The next task is to see to your breathing. If the operation does not require muscle relaxation, he may either insert a small curved airway (an oropharyngeal airway) designed to keep your tongue and soft tissues of the neck from obstructing your airway, and hold a mask over your mouth and nose through which you will breathe, or he may insert a device called a laryngeal mask airway. This is a tube attached to an enlarged spoon-like device that is inserted into the back of your throat so that the spoon part fits over your larynx and vocal cords. An expandable cuff is then inflated with air so as to seal the spoon in position in your throat.
If the operation requires that you have to be very relaxed, or if there is an increased risk of aspiration, your anaesthetist will insert an endotracheal tube (ETT). This is a long plastic tube the one end of which is placed in your trachea (windpipe) and the other end (that protrudes from your mouth) is connected to the fresh gas supply coming from the anaesthetic machine. The end of the ETT that is in your trachea has a little cuff that is inflated with air so that your airways are sealed off from the rest of your throat.
To insert the ETT you have to be totally relaxed, so your anaesthetist will paralyse you with a muscle relaxant, and when this is working will look into your throat with an instrument called a laryngoscope. With this he/she is able to see your vocal cords. He/she then gently slips the ETT between them into your trachea, blows up the cuff, and then ventilates you with a bag in the anaesthetic circuit and listens to your lungs to ensure that it is correctly placed in the trachea. He / she will then attach you to the ventilator that breathes automatically for you.
A general anaesthetic
The equipment - the ventilator