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Effect of halothane on the cerebral circulation in young children: a hysteresis phenomenon
Author(s) -
Paut O.,
Bissonnette B.
Publication year - 2001
Publication title -
anaesthesia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.839
H-Index - 117
eISSN - 1365-2044
pISSN - 0003-2409
DOI - 10.1046/j.1365-2044.2001.01708-4.x
Subject(s) - halothane , medicine , nitrous oxide , anesthesia , cerebral blood flow , oxygen , cerebral circulation , blood pressure , carbon dioxide , ecology , chemistry , organic chemistry , biology
To determine the effect of halothane on the cerebral blood flow velocity (CBFV) with increasing then decreasing concentrations, 11 children scheduled for minor surgery were studied. Anaesthesia consisted of halothane, vecuronium, nitrous oxide in oxygen and a caudal block. End‐tidal carbon dioxide, temperature, heart rate and systolic arterial pressure were maintained constant. CBFV increased significantly between 0.5 and 1.0 MAC (p <0.001), and 0.5 and 1.5 MAC of halothane (p <0.001), but was not different after increasing concentration from 1.0 to 1.5 MAC. During the decreasing phase, CBFV decreased significantly from 1.5 to 1.0 MAC of halothane (p <0.001), whereas there was no difference in CBFV when decreasing halothane MAC from 1.0 to 0.5 MAC. In children, the decrease in CBFV during decreasing halothane concentration is not superimposable to the increase in CBFV seen when increasing halothane concentration, suggesting the presence of cerebrovascular hysteresis to halothane.