Inspiratory Muscle Training in Patients with Prolonged Mechanical Ventilation: Narrative Review.

This is a narrative review, not a systematic review or original trial, so it does not show how the cited studies were selected or how much confidence to place in each conclusion. Much of the mechanistic evidence comes from animals, post-mortem human tissue, or small clinical reports, so it explains diaphragm weakness but does not prove a training protocol works for every ventilated patient. Not all training studies were positive: a ventilator-trigger training study found no significant difference in maximal inspiratory pressure, weaning duration, or reintubation. Post-weaning training improved strength and quality of life but did not change reintubation, post-ICU length of stay, or readmission. An intervention group had higher hospital mortality, attributed to underlying critical illness, so safety cannot be assumed from the absence of direct adverse events. Phrenic nerve stimulation requires invasive procedures, and transvenous pacing is not yet approved for commercial use, so it is not a standard therapy option.

One author is an external consultant for Lungpacer, which is developing an intravenous phrenic nerve pacing system.

Do not conclude that inspiratory muscle training reliably improves all weaning outcomes. The review reports positive studies, but a training study found no significant difference in maximal inspiratory pressure, weaning duration, or reintubation, and post-weaning training did not change reintubation, length of stay, or readmission.