What next in necrotizing enterocolitis?

Necrotizing enterocolitis (NEC) is a devastating disease of premature infants, with a mortality rate of 10-50%. It is uncommon in term infants and in premature infants who have not yet been fed. Most commonly NEC develops suddenly in a preterm infant who was otherwise well, with initial symptoms of abdominal distention, bilious or bloody emesis or gastric aspirates, hematochezia, and pneumatosis intestinalis, and sometimes progresses quickly to include bowel perforation, acidosis, shock, and death. Trigger factors (i.e. perinatal hypoxia, mild infection or formula feeding) cause focal mild intestinal mucosal injury. In the presence of proliferation of commensal bacteria, local breakdown of mucosal barrier may cause entry of bacterial products (e.g. lipopolysaccharides, platelet-activating factor). Endothelial platelet-activating factor and/or tumor necrotizing factor and/or direct stimulating effects of polymorphonuclear leukocytes cause proinflammatory cascade and focal necrosis, which increase the entry of large amounts of bacterial toxins, and then severe NEC, sepsis, and shock develop. Therapies for the prevention of NEC that appear to have some benefit are breastfeeding and antenatal steroids, and probably probiotics. Enteral immunoglobulin, polyunsaturated fatty acids, and arginine or glutamine supplementation are therapies for the prevention of NEC that do not appear to be of benefit. Enteral erythropoietin and enteral granulocyte colony-stimulating factor are promising novel therapies. Treatment options are limited to gut rest, parenteral nutrition, broad-spectrum antibiotics, and surgical interventions for enteral perforation. Two commonly used methods for NEC with intestinal perforation are laparotomy or primary peritoneal drainage ("patch, drain and wait"); however, the preferred method is controversial.     

Is pneumoperitoneum an absolute indication for surgery in necrotizing enterocolitis?

Background  Necrotizing enterocolitis (NEC) is the most common gastrointestinal medical/surgical emergency in neonates. Non-operative support is needed in 70% of NEC cases, and surgical intervention in the rest 30%. Historically, pneumoperitoneum has been considered as an absolute indication for laparotomy. In the present study we emphasize that pneumoperitoneum is not an absolute indication for exploratory laparotomy in NEC cases. Methods  We prospectively studied 58 patients with severe NEC having pneumoperitoneum on abdominal X-ray in the last 5 years. At the time of admission, the patients were given intravenous fluid, total parental nutrition, blood transfusion and broad spectrum antibiotics followed by abdominal tapping (paracentesis). All the patients with pneumoperitoneum were closely monitored for 48 hours if abdominal tapping was repeated. When the disease seemed to worsen clinically, radiologically and laboratorially, the patient was subjected to exploratory laparotomy. Results  Of the 58 patients, 40 were treated conservatively whereas 18 underwent surgical intervention. The overall mortality in the present study was 12.1%, including 5% of the patients managed conservatively and 27% of the patients undergoing surgery. Conclusions  Pneumoperitoneum is not an absolute indication for surgery in cases of neonatal NEC. Most of the patients can be treated conservatively.     

Psychiatric treatment: A risk factor for obesity?

BACKGROUND:

People with psychiatric diagnoses have increased physical health difficulties.

OBJECTIVES:

To examine the physical growth parameters documented in children receiving psychiatric treatment.

METHODS:

A chart review was performed on consecutive paediatric consultations in 1997 and 1998 on 34 children six to 12 years of age admitted to an intermediate-stay psychiatric inpatient service. Growth parameters of each child were plotted on standard growth curves. The prevalence of obesity (body mass index at or above the 95th percentile), absolute weight at or above the 95th and 50th percentiles, underweight status, tall and short stature, macrocephaly and microcephaly were calculated. The prevalence of atypical findings was compared with the expected prevalence of typical growth parameters in the general population. Risk factors for atypical growth parameters were recorded. An association between weight and specific medication use was explored.

RESULTS:

It was found that 11.8% of the children were obese. It was also found that 23.5% of the children had weight at or above the 95th percentile, 79.3% had weight at or above the 50th percentile, 14.7% had macrocephaly and 79.4% had a head circumference above the 50th percentile; these results were statistically significant. The mean number of psychotropic medications prescribed was 6.4, although there was no significant association between higher weight and current medication type.

CONCLUSIONS:

Children receiving inpatient psychiatric treatment were more likely to have higher weight than typical children. Monitoring growth parameters is an important component of the paediatric care of children with psychiatric diagnoses. Guidelines are required for obesity prevention and intervention in the context of the risk factors experienced by this high risk population.     

Primary anastomosis or ostomy in necrotizing enterocolitis?

In neonates requiring operation for necrotizing enterocolitis (NEC), the complications due to enterostomy (ES) and the need for another operation to restore continuity have prompted several surgeons to employ primary anastomosis (PA) after resection as the operative strategy of choice. Our objective was to compare primary anastomosis to stoma formation in this population using systematic review and meta-analysis. Publications describing both interventions were identified by searching multiple databases. Appropriate studies that reported outcomes after PA and ES for NEC were included for analysis that was performed using the MedCalc3000 software. Results are reported as odds ratios (OR, 95% CI). No randomized trials were identified. Twelve studies were included for the final analysis. Neonates who underwent PA were associated with significantly less risk of mortality when compared to those who underwent ES (OR 0.34, 95% CI 0.17–0.68, p 0.002), possibly due to differences in severity of NEC. Although the types of complications in these groups were different, there was no significant difference in risk of complication (OR 0.86, 0.55–1.33, p 0.50). In neonates undergoing an operation for severe NEC, there is no significant difference in the risk of complications between primary anastomosis and enterostomy. A definitive suggestion cannot be made regarding the choice of one operative strategy over another.     

Is ABO mismatch another risk factor for allogeneic hematopoietic stem cell transplantation in pediatric thalassemic patients?

The ABO incompatibility between donor and recipient is not considered a barrier to successful allogeneic HSCT. Nevertheless, conflicting data still exist about the influence of ABO incompatibility on transplant outcome in pediatric patients with thalassemia. Fifty‐one children with beta‐thalassemia major who underwent allogeneic HSCT were enrolled this study. Twenty‐three of them (45%) received an ABO‐incompatible transplant [minor ABO mismatch: six (26%), major ABO mismatch: fourteen (61%), and bidirectional mismatch: three (13%)]. In this study, ABO incompatibility did not significantly impair GVHD, VOD, neutrophil and platelet engraftment, TRM, OS and TFS. Particularly in major and bidirectional ABO‐mismatched patients, a delayed erythroid recovery was recorded as compared to the group receiving an ABO‐compatible graft (median time, 31 and 38 days vs. 19.5 days; p: 0.02 and p: 0.03). Median time to red cell transfusion independence was significantly longer in major ABO‐incompatible patients (median time, 87 days vs. 32 days; p: 0.001). Therefore, whenever feasible, major ABO‐mismatched donors should be avoided in HSCT recipients, to prevent delayed erythroid recovery with prolonged RBC transfusion needs and impaired quality of life.     

What animal model should I use to study necrotizing enterocolitis?

Unfortunately, we are all too familiar with the statement: “Necrotizing enterocolitis remains the leading cause of gastrointestinal surgical emergency in preterm neonates”.It's been five decades since the first animal models of necrotizing enterocolitis (NEC) were described. There remains much investigative work to be done on identifying various aspects of NEC, ranging from the underlying mechanisms to treatment modalities. Experimental NEC is mainly focused on a rat, mouse, and piglet models. Our aim is to not only highlight the pros and cons of these three main models, but to also present some of the less-used animal models that have contributed to the body of knowledge about NEC.Choosing an appropriate model is essential to conducting effective research and answering the questions asked. As such, this paper reviews some of the variations that come with each model.     

Could clinical scores guide the surgical treatment of necrotizing enterocolitis?

Purpose  

Test the diagnostic reliability of the score for neonatal acute physiology-perinatal extension-II (SNAPPE-II) and the metabolic derangement acuity score (MDAS) as predictors of surgery in patients with necrotizing enterocolitis (NEC).     

Glucose–6–phosphate dehydrogenase deficiency in India

Glucose–6–phosphate dehydrogenase (G6PD) deficiency is the commonest red cell enzymopathy in humans and has an X-linked inheritance. It has been reported from India more than 30 years ago and the prevalence varies from 0–27% in different caste, ethnic and linguistic groups. The major clinical manifestations are drug induced hemolytic anemia, neonatal jaundice and chronic non–spherocytic hemolytic anemia. Individuals with G6PD deficiency have a selective advantage against falciparum malaria. Thirteen biochemically characterized variants have been reported from India. At the molecular level, G6PD Mediterranean is the most common deficient variant in the caste groups whereas, G6PD Orissa is more prevalent among the tribal of India. The third common variant seen in India is G6PD Kerala–Kalyan     

Does intestinal permeability lead to organ failure in experimental necrotizing enterocolitis?

Purpose

The rat gavage model is used to explore the pathogenesis and treatment of necrotizing enterocolitis (NEC). Although intestinal histological damage is seen in this model, intestinal perforation is rarely observed. Whether organ failure occurs in this model is largely unknown. We hypothesised that increased intestinal permeability leads to organ failure in experimental NEC.

Methods

NEC was induced in neonatal rats by gavage feeding of hypertonic formula plus exposure to hypoxia plus oral lipopolysaccharide (4 mg/kg per day daily). Breast-fed rats were used for comparison. At 92 h, lactulose (3 mg) and mannitol (2 mg) were administered orally in 0.1 ml water. Four hours later, rats were killed and blood samples collected. Lactulose and mannitol were measured by gas chromatography–mass spectrometry and lactulose/mannitol ratio calculated as index of intestinal permeability. Plasma cardiac troponin-I was measured by ELISA as a marker of cardiac damage and plasma creatinine measured spectrophotometrically as a marker of renal failure.

Results

Experimental NEC induced an increase in intestinal permeability (P = 0.0002). This was associated with cardiac damage (P < 0.0001), and renal failure (P = 0.004).

Conclusion

Intestinal permeability is increased in experimental NEC in association with increased cardiac damage. Rat mortality may be due to cardiac failure secondary to an inflammatory response caused by increased intestinal permeability.     

Gastric bypass: a risk factor for neural tube defects? Case report

Gastric bypass surgery has become a safe and acceptable surgical weight loss treatment for individuals who suffer from morbid obesity. Patients who undergo this procedure are subject to vitamin deficiencies due to an iatrogenic malabsorptive state. Folate, a vitamin known for its role in the prevention of neural tube defects (NTDs), can be part of the deficiency spectrum resulting from this procedure. The authors describe the case of a woman who was nonadherent to multivitamin treatment after undergoing gastric bypass surgery. Her lack of understanding and appreciation of the relationship between gastric bypass surgery, folate deficiency, and NTDs may have contributed to her noncompliance with daily multivitamin consumption. As a result, her potential problems with folate absorption could have contributed to her subsequently giving birth to a child with a myelomeningocele. Thus, patient awareness and counseling along with aggressive vitamin supplementation among this particular population may help prevent the occurrence of NTDs after gastric bypass surgery.     

Surgery for necrotising enterocolitis: primary anastomosis or enterostomy?

The ideal surgical management of neonates with necrotising enterocolitis (NEC) is still a matter of debate. The purpose of this study was to compare the results of bowel resection with primary anastomosis with the results of bowel resection with enterostomy. Sixty-three neonates with NEC had a bowel resection in the acute phase of the disease in the period between February 1990 and March 2001. Thirty-four of them (54%) underwent resection of the bowel with primary anastomosis (Group A), and 29 (46%) had resection with enterostomy (Group B). Group A had a lower gestational age and lower birth weight. Mortality, complication rate, and postoperative weight gain were not significantly different between the groups. However, Group B had a significantly longer primary hospital stay (80±49 days versus 58±31 days, P<0.04) and needed a 2nd hospital stay for restoring gastrointestinal continuity. For both reasons, it can be argued that primary anastomosis is superior to enterostomy after resection.     

Does abdominal sonography provide additional information over abdominal plain radiography for diagnosis of necrotizing enterocolitis in neonates?

Purpose  

To explore whether addition of abdominal sonography (AUS) to plain radiography is helpful in the management of premature newborns with necrotizing enterocolitis (NEC).