Oral clonidine does not change ventilatory response to carbon dioxide in sevoflurane-anesthetized children.
BACKGROUND
Clonidine is a useful premedicant for pediatric anesthesia. The drug has potential for ventilatory depression. The aim of the current study was to determine the effects of clonidine premedication on the ventilatory response to hypercapnia during sevoflurane anesthesia using the carbon dioxide (CO(2)) steady state method.


METHODS
Sixty children (3-13 yr) were assigned to receive clonidine 4 microg x kg(-1) or placebo. Anesthesia was maintained with spontaneous breathing and 2% sevoflurane. Minute ventilation (VE), respiratory rate (RR), endtidal CO(2) pressure (P(ECO(2)), and arterial hemoglobin oxygen saturation (SpO2) were measured with a facemask tightly fitted before and during 7% CO(2) inhalation.


RESULTS
Compared with placebo, oral clonidine failed to reduce VE volume before CO(2) loading under general anesthesia with 2% sevoflurane. Inhalation of CO(2) increased VE. Oral clonidine did not attenuate the increase in VE induced by hypercapnic challenge under sevoflurane anesthesia. There were no differences in RR, P(ECO(2), or SpO2 between the placebo and clonidine groups before and during CO(2) loading.


CONCLUSIONS
These data suggest that oral clonidine is a suitable premedication for sevoflurane anesthesia under spontaneous breathing conditions in children.
Nishina
Kahoru
K
Department of Anesthesia and Perioperative Medicine, Faculty of Medical Sciences, Kobe University Graduate School of Medicine, Kusunoki-cho, Chuo-ku, Kobe, Japan.
Mikawa
Katsuya
K
Uesugi
Takanobu
T
Obara
Hidefumi
H
D000284:Administration, Oral; D000293:Adolescent; D000700:Analgesics / Q000008:administration & dosage*; D000704:Analysis of Variance; D018685:Anesthetics, Inhalation; D002245:Carbon Dioxide / Q000008:administration & dosage*; D002648:Child; D002675:Child, Preschool; D003000:Clonidine / Q000008:administration & dosage*; D006801:Humans; D006935:Hypercapnia / Q000139:chemically induced / Q000503:physiopathology; D008738:Methyl Ethers; D011229:Preanesthetic Medication / Q000379:methods; D012123:Pulmonary Ventilation / Q000187:drug effects*; D000077149:Sevoflurane
D000700:Analgesics; D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D002245:Carbon Dioxide; D000077149:Sevoflurane; D003000:Clonidine