EE: Diurnal (Time of Day) Variation in Critically Ill 2013
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EE: Diurnal Variation in Critically Ill
If the critically ill patient is mechanically ventilated and receiving continuous feedings, then the registered dietitian nutritionist (RDN) may conduct a measurement of resting metabolic rate (RMR) at any time of day, as long as resting conditions can be achieved. Likewise, if a measurement of total energy expenditure (TEE) is being considered, time of day does not need to be taken into account. Research indicates that there is no significant diurnal variation in either RMR or TEE in mechanically ventilated patients receiving continuous feedings. The effect of diurnal variation in critically ill patients who are not mechanically ventilated while receiving continuous feedings is unknown.
Risks/Harms of Implementing This Recommendation
There are no potential risks or harms associated with the application of this recommendation.
Conditions of Application
Recommendation only applies to critically ill patients who are mechanically ventilated and receiving continuous feedings.
Potential Costs Associated with Application
There are no obvious costs associated with the application of this recommendation.
Three studies were included in the evidence analysis for this recommendation:
- One positive-quality non-randomized clinical trial (Frankenfield et al, 1994)
- One neutral-quality cross-sectional study (van Lanschot et al, 1988)
- One neutral-quality validity study (Zijlstra et al, 2007).
Three studies provide evidence that there is no significant diurnal variation in REE or TEE 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.
Recommendation Strength Rationale
Conclusion statement is Grade II.
- Risks/Harms of Implementing This Recommendation
The recommendations were created from the evidence analysis on the following questions. To see detail of the evidence analysis, click the blue hyperlinks below (recommendations rated consensus will not have supporting evidence linked).
What is the effect of time of day (diurnal variation) on metabolic rate in the critically ill population?
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.
References not graded in Academy of Nutrition and Dietetics Evidence Analysis Process