Published ahead of print on November 8, 2002, doi:10.1164/rccm.200207-768BC Am. J. Respir. Crit. Care Med., Volume 167, Number 4, February 2003, 557-562 A more recent version of this article appeared on February 15, 2003
Submitted on July 30, 2002 Hypersensitivity of laryngeal C-fibers induced by volatile anesthetics in young guinea pigsTatsushi Mutoh1 and Hirokazu Tsubone2*1 Department of Veterinary Surgery, The University of Tokyo, Tokyo, Japan; Department of Brain Sciences, Kobe University Graduate School of Medicine, Kobe, Japan, 2 ; Department of Comparative Pathophysiology, The University of Tokyo, Tokyo, Japan * To whom correspondence should be addressed. E-mail: aahiro{at}mail.ecc.u-tokyo.ac.jp.
Inhalation induction of anesthesia with a single volatile anesthetic is commonly used in children, but is sometimes associated with increased cough, secretion, and airway obstruction, which may result in part from stimulation of laryngeal C-fibers. We examined the effects of two popular volatile anesthetics, halothane and sevoflurane, on laryngeal C-fiber responsiveness in urethane-anesthetized guinea pigs (from age 4 - 5 weeks). Following administration of halothane or sevoflurane to the functionally isolated upper airway, laryngeal C-fiber afferents recorded from the internal branch of the superior laryngeal nerve and identified by a conduction velocity of < 2.0 m/s were tested for responsiveness to chemical and mechanical stimuli. Halothane doubled C-fiber responsiveness to capsaicin injected into the left atrium or nebulized to the larynx and to laryngeal hyperinflation, compared with sevoflurane, but had no effect on baseline activity. The data indicate that, compared with sevoflurane, halothane more markedly enhances laryngeal C-fiber sensitivity to chemical and mechanical stimuli in young guinea pigs, which would explain the greater number of respiratory-related complications in children during induction of anesthesia with this agent. Key words: airway irritation; laryngeal C-fibers; volatile anesthetics
This article has been cited by other articles:
|
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
