Authors (including presenting author) :
LUI, Pui Sze Grace
Affiliation :
Dietetics Department, North District Hospital
Introduction :
Optimal nutritional provision is crucial in the ICU to prevent under and overfeeding-related complications and ICU acquired weakness. This is often difficult to achieve as most predictive equations have low accuracy and a lack of validated quantitative tools for nutritional assessment and monitoring.
Objectives :
Explored the use of 3 quantitative bedside tools to tackle this problem:
1) Indirect Calorimetry (IC) is the gold standard for estimating energy requirements by measurement of inspired O2 and expired CO2.
2) Nitrogen balance is the calculation of (N2 input- N2 output, target 0-5gN/day). It guides protein requirements to achieve anabolism, allowing the body to build new muscle for survival and rehabilitation.
3) Bioelectrical Impedance analysis derived muscle mass appears a potential biomarker for sarcopenia to evaluate adequacy of nutritional interventions.
Methodology :
This is a case study of a 61-year-old male with Myasthenia Gravis on steroids, lymphoma in remission, admitted to ICU for COVID-19 pneumonia with ARDS. He had difficulty weaning from mechanical ventilation and sedation, severe cachexia and ICU acquired weakness. On initial assessment (ICU Day 47)- IC, Nitrogen Balance and Bioelectrical Impedance were measured for baseline values and were repeated when patient had a condition change (i.e. reduced sedation, increased mobilization, weaned off mechanical ventilation).
Result & Outcome :
IC showed increase in energy requirements from baseline 1445kcal (RQ1.01) to 1598kcal (RQ 0.98) after sedation was weaned off and mobilization commenced. Nitrogen Balance increased from baseline 0.21gN/day to 0.31gN/day after protein provision increased. Bioelectrical Impedance analysis showed improvement in skeletal muscle mass from 15.7kg to 15.9kg, Phase Angle improved from 3.1 to 3.15 after 3 weeks of intervention.
These 3 quantitative tools are useful in guiding clinicians in the nutritional assessment, intervention and monitoring of ICU patients to improve outcomes.
