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June
1998
Sevoflurane
compared with halothane for tracheal intubation in children.
O'Brien
K, Kimar R, Morton NS. Br J Anaesth 1998;80:452-55.
[ see
abstract below ]
O'Brien et al studied 40 infants undergoing tracheal intubation following
administration of either halothane or sevoflurane. The clinical endpoint
used to begin laryngoscopy was small pupils with central pupil position.
Nineteen of 20 patients in each group were judged to have acceptable intubating
conditions, although the vocal cords were more likely to be moving or
closing with sevoflurane than with halothane. In addition, the time to
reach conditions for intubation was more rapid with halothane.
It should be noted that 60% nitrous oxide was used, and the authors suggest
that further study might be warranted using 100% oxygen rather than the
inhalation agent used in this study: nitrous oxide and oxygen. The finding
that intubation conditions were reached sooner with halothane than with
sevoflurane might seem surprising on the surface. However, 8% sevoflurane
may only be 3-3.5 MAC whereas 5% halothane may be 5-7 MAC. Over-pressurization
may result in a more rapid deepening with halothane. It would have been
interesting to compare equi-MAC concentrations.
One of the greatest concerns for those of us who anesthetize infants on
a regular basis is the potential for cardiovascular depression/electromechanical
dissociation. Some have argued that sevoflurane may have less potential
for this effect than halothane because of sevoflurane's better cardiovascular
depression profile. In fact, it may more likely relate to the fact that
many more MAC multiples can be administered for halothane than for sevoflurane.
The caveat I would like to stress is the importance of having an intravenous
line in place before deepening of anesthesia, and the administration of
atropine to oppose the cardiovascular depression of the inhalation agents.
Return to the Current
Literature Review Front Page , or read the abstract:
ABSTRACT
We have studied 40 healthy children, aged 3-10 yr, undergoing adenotonsillectomy,
in a double-blind, randomized study.
Intubating conditions were assessed when the pupils had become small and
central after inhalation induction with either 5% halothane and 60% nitrous
oxide in oxygen or 8% sevoflurane and 60% nitrous oxide in oxygen. The quality
of tracheal intubation was graded according to ease of laryngoscopy, position
of the vocal cords, coughing, jaw relaxation and movement of the limbs.
Fewer children had significant vocal cord movement on laryngoscopy (P <0.01)
and more had ideal intubating conditions when halothane was used (12 of
20 compared with 7 of 20; ns). Time to reach the clinical end-point for
intubation was reached sooner with halothane (P=0.015). In all children
the trachea was intubated successfully at the first attempt and all remained
haemodynamically stable throughout induction.
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