IMT in mechanical ventilation: suitable protocols and endpoints


Inspiratory muscle training in mechanical ventilation: suitable protocols and endpoints, the key to clear results – a critical review

Silva, Paulo Eugênio

This research from Faculdade de Educação Física, Universidade de Brasília looked into whether Inspiratory Muscle Training (IMT) led to a shorter duration of mechanical ventilation, improved weaning success, or improved survival.

The purpose of this critical review was to determine:

1. What is the ideal prescription of IMT for patients on MV?
2. What is the best time to measure treatment effect?
3. Which kind of device should be used to IMT?
4. What are the best endpoints to evaluate the effects of IMT on the process of discontinuing from MV?

Which kind of device should be used to IMT? POWERbreathe K-Series.

“The biggest challenge in the training of mechanically ventilated patients is the use of conventional devices to impose loads on the respiratory muscles. When training starts, the patient must be disconnected from the ventilator and the respiratory monitoring is lost.”

“A new class of device is now available that is possible to monitor respiratory variables during the training. One example of this is the POWERbreathe K-Series (POWERbreathe-HaB UK) an electronic K-device with feedback software that helps professionals to understand what is happening with patients during their training. This device provides automatically processed information on external inspiratory work. Moreover, power and breathing patterns during loaded breathing tasks is shown, thus the onset of fatigue can be detected earlier.”

“POWERbreathe K-Series was externally evaluated by Belgian researchers and they concluded that the K-Series technology provides automatically processed and valid estimates of physical units of energy during loaded breathing tasks. Recently, de Souza et al. published a case report showing good results using the same technology to train a prolonged mechanically ventilated patient.”

“Another great advantage of this kind of technology is the capacity of load adjustment (1 cmH2O per 1 cmH2O) reaching 3 to 200 cmH2O. Beyond that, the device can adjust the load dynamically, imposing higher load at the beginning of inspirations and lower load close to vital capacity. Thus, a greater range of motion can be reached improving the effectiveness of the training.”


“This review demonstrated the necessity of new RCTs despite of some well designed RCTs have already been published. Many evidences point out that a high intensity training with loads ≥ 50% of MIP in 5 to 6 sets, aiming to reach thirty breathes, one or twice a day, seven days per week is a suitable protocol to improve performance on mechanical ventilation. Patients must be trained at least for two weeks in order to IMT promotes clinically significant effects. It is possible, that outcomes such as the onset of weaning process, duration and success on the weaning, have higher correlation with IMT.” “In conclusion, IMT on mechanically ventilated patients seems to be a promissory treatment despite controversial results. RCTs should be carried out to verify the efficacy of the high intensity training during a suitable period of training using electronic kinetic devices in mechanically ventilated patients.”

Read Inspiratory muscle training in mechanical ventilation: suitable protocols and endpoints, the key to clear results – a critical review