The Relation Between Quadriceps Muscle Layer Thickness and Nitrogen Balance for Nutrition Monitoring
Condition: Trauma
MeSH terms: Wounds and Injuries
Study type: Observational [Patient Registry]

Summary: 
      Loss of muscle mass is a major cause of intensive care unit-acquired weakness (ICU-AW) and is
      associated with delayed weaning; prolonged ICU and hospital stay and is an independent
      predictor of one year mortality.

      Theoretically, the best strategy to minimize muscle loss during ICU stay, is delivering an
      appropriate nutritional support. Studying the correlation between the sequential assessments
      of quadriceps femoris muscle layer thickness (QMLT) by the aid of Ultrasound in addition to
      the traditional method (NB) for assessment of nutritional status may be helpful to predict
      outcome and mortality.
    

Detailed description: 
      Protein catabolism and proteolysis, mainly in the skeletal muscles is highly accelerated in
      critical illness with severe acute inflammatory processes, such as sepsis, burns, and
      polytrauma patients. The resulting catabolic state may be linked to immunosuppression, poor
      wound healing, and intensive care unit-acquired weakness (ICU-AW), which are associated with
      delayed recovery and increased mortality. In order to prevent muscle-protein depletion,
      several strategies have been proposed. One of them is adequate nutrition. Higher protein
      intake appears to be beneficial and could mitigate the negative catabolic state by increasing
      the availability of exogenous amino acids.

      The adequacy of protein intake could only be optimized by appropriate monitoring. Nitrogen
      balance (NB) is the commonly used tool in this context. It is considered a good marker of
      adequate protein intake, easy, and available method of assessing the success of nutritional
      therapy as it reflects the gain or loss of total body proteins by calculating the difference
      between dietary nitrogen intake and nitrogen losses.

      Moreover, a considerable reduction in muscle mass begins within the first 3 days of ICU
      admission and progressively worsens; therefore quantifying the muscle size may help in
      recognizing patients at risk of ICU acquired weakness and also may guide the interventions to
      prevent this complication. So, it may help in monitoring the adequacy of nutritional therapy
      and protein intake.

      The primary methods that have been explored to measure musculature include computed
      tomography (C.T), magnetic resonance imagining (MRI), ultrasonography (US), and bioimpedance.
      Ultrasonography as a noninvasive, practical, readily available, and bedside technique could
      be considered the first option for the quantification of muscle size in these patients.

      The quadriceps muscle is the most studied muscle found to have strong correlation with muscle
      mass and strength. Its size can be measured by either the quadriceps muscle layer thickness
      (QMLT) or the cross-sectional area (CSA). However, QMLT have greater practicability as
      measurements could be obtained rapidly and in real time as well as it easier to identify than
      CSA.

      Since, monitoring is the key to individualize and optimize the critical protein intake. We
      hypothesized that QMLT evaluation by ultrasound could be used to guide nutritional protein
      intake and is correlated to conventional monitoring with nitrogen balance in critically ill
      trauma patients.
    

Intervention name(s): Ultrasound measurement of quadriceps muscle layer thickness
Intervention type(s): Device
Intervention description(s): With patient in supine position ultrasound will be performed using a 12MHZ Transducer connected to Sonosite M Turbo machine. The probe will be placed perpendicular to the long axis of the thigh on its anterior surface at the two thirds of the length between the anterior superior iliac spine and the upper border of the patella. After identifying the muscle tissue, the thickness of the quadriceps muscle will be obtained by measuring the distance between the cortex of femur and the most superficial muscular fascia. Measurements will be performed by applying maximal compression on the probe without inflicting pain to prevent underestimation of muscle wasting linked to subcutaneous edema. measurements will be made on both sides repeatedly on ICU days 1, 3, 7, and 10. Every time three ultrasound measurements will be taken per site and the average of three measurements for each site will be used and combined to provide total muscle depth
Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Critically ill trauma patients aged between 18 - 60 years of both sexes