The block usually lasts for several hours. Your shoulder will be numb and feel heavy during this time. One advantage of the block is that it reduces the amount of other strong painkillers, such as morphine, needed during and after the operation.
The aim is to numb the nerves to the shoulder, so that you feel no pain during your operation. The block will provide pain relief during the operation and for several hours afterwards. Your anaesthetist will talk to you before doing the block and explain whether you will be awake, asleep or sedated for your operation.
There are a number of benefits. You may have other serious medical conditions, such as heart or lung disease. In this case a general anaesthetic may have slightly more risk than normal. Having the block, instead of a general anaesthetic will cause less stress to your medical condition and be safer.
It is more common to perform a nerve block with a general anaesthetic. This gives excellent pain relief both during and after surgery. This means that the anaesthetist does not need to give as much anaesthetic or strong painkillers. This means a faster recovery and less sickness after the operation.
Are there any alternatives?
There are several alternatives to an interscalene block. These are:
General anaesthetic: You can have your general anaesthetic, where you are completely asleep throughout, but without the interscalene block. Other strong painkillers, like morphine, can be given to keep you comfortable when you wake up.
Local anaesthetic: Sometimes, if the surgery is minor, local anaesthetic injections can be used to numb the operation area only.
If you are to have one of these procedures there is another information leaflet that will tell you more about it.
Who should have it done?
Patients needing surgery on the shoulder can have this type of anaesthetic for their operation.
Who should not have it done?
Each patient has the final decision to proceed or not. If you are unhappy about the procedure for any reason, you should not continue. There are specific medical situations when an interscalene block should not be done and they are as follows:
Medication that prevents your blood from clotting, such as Warfarin; this would lead to more bleeding than normal. Bleeding around the nerves in the neck is a serious problem and must be avoided.
An illness that prevents your blood from clotting, such as haemophilia; this would lead to more bleeding around the nerves in the neck.
Infection of the skin over the site where the needle needs to be put in; this could lead to further infection in the deeper tissues and possibly blood poisoning. This could also cause infection around the nerves.
Unusual or difficult anatomy; this would make it difficult to put the needle in the correct place.
Previous injury or disease affecting the interscalene plexus; perhaps you have had a previous injury to your upper arm, or neck.
Author: Dr Sean White FRCA. Consultant in pain and anaesthesia
© Dumas Ltd 2006