Related Experiment Videos
[Bispectral index (BIS) in infants anesthetized with sevoflurane in nitrous oxide and oxygen]
Yoshitaka Kawaraguchi1, Kazuo Fukumitsu, Keiko Kinouchi
1Department of Anesthesiology, Osaka Medical Center, Research Institute for Maternal and Child Health, Izumi 594-1101.
Insights
The bispectral index (BIS) monitor shows age-dependent differences in infants. BIS values require cautious interpretation in infants under six months for monitoring hypnosis during anesthesia.
Area of Science:
- Anesthesiology
- Pediatric Anesthesia
- Neurophysiology Monitoring
Background:
- The bispectral index (BIS) is established for monitoring hypnosis in adults.
- Previous studies on BIS in pediatric patients exist, but its utility in infants remains uncertain.
- This study investigates the applicability of BIS monitoring in infants.
Purpose of the Study:
- To evaluate the bispectral index (BIS) monitor's effectiveness in assessing the depth of hypnosis in infants.
- To determine if BIS values differ significantly between age groups of infants.
- To assess the impact of premedication on BIS values in infants.
Main Methods:
- Forty-three infants were divided into two age groups: 3-6 months (n=31) and 7-12 months (n=12).
- The younger group (3-6 months) was further divided into those who received midazolam premedication (n=19) and those who did not (n=12).
- BIS values were recorded at steady-state end-tidal sevoflurane concentrations (1.5%, 2%, 2.5%) and before extubation.
Main Results:
- BIS values were significantly lower in the 3-6 month age group compared to the 7-12 month group at all sevoflurane concentrations and before extubation (P < 0.05).
- Premedication with midazolam did not significantly affect BIS values in infants aged 6 months or younger.
- A notable difference in BIS values was observed between infants aged 6 months and younger versus those aged 7-12 months.
Conclusions:
- Significant differences in BIS values exist between infants aged 6 months and younger, and those aged 7-12 months.
- BIS values should be interpreted with caution in infants younger than six months.
- Age is a critical factor in the interpretation of BIS values for hypnosis monitoring in infants.
Background:
The bispectral index (BIS) has been shown to be useful in monitoring a degree of hypnosis in anesthetized adults. Although several studies have been performed to evaluate BIS in pediatric patients, it is unclear whether BIS monitor can be applied to infants. This study was designed to evaluate if the BIS monitor can be used in infants as a measure to monitor a degree of hypnosis.
Methods:
Forty-three infants were divided into two age groups according to their age: group A (3-6 months; n = 31) and B (7-12 months; n = 12). And the patients in the younger group were randomly allocated to one of two groups, A (+) (premedicated with oral midazolam 0.5 mg.kg-1; n = 19) and A (-) (without premedication; n = 12). BIS values and other parameters were recorded at a steady state of end-tidal sevoflurane concentration (2.5, 2, and 1.5%) and immediately before extubation.
Results:
At each concentration of sevoflurane and extubation, the BIS values were lower in group A (+) than in group B (P < 0.05). In infants < or = 6 months of age, premedication did not affect the BIS values.
Conclusion:
There were significant differences of BIS values between < or = 6 months and > or = 7 months old infants. BIS values should be interpreted cautiously in infants younger than 6 months.