Red blood cell transfusion, feeding and necrotizing enterocolitis in preterm infants

Understanding necrotizing enterocolitis endotypes and acquired intestinal injury phenotypes from a historical and artificial intelligence perspective

Necrotizing enterocolitis (NEC) remains a devastating disease in preterm and term neonates. Despite significant progress made in understanding NEC pathogenesis over the last 50 years, the inability of current definitions to discriminate the various pathophysiological processes underlying NEC has led to an umbrella term that limits clinical and research progress. In this mini review, we provide a historical perspective on how NEC definitions and pathogenesis have evolved to our current understanding of NEC endotypes. We also discuss how artificial intelligence-based approaches are influencing our knowledge of risk-factors, classification and prognosis of NEC and other neonatal intestinal injury phenotypes.

Transfusion-associated necrotising enterocolitis in very low birth weight babies: transfusion and feeding practices in two neonatal units in Bloemfontein, Free State

Background

Necrotising enterocolitis (NEC) is life-threatening with a rising incidence due to improved neonatal care. While researchers' focus has shifted to causes, risk factors and preventative clinical strategies, little is known about the exact aetiology of NEC. Risk factors include the relationship between red blood cell transfusions (RBCTs) and the development of transfusion-associated NEC (TANEC) and peri-transfusion feeding, increasing the risk of TANEC.

Objectives

Evaluate the relationship between RBCT and peri-transfusion feeding practices and the development of TANEC in very low birthweight (VLBW) neonates over 5 years.

Methods

This was a retrospective analytical record review of all VLBW neonates admitted to two tertiary hospitals' neonatal units in Bloemfontein, South Africa (SA), from 1 January 2012 - 31 December 2016.

Results

The study population (n=1 426) had a median birthweight of 1 260 g and a median gestation age of 30 weeks. RBCTs were given to 41.9%, and NEC developed in 7.4%, of whom 47.6% had an RBCT (TANEC). Half (47.2%) were kept nil per os (NPO) around the transfusion. No association was found between NPO status and TANEC development (8.9% NPO patients, 7.9% non-NPO patients, p=0.6826). No significant differences regarding Modified Bell's Staging were found between neonates who developed TANEC v. NEC.

Conclusion

Optimising the administration of RBCTs and evidence-based feeding protocols is crucial in reducing TANEC's impact on premature neonates.

Contribution of the study

The study examines the link between red blood cell transfusion and transfusion-associated necrotising enterocolitis in very low birthweight neonates. It highlights the need for evidence-based feeding protocols to reduce transfusion-associated necrotising enterocolitis risk during transfusions. It calls for standardised clinical guidelines to improve neonatal outcomes and lower necrotising enterocolitis and transfusion-associated necrotising enterocolitis incidence.

Effects of the feeding protocol during blood transfusion on splanchnic tissue oxygenation and complications in very premature infants

Background

The effects of blood transfusions on splanchnic oxygenation and complications related to blood transfusions, including red blood cell (RBC) transfusions, in premature infants undergoing enteral feeding, to provide clinical evidence for a management protocol for premature infants during the peri-transfusion period.

Methods

This single-blind, randomized, controlled trial enrolled sixty eligible preterm infants who were randomly divided into the withholding feeding group (n = 30) or feeding group (n = 30). Enteral feeding was withheld for 8 h, beginning from the start of transfusion infants in the feeding group were fed according to the pre-transfusion feeding approach during and after RBC transfusion.

Results

Baseline characteristics of those in the withholding and feeding groups were as follows: gestational age (weeks) 27.52 (24.86-30.14) and 27.13 (25.43-30.14); birth weight (g), 1,027 (620-1,450) and 1,027 (620-1,270); blood transfusion day, 48 (14-79) and 39 (10-78); and hemoglobin before blood transfusion (g/L), 81.67 (±10.56) and 85.93 (±14.77). No significant differences were observed between groups at baseline. No significant differences were observed in the average splanchnic tissue oxygenation changes or clinical results at any time. One patient in the withholding feeding group experienced transfusion-associated necrotizing enterocolitis.

Conclusions

No differences in splanchnic oxygenation observed these feeding protocols. This study suggests the feasibility of a sizable trial to evaluate clinical outcomes. The risks of mesenteric ischemia and transfusion-related necrotizing enterocolitis for premature infants were not increased by enteral feeding during RBC transfusion.

Clinical trial registration

ChiCTR2200055726 (https://www.chictr.org.cn/).

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.

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.

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.

The Recipient Epidemiology and Donor Evaluation Study-IV-Pediatric (REDS-IV-P): A research program striving to improve blood donor safety and optimize transfusion outcomes across the lifespan

BACKGROUND

The Recipient Epidemiology and Donor Evaluation Study-IV-Pediatric (REDS-IV-P) is a new iteration of prior National Heart, Lung, and Blood Institute (NHLBI) REDS programs that focus on improving transfusion recipient outcomes across the lifespan as well as the safety and availability of the blood supply.

STUDY DESIGN AND METHODS

The US program includes blood centers and hospitals (22 including 6 free-standing Children's hospitals) in four geographic regions. The Brazilian program has 5 participating hemocenters. A Center for Transfusion Laboratory Studies (CTLS) and a Data Coordinating Center (DCC) support synergistic studies and activities over the 7-year REDS-IV-P program.

RESULTS

The US is building a centralized, vein-to-vein (V2V) database, linking information collected from blood donors, their donations, the resulting manufactured components, and data extracts from hospital electronic medical records of transfused and non-transfused patients. Simultaneously, the Brazilian program is building a donor, donation, and component database. The databases will serve as the backbone for retrospective and prospective observational studies in transfusion epidemiology, transfusion recipient outcomes, blood component quality, and emerging blood safety issues. Special focus will be on preterm infants, patients with sickle cell disease, thalassemia or cancer, and the effect of donor biologic variability and component manufacturing on recipient outcomes. A rapid response capability to emerging safety threats has resulted in timely studies related to Severe Acute Respiratory Syndrome Corona Virus-2 (SARS-CoV-2).

CONCLUSIONS

The REDS-IV-P program endeavors to improve donor-recipient-linked research with a focus on children and special populations while also maintaining the flexibility to address emerging blood safety issues.

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.

Risk factors of necrotizing enterocolitis in neonates with sepsis: A retrospective case-control study

Sepsis, a severe infectious disease in the neonatal period, is considered a risk factor for necrotizing enterocolitis (NEC). To investigate the specific risk factors for NEC in septic infants, septic infants admitted to our center from January 2010 to April 2018 were included. Septic neonates with proven NEC (Bell's stage ⩾II) were enrolled in the NEC group, and those without NEC were enrolled in the control group. Demographics, clinical characteristics, and risk factors were compared between the two groups. Univariate and logistic regression analyses were used to evaluate the potential risk factors for NEC. A total of 610 septic neonates were included, of whom 78 (12.8%) had complicated NEC. The univariate analysis indicated that infants with NEC had a lower birth weight, a lower gestational age, and older age on admission than those without NEC (P < 0.05). Higher rates of anemia, prolonged rupture of membranes (PROM) (⩾18 h), pregnancy-induced hypertension, late-onset sepsis (LOS), red blood cell transfusion and hypoalbuminemia were observed in the NEC group than in the non-NEC group (P<0.05). Logistic regression analysis revealed LOS (P = 0.000), red blood cell transfusion (P = 0.001) and hypoalbuminemia (P = 0.001) were associated with the development of NEC. Among NEC infants, those who needed red blood cell transfusion had a longer hospitalization duration than those who did not need transfusion (P < 0.05). LOS, red blood cell transfusion and hypoalbuminemia were independent risk factors for the development of NEC in infants with sepsis. Taking measures to reduce the occurrence of hypoproteinemia and severe anemia may help to reduce the occurrence of NEC in septic neonates.

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.

Postoperative outcomes based on crystalloid administration in pediatric patients with necrotizing enterocolitis undergoing laparotomy

Intravenous fluid prescription is an essential part of postoperative care and may play a causal role in postoperative complications. The objective of the present study was to evaluate the relationship between intraoperative fluid administration and postoperative outcomes in a large cohort of pediatric patients.This analysis included a retrospective review of 172 patients who underwent gastroenterological surgery from January 2012 to September 2018 at an academic tertiary care hospital. Patients were evaluated based on the median amount of corrected crystalloids and subsequently dichotomized as low (<25.89 mL/kg h) versus high (>25.89 mL/kg h). The primary outcome measure was the postoperative length of hospital stay (pLOS). Secondary outcome measures included the postoperative time to restore gastroenterological functions and postoperative complications.Patients who received larger amounts of crystalloids were more likely to have a lower intraoperative level of hemoglobin (P = .78) and an intraoperative blood transfusion (P = .27). There were trends toward lower incidence rates of hyperchloremic acidosis (P = .375) and metabolic acidosis (P = .54) in the high crystalloid administration cohort. The incidence of postoperative complications increased as the amount of administered fluid decreased (P = .046). The total length of hospital stay was shorter in patients who received high volumes of crystalloid fluid (19.5 [15.75-32.25] days) than in patients who received low volumes (22 [16-29.5] days, P = .283).Significant and multifaceted variability in crystalloid administration was noted among pediatric patients undergoing major surgery. High fluid administration was associated with favorable postoperative outcomes; these findings could be applied to improve patient safety and facilitate better quality of care.

Abnormal Splanchnic Regional Saturations in a Preterm Infant That Developed Necrotizing Enterocolitis Following a Red Blood Cell Transfusion

BACKGROUND

Necrotizing enterocolitis (NEC) has been associated with red blood cell (RBC) transfusions in preterm infants. Near-infrared spectroscopy (NIRS) can be used to noninvasively monitor regional oxygen saturations (rSO2).

CLINICAL FINDINGS

This former 28-week female premature infant, 29 days old, received an RBC transfusion due to increased apneic spells and a hematocrit of 27%. Within 24 hours she developed abdominal distension and passed a bloody stool (Bell's stage 2 NEC on abdominal x-ray). She completed 7 days of antibiotics and nothing-by-mouth status and was discharged home on room air and oral feedings on day of life 70.

PRIMARY DIAGNOSIS

We describe the presentation of NEC following a RBC transfusion in a preterm infant monitored with cerebral and splanchnic NIRS.

INTERVENTIONS

Mean rSO2 (cerebral and splanchnic) measurements were continuously recorded and calculated in 30-minute periods at baseline (prior to packed RBC transfusion), every hour during the RBC transfusion, and every 3 hours for the following 48 hours.

OUTCOMES

In this infant, average baseline splanchnic rSO2 was low at 46.5%, and increased during transfusion to 65%. However, following the RBC transfusion and an enteral feeding, splanchnic rSO2 dramatically decreased to 26%, and remained low until the time of NEC diagnosis.

PRACTICE RECOMMENDATIONS

To develop awareness of the increased risk for NEC in premature infants with significant anemia that receive packed RBC transfusions. With further studies and education, NIRS could be a valuable tool for the nurses and medical team to identify these at-risk neonates.

A significant decrease in hemoglobin concentrations may predict occurrence of necrotizing enterocolitis in preterm infants with late-onset sepsis

OBJECTIVE

This study aimed to examine the clinical value of a decrease in hemoglobin concentration (HC) after the onset of sepsis for predicting occurrence of necrotizing enterocolitis (NEC) in preterm infants with late-onset sepsis.

METHODS

We performed a retrospective cohort study between January 2015 and January 2020. Premature neonates (gestational age <37 weeks) with late-onset sepsis (age >3 days) were enrolled. According to the degree of reduction in HC, neonates were divided into the non-decrease group, mild decrease group, and severe decrease group. Demographic data, perinatal conditions, blood cell count analysis, blood culture, and treatment measures were compared.

RESULTS

Eighty premature infants with sepsis were studied. The mortality rate and incidence of NEC were significantly higher in the severe decrease group than in the non-decrease and mild decrease groups. Significant differences were observed in the decrease in HC, red blood cell transfusion, and ventilator application between the NEC and non-NEC groups. A significant decrease in HC was an independent risk factor for NEC in preterm infants with sepsis.

CONCLUSION

A significant decrease in HC is an independent risk factor for NEC and may predict the occurrence of NEC in preterm infants with sepsis.

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.

Association of Bolus Feeding With Splanchnic and Cerebral Oxygen Utilization Efficiency Among Premature Infants With Anemia and After Blood Transfusion

IMPORTANCE

The pathogenesis of transfusion-associated necrotizing enterocolitis remains elusive. Splanchnic hypoperfusion associated with packed red blood cell transfusion (PRBCT) and feeding has been implicated, but studies of splanchnic tissue oxygenation with respect to feeding plus PRBCT are lacking.

OBJECTIVE

To investigate the oxygen utilization efficiency of preterm gut and brain challenged with bolus feeding during anemia and after transfusion using near-infrared spectroscopy.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study conducted from September 1, 2014, to November 30, 2016, at a tertiary neonatal intensive care unit included 25 hemodynamically stable infants with gestational age less than 32 weeks, birth weight less than 1500 g, and postmenstrual age younger than 37 weeks. Data analysis was performed from August 1, 2017, to October 31, 2018.

EXPOSURES

Infants received PRBCT (15 mL/kg for 4 hours) and at least 120 mL/kg daily of second hourly bolus feedings.

MAIN OUTCOMES AND MEASURES

Splanchnic fractional tissue oxygen extraction (FTOEs) and cerebral fractional tissue oxygen extraction (FTOEc) measures were made during 75-minute feeding cycles that comprised a 15-minute preprandial feeding phase (FP0) and 4 contiguous 15-minute postprandial feeding phases (FP1, FP2, FP3, and FP4; each 15 minutes long). The intraindividual comparisons of feeding-related changes were evaluated during the pretransfusion epoch (TE0: 4 hours before onset of transfusion) and 3 TEs after transfusion (TE1: first 8 hours after PRBCT completion; TE2: 9-16 hours after PRBCT completion; and TE3: 17-24 hours after PRBCT completion).

RESULTS

Of 25 enrolled infants (13 [52%] female; median birth weight, 949 g [interquartile range {IQR}, 780-1100 g]; median gestational age, 26.9 weeks [IQR, 25.9-28.6 weeks]; median enrollment weight, 1670 g [IQR, 1357-1937 g]; and median postmenstrual age, 34 weeks [IQR, 32.9-35 weeks]), 1 infant was excluded because of corrupted near-infrared spectroscopy data. No overall association was found between FTOEs and FPs in a multivariable repeated-measures model that accounted for transfusion epochs (primary analysis approach) (FP0: mean estimate, 11.64; 95% CI, 9.55-13.73; FP1: mean estimate, 12.02; 95% CI, 9.92-14.11; FP2: mean estimate, 12.77; 95% CI, 10.68-14.87; FP3: mean estimate, 12.54; 95% CI, 10.45-14.64; FP4: mean estimate, 12.98; 95% CI, 10.89-15.08; P = .16 for the FP association). However exploratory analyses of postprandial changes in FTOEs undertaken for each transfusion epoch separately found evidence of increased postprandial FTOEs during TE1 (mean [SD] FTOEs, 10.55 [5.5] at FP0 vs 13.21 [5.96] at FP4, P = .046). The primary and exploratory analyses found no association between FTOEc and feeding phases, suggesting that cerebral oxygenation may be protected.

CONCLUSIONS AND RELEVANCE

The findings suggest that enteral feeding may be associated with gut ischemia and potentially transfusion-associated necrotizing enterocolitis. The postprandial changes in FTOEs appear to warrant further investigation in larger randomized studies.

An experience with a bubble CPAP bundle: is chronic lung disease preventable?

BACKGROUND

Continuous positive airway pressure (CPAP) is associated with marginal decrease in chronic lung disease (CLD). This study aims to report outcomes, with focus on CLD, of preterm infants managed with a bubble CPAP (b-CPAP) bundle of care.

METHODS

Infants <1500 g were stratified into four groups depending on intubation status through first 3 days of life. The incidence of mortality, CLD and other morbidities were compared over four chronological epochs. Outcomes of the most recent epoch were compared to contemporaneous benchmarks from Vermont Oxford Network (VON).

RESULTS

Of 773 infants (median GA = 28 weeks, average BW = 995 g), 24.5% were intubated in DR and 11.7% in the first day of life. Mechanical ventilation, bCPAP and oxygen days in survivors were 1.5, 29 and 14, respectively. Overall incidence of CLD was 6.4% that remained consistent in the four epochs (7.6%, 7.5%, 5.8% and 5%), respectively. In comparison to VON, CLD was significantly less (p < 0.001). Initial DR intubation was not associated with increased CLD compared to initial management with CPAP that required subsequent intubation.

CONCLUSION

It is feasible and sustainable to administer a b-CPAP bundle of care to decrease CLD. Cluster randomized trials are needed to validate the reproducibility of this approach.

Stopping enteral feeds for prevention of transfusion-associated necrotising enterocolitis in preterm infants

BACKGROUND

Feeding practices around the time of packed red blood cell transfusion have been implicated in the subsequent development of necrotising enterocolitis (NEC) in preterm infants. Specifically, it has been suggested that withholding feeds around the time of transfusion may reduce the risk of subsequent NEC. It is important to determine if withholding feeds around transfusion reduces the risk of subsequent NEC and associated mortality.

OBJECTIVES

• To assess the benefits and risks of stopping compared to continuing feed management before, during, and after blood transfusion in preterm infants • To assess the effects of stopping versus continuing feeds in the following subgroups of infants: infants of different gestations; infants with symptomatic and asymptomatic anaemia; infants who received different feeding schedules, types of feed, and methods of feed delivery; infants who were transfused with different blood products, at different blood volumes, via different routes of delivery; and those who received blood transfusion with and without co-interventions such as use of diuretics • To determine the effectiveness and safety of stopping feeds around the time of a blood transfusion in reducing the risk of subsequent necrotising enterocolitis (NEC) in preterm infants SEARCH METHODS: We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 11), in the Cochrane Library; MEDLINE (1966 to 14 November 2018); Embase (1980 to 14 November 2018); and the Cumulative Index to Nursing and Allied Health Literature (CINAHL; 1982 to 14 November 2018). We also searched clinical trials databases, conference proceedings, and reference lists of retrieved articles for randomised controlled trials (RCTs), cluster-RCTs, and quasi-RCTs.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials that compared stopping feeds versus continuing feeds around the time of blood transfusion in preterm infants.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, assessed trial quality, and extracted data from the included studies.

MAIN RESULTS

The search revealed seven studies that assessed effects of stopping feeds during blood transfusion. However, only one RCT involving 22 preterm infants was eligible for inclusion in the review. This RCT had low risk of selection bias but high risk of performance bias, as care personnel were not blinded to the study allocation. The primary objective of this trial was to investigate changes in mesenteric blood flow, and no cases of NEC were reported in any of the infants included in the trial. We were unable to draw any conclusions from this single study. The overall GRADE rating for quality of evidence was very low.

AUTHORS' CONCLUSIONS

Randomised controlled trial evidence is insufficient to show whether stopping feeds has an effect on the incidence of subsequent NEC or death. Large, adequately powered RCTs are needed to address this issue.

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.

The WHEAT pilot trial-WithHolding Enteral feeds Around packed red cell Transfusion to prevent necrotising enterocolitis in preterm neonates: a multicentre, electronic patient record (EPR), randomised controlled point-of-care pilot trial

INTRODUCTION

Necrotising enterocolitis (NEC) is a potentially devastating neonatal disease. A temporal association between red cell transfusion and NEC is well described. Observational data suggest that withholding enteral feeds around red cell transfusions may reduce the risk of NEC but this has not been tested in randomised trials; current UK practice varies. Prevention of NEC is a research priority but no appropriately powered trials have addressed this question. The use of a simplified opt-out consent model and embedding trial processes within existing electronic patient record (EPR) systems provide opportunities to increase trial efficiency and recruitment.

METHODS AND ANALYSIS

We will undertake a randomised, controlled, multicentre, unblinded, pilot trial comparing two care pathways: continuing milk feeds (before, during and after red cell transfusions) and withholding milk feeds (for 4 hours before, during and for 4 hours after red cell transfusions), with infants randomly assigned with equal probability. We will use opt-out consent. A nested qualitative study will explore parent and health professional views. Infants will be eligible if born at <30+0 gestational weeks+days. Primary feasibility outcomes will be rate of recruitment, opt-out, retention, compliance, data completeness and data accuracy; clinical outcomes will include mortality and NEC. The trial will recruit in two neonatal networks in England for 9 months. Data collection will continue until all infants have reached 40+0 corrected gestational weeks or neonatal discharge. Participant identification and recruitment, randomisation and all trial data collection will be embedded within existing neonatal EPR systems (BadgerNet and BadgerEPR); outcome data will be extracted from routinely recorded data held in the National Neonatal Research Database.

ETHICS AND DISSEMINATION

This study holds Research Ethics Committee approval to use an opt-out approach to consent. Results will inform future EPR-embedded and data-enabled trials and will be disseminated through conferences, publications and parent-centred information.

TRIAL REGISTRATION NUMBER

ISRCTN registry ISRCTN62501859; Pre-results.

A murine neonatal model of necrotizing enterocolitis caused by anemia and red blood cell transfusions

Necrotizing enterocolitis (NEC) is an idiopathic, inflammatory bowel necrosis of premature infants. Clinical studies have linked NEC with antecedent red blood cell (RBC) transfusions, but the underlying mechanisms are unclear. Here we report a neonatal murine model to investigate this association. C57BL/6 mouse pups rendered anemic by timed phlebotomy and then given RBC transfusions develop NEC-like intestinal injury with prominent necrosis, inflammation, and submucosal edema/separation of the lamina propria in the ileocecal region and colon within 12-24 h. The anemic intestine is infiltrated by inflammatory macrophages, which are activated in situ by RBC transfusions via a Toll-like receptor (TLR)-4-mediated mechanism and cause bowel injury. Chelation of RBC degradation products with haptoglobin, absence of TLR4, macrophage depletion, and inhibition of macrophage activation is protective. Intestinal injury worsens with increasing severity and the duration of anemia prior to transfusion, indicating a need for the re-evaluation of current transfusion guidelines for premature infants.

Relationship of Necrotizing Enterocolitis Rates to Adoption of Prevention Practices in US Neonatal Intensive Care Units

BACKGROUND

Applying quality improvement methods has reduced necrotizing enterocolitis (NEC) in some neonatal intensive care units (NICUs) by 40% to 90%.

PURPOSE

This study was conducted to (1) examine relationships between adoption of prevention practices using the NEC-Zero adherence score and NEC rates, and (2) describe implementation strategies NICUs use to prevent NEC.

METHODS

A descriptive cross-sectional correlational study was completed among US quality improvement-focused NICUs. Relationships of the NEC-Zero adherence score to NEC rates were examined. Subgroup analyses explored relationships of a human milk adherence subscore and differences between high NEC rate (≥8%) and low NEC rate (≤2%) NICUs.

RESULTS

NICUs (N = 76) ranged in size from 18 to 114 beds. The mean adherence score was 7.3 (standard deviation = 1.7; range, 3-10). The 10-point adherence score was not related to the NEC rate. The human milk subscore related to lower NEC rates (Rho = -0.26, P = .049), as was colostrum for oral care (Rho = -0.27, P = .032). The units that used a feeding protocol showed higher NEC rates (Rho = 0.27, P = .03), although very few addressed the use of effective implementation strategies to track adherence or to ensure consistency among clinicians. The units that used colostrum for oral care were more likely to adopt strategies to limit inappropriate antibiotic exposure (Rho = 0.34, P = .003).

IMPLICATIONS FOR PRACTICE

Broader use of evidence-based implementation strategies could bolster delivery of NEC prevention practices. Maternal lactation support is paramount.

IMPLICATIONS FOR RESEARCH

Future studies are needed to identify how individual clinicians deliver prevention practices, to find the extent to which this relates to overall delivery of prevention, and to study effects of bundles on NEC outcomes.

Feeding during transfusion and the risk of necrotizing enterocolitis in preterm infants

OBJECTIVE

To evaluate the effect of withholding feeds during transfusion on transfusion associated acute gut injury (TRAGI).

STUDY DESIGN

Data were collected on 125 preterm infants before and after the practice of withholding feeds for 12-24 h during transfusion was instituted. Logistic regression was used to examine effects of withholding feeds on TRAGI rates.

RESULTS

A total of 19 (15%) infants developed NEC; 6/19 (32%) had TRAGI. Postnatal hydrocortisone use was associated with TRAGI (OR 8.97; 95% CI 1.17-68.46, p = 0.034). There was no difference in NEC rates (15.8 vs. 14.7%) and the proportions (22.2 vs. 40%) of TRAGI in the two time periods before and after instituting the standardized feeding regimen and practice of holding feeds during transfusion.

CONCLUSION

No significant decrease was noted in the rates of TRAGI after feeds were withheld during transfusion. Further studies are warranted to explore the relationship between feeds during transfusion and NEC.

Effect of withholding feeds on transfusion-related acute gut injury in preterm infants: a pilot randomized controlled trial

Background: Several retrospective studies have reported an increase in necrotizing enterocolitis (NEC) during the 48 h following red blood cell (RBC) transfusion. Whether withholding enteral feeding during transfusion decreases the risk of transfusion-associated acute gut injury (TRAGI) in preterm infants is unclear.Study design and methods: In this pilot study, 112 preterm infants with gestational age ≤32 weeks and/or birth weight ≤1500 g were randomly assigned to withholding (NPO) or continuance of feeding (FED) during RBC transfusion. Primary outcome measure was development of NEC (stage ≥ 2) within 72 h of a transfusion and the change in abdominal circumference.Results: One hundred fifty-four transfusion episodes (74 NPO and 80 FED) were analyzed. Demographic characteristics were found to be similar in both groups. There was no difference in rates of NEC (0 versus 3.4%; p = .49) between the NPO and FED groups. The incidence of feeding intolerance was higher in the FED group; however, it was statistically insignificant (1.9 versus 6.8%, p = .36). Abdominal circumference remained similar in both groups in all three consecutive days following transfusion (p>.05).Conclusion: This pilot study does not support withholding feedings during transfusion but is not adequately powered to test the hypothesis that NPO decreases NEC rates. Adequately powered well-designed multicenter trials are still required.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Epidemiology of Necrotizing Enterocolitis: New Considerations Regarding the Influence of Red Blood Cell Transfusions and Anemia

This article summarizes available evidence on the relationship between red blood cell transfusion and anemia, and necrotizing enterocolitis (NEC). We review recent studies that highlight the uncertainty of the effect of red blood cell transfusion on NEC and the potential role of anemia. We also discuss potential pathophysiologic effects of both red blood cell transfusion and anemia and highlight strategies to prevent anemia and red blood cell transfusion. We also discuss ongoing randomized trials that are likely to provide important new evidence to guide red blood cell transfusion practices.

Modifiable Risk Factors in Necrotizing Enterocolitis

Multicenter groups have reported reductions in the incidence of necrotizing enterocolitis (NEC) among preterm infants over the past 2 decades. These large-scale prevalence studies have coincided with reports from multicenter consortia and single centers of modifications in practice using quality-improvement techniques aimed at either reducing NEC risk specifically or reducing risk of mortality and multiple morbidities associated with extreme prematurity. The modifications in practice have been based on mechanistic studies, epidemiologic association data, and clinical trials. Recent reports from centers modifying practice to reduce NEC are reviewed and select modified/modifiable practices discussed.

Transfusion-associated necrotizing enterocolitis in preterm infants: an updated meta-analysis of observational data

BACKGROUND

The number of observational studies that report an association between packed red blood cell (PRBC) transfusions and necrotizing enterocolitis (NEC) has increased. The primary objective of this study was to evaluate the association between PRBC transfusions and NEC in observational studies.

METHODS

Medline, Embase and Cochrane Library databases as well as the Pediatrics Academic Societies abstract archives were systematically searched to identify observational studies that investigated the association between PRBC transfusions and NEC. Key search terms included premature infant, blood transfusion and necrotizing enterocolitis. The generic inverse variance method with a random-effects model was used to meta-analyze selected studies. Odds ratios (ORs) and confidence intervals (CIs) were calculated.

RESULTS

A meta-analysis of 17 observational studies that reported the association between PRBC transfusions and NEC was performed. The meta-analysis revealed no evidence of an association between PRBC transfusions and a higher risk of NEC (OR: 0.96; 95% CI: 0.53-1.71; P=0.88). The effect estimates that suggested an association between PRBC transfusion and NEC in matched case-control studies (OR: 1.20; 95% CI: 0.58-2.47; P=0.63) differed from those reported in cohort studies (OR: 0.51; 95% CI: 0.34-0.75; P=<0.01).

CONCLUSIONS

This updated meta-analysis of predominantly low-to-moderate quality observational studies suggests that there is no significant association between PRBC transfusions and NEC. A higher quality of evidence on this topic is needed.

Transfusion practice in neonates

Neonates, especially extremely low birth weight infants, are among the groups of patients undergoing transfusion frequently. Since they are exposed to higher specific transfusion risks compared to the patients of other age groups, there are many special aspects that must be considered for transfusion therapy in neonates. The transfusion risks in neonates include adverse outcomes specific for preterm infants as well as increased metabolic, immunologic, and infectious complications. To reduce the risks of transfusion-transmitted cytomegalovirus infection and transfusion-associated graft-versus-host disease, leukoreduced and irradiated cellular blood products should be used for all neonates. This review summarizes the risks of neonatal transfusion therapy, specific methods to reduce risk, and current trends and practices of red blood cell and platelet transfusions in neonates, to facilitate decision-making for neonatal transfusion.

Transfusion-associated necrotizing enterocolitis re-evaluated: a systematic review and meta-analysis

CONTEXT

Significant controversy exists surrounding the possible association between recent packed red blood cell (PRBC) transfusion and the subsequent development of necrotizing enterocolitis (NEC) in infants. Previous studies and meta-analyses reporting a statistically significant association led to a practice change to withhold enteral feeds in the peri-transfusion period in many centers in an effort to prevent NEC; however, results from more recent studies do not support the existence of an association and, thus, question the validity of this practice change.

OBJECTIVE

This study aimed to perform a systematic review and meta-analysis to determine whether exposure to recent PRBC transfusion (defined as within 48 h) is associated with the subsequent development of NEC stage ≥II (Bell's criteria) in infants.

METHODS

Medline, Embase, CINAHL, and the Cochrane Library were searched from inception to October 7, 2015. A gray literature search was also performed. Studies comparing the risk of NEC in infants exposed and unexposed to recent PRBC transfusion were included. Thirteen studies met eligibility criteria, and 10 (n=15,675 infants) were included in the meta-analysis. Three authors independently extracted data, and meta-analysis was performed using a random effects model.

RESULTS

We found a statistically significant 45% reduction in the unadjusted odds of NEC in infants exposed to a recent PRBC transfusion (odds ratio=0.55, 95% confidence interval=0.31-0.98).

CONCLUSION

Our results show a protective effect of recent PRBC transfusion on the subsequent development of NEC. The practice of withholding enteral feeds during the peri-transfusion period should be re-evaluated in light of these results.

[Blood transfusion in neonatology: Study of practical aspects in 2016 in France, excluding acute bleeding or surgical care]

BACKGROUND

Blood transfusion is common in neonatology, especially in preterm or low birth weight infants. Recommendations were proposed by the French National Authority of Health (HAS) in 2014 and 2015 for red blood cells and platelet transfusion respectively, but an heterogeneity of practical attitudes persist. The objective of this survey is to evaluate transfusion practices in neonatal intensive care units.

METHODS

Investigation of practice of neonatal transfusion was organized among 68 neonatal intensive care unit (level 3) between September 2016 and May 2017, by mailing survey focused on systematic training of nurses, patient identification, immunohematology, information and technical aspects of blood components administration.

RESULTS

Twenty-three neonatal intensive care units among the 68s answered the questionnaire. One thousand five hundred sixty seven neonates were transfused and 3382 blood products were administered. The results highlight a consensual attitude concerning the procedures of patient identification, immunohematology tests and blood products administration. However, heterogeneity remains concerning information of the parents or the person with parental authority, immediate and delayed follow-up and devices used for the transfusion. However HAS guidelines (2014 and 2015) appear to be well applied by clinicians for blood products, specifications and calcul of transfused volume based on gestational age and weight.

Does red blood cell irradiation and/or anemia trigger intestinal injury in premature infants with birth weight ≤ 1250 g? An observational birth cohort study

BACKGROUND

Necrotizing enterocolitis (NEC) is a leading cause of neonatal morbidity and mortality in premature infants. To date, no effective biomarkers exist to predict which premature infants will develop NEC, limiting targeted prevention strategies. Multiple observational studies have reported an association between the exposure to red blood cell (RBC) transfusion and/or anemia and the subsequent development of NEC; however, the underlying physiologic mechanisms of how these factors are independently associated with NEC remain unknown.

METHODS

In this paper, we outline our prospective, multicenter observational cohort study of infants with a birth weight ≤ 1250 g to investigate the associations between RBC transfusion, anemia, intestinal oxygenation and injury that lead to NEC. Our overarching hypothesis is that irradiation of RBC units followed by longer storage perturbs donor RBC metabolism and function, and these derangements are associated with paradoxical microvascular vasoconstriction and intestinal tissue hypoxia increasing the risk for injury and/or NEC in transfused premature infants with already impaired intestinal oxygenation due to significant anemia. To evaluate these associations, we are examining the relationship between prolonged irradiation storage time (pIST), RBC metabolomic profiles, and anemia on intestinal oxygenation non-invasively measured by near-infrared spectroscopy (NIRS), and the development of NEC in transfused premature infants.

DISCUSSION

Our study will address a critical scientific gap as to whether transfused RBC characteristics, such as irradiation and metabolism, impair intestinal function and/or microvascular circulation. Given the multifactorial etiology of NEC, preventative efforts will be more successful if clinicians understand the underlying pathophysiologic mechanisms and modifiable risk factors influencing the disease.

TRIAL REGISTRATION

Our study is registered in ClinicalTrials.gov Identifier: NCT02741648 .

Anemia, red blood cell transfusions, and necrotizing enterocolitis

In the past 15 years, multiple clinical studies have identified a temporal association between red blood cell (RBC) transfusions and necrotizing enterocolitis (NEC). With some variability, most of these studies indicate that up to one-third of all cases of NEC involving very low-birth weight infants may occur within 24-48h after receiving a RBC transfusion. There is also evidence that the risk of such transfusion-associated NEC may be higher in infants transfused with the greatest severity of anemia. In this article, we summarize the clinical evidence pertaining to these issues; specifically, the contribution of RBC transfusions, and the contribution of severity of underlying anemia, to the pathogenesis of a type of NEC potentially termed, "transfusion/anemia-associated NEC."

Slow enteral feeding decreases risk of transfusion associated necrotizing enterocolitis

BACKGROUND

Necrotizing Enterocolitis (NEC) is a multifactorial condition where PRBC transfusion is associated with necrotizing enterocolitis (TANEC) in about a third of all cases of NEC. We have investigated the role of feeding practices in incidence of TANEC. We sought to compare infants diagnosed with TANEC versus infants diagnosed with classic NEC and investigated the effects of a standardized slow enteral feeding (SSEF) protocol on TANEC incidence as well as the effects of SSEF on growth of infants with NEC.

METHODS

We conducted a retrospective cohort study, where medical records of infants born in a tertiary care neonatal intensive care unit (level IIIb) from January 1997 to May 2014 with birth weight < 1500 grams and gestational age≤34 weeks with NEC stage IIa or greater according to the modified Bell's staging were reviewed.

RESULTS

During the study period, 111 infants developed NEC, and 41/111 (37%) were diagnosed with TANEC. Infants with TANEC were smaller, more premature, had higher SNAPPE scores and were more anemic prior to transfusion compared with infants with 'classic NEC'. The severity of NEC did not differ between the two groups, however, infants with TANEC had worse outcomes and longer NICU stays. Introduction of SSEF protocol, led to a significant decrease in TANEC. There was no difference in weight and head circumference of infants in the two groups at 2 years corrected age.

CONCLUSION

SSEF led to a significant reduction in the incidence of TANEC without impairing growth at 2 years corrected age.

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.

Retrospective case-control study of necrotizing enterocolitis and packed red blood cell transfusions in very low birth weight infants

OBJECTIVE

The study objective was to explore the relationship between necrotizing enterocolitis (NEC) and packed red blood cell (pRBC) transfusion in very low birth weight (VLBW) neonates (<1500 g).

STUDY DESIGN

A six-year retrospective chart review of VLBW infants with NEC (Bell's Stage > II) and a pRBC transfusion within 48 hours of diagnosis. Prenatal data, postnatal course, transfusion history, and NEC outcomes were reviewed. The transfusion associated necrotizing enterocolitis (TANEC) cases were matched with controls (1:2) who were transfused but did not develop NEC as to proximity of birth date, gestational age, and receipt of transfusion.

RESULTS

Of 1139 VLBW admissions, there were 73 cases of NEC and 30 cases of TANEC (annual NEC rate 6.4%). TANEC cases were matched with 60 controls who were transfused but never developed NEC. Neonatal profiles were similar between all 3 groups, except for a higher proportion of infants <10th percentile in the non-TANEC group. Days of antibiotics and frequency of patient ductus arteriosus (PDA) ligation were lower in controls compared to NEC cases. Lower feeding rate at diagnosis of NEC/match were more common in control infants compared to TANEC infants. However, feeding abstinence rates were similar between the two groups. The number of transfusions prior to diagnosis/match was similar in all groups. There was no significant difference in pre-transfusion hematocrit values between the groups.

CONCLUSION

TANEC was common among NEC cases. PDA ligation was similar among TANEC and non-TANEC but lower in controls. Similar pre-transfusion hematocrits were found among TANEC and controls. Feeding abstinence rates were also similar between TANEC and controls.

Splanchnic-Cerebral Oxygenation Ratio Decreases during Enteral Feedings in Anemic Preterm Infants: Observations under Near-Infrared Spectroscopy

BACKGROUND

Anemia is common in premature infants. Due to risks with red blood cell transfusions, many anemic infants are not transfused. The implications of this pathophysiologic status, especially at times of increased metabolic demand (enteral feedings), is not well understood. Near-infrared spectroscopy (NIRS) allows for the noninvasive determination of regional oxygen saturations (rSO2) in tissues such as the brain and mesentery, giving insight into their oxygen sufficiency.

OBJECTIVE

We tested the hypothesis that during enteral feedings very low birth weight (VLBW) infants with a hematocrit ≤28% will experience a decrease in splanchnic rSO2 and splanchnic-cerebral oxygenation ratio (SCOR).

METHODS

This prospective, observational, 2-centered study included VLBW infants receiving full enteral feedings with a hematocrit ≤28%. Cerebral and splanchnic rSO2 were monitored via NIRS for 24 h. Average values were calculated for periods immediately preceding, during, and after each feeding. SCOR was calculated from these values (rSO2 splanchnic/rSO2 cerebral), and data were analyzed using a linear mixed effect model.

RESULTS

Fifty neonates with a median gestational age of 28 weeks (range 23-32), a birth weight of 1,118 ± 284 g (mean ± SD), and a hematocrit of 26 ± 2% (mean ± SD) were studied. During feedings, SCOR decreased significantly from baseline (0.72 ± 0.17 to 0.69 ± 0.17, p = 0.043). With feedings, there was a trend of decreased splanchnic rSO2 (47 ± 11 to 45 ± 10, p = 0.057) and no change in cerebral rSO2 (66 ± 8 to 66 ± 7, p = 0.597).

CONCLUSIONS

VLBW infants with a hematocrit ≤28% had a decrease in SCOR and a trend towards decreased splanchnic rSO2 with enteral feedings.

Expert consensus to weight an adherence score for audit and feedback of practices that prevent necrotizing enterocolitis in very low birth weight infants

OBJECTIVE

Necrotizing enterocolitis (NEC) is a catastrophic abdominal complication threatening the life of premature infants, but adoption of prevention and early recognition practices differs as do NEC rates in Neonatal Intensive Care Units (NICUs). The purpose of this research was to validate and weight an evidence-based adherence score (aka NEC-Zero Adherence Score) to prevent and foster timely recognition of NEC.

STUDY DESIGN

An electronic Delphi (e-Delphi) approach was used to identify consensus. NEC experts were recruited via the NEC Society and surveyed until consensus and stability criteria for the Delphi were met (≥70% consensus and mean responses changed <15% between rounds).

RESULTS

Expert panelists (n=22) were experienced (M=17.6, SD 11years) and predominately physicians (68%) or neonatal nurse practitioners (18%). Consensus (>70% by item) supported a 10 point score. Points were distributed across 1) an exclusive human milk diet (5 points), 2) standardized feeding protocols (3 points), 3) antibiotic stewardship (1 point), and 4) a unit-specified approach to early recognition (1 point). Withholding feeding during transfusion was controversial (M=0.50, SD 0.73) and met consensus criteria to drop from the score.

CONCLUSIONS

Holding feeding during transfusion was dropped from the score. Relationships between the score and unit NEC rates as well as its utility for use in audit and feedback should be studied in the future.

Withholding Feeds and Transfusion-Associated Necrotizing Enterocolitis in Preterm Infants: A Systematic Review

Limited evidence exists to support the withholding of feeds during packed red blood cell (PRBC) transfusion to reduce the incidence of transfusion-associated necrotizing enterocolitis (TANEC) in preterm infants. The aim of the manuscript was to systematically review studies reporting the effect of implementing a policy of withholding feeds on the incidence of TANEC in preterm infants. The following databases were searched for relevant studies published between the databases' inception and December 2016: PubMed, Embase, the Cochrane Central Register of Controlled Trials, the Cumulative Index of Nursing and Allied Health Literature, and Pediatric Academic Societies Abstract Archive. Other relevant sources were also searched. There were no restrictions on study design. Studies reporting on the incidence of TANEC (stage ≥2 necrotizing enterocolitis within 48-72 h) after implementation of a policy of withholding feeds in the peritransfusion period in preterm infants were included. This meta-analysis used a random-effects model with assessment of quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. There were no randomized controlled trials (RCTs). Pooled results from 7 non-RCTs (n = 7492) showed that withholding feeds during PRBC transfusion significantly reduced the incidence of TANEC (RR: 0.47; 95% CI: 0.28, 0.80; P = 0.005; I2 = 11%). The overall quality of evidence was moderate on GRADE analysis. These findings suggest that withholding feeds during the peritransfusion period may reduce the risk of TANEC in preterm infants. Adequately powered RCTs are needed to confirm these findings.

Reducing Incidence of Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a multifactorial disease that occurs when multiple risk factors and/or stressors overlap, leading to profound inflammation and intestinal injury. Due to its multifactorial nature, there has been much uncertainty in identifying clear strategies for prevention of NEC. Despite these obstacles, the incidence of NEC has gradually been decreasing over the past 10 years, in part due to quality improvement (QI) initiatives to prevent NEC. Current QI strategies primarily target the various predisposing conditions. This article reviews the evidence on which QI interventions to prevent NEC have been based and provides examples of successful QI interventions.

The relationship of red blood cell transfusion to intestinal mucosal injury in premature infants

OBJECTIVE

To determine the incidence of intestinal mucosal injury before and after transfusions in premature infants.

STUDY DESIGN

Urine was collected throughout the hospital stay of 62 premature infants and specimens obtained within 24h before and after transfusion were assayed for intestinal fatty acid binding protein (iFABP). A urinary iFABP:creatinine ratio (iFABP_u:Cr_u) of 2.0pg/nmol was considered elevated.

RESULT

Forty-nine infants were transfused. iFABPu:Cru was elevated following 71 (75.6%) of 94 transfusions for which urine was available. In 51 (71.8%) of these, iFABPu:Cru was also elevated prior to the transfusion. Among four cases of transfusion-associated NEC, iFABP_u was elevated following every sentinel transfusion and prior to three of them.

CONCLUSION

Subclinical intestinal mucosal injury is frequent following blood transfusions in premature infants and, when present, usually precedes transfusion. This suggests that transfusion may not be a primary mediator of intestinal injury so much as anemia and its associated conditions.

LEVEL OF EVIDENCE

Prognosis study/level 3.

Red blood cell transfusions can induce proinflammatory cytokines in preterm infants

BACKGROUND

The risk of developing red blood cell (RBC) transfusion-associated necrotizing enterocolitis (TANEC) in preterm infants has recently been emphasized. Our aim was to assess changes in cytokine serum levels after RBC transfusions in a cohort of very preterm infants to evaluate their possible proinflammatory effect.

STUDY DESIGN AND METHODS

We carried out a prospective observational study. One transfusion event was studied in infants less than 32 weeks' gestation and more than 7 days old (n = 20) admitted to a tertiary neonatal intensive care unit. Interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor-α, interferon-γ (IFN-γ), IL-17, monocyte chemoattractant protein-1 (MCP-1), interferon-γ-induced protein 10 (IP-10), intracellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule serum levels were measured in enrolled patients within 120 minutes before (T₀ ) the RBC transfusion and then within 120 minutes (T₁ ), 12 ± 3 hours (T₂ ), 24 ± 6 hours (T₃ ), and 48 ± 6 hours (T₄ ) after the end of RBC transfusion.

RESULTS

Infants received 19.8 ± 3.0 mL of RBCs at the mean age of 50 ± 18 days. Their hematocrit level increased from 24.1 ± 1.2% to 39.4 ± 2.9%. IL-1β, IL-8, IFN-γ, IL-17, MCP-1, IP-10, and ICAM-1 increased significantly after RBC transfusions.

CONCLUSION

Proinflammatory cytokines are increased after RBC transfusion. These findings may contribute to explaining the pathogenesis of TANEC and suggest the opportunity of adopting wise transfusion guidelines that would help to avoid detrimental risks of transfusion-related immunomodulation and of undertransfusion.

Should we believe in transfusion-associated enterocolitis? Applying a GRADE to the literature

Numerous observational studies appear to demonstrate an association between packed red blood cell (pRBC) transfusions and necrotizing enterocolitis (NEC). However, the limited numbers of randomized controlled trials (RCTs) do not support a causal relationship between pRBC transfusion and NEC. We sought to determine the quality of the evidence behind transfusion-associated necrotizing enterocolitis (TANEC), and to formulate a GRADE-based recommendation regarding transfusion practices to reduce the risk of TANEC. A systematic search including MEDLINE, Embase, CINAHL, the Cochrane Central Register of Controlled Trials and clinical trials registries was performed for studies assessing the association between transfusion and NEC. Teams of two paired reviewers independently screened studies for eligibility, assessed risk of bias using the GRADE framework, and collected data from each eligible study. We examined studies for two time points following transfusion: within 48h if this was available, and otherwise at any time after transfusion. In total, 23 observational studies and three RCTs met inclusion criteria. The average rating for the quality of evidence of individual studies was between "very low" and "low." On pooling studies for GRADE review, we observed an inconsistency of results. This led to a final overall quality of "very low" for the evidence for an association between transfusions and necrotizing enterocolitis. The pooled outcome of NEC for observational/case control studies was an odds ratio of 1.13 (95% CI: 0.99-1.29) when TANEC was defined as occurring within 48 hours of transfusion. For NEC occurring at any time post-transfusion, the pooled OR was 1.95 (1.60-2.38). Conversely, the pooled outcome of NEC for the RCT data had an odds ratio of 0.6 (0.3, 1.21) with NEC being less frequent in the liberal transfusion group compared to the restrictive transfusion group. The overall quality of the evidence for TANEC is "very low," suggesting very little confidence in the effect estimate. RCT data tended toward apparent protection against NEC. The available evidence is not sufficient to support a practice recommendation around pRBC transfusions in the context of preventing the development of NEC.

Transfusion reactions: prevention, diagnosis, and treatment

Blood transfusion is one of the most common procedures in patients in hospital so it is imperative that clinicians are knowledgeable about appropriate blood product administration, as well as the signs, symptoms, and management of transfusion reactions. In this Review, we, an international panel, provide a synopsis of the pathophysiology, treatment, and management of each diagnostic category of transfusion reaction using evidence-based recommendations whenever available.