Power wheelchairs are massively more likely to get a puncture and leave you unable to either get in your vehicle or get home than a van or car is. Mainly because we run along the edges of roads, and on pavements where all the debris such as nails and glass naturally collect.

One good way to reduce punctures and the problems that they cause in a Power Wheelchair is to fit Tubeless tyres as I now do since they are far less likely to be punctured in the first place. 

And IF they are then there is no tube to "pop" like a balloon so they generally get you home even with a nail stuck in them. I have some information on that modification should you be interested on my Modified Power Wheelchair pages. Or my Very modified power wheelchair pages...

But in any case I use a large amount of tyre "puncture proofing fluid" in all of my Mobility Van and Powerchair tyres be they tubeless or tubed. This stuff comes in all types and styles.

The one shown is the one I use in my own vans tyres. Its thin enough to flow evenly and as long as you only add the correct amount doesn't cause wheel balance issues at legal highway speeds. although it does cause minor problems at around 85mph that goes away at about 100 mph and upwards. (Tested in Germany officer)

It does give peace of mind though and it really does work. Some other brands are also good but this one I can personally vouch for. At least its the one I used to use before I fitted special runflat tyres to completely cure the problem! Its called Ultra Seal. Ultra Seal isn't cheap however but being disabled never was. I cant vouch for the cheaper brands.

In power wheelchairs which don't care one bit about balance I use much thicker and more fibrous "off road" tyre sealer.  This one is OKO Off Road Tyre Seal