Predictors of Mortality in Very Low Birth Weight Neonates With Congenital Diaphragmatic Hernia

BACKGROUND

Limited data exists regarding the mortality of very low birth weight (VLBW) neonates with congenital diaphragmatic hernia (CDH). This study aims to quantify and determine predictors of mortality in VLBW neonates with CDH.

METHODS

This analysis of 829 U.S. NICUs included VLBW [birth weight ≤1500g] neonates, born 2011-2021 with and without CDH. The primary outcome was in-hospital mortality. A generalized estimating equation regression model determined the adjusted risk ratio (ARR) of mortality.

RESULTS

Of 426,140 VLBW neonates, 535 had CDH. In neonates with CDH, 48.4% had an additional congenital anomaly vs 5.5% without. In-hospital mortality for neonates with CDH was 70.4% vs 12.6% without. Of those with CDH, 73.3% died by day of life 3. Of VLBW neonates with CDH, 38% were repaired. A subgroup analysis was performed on 60% of VLBW neonates who underwent delivery room intubation or mechanical ventilation, as an indicator of active treatment. Mortality in this group was 62.7% for neonates with CDH vs 16.4% without. Higher Apgars at 1 min and repair of CDH were associated with lower mortality (ARR 0.91; 95%CI 0.87,0.96 and ARR 0.28; 0.21,0.39). The presence of additional congenital anomalies was associated with higher mortality (ARR 1.14; 1.01,1.30).

CONCLUSION

These benchmark data reveal that VLBW neonates with CDH have an extremely high mortality. Almost half of the cohort have an additional congenital anomaly which significantly increases the risk of death. This study may be utilized by providers and families to better understand the guarded prognosis of VLBW neonates with CDH.

TYPE OF STUDY

Level II.

LEVEL OF EVIDENCE

Level II.

Comparing Healthcare Needs in Extremely Low Birth Weight Infants With NEC and Spontaneous Intestinal Perforation

BACKGROUND

Necrotizing enterocolitis (NEC) and spontaneous intestinal perforation (SIP) affect 6-8% of extremely low birth weight (ELBW) infants. SIP has lower mortality than NEC, but with similar short-term morbidity in length of stay, growth failure, and supplemental oxygen requirements. Comparative long-term neurodevelopmental outcomes have not been clarified.

METHODS

Data were prospectively collected from 59 North American neonatal units, regarding ELBW infants (401-1000 g or 22-27 weeks gestational age) born between 2011 and 2018 and evaluated again at 16-26 months corrected age. Outcomes were collected from infants with laparotomy-confirmed NEC, laparotomy-confirmed SIP, and those without NEC or SIP. The primary outcome was severe neurodevelopmental disability. Secondary outcomes were weight <10th percentile, medical readmission, post-discharge surgery and medical support at home. Adjusted risk ratios (ARR) were calculated.

RESULTS

Of 13,673 ELBW infants, 6391 (47%) were followed including 93 of 232 (40%) with NEC and 100 of 235 (42%) with SIP. There were no statistically significant differences in adjusted risk of any outcomes when directly comparing NEC to SIP (ARR 2.35; 95% CI 0.89, 6.26). However, infants with NEC had greater risk of severe neurodevelopmental disability (ARR 1.43; 1.09-1.86), rehospitalization (ARR 1.46; 1.17-1.82), and post-discharge surgery (ARR 1.82; 1.48-2.23) compared to infants without NEC or SIP. Infants with SIP only had greater risk of post-discharge surgery (ARR 1.64; 1.34-2.00) compared to infants without NEC or SIP.

CONCLUSIONS

ELBW infants with NEC had significantly increased risk of severe neurodevelopmental disability and post-discharge healthcare needs, consistent with prior literature. We now know infants with SIP also have increased healthcare needs.

LEVELS OF EVIDENCE

Level II.

Factors associated with D-lactic acidosis in pediatric intestinal failure: A case-control study

BACKGROUND

D-lactic acidosis (DLA) is a serious complication of short bowel syndrome (SBS) in children with intestinal failure (IF). Malabsorbed carbohydrates are metabolized by bacteria in the intestine to D-lactate which can lead to metabolic acidosis and neurologic symptoms.

METHODS

A retrospective chart review was performed in children ≤18 years old with SBS who had one of the following criteria: unexplained metabolic acidosis, neurologic signs or symptoms, history of antibiotic therapy for small bowel bacterial overgrowth, or high clinical suspicion of DLA. Cases had serum D-lactate concentration >0.25 mmol/L; controls with concentrations ≤0.25 mmol/L.

RESULTS

Of forty-six children, median age was 3.16 (interquartile range (IQR): 1.98, 5.82) years, and median residual bowel length was 40 (IQR: 25, 59) cm. There were 23 cases and 23 controls. Univariate analysis showed that cases had significantly lower median bicarbonate (19 vs. 24 mEq/L, p = 0.001), higher anion gap (17 vs. 14 mEq/L, p < 0.001) and were less likely to be receiving parenteral nutrition, compared with children without DLA. Multivariable analysis identified midgut volvulus, history of intestinal lengthening procedure, and anion gap as significant independent risk factors. Midgut volvulus was the strongest independent factor associated with DLA (adjusted odds ratio = 17.1, 95% CI: 2.21, 133, p = 0.007).

CONCLUSION

DLA is an important complication of pediatric IF due to SBS. Patients with IF, particularly those with history of midgut volvulus, having undergone intestinal lengthening, or with anion gap acidosis, should be closely monitored for DLA.

Association between neurodevelopmental outcomes and concomitant presence of NEC and IVH in extremely low birth weight infants

OBJECTIVE

To quantify the association between necrotizing enterocolitis (NEC) and neurodevelopmental disability (NDI) in extremely low birth weight (ELBW) infants with intraventricular hemorrhage (IVH).

STUDY DESIGN

ELBW survivors born 2011-2017 and evaluated at 16-26 months corrected age in the Vermont Oxford Network (VON) ELBW Follow-Up Project were included. Logistic regression determined the adjusted relative risk (aRR) of severe NDI in medical or surgical NEC compared to no NEC, stratified by severity of IVH.

RESULTS

Follow-up evaluation occurred in 5870 ELBW survivors. Compared to no NEC, medical NEC had no impact on NDI, regardless of IVH status. Surgical NEC increased risk of NDI in patients with no IVH (aRR 1.69; 95% CI 1.36-2.09), mild IVH (aRR 1.36;0.97-1.92), and severe IVH (aRR 1.35;1.13-1.60).

CONCLUSIONS

ELBW infants with surgical NEC carry increased risk of neurodevelopmental disability within each IVH severity stratum. These data describe the additive insult of surgical NEC and IVH on neurodevelopment, informing prognostic discussions and highlighting the need for preventative interventions.

Factors Associated With Chronic Intestinal Inflammation Resembling Inflammatory Bowel Disease in Pediatric Intestinal Failure: A Matched Case-Control Study

BACKGROUND AND AIMS

There is a subset of intestinal failure patients with associated chronic intestinal inflammation resembling inflammatory bowel disease. This study aimed to evaluate factors associated with chronic intestinal inflammation in pediatric intestinal failure.

METHODS

This was a single-center retrospective case-control study of children <18 years old with intestinal failure. Cases were defined by abnormal amounts of chronic intestinal inflammation on biopsies. Children with diversion colitis, eosinophilic colitis, or isolated anastomotic ulceration were excluded. Cases were matched 1:2 to intestinal failure controls based on sex, etiology of intestinal failure, and duration of intestinal failure. Multivariable conditional logistic regression was used to compare clinical factors between cases and controls, accounting for clustering within matched sets. A subgroup analysis was performed assessing factors associated with escalation of anti-inflammatory therapy.

RESULTS

Thirty cases were identified and matched to 60 controls. On univariate analysis, longer parenteral nutrition (PN) duration (1677 vs 834 days, P = 0.03), current PN use (33.3% vs 20.0%, P = 0.037), and culture-proven bacterial overgrowth (53.3% vs 31.7%, P = 0.05) were associated with chronic intestinal inflammation. On multivariable analysis, no variable reached statistical significance. On subgroup analysis, duration of intestinal failure, location of inflammation, and worst degree of inflammation on histology were associated with escalation of therapy.

CONCLUSIONS

PN dependence and intestinal dysbiosis are associated with chronic intestinal inflammation in children with intestinal failure. Severity of inflammation is associated with escalation of therapy. Further analysis is needed to assess these associations and the efficacy of treatments in this population.

High Rate of Venous Thromboembolism in Severe Pediatric Intestinal Failure

OBJECTIVE

To quantify the rate of venous thromboembolism (VTE) in patients with pediatric intestinal failure and identify associated risk factors.

STUDY DESIGN

We performed a retrospective cohort study in pediatric patients (<21 years old) with severe pediatric intestinal failure (≥90 consecutive days of parenteral nutrition) secondary to short bowel syndrome who were treated from 2014 to 2021 at an interdisciplinary intestinal rehabilitation program. The primary outcome was the incidence of VTE. Multivariable regression was performed to identify independent clinical predictors of VTE.

RESULTS

A total of 263 patients (59.7% male) met the criteria for inclusion. The cumulative incidence of VTE was 28.1%, with a rate of 0.32 VTEs per 1000 catheter-days. On univariate analysis, the number of catheter days, number of catheters, and history of central line-associated blood stream infection were associated with VTE. On multivariable logistic regression, a higher number of catheters was an independent risk factor for VTE (aOR, 1.17; 95% CI, 1.06-1.29). Additionally, earlier gestational age was a risk factor for VTE such that every week decrease in gestational age conferred a 9% increased risk of VTE (aOR, 1.09; 95% CI, 1.02-1.16).

CONCLUSIONS

In this retrospective study, 28.1% of patients with severe pediatric intestinal failure developed VTE; the number of catheters and early gestational age were noted to be independent risk factors for VTE. This high incidence of VTE highlights the need to investigate VTE in pediatric intestinal failure prospectively, including the potential benefit of prophylactic anticoagulation.

Current short bowel syndrome management: An era of improved outcomes and continued challenges

Prior to the late 1960s, pediatric short bowel syndrome was a frequently fatal disease. Currently, pediatric interdisciplinary bowel rehabilitation centers report very high survival rates. The mortality trends, up-to-date definitions, incidence, causes, and clinical manifestations of short bowel syndrome are reviewed. Emphasis is placed upon the nutritional, medical, and surgical advances that have contributed to the dramatic improvement in outcomes for pediatric short bowel syndrome patients. Recent findings and remaining challenges are highlighted.

Impact of concomitant necrotizing enterocolitis on mortality in very low birth weight infants with intraventricular hemorrhage

OBJECTIVE

To evaluate the impact of necrotizing enterocolitis (NEC) on mortality in very low birth weight (VLBW) infants with intraventricular hemorrhage (IVH).

STUDY DESIGN

Data were collected on VLBW infants born 2014-2018 at Vermont Oxford Network (VON) centers. NEC and IVH were categorized by severity. Adjusted risk ratios (ARR) for in-hospital mortality were calculated.

RESULTS

This study included 187 187 VLBW infants. Both medical and surgical NEC increased mortality risk compared to those without NEC. Stratification by IVH severity modified this effect (no IVH: ARR 3.04 (95%CI 2.74-3.38) for medical NEC and 4.17 (3.84-4.52) for surgical NEC; mild IVH: ARR 2.14 (1.88-2.44) for medical NEC and 2.49 (2.24-2.78) for surgical NEC; severe IVH: ARR 1.14 (1.03-1.26) for medical NEC and 1.10 (1.02-1.18) for surgical NEC).

CONCLUSION

The relative impact of NEC on mortality decreased as IVH severity increased. Given the frequent coexistence of NEC and IVH, these data inform multidisciplinary management of these complex patients.

Current outcomes of infants with esophageal atresia and tracheoesophageal fistula: A multicenter analysis

OBJECTIVE

This study aims to quantify mortality rates and hospital lengths of stay (LOS) in neonates with esophageal atresia and tracheoesophageal fistula (EA/TEF), and to characterize the effects of birth weight (BW) and associated congenital anomalies upon these.

METHODS

Data regarding patients with EA/TEF were prospectively collected (2013-2019) at 298 North American centers. The primary outcome was mortality and secondary outcome was LOS.  Risk factors affecting mortality and LOS were assessed.

RESULTS

EA/TEF was diagnosed in 3290 infants with a median BW of 2476 g (IQR 1897,2970). In-hospital mortality was 12.7%. Mortality was inversely correlated with BW. After adjustment, the risk of mortality decreased by approximately 11% with every 100 g increase in BW. A significant congenital anomaly other than EA/TEF was diagnosed in 37.9% of patients. Risk of mortality increased in patients with associated congenital anomalies, most notably in those with a severe cardiac anomaly. Lower BW was associated with an increased mean LOS among survivors. Similar to mortality risk, additional anomalies were associated with prolonged LOS.

CONCLUSIONS

This study demonstrates an in-hospital mortality of over 10%. Both increased mortality and prolonged LOS are highly associated with lower birth weight and the presence of concomitant congenital anomalies.

Morbidity associated with laparotomy-confirmed spontaneous intestinal perforation: A prospective multicenter analysis

BACKGROUND

Differences in morbidities between spontaneous intestinal perforation (SIP) and necrotizing enterocolitis (NEC) are unknown.

METHODS

Prospectively collected multicenter data regarding very low birth weight (VLBW) infants 2015-2019 were analyzed. Diagnosis of SIP or NEC was laparotomy-confirmed in all patients. Multivariable regression modeling was used to assess adjusted length of stay (LOS; primary outcome) and adjusted risk ratios (ARR) for weight <10th percentile at discharge, and supplemental oxygen requirement at discharge.

RESULTS

Of 201,300 VLBW infants at 790 hospitals, 1523 had SIP and 2601 had NEC. Adjusted LOS was similar for SIP and NEC (92 vs 88 days, p = 0.08561), but significantly higher than seen without SIP or NEC (68 days, p<0.0001). The risk of growth morbidity at discharge was similar between SIP and NEC (74.2% vs 75.3%; ARR:1.00;0.94,1.06), but higher than infants without SIP or NEC (47.7%; ARR:0.50;0.47,0.53). Infants with NEC were less likely to require supplemental oxygen at discharge than infants with SIP (24.4% vs 34.9%; ARR:0.80; 0.71,0.89).

CONCLUSIONS

Although mortality is known to be lower in VLBW infants with SIP than NEC, this study highlights the similarly high morbidity experienced by both groups of infants. These benchmark data can help align counseling of families with expected outcomes.

LEVEL OF EVIDENCE

Level II.

TYPE OF STUDY

Prognosis study (Cohort Study).

Long-term assessment of bilirubin and transaminase trends in pediatric intestinal failure patients during the era of hepatoprotective parenteral nutrition

PURPOSE

This study aimed to characterize the relationship between hepatoprotective parenteral nutrition (PN) dependence and long-term serum liver tests in children with intestinal failure (IF).

METHODS

A retrospective review was performed of children with severe IF (> 90 consecutive days of PN) who were followed from 2012 to 2019 at a multidisciplinary intestinal rehabilitation program. Patients were stratified into three groups based on level of PN dependence at most recent follow up: EN (achieved enteral autonomy), mixed (parenteral and enteral nutrition), and PN (> 75% of caloric intake from PN). PN at any point for this cohort was hepatoprotective, defined as soy-based lipids < 1.5 g/kg/day, combination (soy, medium chain fatty acid, olive and fish oil) lipid emulsion, or fish oil-based lipid emulsion. Kaplan-Meier analysis and a generalized estimating equation (GEE) model were utilized to estimate time to normalization and trends, respectively, of two serum markers of liver health: direct bilirubin (DB) and alanine aminotransferase (ALT).

RESULTS

The study included 123 patients (67 EN, 32 mixed, 24 PN). Median follow up time was 4 years. Based on the Kaplan Meier curve, 100% of EN and mixed group patients achieved normal DB levels by 3 years, while 32% of the PN group had elevated DB levels (Fig. 1). At 5 years, 16% of EN patients had elevated ALT levels compared to 73% of PN patients (p < 0.001, Fig. 2). The PN group's ALT levels were 1.76-fold above normal at 3 years (95%CI 1.48-2.03) and 1.65-fold above normal at 5 years (95%CI 1.33-1.97, Fig. 3).

CONCLUSIONS

While serum bilirubin levels tend to normalize, long-term PN dependence in the era of hepatoprotective PN is associated with a persistent transaminase elevation in an overwhelming majority of patients. These data support continued vigilant monitoring of liver health in children with intestinal failure.

LEVEL OF EVIDENCE

III.

Trends in incidence and outcomes of necrotizing enterocolitis over the last 12 years: A multicenter cohort analysis

OBJECTIVE

We sought to describe changes in the incidence and mortality of necrotizing enterocolitis (NEC) and associated surgical management strategies for very low birth weight (VLBW) infants.

METHODS

Data were prospectively collected on VLBW infants (≤1500 g or < 29 weeks) born 2006 to 2017 and admitted to 820 U.S. centers. NEC was defined by the presence of at least one clinical and one radiographic finding. Trends analyses were performed to assess changes in incidence and mortality over time.

RESULTS

Of 473,895 VLBW infants, 36,130 (7.6%) were diagnosed with NEC, of which 21,051 (58.3%) had medical NEC and 15,079 (41.7%) had surgical NEC. Medical NEC decreased from 5.3% to 3.0% (p < 0.0001). Surgical NEC decreased from 3.4% to 3.1% (p = 0.06). Medical NEC mortality decreased from 20.7% to 16.8% (p = 0.003), while surgical NEC mortality decreased from 36.6% to 31.6% (p < 0.0001). In the surgical cohort, the use of primary peritoneal drainage (PPD) versus initial laparotomy rose from 23.2% to 46.8%.

CONCLUSION

The incidence and mortality of both medical and surgical NEC have decreased over time. Changes in surgical management during this time period included the increased utilization of primary peritoneal drainage.

TYPE OF STUDY

Prognosis study.

LEVEL OF EVIDENCE

Level II.

Long-term outcomes of severe surgical necrotizing enterocolitis

PURPOSE

We sought to describe long-term outcomes of infants with severe surgical necrotizing enterocolitis (NEC).

METHODS

Data were collected on infants with surgical NEC (2009-2018). Severe surgical NEC was defined by extensive bowel loss with residual bowel length <30 cm, and "NEC totalis" was identified per operative report. Post-operative management and long-term outcomes were assessed, including enteral autonomy, severe neurodevelopmental disability, and educational attainment.

RESULTS

Of 268 infants with surgical NEC, 41 (15%) had severe surgical NEC, and 14/41 were identified as "NEC totalis". Zero severe NEC vs. 8 (57%) "NEC totalis" patients were placed on comfort measures following initial surgery (p < 0.001). Twenty-five patients (93%) with severe NEC survived vs 3/6 with "NEC totalis" (p < 0.001). The 28 survivors (68%) were followed for a median (IQR) duration of 8(4,10) years. Nine (32%) with severe NEC were weaned from parenteral nutrition. Eight (29%) had ≥1 marker for severe neurodevelopmental disability, and 11/16(69%) (7-16 years) were attending school at last follow-up.

CONCLUSION

Long-term survival is excellent following initial discharge, and achievement of enteral autonomy is feasible in patients with severe surgical NEC. The majority of patients who survive do not have severe neurodevelopmental disability and participate in school. Given current survivals and outcomes, focus on measured residual bowel length may be more appropriate than the subjective term "NEC-totalis."

TYPE OF STUDY

Prognosis Study.

LEVEL OF EVIDENCE

Level II.

Tracheostomy in Very Low Birth Weight Infants: A Prospective Multicenter Study

OBJECTIVES

In this study, we benchmark outcomes and identify factors associated with tracheostomy placement in infants of very low birth weight (VLBW).

METHODS

Data were prospectively collected on infants of VLBW (401-1500 g or gestational age of 22-29 weeks) born between 2006 and 2016 and admitted to 796 North American centers. Length of stay (LOS), mortality, associated surgical procedures, and comorbidities were assessed, and infants who received tracheostomy were compared with those who did not. Multivariable logistic regressions were performed to identify risk factors for tracheostomy placement and for mortality in those receiving tracheostomy.

RESULTS

Of 458 624 infants of VLBW studied, 3442 (0.75%) received tracheostomy. Infants with tracheostomy had a median (interquartile range) LOS of 226 (168-304) days and a mortality rate of 18.8%, compared with 58 (39-86) days and 8.3% for infants without tracheostomy. Independent risk factors associated with tracheostomy placement included male sex, birth weight <1001 g, African American non-Hispanic maternal race, chronic lung disease (CLD), intraventricular hemorrhage, patent ductus arteriosus ligation, and congenital neurologic, cardiac, and chromosomal anomalies. Among infants who received tracheostomy, male sex, birth weight <751 g, CLD, and congenital anomalies were independent predictors of mortality.

CONCLUSIONS

Infants of VLBW receiving tracheostomy had twice the risk of mortality and nearly 4 times the initial LOS of those without tracheostomy. CLD and congenital anomalies were the strongest predictors of tracheostomy placement and mortality. These benchmark data on tracheostomy in infants of VLBW should guide discussions with patient families and inform future studies and interventions.

Long-Term Outcomes and Disease Burden of Neonatal Onset Short Bowel Syndrome

PURPOSE

The study aims to describe long-term outcomes and disease burden of neonatal onset short bowel syndrome (SBS).

METHODS

Utilizing the WHO criteria for adolescence, patients 10-19 years of age with neonatal onset SBS requiring parenteral nutrition (PN) for >90 days and followed by our multidisciplinary intestinal rehabilitation center between 2009 and 2018 were included for analysis.

RESULTS

Seventy adolescents with SBS were studied. Median (IQR) age at last follow up in our center was 15 (11, 17) years. There was 0% mortality in the cohort, and 94% remained transplant free. Fifty-three patients (76%) achieved enteral autonomy. Three patients were weaned from PN without transplantation after six years of follow-up and another four after ten years of care at our multidisciplinary center. Disease burden remained higher in adolescents receiving PN, including inpatient hospitalizations (p < 0.01), procedures (p = 0.01), clinic visits (p < 0.01), and number of prescribed medications (p < 0.01).

CONCLUSION

Survival for adolescents with neonatal onset SBS is excellent. Of the cohort studied, there was no mortality, and more than 75% achieved enteral autonomy. Disease burden remains high for adolescents who remain dependent on PN. However, achievement of enteral autonomy is feasible with long-term multidisciplinary rehabilitation.

TYPE OF STUDY

Prognosis study.

LEVEL OF EVIDENCE

Level II.

Long-term outcomes of ultrashort bowel syndrome due to malrotation with midgut volvulus managed at an interdisciplinary pediatric intestinal rehabilitation center

PURPOSE

The purpose of this study was to describe long-term outcomes of pediatric-onset ultrashort bowel syndrome owing to midgut volvulus managed at an interdisciplinary intestinal rehabilitation center.

METHODS

Patients with a history of malrotation and pediatric-onset midgut volvulus causing extensive bowel loss (<20% residual small bowel length expected for postconception age) and treated between 2010 and 2017 were reviewed. Data are expressed as median (IQR).

RESULTS

Twenty-three patients had midgut volvulus at age 1 (0-21) day leading to 9 (8-12) percent predicted residual bowel length. Eight (35%) had gastroschisis. Follow-up was 8.5 (6.6-12.2) years from volvulus. Five (22%) patients underwent intestinal/multivisceral transplantation, and all achieved enteral autonomy. Eighteen (78%) patients remained transplant-free, 7 of whom achieved enteral autonomy after 718 (682-1030) days of parenteral nutrition. Transplant-free enteral autonomy was achieved by 0/6 patients with gastroschisis, compared to 7/12 without gastroschisis (p = 0.04). For the overall group, 18 (78%) patients had small bowel bacterial overgrowth, and 7 manifested symptomatic D-lactic acidosis. We observed 2 mortalities, one awaiting transplant and one 4 years following transplantation.

CONCLUSION

Midgut volvulus owing to malrotation with extensive bowel loss is associated with favorable long-term survival. Transplant-free enteral autonomy may be feasible, particularly in the absence of gastroschisis.

TYPE OF STUDY

Prognosis study.

LEVEL OF EVIDENCE

IIb, retrospective cohort study.

Growth morbidity in extremely low birth weight survivors of necrotizing enterocolitis at discharge and two-year follow-up

PURPOSE

The purpose of this study was to examine postnatal growth outcomes and predictors of growth failure at 18-24months corrected age among extremely low birth weight (ELBW) survivors of necrotizing enterocolitis (NEC) compared to survivors without NEC.

METHODS

Data were collected prospectively on ELBW (22-27weeks gestation or 401-1000g birth weight) infants born 2000-2013 at 46 centers participating in the Vermont Oxford Network follow-up project. Severe growth failure was defined as <3rd percentile weight-for-age.

RESULTS

There were 9171 evaluated infants without NEC, 416 with medical NEC, and 462 with surgical NEC. Rates of severe growth failure at discharge were higher among infants with medical NEC (56%) and surgical NEC (61%), compared to those without NEC (36%). At 18-24months follow-up, rates of severe growth failure decreased and were similar between without NEC (24%), medical NEC (24%), and surgical NEC (28%). On multivariable analysis, small for gestational age, chronic lung disease, severe intraventricular hemorrhage or cystic periventricular leukomalacia, severe growth failure at discharge, and postdischarge tube feeding predicted <3rd percentile weight-for-age at follow-up.

CONCLUSIONS

ELBW survivors of NEC have higher rates of severe growth failure at discharge. While NEC is not associated with severe growth failure at follow-up, one quarter of ELBW infants have severe growth failure at 18-24months.

TYPE OF STUDY

Prognosis study.

LEVEL OF EVIDENCE

II.

Whole Body Protein Turnover and Net Protein Balance After Pediatric Thoracic Surgery: A Noninvasive Single-Dose 15 N Glycine Stable Isotope Protocol With End-Product Enrichment

BACKGROUND

We used the 15 N glycine urinary end-product enrichment technique to quantify whole body protein turnover following thoracic surgery.

MATERIALS AND METHODS

A single dose of 15 N glycine (2 mg/kg) was administered orally on postoperative day 1 to children (1-18 years) following thoracic surgery. 15 N enrichment of ammonia and urea was measured in mixed urine after 12 and 24 hours, respectively, and protein synthesis, breakdown, and net balance determined. Nitrogen balance (dietary intake minus urinary excretion) was calculated. Urinary 3-methylhistidine:creatinine ratio was measured as a marker of skeletal muscle protein breakdown.

RESULTS

We enrolled 19 subjects-median (interquartile range): age, 13.8 years (12.2-15.1); weight, 49.2 kg (38.4-60.8)-who underwent thoracotomy (n = 12) or thoracoscopic (n = 7) surgery. Protein synthesis and breakdown by 15 N enrichment were 7.1 (5.5-9) and 7.1 (5.6-9) g·kg-1 ·d-1 with ammonia (12 hours) as the end product, and 5.8 (3.8-6.7) and 6.7 (4.5-7.6) with urea (24 hours), respectively. Net protein balance by the 15 N glycine and urinary urea nitrogen methods were -0.34 (-0.47, -0.3) and -0.48 (-0.65, -0.28) g·kg-1 ·d-1 , respectively (rs = 0.828, P < .001). Postoperative change in 3-methylhistidine:creatinine ratio did not correlate significantly with protein breakdown or balance.

CONCLUSION

The single-dose oral administration of 15 N glycine stable isotope with measurement of urinary end-product enrichment is a feasible and noninvasive method to investigate whole body protein turnover in children. After major surgery, children manifest increased protein turnover and net negative balance due to increased protein breakdown.