How long does it take for the anesthetic to wear off after de-sexing a female cat?

Female cat de-sexing hospitals currently use respiratory anaesthesia, which reduces the amount of residual anaesthetic in the cat’s body and usually wears off within 20-40 minutes after surgery. If the cat is de-sexed using injectable anaesthesia, the anaesthetic will take a little longer to wear off, some up to about 1 hour.