title: Muscle wasting and energy balance in critical illness.
abstract: BACKGROUND
  In nine patients with multiple organ failure ultrasound was able to identify muscle wasting despite the presence of oedema (Campbell et al., J Clin Nutr 62 (1995) 533).
  
  
  OBJECTIVE
  The purpose of the present study was twofold: one was to determine whether this technique was applicable to a much larger ICU population, many of whom were not as ill as the original subjects. The second reason was to determine whether a relationship could be identified between rates of wasting and energy balance.
  
  
  METHODS
  Serial measurements of both mid-upper arm circumference (MAC) and muscle thickness, using ultrasound, were made at 1-3 day intervals between 5 and 39 (median 7) days in 50 critically ill patients.
  
  
  RESULTS
  Muscle thickness decreased in 48 of the 50 patients at a median rate of 1.6%/day with a range of 0.2-5.7%/day. In 33 patients, in whom MAC did not change significantly with time, muscle thickness decreased by between 0.3 and 4.2 (median 1.6)%/day. In three patients MAC increased significantly with time but muscle thickness decreased by between 1.3 and 5.7 (median 2.6)%/day. Twelve patients showed a significant decrease in MAC with time and muscle thickness in this group decreased by between 0.2 and 4.0 (median 1.3)%/day. The percentage decrease in muscle thickness between the groups, in whom MAC decreased or did not change, was not significantly different (P = 0.475).
  
  
  CONCLUSIONS
  We have demonstrated that an ultrasound technique devised to identify muscle wasting in the presence of severe fluid retention works in the majority (48/50) of patients when applied to a wider ICU population. Energy balance made no difference to the rate of wasting.
authors.affiliation: Intensive Care Unit, Hope Hospital, Salford M6 8HD, UK. creid@hhnt.nhs.uk
authors.forename: Clare L
authors.initials: CL
authors.lastname: Reid
authors.forename: Iain T
authors.initials: IT
authors.lastname: Campbell
authors.forename: Rod A
authors.initials: RA
authors.lastname: Little
mesh_terms: D000328:Adult; D000368:Aged; D000886:Anthropometry; D003422:Critical Care; D016638:Critical Illness; D004734:Energy Metabolism; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging*; D009133:Muscular Atrophy / Q000000981:diagnostic imaging*; D013997:Time Factors; D014463:Ultrasonography; D019282:Wasting Syndrome / Q000000981:diagnostic imaging*