Influence of Skeletal Muscle Paralysis on Metabolism in Hypothermic Patients After Cardiac Arrest

• Change of resting energy expenditure compared to baseline at 33C° [ Time Frame: initial 72h after cardiac arrest at defined temperatures or timepoints: 1) 33°C 2) 34.5°C 3) 36 °C 4) 36.5 - 37.5 °C 5) after 48-72h ] [ Designated as safety issue: No ]

  resting energy expenditure will be assessed with indirect calorimetry at different measurement time points:

  1. 12-24 h after initiation of mild hypothermia (33C°)
  2. during warming up (at 34.5°C)
  3. during warming up (at 36°C)
  4. during warming up (at 36.5°C - 37.5°C)
  5. normal Temperature, after 48 - 72 h after initiation of mild hypothermia
  
  

• Change of substrate oxidation rate (protein, fat and glucose) compared to baseline at 33C° [ Time Frame: initial 72h after cardiac arrest at defined temperatures or timepoints: 1) 33°C 2) 34.5°C 3) 36 °C 4) 36.5 - 37.5 °C 5) after 48-72h ] [ Designated as safety issue: No ]

  substrate oxidation rates will be assessed with indirect calorimetry at different measurement time points:

  1. 12-24 h after initiation of mild hypothermia (33C°)
  2. during warming up (at 34.5°C)
  3. during warming up (at 36°C)
  4. during warming up (at 36.5°C - 37.5°C)
  5. at normal Temperature, after 48 - 72 h after initiation of mild hypothermia
  
  

• Difference in resting energy expenditure between patients with favorable and unfavorable outcome [ Time Frame: initial 72h after cardiac arrest at defined temperatures or timepoints: 1) 33°C 2) 34.5°C 3) 36 °C 4) 36.5 - 37.5 °C 5) after 48-72h ] [ Designated as safety issue: No ]

  resting energy expenditure will be assessed with indirect calorimetry at different measurement time points:

  1. 12-24 h after initiation of mild hypothermia (33C°)
  2. during warming up (at 34.5°C)
  3. during warming up (at 36°C)
  4. during warming up (at 36.5°C - 37.5°C)
  5. normal Temperature, after 48 - 72 h after initiation of mild hypothermia
  
  
• Difference in substrate metabolism between patients with favorable and unfavorable outcome [ Time Frame: initial 72h after cardiac arrest at defined temperatures or timepoints: 1) 33°C 2) 34.5°C 3) 36 °C 4) 36.5 - 37.5 °C 5) after 48-72h ] [ Designated as safety issue: No ]

  substrate oxidation rates will be assessed with indirect calorimetry at different measurement time points:

  1. 12-24 h after initiation of mild hypothermia (33C°)
  2. during warming up (at 34.5°C)
  3. during warming up (at 36°C)
  4. during warming up (at 36.5°C - 37.5°C)
  5. at normal Temperature, after 48 - 72 h after initiation of mild hypothermia
  
  

Mild hypothermia improves neurological outcome after cardiac arrest. Neuromuscular blockers are in use, together with analgesia and sedation, during the cooling process in many centers to prevent shivering. However, neuromuscular blockers are accused to be associated with various side effects causing serious harm and/or leading to prolonged ICU stay. Furthermore, the use of neuromuscular blockers may mask epileptic activity. Therefore, the advantages and disadvantages of neuromuscular blockers during therapeutic hypothermia need to be re-evaluated.

Aim of this study is to investigate if continuous application of neuromuscular blockers is necessary to prevent shivering and thereby avoiding an increase in energy expenditure in patients during therapeutic hypothermia and rewarming after cardiac arrest (initial 72h).