RT Journal Article SR Electronic T1 Evaluation of the Inspiratory Pressure Using a Digital Vacuometer in Mechanically Ventilated Patients: Analysis of the Time to Achieve the Inspiratory Peak JF Respiratory Care FD American Association for Respiratory Care SP 257 OP 262 DO 10.4187/respcare.01228 VO 57 IS 2 A1 Leonardo Cordeiro de Souza A1 Cyro Teixeira da Silva, Jr A1 Jocemir Ronaldo Lugon YR 2012 UL http://rc.rcjournal.com/content/57/2/257.abstract AB BACKGROUND: The measurement of the maximal inspiratory pressure (PImax) is of great importance in choosing the time for the start of weaning. OBJECTIVE: To measure the inspiratory pressure in mechanically ventilated patients suitable for weaning to determine the point at which the PImax is achieved within 60 seconds of observation, and analyze factors associated with PImax values. METHODS: Measurement of PImax was accomplished with a digital vacuometer with a unidirectional valve, which allows only exhalation (PImaxUV). With this technique, values are registered and stored, remaining accessible whenever necessary. All patients were on mechanical ventilation, and met the criteria recommended by the American Thoracic Society/European Respiratory Society in 2007 to undergo weaning trial. RESULTS: Eighty-four from the 87 enrolled patients completed the test. No patients reached the PImaxUV in the first 20 seconds of observation. PImaxUV was achieved between 20.1 and 40 seconds in 12 patients (14.0%), and between 40.1 and 60 seconds in 72 cases (86.0%). In a multivariate analysis model in which age, sex, days of mechanical ventilation, APACHE score, and respiratory drive (measured as airway-occlusion pressure 0.1 s after the start of inspiratory flow [P0.1]) were included, only age (P = .006) and P0.1 (P = .003) were significantly associated with the values of PImaxUV. CONCLUSIONS: Within an observation period of 60 seconds, the majority of patients reached the maximal inspiratory peak between 40.1 and 60 seconds. Older patients were found to have lower PImaxUV values, whereas higher values for P0.1 strongly correlated with higher PImaxUV values. These findings are potentially useful to improve successful weaning prediction in the future, but further studies are needed to better clarify this issue.