[Necrotising enterocolitis]

Necrotising enterocolitis (NEC) is a serious complication of prematurity and strikes prematurely in all weight groups. The incidence has been almost unchanged during the latest decades suggesting a limited success with current diagnostic and preventative strategies. Researchers have been looking for novel diagnostic tools to lower the incidence of NEC. Researchers have suggested splitting up NEC in smaller entities to target the preventive strategies, yet no revolutionary tool has been presented. This review is a short overview of the latest knowledge concerning diagnostic strategies.

Lactobacillus paracasei subsp. paracasei F19 in Bell's stage 2 of necrotizing enterocolitis

AIM

The aim of this trial is to evaluate the role Lactobacillus paracasei in Bell's stage 2 in order to prevent the clinical progression to stage 3.

METHODS

A prospective study was approved and started in December 2008. Patients were infants with birth weight 600 to 1500 g. One group received probiotic supplementation (L. paracasei susp.paracasei F-19) and the control group received only standard medical treatment. The primary outcome was the progression to stage 3 as defined by Bell's modified criteria. Inclusion and exclusion criteria were created and discussed with parents before treatment.

RESULTS

Thirty-two patients (stage 2 NEC) were considered eligible for the study. Group A: 18 patients and Group B: 14 patients. Three patients in group A and six patients in group B had a clinical history of Bell's stage 3 NEC (P<0.05); oral supplementation of L. paracasei reduced the clinical progression of NEC. It was considered that an improvement in intestinal motility might have contributed to this result.

CONCLUSION

The use of Lactobacillus paracasei subsp. paracasei F-19 is safe; the low progression rate to stage 3 NEC suggests that the use of this probiotic in stage 2 NEC could be a valuable therapeutic option.

A simple presurgical necrotizing enterocolitis-mortality scoring system

OBJECTIVE

To assess the relationship between early laboratory parameters, disease severity, type of management (surgical or conservative) and outcome in necrotizing enterocolitis (NEC).

STUDY DESIGN

Retrospective collection and analysis of data from infants treated in a single tertiary care center (1980 to 2002). Data were collected on disease severity (Bell stage), birth weight (BW), gestational age (GA) and pre-intervention laboratory parameters (leukocyte and platelet counts, hemoglobin, lactate, C-reactive protein).

RESULTS

Data from 128 infants were sufficient for analysis. Factors significantly associated with survival were Bell stage (P<0.05), lactate (P<0.05), BW and GA (P<0.01, P<0.001, respectively). From receiver operating characteristics curves, the highest predictive value resulted from a score with 0 to 8 points combining BW, Bell stage, lactate and platelet count (P<0.001). At a cutoff level of 4.5 sensitivity and specificity for predicting survival were 0.71 and 0.72, respectively.

CONCLUSION

Some single parameters were associated with poor outcome in NEC. Optimal risk stratification was achieved by combining several parameters in a score.

Does necrotising enterocolitis impact the neurodevelopmental and growth outcomes in preterm infants with birthweight < or =1250 g?

AIM

To compare the long-term growth and neurodevelopmental outcomes at 36 months adjusted age in preterm infants (birthweight (BW) < or = 1250 g) with necrotising enterocolitis (NEC) with BW-matched controls.

METHODS

This is a case control study performed at a regional tertiary care neonatal intensive care unit. Infants with stage II or III NEC admitted to a regional tertiary care neonatal unit between 1995 and 2000 were identified. Each infant with NEC was matched by BW (+/-100 g) to next two infants admitted in the unit without NEC. Growth and neurodevelopmental outcomes at 36 months are compared.

RESULTS

In total, 51 infants with NEC and 102 controls met study eligibility criteria and 146/153 (94.3%) were prospectively followed for 36 months. Infants with NEC had more culture-proven sepsis (35.3% vs. 10.8%, P < 0.001); patent ductus arteriosus requiring therapy (64.7% vs. 45%, P = 0.02), chronic lung disease (60.7% vs. 45%, P = 0.04) and longer hospital stay (84 days vs. 71 days, P < 0.0001). There were no significant differences in growth outcomes between the two groups at 36 months. Overall 24% of infants with NEC had one major neurodevelopmental disability compared with 10% among control infants. Infants who developed NEC had significantly higher cognitive delay (i.e. cognitive index <70) and visual impairment. A logistic regression model identified NEC as a predictor of cognitive delay.

CONCLUSION

Preterm infants who develop NEC are at a significantly higher risk for developing neurodevelopmental disability. We recommend close neurodevelopmental follow up for all < or =1250 g infants who develop stage II or III NEC.

Sonographic evaluation of neonates with early-stage necrotizing enterocolitis

BACKGROUND

Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency in neonatal intensive care units. Ultrasonographic findings in early-stage NEC have not been described.

OBJECTIVE

To assess the diagnostic value of ultrasonography for the diagnosis and monitoring of patients with NEC.

MATERIALS AND METHODS

We evaluated the sonographic findings of early stages of NEC in 40 neonates who were clinically diagnosed with NEC when they were 2-28 days old. Their average gestational age was 32 weeks, and their mean weight was 1,850 g. All of the patients showed signs of bowel distention on abdominal radiography, with no evidence of pneumatosis intestinalis. We performed bowel sonography in all patients (n = 40), as well as in ten healthy neonates who served as a control group. The studies were conducted with a 10-MHz linear transducer from February 2003 to January 2004. We evaluated the echogenicity of the bowel wall, involved region, ascites, and portal venous gas at both initial and follow-up examinations. We divided the patients into two groups according to the bowel wall echogenicity pattern, group I with echogenic dots in the bowel wall and group II with dense granular echogenicities in the bowel wall. In order to identify any correlations between the ultrasonography and clinical findings, we evaluated the duration of parenteral feeding (NPO) in each group and compared two groups by means of a statistical analysis (Mann-Whitney test).

RESULTS

All of the neonates in the control group (n = 10) presented normal bowel wall echogenicity; the patients with NEC presented echogenic dots in 16 patients (40%) and dense granular echogenicities in 24 patients (60%). Portal venous gas was absent in all patients. On the follow-up examinations, the echogenicity of the bowel wall and ascites decreased in 37 patients (93%). The duration of NPO was 11.1 +/- 6.6 days in group I and 16.5 +/- 7.2 days in group II (P < 0.05).

CONCLUSION

Echogenic dots or dense granular echogenicities in the bowel wall can be seen in patients with early-stage NEC. Bowel sonography can be helpful for the early diagnosis and monitoring of patients with NEC.

Oral probiotics prevent necrotizing enterocolitis in very low birth weight neonates

OBJECTIVE

To test the hypothesis that normalizing the intestinal flora by administration of prophylactic probiotics would provide a natural defense, thereby reducing both the incidence and severity of necrotizing enterocolitis (NEC) in preterm neonates.

STUDY DESIGN

Neonates < or =1500 g birth weight were randomized to either receive a daily feeding supplementation with a probiotic mixture (Bifidobacteria infantis, Streptococcus thermophilus, and Bifidobacteria bifidus; Solgar, Israel) of 10(9) colony forming units (CFU)/day or to not receive feed supplements. NEC was graded according to Bell's criteria.

RESULTS

For 72 study and 73 control infants, respectively, birth weight (1152 +/- 262 g vs 1111 +/- 278 g), gestational age (30 +/- 3 weeks vs 29 +/- 4 weeks), and time to reach full feeds (14.6 +/- 8.7 days vs 17.5 +/- 13.6 days) were not different. The incidence of NEC was reduced in the study group (4% vs 16.4%; P=.03). NEC was less severe in the probiotic-supplemented infants (Bell's criteria 2.3 +/- 0.5 vs 1.3 +/- 0.5; P=.005). Three of 15 babies who developed NEC died, and all NEC-related deaths occurred in control infants.

CONCLUSION

Probiotic supplementation reduced both the incidence and severity of NEC in our premature neonatal population.

Oral probiotics reduce the incidence and severity of necrotizing enterocolitis in very low birth weight infants

OBJECTIVE

We evaluated the efficacy of probiotics in reducing the incidence and severity of necrotizing enterocolitis (NEC) in very low birth weight (VLBW) infants.

PATIENTS AND METHODS

A prospective, masked, randomized control trial was conducted to evaluate the beneficial effects of probiotics in reducing the incidence and severity of NEC among VLBW (<1500 g) infants. VLBW infants who started to fed enterally and survived beyond the seventh day after birth were eligible for the trial. They were randomized into 2 groups after parental informed consents were obtained. The infants in the study group were fed with Infloran (Lactobacillus acidophilus and Bifidobacterium infantis) with breast milk twice daily until discharged. Infants in the control group were fed with breast milk alone. The clinicians caring for the infants were blinded to the group assignment. The primary outcome was death or NEC (>or= stage 2).

RESULTS

Three hundred sixty-seven infants were enrolled: 180 in the study group and 187 in the control group. The demographic and clinical variables were similar in both groups. The incidence of death or NEC (>or= stage 2) was significantly lower in the study group (9 of 180 vs 24 of 187). The incidence of NEC (>or= stage 2) was also significantly lower in the study when compared with the control group (2 of 180 vs 10 of 187). There were 6 cases of severe NEC (Bell stage 3) in the control group and none in the study group. None of the positive blood culture grew Lactobacillus or Bifidobacterium species.

CONCLUSION

Infloran as probiotics fed enterally with breast milk reduces the incidence and severity of NEC in VLBW infants.

[Diagnosis and characteristics of the clinical course of necrotizing enterocolitis in children]

Necrotizing enterocolitis (NEC) is a disease of unknown etiology affecting mainly premature newborns and occurring in about 1 to 7% of all admissions to neonatal intensive care units. Among the greatest problems is the early diagnosis and adequate and timely treatment, surgery included. In the last quarter of the century the survival rate of premature infants was gradually increasing in national regions and worldwide and accordingly there is an increasing number of babies with NEC. To date, to treat patients with the diagnosed enterocolitis is a complicated problem. The mortality rate among the children remains high. In the period from 1978 to 2000 432 patients with NEC were admitted to the St. Petersburg Center of Neonatal Surgery in the Children Hospital N 1,300 of them requiring surgical interventions. The author's personal experience with the diagnosis and treatment of the disease allowed three main forms of the clinical course of the disease to be established: superacute, acute and subacute.

Long-term follow-up of patients with necrotizing enterocolitis

BACKGROUND/PURPOSE

Despite the rise in the incidence of necrotizing enterocolitis (NEC), there is a paucity of data regarding long-term patient outcome. The authors examined functional outcome of infants with NEC (n = 103) treated at our institution between 1991 and 1995.

METHODS

The authors reviewed the medical records of infants who were treated both operatively and nonoperatively, n = 103. Variables examined included gestational age, birth weight, Bell stage (I through III), operations performed, and mortality rate. Telephone interviews assessed school enrollment, developmental delay, bowel function, and nutritional status.

RESULTS

Children treated operatively had a lower gestational age than those in the nonoperative group. Likewise, birth weight in the operative group was significantly lower. Sixty-three percent of patients had stage III, and the remainder had stage II disease. The telephone response rate was 61%. Mean age at follow-up was 7.5 +/- 2.5 years. All children ate by mouth. Nearly all children were toilet trained. All children were less than the 50th percentile for height and weight, and the majority (83%) were enrolled in school full time.

CONCLUSION

Infants with stage II and III NEC who are treated operatively or nonoperatively have a favorable long-term outcome.

The changing face of surgical indications for necrotizing enterocolitis

PURPOSE

The aim of this study was to compare the proportion of operations for acute necrotizing enterocolitis (NEC) and post NEC strictures.

METHODS

The authors reviewed 195 charts of children referred to our institution for NEC or post-NEC strictures between 1990 and 1999. Seventy-one children were classified as Bell stage I and were excluded. The remaining 124 patients were classified as either Bell stage II or III and formed the basis of our study. These patients were subdivided into 2 groups: (1) group I (n = 69) comprised patients treated from 1990 until 1994 and (2) group II (n = 55) from 1995 until 1999. Statistical analysis consisted of X(2) and Student's t tests. Significance occurred when P less-than-or-equal 0.05.

RESULTS

Both groups were similar with regard to sex, obstetrical history, indomethacin use, umbilical artery catheter use, and enteral feeding. The total operative rate for all patients with either acute NEC or post NEC strictures increased over time from 46% (32 of 69) in group I to 69% (38 of 55) in group II (P <.01). Specifically, post-NEC stricture was the initial operation in 16% (5 of 32) of group I patients versus 37% (14 of 38) of group II patients (P <.05). Subdividing each group by method of treatment of their NEC showed that medically treated patients had an increased incidence of stricture over time (group I, 15% v. group II, 48%; P <.01). Surgically treated children maintained a similar rate of stricture (group I, 36% v. group II, 33%). The mortality rate was comparable in both groups.

CONCLUSIONS

At our institution, the total operative rate for necrotizing enterocolitis has increased over the last 10 years. This is because of 2 factors: (1) an increase in the percentage of stage III patients and (2) an increase in referrals for post--necrotizing enterocolitis strictures. No specific criteria could be identified to predict which patients were at risk for post--necrotizing enterocolitis strictures after medical treatment.

[NEC--neonatal necrotising enterocolitis--methods of treatment and outcome: a comparative analysis of Scottish (Glasgow) and Polish (Western Pomerania) cases]

The aim of the work was to perform a comparative analysis of medical files of 125 neonates with necrotising enterocolitis treated between 1990 and 1995 in two regional centres: Glasgow (Scotland) and Western Pomerania (Poland), and to search for factors constituting an indication for surgery in NEC. The following data contained in the medical documentation of NEC cases have been analyzed: maternal risk factors, perinatal abnormalities, neonatal risk factors, procedures performed in the neonate, feeding practices, clinical and radiological signs, time of onset of the disease, clinical staging of NEC according to Bell (modified by Walsh and Kliegman), methods of treatment, postoperative course and outcome. The analysis was performed in the whole material and in the subgroup of newborns weighing < 1500 g (low/extremely low birth weight babies). Glasgow neonates with NEC had significantly lower birth weight, gestational age, platelet count, and sodium level when compared to Pomeranian newborns, while the latter had significantly lower leukocyte count and shorter time of onset of the disease. In the subgroup of newborns weighing less than 1500 g, Glasgow neonates had significantly lower birth weight, gestational age, platelet count, and sodium level when compared to Pomeranian newborns, while the latter had significantly lower 1 minute Apgar score, pH and base excess (BE) values. Glasgow clinical NEC stage was significantly more severe (IIB-IIIB) when compared to Pomeranian neonates. A higher proportion of full-term neonates in the present study--31.2%--was diagnosed with NEC than in the literature. Hyponatremia with severe acidosis and low platelet count (especially below 100 x 10(9)/L) may constitute an easily available laboratory finding serving as an indicator for surgical intervention in NEC. Statistical analysis revealed that the selection of treatment was influenced in the Glasgow group by birth weight and in the Pomeranian group by the clinical stage of NEC. Overall mortality was 32.8% in the whole group of 125 neonates, 34.4% in the Glasgow and 31.2% in the Pomeranian group. However, Glasgow neonates had significantly lower birth weight and gestational age and were more severely ill. The mortality in the subgroup of Scottish neonates with primary peritoneal drainage was 55.5%, the majority presenting with significantly lower birth weight and stage IIIB of necrotising enterocolitis. In conservatively treated neonates, mortality was 13% in the whole group, 9% in the Glasgow group and 15% in the Pomeranian group. Overall mortality in neonates treated surgically was 46.6%. In the Glasgow group it was 23% without and 42% with primary peritoneal drainage, respectively. Surgical mortality in the Pomeranian group was 42%. Overall mortality was 5.6% in full-term newborns, 3.2% in the Glasgow group and 7.8% in the Pomeranian group. Primary peritoneal drainage is a valuable, mildly invasive method of initial, and in some cases final, treatment in severely ill NEC babies, especially with low birth weight. This method was not used in the Pomeranian group.

Primary peritoneal drainage for increasing ventilatory requirements in critically ill neonates with necrotizing enterocolitis

BACKGROUND/PURPOSE

Primary peritoneal drainage (PPD) is an established therapy for premature neonates with necrotizing enterocolitis (NEC) and free intraperitoneal air. This study seeks to evaluate the efficacy of PPD in ill premature neonates with severe abdominal distension and increasing ventilatory requirements without free intraperitoneal air.

METHODS

Eleven neonates (gestational age, 27 +/- 0.59 weeks; age, 25 +/- 4.3 days; birth weight, 862 +/- 67 g) with NEC underwent bedside PPD under local anesthesia for rapid clinical deterioration characterized by severe abdominal distension and increasing ventilatory requirements. None showed radiographic evidence of free intraperitoneal air. Mean airway pressure (MAP) and oxygenation-index (OI) were analyzed 24 hours before, immediately before and 24 hours after surgery. The patients were followed up to discharge from hospital. Statistical analyses were performed using analysis of variance (ANOVA) for repeated measures.

RESULTS

Mean airway pressure (MAP) showed a significant difference (P <.05) increasing from 7.1 +/- 0.75 cm H2O 24 hours before surgery to 11 +/- 1.3 cm H2O immediately before surgery and decreasing to 9.9 +/- 1.1 cm H2O 24 hours after drainage. Likewise, OI measured at the same time intervals showed significant differences (P <.05) deteriorating from 5 +/- 1.2 to 26 +/- 6.9 then improving to 13 +/- 3.5. A significant quadratic effect (P <.03) was evident for MAP and OI (ie, values significantly rose then fell). There were six 30-day survivors (55%), and 3 survived to discharge (27%). Of the long-term survivors, 2 required operative fistula closure, and 1 needed no further surgery.

CONCLUSION

Bedside PPD for increasing ventilatory requirements and abdominal distension in critically ill neonates with nonperforated NEC is a simple technique that offers rapid stabilization, although ultimate mortality rate remains high.

The clinical significance of thrombocytopenia in neonates with necrotizing enterocolitis

PURPOSE

The aim of this study was to evaluate the clinical significance of low platelet count in the surgical management of neonates with necrotizing enterocolitis (NEC).

METHODS

The clinical course of 58 consecutive neonates with advanced NEC (Bell's stages II or III) treated in the authors' hospital between 1995 and 1998 was reviewed. NEC in neonates who required operation was classified as isolated, multifocal, or pan-intestinal. Severe thrombocytopenia was defined as platelet count less than 100 x 10(9)/L. Rapid fall in platelet count was defined as fall greater than 150 x 10(9)/L within 24 hours to a level less than 100 x 10(9)/L.

RESULTS

Median birth weight was 1,564 g (range, 550 to 4,270) and gestational age was 31 weeks (range 23 to 41). Twenty-two neonates (38%) were below 1,000 g. Age at the onset of the disease was 13 days (range, 1 to 62). NEC was treated medically in 7 neonates (12%). Indications for operation included pneumoperitoneum in 23 neonates (45%), clinical deterioration in 19 (37%), and intestinal obstruction in 9 (18%). The nadir platelet count (lowest level during the course of disease) was lower in patients with stage III disease than in patients with stage II disease (P <.05). The greater the extent of the disease, the lower the platelet count (P =.012). The nadir platelet count was lower in infants who died than in survivors (P <.05). None of the patients with platelet count greater than 100 x 10(9)/L died. In predicting intestinal gangrene, severe thrombocytopenia has a sensitivity of 69%, specificity of 60%, and positive predictive value of 89%; rapid fall in platelet count has a sensitivity of 32%, specificity of 89%, and positive predictive value of 92%.

CONCLUSIONS

(1) A platelet count less than 100 x 10(9)/L or a rapid fall in platelet count represent poor prognostic factors. (2) Monitoring the platelet count during the course of NEC is useful; however, it cannot be used in isolation to predict the extent of the disease or survival rate.

Platelet-activating factor in infants at risk for necrotizing enterocolitis

BACKGROUND

Platelet-activating factor (PAF) is a heterogeneous phospholipid that has been implicated as participating in a number of perinatal disease processes including necrotizing enterocolitis (NEC).

METHODS

Baseline blood levels of PAF and related lipids (PAF-LL) were measured for 164 infants at risk for NEC from 3 neonatal intensive care units. Serial levels were obtained from the 11 infants in whom NEC developed.

RESULTS

The mean peak PAF-LL in the infants without NEC was 2.03 +/- 1.96 ng/mL. Infants with stage II (n = 6) and III (n = 5) NEC had elevated peak PAF-LL values (mean peak value 13.6 +/- 6.9 ng/mL). No PAF-LL measurements obtained from infants during stage II or III NEC were <2.03 ng/mL. Three infants had PAF-LL elevations before the development of any clinical or radiographic evidence of NEC. PAF-LL level increased as the severity of NEC increased and decreased with its resolution. Setting a PAF-LL level of 10.2 ng/mL as a cutoff for NEC had a positive predictive value of 100%.

CONCLUSIONS

PAF-LL determinations can complement clinical and radiographic studies to diagnose and follow the progression of NEC. PAF-LL may have a role in the evolution of NEC.

Circulating pro- and counterinflammatory cytokine levels and severity in necrotizing enterocolitis

OBJECTIVES

To evaluate the relationship between the severity of necrotizing enterocolitis (NEC) and circulating concentrations of proinflammatory cytokines interleukin (IL)-1beta and IL-8 and counterinflammatory cytokines IL-1 receptor antagonist (IL-1ra) and IL-10. These cytokines have been associated with bowel injury or inflammation and may be released more slowly or later than previously examined cytokines. Also, to determine if any one of these cytokines will predict the eventual severity of NEC when measured at symptom onset.

METHOD

Serial blood samples at onset, 8, 24, 48, and 72 hours were obtained from newborn infants with predefined signs and symptoms of NEC. Normal levels were defined from weight-, gestation-, and age-matched controls. Concentrations of the four cytokines were determined by enzyme-linked immunosorbent assay and compared throughout the time period by stage of NEC, using sepsis as a co-factor. Mean concentrations of each cytokine at onset were compared with the controls. Threshold values were obtained with the best combination of high sensitivity and high specificity for defining stage 1 NEC or for diagnosing stage 3 NEC at onset.

RESULTS

There were 12 cases of stage 1, 18 cases of stage 2, and 6 cases of stage 3 NEC included in the study, as well as 20 control infants. Concentrations of IL-8 and IL-10 were significantly higher in infants with stage 3 NEC from onset through 24 hours compared with infants with less severe NEC. At onset, concentrations of all four cytokines were significantly higher in stage 3 NEC. To identify, at onset, the infants with a final diagnosis of stage 3 NEC, an IL-1ra concentration of >130 000 pg/mL had a sensitivity of 100% and a specificity of 92%. At 8 hours, an IL-10 concentration of >250 pg/mL had a sensitivity of 100% and a specificity of 90% in identifying stage 3 NEC in infants with symptoms suggestive of NEC at onset.

CONCLUSIONS

The severity of NEC and its systemic signs and symptoms are not due to a deficiency of counterregulatory cytokines. In fact, mean concentrations of IL-1ra in NEC are higher than what has been reported in other populations. The cytokines IL-8, IL-1ra, and IL-10 are released later or more slowly after a stimulus and may be more useful in identifying, within hours of symptom onset, which infant will develop significant NEC.

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.