title: Observations on the patterns of 24-hour energy expenditure changes in body composition and gastric emptying in head-injured patients receiving nasogastric tube feeding.
abstract: BACKGROUND
  Although intolerance to nasogastric feeding is commonly observed after head injury, quantitative measurements of gastric emptying are lacking. Concepts about energy requirements are limited by the lack of long-term measurements of total energy expenditure.
  
  
  METHODS
  Six male subjects with severe head injury had their gastric emptying measured by the phenol red technique. N and energy balances were measured by classic balance techniques, which included continuous indirect calorimetry for up to 24 hours (days 3 to 5). Measurements of body composition were made on days 3 to 5 and 12 to 19 (4 subjects only).
  
  
  RESULTS
  The subjects lost a mean of 9.8 kg of which 2.3 kg was estimated to be due to fat (equivalent to -14 g N/d and -1690 kcal/d). On days 3 to 5, basal metabolic rate (BMR) was 130% to 135% of predicted. The low dietary intake (650 kcal and 4.2g N/d) was associated with negative energy (-1710 +/- 520 kcal/d) and N balances (-19 +/- 5 g N/d). Gastric emptying was delayed twofold (days 3 to 5) compared with controls (p < .001) and was associated with significant regurgitation of feed into the mouth (16 of 31 saliva samples contained glucose at a concentration of > 0.5 mmol/L compared with control values of < 0.2 mmol/L.
  
  
  CONCLUSIONS
  The large negative energy balance in the subjects studied was largely due to the inadequate nasogastric feeding, which was associated with a twofold reduction in the rate of gastric emptying and frequent regurgitation of feed. The large negative N balance and the high contribution of protein oxidation to total energy expenditure (25% to 28%) was predominantly due to the injury sustained and immobility. An increase in BMR is not necessarily associated with increased total energy expenditure or energy requirements.
authors.affiliation: Addenbrooke's Hospital, Cambridge, UK.
authors.forename: E
authors.initials: E
authors.lastname: Weekes
authors.forename: M
authors.initials: M
authors.lastname: Elia
mesh_terms: D000293:Adolescent; D000328:Adult; D001481:Basal Metabolism; D001823:Body Composition; D006259:Craniocerebral Trauma / Q000503:physiopathology* / Q000628:therapy; D004734:Energy Metabolism; D004750:Enteral Nutrition; D005746:Gastric Emptying; D005764:Gastroesophageal Reflux; D006801:Humans; D008297:Male; D009584:Nitrogen / Q000378:metabolism
chemical_list: D009584:Nitrogen