Effects of thoracolumbar epidural anesthesia with lidocaine on the systemic hemodynamics and hepatic blood flow in propofol anesthetized dogs

• Published in: Journal of Veterinary Medical Science Vol. 83; no. 12; pp. 1877 - 1884
• Main Authors: ISERI, Toshie, NAKAMORI, Masaya, FUJIMOTO, Yuka
• Format: Journal Article
• Language: English
• Published: Japan JAPANESE SOCIETY OF VETERINARY SCIENCE 2021; Japan Science and Technology Agency; The Japanese Society of Veterinary Science
• Subjects: Anesthesia; Anesthesia, Epidural - veterinary; Anesthetics; Anesthetics, Local - pharmacology; Animals; Blood flow; Blood pressure; Blood vessels; Catheters; dog; Dogs; Epidural; epidural anesthesia; Heart rate; Hemodynamics; Hepatic artery; hepatic blood flow; Inhalation; Intravenous administration; Lidocaine; Lidocaine - pharmacology; Liver; local analgesia; Local anesthetics; Propofol; Propofol - pharmacology; Surgery; Sympathetic ganglia; Sympathetic nerves; Vasodilation; hepatic blood flow; epidural anesthesia; local analgesia; dog; lidocaine
• ISSN: 0916-7250; 1347-7439
• DOI: 10.1292/jvms.20-0611

General anesthesia reduces hepatic blood flow (HBF) from circulatory depression. Total intravenous anesthesia (TIVA) is associated with decreased circulatory depression compared to inhalation anesthesia, and epidural anesthesia using local anesthetics increases blood flow by blocking the sympathetic nerves and expanding blood vessels. We investigated the effects of thoracolumbar epidural anesthesia with TIVA on HBF in dogs. Six Beagle dogs had epidural catheters placed between T13 and L1 and were anesthetized with propofol and vecuronium. Physiological saline (control) or 2% lidocaine (0.2 ml/kg, followed by 0.2 ml/kg/hr) was administered at 1–2 weeks intervals. Heart rate (HR), cardiac index (CI), mean arterial pressure (MAP), and systemic vascular resistance index (SVRI) were recorded at 10-min intervals from before epidural injections (T0) to 110 min. Indocyanine green test was used to measure HBF during the awake state and until 90 min after epidural injections. HR and CI did not differ between treatments. MAP and SVRI after lidocaine were significantly lower than those of controls, and the lowest MAP value was 65 ± 11 mmHg at T10. Compared to T0, after lidocaine treatment, HBF was significantly higher at T30, T60 and T90 (P<0.05); while, after control treatment, no significant change was evident at any time point. Despite a decrease in MAP by this technique, HBF was either maintained at pre-anesthetic levels or increased in comparison to controls, probably due to vasodilation of the hepatic artery induced by the selective blockade sympathetic ganglia.