What is the best method to assess calorie needs in critically ill patients? What are the factors that need to be considered before the test is ordered?

Question

What will be an ideal response?

Answer 1

The gold standard is to get weekly indirect calorimetry studies to assess nutritional needs and adequacy of feeding.
• Patient must have rested in a supine position for a minimum of 30 min.
• Measurement should be done in a quiet, thermo-neutral condition (for example, should not be done if room temperature is increased for any reason).
• Routine nursing care, therapies, and family visitation should be completed 30 minutes before the study (these are not allowed during the study).
• If patient needs pain or agitation control, he/she should be treated 30 minutes before the study and this information should be documented.
• If patient is on mechanical ventilation, FiO2 should be <0.6.
• Must have stable, non-fluctuating FiO2 (variation should be <0.01).
• Ventilatory settings are not changed for 90 minutes before the study is initiated.
• Air leaks from the system should be avoided (ETT/trach cuff leak, chest tube leak, or bronchopleural fistulas).
• Patients who are not on mechanical ventilation should be able to tolerate room air (all sources of supplemental oxygen, i.e., nasal canulas, masks, or trach collars should be turned off during the study).
• Enteral and parenteral nutrition should have been infused at goal rate for the past 12 hours without any change in regimen and infusion should continue through the study.
• If patient is on bolus or cyclic nutrition or on a diet, study should be done approximately an hour after feeding/eating.
• Patient should not have received general anesthesia for the past 6-8 hours.
• For patients on scheduled hemodialysis, study should be done on non-dialysis days. If patient is on PRN dialysis regimen, the study may be done 4 hours after the completion of the treatment.
• Study should be delayed for an hour after burn dressings or other painful procedures.