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Recommendations Summary

CI: Impact of Environmental Factors on RMR Measurement: Noise, Lighting and Temperature 2006

Click here to see the explanation of recommendation ratings (Strong, Fair, Weak, Consensus, Insufficient Evidence) and labels (Imperative or Conditional). To see more detail on the evidence from which the following recommendations were drawn, use the hyperlinks in the Supporting Evidence Section below.

  • Recommendation(s)

    CI: Impact of Environmental Factors on RMR

    Ensure that the room is comfortably quiet, and the light is not providing heat or discomfort for the patient. Noise and light may cause erroneous measures of RMR if the critically ill patient's state of rest is disturbed.

    Rating: Consensus

    CI: Impact of Room Temperature on RMR

    Recommend a room temperature 20 to 25 degrees Celsius (68 to 77 degrees Fahrenheit). When the room's temperature is too cold, RMR is overestimated in critically ill patients by shivering or non-shivering thermogenesis, as the body adapts.

    Rating: Weak

    • Risks/Harms of Implementing This Recommendation

      No potential risks and harms are associated with the application of this recommendation.

    • Conditions of Application

      • Potential barrier: If the ambient temperature in the ICU is low, it will be difficult to measure RMR accurately
      • It may not be possible to change environmental temperature in the ICU, but use of a light blanket may be helpful to eliminate the impact of the low room temperature.

    • Potential Costs Associated with Application

      No obvious costs are associated with the application of this recommendation.

    • Recommendation Narrative

      Room Temperature

      • Resting metabolic rate is affected to variable degrees by moderate cold exposure or ambient room temperatures outside a comfortable zone (22 to 25°C or 72 to 75°F), according to one positive quality repeated-measures study (Van Ooijen et al,  2004)
        • In this study of 10 women and 10 men (19 to 36 years with BMI of 17kg/m2 to 32kg/m2), the individual change in RMR after three hours of exposure to moderate cold (15°C or 59°F), compared to RMR at typical ambient temperature, ranged from a decrease of 4% to an increase of 30% in winter and from a decrease of 12% to an increase of 24% in summer.
      • Two neutral quality narrative reviews recommend RMR measurement in a thermoneutral temperature room (Feurer and Mullen,  1987; McClave and Snider,  1992)
      • It is the consensus of the expert panel that at temperatures within the usual zone of comfort for humans, no changes in RMR, based on adjustment to ambient temperature, are observed.

      Noise and Light

      • There were no primary research studies that addressed the effects of ambient noise and lighting on RMR in healthy adults
      • Two neutral quality narrative reviews, however, suggest that the room should be quiet and lighting mild when measuring RMR for patients in critical care settings (Feurer and Mullen,  1987; McClave and Snider,  1992)
        • These conditions logically extend to other settings.

    • Recommendation Strength Rationale

      CI: Impact of Environmental Factors

      • There was only one positive quality study available to evaluate.

        • Reviews generally recommend a thermoneutral environment, but with no evidence basis
        • Conclusion statement is Grade III.

      CI: Impact of Room Temperature

      • The recommendation is based on two reviews, but no primary research studies.

        • Conclusion statement is Grade IV.