TY - JOUR
T1 - Cerebrovascular carbon dioxide reactivity during general anesthesia
T2 - A comparison between sevoflurane and isoflurane
AU - Nishiyama, Tomoki
AU - Matsukawa, Takashi
AU - Yokoyama, Takeshi
AU - Hanaoka, Kazuo
PY - 1999/12
Y1 - 1999/12
N2 - We compared cerebrovascular carbon dioxide reactivity during the administration of sevoflurane and isoflurane anesthesia by measuring cerebral blood flow velocity (CBFV) as an indirect measurement of cerebral blood flow. Thirty patients, 20-70 yr old, undergoing lower abdominal surgery and without known cerebral or cardiovascular system disease, were randomly assigned to either sevoflurane or isoflurane treatment groups. Anesthesia was induced with thiopental 5 mg/kg IV and maintained with either sevoflurane or isoflurane in 67% nitrous oxide and oxygen. The CBFV and pulsatility index (PI) of the left middle cerebral artery were monitored with transcranial Doppler. The PETCO2 was increased stepwise from 20 to 50 mm Hg by changing the respiratory rate with a constant tidal volume. At every 5-mm Hg stepwise change in PETCO2, CBFV and PI were recorded. CBFV increased with increasing PETCO2. CBFV was significantly smaller in the isoflurane group at PETCO2 = 20-40 mm Hg than in the sevoflurane group. The rate of change of CBFV with changes in CO2 was larger in the isoflurane group than in the sevoflurane group. PI was constant over time and was not different between groups. In conclusion, hypocapnia-induced reduction of intracranial pressure might be more effective during the administration of isoflurane than sevoflurane. Implications: Changes in cerebral blood flow caused by the changes of carbon dioxide tension are greater during the administration of isoflurane anesthesia compared with sevoflurane anesthesia. Attempts to decrease intracranial pressure by decreasing carbon dioxide tension may be more successful during isoflurane than sevoflurane anesthesia administration.
AB - We compared cerebrovascular carbon dioxide reactivity during the administration of sevoflurane and isoflurane anesthesia by measuring cerebral blood flow velocity (CBFV) as an indirect measurement of cerebral blood flow. Thirty patients, 20-70 yr old, undergoing lower abdominal surgery and without known cerebral or cardiovascular system disease, were randomly assigned to either sevoflurane or isoflurane treatment groups. Anesthesia was induced with thiopental 5 mg/kg IV and maintained with either sevoflurane or isoflurane in 67% nitrous oxide and oxygen. The CBFV and pulsatility index (PI) of the left middle cerebral artery were monitored with transcranial Doppler. The PETCO2 was increased stepwise from 20 to 50 mm Hg by changing the respiratory rate with a constant tidal volume. At every 5-mm Hg stepwise change in PETCO2, CBFV and PI were recorded. CBFV increased with increasing PETCO2. CBFV was significantly smaller in the isoflurane group at PETCO2 = 20-40 mm Hg than in the sevoflurane group. The rate of change of CBFV with changes in CO2 was larger in the isoflurane group than in the sevoflurane group. PI was constant over time and was not different between groups. In conclusion, hypocapnia-induced reduction of intracranial pressure might be more effective during the administration of isoflurane than sevoflurane. Implications: Changes in cerebral blood flow caused by the changes of carbon dioxide tension are greater during the administration of isoflurane anesthesia compared with sevoflurane anesthesia. Attempts to decrease intracranial pressure by decreasing carbon dioxide tension may be more successful during isoflurane than sevoflurane anesthesia administration.
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U2 - 10.1097/00000539-199912000-00021
DO - 10.1097/00000539-199912000-00021
M3 - Article
C2 - 10589623
AN - SCOPUS:0032702219
VL - 89
SP - 1437
EP - 1441
JO - Anesthesia and Analgesia
JF - Anesthesia and Analgesia
SN - 0003-2999
IS - 6
ER -