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Randomized Controlled Trial
. 2016 Sep;71(9):812-9.
doi: 10.1136/thoraxjnl-2016-208279. Epub 2016 Jun 2.

Inspiratory muscle training to enhance recovery from mechanical ventilation: a randomised trial

Bernie M Bissett  1 , I Anne Leditschke  2 , Teresa Neeman  3 , Robert Boots  4 , Jennifer Paratz  5
Affiliations
Randomized Controlled Trial

Inspiratory muscle training to enhance recovery from mechanical ventilation: a randomised trial

Bernie M Bissett et al. Thorax. 2016 Sep.

Abstract

Background: In patients who have been mechanically ventilated, inspiratory muscles remain weak and fatigable following ventilatory weaning, which may contribute to dyspnoea and limited functional recovery. Inspiratory muscle training may improve inspiratory muscle strength and endurance following weaning, potentially improving dyspnoea and quality of life in this patient group.

Methods: We conducted a randomised trial with assessor-blinding and intention-to-treat analysis. Following 48 hours of successful weaning, 70 participants (mechanically ventilated ≥7 days) were randomised to receive inspiratory muscle training once daily 5 days/week for 2 weeks in addition to usual care, or usual care (control). Primary endpoints were inspiratory muscle strength and fatigue resistance index (FRI) 2 weeks following enrolment. Secondary endpoints included dyspnoea, physical function and quality of life, post-intensive care length of stay and in-hospital mortality.

Results: 34 participants were randomly allocated to the training group and 36 to control. The training group demonstrated greater improvements in inspiratory strength (training: 17%, control: 6%, mean difference: 11%, p=0.02). There were no statistically significant differences in FRI (0.03 vs 0.02, p=0.81), physical function (0.25 vs 0.25, p=0.97) or dyspnoea (-0.5 vs 0.2, p=0.22). Improvement in quality of life was greater in the training group (14% vs 2%, mean difference 12%, p=0.03). In-hospital mortality was higher in the training group (4 vs 0, 12% vs 0%, p=0.051).

Conclusions: Inspiratory muscle training following successful weaning increases inspiratory muscle strength and quality of life, but we cannot confidently rule out an associated increased risk of in-hospital mortality.

Trial registration number: ACTRN12610001089022, results.

Keywords: Exercise; Respiratory Measurement; Respiratory Muscles.

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Figures

Figure 1
Figure 1
Inspiratory muscle training via a tracheostomy. Note the flexible tubing connecting the inspiratory muscle trainer to the closed suction device.
Figure 2
Figure 2
Flow of participants through study. ACIF, acute care index of function; CVA, cerebrovascular accident; FRI, fatigue resistance index; ICU, intensive care unit; IMT, inspiratory muscle training; MIP, maximum inspiratory pressure; QOL, quality of life; RPE, rate of perceived exertion; TBI, traumatic brain injury.
Figure 3
Figure 3
Inspiratory muscle changes in both groups: (A) Changes in maximum inspiratory pressure scores before and after intervention. (B) Changes in fatigue resistance index before and after intervention. The box is drawn from the 25th percentile to the75th percentile, and the whiskers are drawn at 1.5 times IQR, with outliers represented with dots. IMT, inspiratory muscle training; MIP, maximum inspiratory pressure
Figure 4
Figure 4
Quality of life and functional measures in both groups: (A) Changes in EQ5D scores before and after intervention. (B) Changes in SF36 scores before and after intervention. (C) Changes in acute care index of function before and after intervention. The box is drawn from the 25th percentile to the75th percentile, and the whiskers are drawn at 1.5 times IQR, with outliers represented with dots. FRI, fatigue resistance index; IMT, inspiratory muscle training
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Comment in

References

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