A Review of Effects of Inspiratory Muscle Training on Clinical and Functional Outcomes of Patients with Mechanical Ventilation

Background and Objectives: This review aims to explore the use of inspiratory muscle training (IMT) in patients with mechanical ventilation (MV). The topics were related to its effect on the duration of MV or weaning, respiratory symptoms or lung function, inspiratory muscle strength (IMS) or endurance, functional ability, and quality of life (QoL).  Methods: Articles published in the last 10 years were reviewed narratively to obtain data about how inspiratory muscle training (IMT) can affect breathing muscle strength in prolonged mechanically ventilated patients. Results: Eleven articles were relevant to the topic, including 7 original articles and 4 systematic reviews. We also found 1 practical guide on IMT in intensive care unit (ICU) patients. Conclusion: Inspiratory muscle weakness is found in most intensive care unit (ICU) patients which further causes difficulty in weaning from MV. No standard protocol exists for the use of IMT in patients who failed to wean from MV. The use of IMT was found to be safe with the incidence of side effects or unexpected events was very small. Several studies found various effects on the success of weaning after IMT administration, such as decreased MV and weaning duration or no effect on these parameters. Studies also found various effects on IMS or endurance although most investigators found increased IMS after IMT administration. These effects vary with exercise intensity and baseline maximum inspiratory pressure (MIP). The IMT program improves lung function thereby reducing symptoms, which in turn leads to improved functional abilities and quality of life (QoL).