HEMODYNAMIC EFFECTS OF INTRAVENOUS LIDOCAINE IN DOMESTIC CATS UNDER TOTAL INTRAVENOUS ANESTHESIA

Resumen

Intravenous lidocaine administration in cats is limited by concerns regarding systemic toxicity and cardiovascular depression. This study aimed to evaluate the hemodynamic and echocardiographic effects of two intravenous lidocaine bolus administration rates in healthy cats undergoing total intravenous anesthesia. Ten cats were premedicated with gabapentin, acepromazine, and butorphanol, induced with ketamine and propofol, and maintained under anesthesia with propofol and dexmedetomidine. Cats were randomly allocated to two groups (n = 5 per group) and received lidocaine (2 mg/kg IV) over two (group A) or five minutes (group B), followed by a continuous infusion at 3 mg/kg/h. Hemodynamic and echocardiographic variables were assessed during propofol infusion (MP), after dexmedetomidine administration (MD), and at 5, 30, and 60 minutes after lidocaine administration (ML5, ML30, and ML60). Stroke volume, cardiac output, cardiac index, mean arterial pressure, and stroke distance did not change significantly. In group A, left ventricular internal diameter at end-systole increased significantly, whereas fractional shortening decreased significantly between MD and ML30. Ejection fraction and heart rate varied throughout anesthesia, without significant differences between MD and subsequent lidocaine assessment periods. Intravenous lidocaine was not associated with clinically relevant impairment of global hemodynamic performance; however, echocardiographic findings should be interpreted considering the combined cardiovascular effects of anesthetic agents and ventricular loading conditions.