Anaesthetic for knee replacement

Knee replacements are painful operations and so we do all we can to make you as comfortable as possible after the operation. Most of our knee replacement patients have a spinal anaesthetic for their operation and if you do then you also have 3 choices to consider.

  1. A General Anaesthetic will allow you to sleep through the operation and you will not remember anything about it.
  2. Sedation allows you to be very relaxed and ‘chilled out’. You will be awake and aware of what is going on although you will feel nothing and your memory of events may be patchy.
  3. Completely awake. The spinal is so powerful that if you want to you can have the operation 100% awake with no sedation at all.

The spinal provides dense numbness from the tummy button downwards so both legs will be completely numb and you will not be able to move them. The numbness means that your body is not ‘aware’ that surgery is going on and so unlike when we do an operation under just a general anaesthetic (and with no spinal), we do not need to give you strong pain killing drugs. These strong pain killers are the drugs which often have unpleasant side effects and can make you feel ill after an operation so it is good to be able to avoid them. The numbness from the spinal will last for about 3-4 hours after which time the sensation and power will return to your legs.

To keep you comfortable once the spinal has worn off, both Mr Qureshi and your anaesthetist will inject large amounts of local anaesthetic during the operation into your thigh and into your new knee joint and this normally keeps our patients fairly comfortable well into the first post operative day.

We start giving you your tablet pain killers before the operation and then you have more in the recovery ward straight after you wake up. The strong pain killers will continue for a couple of days after which we will start to wean you onto weaker pain killers.

Occasionally with a spinal anaesthetic you also need to be catheterized for about 24 hours to prevent you from going into urinary retention (unable to pass urine). We will discuss this with you and if we feel you are high risk of going into retention we will probably suggest we put a catheter in at the time of surgery. For most patients we try and avoid a catheter and only put one in if you are unable to pass urine when back on the ward. Having recently changed the combination of drugs that we put into your spinal, we now need to catheterize far fewer patients.

Please see the following leaflets for more information on your anaesthetic: