Concurrent use of indomethacin and dexamethasone increases the risk of spontaneous intestinal perforation in very low birth weight neonates

Mortality and neurodevelopmental outcomes at 2 years' corrected age of very preterm infants with necrotising enterocolitis or spontaneous intestinal perforation: The EPIPAGE-2 cohort study

PURPOSE

The primary objective was to evaluate the impact of necrotising enterocolitis (NEC) and spontaneous intestinal perforation (SIP) on mortality and neurodevelopmental outcomes at 2 years' corrected age (CA) in infants born before 32 weeks' gestation (WG).

METHODS

We studied neurodevelopment at 2 years' CA of infants with NEC or SIP who were born before 32 WG from the EPIPAGE-2 cohort study. The primary outcome was death or the presence of moderate-to-severe motor or sensory disability defined by moderate-to-severe cerebral palsy or hearing or visual disability. The secondary outcome was developmental delay defined by a score < 2 SDs below the mean for any of the five domains of the Ages and Stages Questionnaire.

RESULTS

At 2 years' CA, 46% of infants with SIP, 34% of infants with NEC, and 14% of control infants died or had a moderate-to-severe sensorimotor disability (p < 0.01). This difference was mainly due to an increase in in-hospital mortality in the infants with SIP or NEC. Developmental delay at 2 years' CA was more frequent for infants with SIP than controls (70.8% vs 44.0%, p = 0.02) but was similar for infants with NEC and controls (49.3% vs 44.0%, p = 0.5). On multivariate analysis, the likelihood of developmental delay was associated with SIP (adjusted odds ratio = 3.0, 95% CI 1.0-9.1) but not NEC as compared with controls.

CONCLUSION

NEC and SIP significantly increased the risk of death or sensorimotor disability at 2 years' CA. SIP was also associated with risk of developmental delay at 2 years' CA.

Association of Intrapartum Drugs with Spontaneous Intestinal Perforation: A Single-Center Retrospective Review

OBJECTIVE

Spontaneous intestinal perforation (SIP) occurs commonly in extremely low gestational age newborns (ELGANs; <30 weeks' GA). Early, concurrent neonatal use of indomethacin (Neo_IN) and hydrocortisone (Neo_HC) is a known risk for SIP. Mothers in premature labor often receive indomethacin (Mat_IN) for tocolysis and steroids (Mat_S) for fetal maturation. Coincidentally, ELGANs may receive Neo_IN or Neo_HC within the first week of life. There are limited data on the effect of combined exposures to maternal and neonatal medications. We hypothesized that proximity exposure to these medications may increase the risk of SIP.

STUDY DESIGN

We reviewed the medical records of ELGANs from June 2014 to December 2019 at a single level III neonatal intensive care unit. We compared antenatal and postnatal indomethacin and steroid use between neonates with and without SIP. For analysis, chi-square, Student's t-test, Fisher's exact test, and Mann-Whitney U tests were used.

RESULTS

Among 417 ELGANs, SIP was diagnosed in 23, predominantly in neonates < 26 weeks' GA (n = 21/126, 16.7%). Risk factors analysis focused on this GA cohort in which SIP was most prevalent. Mat_IN administration within 2 days of delivery increased SIP risk (odds ratio: 3; 95% confidence interval: 1.25-7.94; p = 0.036). Neo_HC was not independently associated with SIP (p = 0.38). A higher proportion of SIP group had close temporal exposure of Mat_IN and Neo_HC compared with the non-SIP group, though not statistically significant (14 vs. 7%, p = 0.24).

CONCLUSION

Peripartum Mat_IN was associated with increased risk for SIP in this small study sample. Larger studies are needed to further delineate SIP risk from the interaction of peripartum maternal medication with early postnatal therapies and disease pathophysiology.

KEY POINTS

· Perinatal indomethacin is associated with SIP in preterm infants born at less than 26 weeks.. · Temporal proximity of prenatal/postnatal medication exposure matters.. · Indomethacin and Hydrocortisone the risks, benefits, and timing related to SIP..

Clinical Dilemma Involving Treatments for Very Low-Birth-Weight Infants and the Potential Risk of Necrotizing Enterocolitis: A Narrative Literature Review

Necrotizing enterocolitis (NEC) is a critical gastrointestinal emergency with substantial morbidity and mortality risks, especially for very low-birth-weight (VLBW) infants, and unclear multifactorial pathophysiology. Whether common treatments for VLBW infants increase the NEC risk remains controversial. Indomethacin (utilized for patent ductus arteriosus) offers benefits but is concerning because of its vasoconstrictive impact on NEC susceptibility. Similarly, corticosteroids used to treat bronchopulmonary dysplasia may increase vulnerability to NEC by compromising immunity and altering the mesenteric blood flow. Histamine-2 receptor blockers (used to treat gastric bleeding) may inadvertently promote NEC by affecting bacterial colonization and translocation. Doxapram (used to treat apnea) poses a risk of gastrointestinal disturbance via gastric acid hypersecretion and circulatory changes. Glycerin enemas aid meconium evacuation but disrupt microbial equilibrium and trigger stress-related effects associated with the NEC risk. Prolonged antibiotic use may unintentionally increase the NEC risk. Blood transfusions for anemia can promote NEC via interactions between the immune response and ischemia-reperfusion injury. Probiotics for NEC prevention are associated with concerns regarding sepsis and bacteremia. Amid conflicting evidence, this review unveils NEC risk factors related to treatments for VLBW infants, offers a comprehensive overview of the current research, and guides personalized management strategies, thereby elucidating this clinical dilemma.

Prophylactic indomethacin, antenatal betamethasone, and the risk of intestinal perforation in infants <28 weeks' gestation

OBJECTIVE

To determine if intestinal perforations before 14 days (either spontaneous (SIP) or necrotizing enterocolitis-induced) are increased when infants who received antenatal betamethasone shortly before birth are treated with prophylactic indomethacin (PINDO).

STUDY DESIGN

Observational study of 475 infants <28 week's gestation assigned to either a PINDO-protocol (n = 231) or expectant management protocol (n = 244) during consecutive protocol epochs.

RESULTS

Intestinal perforations before 14 days occurred in 33/475 (7%). In unadjusted and adjusted models, we found no associations between PINDO-protocol and intestinal perforations. PINDO-protocol did not increase intestinal perforations or SIP-alone even when given to infants who received betamethasone <7 or <2 days before delivery. 213/231 (92%) PINDO-protocol infants actually received indomethacin. The results were unchanged when examined just in those who received indomethacin.

CONCLUSION

In our study, early intestinal perforations and SIP-alone were not increased when PINDO was used by protocol in infants who received antenatal betamethasone shortly before birth.

Spontaneous intestinal perforation (SIP) will soon become the most common form of surgical bowel disease in the extremely low birth weight (ELBW) infant

Recent data have revealed declines in the prevalence rates of NEC over the last decade in premature infants. In contrast, SIP has either remained steady or risen during the same epoch. These trends are consistent with our knowledge of the clinical arena. The ability to discern SIP contamination within NEC datasets has slowly improved. Additionally, quality improvement efforts are being utilized to reduce NEC through stewardship of antibiotics, acid inhibitors, central lines and blood products, as well as optimization of human milk diets. These forces are moving us to a new era, where NEC will no longer be the dominant surgical intestinal disease of the extremely preterm neonate. Indeed, in the extremely low birth weight (ELBW) population, SIP may already be the most prevalent reason for abdominal surgery. In this perspective, the reader will find supporting data and references for these assertions as well as predictions for the future.

Pharmacotherapy in Bronchopulmonary Dysplasia: What Is the Evidence?

Bronchopulmonary Dysplasia (BPD) is a multifactorial disease affecting over 35% of extremely preterm infants born each year. Despite the advances made in understanding the pathogenesis of this disease over the last five decades, BPD remains one of the major causes of morbidity and mortality in this population, and the incidence of the disease increases with decreasing gestational age. As inflammation is one of the key drivers in the pathogenesis, it has been targeted by majority of pharmacological and non-pharmacological methods to prevent BPD. Most extremely premature infants receive a myriad of medications during their stay in the neonatal intensive care unit in an effort to prevent or manage BPD, with corticosteroids, caffeine, and diuretics being the most commonly used medications. However, there is no consensus regarding their use and benefits in this population. This review summarizes the available literature regarding these medications and aims to provide neonatologists and neonatal providers with evidence-based recommendations.

Using machine learning analysis to assist in differentiating between necrotizing enterocolitis and spontaneous intestinal perforation: A novel predictive analytic tool

PURPOSE

Necrotizing enterocolitis (NEC) and spontaneous intestinal perforation (SIP) are devastating diseases in preterm neonates, often requiring surgical treatment. Previous studies evaluated outcomes in peritoneal drain placement versus laparotomy, but the accuracy of the presumptive diagnosis remains unknown without bowel visualization. Predictive analytics provide the opportunity to determine the etiology of perforation and guide surgical decision making. The purpose of this investigation was to build and evaluate machine learning models to differentiate NEC and SIP.

METHODS

Neonates who underwent drain placement or laparotomy NEC or SIP were identified and grouped definitively via bowel visualization. Patient characteristics were analyzed using machine learning methodologies, which were optimized through areas under the receiver operating characteristic curve (AUROC). The model was further evaluated using a validation cohort.

RESULTS

40 patients were identified. A random forest model achieved 98% AUROC while a ridge logistic regression model reached 92% AUROC in differentiating diseases. When applying the trained random forest model to the validation cohort, outcomes were correctly predicted.

CONCLUSIONS

This study supports the feasibility of using a novel machine learning model to differentiate between NEC and SIP prior to any intended surgical interventions.

LEVEL OF EVIDENCE

level II TYPE OF STUDY: Clinical Research Paper.

Antenatal Risk Factors Associated with Spontaneous Intestinal Perforation in Preterm Infants Receiving Postnatal Indomethacin

OBJECTIVE

To determine if antenatal variables affect the risk of spontaneous intestinal perforation (SIP) among preterm infants when prophylactic indomethacin is used.

STUDY DESIGN

Retrospective case-control study of infants <29 weeks of gestational age between January 2010 and June 2018 at one hospital. SIP was defined as acute abdominal distension and pneumoperitoneum without signs of necrotizing enterocolitis at <14 days of life. Each case (n = 57) was matched with 2 controls (n = 114) for gestational age and birth year. Maternal and infant data were abstracted until the SIP or equivalent day for controls. Univariate analyses were followed by adjusted conditional logistic regressions and reported as OR and 95% CI.

RESULTS

Mothers of cases were younger, more often delivering multiples (31% vs 14%, P = .007), and less abruptions (15% vs 29%, P = .045) but did not differ in intra-partum betamethasone, magnesium, or indomethacin use. Prophylactic indomethacin was given on day 1 to 99% of infants. SIP was associated with a shorter interval from last betamethasone dose to delivery (46 hours vs 96 hours, P = .01). Dopamine use (14% vs 4%, P = .02), volume expansion (23% vs 8%, P = .003), and high grade intraventricular hemorrhage (28% vs 8%, P = .0008) were related postnatal factors. The adjusted odds of SIP increased by 1% for each hour decrease between the last dose of betamethasone and delivery (OR 1.01, 95% CI 1.002-1.019) and with multiple births (OR 2.66, 95% CI 1.05-6.77).

CONCLUSIONS

Antenatal betamethasone given shortly before delivery is associated with an increased risk of SIP. Potential interaction with medications such as postnatal indomethacin needs study.

Spontaneous intestinal perforation associated with premature twin infants

OBJECTIVE

Identify perinatal risk factors associated with SIPSTUDY DESIGN:This was a retrospective case-control study of SIP in infants born at ≤28 weeks of gestation and admitted between 1995 and 2016 at a tertiary care NICU. Infants with NEC or other GI abnormalities were excluded. Cases of SIP were matched with gestational age-matched controls with the closest birth date. Maternal, infant and birth related factors were evaluated using univariate analyses and significant factors were evaluated using multiple logistic regression.

RESULT

25 cases of SIP were matched with 25 controls. No maternal factors reached statistical significance. Being one of twins increased the odds of SIP 29-fold. Birth-order or weight-discrepancy in twin had no association of SIP within twin pairs.

CONCLUSION

Twins are at significantly higher risk for SIP. The association of SIP and twin gestation was independent of previously reported risk factors of perinatal indomethacin or magnesium sulfate and merits further study.

Gut Injury and the Microbiome in Neonates

The causes of neonatal gut injury are multifactorial and include ischemia, tissue hypoxia due to anemia, excessive inflammation, deficiency of growth factors, and food protein sensitivity. The developing intestinal microbiome plays a role in some of these forms of intestinal injury but knowledge of its relative role in each remains poorly understood. Commensal bacteria are required for normal immune development and immune tolerance. Dysbiosis in the neonatal gut that alters the patterns of commensal and pathogenic bacteria may accentuate gut injury.

Necrotizing Enterocolitis: The Future

Progress in our understanding of the pathophysiology, prevention and treatment of necrotizing enterocolitis (NEC) has been hampered for many reasons. Included among these is the fact that what we are calling "NEC" is likely to represent different disease processes, which need to be delineated before evaluating individual pathogenic mechanisms and attempting to develop predictive and diagnostic biomarkers. Treatment is also likely to be hampered because not all of the different entities called "NEC" will respond to the same regimen. In this review, some of these entities will be discussed in more detail, with suggestions for refining our approach toward improving methods for their diagnosis, prevention and treatment.

Refractory Ileal Perforations in a Cytomegalovirus-Infected Premature Neonate Resolved After Ganciclovir Therapy

Severe neonatal gastrointestinal diseases such as necrotizing enterocolitis or spontaneous intestinal perforation are potentially lethal conditions which predominantly occur in preterm infants. Cytomegalovirus (CMV), which is known to cause congenital and acquired infections in the newborns, has also been implicated in such severe gastrointestinal diseases in premature infants. However, the pathogenic role of CMV and effect of antiviral therapy in severe gastrointestinal disease in premature neonates is currently unclear. We present an infant, born at 26-weeks' gestation, presented with progressive dyspepsia and abdominal distention after the closure of the symptomatic patent ductus arteriosus at the day of life (DOL) 4, requiring the emergent surgery for ileal perforation at the DOL8. After the surgery, abdominal symptoms persisted and the second emergent surgery was performed for the recurrent ileal perforation at DOL17. Even then the abdominal symptoms prolonged and pathological examination in the affected intestine at the second surgery showed CMV inclusion body. Immunoreactivity for CMV antigen was detected in the specimen at the first surgery on DOL8. Blood and urinary CMV-DNA were detected at DOL28. CMV-DNA was also detected in the dried umbilical cord which was obtained within a week from birth. A 6-week course of intravenous ganciclovir (12 mg/kg/day) was started at DOL34 and then symptoms resolved along with decreasing blood CMV-DNA. Pathological findings characteristic of CMV were not detected in the resection specimen at the ileostomy closure at DOL94. These observations indicate that anti-CMV therapy may be beneficial for some premature infants with severe CMV-associated gastrointestinal diseases and warrants further studies focusing on pathogenic role, diagnosis, treatment and prevention of this underrecognized etiology of severe gastrointestinal diseases particularly in premature neonates.

To Feed or Not to Feed: A Critical Overview of Enteral Feeding Management and Gastrointestinal Complications in Preterm Neonates with a Patent Ductus Arteriosus

The management of enteral feeds in preterm infants with a hemodynamically significant patent ductus arteriosus (hs-PDA) is a major challenge for neonatologists due to the fear of gastrointestinal (GI) complications. This review aims to analyze the available evidence on the complex relation between the presence and management of PDA, enteral feeding practices, and GI outcomes in the preterm population. There is limited evidence, based on small and heterogeneous trials, that hs-PDA may affect the splanchnic hemodynamic response to enteral feeds. While the presence of PDA seems a risk factor for adverse GI outcomes, the benefits of feeding withholding during pharmacological PDA treatment are controversial. The lack of robust evidence in support of or against a timely feeding introduction or feeding withholding during pharmacological PDA closure in preterm neonates does not allow to draw any related recommendation. While waiting for further data, the feeding management of this population should be carefully evaluated and possibly individualized on the basis of the infants’ hemodynamic and clinical characteristics. Large, multicentric trials would help to better clarify the physiological mechanisms underlying the development of gut hypoperfusion, and to evaluate the impact of enteral feeds on splanchnic hemodynamics in relation to PDA features and treatment.

Early prediction of spontaneous Patent Ductus Arteriosus (PDA) closure and PDA-associated outcomes: a prospective cohort investigation

BACKGROUND

Patent ductus arteriosus (PDA), the most commonly diagnosed cardiovascular condition in preterm infants, is associated with increased mortality and harmful long-term outcomes (chronic lung disease, neurodevelopmental delay). Although pharmacologic and/or interventional treatments to close PDA likely benefit some infants, widespread routine treatment of all preterm infants with PDA may not improve outcomes. Most PDAs close spontaneously by 44-weeks postmenstrual age; treatment is increasingly controversial, varying markedly between institutions and providers. Because treatment detriments may outweigh benefits, especially in infants destined for early, spontaneous PDA closure, the relevant unanswered clinical question is not whether to treat all preterm infants with PDA, but whom to treat (and when). Clinicians cannot currently predict in the first month which infants are at highest risk for persistent PDA, nor which combination of clinical risk factors, echocardiographic measurements, and biomarkers best predict PDA-associated harm.

METHODS

Prospective cohort of untreated infants with PDA (n=450) will be used to predict spontaneous ductal closure timing. Clinical measures, serum (brain natriuretic peptide, N-terminal pro-brain natriuretic peptide) and urine (neutrophil gelatinase-associated lipocalin, heart-type fatty acid-binding protein) biomarkers, and echocardiographic variables collected during each of first 4 postnatal weeks will be analyzed to identify those associated with long-term impairment. Myocardial deformation imaging and tissue Doppler imaging, innovative echocardiographic techniques, will facilitate quantitative evaluation of myocardial performance. Aim1 will estimate probability of spontaneous PDA closure and predict timing of ductal closure using echocardiographic, biomarker, and clinical predictors. Aim2 will specify which echocardiographic predictors and biomarkers are associated with mortality and respiratory illness severity at 36-weeks postmenstrual age. Aim3 will identify which echocardiographic predictors and biomarkers are associated with 22 to 26-month neurodevelopmental delay. Models will be validated in a separate cohort of infants (n=225) enrolled subsequent to primary study cohort.

DISCUSSION

The current study will make significant contributions to scientific knowledge and effective PDA management. Study results will reduce unnecessary and harmful overtreatment of infants with a high probability of early spontaneous PDA closure and facilitate development of outcomes-focused trials to examine effectiveness of PDA closure in "high-risk" infants most likely to receive benefit.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03782610. Registered 20 December 2018.

Complications associated with the current sequential pharmacological management of early postnatal hypotension in extremely premature infants

Early postnatal hypotension in premature infants is treated with escalating doses of vasopressor-inotropes (VI), followed by hydrocortisone if VI therapy fails. The adverse effects of this standard clinical practice have not been well reported. In a retrospective case-control study, we compared the complications associated with VI and hydrocortisone (HCVI) treatments in extremely low-birth-weight infants (≤1000 g) with contemporaneous normotensive medication-naïve controls via standard univariate and multivariate analyses. Birth weight, gestational age, and receipt of antenatal steroids did not differ between VI (n = 74) and control (n = 124) groups, while the occurrence of gestational diabetes mellitus and risks for patent ductus arteriosus, intraventricular-periventricular hemorrhage, spontaneous intestinal perforation, ventriculomegaly, and bronchopulmonary dsyplasia were higher in VI. Infants in the HCVI group (n = 69) had lower birth weight, gestational age, and receipt of antenatal steroids and higher risks for intraventricular-periventricular hemorrhage, bronchopulmonary dysplasia, air leaks, and patent ductus arteriosus than controls. Whereas the occurrences of spontaneous intestinal perforation, ventriculomegaly, and maternal diabetes mellitus did not differ, that of maternal hypertension trended to be lower in HCVI recipients (P = 0.06). In conclusion, hypotensive extremely low-birth-weight infants treated with VI or with HCVI are susceptible to intraventricular-periventricular hemorrhage, bronchopulmonary dysplasia, and patent ductus arteriosus. Furthermore, those who receive inotropes are at risk for spontaneous intestinal perforation and ventriculomegaly. Maternal diabetes mellitus increases the occurrence of hypotension, which responds to VI. Maternal hypertension does not contribute to VI responsive and tends to decrease the occurrence of VI-refractory hypotension.

[Abdominal surgery in premature infants with patent ductus arteriosus]

INTRODUCTION

Patent ductus arteriosus (PDA) is considered a risk factor for necrotising enterocolitis (NEC) and other gastrointestinal complications in preterm infants. The aim of this study is to determine whether there is a higher incidence of abdominal surgery and the associated morbidity and mortality in preterm infants who require treatment due to a significant PDA.

METHODS

An observational study was conducted that included preterm infants with <37 weeks of gestational age, and a diagnosis of PDA in the last 10 years. Depending on the treatment received, the patients were divided into 3 groups: medical (A), medical and surgical (B), and no treatment (C). An analysis was performed on the pre- and peri-natal variables, as well as the incidence of gastrointestinal complications (NEC, and need for surgery for this reason), and overall mortality.

RESULTS

The study included a sample of 144 patients, of whom 91 were assigned to group A, 16 to B, and 37 to C. The mean gestational age by groups was 28, 26.7, and 30.1 weeks, respectively. The mean birth weight was 1083.9 gr, 909.3 gr, and 1471.2 gr, respectively. As regards the incidence of NEC, a total of 21, 5, and 5 cases, respectively, were found in each group, with 43%, 60% and 35%, respectively requiring abdominal surgery. Mortality by groups was 12%, 19%, and 3%, respectively CONCLUSION: Patients who required treatment for a significant PDA had a higher incidence of gastrointestinal complications and higher mortality than untreated patients, with no statistically significant differences being found. In the group of patients that required treatment, lower gestational age and birth weight, could explain the increase in morbidity and mortality found in these patients.

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.

Risk factors and prevention for surgical intestinal disorders in extremely low birth weight infants

PURPOSE

Surgical intestinal disorders (SID), such as necrotizing enterocolitis (NEC), focal intestinal perforation (FIP), and meconium-related ileus (MRI), are serious morbidities in extremely low birth weight (ELBW, birth weight <1000 g) infants. From 2010, we performed enteral antifungal prophylaxis (EAP) in ELBWI to prevent for SID. The aim of this study was to identify disease-specific risk factors and to evaluate the efficacy of prevention for SID in ELBW infants.

METHODS

A retrospective chart review of all consecutive patients between January 2006 and March 2015, which included 323 ELBW infants who were admitted to Shizuoka Children's Hospital, was conducted.

RESULTS

The number of infants with NEC, FIP, and MRI was 9, 12, and 13, respectively; 28 in 323 ELBW infants died. The control group defined the cases were not SID. In-hospital mortality was higher in infants with NEC relative to those in the control group. On logistic regression analysis, low gestational age and cardiac malformations were associated with increased risk of NEC. IUGR were associated with increased risk of MRI. EAP decreased risk of NEC and FIP. Low gestational weight and NEC were associated with increased risk of death.

CONCLUSION

Survival to hospital discharge after operation for NEC in ELBW infants remains poor. EAP decreased risk of NEC and FIP in ELBW infants.

Intestinal perforation in very preterm neonates: risk factors and outcomes

OBJECTIVE

To compare neonatal outcomes of preterm infants (born at <32 weeks' gestation) with focal/spontaneous intestinal perforation (SIP), necrotizing enterocolitis (NEC)-related perforation, NEC without perforation or no NEC/perforation.

STUDY DESIGN

Retrospective cohort study of 17,426 infants admitted to Canadian neonatal intensive care units during 2010 to 2013. The primary outcome was a composite of mortality or morbidity (bronchopulmonary dysplasia, severe retinopathy, periventricular leukomalacia or nosocomial infection). Association of intestinal perforation with neonatal outcome was evaluated using multivariate logistic regression.

RESULT

SIP was present in 178 (1.0%) infants, NEC-related perforation in 246 (1.4%) and NEC without perforation in 538 (3.1%). Any intestinal perforation was associated with higher odds of the composite outcome (adjusted odds ratio (AOR): 8.21, 95% confidence interval (95% CI) 6.26 to 10.8); however, the odds were significantly lower for focal/SIP compared with NEC-related perforation (AOR: 0.29, 95% CI 0.17 to 0.51).

CONCLUSION

Of the two types of intestinal perforation, NEC-related perforation was associated with the highest risk of an adverse neonatal outcome.

Prophylactic indomethacin and intestinal perforation in extremely low birth weight infants

OBJECTIVE

Prophylactic indomethacin reduces severe intraventricular hemorrhage but may increase spontaneous intestinal perforation (SIP) in extremely low birth weight (ELBW) infants. Early feedings improve nutritional outcomes but may increase the risk of SIP. Despite their benefits, use of these therapies varies largely by physician preferences in part because of the concern for SIP.

METHODS

This was a cohort study of 15,751 ELBW infants in the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network from 1999 to 2010 who survived beyond 12 hours after birth. The risk of SIP was compared between groups of infants with and without exposure to prophylactic indomethacin and early feeding in unadjusted analyses and in analyses adjusted for center and for risks of SIP.

RESULTS

Among infants exposed to prophylactic indomethacin, the risk of SIP did not differ between the indomethacin/early-feeding group compared with the indomethacin/no-early-feeding group (adjusted relative risk [RR] 0.74, 95% confidence interval [CI] 0.49-1.11). The risk of SIP was lower in the indomethacin/early-feeding group compared with the no indomethacin/no-early-feeding group (adjusted RR 0.58, 95% CI 0.37-0.90, P = .0159). Among infants not exposed to indomethacin, early feeding was associated with a lower risk of SIP compared with the no early feeding group (adjusted RR 0.53, 95% CI 0.36-0.777, P = .0011).

CONCLUSIONS

The combined or individual use of prophylactic indomethacin and early feeding was not associated with an increased risk of SIP in ELBW infants.

Mortality associated with laparotomy-confirmed neonatal spontaneous intestinal perforation: a prospective 5-year multicenter analysis

BACKGROUND

Spontaneous intestinal perforation (SIP) has been recognized as a distinct disease entity. This study sought to quantify mortality associated with laparotomy-confirmed SIP and to compare it to mortality of laparotomy-confirmed necrotizing enterocolitis (NEC).

METHODS

Data were prospectively collected on 177,618 very-low-birth-weight (VLBW, 401-1500g) neonates born between January 2006 and December 2010 admitted to US hospitals participating in the Vermont Oxford Network (VON). SIP was defined at laparotomy as a focal perforation of the intestine without features suggestive of NEC or other intestinal abnormalities. The primary outcome was in-hospital mortality.

RESULTS

At laparotomy, 2036 (1.1%) neonates were diagnosed with SIP and 4076 (2.3%) with NEC. Neonates with laparotomy-confirmed SIP had higher mortality (19%) than infants without NEC or SIP (5%, P=0.003). However, laparotomy-confirmed SIP patients had significantly lower mortality than those with confirmed NEC (38%, P<0.0001). Mortality in both NEC and SIP groups decreased with increasing birth weight and mortality was significantly higher for NEC than SIP in each birth weight category. Indomethacin and steroid exposure were more frequent in the SIP cohort than the other two groups (P<0.001).

CONCLUSIONS

In VLBW infants, the presence of laparotomy-confirmed SIP increases mortality significantly. However, laparotomy-confirmed NEC mortality was double that of SIP. This relationship is evident regardless of birth weight. The variant mortality of laparotomy-confirmed SIP versus laparotomy-confirmed NEC highlights the importance of differentiating between these two diseases both for clinical and research purposes.

Intestinal muscularis propria increases in thickness with corrected gestational age and is focally attenuated in patients with isolated intestinal perforations

PURPOSE

Intestinal perforations are common in premature infants, leading to a diagnostic dilemma between necrotizing enterocolitis and isolated intestinal perforation (IIP). IIP is thought to result from a congenital or acquired absence of the muscularis propria. However, developmental events leading to IIP are not well understood. This study examines the relationship between corrected gestational age (CGA) and intestinal muscle development in controls and patients with IIP.

METHODS

Specimens from stillbirths and infants undergoing intestinal surgery from 8 to 48weeks' CGA were collected from 2005 to 2012. Twelve patients with IIP were identified. Control specimens were collected during 25 fetal autopsies and 39 bowel resections. In each case, three sections of intestine were examined histologically for muscularis mucosa, circular and longitudinal muscle thickness. Comparisons of control and perforated specimens were performed via linear regression and ANOVA.

RESULTS

Controls and adjacent normal segments in IIP showed a linear relationship between thickness of circular and longitudinal muscles with CGA. Circular and longitudinal muscles were thinner in perforated segments than in adjacent normals and CGA-matched controls (p<0.05).

CONCLUSION

Intestinal muscularis propria increases in thickness with CGA. Muscle thickness is focally attenuated in patients with isolated intestinal perforations, while the remaining intestine is normal, suggesting that primary repair is an appropriate treatment.

Patent ductus arteriosus in preterm infants: do we have the right answers?

Patent ductus arteriosus (PDA) is a common clinical condition in preterm infants. Preterm newborns with PDA are at greater risk for several morbidities, including higher rates of bronchopulmonary dysplasia (BPD), decreased perfusion of vital organs, and mortality. Therefore, cyclooxygenase (COX) inhibitors and surgical interventions for ligation of PDA are widely used. However, these interventions were reported to be associated with side effects. In the absence of clear restricted rules for application of these interventions, different strategies are adopted by neonatologists. Three different approaches have been investigated including prophylactic treatment shortly after birth irrespective of the state of PDA, presymptomatic treatment using echocardiography at variable postnatal ages to select infants for treatment prior to the duct becoming clinically significant, and symptomatic treatment once PDA becomes clinically apparent or hemodynamically significant. Future appropriately designed randomized controlled trials (RCTs) to refine selection of patients for medical and surgical treatments should be conducted. Waiting for new evidence, it seems wise to employ available clinical and echocardiographic parameters of a hemodynamically significant (HS) PDA to select patients who are candidates for medical treatment. Surgical ligation of PDA could be used as a back-up tool for those patients who failed medical treatment and continued to have hemodynamic compromise.

Intestinal perforation in very-low-birth-weight infants with necrotizing enterocolitis

PURPOSE

To identify risk factors for intestinal perforation in very-low-birth-weight (VLBW) infants with necrotizing enterocolitis (NEC).

METHODS

Retrospective case-control study over a 10-year period, using univariate and multivariate logistic regression analyses to compare all VLBW infants treated for perforated NEC, with two age and weight-matched groups: infants with non-perforated NEC and infants without NEC.

RESULTS

Twenty infants with perforated NEC were matched to 20 infants with non-perforated NEC and 38 infants without NEC. Infants with perforated NEC were younger (p<0.01) and had higher rates of abdominal distention, metabolic acidosis, hyperglycemia and elevated liver enzymes (p<0.05). On logistic regression analysis, abdominal distention was associated with an increased risk of intestinal perforation (OR 39.8, 95% CI 2.71-585) and late onset of NEC (one-day increments) was associated with a decreased risk (OR 0.93, 95% CI 0.87-1.0).

CONCLUSION

Identification of abdominal distention at an early age in VLBW infants should lead to increased vigilance for signs of perforated NEC and may enable early intervention.

Spontaneous intestinal perforation in extremely low birth weight infants: association with indometacin therapy and effects on neurodevelopmental outcomes at 18-22 months corrected age

BACKGROUND

Spontaneous intestinal perforation (SIP) is associated with the use of postnatal glucocorticoids and indometacin in extremely low birth weight (ELBW) infants. The authors hypothesised: 1) an association of SIP with the use of antenatal steroids (ANS) and indometacin either as prophylaxis for intraventricular hemorrhage (IVH) (P Indo) or for treatment of PDA (Indo/PDA) and 2) an increased risk of death or abnormal neurodevelopmental outcomes in infants with SIP at 18-22 months corrected age.

DESIGN/METHODS

The authors retrospectively identified ELBW infants with SIP in the Neonatal Research Network's generic database. Unadjusted analysis identified the differences in maternal, neonatal and clinical variables between infants with and without SIP. Logistic regression analysis identified the adjusted OR for SIP with reference to ANS, P Indo and Indo/PDA. Neurodevelopmental outcomes were assessed among survivors at 18-22 months corrected age.

RESULTS

Indo/PDA was associated with an increased risk of SIP (adjusted OR 1.61; 95% CI 1.25 to 2.08), while P Indo and ANS were not. SIP was independently associated with an increased risk of death or neurodevelopmental impairment (NDI) (adjusted OR 1.85; 95% CI 1.32 to 2.60) and NDI among survivors (adjusted OR 1.75, 95% CI 1.20 to 2.55).

CONCLUSION

Indometacin used for IVH prophylaxis and ANS were not associated with the occurrence of SIP in ELBW infants. Indometacin used for treatment of symptomatic PDA was however associated with an increased risk of SIP. ELBW infants with SIP have an increased risk of poor neurodevelopmental outcomes.

Learning to live with patency of the ductus arteriosus in preterm infants

Treatment of persistent patency of the ductus arteriosus in preterm infants remains heterogeneous and controversial. Routine early treatment to induce ductal closure is not beneficial, but the potential criteria for, timing of, methods for and benefits of later ductal closure have not been determined. Management strategies for infants awaiting spontaneous closure or meeting criteria for treatment may be based on pathophysiological considerations but require evaluation in clinical trials. Better diagnostic tools allowing the identification of infants who might benefit from ductal closure, supplemented by data from clinical trials confirming realization of that potential, are urgently needed.

Obstetrical risk factors for focal intestinal perforation in very low birth weight infants

OBJECTIVE

Our objective was to determine the obstetrical risk for spontaneous focal intestinal perforation (FIP) in very low birth weight (VLBW) infants.

METHODS

Eight mothers delivered infants who underwent laparotomy for FIP between 2001 and 2006 in our hospital. A retrospective case-control study of the eight case mothers and 32 control mothers was conducted. Clinical findings were retrospectively analyzed.

RESULTS

There were significant differences in the frequency of oligohydramnios (P<0.01) and velamentous cord insertion (P<0.05) between cases and controls. The 1-min Apgar score was significantly lower in the FIP group than in the control group (P<0.05). Moreover, primigravidity was significantly associated with a risk of FIP.

CONCLUSIONS

The etiology of FIP may be related to changes in the blood circulation, such as fetal hypoxic-ischemic episodes or disturbance in the umbilical blood flow, during the antepartum and/or intrapartum periods.

Patent ductus arteriosus in the preterm infant: to treat or not to treat?

Pharmacological and/or surgical closure of a hemodynamically significant patent ductus arteriosus (PDA) in the very preterm infant has been the standard of care over the past few decades. However, the rationale for closure of PDA has recently been challenged. In this article, the factors that have fueled the controversy of the approach to the management of PDA and the gap in our knowledge are reviewed in detail. In addition, the pros and cons of the different treatment strategies applied in clinical care are evaluated with a focus on discussing the available evidence in the literature.

Spontaneous intestinal perforation

So much is unknown about SIP-its etiology, pathophysiology, best treatment modality, and outcome. Yet the incidence of SIP is increasing as more VLBW infants are surviving and since SIP has been identified as a separate disease from NEC. Because many cases present with an insidious onset, it is imperative that practitioners review all x-rays with SIP in mind. Although SIP is a relatively rare occurrence in the NICU, its potential to increase morbidity and mortality in premature infants warrants further research to improve outcomes.

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.