Changes in the EEG during castration in horses and ponies anaesthetized with halothane

Murrell, Joanna C; Johnson, Craig B.; White, Kate; Taylor, Polly; Haberham, Zainal L; Waterman-Pearson, AE

doi:10.1046/j.1467-2995.2003.00138.x

Cited by 90 publications

(119 citation statements)

References 42 publications

(76 reference statements)

Supporting

Mentioning

108

Contrasting

Unclassified

Order By: Relevance

“…Because there were no other recognized differences in anesthetic protocol, induction score, or recovery score among the treatment groups in our study, it is possible that prolonged recumbency of the study horses that received both butorphanol and phenylbutazone was a result of decreased perception of pain and, therefore, increased comfort; such prolonged recumbency in colts that received both drugs has been reported previously. 30 Marked to moderate nociceptive response to castration has been detected in horses when a volatile anesthetic agent is used 13,14,38,39 or during standing laparoscopic castration. 40 Intratesticular administration of lidocaine significantly decreases arterial blood pressure and cremaster muscle tension in horses that are castrated under isoflurane anesthesia.…”

Section: Discussionmentioning

confidence: 99%

Analgesic effects of butorphanol tartrate and phenylbutazone administered alone and in combination in young horses undergoing routine castration

Sanz¹,

Sellon²,

Cary³

et al. 2009

javma

View full text Add to dashboard Cite

Objective-To compare the analgesic efficacy of administration of butorphanol tartrate, phenylbutazone, or both drugs in combination in colts undergoing routine castration. Design-Randomized controlled clinical trial. Animals-36 client-owned colts. Procedures-Horses received treatment with butorphanol alone (0.05 mg/kg [0.023 mg/ lb], IM, prior to surgery and then q 4 h for 24 hours), phenylbutazone alone (4.4 mg/kg [2.0 mg/lb], IV, prior to surgery and then 2.2 mg/kg [1.0 mg/lb], PO, q 12 h for 3 days), or butorphanol and phenylbutazone at the aforementioned dosages (12 horses/group). For single-drug-treated horses, appropriate placebos were administered to balance treatment protocols among groups. All horses were anesthetized, and lidocaine hydrochloride was injected into each testis. Physical and physiological variables, plasma cortisol concentration, body weight, and water consumption were assessed before and at intervals after surgery, and induction of and recovery from anesthesia were subjectively characterized. Observers assessed signs of pain by use of a visual analogue scale and a numerical rating scale. Results-Significant changes in gastrointestinal sounds, fecal output, and plasma cortisol concentrations were evident in each treatment group over time, compared with preoperative values. At any time point, assessed variables and signs of pain did not differ significantly among groups, although the duration of recumbency after surgery was longest for the butorphanol-phenylbutazone-treated horses. Conclusions and Clinical Relevance-With intratesticular injections of lidocaine, administration of butorphanol to anesthetized young horses undergoing routine castration had the same apparent analgesic effect as phenylbutazone treatment. Combined butorphanolphenylbutazone treatment was not apparently superior to either drug used alone. (J Am Vet

show abstract

Section: Discussionmentioning

confidence: 99%

Analgesic effects of butorphanol tartrate and phenylbutazone administered alone and in combination in young horses undergoing routine castration

Sanz¹,

Sellon²,

Cary³

et al. 2009

javma

View full text Add to dashboard Cite

show abstract

“…In previous studies a reduction in d and u power and a subsequent increase in MF have been suggested as specific indicators for nociception related EEG arousal reaction (Freye et al 1999, Murrel et al 2003, while an increase in power in the a frequency band was correlated with cortical reactivation resulting from reduced hypnosis (Freye et al 1999). This assumption is in contrast to previous reports suggesting that both activation of the ARAS by afferent nociceptive impulses on one hand (Pichlmayr et al 1983, Rö pcke et al 2001) and the action of opioid analgesics on the other hand (Pichlmayr et al 1983, Scott et al 1985 result in unspecific EEG changes, such as an increase in frequency content and EEG slowing, respectively.…”

Section: Electroencephalogram Responses To Noxious Stimulationmentioning

confidence: 95%

EEG power spectrum analysis for monitoring depth of anaesthesia during experimental surgery

Otto

2008

Lab Anim

View full text Add to dashboard Cite

SummaryThe first attempts to introduce computerized power spectrum analysis of the electroencephalogram (EEG) as an intraoperative anaesthesia monitoring device started approximately 30 years ago. Since that time, the effects of various anaesthetic agents, sedative and analgesic drugs on the EEG pattern have been addressed in numerous studies in human patients and different animal species. These studies revealed dose-dependent changes in the EEG power spectrum for many intravenous and volatile anaesthetics. Moreover, EEG responses evoked by surgical stimuli during relative light levels of surgical anaesthesia have been classified as 'arousal' and 'paradoxical arousal' reaction, previously referred to as 'desynchronization' and 'synchronization', respectively. Contrasting reports on the correlation between quantitative EEG (QEEG) variables derived from power spectrum analysis (i.e. spectral edge frequency, median frequency) and simultaneously recorded clinical signs such as movement and haemodynamic responses, however, limited the routine use of intraoperative EEG monitoring. In addition, the appearance of EEG burst suppression pattern and isoelectricity at clinically relevant concentrations/doses of newer general anaesthetics (i.e. isoflurane, sevoflurane, propofol) may have weakened the dose-related EEG changes previously reported. Despite these findings, the EEG power spectrum analysis may still provide valuable information during intraoperative monitoring in the individual subject. The information obtained from EEG power spectrum analysis may be further supplemented by newer EEG indices such as bispectral index and approximate entropy or other neurophysiological monitors including auditory evoked potentials or somatosensory evoked potentials.

show abstract

“…Based upon combinations of fourteen electrodes with eight channels, reference and bipolar montages have been utilized in clinical cases in dogs (4). For evaluation of halothane anesthesia in horses and ponies during castration, the active electrode was placed on the zygomatic process, the reference electrode over the parietal suture rostral to divergence of temporal muscles from the midline, and the ground electrode caudal to the poll (5). Electroencephalographic and behavioral alterations were studied in kids subjected to stress of physical separation from their biological dams utilizing a five lead-based montage (6).…”

Section: Introductionmentioning

confidence: 99%

Electroencephalographic electrode montage in goats: topographical, radiological, and physiological assessment

Madan¹,

Rastogi²,

Das³

et al. 2017

Turk J Vet Anim Sci

View full text Add to dashboard Cite

The paucity of information on assortment of EEG leads in goats has hampered analysis of brain regional activity during different physiological, pathological, and ethological conditions in this species. Hence, the present study was designed to develop a montage with suitable combinations of EEG electrode arrays in goats. Ten specimens of freshly slaughtered goat heads (crossbreed of Jamunapari) were procured and preserved at -20 °C. Frozen samples were sliced sagittally and transversely to corroborate the link between intended topographic landmarks for EEG leads over the scalp and underlying provinces of the brain. Based on these observations, nine sites for EEG electrode placement were finalized so as to include the entire cerebral cortex. These electrode placement sites were further checked through another set of five goat heads. The electrode sites were then extrapolated to live animals for radiological (orthogonally) and physiological validation. The montage derived on basis on these electrode placement sites provided maximum brain coverage and they were found suitable for EEG in goats. Parietal and vertex areas of the brain were found to be most active during the resting phase with the right hemisphere exhibiting more activity than the left. The results indicated right hemisphere conservatism and an attentional process during the resting phase in goats.

show abstract

Changes in the EEG during castration in horses and ponies anaesthetized with halothane

Cited by 90 publications

References 42 publications

Analgesic effects of butorphanol tartrate and phenylbutazone administered alone and in combination in young horses undergoing routine castration

Analgesic effects of butorphanol tartrate and phenylbutazone administered alone and in combination in young horses undergoing routine castration

EEG power spectrum analysis for monitoring depth of anaesthesia during experimental surgery

Electroencephalographic electrode montage in goats: topographical, radiological, and physiological assessment

Contact Info

Product

Resources

About