Alexis K. Potemkin

Tracheal Collapsibility in Healthy Volunteers during Forced Expiration: Assessment with Multidetector CT

PURPOSE To assess forced expiratory tracheal collapsibility in healthy volunteers by using multidetector computed tomography and to compare the results with the current diagnostic criterion for tracheomalacia. MATERIALS AND METHODS An institutional review board approved this HIPAA-compliant study. After informed consent was obtained, 51 healthy volunteers (age range, 25-75 years) with normal spirometry results and no history of smoking or risk factors for tracheomalacia were prospectively studied. Volunteers were imaged with a 64-detector row scanner, with spirometric monitoring at total lung capacity and during forced exhalation, with 40 mAs, 120 kVp, and 0.625-mm detector collimation. Cross-sectional area and sagittal and coronal diameters of the trachea were measured 1 cm above the aortic arch and 1 cm above the carina. The percentage of expiratory collapse, the reduction in sagittal and coronal diameters, and the number of participants exceeding the current diagnostic criterion (>50% expiratory reduction in cross-sectional area) for tracheomalacia were calculated. RESULTS The final study population included 25 men and 26 women (mean age, 50 years). The mean percentage of expiratory reduction in tracheal lumen cross-sectional area was 54.34% +/- 18.6 (standard deviation) in the upper trachea and 56.14% +/- 19.3 in the lower trachea. Forty (78%) participants exceeded the current diagnostic criterion for tracheomalacia in the upper and/or lower trachea. Decreases in cross-sectional area of the upper and lower trachea correlated well with decreases in sagittal (r = 0.807 and 0.688, respectively) and coronal (r = 0.779 and 0.751, respectively) diameters (P < .001 for each correlation). CONCLUSION Healthy volunteers demonstrate a wide range of forced expiratory tracheal collapse, frequently exceeding the current diagnostic criterion for tracheomalacia.

A.S.P.E.N. Clinical Guidelines: Nutrition Support of Neonatal Patients at Risk for Necrotizing Enterocolitis

BACKGROUND Necrotizing enterocolitis (NEC) is one of the most devastating diseases in the neonatal population, with extremely low birth weight and extremely preterm infants at greatest risk. METHOD A systematic review of the best available evidence to answer a series of questions regarding nutrition support of neonates at risk of NEC was undertaken and evaluated using concepts adopted from the Grading of Recommendations, Assessment, Development and Evaluation working group. A consensus process was used to develop the clinical guideline recommendations prior to external and internal review and approval by the A.S.P.E.N. Board of Directors. RESULTS/ CONCLUSIONS: (1) When and how should feeds be started in infants at high risk for NEC? We suggest that minimal enteral nutrition be initiated within the first 2 days of life and advanced by 30 mL/kg/d in infants ≥ 1, 000 g. (Weak) (2) Does the provision of mothers milk reduce the risk of developing NEC? We suggest the exclusive use of mothers milk rather than bovine-based products or formula in infants at risk for NEC. (Weak) (3) Do probiotics reduce the risk of developing NEC? There are insufficient data to recommend the use of probiotics in infants at risk for NEC. (Further research needed.) (4) Do nutrients either prevent or predispose to the development of NEC? We do not recommend glutamine supplementation for infants at risk for NEC (Strong). There is insufficient evidence to recommend arginine and/or long chain polyunsaturated fatty acid supplementation for infants at risk for NEC. (Further research needed.) (5) When should feeds be reintroduced to infants with NEC? There are insufficient data to make a recommendation regarding time to reintroduce feedings to infants after NEC. (Further research needed.).

Provision of a soy-based intravenous lipid emulsion at 1 g/kg/d does not prevent cholestasis in neonates.

BACKGROUND One of the most common and severe complications of long-term parenteral nutrition (PN) is PN-associated cholestasis. The soybean oil-based lipid emulsion administered with PN has been associated with cholestasis, leading to an interest in lipid reduction strategies. The purpose of this study was to determine whether the provision of a soybean oil-based lipid emulsion at 1 g/kg/d compared with 2-3 g/kg/d is associated with a reduced incidence of cholestasis. METHODS Retrospective review of neonates admitted between 2007 and 2011 with a gastrointestinal condition necessitating ≥ 21 days of PN support. Neonates were divided into 2 groups based on the intravenous lipid emulsion dose: 1-g group (1 g/kg/d) and 2- to 3-g group (2-3 g/kg/d). The primary outcome measure was the incidence of cholestasis. RESULTS Sixty-one patients met inclusion criteria (n = 29, 1-g group; n = 32, 2- to 3-g group). The 2 groups did not differ in any baseline characteristics other than associated comorbidities that were more common in the 2- to 3-g group. The duration of PN, the number of operative procedures and bloodstream infections, and enteral nutrition (EN) were similar between groups. The incidence of cholestasis was not different between groups (51.7%, 1-g group; 43.8%, 2- to 3-g group; P = .61), and there was no difference between groups in the time to cholestasis (32.6 ± 24.1 days, 1-g group; 27.7 ± 10.6 days, 2- to 3-g group; P = .48). Overall, 44.8% of patients with cholestasis were transitioned to full EN, and 55.2% were transitioned to a fish oil-based lipid emulsion after which the direct bilirubin normalized in all patients. CONCLUSION Lipid reduction to 1 g/kg/d does not prevent or delay the onset of cholestasis in neonates.

Neonates With Short Bowel Syndrome: An Optimistic Future for Parenteral Nutrition Independence

IMPORTANCE The introduction of hepatoprotective strategies and multidisciplinary management has significantly improved the outcome of neonates with short bowel syndrome (SBS) who require parenteral nutrition (PN). OBJECTIVE To determine the probability of weaning from PN based on intestinal length in neonates with SBS amidst the new era of hepatoprotective strategies and multidisciplinary management. DESIGN, SETTING, AND PARTICIPANTS Retrospective medical record review at a single-center academic institution. Neonates with no more than 100 cm of small intestine at a corrected gestational age of no more than 30 days who were diagnosed with a surgical gastrointestinal disease and PN dependent for at least 2 weeks were included. Data were collected from January 1, 2004, through June 1, 2012. EXPOSURE Neonates with SBS requiring PN. MAIN OUTCOMES AND MEASURES The probability of wean from PN without reinitiation for at least 1 year, as determined by logistic regression. Predictors of wean were evaluated using exact conditional logistic regression. Predictors of time to wean were determined by Cox proportional hazards regression. RESULTS Sixty-three patients with a median (25th percentile, 75th percentile [interquartile range (IQR)]) gestational age of 31 (27, 35) weeks, birth weight of 1423 (895, 2445) g, small intestinal length of 41.0 (24.0, 65.0) cm, and predicted length of 29.0% (17.1%, 45.5%) underwent analysis. Fifty-one patients (81%) received a fish oil-based lipid emulsion (1 g/kg/d), 40 (63%) were weaned, 11 (17%) remained PN dependent, 4 (6%) underwent transplant, and 8 (13%) died while on PN. Excluding patients who underwent transplant or died, the median (IQR) small intestinal length was 55.0 (28.0, 75.0) cm in weaned and 26.0 (14.0, 41.0) cm in PN-dependent patients (P = .006), with 40 of 51 (78%) weaned by study end. The cumulative probability of wean for patients with at least 50 cm of small intestine was 88% after 12 and 96% after 24 months. Patients with less than 50 cm of small intestine had a cumulative probability of wean of 23% after 12, 38% after 24, and 71% after 57 months. Small intestinal length was found to be the primary predictor of wean. Notable predictors of time to wean included the amount of small intestine remaining (hazard ratio, 1.94 [95% CI, 1.45-2.58] per 20 cm of intestine; P < .001), entirety of care within our institution (3.27 [1.59-6.72]; P = .001), and intestinal lengthening procedure (0.19 [0.04-0.84]; P = .03). CONCLUSIONS AND RELEVANCE The majority of patients will wean from PN despite short intestinal length, likely as a result of new management strategies combined with a multidisciplinary team approach.

A.S.P.E.N. Clinical Guidelines Nutrition Support of Neonatal Patients at Risk for Metabolic Bone Disease

BACKGROUND Premature infants are at increased risk for metabolic bone disease, with resulting delayed bone growth, osteopenia, and rickets. METHOD A systematic review of the best available evidence to answer a series of questions regarding neonatal patients at risk of metabolic bone disease receiving parenteral or enteral nutrition was undertaken and evaluated using concepts adopted from the Grading of Recommendations, Assessment, Development and Evaluation working group. A consensus process was used to develop the clinical guideline recommendations prior to external and internal review and approval by the American Society for Parenteral and Enteral Nutrition Board of Directors. QUESTIONS (1) What maternal risk factors predispose the neonate to metabolic bone disease? (2) What is the optimal type of feeding to promote neonatal bone health? (3) When and how should vitamin D supplements be administered? (4) Does parenteral nutrition (PN) predispose a neonate to metabolic bone disease, and if so, are there PN formulation recommendations to minimize this risk?

The natural history of cirrhosis from parenteral nutrition-associated liver disease after resolution of cholestasis with parenteral fish oil therapy.

OBJECTIVE To determine the natural history of cirrhosis from parenteral nutrition-associated liver disease (PNALD) after resolution of cholestasis with fish oil (FO) therapy. BACKGROUND Historically, cirrhosis from PNALD resulted in end-stage liver disease, often requiring transplantation for survival. With FO therapy, most children now experience resolution of cholestasis and rarely progress to end-stage liver disease. However, outcomes for cirrhosis after resolution of cholestasis are unknown and patients continue to be considered for liver/multivisceral transplantation. METHODS Prospectively collected data were reviewed for children with cirrhosis because of PNALD who had resolution of cholestasis after treatment with FO from 2004 to 2012. Outcomes evaluated included need for liver/multivisceral transplantation, mortality, and the clinical progression of liver disease. RESULTS Fifty-one patients with cirrhosis from PNALD were identified, with 76% demonstrating resolution of cholestasis after FO therapy. The mean direct bilirubin decreased from 6.4 ± 4 mg/dL to 0.2 ± 0.1 mg/dL (P < 0.001) 12 months after resolution of cholestasis, with a mean time to resolution of 74 days. None of the patients required transplantation or died from end-stage liver disease. Pediatric End-Stage Liver Disease scores decreased from 16 ± 4.6 to -1.2 ± 4.6, 12 months after resolution of cholestasis (P < 0.001). In children who remained PN-dependent, the Pediatric End-Stage Liver Disease score remained normal throughout the follow-up period. CONCLUSIONS Cirrhosis from PNALD may be stable rather than progressive once cholestasis resolves with FO therapy. Furthermore, these patients may not require transplantation and show no clinical evidence of liver disease progression, even when persistently PN-dependent.

Long-Term Fish Oil Lipid Emulsion Use in Children With Intestinal Failure–Associated Liver Disease

Background: Fish oil lipid emulsion (FOLE) and multidisciplinary care for infants with intestinal failure (IF) have been associated with reduced morbidity and mortality due to IF-associated liver disease (IFALD). With increased survival, a greater proportion of infants with IF are now able to remain on parenteral nutrition (PN) in the long term. The purpose of this study was to examine outcomes in children with IFALD who have required long-term PN and FOLE therapy due to chronic IF. Materials and Methods: A review of prospectively collected data was performed for children with IFALD who required at least 3 years of PN and FOLE therapy due to chronic IF. Outcomes examined include the incidence of death, transplantation, and essential fatty acid deficiency (EFAD), as well as growth parameters and the biochemical markers of liver disease. Results: Of 215 patients with IFALD treated from 2004–2015, 30 required PN and FOLE therapy for at least 3 years (median, 4.6 years). To date, no patients have died, required transplantation, or developed EFAD. Biochemical markers of liver disease normalized within the first year of therapy with no recurrent elevations in the long term. Weight-for age and length-for-age z scores improved and PN dependence decreased in the first year of therapy, with a stable rate of growth in the long term. Conclusions: Children with IFALD who required long-term PN and FOLE for chronic IF had no mortality, need for transplantation, EFAD, or recurrence of liver disease in the long term, allowing for continued intestinal rehabilitation.

Preservation of Biochemical Liver Function With Low-Dose Soy-Based Lipids in Children with Intestinal Failure Associated Liver Disease

Objectives: Intestinal failure–associated liver disease (IFALD) contributes to significant morbidity in pediatric patients with intestinal failure (IF); however, the use of parenteral nutrition (PN) with a fish oil–based intravenous (IV) emulsion (FO) has been associated with biochemical reversal of cholestasis and improved outcomes. Unfortunately, FO increases the complexity of care: because it can be administered only under Food and Drug Administration compassionate use protocols requiring special monitoring, it is not available as a 3-in-1 solution and is more expensive than comparable soy-based IV lipid emulsion (SO). Because of these pragmatic constraints, a series of patient families were switched to low-dose (1 g kg−1 day−1) SO following biochemical resolution of cholestasis. The present study examines whether reversal of cholestasis and somatic growth are maintained following this transition. Methods: The present study is a chart review of all children with IFALD who switched from FO to SO following resolution of cholestasis. Variables are presented as medians (interquartile ranges). Comparisons were performed using the Wilcoxon signed-rank test. Results: Seven patients ages 25.9 (16.2–43.2) months were transitioned to SO following reversal of cholestasis using FO. At a median follow-up of 13.9 (4.3–50.1) months, there were no significant differences between pretransition and post-transition serum alanine and aspartate aminotransferases, direct bilirubin, and weight-for-age z scores. Because of recurrence of cholestasis, 1 patient was restarted on FO after 4 months on SO. Conclusions: Biochemical reversal of IFALD and growth were preserved after transition from FO to SO in 6 of 7 (86%) patients. Given the challenges associated with the use of FO, SO may be a viable alternative in select patients with home PN.

Cholestasis and growth in neonates with gastroschisis

PURPOSE The aim of this study was to determine the incidence of cholestasis and the correlation between cholestasis and weight-for-age z scores in parenteral nutrition-dependent neonates with gastroschisis. METHODS A single-center retrospective review of 59 infants born with gastroschisis from January 2000 to June 2007 was conducted. Demographic and clinical data were collected and analyzed. Subjects were divided into cholestatic and noncholestatic groups. Statistical analyses included the Student t test, Wilcoxon rank sum test, Fisher exact test, and a general linear model. RESULTS Fifty-nine neonates with gastroschisis were identified, and 16 (28%) of 58 patients developed cholestasis. Younger gestational age and cholestasis were found to be independently associated with weight-for-age z score in 30 of 58 patients with available long-term follow-up data. CONCLUSIONS Parenteral nutrition-dependent neonates with gastroschisis remain at considerable risk for the development of cholestasis. Both gestational age and cholestasis were found to be independent risk factors, predisposing these neonates to poor postnatal growth.

Challenging the 48-Hour Rule-Out for Central Line–Associated Bloodstream Infections in the Pediatric Intestinal Failure Population A Retrospective Pilot Study

INTRODUCTION While parenteral nutrition (PN) has revolutionized the management of patients with intestinal failure (IF), central line-associated bloodstream infections (CLABSIs) remain a leading cause of mortality and morbidity in this population. The objective of this study is to characterize the presentation of CLABSIs in pediatric IF and to determine the time to positivity of blood cultures. METHODS A retrospective cohort study of children with IF who presented to our institution for evaluation of a possible CLABSI from January 1, 2012, to December 31, 2012, was performed. RESULTS Sixty patients with IF were identified. There were 33 cases of CLABSI in 16 patients, with a rate of 1.5 infections per 1000 catheter days. There were no significant differences in age, growth parameters, or catheter days between patients with or without CLABSI. Fever was documented in 85% of patients with CLABSI. These patients demonstrated an increased percentage of neutrophils and higher C-reactive protein levels compared with patients without CLABSI. The mean time to culture positivity was 13.2 hours, and 97% of cultures were positive within 24 hours. CONCLUSION Our data suggest that most pediatric patients with IF who have CLABSI develop positive cultures within 24 hours, and the absence of fever and leukocytosis does not necessarily indicate the absence of infection. These findings may support clinical practice guidelines in favor of shorter hospital stay when CLABSI is suspected; however, a prospective analysis of CLABSI in this population is recommended to determine the safety and appropriate setting prior to any practice change.