Open AccessElectroencephalogram of Healthy Horses During Inhaled Anesthesia
Author(s) -
Williams D.C.,
Aleman M.R.,
Brosnan R.J.,
Fletcher D.J.,
Holliday T.A.,
Tharp B.,
Kass P.H.,
Steffey E.P.,
LeCouteur R.A.
Publication year - 2015
Publication title -
journal of veterinary internal medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.356
H-Index - 103
eISSN - 1939-1676
pISSN - 0891-6640
DOI - 10.1111/jvim.13613
Subject(s) - isoflurane , medicine , halothane , anesthesia , electroencephalography , inhalation , sedation , burst suppression , ventilation (architecture) , desflurane , mechanical engineering , psychiatry , engineering
Background Previous study of the diagnostic validity of electroencephalography ( EEG ) to detect abnormalities in equine cerebral cortical function relied on the administration of various drugs for sedation, induction, and maintenance of general anesthesia but used identical criteria to interpret recordings. Objectives To determine the effects of 2 inhalation anesthetics on the EEG of healthy horses. Animals Six healthy horses. Methods Prospective study. After the sole administration of one of either isoflurane or halothane at 1.2, 1.4, and 1.6 times the minimum alveolar concentration, EEG was recorded during controlled ventilation, spontaneous ventilation, and nerve stimulation. Results Burst suppression was observed with isoflurane, along with EEG events that resembled epileptiform discharges. Halothane results were variable between horses, with epileptiform‐like discharges and bursts of theta, alpha, and beta recorded intermittently. One horse died and 2 were euthanized as the result of anesthesia‐related complications. Conclusions and Clinical Importance The results of this study indicate that the effects of halothane and isoflurane on EEG activity in the normal horse can be quite variable, even when used in the absence of other drugs. It is recommended that equine EEG be performed without the use of these inhalation anesthetics and that general anesthesia be induced and maintained by other contemporary means.