Full title: The Stimulation Ventilation Study

Aim: to see if using magnetic stimulation to mimic normal breathing can reduce the loss in diaphragm strength that occurs when patients are mechanically ventilated.

Background: Some patients come into hospital so sick that they are unable to breath adequately for themselves. The only way to keep them alive is to put them on a ventilator and let the machine take over breathing for them. When they are well enough to start breathing for themselves which is usually days or weeks later, they then have to start a period of weaning from the ventilator to gain back lost strength in the breathing muscles before they are able to breathe on their own without the help of the ventilator.

It is well recognized that being on a ventilator results in weakness of the breathing muscles, the longer one is on a ventilator, the weaker the muscles become. Various cellular pathways through which this occurs have been demonstrated but as yet there is little in the way of methods to prevent or treat it.

The longer a patient spends on a ventilator the more likely they are to die.

We therefore try to wean patients from these ventilators as soon as possible but with current modes of ventilation this is often not quick enough.

If we are able to prevent or even reduce the magnitude of loss of diaphragm strength when patients are mechanically ventilated it follows that they will be able to breathe for themselves without help from the ventilator sooner and hence wean quicker.