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TOTAL INTRAVENOUS ANAESTHESIA
In some countries, increasing use is being made of total intravenous
anaesthesia (TIVA) in which all anaesthetic drugs, including
drugs such as relaxants and analgesics, are given by intravenous
infusion at a rate precisely controlled by an electronic syringe
pump that effectively eliminates the need for a vaporizer.
At present, the drugs most suitable for such techniques – such
as propofol, midazolam and ketamine – may be too expensive
for widespread use. It is not possible to substitute cheaper
drugs such as thiopental, as they accumulate to very high levels
during continuous infusion. If a suitable range of short-acting
drugs becomes available at reasonable prices, TIVA may become
more widely accepted and used at the district hospital level.
The following technique, using TIVA with ketamine, is however
suitable, economical and widely used.
TIVA with ketamine
| 1 |
After
premedication with atropine and pre-oxygenation, induce
anaesthesia with a fast-running ketamine infusion containing
1 mg/ml (average adult dose 50–100 ml). |
| 2 |
Give
suxamethonium and intubate the trachea. |
| 3 |
Maintain
anaesthesia with ketamine 1–2 mg/minute (more
if the patient has not received premedication). After
breathing returns, give a nondepolarizing relaxant. |
| 4 |
Ventilate
with air, enriched with oxygen if available. |
| 5 |
At
the end of surgery, reverse the muscle relaxation and
extubate with the patient awake, as after inhalational
anaesthesia. |
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