title: Effect of neuromuscular blockade on energy expenditure in patients with severe head injury.
abstract: BACKGROUND
  The purpose of this study was to determine the effect of neuromuscular blockade on energy expenditure in severely head-injured patients; to determine the effects of body temperature, nutrition support, and morphine use on metabolic rate; and to compare measured energy expenditure with values from predictive equations.
  
  
  METHODS
  Energy expenditure was measured using indirect calorimetry in 2 groups of ventilated patients-18 with severe head injury during and after administration of pancuronium bromide and morphine, and second, 14 severely traumatized patients without severe head injury (trauma group) who received morphine without neuromuscular blockade.
  
  
  RESULTS
  The mean energy expenditure of head-injured patients increased significantly once pancuronium was discontinued, ie, from 24.2 +/- 3.1 to 28.7 +/- 4.6 kcal/kg (p = .002). This effect was independent of other relevant variables such as morphine dose, body temperature, and nutrition support. When compared with the Harris-Benedict and World Health Organization predictive equations, neuromuscular blockade resulted in a stress factor of only 0.96 and 0.95, respectively, which increased to 1.19 and 1.18, respectively, once blockade was discontinued. Head-injured patients not on neuromuscular blockade had a significantly greater energy expenditure when compared with the trauma group (p = .02).
  
  
  CONCLUSIONS
  Neuromuscular blockade in severely head-injured patients decreases energy expenditure to basal levels, independent of morphine use, body temperature, and feeding. Levels of hypermetabolism in both the head-injured and trauma groups were relatively low, at 19% and 5% above predicted values, respectively. This study provides useful information for the management of nutrition support in severely traumatized patients.
authors.affiliation: Perioperative Services and Critical Care Program, St. Michael's Hospital, Toronto, Ontario, Canada. mccallm@smh.toronto.on.ca
authors.forename: Michele
authors.initials: M
authors.lastname: McCall
authors.forename: Kursheed
authors.initials: K
authors.lastname: Jeejeebhoy
authors.forename: Paul
authors.initials: P
authors.lastname: Pencharz
authors.forename: Richard
authors.initials: R
authors.lastname: Moulton
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000701:Analgesics, Opioid / Q000494:pharmacology*; D000704:Analysis of Variance; D001831:Body Temperature / Q000502:physiology; D015331:Cohort Studies; D006259:Craniocerebral Trauma / Q000378:metabolism* / Q000503:physiopathology*; D004734:Energy Metabolism / Q000187:drug effects*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000494:pharmacology*; D019148:Neuromuscular Blockade; D003473:Neuromuscular Nondepolarizing Agents / Q000494:pharmacology*; D018529:Nutritional Support; D010197:Pancuronium / Q000494:pharmacology*; D011446:Prospective Studies
chemical_list: D000701:Analgesics, Opioid; D003473:Neuromuscular Nondepolarizing Agents; D009020:Morphine; D010197:Pancuronium