Duration of anaesthesia


How long will the local anaesthetic effect last?

This depends on the type of local anaesthetic used and the region of the body into which it is injected. Typically, anaesthesia can last several hours but occasionally it can last up to a day, after which it will begin to wear off. You will notice either a return of movement or increase in pain, which is when you will need to take or be given pain relief. This can be done in tablet form or by injection into a muscle or vein.
The risks and complications of this anaesthesia are discussed below. For further information on nerve blocks, http://www.acecc.org.au/page.aspx?A=6534 blocks 


What will I feel during anaesthesia?

All types of anaesthesia are designed to reduce or remove feeling in the part of the body where the procedure is happening.
If conscious sedation is used then patients are able to respond purposefully to verbal commands or light touch. A variety of medications and techniques are available for procedural sedation and/or pain relief. The most common medications given into a vein are benzodiazepines (such as midazolam) for sedation and opioids (such as fentanyl) for analgesia, which decrease the perception/feeling of pain. 

Deep levels of sedation, where consciousness is lost and patients respond only to pain, are associated with reduced ability to maintain an open airway. The anaesthetist will relieve any difficulty with breathing or changes in heart function.
Having general anaesthesia involves the patient being put into a medication-induced state where the patient does not feel pain, and may be associated with changes in breathing and circulation. Under general anaesthesia, a patient is in a state of carefully monitored unconsciousness.

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