Alterações eletrocardiográficas em cães pré-medicados com levomepromazina e submetidos à anestesia por propofol e sevoflurano

Abstract

The electrocardiographic changes were evaluated in 16 clinically healthy adult dogs, males and females, under sevoflurane anesthesia, with a mean body weight of 15±3.5kg. Levomepromazine (1.0 mg/kg) was administered intravenously, followed by induction with propofol (5.0 mg/kg). Dogs were then intubated and sevoflurane diluted in oxygen was administered using a semi-closed circuit, at a final concentration of 3.5V%. Heart and respiratory rates, pulse oximetry, capnometry, systolic, diastolic and mean arterial pressures and electrocardiographic variables were determined immediately before levomepromazine administration, 15 minutes later and immediately before induction with propofol, 15 minutes after administration of sevoflurane and thereafter every 20 minutes. After levomepromazine and sevoflurane administration there was a decrease in both systolic and mean arterial pressures. Levomepromazine caused a QT interval prolongation. Sevoflurane caused prolongation and increase in amplitude of the P wave at 70 and 130 minutes, respectively, as well as a prolongation of the QT internal. It is concluded that sevoflurane anesthesia, as done herein, caused a prolonged QT interval, with no detectable arrhythmias.