Feasibility, safety, and patient acceptability of electronic inspiratory muscle training in patients who require prolonged mechanical ventilation in the intensive care unit: A dual-centre observational study.

BACKGROUND: Inspiratory muscle training (IMT) is an intervention that can be used to rehabilitate the respiratory muscle deconditioning experienced by patients with critical illness, requiring prolonged mechanical ventilation. Clinicians are currently using mechanical threshold IMT devices that have limited resistance ranges. OBJECTIVES: The objective of this study was to evaluate the safety, feasibility, and acceptability of using an electronic device to facilitate IMT with participants requiring prolonged mechanical ventilation. METHOD: A dual-centre observational cohort study, with convenience sampling, was conducted at two tertiary intensive care units. Daily training supervised by intensive care unit physiotherapists was completed with the electronic IMT device. A priori definitions for feasibility, safety, and acceptability were determined. Feasibility was defined as more than 80% of planned sessions completed. Safety was defined as no major adverse events and less than 3% minor adverse event rate, and acceptability was evaluated following the acceptability of intervention framework principles. RESULTS: Forty participants completed 197 electronic IMT treatment sessions. Electronic IMT was feasible, with 81% of planned sessions completed. There were 10% minor adverse events and no major adverse events. All the minor adverse events were transient without clinical consequences. All the participants who recalled completing electronic IMT sessions reported that the training was acceptable. Acceptability was demonstrated; over 85% of participants reported that electronic IMT was either helpful or beneficial and that electronic IMT assisted their recovery. CONCLUSION: Electronic IMT is feasible and acceptable to complete with critically ill participants who require prolonged mechanical ventilation. As all minor adverse events were transient without clinical consequences, electronic IMT can be considered a relatively safe intervention with patients who require prolonged mechanical ventilation.

Does mechanical threshold inspiratory muscle training promote recovery and improve outcomes in patients who are ventilator-dependent in the intensive care unit? The IMPROVE randomised trial.

BACKGROUND: In patients who are ventilator-dependent in the intensive care unit, 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 dyspnoea. Thus, we sought to ascertain whether inspiratory muscle training, commenced while ventilator-dependent, would improve outcomes for patients invasively ventilated for 7 days or longer. METHODS: In this randomised trial with assessor blinding and intention-to-treat analysis, 70 participants (mechanically ventilated ≥7 days) were randomised to receive once-daily supervised high-intensity inspiratory muscle training with a mechanical threshold device in addition to usual care or to receive 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. Secondary outcomes included quality of life (SF-36v2, EQ-5D), dyspnoea, physical function, duration of ventilation, and in-hospital mortality. RESULTS: Thirty-three participants were randomly allocated to the training group, and 37 to the control group. There were no statistically significant differences in strength (maximum inspiratory pressure) (95% confidence interval [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 in the control group (EQ-5D: 17.2; 95% CI: 1.3-33.0) (SF-36-PCS: 6.97; 95% CI: 1.96-12.00). Only the training group demonstrated significant reductions in dyspnoea (-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 in the training group (9 vs 4, 24% vs 12%, p = 0.23). CONCLUSIONS: In patients who are ventilator-dependent, mechanical threshold loading inspiratory muscle training improves quality of life and dyspnoea, even in the absence of strength improvements or acceleration of ventilator liberation.