• Assessment
What is the most accurate method for determination of resting metabolic rate (RMR) in critically ill patients?
• Conclusion
Indirect calorimetry is the standard for determination of RMR in critically ill patients. When indirect calorimetry cannot be performed, predictive formulas may be necessary.

• 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.
What is the most accurate predictive equation for estimating energy needs in critically ill patients with obesity?
• Conclusion
Six studies including individuals with obesity, studied the application of several predictive equations and the use of actual or adjusted body weight.  One study, based on hospitalized patients, reported that the Harris-Benedict equation using actual weight multiplied by a factor of 1.2 (60% of subjects predicted within 10% of RMR) or an adjusted weight multiplied by a factor of 1.3 (67% of subjects predicted within 10% of RMR) resulted in the most accurate predictions.  A second study, based on critically ill, mechanically ventilated patients, reports that the Penn State 2003a equation predicts within 10% of RMR in 61% of subjects, the Penn State 1998 equation predicts within 10% of RMR in 67% of subjects, and the Ireton-Jones, 1992 equations predict within 10% of RMR in 72% of subjects.  Further research is needed in critically ill patients with obesity.

• 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.