@article {Smithrespcare.02053, author = {Barbara Kellerman Smith and Andrea Gabrielli and Paul W. Davenport and A. Daniel Martin}, title = {Effect of Training on Inspiratory Load Compensation in Weaned and Unweaned Mechanically Ventilated ICU Patients}, elocation-id = {respcare.02053}, year = {2013}, doi = {10.4187/respcare.02053}, publisher = {Respiratory Care}, abstract = {Background: While inspiratory muscle weakness is common in prolonged mechanical ventilation, inspiratory muscle strength training (IMST) can facilitate strengthening and ventilator weaning. However, the inspiratory load compensation (ILC) responses to threshold loads are not well-characterized in patients. The purpose of this study was to retrospectively compare ILC responses according to the clinical outcomes of IMST (i.e. maximal inspiratory pressure (MIP), weaning outcome), in difficult to wean ICU patients. Methods: Sixteen tracheostomized patients (weaned = 10, unweaned = 6) from a previous clinical trial underwent IMST 5 days/week at the highest tolerated load, in conjunction with daily, progressive spontaneous breathing trials. MIP and ILC of a 10 cm H2O load were compared in the subjects before and after IMST, using repeated measures ANOVA. Changes in ILC performance were further characterized (5, 10, 15 cm H2O loads) in the trained patients who weaned. Pearson correlation identified relationships between MIP and ILC. Results: Demographics, respiratory mechanics and initial MIP (52{\textpm}26 vs. 42{\textpm}13 cm H2O) did not significantly differ between groups. Upon enrollment, MIP significantly correlated with flow ILC responses to the 10 cm H2O load (r=0.638, p\<0.01). After IMST, MIP significantly increased in the entire sample (p\<0.05). Both before and after IMST, subjects who weaned generated greater flow and volume ILC than patients who failed to wean. Additionally, ILC flow, volume and duty cycle increased upon ventilator weaning, at loads of 5, 10 and 15 cm H2O. Conclusions: Flow ILC at a threshold load of 10 cm H2O in ventilated, tracheostomized patients positively correlated with MIP. Although MIP improved in both groups, flow and volume ILC responses of weaned subjects were more robust, both before and after IMST. The results suggest ILC responses are different in weaned and unweaned patients, reflecting dynamic inspiratory muscular efforts that could be influential to weaning. Further study is needed.}, issn = {0020-1324}, URL = {https://rc.rcjournal.com/content/early/2013/06/13/respcare.02053}, eprint = {https://rc.rcjournal.com/content/early/2013/06/13/respcare.02053.full.pdf}, journal = {Respiratory Care} }