Necrotizing enterocolitis in neonates with symptomatic congenital heart disease

Risk Factors for Adverse Outcomes in Term Infants with CHD and Definitive Necrotising Enterocolitis

OBJECTIVES

To define the incidence of definitive necrotising enterocolitis in term infants with CHD and identify risk factors for morbidity/mortality.

METHODS

We performed a 20-year (2000-2020) single-institution retrospective cohort study of term infants with CHD admitted to the Boston Children's Hospital cardiac ICU with necrotising enterocolitis (Bell's stage ≥ II). The primary outcome was a composite of in-hospital mortality and post-necrotising enterocolitis morbidity (need for extracorporeal membrane oxygenation, multisystem organ failure based on the paediatric sequential organ failure assessment score, and/or need for acute gastrointestinal intervention). Predictors included patient characteristics, cardiac diagnosis/interventions, feeding regimen, and severity measures.

RESULTS

Of 3933 term infants with CHD, 2.1% (n = 82) developed necrotising enterocolitis, with 67% diagnosed post-cardiac intervention. Thirty (37%) met criteria for the primary outcome. In-hospital mortality occurred in 14 infants (17%), of which nine (11%) deaths were attributable to necrotising enterocolitis. Independent predictors of the primary outcome included moderate to severe systolic ventricular dysfunction (odds ratio 13.4,confidence intervals 1.13-159) and central line infections pre-necrotising enterocolitis diagnosis (odds ratio 17.7, confidence intervals 3.21-97.0) and mechanical ventilation post-necrotising enterocolitis diagnosis (odds ratio 13.5, confidence intervals 3.34-54.4). Single ventricle, ductal dependency, and feeding related factors were not independently associated with the primary outcome.

CONCLUSIONS

The incidence of necrotising enterocolitis was 2.1% in term infants with CHD. Adverse outcomes occurred in greater than 30% of patients. Presence of systolic dysfunction and central line infections prior to diagnosis and need for mechanical ventilation after diagnosis of necrotising enterocolitis can inform risk triage and prognostic counseling for families.

Clinical Characteristics and Potential Pathogenesis of Cardiac Necrotizing Enterocolitis in Neonates with Congenital Heart Disease: A Narrative Review

Neonates with congenital heart disease (CHD) are at an increased risk of developing necrotizing enterocolitis (NEC), an acute inflammatory intestinal injury most commonly associated with preterm infants. The rarity of this complex disease, termed cardiac NEC, has resulted in a dearth of information on its pathophysiology. However, a higher incidence in term infants, effects on more distal regions of the intestine, and potentially a differential immune response may distinguish cardiac NEC as a distinct condition from the more common preterm, classical NEC. In this review, risk factors, differentiated from those of classical NEC, are discussed according to their potential contribution to the disease process, and a general pathogenesis is postulated for cardiac NEC. Additionally, biomarkers specific to cardiac NEC, clinical outcomes, and strategies for achieving enteral feeds are discussed. Working towards an understanding of the mechanisms underlying cardiac NEC may aid in future diagnosis of the condition and provide potential therapeutic targets.

Human Milk Use in the Preoperative Period Is Associated with a Lower Risk for Necrotizing Enterocolitis in Neonates with Complex Congenital Heart Disease

OBJECTIVE

To evaluate the hypothesis that feeding volumes exceeding 100 mL/kg/d and exposure to cow's milk formula preoperatively increase the risk for preoperative necrotizing enterocolitis (NEC) in infants with complex congenital heart disease.

STUDY DESIGN

All infants, of any gestational age, with an isolated cardiac lesion at high risk for NEC (ductal-dependent lesions, transposition of the great arteries, truncus arteriosus, and aorto-pulmonary window) admitted to Texas Children's Hospital from 2010 to 2016 were included. NEC was defined based on the modified Bell criteria. Feeding regimen information and relevant covariates were collected. Logistic regression was used to evaluate the association of feeding regimen and other potential risk factors with NEC.

RESULTS

In this single-center, retrospective cohort of 546 infants, 3.3% developed Bell stage I-III NEC preoperatively. An exclusive unfortified human milk diet was associated with a significantly lower risk of preoperative NEC (OR 0.17, 95% CI 0.04-0.84, P = .03) in a multivariable regression model controlling for cardiac lesion, race, feeding volume, birth weight small for gestational age, inotrope use presurgery/pre-NEC, and prematurity. Feeding volumes exceeding 100 mL/kg/d were associated with a significantly greater risk of preoperative NEC (OR 3.05, 95% CI 1.19-7.90, P = .02).

CONCLUSIONS

The findings suggest that an unfortified exclusive human milk diet may reduce the risk of preoperative NEC in infants with complex congenital heart disease.

Necrotizing enterocolitis comes in different forms: Historical perspectives and defining the disease

The specific cause of what is commonly referred to as necrotizing enterocolitis (NEC) disease has been elusive largely because it is becoming clear that this entity represents more than one disease with multifactorial pathogenic mechanisms. Furthermore, finding clear and consistent diagnostic biomarkers will be difficult until the different subsets of what we are calling this disease are better delineated. In this introductory chapter, we discuss different disease entities that are frequently termed "NEC" in the newborn infant. We hope this will set the stage for more focused research and development of preventative measures for at least the most common forms of this disease.

Suspected necrotising enterocolitis after surgery for CHD: an opportunity to improve practice and outcomes

Infants with CHD are at increased risk of necrotising enterocolitis, which can interfere with the achievement of adequate nutrition and, ultimately, growth and development. Necrotising enterocolitis is classified by severity as suspected, confirmed, and advanced. We sought to quantify the incidence of all types of necrotising enterocolitis among infants who underwent surgery, with a particular focus on suspected necrotising enterocolitis. This is a retrospective review of all infants <6 months of age who underwent cardiac surgery during 2012 and 2013 at Children's Hospital Colorado. We examined the hospital course of 265 hospitalisations (n=251 patients) and found 18 patients (19 hospitalisations) with suspected necrotising enterocolitis and 16 patients (16 hospitalisations) with confirmed or advanced necrotising enterocolitis. Single-ventricle physiology, lower weight, and younger age were associated with necrotising enterocolitis. Patients with all types of necrotising enterocolitis experienced prolonged length of hospital stay. We found suspected necrotising enterocolitis to be as common as confirmed necrotising enterocolitis, and it frequently occurred early in the post-operative course. We speculate that suspected necrotising enterocolitis may often be overlooked in research owing to a reliance on billing codes. Nevertheless, suspected necrotising enterocolitis poses a substantial barrier to post-operative progression of the CHD patient, as does confirmed necrotising enterocolitis. Following the diagnosis of all types of necrotising enterocolitis, there was wide variability in practice patterns. In response to this variability, we developed care guidelines for the diagnosis and treatment of necrotising enterocolitis in this population.

Cardiopulmonary Resuscitation in Infants and Children With Cardiac Disease: A Scientific Statement From the American Heart Association

Cardiac arrest occurs at a higher rate in children with heart disease than in healthy children. Pediatric basic life support and advanced life support guidelines focus on delivering high-quality resuscitation in children with normal hearts. The complexity and variability in pediatric heart disease pose unique challenges during resuscitation. A writing group appointed by the American Heart Association reviewed the literature addressing resuscitation in children with heart disease. MEDLINE and Google Scholar databases were searched from 1966 to 2015, cross-referencing pediatric heart disease with pertinent resuscitation search terms. The American College of Cardiology/American Heart Association classification of recommendations and levels of evidence for practice guidelines were used. The recommendations in this statement concur with the critical components of the 2015 American Heart Association pediatric basic life support and pediatric advanced life support guidelines and are meant to serve as a resuscitation supplement. This statement is meant for caregivers of children with heart disease in the prehospital and in-hospital settings. Understanding the anatomy and physiology of the high-risk pediatric cardiac population will promote early recognition and treatment of decompensation to prevent cardiac arrest, increase survival from cardiac arrest by providing high-quality resuscitations, and improve outcomes with postresuscitation care.

Noncardiac Challenges in the Cardiac ICU: Feeding, Growth and Gastrointestinal Complications, Anticoagulation, and Analgesia

Outcomes following cardiac intensive care unit (CICU) admission are influenced by many factors including initial cardiac diagnosis, surgical complexity, and burden of critical illness. Additionally, the presence of noncardiac issues may have a significant impact on outcomes and the patient experience during and following an intensive care unit stay. This review focuses on three common noncardiac areas which impact outcomes and patient experience in and beyond the CICU: feeding and growth, pain and analgesia, and anticoagulation. Growth failure and feeding dysfunction are commonly encountered in infants requiring cardiac surgery and have been associated with worse surgical and developmental outcomes. Recent studies most notably in the single ventricle population have demonstrated improved weight gain and outcomes when feeding protocols are implemented. Children undergoing cardiac surgery may experience both acute and chronic pain. Emerging research is investigating the impact of sedatives and analgesics on neurodevelopmental outcomes and quality of life. Improved pain scores and standardized management of pain and withdrawal may improve the patient experience and outcomes. Effective anticoagulation is a critical component of perioperative care but may be complicated by inflammation, multiorgan dysfunction, and patient factors. Advances in monitoring of anticoagulation and emerging therapies are reviewed.

Necrotizing enterocolitis in infants with ductal-dependent congenital heart disease

OBJECTIVE

Infants with congenital heart disease (CHD) receiving prostaglandins (PGEs) may be at an increased risk for necrotizing enterocolitis (NEC). Enteral feeding may further increase the risk of NEC in these patients. We evaluated the incidence of NEC and its association with enteral feeding in infants with ductal-dependent CHD.

STUDY DESIGN

We examined a cohort of infants with CHD receiving PGE in neonatal intensive care units managed by the Pediatrix Medical Group (Sunrise, FL) between 1997 and 2010. We used logistic regression to evaluate the association between NEC and enteral feeding, as well as other risk factors, including antacid medications, inotropic and ventilator support, and anatomic characteristics, controlling for gestational age.

RESULTS

We identified 6,710 infants with ductal-dependent CHD receiving PGE for 17,158 infant days. NEC occurred in 21 of the 6,710 (0.3%) infants, of whom 12/21 (57%) were < 37 weeks gestational age. The incidence of NEC was 1.2/1,000 infant days while on enteral feeds versus 0.4/1,000 infant days while not on enteral feeds (p = 0.27). Enteral feeding was not associated with a statistically significant increased odds of NEC on the day of diagnosis (odds ratio [OR] 2.08; 95% confidence interval [CI] 0.38, 11.7). Risk factors associated with a significant increased odds of NEC included a diagnosis of single-ventricle heart defect (OR 2.82; 95% CI 1.23, 6.49), although the overall risk in this population remained low (8/1,631, 0.5%).

CONCLUSION

The incidence of NEC in our cohort of infants with ductal-dependent CHD on PGE therapy was low and did not increase with enteral feeding.

Necrotizing enterocolitis in infants with congenital heart disease: the role of red blood cell transfusions

Necrotizing enterocolitis (NEC) is a rare but catastrophic complication that may occur in newborns with congenital heart disease (CHD). In the preterm population, transfusion of red blood cells (RBCs) and use of RBCs with longer storage time have been independently associated with the development of NEC. To date, it is not known whether similar associations exist for the term newborn with CHD. This retrospective study identified the incidence of NEC among 1,551 newborns admitted to the authors' cardiac intensive care unit between 7 January 2002 and 7 January 2010. The study was limited to term newborns (>36 weeks gestation). To understand the impact of RBC transfusions on the development of NEC, a nested 2:1 matched case-control analysis was undertaken to compare RBC transfusion patterns between an age-matched group and a cardiac lesion-matched control group. In the study population, NEC developed in 45 term infants during the postoperative period. Of these 45 infants, 30 (66.7%) had single-ventricle heart defects, whereas 22 (48.8%) required surgery for aortic arch obstruction. The median patient age at NEC diagnosis was 21 days. The RBC transfusion rate was higher among the patients who experienced NEC (0.21/day) than among the control subjects (0.10/day) (p = 0.048). A multivariate analysis indicated that onset of NEC was associated with a greater number of RBC transfusions (odds ratio [OR] 1.83; 95% confidence interval [CI] 1.07-7.47; p = 0.045). The duration of RBC storage was not significantly longer in the NEC group (9 days) than in the control cohort (7 days) (p = 0.16). Increased exposure to RBC transfusions is associated with the development of NEC in term infants with CHD. Longer storage of RBCs does not appear to increase this risk. Although causality cannot be confirmed, these data prompt a careful review of RBC transfusion practices with this population.

Intestinal location of necrotizing enterocolitis among infants with congenital heart disease

OBJECTIVE

To determine whether differences exist in the location of necrotizing enterocolitis (NEC) in infants with congenital heart disease (CHD) versus those without CHD.

STUDY DESIGN

Retrospective cohort study utilizing 11 years of patient data. Inclusion criterion was surgical exploration for NEC. Presence or absence of CHD was determined. Surgical and/or pathology reports were reviewed to identify the location of NEC. Data were analyzed by t-tests and χ(2) analyses.

RESULT

One hundred and sixty-seven patients met the inclusion criteria. CHD infants had a higher percentage of mortality. There was no difference in the location of NEC between non-CHD and CHD patients, with the predominant location being the small intestine in both. In addition, there was no difference in the location of NEC between preterm non-CHD patients and full-term CHD patients with the small intestine again being the primary site.

CONCLUSION

Despite differences in gestational age between non-CHD and CHD patients, the location of NEC in these infants did not differ.

Probiotic administration in congenital heart disease: a pilot study

OBJECTIVE

To investigate the impact of probiotic Bifidobacterium longum ssp. infantis on the fecal microbiota and plasma cytokines in neonates with congenital heart disease.

STUDY DESIGN

Sixteen infants with congenital heart disease were randomly assigned to receive either B. infantis (4.2 × 10(9) colony-forming units two times daily) or placebo for 8 weeks. Stool specimens from enrolled infants and from six term infants without heart disease were analyzed for microbial composition. Plasma cytokines were analyzed weekly in the infants with heart disease.

RESULTS

Healthy control infants had increased total bacteria, total Bacteroidetes and total bifidobacteria compared to the infants with heart disease, but there were no significant differences between the placebo and probiotic groups. Plasma interleukin (IL)10, interferon (IFN)γ and IL1β levels were transiently higher in the probiotic group.

CONCLUSION

Congenital heart disease in infants is associated with dysbiosis. Probiotic B. infantis did not significantly alter the fecal microbiota. Alterations in plasma cytokines were found to be inconsistent.

Necrotising enterocolitis in infants with congenital heart disease: the role of enteral feeds

OBJECTIVE

Necrotising enterocolitis is a rare, though catastrophic complication that may occur in term newborns with congenital heart disease. There is considerable controversy regarding the factors that lead to necrotising enterocolitis in this population. We sought to determine the incidence of necrotising enterocolitis among term and near-term newborns with congenital heart disease, focusing on the relationship of enteral feeding to this complication.

METHODS

In this retrospective study, we identified the incidence of necrotising enterocolitis among 1551 newborns admitted to our cardiac intensive care unit between July 1, 2002 and July 1, 2010. In order to understand the impact of enteral feeding upon the development of necrotising enterocolitis, we undertook a nested 2:1 matched case-control analysis to compare feeding patterns in an age- and lesion-matched control population.

RESULTS

Necrotising enterocolitis developed in 45 term or near-term infants (3%). The majority of these cases, 27 (60%), occurred in the post-operative period after the introduction of enteral feeds. This subgroup was used for matched analysis. There were no differences in enteral feeding patterns among the patients who developed necrotising enterocolitis and their matched controls. The overall mortality rate for patients who developed necrotising enterocolitis was 24.4% (11 out of 45).

CONCLUSIONS

Despite numerous advances in the care of infants with congenital heart disease, necrotising enterocolitis remains a significant source of morbidity and mortality. In these infants, there is no clear relationship between enteral feeding patterns and the development of necrotising enterocolitis in the post-operative period. The benefits of graduated feeding advancements to avoid the development of necrotising enterocolitis remain unproven.

Does milk fortification increase the risk of necrotising enterocolitis in preterm infants with congenital heart disease?

Prematurity and low birth weight adds to the risk of serious congenital heart disease in infants. It may also delay surgical intervention, especially when cardiopulmonary bypass is required, or where an aortopulmonary shunt is necessary to maintain adequate oxygenation. In this setting, neonatologists are faced with the challenge of accelerating the infant's growth to allow for early surgery. We describe the cases of two infants in whom an attempt to fortify the feeds was associated with necrotising enterocolitis, with a lethal outcome in one. The outcome suggests caution in fortifying feeds in premature infants with serious congenital heart disease.

Diastolic flow parameters are not sensitive in predicting necrotizing enterocolitis in patients undergoing hybrid procedure

BACKGROUND

Necrotizing enterocolitis (NEC) is a significant cause of morbidity and mortality in neonates with complex single-ventricle anatomy undergoing stage I palliation. Hybrid approach is another option for initial single-ventricle palliation. The goal of this study was to determine if there were differences in echocardiographic indices between patients undergoing the hybrid procedure who developed NEC vs. those that did not develop NEC.

METHODS

Retrospective chart review was performed on patients who underwent the hybrid procedure. Patients were included if an echocardiogram with adequate Doppler tracings through the patent ductus arteriosus stent was available. Echocardiographic indices measured included antegrade velocity-time integral (VTI), retrograde VTI, effective VTI, VTI regurgitant fraction, VTI retrograde/VTI antegrade ratio, calculated cardiac output, peak antegrade velocity through the ductal stent, retrograde/antegrade time ratio, and percent regurgitant time. Indices were compared in patients who developed NEC (NEC Group) and those who did not develop NEC (No NEC Group). NEC was defined as a Bell Stage ≥2.

RESULTS

Sixty-nine patients met inclusion criteria. Eight of the 69 patients developed NEC. There was no significant difference between the NEC and No NEC Group for antegrade VTI (10.4 ± 3.2 cm vs. 12.7 ± 4.4 cm), retrograde VTI (5.3 ± 1.5 cm vs. 6.1 ± 2.2 cm), effective VTI (5.1 ± 2.9 cm vs. 6.6 ± 3.3 cm), VTI regurgitant fraction (53.6 ± 14.7% vs. 49.7 ± 13.6%), and VTI retrograde/VTI antegrade ratio (0.54 ± 0.15 vs.0.50 ± 0.14). Cardiac output (4.2 ± 1.4 L/min/m(2) vs. 4.8 ± 1.8 L/min/m(2) ) and peak velocity (117.5 ± 28.9 cm/s and 142.4 ± 42.6 cm/s) were also not different between the NEC and No NEC Groups. Furthermore, retrograde/antegrade time ratios (1.6 ± 0.2 vs. 1.7 ± 0.3) and percent retrograde time (60.6 ± 3.0% vs. 62.0 ± 4.0%) were not different between the NEC and No NEC Groups.

CONCLUSION

Echocardiographic indices were not sensitive in determining the development of NEC in patients undergoing the hybrid procedure. Larger studies with more sensitive imaging techniques are required to help risk stratify NEC in this complex patient population.

Enteral feeding in neonates with prostaglandin-dependent congenital cardiac disease: international survey on current trends and variations in practice

BACKGROUND

The benefits of early enteral feeding in neonates are well known and yet the optimal pre-operative nutrition of prostaglandin-dependent infants with congenital cardiac disease remains ill-defined. This survey delineates international nutritional practices and trends with this population.

MATERIALS AND METHODS

Paediatric practitioners responded to an Internet-based survey that explored assessment of feeding practices, criteria for feeding readiness, medication dosing, concurrent feeding with umbilical catheters, and the observed incidence of feeding intolerance. Documented nutritional strategies were not correlated with patient outcomes.

RESULTS

A total of 200 caregivers responded to the survey. Fewer United States caregivers (56%) reported routine pre-operative enteral feeding in prostaglandin-dependent infants when compared with caregivers outside the United States of America (93%). Of those respondents willing to feed, approximately two-thirds did not base their decision on the ductal flow direction. Numerous and heterogeneous parameters were reported to assess feeding readiness. Many caregivers report scepticism with regard to enteral feeding safety in neonates with an umbilical artery catheter, and to a lesser extent in the presence of an umbilical venous catheter. In summary, there is a prevailing lack of consensus regarding pre-operative enteral nutrition to prostaglandin-dependent neonates.

CONCLUSIONS

This survey demonstrates noticeable variations in pre-operative nutritional practices between providers from around the world. Arguments that support or refute this practice have little support in the medical literature. Future studies should aim to demonstrate the safety of such practice and compare the outcomes of prostaglandin-dependent neonates who were pre-operatively enterally fed with those who were not.

Comparison of gastrointestinal morbidity after Norwood and hybrid palliation for complex heart defects

This study aimed to compare the incidence of gastrointestinal complications among infants with single-ventricle heart defects after three first-stage palliation strategies: Norwood-modified Blalock-Taussig shunt (mBTS), Norwood right ventricle-to-pulmonary artery conduit (Sano), and hybrid procedures. A retrospective chart review was performed in a pediatric cardiac intensive care unit at a tertiary care medical center. The subjects were 32 neonates who had undergone single-ventricle palliation including 13 Norwood-mBTS, 11 Sano, and 8 hybrid procedures. The measurements included baseline as well as pre- and postoperative patient characteristics. The primary outcome was postoperative intraabdominal complications, and the secondary outcomes were feeding intolerance and necrotizing enterocolitis (NEC). Intraabdominal complications occurred for 34%, feeding intolerance for 13%, and NEC for 13% of the patients. The hybrid patients had a higher incidence of intraabdominal complications (75%) than the Norwood-mBTS (31%) or Sano (9%) patients (P = 0.01). The relative risk for intraabdominal complications in the hybrid group was 3.6 (95% confidence interval [CI], 1.5-8.7). In the multivariate analysis, the hybrid procedure remained an independent predictor of intraabdominal complications (hazard ratio, 8.4; 95% CI, 2.0-34.5). The hybrid, Norwood-mBTS, and Sano patients did not differ significantly in terms of feeding intolerance (25, 15, and 0%, respectively; P = 0.25) or NEC (25, 8, and 9%; P = 0.46). Gastrointestinal morbidity was common regardless of the palliative approach, although the hybrid patients had the highest incidence of intraabdominal complications. This supports the need for caution in using enteral nutrition with all single-ventricle patients, including the hybrid population. Patients undergoing the hybrid procedure may benefit from implementation of standardized feeding protocols.

Reducing the incidence of necrotizing enterocolitis in neonates with hypoplastic left heart syndrome with the introduction of an enteral feed protocol

OBJECTIVE

Neonates with hypoplastic left heart syndrome are prone to gastrointestinal complications, including necrotizing enterocolitis, during initiation or advancement of enteral feeds. A feeding protocol was developed to standardize practice across a multidisciplinary team. The purpose of this study was to examine the impact of a standardized feeding protocol on the incidence of necrotizing enterocolitis and overall postoperative gastrointestinal morbidity.

DESIGN

Retrospective case-control study.

SETTING

Cardiothoracic intensive care unit of a tertiary care children's hospital.

PATIENTS

Ninety-eight neonates with hypoplastic left heart syndrome admitted to the cardiothoracic intensive care unit after first-stage palliation.

INTERVENTION

A retrospective chart review was performed. Two groups were analyzed: the preprotocol group (n = 52) was examined from January 2000 through December 31, 2001, and the postprotocol group (n = 46) from February 2002 through December 31, 2003.

MEASUREMENTS AND MAIN RESULTS

The incidence of suspected or diagnosed necrotizing enterocolitis as defined by the modified Bell staging criteria was recorded. Data were also collected regarding postoperative day of enteral feed initiation, postoperative day full feeds attained, and postoperative hospital length of stay. Necrotizing enterocolitis was detected in 14 preprotocol (27%) and three postprotocol (6.5%) patients (p < .01). Enteral feeds were initiated later in the postprotocol group (7.5 vs. 5.5 days, p < .001), and number of days to full feeds was also later in the postprotocol group (7 vs. 4 days, p = .02). Hospital length of stay tended to be shorter in the postprotocol group (21.5 vs. 28 days, p = .25).

CONCLUSION

Measures directed at reducing the incidence of necrotizing enterocolitis may reduce morbidity in neonates with hypoplastic left heart syndrome and reduce cost by decreasing hospital length of stay. A standardized feeding protocol instituted to address these problems likely contributed to reducing the incidence of necrotizing enterocolitis in this high-risk population.

Intestinal microbiota and blue baby syndrome: probiotic therapy for term neonates with cyanotic congenital heart disease

Necrotizing enterocolitis (NEC) is the most common intestinal emergency among premature infants. Risk factors in premature infants include immature intestinal immunity and an intestinal microbiota dominated by hospital-acquired bacteria. Some probiotics have been shown to decrease the incidence of NEC in premature infants. Among term infants, NEC is rare. However, among term infants with cyanotic congenital heart disease (CCHD), the incidence of NEC is similar to that of premature infants but with even greater mortality rates. Mechanisms by which NEC occurs in term infants with CCHD are unknown. Of central interest is the potential role of changes in the intestinal microbiota and whether these can be modified with probiotic bacteria; accordingly, we review the literature, propose hypotheses and present the rationale for future studies involving preliminary probiotic clinical trials.

Short- and long-term outcomes of necrotizing enterocolitis in infants with congenital heart disease

OBJECTIVE

Congenital heart disease is a significant risk factor for necrotizing enterocolitis in the term infant. We compared the short- and long-term necrotizing enterocolitis-specific outcomes of infants with congenital heart disease with those of neonates without congenital heart disease.

PATIENTS AND METHODS

A retrospective study of 202 patients with necrotizing enterocolitis treated at our center from May 1999 to August 2007 was conducted. Infants with necrotizing enterocolitis were grouped according to the presence (n = 76) or absence (n = 126) of congenital heart disease. Demographic and necrotizing enterocolitis-specific outcomes were recorded. The groups were compared by nonparametric and chi(2) analyses. Univariate and multivariate odds ratios were determined for each outcome.

RESULTS

The average birth weight and gestational age of the 2 groups were not significantly different. The initial necrotizing enterocolitis severity, as determined by Bell stage, was less for necrotizing enterocolitis subjects with congenital heart disease compared with those without congenital heart disease. When controlling for birth weight and gestational age, the congenital heart disease group had decreased risk of perforation, need for a bowel operation, strictures, need for a stoma, sepsis, and short bowel syndrome compared with the non-congenital heart disease group. Although not statistically significant, subjects with congenital heart disease had a trend toward decreased risk of death from necrotizing enterocolitis, recurrent necrotizing enterocolitis, and need for peritoneal drainage.

CONCLUSIONS

Infants with congenital heart disease and necrotizing enterocolitis have decreased risk of major short- and long-term negative outcomes associated with necrotizing enterocolitis compared with neonates without congenital heart disease. Differences in initial severity, range of age at diagnosis, and prognoses between subjects with necrotizing enterocolitis with and without cardiac disease suggest that necrotizing enterocolitis in the cardiac patient is a distinct disease process and should be labeled cardiogenic necrotizing enterocolitis.

The neonatal intestinal vasculature: contributing factors to necrotizing enterocolitis

Based on the demonstration of coagulation necrosis, it is clear that intestinal ischemia plays a role in the pathogenesis of necrotizing enterocolitis (NEC). Intestinal vascular resistance is determined by a dynamic balance between vasoconstrictive and vasodilatory inputs. In the newborn, this balance heavily favors vasodilation secondary to the copious production of endothelium-derived nitric oxide (NO), a circumstance which serves to ensure adequate blood flow and thus oxygen delivery to the rapidly growing intestine. Endothelial cell injury could shift this balance in favor of endothelin (ET)-1-mediated vasoconstriction, leading to intestinal ischemia and tissue injury. Evidence obtained from animal models and from human tissue collected from infants with NEC implicates NO and ET-1 dysregulation in the pathogenesis of NEC. Strategies focused on maintaining the delicate balance favoring vasodilation in the newborn intestinal circulation may prove to be useful in the prevention and treatment of NEC.

Emerging trends in acquired neonatal intestinal disease: is it time to abandon Bell's criteria?

In the last decade, it has become increasingly clear that necrotizing enterocolitis (NEC) is neither a uniform nor a well-defined disease entity. There are many factors that are forcing this unwelcome realization upon the neonatal and pediatric surgery communities. In the course of this manuscript we will review the history and the physical findings of the disparate etiologies of acquired neonatal intestinal diseases (ANIDs), some which do lead to the common final pathology of NEC and some which do not. New guidelines for distinguishing between ANIDs will also be suggested.

Persistent diastolic flow reversal in abdominal aortic Doppler-flow profiles is associated with an increased risk of necrotizing enterocolitis in term infants with congenital heart disease

OBJECTIVE

Diastolic runoff in the abdominal aorta, with subsequent circulatory mesenteric insufficiency, has been postulated as a cause of necrotizing enterocolitis in term infants with congenital heart disease. With this study we sought to determine whether Doppler-flow characteristics in the abdominal aorta can predict which infants are at specific risk, independent of gestational age and type of congenital heart disease.

PATIENTS AND METHODS

We conducted a case-control study of term infants with congenital heart disease and proven necrotizing enterocolitis (n = 18) compared with gestational age-matched and diagnosis-matched control subjects (n = 20). Abdominal aortic Doppler velocities, time intervals, and reversals were analyzed. Groups were compared, and independent risk factors for necrotizing enterocolitis were determined.

RESULTS

The groups were similar with regard to weight, pulse pressure, use of prostaglandins or inotropes, presence of a patent ductus arteriosus, and systolic function. However, 47% of the case subjects with necrotizing enterocolitis had persistent retrograde diastolic flow in the abdominal aorta compared with 15% of the control subjects. When adjusting for multiple risk factors, persistent diastolic flow reversal remained the only factor significantly associated with necrotizing enterocolitis.

CONCLUSION

Persistent diastolic flow reversal in the abdominal aortic Doppler profile is associated with an increased risk of necrotizing enterocolitis in term infants with congenital heart disease irrespective of gestational age or anatomic type of congenital heart disease.

The epidemiology and pathogenesis of necrotizing enterocolitis

Necrotizing enterocolitis (NEC), a syndrome characterized by crepitant necrosis of the bowel, has emerged as the most common neonatal gastrointestinal emergency in many countries of the world. In the United States, NEC strikes 1 to 8% of patients admitted to neonatal intensive care units, almost all of whom are premature infants. The incidence is low in certain countries wity a low premature birth rate, e.g., Japan. Two theories of pathogenesis are: the Santulli theory, which implicates three factors: ischaemia, bacteria and substrate; and the Lawrence theory, which stresses the injurious role of bacterial toxins on the immature gut of the preterm infant. Clinical and experimental evidence support each of the theories, but neither theory can explain certain clinical phenomena, particularly the resistance to NEC manifested by more than 90% of preterm infants, who never develop the syndrome. A unifying hypothesis of pathogenesis and a mathematical model of NEC are outlined. Because clustering of cases may occur, the design of clinical trials of preventive measures for NEC must include simultaneous control infants.

Mesenteric blood flow velocities in the newborn with single-ventricle physiology: modified Blalock-Taussig shunt versus right ventricle-pulmonary artery conduit

BACKGROUND

Neonates with ductal-dependent single-ventricle congenital heart disease palliated with a modified Blalock-Taussig shunt (mBTS) commonly have retrograde diastolic flow in the aorta, which may place them at increased risk of mesenteric ischemia. Recently, palliation with a right ventricle-to-pulmonary artery conduit, known as the Sano procedure, has been shown to eliminate retrograde diastolic flow, theoretically leading to better systemic perfusion.

OBJECTIVE

To compare the changes in superior mesenteric artery (SMA) and celiac artery velocities and flow after a bolus enteral feed in patients with single-ventricle congenital heart disease palliated with an mBTS vs. those palliated with the right ventricle-to-pulmonary artery conduit.

DESIGN

Prospective clinical study.

SETTING

Cardiothoracic intensive care unit and pediatric ward of a tertiary care children's hospital.

PATIENTS

A total of 27 patients with single-ventricle congenital heart disease (15 with mBTS, 12 with Sano) after stage-1 palliation.

INTERVENTION

Doppler ultrasound of the SMA and celiac artery was performed 30 mins before and after a bolus enteral feed.

MEASUREMENTS AND MAIN RESULTS

SMA and celiac artery peak systolic flow velocity, mean flow velocity, and time-velocity integral were measured. After a bolus enteral feed, 8 of 15 infants palliated with an mBTS had retrograde diastolic flow through the SMA yet demonstrated significant increases in all variables of both the SMA and celiac artery flow velocities (SMA peak systolic flow velocity: 0.96 +/- 0.33 vs. 1.2 +/- 0.4 m/sec, p = .01). Those palliated with the Sano procedure did not demonstrate SMA retrograde diastolic flow but also did not have any significant changes in their mesenteric flow variables (SMA peak systolic flow velocity: 0.79 +/- 0.16 vs. 0.89 +/- 0.26 m/sec, p = .2).

CONCLUSION

Postprandial retrograde diastolic flow was observed in the majority of patients palliated with an mBTS vs. none of the patients in the Sano group. However, contrary to expectations, postprandial mesenteric blood flow velocities in those palliated with an mBTS are significantly higher than in Sano patients, although the increase is not as high as that historically seen in normal neonates. This may place this population at risk for mesenteric ischemia and feeding intolerance in the postoperative period, and the risk may be even greater for those neonates palliated with a right ventricle-to-pulmonary artery conduit.

Mesenteric blood flow response to feeding after systemic-to-pulmonary arterial shunt palliation

BACKGROUND

We hypothesized that the splanchnic circulation protects against diastolic steal through a systemic-to-pulmonary arterial shunt by reducing its resistance. To test the hypothesis we compared the basal and postprandial mesenteric blood flow velocities and vascular resistance in infants after shunt palliation for their underlying cyanotic heart disease with those in nonshunted infants.

METHODS

The basal and postprandial superior mesenteric arterial (SMA) time-average flow velocity (TAMV), end-diastolic flow velocity (EDFV), and relative resistance were assessed in 23 infants with congenital heart disease. The findings in the 9 shunted infants (group I) were compared with those in 14 nonshunted ones (group II).

RESULTS

In group II, TAMV (0.25 +/- 0.07 versus 0.33 +/- 0.09 m/s, p < 0.001) and EDFV (0.08 +/- 0.04 versus 0.11 +/- 0.04 m/s, p = 0.003) increased, while SMA relative resistance decreased (297 +/- 121 versus 198 +/- 73 mm Hg/ms(-1), p < 0.001) postprandially. Similarly, in group I, TAMV (0.35 +/- 0.13 versus 0.48 +/- 0.19 m/s, p = 0.008) increased, while SMA relative resistance decreased (182 +/- 61 versus 116 +/- 38 mm Hg/ms(-1), p = 0.005) after feeding. However, whereas basal and postprandial diastolic flow was antegrade in group II, absent or retrograde diastolic flow was characteristic of group I (preprandial, -0.10 +/- 0.07 m/s; postprandial, -0.13 +/- 0.06 m/s). Furthermore, group I had significantly lower SMA relative resistance both before (p = 0.02) and after (p = 0.006) feeding.

CONCLUSIONS

Profound disturbance of splanchnic perfusion occurs in infants palliated with a systemic-to-pulmonary arterial shunt. Their basal and postprandial SMA diastolic blood flow is either absent or reversed. The lowering of basal and postprandial resistance of the splanchnic circulation probably represents an adaptive mechanism to counteract such diastolic steal.

Neonatal necrotizing enterocolitis: clinical considerations and pathogenetic concepts

Necrotizing enterocolitis (NEC), a disease affecting predominantly premature infants, is a leading cause of morbidity and mortality in neonatal intensive care units. Although several predisposing factors have been identified, such as prematurity, enteral feeding, and infection, its pathogenesis remains elusive. In the past 20 years, we have established several animal models of NEC in rats and found several endogenous mediators, especially platelet-activating factor (PAF), which may play a pivotal role in NEC. Injection of PAF induces intestinal necrosis, and PAF antagonists prevent the bowel injury induced by bacterial endotoxin, hypoxia, or challenge with tumor necrosis factor-a (TNF) plus endotoxin in adult rats. The same is true for lesions induced by hypoxia and enteral feeding in neonatal animals. Human patients with NEC show high levels of PAF and decreased plasma PAF-acetylhydrolase, the enzyme degrading PAF. The initial event in our experimental models of NEC is probably polymorphonuclear leukocyte (PMN) activation and adhesion to venules in the intestine, which initiates a local inflammatory reaction involving proinflammatory mediators including TNF, complement, prostaglandins, and leukotriene C4. Subsequent norepinephrine release and mesenteric vasoconstriction result in splanchnic ischemia and reperfusion. Bacterial products (e.g., endotoxin) enter the intestinal tissue during local mucosal barrier breakdown, and endotoxin synergizes with PAF to amplify the inflammation. Reactive oxygen species produced by the activated leukocytes and by intestinal epithelial xanthine oxidase may be the final pathway for tissue injury. Protective mechanisms include nitric oxide produced by the constitutive (mainly neuronal) nitric oxide synthase, and indigenous probiotics such as Bifidobacteria infantis. The former maintains intestinal perfusion and the integrity of the mucosal barrier, and the latter keep virulent bacteria in check. The development of tissue injury depends on the balance between injurious and protective mechanisms.

Necrotizing enterocolitis in neonates with congenital heart disease: risk factors and outcomes

OBJECTIVE

Necrotizing enterocolitis (NEC) is primarily a disease of the premature infant. Among children born at term, however, congenital heart disease may be an important predisposing factor for this condition. To determine risk factors for NEC in patients with congenital heart disease, we conducted a case-control study of neonates with cardiac disease admitted to the cardiac intensive care unit at our center during the 4-year period from January 1995 to December 1998.

METHODS

Cardiac diagnosis and age at admission were analyzed for association with NEC among the 643-patient inception cohort. Demographic, preoperative, and operative variables were recorded retrospectively in 21 neonates with congenital heart disease who developed NEC and 70 control neonates matched by diagnosis and age at admission. Using parametric and nonparametric analysis, cases and controls were compared with respect to previously identified risk factors for NEC.

RESULTS

Among the entire cohort of 643 neonates with heart disease admitted to the cardiac intensive care unit, diagnoses of hypoplastic left heart syndrome (odds ratio [OR] = 3.8 [1.6-9.1]) and truncus arteriosus or aortopulmonary window (OR = 6.3 [1.7-23.6]) were independently associated with development of NEC by multivariable analysis. In the case-control analysis, earlier gestational age at birth (36.7 +/- 2. 7 weeks vs 38.1 +/- 2.3 weeks), prematurity (OR = 3.9 [1.2-12.5]), highest dose of prostaglandin >0.05 microg/kg/minute (OR = 3.9 [1. 2-12.5]), and episodes of low cardiac output (meeting specific laboratory criteria) or clinical shock (OR = 6.5 [1.8-23.5]) correlated with the development of NEC. Earlier gestational age and episodes of low output were the only factors that remained significantly associated with NEC by multivariable analysis. Although there was no difference in hospital mortality between patients with and without NEC, mean hospital stay was significantly longer in those who developed NEC (36 +/- 22 days vs 19 +/- 14 days).

CONCLUSIONS

The risk of NEC in neonates with congenital heart disease is substantial. Factors associated with an elevated risk of NEC in infants with heart disease include premature birth, hypoplastic left heart syndrome, truncus arteriosus, and episodes of poor systemic perfusion or shock. Heightened suspicion is warranted in newborns with these risk factors.

Outcome of preterm infants with congenital heart disease

OBJECTIVES AND STUDY DESIGN

To evaluate the morbidity and mortality of preterm infants with congenital heart disease (CHD), a chart review was performed for infants with CHD, excluding isolated patent ductus arteriosus, who were <37 weeks' gestation, weighed <2500 g, and were admitted to our neonatal intensive care unit from 1976 to 1999 (N = 201).

RESULTS

Patients in the study represented 1.9% of the total neonatal intensive care unit population <37 weeks' gestation and <2500 g. The median gestational age was 33 weeks, and the mean birth weight was 1852 g. CHD diagnosis frequencies were similar to those reported in other large incidence studies, except for a higher percentage of conotruncal defects. The risk of necrotizing enterocolitis was 1.7 times higher and the overall mortality twice as high in our patients compared with patients in the neonatal intensive care unit who did not have CHD. Cardiac surgery (n = 133) was performed on 108 patients. During the recent period of 1985 to 1999, compared with our institution's overall results for CHD surgery, the operative mortality rate was 10.4% versus 5.4% for closed procedures and 25.4% versus 10.5% for open procedures. The actuarial survival rate is 51% at 10 years; survival improved as the study period progressed.

CONCLUSIONS

Infants with both CHD and prematurity did significantly worse than either group alone. Such outcome data are required for proper allocation of resources to care for this high-risk pediatric population.

Successful arterial switch operation in a low-birth-weight neonate who had transposition of the great arteries and advanced necrotizing enterocolitis

A low-birth-weight (LBW; 1,940 g) girl was born at the gestational age of 36 weeks without any perinatal insult. Transposition of the great arteries (TGA) with a large patent ductus arteriosus (PDA) and interatrial shunt was detected. Stage IIIB necrotizing enterocolitis (NEC) developed 46 hours after birth. She received ileostomy and drainage. Arterial switch operation was successfully performed at 23 days of age when her weight was 1,900 g. The enterostomy was successfully repaired at 104 days of age.

Necrotizing enterocolitis in a term infant with coarctation of the aorta complex

Necrotizing enterocolitis (NEC) sometimes occurs in term infants with congenital heart disease. This article reports a rare case of a term infant with coarctation of the aorta complex who developed NEC on the 8th day after birth. Spontaneous closure of the ductus arteriosus in the 1st week of life may cause intestinal ischemia and hypoxia with resultant NEC.

Evaluation of low dose prostaglandin E1 treatment for ductus dependent congenital heart disease

This study reports our experience with low-dose prostaglandin E1 (PGE1) treatment of 91 newborns with ductus dependent congenital heart disease (CHD). PGE1 efficacy, side-effects as well as the cardiovascular and respiratory profile of the patients were analysed. PGE1 doses > 0.02 microgram/kg per minute were used for only 5.3% of the total 23,656 h of treatment. The mean systolic blood pressures did not differ from the normal mean for patients with cyanotic CHD, while the diastolic values were lowered. Respiratory support was required only during 13.7% of the total treatment time. Apnoeas occurred in 21 (38%) of the 55 spontaneously breathing infants, who all had a cyanotic CHD. The incidence of apnoeas was lower during treatment with doses < 0.01 microgram/kg per minute.

CONCLUSION

PGE1 can be successfully administered in lower doses than previously recommended. Especially high initial doses can be avoided and low maintenance doses allow long-term treatment without serious complications.

Epidemiology of necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a worldwide problem that has emerged in the past 25 years as the most common gastrointestinal emergency in neonatal intensive care units (NICU). In the United States the incidence ranges from 1 to 7.7% of NICU admissions. Ninety percent of the patients are premature infants. Mucosal injury, bacterial colonization and formula feeding are the three major pathogenetic factors that have been documented in most infants who have developed NEC. However, NEC may develop only if a threshold of injury, imposed by the coincidence of at least two of three events (intestinal ischemia, pathogenic bacteria, and excess of protein substrate) is exceeded. Immunological immaturity of the gut in premature babies may represent the crucial risk factor.

Necrotizing enterocolitis. New thoughts about pathogenesis and potential treatments

Necrotizing enterocolitis (NEC) remains a major cause of morbidity and mortality in premature infants. An incomplete understanding of its pathogenesis has hampered efforts to devise an effective preventative strategy. New insights into the pathogenesis of NEC, particularly at the cellular and biochemical level, however, offer a rational basis for the development of new approaches to this disease.

Necrotizing enterocolitis: a review of pathogenetic mechanisms and implications for prevention

Necrotizing enterocolitis (NEC) is a devastating gastrointestinal disease of premature neonates that accounts for 3000 to 4000 deaths each year in the United States. The pathogenesis is not well understood, however theories suggest that prematurity, enteral feeding, bacterial colonization, and intestinal ischemia contribute to the intestinal injury. Furthermore, recent studies have shown that platelet activating factor and perhaps other inflammatory mediators mediate bowel necrosis in animals and possibly in humans. Although no specific intervention for NEC treatment exists, preventive therapy using either enteral IgA supplementation, breast milk feeding, antibiotic prophylaxis, or exogenous steroid administration have reduced the incidence of this overwhelming disease in small randomized trials. These modalities and perhaps PAF antagonists or other inflammatory mediator inhibitors may reduce the incidence or severity of NEC in the next several years.

Mesenteric ischemia in hypoplastic left heart syndrome

Hypoplastic left heart syndrome (HLHS) has been widely viewed as a uniformly fatal form of congenital heart disease. Between January 1984 and December 1990, 387 patients with the diagnosis of HLHS were treated at this institution. Mesenteric ischemia was clinically diagnosed in 31 patients (8% incidence) and confirmed by pathology or surgery in 25 of those patients. The mean age at the time of onset was 17.5 +/- 5.4 weeks and only 13% were premature newborns. In 80% of the patients a low perfusion state and significant hypotension were documented within 48 hours prior to the diagnosis of bowel ischemia. Nine patients (29%) required operative intervention (bowel resection 4, diffuse ischemia 3, and simple drainage 2). Overall, at operation or at autopsy, nine patients (29%) had diffuse gastrointestinal ischemia. Of 31 patients with mesenteric ischemia, 26 children (84%) died shortly after onset of the gastrointestinal symptoms regardless of means of management. Five patients (10%) initially improved with aggressive medical and/or surgical management; however, 4 subsequently died secondary to complications of their primary cardiac disease. Therefore, the overall mortality of patients with mesenteric ischemia was 97%. Previous reports have estimated that up to 7% of full-term newborns with symptomatic congenital heart disease may develop necrotizing enterocolitis (NEC). Our unique group of patients with HLHS is comprised mostly of full-term infants who developed onset of mesenteric ischemia at a mean age of 4 months associated with an underlying low perfusion state. This mesenteric ischemia has been erroneously identified as NEC.(ABSTRACT TRUNCATED AT 250 WORDS)

Gastric-outlet obstruction induced by prostaglandin therapy in neonates

BACKGROUND

An infusion of prostaglandin E1 is widely used to maintain patency of the ductus arteriosus in neonates with congenital heart disease. After gastric-outlet obstruction was recognized in several infants who received prostaglandin E1, we studied the association between the drug and this complication.

METHODS

We evaluated all neonates who received prostaglandin E1 in our hospital between October 1, 1989, and September 30, 1991, for clinical, radiologic, or pathological evidence of acute gastric-outlet obstruction.

RESULTS

Of the 74 neonates evaluated, 65 had no signs of gastric obstruction and were considered normal; 5 had clinical and radiologic or pathological evidence of gastric obstruction consistent with the presence of antral mucosal hyperplasia. The remaining four neonates had clinical signs of gastric obstruction, but no radiologic or pathological examinations were performed. The 5 neonates with antral hyperplasia had received prostaglandin E1 for longer periods (mean [+/- SD] duration, 569 +/- 341 hours) than the 65 normal neonates (54 +/- 58 hours, P less than 0.001) or the 4 neonates with clinical signs of gastric obstruction (119 +/- 60 hours, P less than 0.05). The cumulative dose of prostaglandin E1 was higher in the neonates with antral hyperplasia (2982 +/- 1392 micrograms per kilogram of body weight) than in the normal neonates (279 +/- 270 micrograms per kilogram, P less than 0.001) or the neonates with signs of gastric obstruction (528 +/- 306 micrograms per kilogram, P less than 0.01). In two neonates with antral hyperplasia, the cessation of therapy lessened the gastric-outlet obstruction.

CONCLUSIONS

The administration of prostaglandin E1 to neonates can cause gastric-outlet obstruction due to antral hyperplasia. Neonates who receive prostaglandin E1 at recommended doses for more than 120 hours should be closely monitored for evidence of antral hyperplasia.

Hemodynamic and permeability characteristics of acute experimental necrotizing enterocolitis

We examined the local hemodynamic response of intestinal loops during acute necrotizing enterocolitis (NEC) in anesthetized rabbits. NEC was induced in ileal loops by transmural injection of a solution containing casein (10 mg/ml) and calcium gluconate (50 mg/ml) acidified to pH 4.0 with propionic or acetic acid. Control loops received casein only (pH 5.0). Mucosal damage was quantified by the blood-to-lumen movement of [51Cr]EDTA, fluid shifts into the lumen, and histology. Mean arterial pressure and loop blood flow were steady over the 3-hr period, loop fluid volume decreased, and there was no evidence of necrosis or epithelial damage. In loops receiving acidified casein and calcium gluconate, there was an immediate dramatic increase in loop blood flow that returned to baseline by 50 min. In addition, loop fluid volume was dramatically increased, necrosis was noted in the form of blunting and loss of villi, and sevenfold increase in [51Cr]EDTA permeability was evident. Administration of CV 1808 (30 mg/kg/hr), a selective adenosine2 agonist, which maintained and elevated loop blood flow throughout the 3 hr protocol, failed to alter the changes in loop fluid volume or prevent necrosis. Histamine levels in loop fluid levels were significantly elevated 20-30 min after NEC induction when compared to saline controls, indicating an early activation of mucosal defenses with this luminal insult. Thus, this model of NEC is characterized by a transient, acute hyperemia, increased intestinal permeability, and histamine release. As mucosal damage was independent of ischemia and could not be prevented by vasodilatory therapy, this model supports the clinical findings that NEC is correlated with luminal factors related to feeding and independent of cardiovascular stress.

Effect of indomethacin on superior mesenteric artery blood flow velocity in preterm infants

In 15 preterm infants with symptomatic patent ductus arteriosus, blood flow velocity changes in the superior mesenteric artery were investigated with Doppler ultrasound just before and during the first 12 hours after a single dose of indomethacin. Indomethacin administration led to an instantaneous decrease in all infants of temporal mean flow velocity in the superior mesenteric artery, which was maximal 10 minutes after administration of indomethacin, followed by a more sustained recovery, slightly greater than baseline values, 12 hours after indomethacin treatment. Simultaneously determined temporal mean flow velocity of the anterior cerebral artery, used as an indicator of changes in cerebral blood flow, had a similar pattern as in the mean flow velocity in the superior mesenteric artery (r = 0.49; p less than 0.001). Our data suggest that indomethacin lowered blood supply to the bowel, similar to its action on cerebral blood flow.

Necrotizing enterocolitis: an overlooked life-threatening complication of acute diarrhoeal illness in infants and children

A 7-month-old girl developed necrotizing enterocolitis with extensive pneumatosis intestinalis following an acute diarrhoeal illness. This was preceded by the use of an anti-motility drug and repeated attacks of paralytic ileus. It is noteworthy that all the published cases of necrotizing enterocolitis following acute diarrhoeal illness in infants and children are from tropical countries. This might be related to the use of anti-diarrhoeal drugs and associated malnutrition resulting in hypokalaemia and hypoalbuminaemia.