Resting Energy Needs in Brain Dead Patients (reSting EneRgy nEeds iN brAin DEad Patients)
Condition: Brain Death; Brain Injuries; Brain Edema; Brain Hemorrhage
MeSH terms: Brain Injuries; Brain Death; Brain Edema; Intracranial Hemorrhages; Hemorrhage
Study type: Observational

Summary: 
      The study will examine the resting energy need (REE) in patients suffering from brain damage.
      For the measurement of REE will be used a metabolic computer (which with continuous recording
      of breath-to-breath volume (Vt), respiratory rate (RR) of ventilation per minute volume (MV)
      ), of inhaled and exhaled gases (O2 and CO2) has the ability to calculate the values of VO2,
      VCO2 and with the help of equations the values of REE and RQ.
    

Detailed description: 
      This is a retrospective observational study concerning patients suffering from brain damage.

      All the patients suffering from brain damage are monitored in order to examine their resting
      energy needs (REE). For the measurement of REE the metabolic computer (Medical Graphics,
      Ultima CCM, Minneapolis, USA) is used.

      The main purpose of this study is to reveal the (REE) changing in patients with brain death
      semiology and examine if the REE changes could be related to the outcome of a patient with
      intracranial pathology. Moreover the study will examine if the changes in REE measurement are
      related to changes in flow velocities in the midbrain.

      Any measurement shall be preceded by calibration of the metabolic computer pneumotachograph
      with a 3-liter syringe with an acceptable error of less than 9 ml / lit. The metabolic unit
      is calibrated for VO2 measurements with two calibration cylinders containing 21% and 12% O2
      and for VCO2 measurements with calibration gases containing 5% and 0% CO2 respectively.

      The measurement of flow velocities in the middle cerebral artery will be done with the
      transcranial Doppler using a low frequency (2 MHz) ultrasound head After their final
      diagnosis (brain death or not) the patients' characteristics will be compared according to
      the categorization as "brain dead" or not.
    

Intervention name(s): REE - Resting Energy Expenditure; Transcranial Doppler
Intervention type(s): Diagnostic Test; Diagnostic Test
Intervention description(s): REEs represent 60-70% of the needs for a sedentary person and 50% of physically active people.
For the measurement of REE will be used the metabolic computer (Medical Graphics, Ultima CCM, Minneapolis, USA), which with continuous recording of breath-to-breath volume (Vt), respiratory rate (RR) of ventilation per minute volume (MV) ), of inhaled and exhaled gases (O2 and CO2) has the ability to calculate the values of VO2, VCO2 and with the help of equations the values of REE and RQ.
All patients in the study will be monitored with the metabolic computer. Their measurements will be recorded every day during their stay in the ICU.; The measurement of flow velocities in the middle cerebral artery will be done with the transcranial Doppler using a low frequency (2 MHz) ultrasound head.
All patients entering the study will be examined with the TCD every day during their stay in the ICU.
Observational model: Cohort
Time perspective: Retrospective
Sampling method: Probability Sample
Study population: 
        Adult patients, aged 18-90 years old, entering the ICU, having a GCS <=8 before any
        intervention, having signs of intracranial damage after a traumatic brain injury or a
        cardiac arrest succesfull rescucitation or a brain hemorrhage due to aneurysm.
      
Keywords: Resting energy expenditure (REE); Brain Death; Brain injuries