Nutrition Imbalance for Ventilated Children

A recent study documents a high rate of nutritional problems among a prospective cohort of 20 children on home ventilators and documents a metabolic assessment aimed at improving these problems (Martinez EE, et al. J Pediatr 2015; 166: 350-7, ed 228-29).

In these children the authors did careful nutritional assessment with anthropometry, bioelectrical impedance analysis (BIA), actual energy intake (AEI), and indirect calorimetry in the subject’s home. Indirect calorimetry was used to calculate a measured energy expenditure (MEE).

Indirect calorimetry allows measurement of energy expenditure: (From NASPGHAN Foundation N2U Course 2012, Praveen Goday: “Energy and Protein Metabolism”)

  • “When carbohydrate, protein, and fat are oxidized, oxygen is consumed and carbon dioxide is produced.”
  • “If oxygen consumption and carbon dioxide production can be measured, the energy released in the course of the utilization of these gases (or the energy expenditure can be determined.”
  • “The techniques is referred to as indirect, because gas exchange does not actually measure heat production.”

Key findings:

  • 13 were either underfed (AEI:MEE <90%) or overfed (AEI:MEE >110%)
  • 11 of 19 had suboptimal protein intake
  • 15 subjects were hypo or hypermetabolic

The authors conclude that a “majority of children on home ventilation are characterized by malnutrition, altered metabolic status, and suboptimal macronutrient intake” (especially low protein intake).  The discussion lists many of the study limitations: small number, discrepancies between some of their measuring tools, lack of long-term followup, lack of widespread availability of mobile indirect calorimetry, diverse comorbidities, and reliance of 3-day food records. In addition, the indirect calorimetry must be properly calibrated, performed when patient at baseline state, and feedings held (if on bolus feeds).

Although I think this study makes some important points, I think the ‘high-tech’ approach is overemphasized.  It would be interesting to see how (if at all) these interventions would improve a child who is followed closely by a nutritionist and a GI physician.  While precise measurement of resting energy expenditure, when performed properly, is informative, I think this information is much less helpful than serial basic measurements.

At the same time, there are many limitations on optimal nutrition in these children.  The mobility problems of many kids on home ventilators can make gaining weight problematic for care providers.  It is not practical for all caregivers to manage a 60 kg adolescent.

Recent advice from N2U () regarding children who were tube-fed/wheelchair-bound:

  • In children older than 10 years, if they are receiving 6 cans/day of commercial formula product, they are likely receiving adequate nutrients.
  • In children younger than 10 years, if if they are receiving 4 cans/day of commercial formula product, they are likely receiving adequate nutrients.
  • The newer reduced calorie formulas make it easier to provide adequate nutrients without excessive calories
  • Avoid obesity in these children.  Losing weight can be very difficult in this population.

Bottomline: Children on ventilators often are too heavy or too thin and need to be followed closely.  Whether indirect calorimetry is useful in this regard is not clear to me.

Briefly noted: A high nutrient diet appears to help treat fatigue (Nutrients 20157(3), 1965-1977).  From abstract (thanks to Kipp Ellsworth): A group of 98 children (2–18 years old) with unexplained symptoms of fatigue was examined. Children in the intervention group were asked to follow the diet for three months, whereas the control-group followed their normal diet.  The dietary modifications consisted of green vegetables, beef, whole milk and full-fat butter.

From NPR: Empathy Cards “Please Let Me Be the First to Punch the Next Person Who Says Everything Happens for a Reason”

Sarcopenia, fatigue, and nutrition in chronic liver disease

Several articles from a recent Clinical Gastroenterology and Hepatology have addressed nutritional aspects of chronic liver disease.

1. Sarcopenia?  This term refers to generalized loss of skeletal muscle.  It does not equate to malnutrition though there is significant overlap.  (Clinical Gastroenterology and Hepatology 2012; 10: 166-73 & editorial 100).  In this study, 112 adults with cirrhosis had CT scans which examined skeletal muscle at the L3 level; 40% had sarcopenia. Sarcopenia was independently associated with mortality and was not reflected in MELD score.  Patients had increased risk of death from sepsis and liver failure (HR 2.18).  Thus, sarcopenia joins hyponatremia, refractory ascites, hepatic encephalopathy as additional factors which add prognostic information to MELD score.

2. Fatigue in cirrhosis. (Clinical Gastroenterology and Hepatology 2012; 10: 174-81 & editorial 103).  Fatigue is common in cirrhosis and is multifactorial.  In this prospective study, 108 patients were evaluated with a fatigue impact scale. Fatigue improved after liver transplantation. Fatigue can be peripheral due to muscle weakness and dysfunction. And, fatigue can be central due to difficulty performing physical and mental activities.  Central fatigue is associated with an increased perceived effort for tasks and often related to depression; this type of fatigue is much more common with cirrhosis.  Although improved, fatigue often does not completely resolve with liver transplantation.

3. Nutrition recommendations. (Clinical Gastroenterology and Hepatology 2012; 10: 117-25).  A summary of nutrition recommendations in adults  with chronic liver disease is given in this article.  One common misconception is protein restriction.  This is not beneficial.  Protein recommendations are for adult patients with cirrhosis to receive 1-1.5 g/kg/day.  This amount is higher than for healthy individuals.  Protein restriction leads to protein catabolism, muscle breakdown and increases the likelihood of hepatic encephalopathy.

Additional references:

  • -Age Ageing 2010; 39: 412-23.  Sarcopenia consensus definitions in older people.
  • -Gastroenterology 2008; 134: 1741. Evaluation and management of end-stage liver disease in children. Recs vaccines due to functional asplenia/portal hypertension at age 2 for Neisseria (MCV4) or polysaccharide (MPSV4); at 6 weeks of age for pneumococcal conjugate vaccines. Reviews nutrition, varices, ascites, encephalopathy….
  • -Liver Transplant 2008; 14: 585-591. Poor growth often due to growth hormone resistance. Chronic malnutrition is a factor, but children with advanced liver dz may not grow despite adequate calories. Recs: for chronic liver dz: 130-150% of RDA based on ideal body wt; in infants 120-150 cal/kg/day. Increase MCT either thru formula or supplemental MCT.
  • -Liver Transplant 2006; 12: 1310. Review article on nutrition for OLTx patient.
  • -JPGN 2000; 30: 361. nutrition review and chronic liver disease.