"VARIABLE-PSV" Study

Evaluation a New Ventilatory Modes: VARIABLE-PSV: a Randomized Controlled Cross-over Study: the " VARIABLE-PSV" Study

Variable PSV is a new ventilatory mode which delivered a pressure support "variable" from 0 to 100% variation of the set PSV level.This study aimed to compare the ventilatory behavior, sleep quality and gas exchange between VARIABLE (or Noisy)-PSV and "standard" (or fixed)-PSV during the weaning phase of critically ill patients who required mechanical ventilation.

Twenty patients will be enrolled. They will be ventilated withVARIABLE-PSV and STANDARD-PSV: for 24 h each in a randomized crossover order. The ventilatory parameters, ventilator/patient asynchrony, gas exchange effects, sleep quality and ventilatory comfort produced by the two ventilation modes will be compared. Before randomisation, a sequence of VARIABLE-PSV will be performed with different level of variation setting to better define the future behavior of the patient under this mode during the 24 h of Variable-PSV.

Inclusion Criteria:

• ventilation planned for more than 48 h
• patient alert and calm corresponding to a Richmond Agitation-Sedation Scale (RASS) between -2 and 0
• Age > or equal 18
• Surrogate decision maker's consent

Exclusion Criteria:

• Clinical instability for any reason.
• Life support withdrawal code
• Patient under tutelage
• Pregnancy
• No French health insurance