Bispectral index in calves anesthetized with xylazine, midazolam, ketamine, isoflurane and subjected to continuous rate infusion of lidocaine

Abstract

PURPOSE:To assess the bispectral index (BIS) and recovery in calves anesthetized with xylazine, midazolam, ketamine and isoflurane and subjected to CRI of lidocaine. METHODS:Xilazine was administered followed by ketamine and midazolam, orotracheal intubation and maintenance on isoflurane using mechanical ventilation. Lidocaine (2 mg kg -1 bolus) or saline (0.9%) was administered IV followed by a CRI (100 µg kgof lidocaine (L) or saline (C). Were recorded BIS, heart rate (HR), mean arterial pressure (MAP) and rectal temperature (RT) before administration of premedication (TB) and 15 minutes after (TX), before administering lidocaine (T0) and 20, 40, 60 and 80 minutes after the start of the CRI . Time do sternal recumbency (SRE) and standing (ST) and plasma lidocaine concentration also evaluated. RESULTS:In both treatments BIS decreased significantly at all times compared to TB. TX was higher than the subsequent times. HR decreased from baseline at all times and decreased from T40 in L compared to C. SRE was higher in L compared to C. CONCLUSIONS:Bispectral index values were consistent with the degree of hypnosis of the animals. Lidocaine did not potentiate isoflurane anesthesia assessed by BIS in unstimulated calves anesthetized with constant E´Iso. Lidocaine increased the time to sternal recumbency.

Continuous infusion of propofol in calves: bispectral index and hemodynamic effects

“…A potentially important point in relation to BIS is that the values of 50 in this study and 37 in another study (Ara ujo et al 2015) are lower than BIS values reported in dogs (Ferro 2003;Lopes et al 2008a), which could suggest that the value of BIS in calves that represents a hypnotic level comparable with surgical anesthesia may be lower than in other species.…”

“…In contrast, BIS values recorded in this and another study (Ara ujo et al 2015) may not be reliable indicators of anesthetic depth in the bovine species, as the BIS monitor was developed for use in humans and the values may not extrapolate to other species. The literature regarding BIS in cattle is scarce and we were unable to find reference values.…”

“…Shortly after induction of anesthesia and initiation of propofol infusion, the BIS decreased to approximately 50 and was not different between the treatments. Similarly, no difference in BIS was measured in calves anesthetized with isoflurane and either a continuous infusion of lidocaine or of saline (Ara ujo et al 2015). However, the mean BIS score of 37 in that study was lower than in the present study, most probably the result of the use of different anesthetics Table 2 The mean AE SD of BIS, SQI and EMG variables obtained from eight calves before anesthesia (baseline) and during 60 minutes of continuous propofol infusion: 0.6 mg kg À1 minute À1 (treatment G6) and 0.8 mg kg À1 minute À1 (treatment G8) that increased cerebral depression and decreased BIS scores.…”

“…Similarly, no difference in BIS was measured in calves anesthetized with isoflurane and either a continuous infusion of lidocaine or of saline (Araújo et al. ). However, the mean BIS score of 37 in that study was lower than in the present study, most probably the result of the use of different anesthetics that increased cerebral depression and decreased BIS scores.…”

Effect of ketamine combined with lidocaine in pediatric anesthesia

“…In our study, the findings exhibited the combination of ketamine and lidocaine to be more effective and safer for pediatric anesthesia, which was evidenced by more stable vital signs (reduced SBP, HR, and RR) of pediatric patients in response to the combination treatment with ketamine and lidocaine than ketamine treatment alone. It has been suggested that IV lidocaine could potentiate changes in HR by interacting with sodium channels and repressing cellular calcium influx, thus inducing changes in depolarization and conduction velocity in myocardial Purkinje fibers . SBP change may be observed on an arterial pressure waveform induced by changes in intrathoracic pressure resulting from controlled ventilation .…”