• Analytical Science and Technology
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• v.35 no.3
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• pp.136-142
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• 2022

According to media reports, the carcasses of euthanized abandoned dogs were processed at high temperature and pressure to make powder, and then used as feed materials (meat and bone meal), raising the possibility of residuals in the feed of the anesthetic ketamine and dexmedetomidine used for euthanasia. Therefore, a simultaneous analysis method using QuEChERS combined with high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry was developed for rapid residue analysis. The method developed in this study exhibited linearity of 0.999 and higher. Selectivity was evaluated by analyzing blank and spiked samples at the limit of quantification. The MRM chromatograms of blank samples were compared with those of spiked samples with the analyte, and there were no interferences at the respective retention times of ketamine and dexmedetomidine. The detection and quantitation limits of the instrument were 0.6 ㎍/L and 2 ㎍/L, respectively. The limit of quantitation for the method was 10 ㎍/kg. The results of the recovery test on meat and bone meal, meat meal, and pet food showed ketamine in the range of 80.48-98.63 % with less than 5.00 % RSD, and dexmedetomidine in the range of 72.75-93.00 % with less than 4.83 % RSD. As a result of collecting and analyzing six feeds, such as meat and bone meal, prepared at the time the raw material was distributed, 10.8 ㎍/kg of ketamine was detected in one sample of meat and bone meal, while dexmedetomidine was found to have a concentration below the limit of quantitation. It was confirmed that the detected sample was distributed before the safety issue was known, and thereafter, all the meat and bone meal made with the carcasses of euthanized abandoned dogs was recalled and completely discarded. To ensure the safety of the meat and bone meal, 32 samples of the meat and bone meal as well as compound feed were collected, and additional residue investigations were conducted for ketamine and dexmedetomidine. As a result of the analysis, no component was detected. However, through this investigation, it was confirmed that some animal drugs, such as anesthetics, can remain without decomposition even at high temperature and pressure; therefore, there is a need for further investigation of other potentially hazardous substances not controlled in the feed.

• Journal of The Korean Dental Society of Anesthesiology
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• v.13 no.4
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• pp.161-166
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• 2013

Dexmedetomidine is a potent alpha-2-adrenergic agonist, more selective than clonidine, with widespread actions on the mammalian brain. A large body of recent work supports its analgesia and sympatholytic properties. Dexmedetomidine is a useful medication with many clinical applications. The medication has shown efficacy in decreasing the need for opioids, benzodiazepines, propofol, and other sedative medications. Dexmedetomidine has been used effectively for sedation during invasive procedures and in the ICU. Short-term sedation has been shown to be safe in studies, although hypotension and bradycardia are the most significant side effects. Dexmedetomidine is emerging as an effective therapeutic agent in the management of a wide range of clinical conditions with an efficacious, safe profile.

• Journal of Veterinary Clinics
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• v.32 no.5
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• pp.422-425
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• 2015

This study evaluated the myocardial performance on echocardiography after the sedation/anesthesia of medetomidine (D), the combination of medetomidine and tiletamine/zolazepam (DZ), and the combination of medetomidine, tiletamine/zolazepam and tramadol (DZT) in Beagle dogs. Ten healthy adult Beagle dogs (weighing $8.6{\pm}1.0kg$) were enrolled in this study. Heart rate (HR), fractional shortening (%FS), left ventricular ejection fraction (%LVEF), stroke volume (SV), cardiac output (CO), left ventricular internal diameter in systole (LVIDs) and left ventricular internal diameter in diastole (LVIDd) using M-mode echocardiography were measured prior to anesthesia, then every 10 min for 60 min. The HR, %FS, %LVEF, SV and CO were significantly decreased during sedation/anesthesia with D, DZ and DZT combination of anesthesia. Although those anesthetic protocols provided acceptable quality of sedation/anesthesia, levels of cardiovascular suppression were substantial and persistent and thus the continuous monitoring on vital signs should be accompanied in any situation. Close attention is required for dogs with pre-existing heart diseases, when those anesthetic protocols were applied.

• Journal of Veterinary Clinics
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• v.27 no.2
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• pp.136-141
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• 2010

The aim of this study is to investigate whether medetomidine (MED) and tiletamine/zolazepam (ZT) combination in dogs provide the sufficient analgesia during the period of the stage of surgical anesthesia determined by the response to the noxious stimuli, which were evaluated by the change of electroencephalogram (EEG) and hemodynamic values. Seven clinically healthy, adult beagle dogs were used. They were used repeatedly at interval of a week, according to a randomized design. This study had 2 experimental groups. In Group 1, dogs received $30\;{\mu}g/kg$ of medetomidine and 10 mg/kg of tiletamine/zolazepam. Both drugs were administered intramuscularly. In Group 2, dogs were medicated with the same method as in Group 1, except the pedal withdrawal reflex test was done. In Group 2, interdigital regions were grasped with a mosquito forceps for 30 seconds, every 5 min from 10 min to 45 min after ZT injection. During all recording stages, the power for each band, mean arterial pressure and heart rates were calculated. On EEG, no significant changes were observed between groups. Although mean arterial pressure and heart rate were increased 10 min after ZT injection, no significant differences were observed between groups. In conclusion, the MED and ZT anesthesia in dogs are seemed to provide a satisfactory analgesic effect during the period of surgical anesthesia based on EEG with pedal withdrawal reflex test.

• Journal of The Korean Dental Society of Anesthesiology
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• v.14 no.3
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• pp.151-155
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• 2014

Background: Dexmedetomidine is known to be administered for sedation safely even in a very elderly patient. The purpose of this study was to determine the effect of age on clinically optimal dose of dexmedetomidine for sedation. Methods: We enrolled 50 patients ASA class I and II, scheduled for lower extremity surgery that need. They were classified into a young group (n = 26), aged below 75 and an old group (n = 24), aged above 75. Dexmedetomidine was continuously infused $0.5{\mu}g/kg$ within 10 min, followed by maintenance at a dose of $0.5{\mu}g/kg/min$, initially. The next dose was selected using the Dixon's up-and-down method. Results: The cED50 of dexmedetomidine required to maintain optimal sedation level in young and old group were 0.50 and $0.48{\mu}g/kg$, respectively. With isotonic regression, cED95 of dexmedetomidine was $0.71{\mu}g/kg$ (95% confidence intervals $0.57-1.06{\mu}g/kg$) and $0.58{\mu}g/kg$ (95% confidence intervals $0.51-0.67{\mu}g/kg$). There were no significant differences in cED50 (P = 0.21), recovery variables, or incidence of side effects between the two groups. Conclusions: Clinically optimal dose of dexmedetomidine was not affected to the age during sedation.

• Journal of Veterinary Clinics
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• v.27 no.6
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• pp.674-678
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• 2010

The effects of medetomidine on the degree of analgesia and sedation in rats were evaluated. The rats were randomly divided into six groups: saline, 1 mL/kg (group 'Saline'); butorphanol, 2.0 mg/kg; medetomidine, 0.2, 0.4, 0.8 or 1.6 mg/kg (group 'MED0.2', 'MED0.4', 'MED0.8' and 'MED1.6', respectively). The degree of analgesia was measured in the $50^{\circ}C$ hot-water tail-flick latency test, and the degree of sedation was evaluated using the numerical sedation score (NSS) and the righting reflex. All doses of medetomidine, except MED0.2, significantly increased the analgesic effect compared to the Saline group. Variables in the MED0.4 and MED0.8 groups, but not in the MED1.6 group, were significantly increased compared to those in the MED0.2 group. However, analgesia with all doses of medetomidine was not significantly different compared to that with butorphanol. Saline and butorphanol treatments did not induce sedation and loss of righting reflex during the recording period. NSS in the MED0.4, MED0.8 and MED1.6 groups were significantly higher than that in the MED0.2 group. NSS in the MED0.8 and MED1.6 groups were not significantly different from that in the MED0.4 group. The latency to loss of righting reflex in the MED0.8 and MED1.6 groups decreased significantly compared to that in the MED0.2 group. Thus, 0.4 and 0.8 mg/kg of medetomidine provided not only reliable analgesia but also sedation to rats. In conclusion, 0.4 to 0.8 mg/kg medetomidine could be a useful chemical restraint method in rats.

• Journal of Veterinary Clinics
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• v.26 no.4
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• pp.317-323
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• 2009

This study was performed to evaluate the effect of intravenous administration of glycopyrrolate on cardiovascular and respiratory system in dogs given intravenous medetomidine (20 ${\mu}g$/kg) and intramuscular midazolam (0.3 mg/kg) (MM). Prior to administration of MM, glycopyrrolate was administered intravenously at doses of 5 ${\mu}g$/kg (Gly-5), 10 ${\mu}g$/kg (Gly-10) or 20 ${\mu}g$/kg (Gly-20), respectively. For the control group saline was administered intravenously. In the cardiovascular system, HR, BP, RAP, PAWP, CI, SI, SVR, and PVR were measured. RR, $V_T$, $P_{ETCO2}$, and arterial blood gas analysis were measured for respiratory system. Although rapid and satisfied depth of sedation was obtained by MM, life-threatening bradycardia, the outstanding side-effect on cardiovascular system in dogs were observed. This combination also decreased CO and increased SVR, RAP, and PAWP significantly. The bradycardia could be prevented in all the glycopyrrolate treated groups, but tachycardia was observed in Gly-10 and Gly-20 groups. Significant increases in blood pressure were shown in glycopyrrolate treated groups. Also, tachycardia depends on dose of glycopyrrolate, compensating the CO. However, these were not fully reserved. In conclusion, MM combination could induce rapid and satisfied depth of sedation but was not the suitable method for the deep sedation of dogs with cardiovascular or circulatory problems.