nail varnish

[Topsie]

I have recently had a small operation which I was under anesthetic for and the nurse asked me before the op if I was wearing any nail varnish. I was just wondering why you should not wear nail varnish during an operation?

Thanks in advance

[~sillycow~]

something to do with checking the colour of your toes and fingers (to do with blood flow i think) to make sure everything is ok

[ursula62]

yep silly is right. They press your fingernails and check how long it takes for the blood to flow back. If you're wearing nailvarnish they can't do this.

[Golem]

It's more likely that they put a Pulse Oximeter on your finger during the operation, the anaesthetist wanted to make sure you were receiving enough oxygen.

This is a small peg that clamps over the end of your finger and shines an infra-red light beam through the nail bed. A sensor on the opposite side measures the amount of absorbed light and works out how much oxygen is passing through the blood vessels. This is called the oxygen saturation level and is measured as a percentage. Anything over about 95% is good, it means that your blood is carrying an adaquate supply; anything less then a patient is given some oxygen just to boost the level up a bit. In acute or chronic situations the oxygen level can drop to seriously low levels; I've seen it down to 75%, at which point the person's level of consciousness is already affected.

Nail varnish blocks the light passing through the finger and gives false readings; which is why we carry nail varnish remover on the ambulances!

[Topsie]

Thank you very much for your answers :)