• Assessment
    Does use of RQ improve accurate macronutrient delivery in critically ill individuals in the Intervention Phase of the Nutrition Care Process?
    How do factors of an individual’s non-adherence with a fasting requirement found in protocol measurements (>/= 4 hours) influence respiratory quotient (RQ)?
    • Conclusion

      In a healthy individual who should have been fasting, measurement of RQ>1.0 should prompt the operator to inquire whether the subject has consumed calories prior to the test, thus violating measurement protocol. A repeated measurement under more optimal conditions should be considered. In critically ill patients, a nonfasting measurement RQ > 1.0 can, but might not always, accurately reflect a true RQ measure and should prompt the operator to rule out excessive feeding or other metabolic and respiratory factors.

    • 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.
    How do factors of unusual metabolic or respiratory conditions influence respiratory quotient (RQ)?
    • Conclusion

      If metabolic and respiratory causes (prolonged fasting, excessive caloric intake, or respiratory difficulty) have been ruled out, an RQ < 0.7 or > 1.0 might indicate that calorimetry equipment has not been calibrated properly or is not working, or that the calorimetry test is not being conducted properly. One study identified 28 of 72 (39%) patients with a RQ error out of range (McClave SA, et al, 2003) and therefore measurement potentially did not accurately reflect true resting metabolic rate.

    • Grade: V
      • 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.
    How do factors of unusual metabolic or respiratory conditions influence respiratory quotient (RQ)?
    • Conclusion

      Under certain metabolic and respiratory conditions (e.g., prolonged fasting, excessive caloric intake, or hypoventilation or hyperventilation), RQ can be less than 0.7 or greater than 1.0 in healthy and ill people.

    • Grade: III
      • 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.