Energy and nitrogen balance and changes in midupper-arm circumference with multiple organ failure

Area of Science:

• Clinical Nutrition
• Critical Care Medicine
• Metabolic Research

Background:

• Patients with multiple organ failure (MOF) often require intensive nutritional support via intravenous feeding.
• Assessing nutritional status and requirements in MOF is challenging due to factors like fluid retention.

Purpose of the Study:

• To evaluate the achievement of targeted energy and nitrogen intake in intravenously fed MOF patients.
• To correlate nutrient balance with anthropometric measurements and muscle wasting during illness.

Main Methods:

• Measured energy and nitrogen balance, including urinary nitrogen excretion, in 35 MOF patients.
• Performed serial mid-upper arm circumference (MAC) measurements and muscle biopsies.
• Analyzed nutrient intake against prescribed targets (176 kJ/kg FFM and 0.24 g N/kg FFM).

Main Results:

• Target energy and nitrogen intake were met in only a small fraction of patients (3/35 and 4/35, respectively).
• Muscle biopsies confirmed significant wasting in all patients.
• MAC decrease correlated with wasting, while stable MAC was attributed to fluid retention, masking true nutritional status.

Conclusions:

• Intravenous feeding regimens frequently failed to meet the calculated nutritional needs of MOF patients.
• Standard anthropometric measures like MAC can be misleading due to fluid retention, obscuring actual muscle wasting.
• Effective nutritional management in MOF requires careful monitoring beyond fluid-adjusted anthropometrics.