212 Bulletin UASVM, Veterinary Medicine 65(2)/2008 pISSN 1843-5270; eISSN 1843-5378 PROPOFOL-THIOPENTAL MIXTURE IN BRACHYCEPHALIC DOGS PREPARED FOR MYELOGRAPHY Schuszler Larisa, C. Igna, A. Sala Faculty of Veterinary Medicine Timioara, Calea Aradului no. 119, 300645 Timioara, Romania, larisaschuszler@yahoo.com Keywords: propofol-thiopental mixture, brachycephalic, myelography Abstract: The purpose of the present study was to evaluate the safety of use the propofol-thiopental mixture in brachycephalic dogs and the recovery quality when it is used for perform an ancillary diagnostic test of spinal condition, myelography. Nine brachycephalic dogs were anesthetized by bolus IV administration of 0,5 ml/kg propofol 1%-thiopental 2,5% 1:1 mixture, followed by repeated supplementations of 20% of the initial dose every 10 seconds until endotracheal intubation was possible and an adequate plane of anesthesia that permitted performing myelography procedure in safe condition was achieved. Pulse quality, capillary refill time, mucous membrane color, respiratory rate, oxygenation, the length of anesthetic effect, the quality of recovery and total volume of anesthetic administered were recorded. INTRODUCTION Brachycephalic dog breeds at both induction and recovery periods may have difficulty maintaining a patent airway, often hypoventilate during anesthesia and more frequently vomit during recovery. Anesthesia may be maintained, especially for short time periods, exclusively with injectable drugs. Myelography is carried out with the dog under general injectable anesthesia, if this is to be avoided then the procedure may not be possible because it is imperative that the animal not move during this time (12, 26). Myelograms can cause significant complications, like excitement phenomena, convulsions in the postanesthetic recovery period and raise of cerebrospinal fluid pressure (1, 20). Because of high incidence of seizures various anesthetic techniques have been recorded in the past, the most common use anticonvulsant drugs as preanesthetic medication delays the awakening from anesthesia (12). On the other hand, in some patients sedatives in usual doses may result in marked depression so that respiration is compromised. This is most commonly seen in older animals, brachycephalic breeds, and in those with pre-existing respiratory or cardiac disease (10). We are dealt with two major problems: specific breed respiratory problems and possible complications associated with diagnostic procedure. These are reasons for choosing an anesthesia alternative with minimal impact on respiratory function, with possibility to secure airway, with rapid recovery that allows complete restoring of respiratory function, with anticonvulsivant properties and which decrease the cerebrospinal fluid pressure. For many species propofol is associated with smooth and rapid onset of action with easy titration to the desired anesthetic plane, short duration of activity, lack of cumulative effect and rapid recovery without unwanted excitatory effects (6, 7, 14, 19). Propofol has been found to have anticonvulsivant activity, and demonstrated effects of reducing cerebrospinal fluid pressure (5, 11). The principal disadvantage of propofol is that causes substantial respiratory depression and apnea (15, 23, 27). A greater degree of respiratory depression of a longer duration is seen with propofol than with thiopental (23).