Investigation of the relationship between depth of anesthesia and blink reflex obtained by electrical stimulation in dogs

The, aim of this study was to evaluate the relationship between the blink reflex and the depth of anesthesia in dogs and the effect of the blink reflex on determining the depth of anesthesia and to evaluate the parameters that can be obtained from it.The study material consisted of sixteen dogs (11 female, 5 male), body weight between 13- 30 kg (mean, 21,31 ± 1,41 kg) were brought to the Surgical Clinic of Burdur Mehmet Akif Ersoy University (MAKÜ), the Faculty of Veterinary Medicine for various operations. Propofol was used all dogs 4 mg/kg for anesthesia induction. Subsequently, anesthesia was maintained with sevoflurane. Anesthesia was kept constant at 2,9 MAC, which is the end tidal MAC value that provides deep anesthesia for dogs. Following the end of the operation, starting from 2,9 end tidal MAC, electrical stimulation was given to the supraorbital nerve for each declining 0,1 MAC valueand blink parameters were recorded from both orbicularis oculi. A significant relationship was found between the all latency, amplitude, time values and MAC excluding latency and duration of R2c parameter with differential latency. The success rates of the blink parameters related to MAC were determined. In some literature, R2c value has been accepted as a criterion for surface anesthesia. During the operation, R2c value, which was accepted as the criterion for showing superficial anesthesia during anesthesia, could not be obtained to indicate superficial anesthesia. However, once the R2c value was obtained, the stimulus given for the blink reflex at lower MAC values could not be tolerated by the patients. Therefore stimulus weren't given again. The mean end Tidal MAC value for the R2c value vas 0,88. It was thought that R2c value could not be a cri terion to Show superficial anesthesia during anesthesia.