Abstract
Background: In ventilator-dependent ICU patients, inspiratory muscle training may improve inspiratory muscle strength and accelerate liberation from the ventilator, but optimal training parameters are yet to be established and little is known about the impact of inspiratory muscle training on quality of life or dyspnea. Thus we sough to ascertain whether inspiratory muscle training, commenced while ventilator-dependent, would improve outcomes for ICU patients invasively ventilated for 7 days or longer.Methods: In this randomized trial with assessor-blinding and intention-to-treat analysis, 70 participants (mechanically ventilated ≥7 days) were randomized to receive once- daily supervised high-intensity inspiratory muscle training with a mechanical threshold device in addition to usual care, or usual care (control). Primary outcomes were inspiratory muscle strength (maximum inspiratory pressure % predicted) and endurance (fatigue resistance index) at ventilator-liberation and 1 week later, and quality of life (SF-36v2, EQ-5D). Secondary outcomes included dyspnea, physical function, duration of ventilation and in-hospital mortality.Results: 33 participants were randomly allocated to the training group and 37 to control. There were no statistically significant differences in strength (maximum inspiratory pressure) (95% CI -7.4 to 14.0) or endurance (fatigue resistance index) (95% CI -0.003 to 0.436). Quality of life improved significantly more in the training group than control (EQ5D 17.2; 95% CI 1.3-33.0) (SF36-PCS 6.97; 96%CI 1.96-12.00). Only the training group demonstrated significant reductions in dyspnea (-1.5 at rest, -1.9 during exercise). There were no between-group differences in duration of ventilation or other measures. In-hospital mortality was higher in the control group than the training group (9 vs 4, 24% vs 12%, p=0.23).Conclusions: In ventilator-dependent patients, mechanical threshold loading inspiratory muscle training improves quality of life and dyspnea, even in the absence of strength improvements or acceleration of ventilator liberation. Trial registration: ACTRN12610001089022 https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=12610001089022Trial protocol: http://bmjopen.bmj.com/content/2/2/e000813.full
Does Mechanical Threshold Inspiratory Muscle Training Promote Recovery and Improve Outcomes in Ventilator-Dependent ICU Patients? The IMPROVE Randomised Trial.
