Neonatal paroxetine withdrawal syndrome

Four term neonates presented with symptoms such as jitteriness and necrotising enterocolitis after paroxetine exposure in utero.

Necrotizing enterocolitis in the full-term neonate

Necrotizing enterocolitis (NEC) is a relatively common disorder of multifactorial aetiology that primarily affects preterm newborns, but has been reported to occur in the full-term neonate as well. This review focuses on known and recent developments in the epidemiology, pathogenesis, diagnosis, management and prevention of NEC in the full-term neonate.

A regional study of underlying congenital diseases in term neonates with necrotizing enterocolitis

AIM OF THE STUDY

The aetiology of necrotizing enterocolitis (NEC) remains poorly understood in infants of all gestation, particularly when it occurs at term. We hypothesize that NEC in term infants is rare but often associated with underlying congenital illnesses.

METHOD

Records of all term infants hospitalized with radiologically or surgically proven NEC in the 10 tertiary centres of two geographical regions of Australia during a 6.5-y period were reviewed. Regional birth data were obtained and a special care nursery survey was conducted.

RESULTS

Twenty-nine infants had proven NEC giving a population incidence of 0.05 per 1000 live births. Nineteen (66%) of them had underlying congenital diseases. Five (17%) infants had endocrine disorders, which included panhypopituitarism, hypothyroidism, hypoparathyroidism and congenital adrenal hyperplasia. Ten infants had congenital heart disease, eight being cyanotic. Six of them developed NEC prior to any invasive cardiac procedures. Seven of the other nine infants without any congenital diseases had perinatal risk factors associated with NEC. The severity of illness was not different amongst the three groups. All infants, except two, survived.

CONCLUSION

NEC in term infants is commonly secondary to or preceded by underlying congenital diseases. A considerable proportion of NEC cases had co-existing endocrine illnesses.

Graft failure secondary to necrotizing enterocolitis in multi-visceral transplantation recipients: two case reports

We report on two recipients of multi-visceral grafts who exhibited sudden onset of acute abdomen discomfort 2 weeks post-transplantation after a fairly uneventful immediate post-operative course. Both patients were shown to have pneumatosis intestinalis and one had air in the portal vein. Both patients underwent exploration, which showed non-viable intestine (terminal ileum and colon in the first patient and the entire small intestine distal to the ligament of Treitz in the second patient). There was no vascular thrombosis. The necrotic intestine was resected in both cases. The first patient developed sepsis and died 15 days later despite the rescue efforts. The second patient was re-transplanted twice and is doing well. The histopathology of the segments involved revealed cryptitis, vasculitis, and features of transmural necrosis. Accordingly, both clinical and pathologic features are diagnostic of necrotizing enterocolitis. To our knowledge this is the first report of this complication following intestinal or multi-visceral transplantation.

A case report on the perinatal management of a 30-week preterm baby with congenital complete heart block

INTRODUCTION

Congenital complete heart block is an uncommon condition in the newborn, but is known to occur with maternal systemic lupus erythematosus.

CLINICAL PICTURE

This paper presents one such baby with complete heart block who was born premature (after a gestation of 30 weeks) and weighing 759 g.

TREATMENT

Continuous isoprnaline infusion was initially used to support the baby while her other neonatal problems were treated. A Medtronics VV1 pacemaker was subsequently inserted to maintain a heart rate that would be more physiologically acceptable for the patient.

OUTCOME

This baby is currently thriving well, having been followed up for one year.

CONCLUSIONS

The management issues, encompassing maternal and neonatal problems, and a review of current literature on this condition are discussed.

Inflammation in the developing human intestine: A possible pathophysiologic contribution to necrotizing enterocolitis

Necrotizing enterocolitis (NEC), a major cause of morbidity and mortality in premature infants, occurs after the introduction of oral feedings in conjunction with initial bacterial colonization of the gut and is hypothesized to be due to an immature (inappropriate) enterocyte response to bacterial stimuli. To test this hypothesis, we compared the enterocyte IL-8 response to inflammatory stimuli [lipopolysaccharide (LPS) and IL-1beta] in immature vs. mature human small intestine. Initial in vitro studies comparing confluent Caco-2 cells, a model for mature human enterocytes, with a primary human fetal intestinal cell line (H4 cells) demonstrated that after inflammatory stimulation fetal cells secreted more IL-8 (LPS, 8-fold; IL-1beta, 20-fold) than Caco-2 cells. IL-8 mRNA activity in fetal compared to Caco-2 cells was proportionately increased by the same magnitude with both stimuli. To validate the in vitro observations, small intestinal organ cultures from fetuses vs. older children were exposed to LPS and IL-1beta. Again in human organ cultures from fetuses compared to older children, IL-8 secretion was greater (LPS, 2.5-fold; IL-1beta, 200-fold) and mRNA activity after stimulation was comparably higher, suggesting that increased transcription of the IL-8 gene may account for the excessive response. Using immunohistochemical staining to identify the cellular source of IL-8, activity was noted predominantly in villous and crypt epithelium but also in a few immunoresponsive lymphoid cells. The observation that immature human enterocytes react with excessive pro-inflammatory cytokine production after inflammatory stimulation may help in part explain why prematures exposed to initial colonizing bacteria develop necrotizing enterocolitis.

A cluster of necrotizing enterocolitis in term infants undergoing open heart surgery

BACKGROUND

Necrotizing enterocolitis (NEC) is a serious gastrointestinal disease of unknown cause that predominantly affects premature infants, but it has been reported in term infants with congenital heart disease.

METHODS

In August and September of 1997, 4 cases of NEC in term infants with congenital heart disease were identified among 24 infants undergoing cardiac surgical procedures at our institution. Because nosocomial NEC had not previously been identified among infants in our pediatric intensive care unit, a case-control study was conducted to identify risk factors for NEC. All infants less than 4 months old undergoing cardiac surgery without development of NEC during the epidemic period were selected as controls.

RESULTS

The only significant risk factor associated with case-infants was a higher mean temperature gradient (rectal/toe) during the immediate 12-hour postoperative period (4.0 degrees C vs 2.0 degrees C, P <.01). Urine output was higher in control-infants in this postoperative period, although not statistically significant (11.9 mL/h vs 6.1 mL/h, P =.15).

CONCLUSION

Although an infectious etiology cannot be ruled out, the cases of NEC in infants with congenital heart disease after cardiac procedures may have resulted from mesenteric ischemia associated with a low perfusion state in the perioperative period.

Perinatal indomethacin treatment and neonatal complications in preterm infants

To evaluate the incidence of neonatal complications among infants exposed to indomethacin antenatally, postnatally or both ante-and postnatally (combined), the records of 240 infants of gestational ages between 23 to 32 weeks were analysed retrospectively. Antenatal indomethacin treatment for longer than 2 days with a daily or cumulative dosage >/=150 mg correlated with a significantly higher incidence of grade I-II intraventricular haemorrhage. Combined exposure, cumulative antenatal exposure >/=150 mg and duration of antenatal exposure of more than 2 days was associated with necrotising enterocolitis and a cumulative exposure with sepsis. There was no independent association between indomethacin exposure and pneumothorax, bronchopulmonary dysplasia or respiratory distress syndrome.

CONCLUSION

Preterm infants with exposure to antenatal indomethacin might be at increased risk of grade I and II intraventricular haemorrhage and those with both ante- and postnatal exposure at an increased risk of necrotising enterocolitis and sepsis.

The incidence of necrotizing enterocolitis after introducing standardized feeding schedules for infants between 1250 and 2500 grams and less than 35 weeks of gestation

OBJECTIVE

To evaluate the incidence of necrotizing enterocolitis (NEC) after implementing standardized feeding schedules.

METHOD

This was a cohort study, which retrospectively reviewed the incidence of NEC for a 3-year period before implementing feeding schedules and prospectively evaluated the incidence of NEC for a 3-year period after implementing feeding schedules in infants with birth weights between 1250 and 2500 g and <35 weeks' gestation. The feeding schedules were comprised of 3 parts. First, no group was fed within the first 24 hours of life. Feeds were started between 24 to 72 hours of life based on birth weight. Second, the initial feed was full-strength breast milk or half-strength formula. Half-strength formula was changed to full-strength formula on the fourth day for all groups. Third, the daily feeding volume increase was no greater than 20 mL/kg for all groups.

RESULTS

In the 477 infants before the feeding schedules, there were 23 (4.8%) cases of definite NEC defined as pneumatosis on abdominal film or NEC confirmed at the time of surgery, and in the 466 infants after the feeding schedules, there were 5 (1.1%) cases of NEC. Before the feeding schedules, those who developed NEC started feeds sooner 1.5 +/- 1.5 (+/- standard deviation [SD]) days versus 3.0 +/-.7 (+/-SD) days, reached full feeds sooner 4.0 +/- 1.8 (+/- SD) days versus 9.8 +/-.5 (+/-SD) days and were more likely to have been started on formula than those who developed NEC after implementing the feeding schedules. The mean time for NEC to occur after the feeding schedules increased from 5.9 +/- 4.1 (+/-SD) days to 19.4 +/- 16.3 (+/- SD) days, although not statistically significant. The number of mothers who received prenatal steroids increased after the feeding schedules. The number of infants with NEC, however, significantly decreased whether their mothers were pretreated with steroids. The risk of NEC was reduced 84% after the introduction of feeding schedules as determined by multiple logistic regression analysis and adjusting for confounding by birth weight, white race, prenatal steroid exposure, day of life of first feed, day of life to reach full feeds, and breast milk.

CONCLUSION

The incidence of NEC was significantly decreased after the implementation of standardized feeding schedules, which was independent of birth weight, prenatal steroid exposure, breast milk, day of life of first feed, and the number of days to reach full feeds.

Adverse host responses to bacterial toxins in human infants

Bacterial toxin interaction with the intestinal epithelium is regulated developmentally as well as by nutritional factors. It is the binding of bacterial toxins to the epithelium followed by several events that forms the basis of infantile diarrhea, a leading cause of morbidity and mortality world-wide. There has been increasing interest in bacterial toxin interaction with the enterocyte, postreceptor events that follow and the effect of developmental regulation on necrotizing enterocolitis. Diet and environmental factors can provide a major influence on bacterial-enterocyte interaction. Particularly important is the role of breast milk and its constituents, as well as probiotics, in this regard. The purpose of this review is to provide a brief overview on this complex interaction.

[Trophic feeding of very low birth weight infants]

The author presents current views on early trophic feeding of very low birth weight infants. Trophic feeding does not increase the risk of necrotizing enterocolitis, but sustains structural intestinal integrity, promotes maturation of gastrointestinal tract and decreases the complications of parenteral nutrition. Principles of initiating enteral feeding, contraindications and the most common problems accompanying enteral feeding were presented.

Maternal cocaine abuse resulting in necrotizing enterocolitis. An experimental study in a rat model. II. Results of perfusion studies

During the last decade, several publications have appeared associating the maternal use of cocaine and subsequent development of necrotizing enterocolitis (NEC). In 1994, the effects of cocaine in pregnant rats had been reported by this group: a significant decrease in the number of live births, mean birth weight and mean placental weight. In addition, histopathologic examinations revealed severe inflammation and degenerative vascular changes in the uterus and placenta. Severe histopathologic changes resembling NEC such as focal necrosis, necrobiosis, and hemorrhagic inflammatory changes in the gastrointestinal tract of the embryos were also reported. The aim of the second part of this study was to assess the hemodynamic effects of cocaine HCI in pregnant rats and the results of perfusion studies in the uterus, placenta, and fetuses to determine a relation between the dose of drug, hemodynamic changes, and degree of histopathologic findings. Forty-seven Wistar albino rats and 91 rat fetuses were studied: group A (pregnant rats), 16 rats and 91 rat fetuses, group B (nonpregnant rats), 31 rats. Each group was divided into subgroups of cocaine-abused and non-cocaine-abused rats. In each group 2-3 mCi technetium Tc-99m methoxyisobutyl-isonitryl (Sesta MIBI) was injected into the tail vein. Radioactivity counts per g tissue (cps/g) in the uterus, placenta, and fetus were assessed by gamma counter. Cocaine 75 mg/kg per day severely decreased the perfusion of the uterus, placenta, and fetuses. These impairments were statistically significant. In lower doses (30-50 mg/kg per day) no statistically significant changes were observed in the perfusion of the uterus and placenta, but a significant decrease in fetal perfusion was seen. In group B, no significant changes in the perfusion of the uterus due to cocaine were seen. Thus, maternal cocaine abuse results in a reduction in perfusion of the uterus, placenta, and fetus. There was a dose-dependent correlation between the perfusion changes and the development of NEC-like histopathologic changes: the higher the cocaine dose received by the mother, the higher the level of placental and fetal injury. We suggest that perinatal cocaine exposure should be considered a high risk for development of NEC in rat fetuses and embryos. For this reason, infants with a history of possible maternal cocaine abuse or positive urinary cocaine metabolites have to be followed very carefully for NEC.

Morbidity and mortality among very-low-birth-weight neonates with intrauterine growth restriction. The Vermont Oxford Network

OBJECTIVE

We sought to determine the associations between intrauterine growth restriction and neonatal morbidity and mortality, as well as the impact of prenatal glucocorticoid administration on the frequency of specific complications of prematurity among neonates with intrauterine growth restriction.

STUDY DESIGN

We examined the association between intrauterine growth restriction and adverse neonatal outcomes in a population of 19,759 singleton very-low-birth-weight neonates without major birth defects. We included neonates from 25 to 30 weeks' gestation entered in the Vermont Oxford Network database between 1991 and 1996 by 196 institutions. Intrauterine growth restriction was defined as the 10th percentile for birth weight according to the 1993 US national statistics. Odds ratios were estimated according to stepwise logistic regression for each neonatal outcome. Potential explanatory variables included gestational age, intrauterine growth restriction, race, prenatal care, prenatal glucocorticoid administration, route of delivery, fetal sex, and birth within versus postnatal transfer to a network institution.

RESULTS

There was a statistically significant association of intrauterine growth restriction with neonatal death (odds ratio, 2.77; 95% confidence interval, 2.31-3. 33), necrotizing enterocolitis (odds ratio, 1.27; 95% confidence interval, 1.05-1.53), and respiratory distress syndrome (odds ratio, 1.19; 95% confidence interval, 1.03-1.36). There was a trend (P <. 10) toward association of intrauterine growth restriction with increased risks of intraventricular hemorrhage (odds ratio, 1.13; 95% confidence interval, 0.99-1.29) and severe intraventricular hemorrhage (grades III and IV; odds ratio, 1.25; 95% confidence interval, 0.98-1.59). Maternal prenatal glucocorticoid administration was associated with significantly lower risks of respiratory distress syndrome (odds ratio, 0.51; 95% confidence interval, 0.44-0.58), intraventricular hemorrhage (odds ratio, 0.67; 95% confidence interval, 0.61-0.73), severe intraventricular hemorrhage (odds ratio, 0.50; 95% confidence interval, 0.43-0.57), and death (odds ratio, 0.54; 95% confidence interval, 0.48-0.62). The benefits of prenatal glucocorticoid therapy for growth-restricted newborns were similar to those among normally grown infants.

CONCLUSIONS

Intrauterine growth restriction within the range of 501 to 1500 g birth weight is associated with increased risks of neonatal death, necrotizing enterocolitis, and respiratory distress syndrome. Prenatal corticosteroid use was associated with decreased risks of all outcomes studied except necrotizing enterocolitis. We found no evidence that this benefit was dependent on fetal size.

[Necrotizing enterocolitis (NEC) in the newborn]

Necrotizing enterocolitis (NEC) is a disease of the premature neonate that requires early therapy, sometimes even surgery and therefore early diagnosis. In general, plain radiography of the abdomen and sonography are valuable imaging techniques for diagnosis of NEC.

COURSE OF NEC

The disease starts with distension of small bowel loops. Furthermore the children develop pneumatosis in the bowel wall, which is a nonspecific pattern. If the NEC persists, the air passes into the portal vein system, causing a pneumoportogram. Finally, the disease can lead to perforation. In doubtful cases, the plain radiogram must be repeated within a period of 6 h. With sonography distension of the bowel, thickening of and pneumatosis in the bowel wall, the pneumoportogram and free intraperitoneal fluid can be easily depicted. The most common complications of NEC are intestinal stenosis and strictures that can lead to ileus.

DIFFERENTIAL DIAGNOSIS

Focal perforation of ileum, volvulus and Hirschsprung's disease are some of the differential diagnoses.

Necrotizing enterocolitis in infants born to women with severe early preeclampsia and absent end-diastolic umbilical artery doppler flow velocity waveforms

The aim of this study was to determine the prevalence of necrotizing enterocolitis (NEC) in infants born to a homogeneous group of women with severe preeclampsia before 34 weeks' gestation and who had absent end-diastolic umbilical artery Doppler flow (AEDF) or normal umbilical Doppler flow velocities (NUFV). A total of 242 infants were entered into the study. The mean birth weight was 1260.5 g (SD = 339) and the mean gestational age 30.5 weeks (SD = 2.0). Sixty-eight (28%) infants had AEDF, 43 (18%) had umbilical artery Doppler flow velocities between the 95th and 99th percentile, and 131 (54%) had NUFV. Forty-one (18%) infants developed NEC, of whom 20 (8%) developed definite and advanced NEC (grade 2 and 3). Of these, 16(80%) had grade 2 and 4(20%) had grade 3. Twenty-one (8%) infants developed suspected NEC (grade 1). The mean onset of grade 1 NEC (7.2 days) occurred significantly earlier than in those with grades 2 and 3 NEC (18.7 and 23.3 days, respectively). Of the 21 infants with grade 1 NEC, 10 (48%) had AEDF and 9 (43%) had NUFV. None of the infants with grades 2 or 3 NEC had AEDF. We conclude that although chronically hypoxemic fetuses born to women with severe early onset preeclampsia and AEDF respond by redistributing blood flow to vital organs and away from the gut; the intestinal compromise is of insufficient magnitude to induce intestinal necrosis or NEC. Enteral feeding, however, should be introduced cautiously in infants with AEDF, as so-called suspected NEC developed significantly more often in these infants.

The radiology of necrotizing enterocolitis

This article reviews the radiology of necrotizing entercolitis (NEC), with an emphasis on the sensitivity and specificity of the typical plain film findings. An approach to radiologic diagnosis is suggested. The more recently described entity of perforation without NEC also is described.

Necrotizing enterocolitis: pathophysiology and prevention

Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency in the neonatal intensive care unit. It is a disease of medical progress in that more very low-birth-weight neonates are surviving than ever before and are thus susceptible to this potentially devastating disease. NEC received very little attention in the literature before the 1970s but now is well known to all neonatologists and pediatric surgeons. The 1500 to 2000 infants that die every year from this disease in the United States and the large number of infants who develop short gut syndrome from this disease only represent the tip of the iceberg of the problems NEC causes. The widespread fear of NEC among neonatologists and pediatric surgeons has contributed in large part to the use of the IV route rather than the gastrointestinal tract for nourishing these infants for relatively long periods. The consequences of this include a high incidence of sepsis, high hospital costs, and potential long-term neurodevelopmental disability because of poor nutrition during a very vulnerable period of growth and development. The purpose of this review is to provide a brief overview of the clinical presentation and current treatment for NEC, then provide a discussion of the pathophysiology on which strategies for prevention can be formulated.

Necrotizing enterocolitis in omphalopagus conjoined twins

Female omphalopagus twins underwent laparotomy on the second day of life after an antenatally diagnosed high jejunal bowel obstruction. Bowel resection and choldocho-enterostomies were performed. Despite recovery from laparotomy, the development of severe necrotizing enterocolitis (NEC) in one twin led to rapid deterioration and the death of both infants on day 34. The elucidation of the combined biliary tree, the dilemma of NEC in conjoined twins, and the possibilities of emergency separation are discussed. Consideration should be given to emergency separation of conjoined twins in the event of potentially lethal complications.

The physicochemical environment of the neonatal intestine

Dietary intake, bacterial metabolites, and the secretion of factors (eg, proteins, electrolytes, lipid-soluble molecules, and water) by the body each contribute to the physicochemical environment of the gastrointestinal tract. Peristalsis regulates the changes along the length of the intestine. However, coordinated peristaltic responses develop as premature infants mature. In addition, the physicochemical environment of the center of the intestinal lumen differs from that of the epithelial surface. The area adjacent to the small intestinal epithelium is more acid than the bulk phase. Na+/H+ exchange antiporters in the epithelial cell apical membrane generate this acidity. Mucus maintains the acid microclimate by preventing free diffusion of hydrogen ions into the bulk phase. Development also affects these mechanisms. Changes in the lumenal environment may alter the synthesis of signaling molecules expressed by the intestinal epithelium. Thus, the epithelium, through changes in gene regulation, may act as an active interface that transmits information about the composition of the intestinal lumen to the mucosal immune system. Premature neonates are at risk of necrotizing enterocolitis, a disease almost exclusively associated with oral feeds. The pathogenesis of this condition may, in part, be due to the immaturity of the interactions between the physicochemical environment of the lumen and intestine.

Delay of catch-up growth in very low birthweight infants

AIM

To determine if appropriate for gestational age, very low birth weight infants demonstrate catch-up growth.

METHODS

The notes of 74 appropriate for gestational age, very low birth weight infants were reviewed and anthropometric measures converted into standard deviation scores (Z-scores). The growth of "well" infants was compared with that of "unwell" infants (those who developed necrotising enterocolitis, bronchopulmonary dysplasia or were not feeding at one week of age).

RESULTS

All infants showed reduced weight (p<0.001) and head circumference (p<0.01) Z-scores at one week of age. This persisted until 35 weeks postmenstrual age in both groups, by which time length Z-scores had also reduced. The well group had regained birth Z-scores for all measurements by three months post-term. However the unwell group still had significantly lower weight (p<0.01) and length (p<0.05) Z-scores at three months.

CONCLUSIONS

Well very low birth weight infants regained their birth percentiles by three months post-term. In infants with significant neonatal illness, this recovery was delayed.

Necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is the most serious and frequently acquired gastrointestinal disorder in neonates. The pathogenesis of NEC is unknown, but it may result from a disturbance of the delicate balance among gastrointestinal perfusion, enteric organisms, and enteral feeding. Risk factors for NEC include prematurity, hypoxic-ischemic insult, and formula or breast milk feedings. The clinical spectrum of NEC is multifactoral and ranges from temperature instability, apnea, lethargy, abdominal distention, bilious residuals, and guaiac-positive stools to septic shock, disseminated intravascular coagulation, and death. Medical management is usually adequate treatment for NEC. Surgical treatment is considered if medical management is inadequate to control the spread of the disease. Health care team members must be constantly alert to the presentation of NEC. Expeditious treatment will positively influence the outcome of the disease.

Randomized trial of "slow" versus "fast" feed advancements on the incidence of necrotizing enterocolitis in very low birth weight infants

OBJECTIVE

To determine whether the rate of feed advancement affects the incidence of necrotizing enterocolitis (NEC).

STUDY DESIGN

Prospective randomized controlled trial involving 185 formula-fed infants with birth weight 501 to 1500 g and gestational age </=34 weeks. Infants were randomized into 2 groups: "slow" (n = 98), who received 15 cc/kg/d increments (a 10-day schedule to full feeds) and "fast" (n = 87), who received 35 cc/kg/d increments (a 5-day schedule to full feeds) of Similac Special Care 20 cal/oz. Feeds were increased only if well tolerated as defined by a protocol.

RESULTS

The incidence of NEC (Bell stage >/=II) was similar in both groups (slow 13% and fast 9%, P =.5). The incidence of perforation (Bell stage III) was also similar in both groups (slow 4% and fast 2%, P =.8). Feeds were started at a comparable postnatal age in both groups (median age: slow 5 days and fast 4 days, P =.9). Although the neonates in the fast group attained full enteral intake earlier (median days [25th and 75th percentiles]: slow 15 [12, 21] and fast 11 [8, 15], P <.001) and regained their birth weight earlier (slow 15 [11, 20] and fast 12 [8, 15], P <.05), their ages at discharge were not statistically different (slow 47 [31, 67] and fast 43 [29, 62], P =.3)

CONCLUSIONS

A greater than twofold difference in the rate of feed advancement from 15 cc/kg/d to 35 cc/kg/d did not affect the incidence of NEC >/= stage II. Factors other than feed advancement appear to be more important in the pathogenesis or progression of NEC.

Protective nutrients and bacterial colonization in the immature human gut

The normal human microflora is a complex ecosystem that is in part dependent on enteric nutrients for establishing colonization. The gut microbiota are important to the host with regard to metabolic functions and resistance to bacterial infections. At birth, bacterial colonization of a previously germ-free human gut begins. Diet and environmental conditions can influence this ecosystem. A breast-fed, full-term infant has a preferred intestine microbiota in which bifidobacteria predominate over potentially harmful bacteria, whereas in formula-fed infants, coliforms, enterococci, and bacteroides predominate. The pattern of bacterial colonization in the premature neonatal gut is different from that in the healthy, full-term infant gut. Those infants requiring intensive care acquire intestinal organisms slowly, and the establishment of bifidobacterial flora is retarded. A delayed bacterial colonization of the gut with a limited number of bacterial species tends to be virulent. Bacterial overgrowth is one of the major factors that promote bacterial translocation. The aberrant colonization of the premature infant may contribute to the development of necrotizing enterocolitis. Breast-feeding protects infants against infection. Oligo-saccharides and glycoconjugates, natural components in human milk, may prevent intestinal attachment of enteropathogens by acting as receptor homologues. Probiotics and prebiotics modulate the composition of the human intestinal microflora to the benefit of the host. These beneficial effects may result in the suppression of harmful microorganisms, the stimulation of bifidobacterial growth, or both. In the future, control and manipulation of the bacterial colonization in the neonatal gut may be a new approach to the prevention and treatment of intestinal infectious diseases of various etiologies.

Gastro-intestinal complications following neonatal cardiac catheterisation

BACKGROUND

Infants with congenital cyanotic heart disease are at increased risk of developing necrotising enterocolitis (NEC). We examined a cohort of infants with congenital cyanotic heart disease in order to assess the role of cardiac catheterisation in the pathogenesis of NEC.

METHODS

Sixty-five infants with congenital cyanotic heart disease were assessed in a retrospective study. The incidence of gastrointestinal complications was compared between infants who required cardiac catheterisation and those who did not.

RESULTS

There were 38 infants who required cardiac catheterisation and 27 who did not. Both groups were similar for known risk factors for NEC. Eleven of the catheterised infants developed bloody stools versus 4 of the non-catheterised infants (OR 2.34; 95% CI 0.65-8.36). Five of the catheterised infants developed classical NEC versus none of the non-catheterised infants (OR 4.24; 95% CI 0.47-38.5). Four of the five infants who developed NEC did so during re-introduction of feeds following cardiac catheterisation.

CONCLUSION

Infants with congenital cyanotic heart disease appear to be at a greater risk of gastrointestinal complications including necrotising enterocolitis in the days following cardiac catheterisation. We suggest a more cautious approach to feeding is required during this period.

Fulminant necrotizing enterocolitis in a premature neonate treated for supraventricular tachycardia

A premature neonate with supraventricular tachycardia was treated prenatally and postnatally, without significant signs of congestive heart failure. Enteral feeding was initiated after 48 hours of age. The infant developed fatal, fulminant necrotizing enterocolitis 28 hours after starting feeds.

Absence of lysozyme (muramidase) in the intestinal Paneth cells of newborn infants with necrotising enterocolitis

AIM

To determine immunocytochemically whether preterm and newborn infants with necrotising enterocolitis (NEC) show differences in numbers of lysozyme positive Paneth cells compared with normal controls, and to relate the findings to the possibility that lysozyme deficiency may facilitate the bacterial infections thought to be associated with this condition.

METHODS

Tissues from 10 infants with NEC and from 11 matched controls were sectioned and stained immunocytochemically for lysozyme. Differences in the numbers of Paneth cells and degree of lysozyme positivity in the tissues were assessed.

RESULTS

Tissues from NEC patients showed no, or very few, lysozyme positive Paneth cells, whereas controls showed strong positive staining.

CONCLUSIONS

A deficiency or developmental defect in Paneth cells, resulting in an absence of lysozyme, may render the intestine more susceptible to bacterial infection, allowing organisms to adhere and translocate across the mucosa. Such enhancement of infection may contribute to the pathogenesis of NEC.

Clostridial pathogenicity in experimental necrotising enterocolitis in gnotobiotic quails and protective role of bifidobacteria

The pathogenesis of neonatal necrotising enterocolitis (NEC) remains unclear. Gnotobiotic quails fed a lactose diet have been used to investigate the role of clostridial strains originating from faecal specimens of neonates through the intestinal lesions, the changes in microflora balance and the production of bacterial metabolites, i.e., short-chain fatty acids and hydrogen. Bifidobacteria are thought to exert various beneficial effects on host health, including interaction with the colonic microflora. Therefore, it was hypothesised that a protective role could be exercised through bifidobacterial colonisation. A Clostridium butyricum strain (CB 155-3) and a whole faecal flora including three clostridial species (C. butyricum, C. perfringens, C. difficile), each from premature infants suffering from NEC, caused caecal lesions in quails similar to those observed in man, i.e., thickening of the caecal wall with gas cysts, haemorrhagic ulceration and necrotic areas. Conversely, a whole faecal flora including bifidobacteria (identified as Bifidobacterium pseudo-catenulatum) and no clostridia, isolated from a healthy premature infant, was unable to produce NEC-like lesions. When the two clostridial groups were associated with a Bifidobacterium strain (B. infantis-longum, CUETM 89-215, isolated from a healthy infant), bifidobacterial colonisation suppressed all pathological lesions. This study is the first demonstration of a protective role for bifidobacteria against NEC via the inhibition of growth of C. butyricum or the disappearance of C. perfringens. C. difficile was not found to be responsible for the aetiology of the caecal lesions in quails. The main effect of bifidobacteria on lactose fermentation was either a dramatic decrease or a disappearance of butyric acid. The protective role was not associated with changes in H2 production. Therefore, a new step between colonic colonisation and its relevance to NEC is thought to involve the fermentation of unabsorbed lactose into butyric acid at the onset of the disease.