How do you know if a salbutamol mdi is empty?

[Janeredgate]

Hi,

I'm a childrens community nurse who is the lead for asthma.

One problem I'm facing is parents using empty mdi canisters and being unsure of when they are empty. Some parents have been told to 'drop their canisters in water', after researching this it appears this is very old fashioned advice.

Does anyone know any up to date research on this? I've been telling parents the only sure way to know is to count their doses as much as possible and if unsure always use a new one.

Be glad of any input.

Thanks,

Jane R.

[Hidden]

If you shake it you can hear the stuff moving around if it is not empty but even this is not accurate. The only way to know is to spray a dose in front of you and see if anything white comes out! This is useful if they are not sure whether they are not responding to their inhaler or whether it has just run out but gives no infomation as to how long it is going to work. Why they cant put a counter on it I don't know. You can get apps on i phones that count but it would be alot simpler if they had one on the device.