Extubation process in bed-ridden elderly intensive care patients receiving inspiratory muscle training: a randomized clinical trial

BACKGROUND The purpose of this study was to evaluate the extubation process in bed-ridden elderly intensive care patients receiving inspiratory muscle training (IMT) and identify predictors of successful weaning. METHODS Twenty-eight elderly intubated patients in an intensive care unit were randomly assigned to an experimental group (n = 14) that received conventional physiotherapy plus IMT with a Threshold IMT(®) device or to a control group (n = 14) that received only conventional physiotherapy. The experimental protocol for muscle training consisted of an initial load of 30% maximum inspiratory pressure, which was increased by 10% daily. The training was administered for 5 minutes, twice daily, 7 days a week, with supplemental oxygen from the beginning of weaning until extubation. Successful extubation was defined by the ventilation time measurement with noninvasive positive pressure. A vacuum manometer was used for measurement of maximum inspiratory pressure, and the patients' Tobin index values were measured using a ventilometer. RESULTS The maximum inspiratory pressure increased significantly (by 7 cm H(2)O, 95% confidence interval [CI] 4-10), and the Tobin index decreased significantly (by 16 breaths/ min/L, 95% CI -26 to 6) in the experimental group compared with the control group. The Chi-squared distribution did not indicate a significant difference in weaning success between the groups (χ(2) = 1.47; P = 0.20). However, a comparison of noninvasive positive pressure time dependence indicated a significantly lower value for the experimental group (P = 0.0001; 95% CI 13.08-18.06). The receiver-operating characteristic curve showed an area beneath the curve of 0.877 ± 0.06 for the Tobin index and 0.845 ± 0.07 for maximum inspiratory pressure. CONCLUSION The IMT intervention significantly increased maximum inspiratory pressure and significantly reduced the Tobin index; both measures are considered to be good extubation indices. IMT was associated with a reduction in noninvasive positive pressure time in the experimental group.