This note will cover the concepts surrounding the use of anaesthesia and ideal properties of anaesthesia, both local (LA) and general (GA).
Anaesthetics block all sensation, or consciousness. Analgesia on the other hand blocks pain specifically.
Posology
Posology is the choice of dose, and depends on the following factors:
- Nature of treatment
- Extent of area to be anaesthetised
- Route of anaethesia
- Anatomical region
- Pathological state in patient - tissue infection, cardiac status and BP etc.
- Age and condition of patient.
LA routes of administration
- Epidural This is injection of LA into the epidural space.
- Intrathecal This is injection of LA into the CSF
- Nerve block This is injection into the space around a nerve to block transmission. It should be done upstream to the site of surgery
- Infiltration This is subcutaneous or intradermal.
- Topical Gel.
Local infiltrative vs nerve block
Local infiltrative is prefered for small quick and easy applications. Not good for larger areas.
Nerve block is more skillful and precise, but larger amounts needed. It is preferred in confined spaces.