Korean J Anesthesiol.  2010 Jun;58(6):527-531. 10.4097/kjae.2010.58.6.527.

Caudal analgesia reduces the sevoflurane requirement for LMA removal in anesthetized children

• Kim JS
• Park WK
• Lee MH
• Hwang KH
• Kim HS
• Lee JR

• KMID: 2031693
• DOI: http://doi.org/10.4097/kjae.2010.58.6.527

Abstract

BACKGROUND
An anesthetic state can reduce adverse airway reaction during laryngeal mask airway (LMA) removal in children. However, the anesthetic state has risks of upper airway obstruction or delayed emergence; so possibly less anesthetic depth is advisable. Caudal analgesia reduces the requirement of anesthetic agents for sedation or anesthesia; it is expected to reduce the sevoflurane requirement for LMA removal. Therefore, we determined the EC(50) of sevoflurane for LMA removal with caudal analgesia and compared that to the EC(50) without caudal analgesia.
METHODS
Forty-three unpremedicated children aged 1 to 6 yr were enrolled. They were allocated to receive or not to receive caudal block according to their parents' consent. General anesthesia were induced and maintained with sevoflurane and oxygen in air. EC(50) of sevoflurane for a smooth LMA removal with and without caudal analgesia were estimated by the Dixon up-and-down method. The LMA was removed when predetermined end-tidal sevoflurane concentration was achieved, and the sevoflurane concentration of a subsequent patient was determined by the success or failure of the previous patient with 0.2% as the step size; success was defined by the absence of an adverse airway reaction during and after LMA removal. EC(50) of sevoflurane with caudal block, and that without caudal block, were compared by a rank-sum test.
RESULTS
The EC(50) of sevoflurane to achieve successful LMA removal in children with caudal block was 1.47%; 1.81% without caudal block. The EC(50) were significantly different between the two groups (P < 0.001).
CONCLUSIONS
Caudal analgesia significantly reduced the sevoflurane concentration for a smooth LMA removal in anesthetized children.

Keyword

Caudal analgesia; Laryngeal mask airway; Sevoflurane

MeSH Terms

Aged
Airway Obstruction
Analgesia
Anesthesia, General
Anesthetics
Child
Humans
Laryngeal Masks
Methyl Ethers
Oxygen
Anesthetics
Methyl Ethers
Oxygen