Bloqueio anestésico do plexo braquial por via supraclavicular e avaliação eletrocardiográfica em Sapajus libidinosus (Spix, 1823) sob contenção química com tiletamina-zolazepam e propofol.

Abstract

Among the protocols required to aid handling and reduce animal life risks, anesthesia, in particular local anesthesia, becomes an excellent pharmacological tool. Among the techniques of local anesthesia, anesthesia of the brachial plexus is aimed at blocking a specific region of the thoracic limb for surgical procedures with a greater margin of safety, and can be performed by five routes, among which the supraclavicular route proves to be the most viable in the capuchin monkeys, according to the literature. In addition, monitoring of cardiorespiratory function during anesthesia procedures is essential. The aim of this study was to determine the electrocardiographic pattern of black striped capuchin monkeys (Sapajus libidinosus) and to evaluate the technique of brachial plexus block through the supraclavicular way of these animals. Eight animals were used for the study of plexus block and nine for the electrocardiogram study. Initially the animals were sedated with tiletamine-zolazepam intramuscularly (5 mg/kg) and the ECG was performed, which lasted approximately three minutes, in single registration. The interpretation was performed by determining the following parameters: heart rate (HR) in bpm and heart rate, P wave (ms/mV), PR interval (ms), R wave (mV), QRS complex (ms), T wave (mV), Q-T interval, corrected QT and electric axis (°). Subsequently, anesthesia was induced intravenously, with propofol bolus (0.5-1.5 mg/kg), and the animals were kept on a hypnosis plane. These patients underwent brachial plexus block with the aid of a neurolocalizer, using lidocaine 2% without vasoconstrictor (5 mg/kg). Physiological parameters, nociception by means of electrotherapy apparatus, response to electrical stimulation and cutaneous sensitivity were evaluated before brachial plexus injection and at 5, 10, 15, 20, 30, 40 and 50 minutes after. The groups were compared by the Tukey or Friedman test at 5% significance, using the statistical program Bioestat 5.0. In the electrocardiographic tracing, most of the monkeys presented normal sinus rhythm, followed by an animal with sinusal tachycardia. During the evaluation of the block, the rectal temperature presented reduction after 5 minutes and there was no significant difference among the other physiological variables. The average time of return of the spontaneous movement of the limbs exceeded 50 minutes of evaluation. No animals showed abnormal gait after the experiment. All animals presented silent anesthetic recovery, without excitation, vocalization or cataleptic movements.