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Strauss JM, Giest J.
Klinik fur Anasthesiologie und Operative
Intensivmedizin, HELIOS Klinikum Berlin, Germany.
Vol 1, N. 5, Dicembre 2003
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Since
venous cannulation in children has become easier and extensive experience
has been gained with total intravenous anaesthesia (TIVA) in adults, the
interest in TIVA for children has recently increased. An intensified sensitivity
of the operating room atmosphere to contamination with volatile anaesthetic
agents is another important reason to choose intravenous techniques for
paediatric anaesthesia. One of the most interesting agents for TIVA in
paediatric anaesthesia is propofol. The pharmacokinetic and pharmacodynamic
data for modern intravenous drugs is poor. Because the interpatient variability
is relatively large, pharmacokinetic data can only provide guidelines
for the dosage of propofol. Propofol has a rapid and smooth onset of action
and is as easy to titrate in children as in adults. Propofol can be excellently
controlled. Severe haemodynamic side-effects are missing in healthy children
and plasma is cleared rapidly of propofol by redistribution and metabolism.
There is no evidence of significant accumulation, not even after prolonged
infusion times. Because propofol has no analgetic properties it must be
combined with analgetics or a regional block for all painful procedures.
The combination with the ultra-short acting remifentanil is a major advantage,
but requires effective analgetic concepts for painful procedures. In comparison
the combination of propofol with long acting opioids abolishes some of
the favourable properties of propofol. Further studies of the kinetics
and dynamics of propofol and other intravenous agents are needed in paediatrics
which should focus on age, maturity and severity of illness. The whole
importance of the propofol-infusion syndrome has to be cleared up urgently.
TIVA has an important significance in paediatric anaesthesia for diagnostic
and therapeutic procedures, especially where these have to be repeated.
In day-case anaesthesia TIVA has advantages for all short procedures and
for ENT and ophthalmic surgery: even after prolonged infusion children
have an short recovery time. There is no evidence of agitation or other
behavioural disorders after TIVA with propofol in paediatric anaesthesia.
Propofol has anti-emetic properties. TIVA with propofol can be combined
with regional anaesthesia advantageously to provide long-lasting analgesia
after surgery. TIVA with propofol has been used successfully for sedation
of spontaneously breathing children for MRI and CT and other procedures
with open airways like bronchoscopy or endoscopy. Propofol facilitates
endotracheal intubation without the use of muscle relaxants. Of course,
in malignant hyperthermia TIVA will continue to be the technique of choice.
Nothing is known about awareness under TIVA in paediatric patients. TIVA
must be considered by comparison with the volatile agents. The use of
ultra-short acting agents may cause problems such as awareness, vagal
response, involuntary movements and in some cases slow recovery after
prolonged infusion of propofol. But it is not known exactly how often
this happens during paediatric anaesthesia. With TIVA an effective postoperative
analgesia must be provided. Newer administration techniques such as the
target-controlled infusions or closed-loop control systems are under development
and will help to minimise the potential risk of overdosage with TIVA in
paediatrics. At the present TIVA is an interesting and practicable alternative
to volatile anaesthesia for pre-school and school children. TIVA with
propofol in infants younger than 1 year old requires extensive experience
with TIVA in older children and with the handling of this special age
group and should be undertaken with maximum precautionary measures.
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