologic thrombosis. In this study, we examined the association of perioperative RBC transfusion with postoperative VTE in pediatric patients.

METHODS

The pediatric databases of the American College of Surgeons' National Surgical Quality Improvement Project from 2012 to 2017 were used. Multivariable logistic regression was used to examine the association between perioperative RBC transfusion status and the development of new or progressive VTE within 30 days of surgery. The analyses were age stratified, as follows: neonates (≤28 days), infants (>28 days and <1 year), and children (≥1 year).

RESULTS

In this study, we included 20 492 neonates, 79 744 infants, and 382 862 children. Postoperative development of VTE was reported in 99 (0.48%) neonates, 147 (0.2%) infants, and 374 (0.1%) children. In all age groups, development of VTE was significantly more common among patients with a perioperative RBC transfusion than patients without a perioperative RBC transfusion (neonates: adjusted odds ratio [aOR] = 4.1, 95% confidence interval [CI] = 2.5-6.7; infants: aOR = 2.4, 95% CI = 1.7-3.6; children: aOR = 2.2, 95% CI = 1.7-2.9). Among children who received an intra- or postoperative transfusion, the weight-based volume of RBCs (mL/kg) transfused was associated with postoperative VTE in a dose-dependent manner: second tertile (odds ratio = 2.3, 95% CI = 1.3-4.1) and third tertile (odds ratio = 4.1, 95% CI = 2.3-7.4) versus first tertile.

CONCLUSIONS

Perioperative RBC transfusions are independently associated with development of new or progressive postoperative VTE in children, infants, and neonates. These findings need further validation in prospective studies and emphasize the need for evidence-based perioperative pediatric blood transfusion decisions.

Effect of red blood cell transfusion on short-term outcomes in very low birth weight infants

BACKGROUND

Red blood cell (RBC) transfusion improves cardiorespiratory status of preterm infants by increasing circulating hemoglobin, improving tissue oxygenation, and reducing cardiac output. However, RBC transfusion itself has also been suggested to negatively affect short-term outcomes such as intraventricular hemorrhage (IVH), bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP), and necrotizing enterocolitis (NEC) in premature infants.

PURPOSE

This study aimed to analyze the relationship between RBC transfusion and short-term outcomes in very low birth weight (VLBW) infants (birth weight, <1,500 g).

METHODS

We retrospectively reviewed the medical records of VLBW infants admitted to the Soonchunhyang University Bucheon Hospital between October 2010 and December 2017. Infants who died during hospitalization were excluded. The infants were divided into 2 groups according to RBC transfusion status. We investigated the relationship between RBC transfusion and short-term outcomes including BPD, ROP, NEC, and IVH.

RESULTS

Of the 250 enrolled VLBW infants, 109 (43.6%) underwent transfusion. Univariate analysis revealed that all shortterm outcomes except early-onset sepsis and patent ductus arteriosus were associated with RBC transfusion. In multivariate analysis adjusted for gestational age, birth weight and Apgar score at 1 minute, RBC transfusion was significantly correlated with BPD (odds ratio [OR], 5.42; P<0.001) and NEC (OR, 3.40; P= 0.009).

CONCLUSION

RBC transfusion is significantly associated with adverse clinical outcomes such as NEC and BPD in VLBW infants. Careful consideration of the patient's clinical condition and appropriate guidelines is required before administration of RBC transfusions.

Influence of enteral feeding and anemia on tissue oxygen extraction after red blood cell transfusion in preterm infants

BACKGROUND

Understanding factors that impact tissue oxygen extraction may guide red blood cell (RBC) transfusion decision making in preterm infants. Our objective was to assess the influence of enteral feeding and anemia on cerebral and mesenteric oxygen saturation (Csat and Msat) and fractional tissue oxygen extraction (cFTOE and mFTOE) over the entire time course of RBC transfusion.

STUDY DESIGN AND METHODS

Preterm, very low-birth-weight infants receiving RBC transfusions at a single center were enrolled. Near-infrared spectroscopy sensors measured Csat and Msat levels from an hour before transfusion to 24 hours after. During this period, changes in Csat, Msat, cFTOE, and mFTOE were described, and their association with enteral feeding status and pretransfusion degree of anemia were assessed using generalized estimating equations.

RESULTS

RBC transfusion data from 31 preterm infants were included. Infants receiving enteral feeds exhibited lower pretransfusion Msat. Infants with pretransfusion hematocrit greater than 30% exhibited higher pretransfusion Csat and lower pretransfusion cFTOE. Such differences in baseline measurements persisted through 24 hours after transfusion. However, no statistically significant differences in oxygenation measures over time by enteral feeding or anemia status were identified.

CONCLUSION

Compared to NPO, enteral feeding was associated with lower Msat; anemia (hematocrit ≤30%) was associated with lower Csat and higher cFTOE. Over the time course of RBC transfusion, trajectories of Csat, Msat, cFTOE and mFTOE did not differ by enteral feeding or anemia status.

Screening and novel therapies for retinopathy of prematurity - A review

With current screening for sight threatening retinopathy of prematurity (ROP) <10% of screened infants need treatment. Prediction models based on birth characteristics, postnatal weight gain and other factors have been developed to reduce examinations in low-risk infants. A model based on advanced statistics using data from >7000 infants registered in the Swedish ROP registry is being developed. Based on birth characteristics only, it appears to predict total risk of ROP-treatment as well as models including weight measurements. Treatment risk peaked at 12 weeks of age. Laser therapy is the method of choice for severe ROP. Anti-VEGF therapies are implemented worldwide despite insufficient knowledge of choice of drug, dosage and long term systemic effects. Prevention of ROP may be achieved through oxygen control and provision of the mother's breastmilk. Other interventions such as supplementation with long chain polyunsaturated fatty acids and preservation of fetal haemoglobin are investigated.

Progressive anemia of prematurity is associated with a critical increase in cerebral oxygen extraction

BACKGROUND

Elevated cerebral fractional tissue oxygen extraction (cFTOE) is an adaptation to anemia of prematurity (AOP). cFTOE ≥0.4 is associated with brain injury in infants ≤30 weeks. This longitudinal study sought to investigate the utility of cFTOE in the evaluation of AOP.

METHODS

Infants ≤30 weeks estimated gestational age (EGA) underwent weekly hemoglobin, cerebral saturation, and pulse oximetry recordings from the second through 36 weeks post-menstrual age (PMA). Recordings were excluded if they were under 1 h or if hemoglobin was not measured within 7 days of recording. Mean cFTOE was calculated for each recording. Statistical analysis used linear mixed-effects modeling and receiver operating characteristic analysis.

RESULTS

144 recordings from 39 infants (mean EGA 27.6 ± 2.2 weeks, BW 1139 ± 286 g) were included of whom 39% (15/39) were transfused. The mean recording length was 2.8 ± 1.3 h. There was a significant negative correlation between hemoglobin and cFTOE (R = -0.423, p ≤.001). In a multivariate model, adjusting for EGA, PMA, and patent ductus arteriosus treatment the AUC was 0.821. A critical increase in cFTOE occurred at a hemoglobin level of 9.6 g/dL.

CONCLUSIONS

AOP is associated with a critical increase in cFTOE that occurs at a significantly higher hemoglobin level than standard clinical thresholds for transfusion.

Impact of red blood cell transfusions on intestinal barrier function in preterm infants

OBJECTIVE

To determine the relationships of red blood cell (RBC) transfusion and enteral feeding to changes in intestinal permeability (IP) measured by the relative intestinal uptake of lactulose (La) and rhamnose (Rh) in preterm infants <33 wk gestation.

DESIGN/METHODS

Infants 240-326wk gestation received La/Rh solution enterally on study days 1, 8 and 15.Urinary La/Rh ratio was measured by HPLC. Hematocrit preceding transfusion, total RBC transfusion volume, volume/kg, and feeding status during each study interval (birth-d1; d1-d8, and d8-d15) were determined.

RESULTS

Of the seventeen (40.5%) subjects who received≥1 transfusion during the study period, 12 (70.6%) infants were <28 wk gestation and 5 (29.4%) infants were≥28 wk gestation, p < 0.0001. Lower pre-transfusion hematocrit was observed in intervals preceding high IP (La/Rh > 0.05) than in intervals preceding low IP (La/Rh≤0.05) measurements (33 vs 35.8, p = 0.1051). RBC transfusions occurred more frequently in intervals preceding high IP than in intervals preceding low IP (26.8%; vs 8.3%, p = 0.0275) with 5-fold higher total RBC volume and volume/kg in intervals preceding any time point with high IP. RBC transfusion during an interval was associated with a three-fold increased risk of high IP (aOR 2.7; 95% C.I 0.564-12.814; p = 0.2143). Exclusive breast milk exposure and post-menstrual age reduced the risk for high IP following RBC transfusion.

CONCLUSIONS

Both RBC transfusion number and volume was associated with subsequent high IP measurements in preterm infants <33 weeks gestation and potentially may contribute to impairment of the preterm intestinal barrier.

Anemia induces gut inflammation and injury in an animal model of preterm infants

BACKGROUND

While very low birth weight (VLBW) infants often require multiple red blood cell transfusions, efforts to minimize transfusion-associated risks have resulted in more restrictive neonatal transfusion practices. However, whether restrictive transfusion strategies limit transfusions without increasing morbidity and mortality in this population remains unclear. Recent epidemiologic studies suggest that severe anemia may be an important risk factor for the development of necrotizing enterocolitis (NEC). However, the mechanism whereby anemia may lead to NEC remains unknown.

STUDY DESIGN AND METHODS

The potential impact of anemia on neonatal inflammation and intestinal barrier disruption, two well-characterized predisposing features of NEC, was defined by correlation of hemoglobin values to cytokine levels in premature infants and by direct evaluation of intestinal hypoxia, inflammation and gut barrier disruption using a pre-clinical neonatal murine model of phlebotomy-induced anemia (PIA).

RESULTS

Increasing severity of anemia in the preterm infant correlated with the level of IFN-gamma, a key pro-inflammatory cytokine that may predispose an infant to NEC. Gradual induction of PIA in a pre-clinical model resulted in significant hypoxia throughout the intestinal mucosa, including areas where intestinal macrophages reside. PIA-induced hypoxia significantly increased macrophage pro-inflammatory cytokine levels, while reducing tight junction protein ZO-1 expression and increasing intestinal barrier permeability. Macrophage depletion reversed the impact of anemia on intestinal ZO-1 expression and barrier function.

CONCLUSIONS

Taken together, these results suggest that anemia can increase intestinal inflammation and barrier disruption likely through altered macrophage function, leading to the type of predisposing intestinal injury that may increase the risk for NEC.

Elevated brain oxygen extraction fraction in preterm newborns with anemia measured using noninvasive MRI

OBJECTIVE

To test the hypothesis that cerebral oxygen extraction fraction (OEF) is elevated and inversely related to hematocrit level in anemic former very-low-birth-weight infants near term.

STUDY DESIGN

Prospective study of non-sedated preterm infants (post-menstrual age = 36 ± 2 weeks) over a range of hematocrits (0.23-0.49). Anatomical (T₁-W, T₂-W, and diffusion-weighted), cerebral blood flow (CBF), and OEF 3-T MRI were utilized. Statistical analysis included Spearman's rank-order correlation testing between study variables and intraclass correlation coefficients (ICC) calculated between consecutively acquired OEF scans.

RESULTS

Consecutive OEF measurements showed moderate-to-good agreement (ICC = 0.71; 95% CI = 0.40-0.87). OEF increased with worsening anemia (ρ = -0.58; p = 0.005), and OEF and basal ganglia CBF were positively correlated (ρ = 0.49; p = 0.023).

CONCLUSION

Noninvasive OEF MRI has moderate-to-good repeatability in non-sedated former preterm infants nearing term-equivalent age. Strong correlation of elevated OEF with anemia suggests hemodynamic compensation for anemia and could establish OEF as a useful biomarker of transfusion threshold for preterm infants.

Impact of Blood Donor Sex on Transfusion-Related Outcomes in Preterm Infants

OBJECTIVE

Explore the role of red blood cell donor sex on preterm infant neonatal outcomes.

STUDY DESIGN

In a retrospective, exploratory, cohort study, the hospital blood bank database was queried for units of blood released to neonatal intensive care unit patients in 2009-2010. The state blood center provided donor sex, and a department database provided neonatal characteristics and morbidities. Comparisons were made for 2 groups: those who ever received female blood and those who did not.

RESULTS

Among 462 infants <32 weeks of gestation, 190 (41%) received >1 blood transfusion. In univariate analyses, compared with infants who received only male blood, infants who received female donor blood had higher rates of bronchopulmonary dysplasia (38% vs 22%; P = .03), spontaneous intestinal perforation/necrotizing enterocolitis (17% vs 6%; P = .04), and death or any morbidity (60% vs 38%; P < .01), respectively. In adjusted analyses, female blood was associated with any morbidity (P = .0251) and 21 days longer hospitalization (P = .0098). After adding total number transfusions to the model, only an increased number of transfusions was associated with bronchopulmonary dysplasia (P = .0009), any morbidity (P = .0001), and length of stay (P = .0001). In subset regressions comparing exclusively female donor blood with male donor blood, there was a significant interaction of female donor blood and number of transfusions for any morbidity (OR 2.6 95% CI 1.2-5.7, P = .01).

CONCLUSIONS

Preliminary findings suggest that female donor blood was associated with preterm vulnerability to neonatal morbidities.

Recent advances in transfusions in neonates/infants

Transfusions of red blood cells (RBCs), platelets, and plasma are critical therapies for infants and neonates (particularly preterm neonates) in the neonatal intensive care unit, who are the most frequently transfused subpopulation across all ages. Although traditionally a significant gap has existed between the blood utilization and the evidence base essential to adequately guide transfusion practices in infants and neonates, pediatric transfusion medicine is evolving from infancy and gradually coming of age. It is entering an exciting era with recognition as an independent discipline, a new and evolving high-quality evidence base for transfusion practices, novel technologies and therapeutics, and national/international collaborative research, educational, and clinical efforts. Triggers and thresholds for red cell transfusion are accumulating evidence with current phase III clinical trials. Ongoing trials and studies of platelet and plasma transfusions in neonates are anticipated to provide high-quality evidence in years to come. This article aims to summarize the most current evidence-based practices regarding blood component therapy in neonates. Data on the use of specific components (RBCs, plasma, and platelets) are provided. We attempt to define thresholds for anemia, thrombocytopenia, and abnormal coagulation profile in neonates to highlight the difficulties in having a specific cutoff value in neonates and preterm infants. Indications for transfusion of specific products, transfusion thresholds, and current practices and guidelines are provided, and possible adverse outcomes and complications are discussed. Finally, the critical research knowledge gaps in these practices as well as ongoing and future research areas are discussed. In an era of personalized medicine, neonatal transfusion decisions guided by a strong evidence base must be the overarching goal, and this underlies all of the strategic initiatives in pediatric and neonatal transfusion research highlighted in this article.

Patient blood management, what does this actually mean for neonates and infants?

Patient blood management (PBM) refers to an evidence-based package of care that aims to improve patient outcomes by optimal use of transfusion therapy, including managing anaemia, preventing blood loss and improving anaemia tolerance in surgical and other patients who may need transfusion. In adults, PBM programmes are well established, yet the definition and implementation of PBM in neonates and children lags behind. Neonates and infants are frequently transfused, yet they are often under-represented in transfusion trials. Adult PBM programmes may not be directly applicable to these populations. We review the literature in neonatal (and applicable paediatric) transfusion medicine and propose specific neonatal PBM definitions and elements.

Cryoprecipitate transfusions in the neonatal intensive care unit: a performance improvement study to decrease donor exposure

BACKGROUND

The objective of this study was to determine if a change in cryoprecipitate transfusion policy impacts donor exposure and fibrinogen level in a neonatal intensive care unit (NICU) population.

STUDY DESIGN AND METHODS

The cryoprecipitate policy was changed from transfusing 10ml/kg to a maximum of 1 unit per transfusion in January 2013. Data were obtained via retrospective chart review of all infants receiving cryoprecipitate transfusions from January 2008 to February 2015 in the NICU at Christiana Hospital.

RESULTS

A total of 103 neonates received a total of 144 cryoprecipitate transfusions. Before the policy change, term babies were more likely to be exposed to more than one donor compared to preterm babies (75% vs. 6%, p < 0.01). After the policy change, no babies were exposed to greater than one donor per transfusion and there were similar increases in posttransfusion fibrinogen level as before the policy change.

CONCLUSION

Limiting cryoprecipitate transfusions to 1 unit per transfusion decreased donor exposure in infants without negatively impacting posttransfusion fibrinogen levels. This is especially evident in term neonates.

Comparison of neonatal red cell transfusion reporting in neonatal intensive care units with blood product issue data: a validation study

BACKGROUND

Infants in Neonatal Intensive Care Units represent a heavily transfused population, and are the focus of much research interest. Such research commonly relies on custom research databases or routinely collected data. Knowledge of the accuracy of transfusion recording in these databases is important. This study aims to assess the reporting of red blood cell transfusion neonatal intensive care unit data compared with routinely collected hospital blood bank ("Blood Watch") data.

METHODS

Blood Watch data was linked with the NICUS Data Collection, and with routinely collected birth and hospital data for births between 2007 and 2010. The sensitivity, specificity, and positive and negative predictive values for transfusion were calculated, compared to the Blood Watch data. The agreement between the NICUS and Blood Watch datasets on quantity transfused was also assessed.

RESULTS

Data was available on 3934 infants, of which 16.2% were transfused. Transfusion was reported in the NICUS Data Collection with high specificity (98.3%, 95% confidence interval (97.8%,98.7%)), but with some under-enumeration (sensitivity 89.2% (95% CI 86.5%,91.5%)). There was excellent agreement between the NICUS and Blood Watch datasets on quantity transfused (Kappa 0.90, 95% CI (0.88,0.92)). Transfusion reporting in the hospital data for these infants was also reliably reported (Sensitivity 83.7% (95% CI 80.6%,86.5%), specificity 99.1% (95% CI 98.7%,99.4%)).

CONCLUSIONS

Transfusion is reliably reported in the neonatal intensive care unit data, with some under-reporting, and quantity transfused is well recorded. The NICUS Data Collection provides useful information on blood transfusions, including quantity of blood transfused in a high risk population.

Red Blood Cell Transfusion in Preterm Infants: Current Evidence and Controversies

The current evidence regarding the indication, advantages and risks of red blood cell transfusion (RBCT) for preterm infants is discussed. This is an important area in Neonatology to be examined given that 90% of extremely low birth weight infants receive RBCT and many controversies remain regarding when to transfuse and the risks of RBCT. The various treatment thresholds and guidelines used are presented and we compare the short-term clinical benefits of liberal and restrictive RBCT in preterm infants; the majority of these are equivocal and sadly long-term outcome data is limited. The latest evidence on how anaemia and blood transfusion affect organ perfusion in preterm infants is presented. This is important when trying to establish the optimal trigger threshold for RBCT in preterm infants, especially because the knowledge about the adaptive physiological responses to anaemia in very low birth weight infants and the effects of RBCT at various levels of anaemia is also inadequate. Further research into the physiological adaptive response to anaemia of varying degrees and to RBCT at different levels of anaemia in preterm infants of different gestational and post-natal ages is needed before we can conclusively guide the optimal timing and trigger thresholds for RBCT in preterm infants.

A Theoretical and Practical Approach to Defining "Adequate Oxygenation" in the Preterm Newborn

John Scott Haldane recognized that the administration of supplemental oxygen required titration in the individual. Although he made this observation in adults, it is equally applicable to the preterm newborn. But how, in practice, can the oxygen requirements in the preterm newborn be determined to avoid the consequences of too little and too much oxygen? Unfortunately, the current generation of oxygen saturation trials in preterm newborns guides saturation thresholds rather than individual oxygen requirements. For this reason, we propose an alternate model for the description of oxygen sufficiency. This model considers the adequacy of oxygen delivery relative to simultaneous consumption. We describe how measuring oxygen extraction or the venous oxygen reservoir could define a physiologically based definition of adequate oxygen. This definition would provide a clinically useful reference value while making irrelevant the absolute values of both oxygen delivery and consumption. Additional trials to test adjunctive, noninvasive measurements of oxygen status in high-risk preterm newborns are needed to minimize the effects of both insufficient and excessive oxygen exposure.