TY - JOUR
T1 - Respiratory reflexes in response to upper-airway administration of sevoflurane and isoflurane in anesthetized, spontaneously breathing dogs
AU - Mutoh, Tatsushi
AU - Kanamaru, Arata
AU - Tsubone, Hirokazu
AU - Nishimura, Ryohei
AU - Sasaki, Nobuo
N1 - Funding Information:
From the Laboratories of Veterinary Surgery and Comparative Pathophysiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan. Supported by a Research Fellowship of the Japan Society for the Promotion of Science for Young Scientists. Address reprint requests to T. Mutoh, DVM, PhD, Laboratory of Veterinary Surgery, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan. © Copyright 2001 by The American College of Veterinary Surgeons 0161-3499/01/3001-0010$35.00/0 doi:10.1053/jvet.2001.20329
PY - 2001/1
Y1 - 2001/1
N2 - Objective - To evaluate the respiratory effects occurring during administration of sevoflurane or isoflurane to the upper airway in dogs. Study Design - A prospective, randomized study. Animals - Twelve healthy adult beagles (6 males, 6 females). Methods - At least 2 weeks after undergoing permanent tracheostomy, dogs were premedicated with acepromazine-buprenorphine, and anesthesia was induced with thiopental and maintained with a-chloralose. The upper airway was functionally isolated so that the inhalant could be administered to the upper airway while dogs were breathing 100% O2 via the tracheostomy. Respiratory reflexes in response to the administration of sevoflurane or isoflurane at concentrations of 1.2, 1.8, and 2.4 times the minimal alveolar concentration (MAC) (administered in 100% O2 at a flow rate of 5 L/min) were recorded. Reflexes in response to administration of each anesthetic were also recorded following upper-airway administration of lidocaine. Results - Respiratory reflexes elicited by upper-airway administration of each anesthetic were characterized by a dose-dependent increase in expiration time, with a resultant decrease in respiratory minute ventilation and increase in end-tidal PCO2. The magnitude of these responses was greater with isoflurane than with sevoflurane at 1.8 and 2.4 MAC. These reflexes were abolished after lidocaine nebulization into the upper airway. Conclusion - Isoflurane induces greater reflex inhibition of breathing than does sevoflurane when the anesthetic is inhaled into the upper airway at concentrations used for mask induction.
AB - Objective - To evaluate the respiratory effects occurring during administration of sevoflurane or isoflurane to the upper airway in dogs. Study Design - A prospective, randomized study. Animals - Twelve healthy adult beagles (6 males, 6 females). Methods - At least 2 weeks after undergoing permanent tracheostomy, dogs were premedicated with acepromazine-buprenorphine, and anesthesia was induced with thiopental and maintained with a-chloralose. The upper airway was functionally isolated so that the inhalant could be administered to the upper airway while dogs were breathing 100% O2 via the tracheostomy. Respiratory reflexes in response to the administration of sevoflurane or isoflurane at concentrations of 1.2, 1.8, and 2.4 times the minimal alveolar concentration (MAC) (administered in 100% O2 at a flow rate of 5 L/min) were recorded. Reflexes in response to administration of each anesthetic were also recorded following upper-airway administration of lidocaine. Results - Respiratory reflexes elicited by upper-airway administration of each anesthetic were characterized by a dose-dependent increase in expiration time, with a resultant decrease in respiratory minute ventilation and increase in end-tidal PCO2. The magnitude of these responses was greater with isoflurane than with sevoflurane at 1.8 and 2.4 MAC. These reflexes were abolished after lidocaine nebulization into the upper airway. Conclusion - Isoflurane induces greater reflex inhibition of breathing than does sevoflurane when the anesthetic is inhaled into the upper airway at concentrations used for mask induction.
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U2 - 10.1053/jvet.2001.20329
DO - 10.1053/jvet.2001.20329
M3 - Article
C2 - 11172464
AN - SCOPUS:0035227247
VL - 30
SP - 87
EP - 96
JO - Veterinary Surgery
JF - Veterinary Surgery
SN - 0161-3499
IS - 1
ER -