BACKGROUND: Although there are situations requiring mechanical ventilation (AVM), withdrawal (weaning) should occur as soon as possible, and the spontaneous breathing test (SBT) is a useful tool to shorten and reduce the risks. There are many ways to implement the SBT, however, in patients with heart disease, the most effective one seems to be associated with pressure support (PSV) and positive pressure at the end the expiration (PEEP). OBJECTIVE: To analyze, at the beginning and the end of the SBT in the PSV mode, the behavior of hemodynamic, respiratory and blood gas variables in patients with heart disease. METHODS: 22 cardiac patients underwent to SBT for 30 minutes, of which five were excluded and 17 were able to complete the test. For measurement of inspiratory muscle strength and respiratory mechanics, it was evaluated immediately before SBT: initial inspiratory pressure and maximal inspiratory, airway resistance, static compliance and dynamic, then the assessment of tidal volume, respiratory rate, arterial blood gases and hemodynamics parameters. All parameters were reassessed at the time 30 minutes after the SBT. RESULTS: The values treated in the statistical analysis of these variables showed no significant difference, only the index of weaning showed significant variation (p = 0.011). CONCLUSION: Through this study, it was noted that most cardiac patients undergoing to SBT using PSV remained in stable hemodynamic, respiratory and blood gas. Moreover, it was noticed that about 82% were successful at weaning, suggesting that PSV is a safe and effective method in AVM interruption. However, due to small sample size the development of similar studies is needed.
Weaning; Mechanical ventilation; Assessment
