Spinal anaesthesia is a very commonly used form of regional anaesthetic which involves blocking the nerves that supply the area where the surgeon will be operating. This reduces the number of anaesthetic drugs required which in turn reduces the side effects - feeling sick for example. With a spinal anaesthetic the nerves to your legs and abdomen are affected allowing surgery in these areas. Sometimes a spinal anaesthetic alone without a general anaesthetic or with sedation will be used. Your anaesthetist will discuss this with you.
Performing a spinal anaesthetic takes only a few minutes and is associated with minimal discomfort. It involves having a single shot injection in your lower back. The anaesthetist numbs the area beforehand to make the injection less uncomfortable. You will be either asked to lie on your side or sit on the edge of the bed whilst your anaesthetist is performing the spinal (see picture's right). After the injection you may be aware of a warm sensation in your legs or bottom and your legs will feel increasingly heavy and difficult to lift. Your anaesthetist will check the adequacy of the numbness before surgery starts. The numbness and altered sensation can last for up to 18 hours, which is also the length of the pain relief that a spinal provides.
The risks of having a spinal anaesthetic include:
- Insufficient block
- Nerve damage
- Drop in blood pressure
- Inability to pass urine whilst spinal is working
There are some medical reasons why your anaesthetist may not be able to perform this anaesthetic, but this will be discussed with you.