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The acute hypoxic ventilatory response under halothane, isoflurane, and sevoflurane anaesthesia in rats *
Author(s) -
Karanovic N.,
Pecotic R.,
Valic M.,
Jeroncic A.,
Carev M.,
Karanovic S.,
Ujevic A.,
Dogas Z.
Publication year - 2010
Publication title -
anaesthesia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.839
H-Index - 117
eISSN - 1365-2044
pISSN - 0003-2409
DOI - 10.1111/j.1365-2044.2009.06194.x
Subject(s) - isoflurane , halothane , sevoflurane , medicine , hypoxic ventilatory response , anesthesia , potency , hypoxia (environmental) , phrenic nerve , minimum alveolar concentration , respiratory system , oxygen , biology , chemistry , in vitro , biochemistry , organic chemistry
Summary The relative order of potency of anaesthetic agents on the hypoxic ventilatory response has been tested in humans, but animal data are sparse. We examined the effects of 1.4, 1.6, 1.8, and 2.0 MAC halothane, isoflurane, and sevoflurane on phrenic nerve activity in euoxia (baseline) and during acute normocapnic hypoxia (inspired oxygen fraction 0.09) in adult male Sprague‐Dawley rats. With halothane, all animals became apnoeic even in euoxia, and the hypoxic response was completely abolished at all anaesthetic levels. With isoflurane, 5 of 14 animals exhibited phrenic nerve activity in euoxia at 1.4 MAC and demonstrated a hypoxic response (302% of baseline activity), but all became apnoeic and lost the hypoxic response at higher doses. With sevoflurane, phrenic nerve activity and a hypoxic response was preserved in at least some animals at all doses (i.e. even the highest dose of 2.0 MAC). Similar to the rank order of potency previously observed in humans, the relative order of potency of depression of the hypoxic ventilatory response in rats was halothane (most depressive) > isoflurane > sevoflurane (p = 0.01 for differences between agents).