Can High Intensity Inspiratory Muscle Training Improve Inspiratory Muscle Strength and Accelerate Weaning in Medical Patients With Difficulty on Weaning?

Introduction: It has been described that invasive mechanical ventilation leads to diaphragm weakness. The inspiratory muscle weakness is related with a difficult and prolonged weaning as well as longer duration of mechanical ventilation and increased risk of complications and death. Consequently, the duration of stay in ICU is longer and the costs in ICU increase.

Objectives: To determine the effects of a high intensity inspiratory muscle training (IMT) on inspiratory muscle strength, weaning outcomes, complications and length of stay in the ICU in medical patients with difficulty on weaning and admitted in the ICU.

Methodology: In a single blind randomized clinical trial, 40 tracheotomy ventilated medical patients in which spontaneous breathing trial has failed ≥ 1 time, will be selected and randomized into two equitable groups. In the intervention group, IMT will be performed at 60% of the maximum inspiratory pressure (which will increase by 10% every week) while in the control group it will be performed at 30%. In both groups, 5 sets of 6 breaths will be performed, once a day, 5 days a week, for a maximum of 28 days or until the patient is successfully weaned. The main outcome will be the maximum inspiratory pressure, while the maximum expiratory pressure, weaning duration process, weaning success, duration of mechanical ventilation, length of stay in the ICU, complications and the rapid shallow breathing index will be analyzed as secondary outcomes.

t-student test for independent samples will be used to analyze quantitative outcomes. For qualitative outcomes will be used X2 test. A value of p\<0.05 will be assumed as an indicator of statistically significant results.

Future contributions: Our collect results can be useful for the updating of the clinical practice guidelines and promote its implementation in the clinical practice.


Eligibility Criteria:
Inclusion Criteria:

* Medical patients aged ≥ 18 years hospitalized in the ICU.
* Patients ventilated by tracheostomy and who have failed ≥ 1 spontaneous breathing test.
* Being ventilated in assisted-controlled, assisted or pressure support modes.
* PEEP ≤ 10 cmH2O
* Richmond Agitation-Sedation Scale between -1 and 0.
* Confusion Assessment Method for the Intensive Care Unit negative.
* Cardiorespiratory and hemodynamic stability in the absence of vasopressor support or with minimal requirement (dobutamine or dopamine ≤ 5 μg / kg / min, phenylephrine ≤ 1 μg / kg / min).
* FiO2 ≤ 0,6
* PaO2/FiO2 ratio \> 200
* Blood lactate levels \< 4 mmol/L

Exclusion Criteria:

* Progressive neuromuscular disease
* Thoraco-abdominal surgery in a period \<30 days from the beginning of the study.
* Diseases that cause hemodynamic instability (cardiac arrhythmia, decompensated heart failure, unstable ischemic heart disease).
* Hemoptysis
* Unstable chest wall.
* Not drained pneumothorax
* Phrenic nerve injury
* Spinal cord injury above T8
* Clinical signs of respiratory distress (paradoxal breathing, use of accessory respiratory muscles)
* Body mass index \> 40 kg / m2
* Use domiciliary ventilator support prior to hospitalization.
* Skeletal disorder of the rib cage that impairs its biomechanics (severe kyphoscoliosis, congenital deformities).
* Body temperature \> 38ºC
* Pregnancy
* Receive therapy with nitric oxide or nebulized prostacyclin.
* Medical order.