Respiratory muscle training for prolonged ventilated patients: a feasibility randomised clinical trial

Purpose

Mechanical Ventilation (MV) is a frequently used potentially life-saving intervention in critically ill patients. A prolonged duration of MV (96 hours or more) contributes to Respiratory Muscle Dysfunction (RMD) in ICU patients. To address RMD, this study compared two methods of respiratory muscle training, and respiratory muscle function was evaluated in prolonged ventilated patients in an acute hospital ICU.

Study Design: Pragmatic, parallel-group, double-blind, randomised clinical feasibility trial.

Methods

24 participants following a period of prolonged mechanical ventilation participated in the study. Participants were randomised to the intervention group (Inspiratory and Expiratory Muscle Training, IEMT) or a control group (Inspiratory Muscle Training, IMT). The principal investigator measured all respiratory muscle outcome measures at baseline and post-intervention.

Results

Both groups found significant improvements in respiratory muscle function after the treatment. No differences between the groups in respiratory muscle function tests after the treatment were found. Exercise adherence exceeded the 70% target (88% adherence). Interventions were feasible and safe with no adverse events. A sample size calculation revealed that 132 patients (66 for each group) are required for a definitive trial.

Conclusion:

The results observed provide evidence that respiratory muscle dysfunction interventions (IEMT/IMT) applied in prolonged MV patients with orygen dual valve respiratory muscle trainer are feasible in terms of safety, outcome measurement and intervention delivery and may contribute to improved respiratory muscle function. A statistically powered study of 132 participants is required. To the investigators’ knowledge, this is the first RCT to investigate the impact of combined IEMT in prolonged ventilated patients. In addition to reporting feasibility and gains in respiratory muscle function, this study also demonstrated that, in the ICU setting, respiratory muscle function could be evaluated non-invasively. Furthermore, combined IEMT/IMT training, which is cost-effective, can be implemented by trained professionals within a healthcare setting.