Introduction
The Interscalene Brachial Plexus block (ISB) is a regional anesthetic technique used for surgeries of the shoulder and upper arm. It is a safe and effective block that provides both safe and excellent surgical anesthesia and post-operative pain relief. During this block your anaesthetist injects local anaesthetic solution around the major nerves supplying the shoulder and the upper limb.
An Interscalene block is a nerve block in the neck used to either:
1) Provide a heavy numbness in the shoulder and arm (in the same way that a dentist can numb a tooth) so that shoulder surgery can be carried out “awake” or under mild sedation
2) To provide excellent pain relief for shoulder surgery carried out under general anaesthesia.
This ensures that the best post-operative pain relief is achieved and you can go home earlier. Sometimes an Interscalene block alone is used if you would prefer to be awake throughout the operation or if a General Anaesthetic is not suitable.
I will see you before your operation and discuss your anaesthetic with you.
Procedure:
Once you arrive in the anaesthetic room, you will be attached to the usual monitors: a blood pressure cuff, a light sensor to measure your blood oxygen level attached to your finger, and ECG leads placed on your chest. You will receive some sedation through your intravenous cannula prior to placement of the block, which relaxes you and you will likely to have little or no recollection of the block placement.
Next, the anesthetist will cleanse your neck on the operative side with an antiseptic solution. He may ask you to lift your head off the bed or sniff with your nose while examining your neck. These maneuvers help the anesthetist to locate landmarks on the side of your neck that aid in the correct placement of the block needle.
Once the optimum location is found, the anaesthetist will numb the skin with local anesthetic to make the procedure as comfortable as possible. Next he will slowly insert a special insulated needle connected to a nerve stimulator. A very small amount of electrical current will be passed through the needle as the needle is advanced to assist in locating the nerves to your shoulder and arm and optimizing the needle placement. You will feel the sensation of involuntary twitches or movements in your shoulder and arm. Don't try to stop these movements because they tell us if we are in the right location with the needle. When the location and/or response are optimal the anesthetist will inject a large volume of long acting local anaesthetic solution to numb your shoulder and arm. This procedure usually takes only a few minutes to perform.
The block takes approximately 15-20 minutes to work. You will notice shoulder and arm weakness and numbness. There are a small percentage of patients where the block may not work who will receive strong pain killers. You will receive some sedation or a light general anesthetic as it allows better blood pressure control and ultimately more patient comfort.
After the surgery and transport to the recovery room, the sedation will begin to wear off. You may notice few things. First you will have little or no pain. You won't be able to move or feel your shoulder, arm, and sometimes your hand. Rarely, your voice may be hoarse and you may feel like you're not taking as deep a breath as you did before the surgery. You may notice the temporary drooping of the eyelid or numbness in the face on the same side of the block. These are normal expected side effects from the interscalene block and are relatively short lived.
The numbness from the block usually lasts for 6-18 hrs. Occasionally up to 36 hours. It is extremely important that you take regular pain killers at the prescribed times. This is to avoid unpleasant pain at the time when the nerve block begins to wear off.
Management of the “NUMB ARM”
You should carry the “numb” arm in an arm sling until normal sensation and motor function return. You should look after the shoulder and arm – it should be protected from heat or pressure injury and extremes of movement. You should take care not to come in contact with extremely hot or cold items because you will not be able to protect your arm from injuries of extremes of temperature.
Benefits:
The benefits of an interscalene nerve block (ISB) for shoulder surgery are:
· Reduced risk of nausea and vomiting
· Earlier to leave hospital
· Early intake of food and drink
· Excellent pain control
· Lighter general anesthetic with speedier recovery from the anaesthetic
Complications of ISB :
· Punctured lung (pneumothorax) – Due to the needle piercing the lining of the lung causing it to collapse. If it occurs, admission to hospital while it resolves will be necessary. Very rarely a tube has to be placed into the chest to drain the air.
· Seizures and serious long term nerve damage - less than 0.1% risk and reduced by carrying out the nerve block awake/under sedation.
Fortunately, the serious side effects and complications are uncommon and are easily dealt with, with little no after effects.
References:
1. http//www.massgeneral.org/ortho
2. http//www.nysora.com
3. Dr. D. Acharya, Consultant in Anaesthesia
Disclaimer
This website is designed to provide summary of information to the patients. While it is detailed, it does not provide an exhaustive review. The author/owner neither affirms nor denies the accuracy of the information contained herein. No liability will be assumed for the use of this website. Browsers (patients) are strongly urged to consult their anaesthetists prior to having their block.
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