Body Composition Study in Critically Ill Patients
Condition: Critical Illness; Muscle Loss
MeSH terms: Critical Illness
Study type: Observational

Summary: 
      This is a single-center prospective observational study that aimed to describe the trajectory
      of change in body composition among critically ill patients who were able to function
      independently prior to admission. Ultrasound measurement of the quadriceps muscle and
      bioelectrical impedance analysis will be conducted at baseline, day 7, day 14 and before ICU
      discharge. The relationship between the change of body composition and clinical outcomes,
      activities of daily living and quality of life at 6-month post ICU admission will be
      investigated. Further, the association between nutritional (energy and protein) intake and
      change in body composition will also be investigated.
    

Detailed description: 
      Malnutrition is associated with poor clinical outcomes. Nutritional status is closely linked
      with body lean mass, specifically the skeletal muscle. Several tool s had been suggested to
      determine nutrition risk and status for critically ill patients such as The Nutrition Risk in
      Critically Ill (NUTRIC) and subjective global assessment (SGA). However, they are surrogate
      (NUTRIC) or subjective (SGA) measures of nutritional status. Ideally, clinicians should
      measure muscle directly to determine the patient nutritional status. Several imaging
      techniques allow direct and accurate measurement of muscle mass, these include magnetic
      resonance imaging (MRI) and computed-tomography (CT). However, the measurement of MRI and CT
      involves the transfer of patients out of the intensive care unit or expose the patient to
      radiation (CT) and therefore it is not justifiable to conduct MRI or CT for the sole purpose
      of measuring body composition. Ultrasound and bioelectrical impedance analysis (BIA) are
      non-invasive and can be conducted at the bedside and therefore are promising techniques in
      assessing patients' nutritional status. Ultrasound measurement of quadriceps thickness and
      rectus femoris cross-sectional area can measure muscle directly and are widely used in the
      research setting. BIA phase angle is a direct measure of cell integrity and is an independent
      predictor of mortality in the ICU.

      This study aimed to describe the trajectory of change in body composition and investigate the
      relationship of the changes with clinical outcomes and activities of daily living and quality
      of life at 6-month post ICU admission. Further, the association between nutritional (energy
      and protein) intake and change in body composition will also be investigated to determine if
      the ultrasound or BIA measurements of body composition can help to assess the response to
      nutritional intervention.
    

Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Adult mechanically ventilated critically ill patients who are expected to stay at least 96
        hours in the intensive care unit.
      
Keywords: Critical Illness; muscle; mortality