Neonatal Nutrition Lecture -What We Know Right Now

A recent terrific lecture at Northside Hospital’s neonatology conference by Reese Clark highlighted what we know about neonatal nutrition and what we should be striving to achieve.  This blog entry has abbreviated/summarized this presentation. Though not intentional, some important material is likely to have been omitted; in addition, transcription errors are possible as well.

Dr. Clark was willing to share slides from his talk and a related talk on necrotizing enterocolitis:

Here are a couple of key points from his talk regarding postnatal growth and feedings:

  • Every baby needs good nutrition.  While this is an obvious point, a lot of effort is focused on aspects of care needed in only a small number of neonates.
  • New target for weight gain in premature infants should be 20 gm/kg/day.  This growth is associated with better outcomes (Pediatrics 2006; 117: 1253 Ehrenkranz RA).  In this study, which controlled for a large number of variables, those in the top quartile of growth had much lower rates of cerebral palsy and neurologic impairments.  These improvements were also significant when comparing those in the top quartile to those in the 2nd and 3rd quartiles who were not sicker than those in the top quartile.
  • Most premature neonates are not achieving adequate growth with z-scores for weight and height lower at discharge from the NICU than their z-scores at birth. That is, despite advances in enteral and parenteral nutrition, premature neonates are falling behind while in the NICU. (Clark RH, et al. Pediatrics 2003; 111: 986)
  • Recognizing the supremacy of human milk has been the most important advance and has lead to much lower rates of necrotizing enterocolitis.  There is now a great case for exclusive human milk (J Pediatr 2013; 163: 1592-95; BMC Res Notes 2013; 6: 459)
  • With parenteral nutrition, higher amounts of amino acid have been associated with less issues with hyperglycemia. (Pediatrics 2007; 120: 12: 86-96; Pediatrics 2013; 163: 1278-82)
  • Insulin for hyperglycemia has been associated with poorer outcomes.
  • Does carnitine help with lipid metabolism? No one really knows –no randomized trials.
  • Continuous NG feeds are not associated with fewer signs/symptoms (e.g.. apnea, bradycardia, arching) than NG bolus feeds.
  • Acid suppression in neonates is not effective and potentially harmful
  • We need to use the best growth curves for premature infants: Fenton and Olsen growth charts

Since there are not going to be any trials randomizing neonates into groups assigned to poor growth, we will not know with certainty the impact of good nutrition on long-term outcomes.  Issues with reverse causation and selection bias make it difficult to know whether those with poor growth had other factors besides their nutritional plan which contributed to their outcomes.

Bottomline: We need to continue to optimize nutrition in premature infants; this includes using human milk and preventing necrotizing enterocolitis (which includes avoid acid blockers).  Our goal should be to have infants leave the NICU better nourished than when they arrived.

Disclaimer: These blog posts are for educational purposes only. Specific dosing of medications (along with potential adverse effects) should be confirmed by prescribing physician.  This content is not a substitute for medical advice, diagnosis or treatment provided by a qualified healthcare provider. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a condition.

 

Maternal Obesity and Neurodevelopmental Outcomes

If there were not enough reasons to be concerned about the prevalence of obesity already, here’s another: there is growing evidence that maternal obesity (i.e. obesity in the mother at the beginning or prior to pregnancy) is associated with an increased risk for a number of neurodevelopment outcomes (J Pediatr 2014; 165: 891-6).  According to this medical progress report, there are a number of limitations in interpreting the studies associating obesity with these outcomes.

  1. Unclear what is the best measure of obesity and the best timing of measuring obesity
  2. “It is unclear whether obesity per se is the entity that causes adverse outcomes, or whether  obesity is only a marker for other factors” (eg. diet and activity)

With these limitations in mind, the authors review a number of studies.  Key points:

  • Cerebral palsy: “a dose-response relationship was seen, with any diagnosis of maternal obesity carrying a relative risk (RR) of 1.30 (95% CI 1.09-1.55) for CP.  With any diagnosis of morbid obesity, the RR was 2.70 (CI 1.89-3.86)
  • Autism: the risk of developing ASD (OR 1.67; CI 1.10-2.56) and NDD [neurodevelopmental delay] (OR 2.08; CI 1.20-3.61)
  • Cognitive deficits: maternal BMI “was inversely associated wit age 5 years IQ”
  • Behavioral/psychiatric disorders: “children of women who were both overweight and gained excess weight during pregnancy had a 2-fold (OR 2.10; CI 1.19-3.72) increased risk of ADHD symptoms compared with offspring of normal-weight women.” Also, some studies have shown an increased risk for schizophrenia in children of mothers with BMI >30.

Bottomline: obesity is not good for individuals and is associated with increased neuodevelopmental risk in offspring as well.

 

Chronic Care Mode: GJ tube Data

A lot has changed in the field of pediatric gastroenterology since I completed my training 16 years ago.  One technology that is used frequently now is the gastrojejunal (GJ) tube for feeding neurologically-impaired children.  Previously, GJ tubes were used as a temporary solution.  Part of the rational for short-term usage was that these tubes were often difficult to maintain; they could easily become dislodged or clogged.

A recent study documents the more frequent usage of GJ tubes and their indefinite usage to treat complex feeding issues (JPGN 2013; 56: 523-27).

This retrospective chart review encompassed a 10 year period (1999-2009) at a single academic center.  In total 33 patients were treated with GJ tubes with 160 placements.  The mean age at initial placement was 6 years and the mean weight 19.4 kg. 76% of the patients had cerebral palsy/neurologic disorder, 21% had congenital heart disease, and 9% had chronic lung disease.

Common indications for replacement: dislodgment, obstruction, coiling into stomach, and broken tubing.

Three techniques were used:

  1. Fluoroscopy with guide wire and subsequent GJ
  2. Gastroduodenscopy via gastrostomy site to place guidewire for GJ placement
  3. Tube placement during esophagogastroduodenoscopy

Most procedures (85%) did not require sedation.

Outcomes:

  • 13 (39%) maintained on GJ throughout study period
  • 10 (30%) converted to gastric or oral feeds
  • 5 (15%) surgical intervention
  • 5 (15%) deceased
  • Duration of tube survival: mean 91 days for Mic-Key GJ (low profile) and 177 days for  coaxial PEG-PEJ (e.g. 16 French Corflo gastric tube with 6 French jejunal tube)

When reading the study, it is hard to ignore Figure 3 which shows more than 30 placements per year after 2007 whereas the number was about two per year before 2001. In the discussion, the authors do not focus on how this technology has been embraced so widely.  It is mostly a discussion on the indications, methods, and complications.  Indications included high aspiration risk, intractable vomiting, failed Nissen fundoplication, and gastroparesis.  “Our study showed that long-term jejunal feeding via GJ tubes is possible and safe.”

My preference is generally to avoid GJ feedings as a primary intervention for long-term feeding problems.  That is, when patients need gastrostomy tube feeds but are prone to vomiting, most often a fundoplication is worthwhile.  When a patient has had a fundoplication that is no longer effective, a GJ tube should be considered.

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