Association of packed red blood cell transfusion and necrotizing enterocolitis in very low birth weight infants

Severe anemia predisposes very premature infants to transfusion-associated necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a catastrophic inflammatory bowel necrosis of premature infants. The etiology is unknown, but 25-40 % of cases have a history of red blood cell (RBC) transfusions in the preceding 48 h. This association has been noted in retrospective case/case-control studies, and many meta-analyses, and in a murine model. However, we still need human studies with larger, adequately powered cohorts to confirm this association and determine the operant mechanisms. The murine model shows that severe anemia leads to macrophage infiltration in the gut mucosa. Subsequent RBC transfusions containing free hemoglobin, activate nuclear factor-kappa B-mediated inflammatory changes and cause NEC-like mucosal injury. This review summarizes current human and experimental data to evaluate ta-NEC and hitherto unanswered mechanistic questions. If a causal relationship between transfusions and NEC is proven, these data could help develop effective therapeutic strategies.

Apnea of Prematurity and Oxidative Stress: Potential Implications

Apnea of prematurity (AOP) occurs in 85% of neonates ≤34 weeks of gestational age. AOP is frequently associated with intermittent hypoxia (IH). This narrative review reports on the putative relationship of AOP with IH and the resulting oxidative stress (OS). Preterm infants are susceptible to OS due to an imbalance between oxidant and antioxidant systems with the excessive free radical load leading to serious morbidities that may include retinopathy of prematurity, bronchopulmonary dysplasia, and neurodevelopmental delay. Current therapeutic approaches to minimize the adverse effects of AOP and optimize oxygen delivery include noninvasive ventilation and xanthine inhibitor therapy, but these approaches have only been partially successful in decreasing the incidence of AOP and associated morbidities.

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.

Risk factors for necrotizing enterocolitis in preterm infants: a Meta analysis

OBJECTIVES

To systematically evaluate the risk factors for necrotizing enterocolitis (NEC) in preterm infants.

METHODS

PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, and Wanfang Data were searched for case-control studies and cohort studies on the risk factors for NEC in preterm infants published up to December 2021. RevMan 5.3 software was used to perform the Meta analysis.

RESULTS

A total of 38 studies were included (28 case-control studies and 10 cohort studies). The Meta analysis showed that maternal gestational diabetes (OR=2.96, P<0.001), intrahepatic cholestasis during pregnancy (OR=2.53, P<0.001), preeclampsia (OR=1.73, P=0.020), history of neonatal asphyxia (OR=2.13, P<0.001), low gestational age (OR=1.23, P=0.010), sepsis (OR=5.32, P<0.001), patent ductus arteriosus (OR=1.57, P=0.001), congenital heart disease (OR=3.78, P<0.001), mechanical ventilation (OR=2.23, P=0.020), history of antibiotic use (OR=1.07, P<0.001), use of vasopressors (OR=2.34, P=0.040), and fasting (OR=1.08, P<0.001) were risk factors for NEC in preterm infants, while cesarean section (OR=0.73, P=0.004), use of pulmonary surfactant (OR=0.43, P=0.008), and breastfeeding (OR=0.24, P=0.020) were protective factors against NEC.

CONCLUSIONS

Maternal gestational diabetes, intrahepatic cholestasis during pregnancy, preeclampsia, low gestational age, fasting, sepsis, patent ductus arteriosus, congenital heart disease, and histories of asphyxia, mechanical ventilation, antibiotic use, and use of vasopressors may increase the risk of NEC in preterm infants, while cesarean section, use of pulmonary surfactant, and breastfeeding may decrease the risk of NEC in preterm infants.

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.

Feeding Practices and Effects on Transfusion-Associated Necrotizing Enterocolitis in Premature Neonates

BACKGROUND

Red blood cell (RBC) transfusions have been implicated in the development of necrotizing enterocolitis (NEC) in premature infants. Some evidence exists to support that withholding feedings during transfusion reduces the risk of subsequent NEC development.

PURPOSE

To review the most recent literature on this topic to determine best evidence-based practice regarding withholding or not withholding feedings during RBC transfusions.

METHODS/SEARCH STRATEGY

Four databases were searched using keywords and MeSH terms including "necrotizing enterocolitis," "NEC," "NPO," and "transfusion," with specifications limiting the search to articles published in the last 10 years and limiting the population to neonates.

FINDINGS

Four studies did not demonstrate a reduction in transfusion-associated necrotizing enterocolitis (TANEC) with the implementation of feeding protocols during packed red blood cell (PRBC) transfusions. One study concluded that it could not confirm the benefit of withholding feeds during transfusion to reduce the risk of TANEC. A 2020 randomized controlled trial (RCT) found no difference in splanchnic oxygenation when enteral feeds are withheld, continued, or restricted during a PRBC transfusion. Holding feedings during PRBC transfusions did not result in adverse nutritional outcomes.

IMPLICATIONS FOR PRACTICE

To determine best evidence-based practice surrounding feeding protocols during RBC transfusions in very low-birth-weight and premature infants less than 37 weeks' gestation.

IMPLICATIONS FOR RESEARCH

It is recommended that large, multicentered, adequately powered RCTs be conducted in this area. Individual institutions should standardize their practice to improve quality, safety, and patient outcomes.

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.

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.

New insights into necrotizing enterocolitis: From laboratory observation to personalized prevention and treatment

BACKGROUND/PURPOSE

Necrotizing enterocolitis (NEC) is a devastating disease of prematurity that develops after feeding, often without warning, and results in diffuse intestinal necrosis leading to sepsis and death in many cases. The lack of improvement in overall survival is influenced by nonspecific diagnostic modalities as well as inexact and nonpersonalized treatment strategies.

METHODS/RESULTS

Recently, we and others have shown that NEC develops in response to exaggerated bacterial signaling in the premature intestine, as a consequence of elevated expression and activity of the bacterial receptor toll-like receptor 4 (TLR4), which is important for normal gut development. Breast milk is a powerful TLR4 inhibitor, while mutations in TLR4 genes lead to increased NEC risk in humans, providing proof-of-concept for its role in NEC. Recently, a drug discovery approach has revealed a novel class of TLR4 inhibitors which are being developed for personalized approaches to NEC treatment.

CONCLUSION

This review will highlight the current understanding of the role of bacterial signaling in NEC pathogenesis, and will describe advances in diagnosis, prevention and treatment of NEC that may hopefully improve survival for these most fragile patients.

SYSTEMATIC REVIEW

Level of Evidence: Level II.

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.

Pathophysiology of Necrotizing Enterocolitis: An Update

NEC is a devastating disease that, once present, is very difficult to treat. In the absence of an etiologic treatment, preventive measures are required. Advances in decoding the pathophysiology of NEC are being made but a more comprehensive understanding is needed for the targeting of preventative strategies. A better definition of the disease as well as diagnostic criteria are needed to be able to specifically label a disease as NEC. Multiple environmental factors combined with host susceptibility appear to contribute to enhanced risks for developing this disease. Several different proximal pathways are involved, all leading to a common undesired outcome: Intestinal necrosis. The most common form of this disease appears to involve inflammatory pathways that are closely meshed with the intestinal microbiota, where a dysbiosis may result in dysregulated inflammation. The organisms present in the intestinal tract prior to the onset of NEC along with their diversity and functional capabilities are just beginning to be understood. Fulfillment of postulates that support causality for particular microorganisms is needed if bacteriotherapies are to be intelligently applied for the prevention of NEC. Identification of molecular effector pathways that propagate inflammation, understanding of, even incipient role of genetic predisposition and of miRNAs may help solve the puzzle of this disease and may bring the researchers closer to finding a treatment. Despite recent progress, multiple limitations of the current animal models, difficulties related to studies in humans, along with the lack of a "clear" definition will continue to make it a very challenging disease to decipher.

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-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.

Indications for red cell transfusions in pediatric patients

Red cell transfusions are amongst the most common therapeutic procedures in seriously ill children, particularly in the inpatient setting. This is despite the fact that there is no evidence base for most clinical settings, with the exception of patients with hemoglobinopathies, particularly thalassemia and sickle cell anemia. Obviously exsanguinating hemorrhage and life threatening anemia are urgent indications for which no other therapeutic approach is currently available. Most transfusions are, however, given prophylactically to prevent the complications of hypoxia or hemodynamic stability, based upon expert opinion and a faith in the oxygen carrying capacity and beneficial hemodynamic properties of transfused red cells. The question confronting current day pediatric practice is to what extent transfused red cells prevent adverse events, other than in thalassemia and sickle cell anemia, as opposed to causing them. Do transfusions of red cells prevent organ failure, stroke, etc. or not? There is epidemiologic evidence in the adult randomized trial literature that liberal red cell transfusion likely causes more such adverse events than it prevents. The relevance of such studies to children, particularly neonates, is uncertain. Randomized trials in critically ill neonates have yielded little to no evidence that liberal red cell transfusion is beneficial, but the data are not definitive. In critically ill older children the data suggest there is no benefit to liberal red cell transfusion, but the indications for red cell transfusion are uncertain. Most practitioners would agree that combining laboratory data such hemoglobin/hematocrit with clinical indications for transfusions (evidence of end organ hypoxia such as tachycardia, shortness of breath, etc.) is the only viable strategy at present, until more definitive randomized trial data are available.

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."

Red blood cell transfusion in premature infants leads to worse necrotizing enterocolitis outcomes

BACKGROUND

Necrotizing enterocolitis (NEC) is a severe intestinal disease of premature infants with high mortality. Studies suggest a causative relationship between red blood cell (RBC) transfusion and NEC; however, whether RBC transfusion leads to worse outcomes in NEC is unknown. We sought to determine whether RBC transfusion was associated with an increased risk of surgical NEC and mortality.

METHODS

In this retrospective study, 115 patients were enrolled with NEC Bell's stage 2A or greater from 2010-2015. Patients were classified based on the timing of RBC transfusion before NEC: ≤72 h, >72 h, and no transfusion. Variables including gestational age (GA), birth weight (BW), feedings, and hematocrit levels were analyzed. Outcomes were surgical intervention for NEC following RBC transfusion and mortality.

RESULTS

Twenty-three (20%) infants developed NEC ≤ 72 h after RBC transfusion, 16 (69.6%) required surgery with a mortality rate of 21.7% (n = 5). Seventeen (15%) infants developed NEC > 72 h after RBC transfusion, 12 (70.6%) required surgery with a mortality rate of 23.5% (n = 4). 75 (65%) patients developed NEC without RBC transfusion, 17 (22.7%) required surgery with a mortality rate of 4% (n = 3). Lower GA and BW were significantly associated with RBC transfusion and the need for surgical intervention. RBC transfusion ≤72 h before NEC was associated with surgical NEC (pairwise adjusted P < 0.001) and mortality (pairwise adjusted P = 0.048). However, multivariable logistic regression analysis revealed RBC transfusion is not an independent risk factor for surgical NEC.

CONCLUSIONS

Infants of lower GA and BW were more likely to receive an RBC transfusion before NEC, which was significantly associated with surgical intervention and an increasing risk of mortality. Judicious use of transfusions in premature infants may improve NEC outcomes.

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.

Barriers to Knowledge Translation Regarding the Use of Probiotics as a Risk-Reduction Strategy for Necrotizing Enterocolitis

BACKGROUND

Increasingly, evidence supports enteral probiotics are an important risk-reduction strategy for necrotizing enterocolitis (NEC) among very low birth-weight and extremely low birth-weight preterm infants. Yet, the majority of providers remain reluctant to implement practice changes.

PURPOSE

The aim of this study was to better understand the discrepancy between the available evidence and clinical practice regarding the use of probiotics and other NEC prevention strategies in New Jersey.

METHODS

Using an exploratory descriptive design, a multimodal interprofessional survey was developed and executed to elicit intensive care nursery provider knowledge, views, and current practice.

RESULTS

Although the sample size was small (N = 29), approximately one-half of respondents familiar with the literature rated the quality of the evidence regarding probiotics as "above average" to "excellent." These respondents were "very likely" to "extremely likely" to recommend probiotics as an NEC prevention strategy; however, none actually prescribed this intervention. The most important reason respondents did not prescribe probiotics was the focus on providing exclusive maternal and donor breast milk feedings. Other confounding factors included provision of oral colostrum care, standardized feeding protocols, and withholding feedings during blood transfusion.

IMPLICATIONS FOR PRACTICE

Study results suggested that some providers (primarily nurses) were not familiar with probiotic literature, which may contribute to deficits in knowledge translation to practice.

IMPLICATIONS FOR RESEARCH

Areas for future study include identifying improved mechanisms for knowledge dissemination, recognizing and addressing barriers and facilitators to knowledge translation, and understanding how probiotics fit and/or contrast with other NEC risk-reduction strategies in the research and clinical settings.

Etiology and medical management of NEC

Necrotising enterocolitis (NEC) is a serious infection of the bowel that predominantly affects preterm infants and is a leading cause for mortality and morbidity in preterm infants. It involves a spectrum of pathology including widespread inflammation of the intestinal mucosa, invasion of the immature gut by enteric gas forming bacteria, dissection of the gut wall and portal veins by this gas, often culminating in ischemic necrosis of the intestine. This article provides an overview of the incidence, etio-pathological risk factors, preventive strategies and medical management of NEC.

Association of Red Blood Cell Transfusion, Anemia, and Necrotizing Enterocolitis in Very Low-Birth-Weight Infants

IMPORTANCE

Data regarding the contribution of red blood cell (RBC) transfusion and anemia to necrotizing enterocolitis (NEC) are conflicting. These associations have not been prospectively evaluated, accounting for repeated, time-varying exposures.

OBJECTIVE

To determine the relationship between RBC transfusion, severe anemia, and NEC.

DESIGN, SETTING, AND PARTICIPANTS

In a secondary, prospective, multicenter observational cohort study from January 2010 to February 2014, very low-birth-weight (VLBW, ≤1500 g) infants, within 5 days of birth, were enrolled at 3 level III neonatal intensive care units in Atlanta, Georgia. Two hospitals were academically affiliated and 1 was a community hospital. Infants received follow-up until 90 days, hospital discharge, transfer to a non-study-affiliated hospital, or death (whichever came first). Multivariable competing-risks Cox regression was used, including adjustment for birth weight, center, breastfeeding, illness severity, and duration of initial antibiotic treatment, to evaluate the association between RBC transfusion, severe anemia, and NEC.

EXPOSURES

The primary exposure was RBC transfusion. The secondary exposure was severe anemia, defined a priori as a hemoglobin level of 8 g/dL or less. Both exposures were evaluated as time-varying covariates at weekly intervals.

MAIN OUTCOMES AND MEASURES

Necrotizing enterocolitis, defined as Bell stage 2 or greater by preplanned adjudication. Mortality was evaluated as a competing risk.

RESULTS

Of 600 VLBW infants enrolled, 598 were evaluated. Forty-four (7.4%) infants developed NEC. Thirty-two (5.4%) infants died (all cause). Fifty-three percent of infants (319) received a total of 1430 RBC transfusion exposures. The unadjusted cumulative incidence of NEC at week 8 among RBC transfusion-exposed infants was 9.9% (95% CI, 6.9%-14.2%) vs 4.6% (95% CI, 2.6%-8.0%) among those who were unexposed. In multivariable analysis, RBC transfusion in a given week was not significantly related to the rate of NEC (adjusted cause-specific hazard ratio, 0.44 [95% CI, 0.17-1.12]; P = .09). Based on evaluation of 4565 longitudinal measurements of hemoglobin (median, 7 per infant), the rate of NEC was significantly increased among VLBW infants with severe anemia in a given week compared with those who did not have severe anemia (adjusted cause-specific hazard ratio, 5.99 [95% CI, 2.00-18.0]; P = .001).

CONCLUSIONS AND RELEVANCE

Among VLBW infants, severe anemia, but not RBC transfusion, was associated with an increased risk of NEC. Further studies are needed to evaluate whether preventing severe anemia is more important than minimizing RBC transfusion.

Late Presentation of Fulminant Necrotizing Enterocolitis in a Child with Hyperinsulinism on Octreotide Therapy

Congenital hyperinsulinism (HI) is the most common cause of persistent hypoglycemia in infants and children. In cases of diazoxide-unresponsive HI, alternative medical and surgical approaches may be required to reduce the risk of hypoglycemia. Octreotide, a somatostatin analog, often has a role in the management of these children, but a dose-dependent reduction in splanchnic blood flow is a recognized complication. Necrotizing enterocolitis (NEC) has been reported within the first few weeks of initiating predominantly high doses of octreotide. We describe the case of an infant with Beckwith-Wiedemann syndrome and diazoxide-unresponsive HI, who had persistent hypoglycemia after two pancreatectomy surgeries. She developed NEC 2 months after beginning octreotide therapy at a relatively low dose of 8 µg/kg/day. This complication has occurred later, and at a lower dose, than has previously been described. We review the case and identify the known and suspected multifactorial risk factors for NEC that may contribute to the development of this complication in patients with HI.

Broad-spectrum Antibiotic Plus Metronidazole May Not Prevent the Deterioration of Necrotizing Enterocolitis From Stage II to III in Full-term and Near-term Infants: A Propensity Score-matched Cohort Study

Necrotizing enterocolitis (NEC) is the most common and frequently dangerous neonatal gastrointestinal disease. Studies have shown broad-spectrum antibiotics plus anaerobic antimicrobial therapy did not prevent the deterioration of NEC among very low birth preterm infants. However, few studies about this therapy which focused on full-term and near-term infant with NEC has been reported. The aim of this study was to evaluate the effect of broad-spectrum antibiotic plus metronidazole in preventing the deterioration of NEC from stage II to III in full-term and near-term infants.A retrospective cohort study based on the propensity score (PS) 1:1 matching was performed among the full-term and near-term infants with NEC (Bell stage ≥II). All infants who received broad-spectrum antibiotics were divided into 2 groups: group with metronidazole treatment (metronidazole was used ≥4 days continuously, 15 mg/kg/day) and group without metronidazole treatment. The depraved rates of stage II NEC between the 2 groups were compared. Meanwhile, the risk factors associated with the deterioration of stage II NEC were analyzed by case-control study in the PS-matched cases.A total of 229 infants met the inclusion criteria. Before PS-matching, we found the deterioration of NEC rate in the group with metronidazole treatment was higher than that in the group without metronidazole treatment (18.1% [28/155] vs 8.1% [6/74]; P = 0.048). After PS-matching, 73 pairs were matched, and the depraved rate of NEC in the group with metronidazole treatment was not lower than that in the group without metronidazole treatment (15.1% vs 8.2%; P = 0.2). Binary logistic regression analysis showed that sepsis after NEC (odds ratio [OR] 3.748, 95% confidence interval [CI] 1.171-11.998, P = 0.03), the need to use transfusion of blood products after diagnosis of NEC (OR 8.003, 95% CI 2.365-27.087, P = 0.00), and the need of longer time for nasogastric suction were risk factors for stage II NEC progressing to stage III (OR 1.102, 95% CI 1.004-1.21, P = 0.04).Broad-spectrum antibiotic plus metronidazole may not prevent the deterioration of NEC in full-term and near-term infants. Those infants who had sepsis required transfusion of blood products, and needed longer time for nasogastric suction after stage II NEC was more likely to progress to stage III.

Evaluation of caffeine and the development of necrotizing enterocolitis

OBJECTIVE

To test the association between medical or surgical necrotizing enterocolitis (NEC) and caffeine administration in premature infants.

STUDY DESIGN

This single-center, retrospective study evaluated patients admitted to a level 3 neonatal intensive care unit (NICU) over an 18-month period. All patients were evaluated for factors associated with the development of NEC including exposure to caffeine (dosing and duration), gestational age, birth weight, vasoactive medications and maternal illicit drug use.

RESULTS

There were 615 subjects included in the study; among these subjects, 7.3% (n = 45) developed NEC (35 subjects receiving caffeine and 10 subjects not receiving caffeine). The administration of caffeine (p = 0.008), birth weight (p = 0.014) and the use of vasopressors (p = 0.033) were associated with the development of NEC. When considering only infants with a birth weight less than 1500 g and less than 32 weeks gestation, the effects of caffeine and vasopressor use remained statistically significant (p = 0.047 and p = 0.045, respectively). The time to development of NEC did not differ statistically between patients receiving caffeine and those not receiving caffeine (p = 0.129).

CONCLUSION

A potential association between the administration of caffeine and the development of medical or surgical necrotizing enterocolitis in premature infants exists. Further investigation of dose-dependent effects and loading doses is warranted.