Predicting Resting Energy Expenditure in Critically Ill Patients by Measuring Lean Body Mass by US

"Three measurements will be made at each of three sites; mid-upper arm, forearm and thigh anteriorly and the mean value will be calculated. Measurement sites will be marked with indelible ink to ensure day-to-day consistency.~1. Thigh: MLT of the quadriceps femoris muscle (M. Vastus intermedius and M. rectus femoris) will be assessed bilaterally~2. Mid-upper arm: Muscle layer thickness will be measured over the biceps,midway between the tip of the acromion and the tip of the olecranon~3. Forearm: A point midway between the antecubital skin crease and the ulnar styloid was marked and muscle thickness down to the interosseus membrane"

REE will be calculated using indirect calorimetry via metabolic module on General Electric ventilator (Engstrom Carestation and Carescape R860, GE Health care, USA) All indirect calorimetric measurements will be done using standardized technique. Gas calibration will be performed before each measurement, and the measurements will last for at least 30 minutes. Measurements will be taken with the patient lying supine and ventilator settings left unchanged for at least 60 minutes ahead of indirect calorimetry. The REE will be calculated during the first 24 hours of admission to ICU.