Simple _Saandfe:

by Michael Munn

Mike Munn, using an oral mask.

Editor’s note: In the last issue of Quest, Diane Huberty told readers why she was happy with getting her breathing assistance (ventilation) through a tracheostomy tube with a volume ventilator (see “Truth, Lies and Tracheostomies,” July-August). In the following article, Michael Munn tells readers why he prefers having a mask or mouthpiece with the same type of ventilator.

The February morning began pretty much like any other — shower, dressing, breakfast, and then to my desk at home. But what happened around 10 a.m. was not like any other morning. I felt shorter and shorter of breath. I was moments away from calling 911 when I relaxed and began to breathe more easily.

Over the next few months, though, things got worse. At one point, while we were shopping in a mall, my wife left me momentarily. She returned to find me slumped over in my wheelchair, barely conscious and incoherent. I never would have guessed a breathing problem could cause this. But it can and does.

Having experienced weakness from limb-girdle muscular dystrophy since my teen years, I’d expected to lose the ability to climb stairs, stand up from chairs, stand up from the floor, and even to walk. I fell countless times during all those years. In more than 50 years I’ve had hundreds of falls. But breathing was never a problem.

By the time the summer of 2001 rolled around, it was really serious. Lung tests and overnight sleep tests turned up two problems. The first was that my diaphragm muscles were weakening and easily tired. The second was the discovery that I have central sleep apnea (CSA), a condition in which the brain doesn’t tell the muscles to breathe during sleep. It leaves the body gasping for air, but I didn’t know this was happening.

Starting Out: Noninvasive
Pressure Ventilation

There are basically three options for breathing support — noninvasive pressure ventilation, noninvasive volume ventilation, and invasive (tracheostomy) volume ventilation.

Noninvasive Volume Ventilation Systems Go Beyond ‘BiPAP’

The near-term solution offered to me was nighttime noninvasive pressure ventilation with a mask. You’ll hear these systems referred to as “BiPAP” devices, which stands for “bilevel positive airway pressure,” even though that’s actually just the name of the Respironics brand.

Many patients start with this type of breathing assistance. It may work for moderate respiratory muscle weakness, but it can’t deliver very much air.

With bilevel pressure ventilation, the machine pushes air into the lungs at a constant pressure. It then drops down to a lower pressure to allow breathing out. The pressure pulse always strained my throat and lungs, sometimes painfully. It worked well for my condition because the machine forced me to breathe during times when my brain didn’t tell me to breathe.

My diaphragm muscles also got a good rest during the night. For about a year this all worked. I felt much better during the day — no tiredness, no falling into a semiconscious state, no more slumping over.

Then, I began having more and more difficulty breathing during the day. I wheeled into the bedroom to use the machine every hour or so. It was clear another threshold had been crossed. It was time for something else.

Moving On: Noninvasive
Volume Ventilation

The next step could have been invasive volume ventilation — i.e., ventilation delivered through a tracheostomy (trach) tube, which is surgically inserted through a hole in the trachea (windpipe).

But for me it was noninvasive volume ventilation, delivered through a mouthpiece or mask. My main concerns about tracheostomy systems were the possibility of infections and hospitalization, and the extra burden my trach care would place on my wife.

Volume ventilation delivers a set volume, rather than a set pressure, of air to the lungs, with each “breath.” Volume-cycled ventilators can deliver higher volumes and higher pressures of air than the maximum possible with BiPAP-type pressure-cycled devices. [Editor’s note: Some modern ventilators, such as the Pulmonetics LTV 950 and 1000, can be set to limit either pressure or volume and are more powerful than a BiPAP-type device.]

The only difference between noninvasive and invasive volume ventilation is how the air is delivered. The ventilator is the same.

The first thing I noticed was how much better volume ventilation felt than pressure ventilation. I