Effects of Intravenous Lidocaine on Isoflurane Concentration, Physiological Parameters, Metabolic Parameters and Stress‐related Hormones in Horses Undergoing Surgery

Abstract

Physiological parameters, metabolic parameters and stress-related hormones are evaluated in horses anaesthetized with isoflurane in oxygen combined with lidocaine intravenously. Two groups of horses anaesthetized with isoflurane (six horses in each group) were studied: a lidocaine group (IL), which received intravenous lidocaine and a control group (C), which received intravenous saline. Horses in both groups were premedicated with detomidine (i.v.), and anaesthesia was induced with midazolam-ketamine (i.v.). The lidocaine group received intravenous lidocaine as a loading dose of 2.5 mg kg(-1) at 15 min after induction of anaesthesia directly followed by a maintenance dosage of 50 microg kg(-1) min(-1), while the control group received saline (i.v.) following the same regime. End-tidal isoflurane and standard physiological parameters were measured. Blood was sampled for measurement of lidocaine, stress hormones and metabolic parameters. The end-tidal isoflurane concentration in the lidocaine group was 0.96 +/- 0.06% versus 1.28 +/- 0.06% (mean +/- SD) in the control group, a significant (P < 0.05) reduction of 25%. No significant differences were found regarding stress-related hormones, metabolic and physiological parameters. This study suggests that the use of lidocaine to decrease the concentration of isoflurane to obtain a sufficient surgical anaesthesia has no subsequent effects on physiological and metabolic parameters or stress-related hormones.

Continuous intravenous lidocaine infusion during isoflurane anaesthesia in horses undergoing surgical procedures

“…In the present study, lidocaine CRI allowed for reduction to 1.2Vol%. This result correlates with MAC reduction of volatile agents in the studies of Doherty and Frazier (1998) for 20% of halothane use under experimental condition, and 25% of isoflurane use by Dzikiti et al (2003) in a clinical setting where 2.5 mg kg -1 followed by 3 mg kg-1 h-1 of lidocaine was administered. When ketamine and lidocaine infusions are added to isoflurane anaesthesia, the isoflurane requirement can be further reduced down to 1.0% (Enderle et al 2008).…”

“…In dogs, IV lidocaine infusion significantly reduced anaesthetic requirement (Matsubara et al 2009, Muir et al 2003, Steagall et al 2006, Wilson et al 2008. Driessen (2005) reviewed early the potential of IV lidocaine CRI for equine PIVA and presented some personal experience with a reduced infusion rate (1.8 mg kg -1 h -1 ) compared to previous publications (Doherty und Frazier 1998, Dzikiti et al 2003) that used 3 to 6 mg kg -1 h -1 . Further investigations confirmed the ability of systemic administration of lidocaine to decrease dose-dependently anaesthetic requirements during general anaesthesia in horses , Valverde et al 2010) without intra-anaesthetic physiological or metabolic adverse effects (Valverde et al 2010, but with the risk at the recommended dosage (3 mg kg -1 h -1 ) to develop high plasma levels under general anaesthesia (Feary et al 2005) and poor quality of the recovery phase , Valverde et al 2010).…”

“…Further investigations confirmed the ability of systemic administration of lidocaine to decrease dose-dependently anaesthetic requirements during general anaesthesia in horses , Valverde et al 2010) without intra-anaesthetic physiological or metabolic adverse effects (Valverde et al 2010, but with the risk at the recommended dosage (3 mg kg -1 h -1 ) to develop high plasma levels under general anaesthesia (Feary et al 2005) and poor quality of the recovery phase , Valverde et al 2010). To our knowledge at the moment this study was performed, there were only two trials performed to compare the administration of lidocaine to a control group in a clinical setting (Dzikiti et al 2003, but using high dose of lidocaine and with different recovery methods.…”

Effects of midazolam on isoflurane minimum alveolar concentration in goats

“…The reduction in isoflurane requirements for maintaining general anaesthesia is important as use of less isoflurane will obtund isoflurane-related adverse effects (Hikasa et al, 2002;Dzikiti et al, 2003). The common adverse effects associated with isoflurane include respiratory depression, hypotension and reduced cardiac output (Antognini and Eisele, 1993;Hikasa et al, 2002).…”

Repeatability and Reliability of Heart Rate Variability in Healthy, Adult Pony Mares

“…Stress in humans and animals can be assessed by invasive methods which include collection of blood samples for measurement of stress-related hormones, metabolic and physiological parameters [1][2][3] and arterial catheterization for direct measurement of blood pressure [2]. The disadvantage of using invasive methods is that they can influence the stress the individual is experiencing, thus not providing an accurate estimate of the actual stress experienced.…”