Evaluation of Oxygen Consumption and Energy Expenditure During Spontaneous Breathing Trial.

Evaluation of Oxygen Consumption and Energy Expenditure During Spontaneous Breathing Trial - A Randomized Crossover Controled Trial.

The purpose of this study is to compare the oxygen consumption and energy expenditure during the spontaneous breathing trial.

Patients is going to submit to the 2 spontaneous breathing trial ( Automatic tube compensation plus continuous positive airway pressure and continuous positive airway pressure without automatic tube compensation. The oxygen consumption and energy expenditure is going to measure during the spontaneous breathing trial by indirect calorimetry.

Inclusion Criteria:

• IMPROVEMENT OR RESOLUTION OF THE UNDERLYING CAUSE OF DISEASE
• INTUBATED PATIENTS>24h
• PaO2 GREATER THAN 60 mmHg WITH FiO2 LESS THAN 40%
• PEEP=5 cmH2O

Exclusion Criteria:

• CARDIOVASCULAR INSTABILITY
• FEBRILE OR HYPOTHERMIA
• CHEST DRAINAGE
• RESPIRATORY RATE/TIDAL VOLUME RATIO GREATER THAN 105
• PREGNANCY
• FAIL IN THE SPONTANEOUS BREATHING TRIAL
• LEAKS IN THE CIRCUIT
• AGITATION
• NOT ACCEPT PARTICIPATE IN THE STUDY