Energy Expenditure

EE: Diurnal Variation (2013)

• Assessment
  What is the effect of time of day (diurnal variation) on metabolic rate in the critically ill population?

  • Conclusion

    There is no significant diurnal variation in resting or total energy expenditure in mechanically ventilated, critically ill patients receiving continuous feeding.

    Additional research is needed on critically ill patients who are spontaneously breathing, in the fasted state or being intermittently fed. Additionally, some of the existing research does not mention the level of sedation, so the effect of sedation on diurnal variation in RMR should also be clarified. Only one of three studies examined the diurnal variation in resting as well as total energy expenditure, so new research on diurnal variation should encompass both measures of metabolic rate.

  • Grade: II
    • Grade I means there is Good/Strong evidence supporting the statement;
    • Grade II is Fair;
    • Grade III is Limited/Weak;
    • Grade IV is Expert Opinion Only;
    • Grade V is Not Assignable.
    • High (A) means we are very confident that the true effect lies close to that of the estimate of the effect;
    • Moderate (B) means we are moderately confident in the effect estimate;
    • Low (C) means our confidence in the effect estimate is limited;
    • Very Low (D) means we have very little confidence in the effect estimate.
    • Ungraded means a grade is not assignable.
  • Evidence Summary: What is the effect of diurnal (time of day) variation on metabolic rate in the critically ill population?
    • Detail
    • Quality Rating Summary
      For a summary of the Quality Rating results, click here.
    • Worksheets
      • Frankenfield DC, Wiles II CE, Bagley S, Siegel JH. Relationships between resting and total energy expenditure in injured and septic patients.  Crit Care Med. 1994;22(11):1796-1804.
      • van Lanschot JJB, Feenstra BWA, Vermeij CG, Bruining HA. Accuracy of intermittent metabolic gas exchange recordings extrapolated for diurnal variation. Crit Care Med. 1988; 16 (8): 737-742.
      • Zijlstra N, ten Dam SM, Hulshof PJ, Ram C, Hiemstra G, de Roos NM. 24-hour indirect calorimetry in mechanically ventilated critically ill patients. Nutr Clin Pract. 2007; 22(2): 250-255.
  • Search Plan and Results: EE: Diurnal Variation in Critically Ill Individuals 2012