Predicting Mortality or Intestinal Failure in Infants with Surgical Necrotizing Enterocolitis

Development of a Prediction Model for Surgery or Early Mortality at the Time of Initial Assessment for Necrotizing Enterocolitis

OBJECTIVE

 No available scale, at the time of initial evaluation for necrotizing enterocolitis (NEC), accurately predicts, that is, with an area under the curve (AUC) ≥0.9, which preterm infants will undergo surgery for NEC stage III or die within a week.

STUDY DESIGN

 This is a retrospective cohort study (n = 261) of preterm infants with <33 weeks' gestation or <1,500 g birth weight with either suspected or with definite NEC born at Parkland Hospital between 2009 and 2021. A prediction model using the new HASOFA score (Hyperglycemia, Hyperkalemia, use of inotropes for Hypotension during the prior week, Acidemia, Neonatal Sequential Organ Failure Assessment [nSOFA] score) was compared with a similar model using the nSOFA score.

RESULTS

 Among 261 infants, 112 infants had NEC stage I, 68 with NEC stage II, and 81 with NEC stage III based on modified Bell's classification. The primary outcome, surgery for NEC stage III or death within a week, occurred in 81 infants (surgery in 66 infants and death in 38 infants). All infants with pneumoperitoneum or abdominal compartment syndrome either died or had surgery. The HASOFA and the nSOFA scores were evaluated in 254 and 253 infants, respectively, at the time of the initial workup for NEC. Both models were internally validated. The HASOFA model was a better predictor of surgery for NEC stage III or death within a week than the nSOFA model, with greater AUC 0.909 versus 0.825, respectively, p < 0.001. Combining HASOFA at initial assessment with concurrent or later presence of abdominal wall erythema or portal gas improved the prediction surgery for NEC stage III or death with AUC 0.942 or 0.956, respectively.

CONCLUSION

 Using this new internally validated prediction model, surgery for NEC stage III or death within a week can be accurately predicted at the time of initial assessment for NEC.

KEY POINTS

· No available scale, at initial evaluation, accurately predicts which preterm infants will undergo surgery for NEC stage III or die within a week.. · In this retrospective cohort study of 261 preterm infants with either suspected or definite NEC we developed a new prediction model (HASOFA score).. · The HASOFA-model had high discrimination (AUC: 0.909) and excellent calibration and was internally validated..

Preventing severe necrotizing enterocolitis: Propensity score analysis of interventions associated with surgical NEC or NEC-associated death

PURPOSE

To determine what modifiable interventions used in the neonatal intensive care unit (NICU) are associated with severe necrotizing enterocolitis (NEC) requiring surgical intervention.

METHODS

A retrospective review of patients treated for NEC at a tertiary hospital from 1991 to 2016 was performed. Patient characteristics were used to calculate propensity scores for likelihood of exposure to seven interventions: enteral feeds, use of glucocorticoids, nonsteroidal anti-inflammatory drugs (NSAIDs), antacids, antibiotics, or umbilical arterial (UAC) and venous catheters (UVC). Conditional logistic regression was used to compare the odds of having surgical NEC if exposed to each treatment.

RESULTS

We included 195 NEC patients: 69 severe NEC managed with surgery and 126 non-severe NEC managed medically. After propensity score matching based on birth characteristics, exposure to glucocorticoids (OR 5.21, 95%CI: 1.62, 16.70), NSAIDs (OR 4.87, 95%CI: 1.67, 14.17), UVC (OR 2.53 (95%CI: 1.19, 5.73), and UAC (OR 4.91, 95%CI: 2.12, 11.37) were associated with surgical NEC in separate conditional logistic regression analyses. Including these treatments in a second round of propensity matching and conditional logistic regression revealed that glucocorticoids (OR 2.99, 95%CI: 1.01, 8.88), NSAIDs (OR 3.97, 95%CI: 1.41, 11.19), UVC (OR 3.07, 95%CI: 1.46, 6.48), and UAC (OR 5.10, 95%CI: 2.10, 12.36) were still associated with surgical NEC.

CONCLUSION

After controlling for birth confounders and common NICU supportive interventions, use of glucocorticoids, NSAIDs and umbilical catheters independently increased the odds of developing severe NEC requiring surgical intervention.

LEVEL-OF-EVIDENCE RATING

Case-control, Level III evidence.

Clinical determinants of intestinal failure and death in preterm infants with surgical necrotizing enterocolitis

OBJECTIVE

We sought to investigate the clinical determinants of intestinal failure and death in preterm infants with surgical NEC.

METHODS

Retrospective comparison of clinical information between Group A = intestinal failure (Parenteral nutrition (PN) >90 days) and death and Group B = survivors and with PN dependence < 90 days in preterm infants with surgical NEC.

RESULTS

Group A (n = 99/143) had a lower mean gestational age (26.4 weeks [SD3.5] vs. 29.4 [SD 3.5]; p = 0.013), lower birth weight (873 gm [SD 427g] vs. 1425 gm [894g]; p = <0.001), later age of NEC onset (22 days [SD20] vs. 16 days [SD 17]; p = 0.128), received surgery later (276 hours [SD 544] vs. 117 hours [SD 267]; p = 0.032), had cholestasis, received dopamine (80.6% vs. 58.5%; p = 0.010) more frequently and had longer postoperative ileus time (19.8 days [SD 15.4] vs. 11.8 days [SD 6.5]; p = <0.001) and reached full feeds later (93 days [SD 45] vs. 44 [SD 22]; p = <0.001) than Group B.On multivariate logistic regression, higher birth weight was associated with lower risk (OR 0.35, 95% CI 0.15-0.82; p = 0.016) of TPN > 90 days or death. Longer length of bowel resected (OR 1.76, 95% CI 1.02-3.02; p = 0.039) and longer postoperative ileus (OR 2.87, 95% CI 1.26-6.53; p = 0.011) were also independently associated with TPN >90days or death adjusted for gestational age and antenatal steroid treatment.

CONCLUSION

In preterm infants with surgical NEC, clinical factors such as lower birth weight, longer bowel loss, and postoperative ileus days were significantly and independently associated with TPN >90 days or death.

Effect of an exclusive human milk diet on feeding tolerance in preterm infants

OBJECTIVE

To compare the time to full enteral feeds in preterm infants fed exclusive human milk (EHM) - mother's own milk (MOM) fortified with human milk-based fortifier (HMBF), to those who received partial human milk (PHM) - MOM fortified with bovine milk-based fortifier (BMBF), and exclusive formula.

STUDY DESIGN

A single-center retrospective study of infants with birth weight <1250 g from 2013 to 2018. Data on feeding, growth and other short-term neonatal morbidities were collected.

RESULTS

On regression analysis, time to full enteral feeds was significantly higher in PHM compared to EHM group (β-coefficient 4.14, 95% CI 0.00-8.29) and formula-fed group compared to EHM (β-coefficient 4.3, 95% CI 0.32-8.20). No significant differences in growth velocity, length of stay and other morbidities were found between the groups.

CONCLUSION

Infants in EHM had better feeding tolerance and reached their enteral feed goals sooner compared to PHM and formula-fed groups.

Characteristics and outcomes of a multi-institution cohort of infants with necrotizing enterocolitis totalis

OBJECTIVE

To characterize the presentation, management and outcomes of infants with necrotizing enterocolitis totalis (tNEC) vs surgical non-totalis NEC (sNEC).

STUDY DESIGN

This retrospective study identified infants undergoing surgery for NEC through The Children's Hospitals Neonatal Database. Demographic, surgical and mortality characteristics were compared.

RESULTS

Of 1059 infants, 161 (15.2%) had tNEC. Perinatal characteristics did not differ. tNEC infants were older and were less likely to have pneumoperitoneum at referral (5.6% vs 13.1%, p < 0.001) or intestinal perforation at surgery (38.5% vs 66.7%, p < 0.001). Infants with tNEC were more acidotic preoperatively (7.1, [IQR 7, 7.3] vs 7.3, [IQR 7.2, 7.4], p < 0.001). Mortality was 96.9% for tNEC and 26.5% for sNEC (p < 0.001). tNEC cases varied by center, accounting for 0-43% of all surgical NEC cases.

CONCLUSIONS

Mortality is high for tNEC infants, who present at older age, with greater illness severity but are less likely to have intestinal perforation than sNEC infants.

Efficacy of abdominal ultrasound inspection in the diagnosis and prognosis of neonatal necrotizing enterocolitis

OBJECTIVE

This study aimed to identify the most useful ultrasound (US) features associated with definite neonatal necrotizing enterocolitis (NEC) and their prognostic values, particularly the calculated markers combined with important features.

METHODS

A total of 213 suspected NEC cases were collected from the neonatal department of our hospital from January 2015 to August 2017. Each infant received both X-ray and US examinations.

RESULTS

No differences were found in sex composition and delivery modes between groups. NEC-positive neonates had poorer prognosis compared to negative ones. The NEC group showed a higher frequency of abnormal signals. US showed higher NEC-related frequencies in different parameters. A variable (named predictor in US [PUS]) with five features was constructed. For NEC diagnosis, this variable provided a much higher area under the curve Q2 (AUC) (0.965) than other parameters. In this model, PUS had a cutoff value of 0.376 with a 0.900 sensitivity and 0.922 specificity. In prognosis, the closest factors were selected to draw a receiver operating characteristic curve, as well as a novel calculated variable US prognostic (USPro) marker. USPro had a much higher AUC (0.86) than other single features and showed a cutoff value of 0.18145, with 0.75 sensitivity and 0.84 specificity. This variable had a weaker power in prognosis when compared with PUS in diagnosis.

CONCLUSIONS

The application of abdominal color Doppler US can provide high accuracy and sensitivity in NEC diagnosis and also contribute to its prognosis, without induction of radiation. Suspected neonates should be examined using this technique as early as possible.

Predictive factors for surgical treatment in preterm neonates with necrotizing enterocolitis: a multicenter case-control study

Necrotizing enterocolitis (NEC) is one of the most common and lethal gastrointestinal diseases in preterm infants. Early recognition of infants in need for surgical intervention might enable early intervention. In this multicenter case-control study, performed in nine neonatal intensive care units, preterm born infants (< 30 weeks of gestation) diagnosed with NEC (stage ≥ IIA) between October 2014 and August 2017 were divided into two groups: (1) medical (conservative treatment) and (2) surgical NEC (sNEC). Perinatal, clinical, and laboratory parameters were collected daily up to clinical onset of NEC. Univariate and multivariate logistic regression analyses were applied to identify potential predictors for sNEC. In total, 73 preterm infants with NEC (41 surgical and 32 medical NEC) were included. A low gestational age (p value, adjusted odds ratio [95%CI]; 0.001, 0.91 [0.86-0.96]), no maternal corticosteroid administration (0.025, 0.19 [0.04-0.82]), early onset of NEC (0.003, 0.85 [0.77-0.95]), low serum bicarbonate (0.009, 0.85 [0.76-0.96]), and a hemodynamically significant patent ductus arteriosus for which ibuprofen was administered (0.003, 7.60 [2.03-28.47]) were identified as independent risk factors for sNEC.Conclusions: Our findings may support the clinician to identify infants with increased risk for sNEC, which may facilitate early decisive management and consequently could result in improved prognosis. What is Known: • In 27-52% of the infants with NEC, a surgical intervention is indicated during its disease course. • Absolute indication for surgical intervention is bowel perforation, whereas fixed bowel loop or clinical deterioration highly suggestive of bowel perforation or necrosi, is a relative indication. What is New: • Lower gestational age, early clinical onset, and no maternal corticosteroids administration are predictors for surgical NEC. • Low serum bicarbonate in the 3 days prior clinical onset and patent ductus arteriosus for which ibuprofen was administered predict surgical NEC.

Time of Onset of Necrotizing Enterocolitis and Focal Perforation in Preterm Infants: Impact on Clinical, Surgical, and Histological Features

Objective: There is no gold standard test for diagnosis of necrotizing enterocolitis (NEC). Timing of onset is used in some definitions and studies in an attempt to separate NEC from focal intestinal perforation (FIP) with 14 days used as a cutoff. In a large, detailed data set we aimed to compare NEC and FIP in preterm infants born <32 weeks gestation, presenting before 14 days of life in comparison to cases presenting later. Design: Infants with NEC or FIP when parents had consented to enrollment in an observational and sample collection study were included from 2009 to 2019. Clinical, surgical, histological, and outcome data were extracted and reviewed by each author independently. Patients/Episodes: In 785 infants, 174 episodes of NEC or FIP were identified of which 73 (42%) occurred before 14 days, including 54 laparotomies and 19 episodes of medically managed NEC ("early"). There were 56 laparotomies and 45 episodes of medically managed NEC presenting on or after 14 days age ("late"). Results: In early cases, 41% of laparotomies were for NEC (22 cases) and 59% for FIP (32 cases), and in late cases, 91% of laparotomies (51 cases) were for NEC and 9% (five cases) were for FIP. NEC presenting early was more likely to present with an initial septic presentation rather than discrete abdominal pathology and less likely to have clear pneumatosis. Early cases did not otherwise differ clinically, surgically, or histologically or in outcomes compared with later cases. FIP features did not differ by age at presentation. Conclusions: Although most FIP occurred early, 14% occurred later, whereas almost one third (29%) of NEC cases (surgical and medical) presented early. Infant demographics and surgical and histological findings of early- and late-presenting disease did not differ, suggesting that early and late cases are not necessarily different subtypes of the same disease although a common pathway of different pathogenesis cannot be excluded. Timing of onset does not accurately distinguish NEC from FIP, and caution should be exercised in including timing of onset in diagnostic criteria.

Clinical determinants of postoperative outcomes in surgical necrotizing enterocolitis

OBJECTIVE

Investigate predictors of postoperative morbidity and mortality in surgical NEC.

STUDY DESIGN

We analyzed the clinical outcomes of infants with surgical NEC from the years 2000-2015.

RESULTS

Ninety infants born at gestation (mean ± standard deviation, SD; standard error of mean, SEM) 27.3 ± 6.6 weeks (SEM ± 0.07 weeks) and weighing 1008 ± 456 g (SEM ± 48 g) developed NEC on 25.2 ± 22.4 days (SEM ± 2.4 days). Average bowel resection was 29.2 ± 30.5 cm (SEM ± 3.2 cm). Postoperative Ileus lasted 16.5 ± 12.2 days (SEM ± 1.3 days), and was significantly longer in infants with higher gestation and birth weight, age at onset of NEC, length of intestinal resection, maternal chorioamnionitis, and need for pressors. Thirty-eight (42.2%) infants died. Mortality was higher at gestation <31 weeks.

CONCLUSION

Gestational age, birth weight, age at NEC onset, and length of resected bowel determined postoperative morbidity and mortality in NEC. Length of hospital stay was affected by above factors, and also the duration of postoperative ileus and parenteral nutrition.

Contemporary Outcomes for Infants with Necrotizing Enterocolitis-A Systematic Review

OBJECTIVE

To develop an accurate understanding of outcomes for necrotizing enterocolitis (NEC) to inform parental counseling, clinical care, and research agendas.

STUDY DESIGN

A systematic review of recent (January 2010-January 2018) large cohort studies reporting outcomes of infants who developed NEC. Only studies reporting national, regional, or multicenter outcomes of NEC in high income countries were included. Outcomes assessed were mortality, neurodevelopmental outcome, and intestinal failure. Meta-analyses were used to generate summary statistics for these outcomes.

RESULTS

Of 1375 abstracts, 38 articles were included. Overall mortality was 23.5% in all neonates with confirmed NEC (Bell stage 2a+) (95% CI 18.5%-28.8%), 34.5% (30.1%-39.2%) for neonates that underwent surgery for NEC, 40.5% (37.2%-43.8%) for extremely low birthweight infants (<1000 g), and 50.9% (38.1%-63.5%) for extremely low birthweight infants with surgical NEC. Studies examining causes of neonatal mortality showed NEC is responsible for around 1 in 10 of all neonatal deaths. Neurodevelopmental disability was reported in 4 studies at between 24.8% and 61.1% (1209 total NEC cases). Three studies reported intestinal failure with an incidence of 15.2%-35.0% (n = 1370). The main limitation of this review is the lack of an agreed definition for diagnosing NEC and the differences in the way that outcomes are reported.

CONCLUSIONS

Mortality following NEC remains high. These contemporary data inform clinical care and justify ongoing research efforts. All infants with NEC should have long-term neurodevelopmental assessment. Data on the long-term risk of intestinal failure are limited.

TRIAL REGISTRATION

CRD42018094791.

Intestinal Oxygenation and Survival After Surgery for Necrotizing Enterocolitis: An Observational Cohort Study

OBJECTIVE

To assess whether regional intestinal oxygen saturation (rintSO2) and regional cerebral oxygen saturation (rcSO2) measurements aid in estimating survival of preterm infants after surgery for NEC.

SUMMARY OF BACKGROUND DATA

Predicting survival after surgery for NEC is difficult yet of the utmost importance for counseling parents.

METHODS

We retrospectively studied prospectively collected data of preterm infants with surgical NEC who had available rintSO2 and rcSO2 values measured via near-infrared spectroscopy 0-24 hours preoperatively. We calculated mean rintSO2 and rcSO2 for 60-120 minutes for each infant. We analyzed whether preoperative rintSO2 and rcSO2 differed between survivors and non-survivors, determined cut-off points, and assessed the added value to clinical variables.

RESULTS

We included 22 infants, median gestational age 26.9 weeks [interquartile range (IQR): 26.3-28.4], median birth weight 1088 g [IQR: 730-1178]. Eleven infants died postoperatively. Preoperative rintSO2, but not rcSO2, was higher in survivors than in non-survivors [median: 63% (IQR: 42-68) vs 29% (IQR: 21-43), P < 0.01), with odds ratio for survival 4.1 (95% confidence interval, 1.2-13.9, P = 0.02) per 10% higher rintSO2. All infants with rintSO2 values of >53% survived, whereas all infants with rintSO2 <35% died. Median C-reactive protein [138 mg/L (IQR: 83-179) vs 73 mg/L (IQR: 12-98), P < 0.01), lactate [1.1 mmol/L (IQR: 1.0-1.6) vs 4.6 mmol/L (IQR: 2.8-8.0), P < 0.01], and fraction of inspired oxygen [25% (IQR: 21-31) vs 42% (IQR: 30-80), P < 0.01] differed between survivors and non-survivors. Only rintSO2 remained significant in the multiple regression model.

CONCLUSIONS

Measuring rintSO2, but not rcSO2, seems of added value to clinical variables in estimating survival of preterm infants after surgery for NEC. This may help clinicians in deciding whether surgery is feasible and to better counsel parents about their infants' chances of survival.

A Quality Improvement Initiative to Increase Mother's Own Milk Use in a Chinese Neonatal Intensive Care Unit

Background: To evaluate the efficacy of a multidisciplinary quality improvement intervention to promote mother's own milk feeding and reduce necrotizing enterocolitis (NEC) in very low-birth-weight infants. Materials and Methods: We conducted a pre (January 2014 to March 2015)-post (April 2015 to June 2016), nonrandomized, interventional cohort study of infants born at <1,500 g birth weight and admitted to the Fudan University Children's Hospital level III neonatal intensive care unit in Shanghai. The intervention included establishing a breast milk promotion team and breast milk pumping room, educating staff and parents, and distributing teaching materials. The primary outcome was breast milk feeding rate. Secondary outcomes included incidences of NEC, NEC needing surgery, mortality, and time to full enteral feeds. Results: A total of 488 infants (210 baseline, 278 intervention) <1,500 g were enrolled. The intervention group had significantly increased feeding rates for any mother's milk (34.76% vs. 80.58%; p < 0.01) and high-volume mother's milk (≥50% of feeds; 22.86% vs. 61.15%; p < 0.01), and decreased incidence of NEC needing surgery (7.62% vs. 3.24%; adjusted odds ratio [OR] 0.32, 95% confidence interval [CI] 0.14-0.76). There were no significant differences in rates of mortality (0.5% vs. 1.49%; adjusted OR 2.10, 95% CI 0.22-19.6), NEC (10.00% vs. 7.55%; adjusted OR 0.59, 95% CI 0.31-1.14), and time to full enteral feeds (20.18 ± 1.67 days vs. 24.15 ± 1.65 days; adjusted OR = 1.09, 95% CI 0.99-1.21). Conclusions: Our quality improvement initiative increased the consumption of mother's own milk and reduced the severity of NEC in very low-birth-weight infants.

Toll-Like Receptor-Mediated Intestinal Inflammatory Imbalance in the Pathogenesis of Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) remains the leading cause of death from gastrointestinal disease in premature infants and attacks the most fragile patients at a time when they appear to be the most stable. Despite significant advances in our overall care of the premature infant, NEC mortality remains stubbornly high. There is no specific treatment for NEC beyond broad-spectrum antibiotics and intestinal resection, and current efforts have focused on preventive strategies. Over the past decade, we have proposed a unifying hypothesis to explain the pathogenesis of NEC in premature infants that suggests that NEC develops in response to an imbalance between exaggerated proinflammatory signaling in the mucosa of the premature gut leading to mucosal injury, which is not countered effectively by endogenous repair processes, and in the setting of impaired mesenteric perfusion leads to intestinal ischemia and disease development. One of the most important pathways that mediates the balance between injury and repair in the premature intestine, and that plays a key role in NEC pathogenesis, is Toll-like receptor 4 (TLR4), which recognizes lipopolysaccharide on gram-negative bacteria. This review focuses on the role that the TLR4-mediated imbalance between proinflammatory and anti-inflammatory signaling in the premature intestinal epithelium leads to the development of NEC, and will explore how an understanding of the role of TLR4 in NEC pathogenesis has led to the identification of novel preventive or treatment approaches for this devastating disease.