MAINTENANCE OF ANAESTHESIA
All anaesthetics are constantly being eliminated from the body,
either by being breathed out, metabolized or excreted by the
kidney, so it is necessary to continue to give more drug throughout
anaesthesia. There is no formula for
calculating the amount you need to give. Only by monitoring
the patient’s physiology and responses can you decide
if you need to increase, reduce or maintain the rate of administration
Anaesthesia too light
Check the patient is breathing adequately; retained carbon
dioxide may be the cause. Signs that anaesthesia may be too
light include:
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Patient
moves |
| :: |
Rising
pulse and blood pressure |
| :: |
Sweating,
tears. |
Anaesthesia too deep
| :: |
Falling
pulse and blood pressure |
| :: |
Depressed
breathing. |
In
addition to monitoring the cardiovascular, respiratory and
nervous systems, make regular checks of your equipment. The
commonest cause of awareness during anaesthesia is the vaporizer
running dry.
Waking the patient up
There is no antidote for anaesthesia:
| :: |
Whenever
you give a drug, you must have an idea of how long its effect
will last |
| :: |
Different
drugs wear off at different rates; be prepared to continue
to support the patient’s breathing and airway for
as long as necessary at the end of the case |
| :: |
Remove
the tracheal tube only if the patient is either deeply
anaesthetized (to avoid laryngeal spasm) or is awake. |
Give extra oxygen before and after the end of the anaesthetic. Continue to
monitor the patient just as carefully after you have turned the anaesthetic
off until he or she is fully awake.
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