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1.
Bruno H. Pypendop Juhana Honkavaara Jan E. Ilkiw 《Veterinary anaesthesia and analgesia》2017,44(1):52-62
Objective
To characterize the cardiovascular effects of dexmedetomidine, with or without MK-467, following intravenous (IV) administration in cats.Study design
Prospective Latin square experimental study.Animals
Six healthy adult purpose-bred cats.Methods
Cats were anesthetized with desflurane in oxygen for instrumentation with a carotid artery catheter and a thermodilution catheter in the pulmonary artery. One hour after discontinuation of desflurane, cats were administered dexmedetomidine (25 μg kg–1), MK-467 (600 μg kg–1), or dexmedetomidine (25 μg kg–1) and MK-467 (600 μg kg–1). All treatments were administered IV as a bolus. Cardiovascular variables were measured prior to drug administration and for 8 hours thereafter. Only data from the dexmedetomidine and dexmedetomidine–MK-467 treatments were analyzed.Results
Dexmedetomidine produced significant decreases in heart rate, cardiac index and right ventricular stroke work index, and significant increases in arterial blood pressure, central venous pressure, pulmonary artery pressure and systemic vascular resistance index. Dexmedetomidine combined with MK-467 resulted in significant but transient decrease in blood pressure and right ventricular stroke work index.Conclusion and clinical relevance
Following IV co-administration, MK-467 effectively attenuated dexmedetomidine-induced cardiovascular effects in cats. The drug combination resulted in transient reduction in arterial blood pressure, without causing hypotension. 相似文献2.
3.
Objective
To study the effects of MK-467, a peripheral α2-adrenoceptor antagonist, on sedation, heart rate and blood pressure after intramuscular (IM) coadministration with 25 μg kg?1 of dexmedetomidine in cats.Study design
Prospective, randomized, controlled, blinded, cross-over, experimental study.Animals
A total of eight healthy, adult, neutered male cats.Methods
Cats were administered five IM treatments at least 2 weeks apart, consisting of dexmedetomidine 25 μg kg?1 (D25), MK-467 600 μg kg?1 (M600) and D25 combined with 300, 600 and 1200 μg kg?1 of MK-467 (D25M300, D25M600 and D25M1200, respectively). Heart rate and direct arterial blood pressure were recorded via telemetry and sedation assessed prior to treatments and at intervals for 8 hours thereafter.Results
Heart rate decreased significantly after all treatments with dexmedetomidine and remained below baseline up to 240 (D25), 20 (D25M300) and 3 minutes (D25M600 and D25M1200). Mean arterial pressure (MAP) increased with D25, remained unchanged with M600 and decreased over time with all combination treatments. The highest and lowest MAP after each treatment were 168 ± 17 and 100 ± 14 (D25), 157 ± 18 and 79 ± 11 (D25M300), 153 ± 11 and 74 ± 10 (D25M600), 144 ± 12 and 69 ± 7 (D25M1200) and 136 ± 9 and 104 ± 13 mmHg (M600). All treatments with dexmedetomidine produced sedation although its duration was significantly reduced by the addition of MK-467.Conclusions and clinical relevance
Dexmedetomidine induced bradycardia and hypertension, which were attenuated by all three doses of MK-467. The duration of sedation was reduced by MK-467. MK-467 may improve the cardiovascular tolerance of IM dexmedetomidine in cats. 相似文献4.
Kristine T. Siao Bruno H. Pypendop Juhana Honkavaara Jan E. Ilkiw 《Veterinary anaesthesia and analgesia》2017,44(5):1101-1115
Objective
To characterize the hemodynamic effects of dexmedetomidine, with or without MK-467, following intramuscular (IM) administration in cats.Study design
Randomized, crossover, experimental study.Animals
Six healthy adult male castrated purpose-bred cats.Methods
Cats were anesthetized with isoflurane in oxygen and instrumented. Cats were administered dexmedetomidine (25 μg kg?1), with (DM) or without (D) MK-467 (600 μg kg?1), IM in the epaxial muscles. Cardiovascular variables, respiratory variables, temperature, and arterial and mixed-venous pH, blood gases and electrolytes were measured prior to drug administration and at various time points for 6 hours thereafter, during anesthesia with isoflurane. Additional variables were calculated from the measurements, using standard equations. Results were analyzed with a two-way repeated-measures analysis of variance, followed by Dunnett’s and paired t tests where appropriate.Results
Dexmedetomidine resulted in a significant decrease in cardiac index (CI) and significant increases in mean arterial pressure (MAP) and systemic vascular resistance index (SVRI). The addition of MK-467 failed to prevent most of the early cardiovascular effects of dexmedetomidine, but the duration of systemic vasoconstriction was shorter and CI did not decrease. The lowest and highest post-treatment values in each treatment were 0.1 ± 0.03 and 0.13 ± 0.03 L minute?1 BW?0.67 (D) versus 0.14 ± 0.01 and 0.19 ± 0.03 L minute?1 BW?0.67 (DM) for CI, 87 ± 13 and 181 ± 21 mmHg (D) versus 70 ± 11 and 153 ± 18 mmHg (DM) for MAP and 58,948 ± 17,754 and 119,432 ± 40,423 dynes second cm?5 BW?0.67 (D) versus 25,870 ± 3782 and 76,498 ± 17,258 dynes second cm?5 BW?0.67 (DM) for SVRI, respectively.Conclusion and clinical relevance
IM coadministration of MK-467 and dexmedetomidine in isoflurane-anesthetized cats shortened dexmedetomidine-induced cardiovascular effects. This drug combination may be useful in cats in which longer-lasting hypertension and hemodynamic depression is of concern. 相似文献5.
Flavia Restitutti M. Johanna Kaartinen Marja R. Raekallio Otto Wejberg Emmi Mikkola Jerome R.E. del Castillo Mika Scheinin Outi M. Vainio 《Veterinary anaesthesia and analgesia》2017,44(3):417-426
Objective
We investigated the plasma concentrations and cardiovascular effects of intramuscularly (IM) administered medetomidine, administered alone or with three different doses of MK-467.Study design
Prospective, randomized, open, crossover trial.Animals
Eight purpose-bred healthy Beagle dogs.Methods
Each dog was administered four treatments: medetomidine 20 μg kg–1 IM alone or mixed in the same syringe with MK-467 (200 μg kg–1, 400 μg kg–1 or 600 μg kg–1). Instrumentation was performed under standardized anaesthesia. The dogs were allowed to recover before measurement of baseline values. Composite sedation scores, cardiovascular variables, i.e., heart rate (HR), cardiac output (CO), mean arterial and central venous blood pressures (MAP and CVP) and arterial blood gases were recorded at baseline and for 60 minutes after treatment. Drug concentrations in venous plasma were analysed. Generalized linear mixed models for repeated measures with post hoc Bonferroni correction were used with statistical significance level set at α = 0.05.Results
All treatments initially demonstrated the effects of medetomidine: HR and CO decreased and CVP increased. MAP transiently increased and then significantly decreased from baseline with the two highest MK-467 doses. The cardiovascular effects of medetomidine disappeared more rapidly with MK-467 than with medetomidine alone. With medetomidine alone, sedation scores remained high until the end of the 60 minute follow-up. Maximum concentrations of medetomidine were more rapidly achieved and were higher with MK-467.Conclusions and clinical relevance
Initial haemodynamic effects of medetomidine were not prevented by MK-467, but these effects were attenuated and their duration shortened by MK-467, independently of dose. Absorption of medetomidine was accelerated by MK-467, when administered concomitantly IM, resulting in faster sedation; addition of MK-467 shortened the sedative effect of medetomidine. 相似文献6.
Thomas A. Trein Beatriz P. Floriano Juliana T. Wagatsuma Joana Z. Ferreira Guilherme L. da Silva Paulo S.P. dos Santos Sílvia H.V. Perri Valéria NLS. Oliva 《Veterinary anaesthesia and analgesia》2017,44(1):144-153
Objective
To evaluate motor and sensory blockade of combining dexmedetomidine with ropivacaine, administered perineurally or systemically, for femoral and sciatic nerve blocks in conscious dogs.Study design
Randomized, controlled, experimental study.Animals
Seven healthy Beagle dogs, aged 3.3 ± 0.1 years and weighing 11.0 ± 2.4 kg.Methods
Dogs were anesthetized with isoflurane on three separate occasions for unilateral femoral and sciatic nerve blocks and were administered the following treatments in random order: perineural ropivacaine 0.75% (0.1 mL kg–1) on each nerve and intramuscular (IM) saline (0.2 mL kg–1) (GCON); perineural dexmedetomidine (1 μg mL–1) and ropivacaine 0.75% (0.1 mL kg–1) on each nerve and IM saline (0.2 mL kg–1) (GDPN); and perineural ropivacaine 0.75% (0.1 mL kg–1) on each nerve and IM dexmedetomidine (1 μg mL–1, 0.2 mL kg–1) (GDIM). Nerve blocks were guided by ultrasound and electrical stimulation and dogs were allowed to recover from general anesthesia. Sensory blockade was evaluated by response to clamp pressure on the skin innervated by the saphenous/ femoral, common fibular and tibial nerves. Motor blockade was evaluated by observing the ability to walk and proprioception. Sensory and motor blockade were evaluated until their full recovery.Results
No significant differences in onset time to motor and sensory blockade were observed among treatments. Duration of motor blockade was not significantly different among treatments; however, duration of tibial sensory blockade was longer in the GDPN than in the GDIM treatment.Conclusions and clinical relevance
Although a longer duration of sensory blockade was observed with perineural dexmedetomidine, a significant increase compared with the control group was not established. Other concentrations should be investigated to verify if dexmedetomidine is a useful adjuvant to local anesthetics in peripheral nerve blocks in dogs. 相似文献7.
Matheus R. Ribeiro Carolina B. de Carvalho Ricardo H.Z. Pereira Gabriel M. Nicácio Rejane B. Brinholi Renata N. Cassu 《Veterinary anaesthesia and analgesia》2017,44(5):1236-1244
Objective
To evaluate the analgesic efficacy of Yamamoto New Scalp Acupuncture (YNSA) as an adjuvant for postoperative pain management in cats.Study design
Prospective, randomized, blinded, clinical study.Animals
Twenty cats aged (mean ± standard deviation) 25 ± 9 months and weighing 2.7 ± 0.6 kg undergoing ovariohysterectomy.Methods
The cats were sedated with intramuscular (IM) ketamine (5 mg kg?1), midazolam (0.5 mg kg?1) and tramadol (2 mg kg?1). The cats were randomly distributed before induction of anesthesia into two groups of 10 cats each: group YNSA, in which bilateral basic D points were stimulated with a dry needle from 20 minutes prior to anesthetic induction to the end of the surgery; group Control, in which no acupuncture was applied. Postoperative analgesia was assessed at 1, 2, 4, 8, 12, 18 and 24 hours postextubation using an Interactive Visual Analog Scale and Universidade Estadual Paulista-Botucatu Multidimensional Composite Pain Scale (UNESP-Botucatu MCPS). Rescue analgesia was provided with IM tramadol (2 mg kg?1), and the pain scores were reassessed 30 minutes after rescue intervention. If the analgesia remained insufficient, meloxicam (0.2 mg kg?1 as a single dose) was administered IM. Data were analyzed using Student t-test, Fisher exact test, Mann–Whitney U test and Friedman test (p < 0.05).Results
Significantly lower pain scores were observed in YNSA when compared with Control at 1–4 hours based on the UNESP-Botucatu MCPS scores. Although significant differences were not identified between groups requiring rescue analgesia, additional postoperative analgesia was administered to four of 10 cats in Control and no cats in YNSA.Conclusion and clinical relevance
Perioperative YNSA resulted in decreased pain scores and a reduction in postoperative requirement for rescue analgesia in cats. This method should be considered a viable option as an adjuvant analgesic therapy for cats undergoing ovariohysterectomy. 相似文献8.
Ryan S. Bailey Linda S. Barter Bruno H. Pypendop 《Veterinary anaesthesia and analgesia》2017,44(4):876-882
Objective
To characterize the pharmacokinetics of dexmedetomidine when administered as a short intravenous (IV) infusion to isoflurane-anesthetized rabbits.Study design
Experimental study.Animals
A total of six healthy adult female New Zealand White rabbits.Methods
Rabbits were anesthetized with isoflurane in oxygen. Following determination of isoflurane minimum alveolar concentration (MAC), the anesthetic dose was reduced to 0.7 × MAC, and dexmedetomidine hydrochloride (20 μg kg?1) was infused IV over 5 minutes. Arterial blood samples were obtained immediately before and at 1, 2, 5, 6, 7, 10, 15, 30, 60, 90, 120, 240 and 360 minutes following termination of the infusion. Samples were transferred into tubes containing ethylenediaminetetraacetic acid and centrifuged immediately. The plasma was harvested and stored at –80 °C until analyzed. Concentrations of dexmedetomidine in plasma were determined by liquid chromatography mass spectrometry. Compartment models were fitted to the time and concentration data using nonlinear regression.Results
A three-compartment model best fit the data set. Median volume of distribution at steady state and terminal half-life were 3169 mL kg?1 (range, 2182–3859 mL kg?1) and 80 minutes (range, 72–88 minutes), respectively.Conclusions and clinical relevance
The pharmacokinetics of dexmedetomidine in isoflurane-anesthetized, healthy, New Zealand White rabbits were characterized in this study. Data from this study can be used to determine dosing regimens for dexmedetomidine in isoflurane-anesthetized rabbits. 相似文献9.
10.
Ignacio Lizarraga Fernanda Castillo-Alcala Lauren S. Robinson 《Veterinary anaesthesia and analgesia》2017,44(3):509-517
Objective
To assess and compare the sedative and antinociceptive effects of four dosages of dexmedetomidine in donkeys.Study design
Randomized, controlled, crossover, Latin-square, blinded study.Animals
Six healthy, castrated, adult, standard donkeys.Methods
Dexmedetomidine (2, 3, 4 and 5 μg kg?1; D2, D3, D4 and D5), acepromazine (0.1 mg kg?1) and saline were administered intravenously to each donkey and a 1 week interval was allowed between successive trials on each animal. Sedation scores (SS) and head heights above ground (HHAG) were used to assess sedation and mechanical nociceptive threshold (MNT) testing to assess antinociception over 120 minutes post-treatment. Areas under the curve (AUC) for 0–30, 30–60 and 60–120 minutes were computed to compare the effect of treatments.Results
SS-AUC0–30 values were larger for D4 and D5, and SS-AUC30–60 values were larger for D5 than for saline. All dexmedetomidine treatments produced lower HHAG-AUC0–30 and HHAG-AUC30–60 values, and acepromazine produced lower HHAG AUC60–120 values than did saline. For MNT, D3, D4 and D5 increased AUC0–30 and AUC30–60 values compared with saline and also AUC0–30 values compared with D2 and acepromazine. Smaller MNT-AUC30–60 values were obtained with D2 than with D4 and D5, with D3 than with D5, and with acepromazine than with D4 and D5.Conclusions and clinical relevance
Dexmedetomidine induced sedation and dosage-dependent mechanical antinociception. Larger dexmedetomidine dose rates were required to induce antinociception than sedation. Furthermore, the antinociception induced by dexmedetomidine was of shorter duration than its sedation. For minor painful procedures on standing donkeys, D5 may be clinically useful to provide sedation and analgesia. 相似文献11.
Carlos Ros Carme Soler Alejandra García de Carellán Mateo 《Veterinary anaesthesia and analgesia》2017,44(5):1085-1090
Objective
To compare the effects of general anaesthesia using sevoflurane or alfaxalone on the brainstem auditory evoked response (BAER) test in adult healthy cats.Study design
Prospective, clinical, ‘blinded’, crossover study.Animals
Ten feral adult healthy cats.Methods
Premedication consisted of dexmedetomidine (0.01 mg kg–1) intramuscularly (IM). The first general anaesthesia was induced and maintained with sevoflurane (treatment S) for physical examination, BAER test, complete blood tests, thoracic radiographs and abdominal ultrasound. The second general anaesthesia was induced with alfaxalone (treatment A) IM (2 mg kg–1) and maintained with alfaxalone (10 mg kg–1 hour–1) for the BAER test, followed by neutering surgery.The BAER recordings were compared for differences in latencies, amplitudes and waveform morphology. Data were analysed using Student's t test and Wilcoxon rank test for paired samples for parametric and non-parametric data, respectively. Statistical significance was set at p < 0.05.Results
General anaesthesia was uneventful; normal BAER comprising five peaks could be identified in both treatments. Mean ± SD latencies were 1.05 ± 0.09, 1.83 ± 0.11, 2.52 ± 0.19, 3.43 ± 0.17 and 4.39 ± 0.15 ms and 1.03 ± 0.04, 1.81 ± 0.73, 2.53 ± 0.15, 3.37 ± 0.13 and 4.33 ± 0.13 ms in treatments S and A, respectively. Median (interquartile range) amplitudes were 2.83 (0.67), 1.27 (0.41), 0.30 (0.40), 1.05 (0.82), 0.61 (0.38) microvolts and 2.84 (1.21), 1.49 (1.18), 0.26 (0.32), 0.91 (0.50) and 0.92 (0.64) microvolts in treatments S and A, respectively. There were no statistically significant differences in mean latencies or median amplitudes between both the anaesthetics.Conclusions and clinical relevance
This study demonstrates that there were no statistically significant differences between both the anaesthetics on the BAER test in adult healthy cats. Moreover, two possible anaesthetic protocols are described for cats undergoing this electrodiagnostic test. 相似文献12.
Yael Shilo-Benjamini Bruno H. Pypendop Georgina Newbold Peter J. Pascoe 《Veterinary anaesthesia and analgesia》2017,44(1):178-182
Objective
To determine plasma bupivacaine concentrations after retrobulbar or peribulbar injection of bupivacaine in cats.Study design
Randomized, crossover, experimental trial with a 2 week washout period.Animals
Six adult healthy cats, aged 1–2 years, weighing 4.6 ± 0.7 kg.Methods
Cats were sedated by intramuscular injection of dexmedetomidine (36–56 μg kg?1) and were administered a retrobulbar injection of bupivacaine (0.75 mL, 0.5%; 3.75 mg) and iopamidol (0.25 mL), or a peribulbar injection of bupivacaine (1.5 mL, 0.5%; 7.5 mg), iopamidol (0.5 mL) and 0.9% saline (1 mL) via a dorsomedial approach. Blood (2 mL) was collected before and at 5, 10, 15, 22, 30, 45, 60, 120, 240 and 480 minutes after bupivacaine injection. Atipamezole was administered approximately 30 minutes after bupivacaine injection. Plasma bupivacaine and 3-hydroxybupivacaine concentrations were determined using liquid chromatography–mass spectrometry. Bupivacaine maximum plasma concentration (Cmax) and time to Cmax (Tmax) were determined from the data.Results
The bupivacaine median (range) Cmax and Tmax were 1.4 (0.9–2.5) μg mL?1 and 17 (4–60) minutes, and 1.7 (1.0–2.4) μg mL?1, and 28 (8–49) minutes, for retrobulbar and peribulbar injections, respectively. In both treatments the 3-hydroxybupivacaine peak concentration was 0.05–0.21 μg mL?1.Conclusions and clinical relevance
In healthy cats, at doses up to 2 mg kg?1, bupivacaine peak plasma concentrations were approximately half that reported to cause arrhythmias or convulsive electroencephalogram (EEG) activity in cats, and about one-sixth of that required to produce hypotension. 相似文献13.
14.
Rachel C. Hector Marlis L. Rezende Khursheed R. Mama Eugene P. Steffey Heather K. Knych Ann M. Hess Juhana M. Honkavaara Marja R. Raekallio Outi M. Vainio 《Veterinary anaesthesia and analgesia》2017,44(4):755-765
Objective
To determine the effects of low and high dose infusions of dexmedetomidine and a peripheral α2-adrenoceptor antagonist, MK-467, on sevoflurane minimum alveolar concentration (MAC) in dogs.Study design
Crossover experimental study.Animals
Six healthy, adult Beagle dogs weighing 12.6 ± 0.9 kg (mean ± standard deviation).Methods
Dogs were anesthetized with sevoflurane in oxygen. After a 60-minute instrumentation and equilibration period, the MAC of sevoflurane was determined in triplicate using the tail clamp technique. PaCO2 and temperature were maintained at 40 ± 5 mmHg (5.3 ± 0.7 kPa) and 38 ± 0.5 ºC, respectively. After baseline MAC determination, dogs were administered two incremental loading and infusion doses of either dexmedetomidine (1.5 μg kg?1 then 1.5 μg kg?1 hour?1 and 4.5 μg kg?1 then 4.5 μg kg?1 hour?1) or MK-467 (90 μg kg?1 then 90 μg kg?1 hour?1 and 180 μg kg?1 then 180 μg kg?1 hour?1); loading doses were administered over 10 minutes. MAC was redetermined in duplicate starting 30 minutes after the start of drug administration at each dose. End-tidal sevoflurane concentrations were corrected for calibration and adjusted to sea level. A repeated-measures analysis was performed and comparisons between doses were conducted using Tukey's method. Statistical significance was considered at p < 0.05.Results
Sevoflurane MAC decreased significantly from 1.86 ± 0.3% to 1.04 ± 0.1% and 0.57 ± 0.1% with incremental doses of dexmedetomidine. Sevoflurane MAC significantly increased with high dose MK-467, from 1.93 ± 0.3% to 2.29 ± 0.5%.Conclusions and clinical relevance
Dexmedetomidine caused a dose-dependent decrease in sevoflurane MAC, whereas MK-467 caused an increase in MAC at the higher infusion dose. Further studies evaluating the combined effects of dexmedetomidine and MK-467 on MAC and cardiovascular function may elucidate potential benefits of the addition of a peripheral α2-adrenergic antagonist to inhalation anesthesia in dogs. 相似文献15.
Julia Deutsch Colette Jolliffe Emma Archer Elizabeth A. Leece 《Veterinary anaesthesia and analgesia》2017,44(4):794-802
Objective
To assess quality of sedation following intramuscular (IM) injection of two doses of alfaxalone in combination with butorphanol in cats.Study design
Prospective, randomized, ‘blinded’ clinical study.Animals
A total of 38 cats undergoing diagnostic imaging or noninvasive procedures.Methods
Cats were allocated randomly to be administered butorphanol 0.2 mg kg?1 combined with alfaxalone 2 mg kg?1 (group AB2) or 5 mg kg?1 (group AB5) IM. If sedation was inadequate, alfaxalone 2 mg kg?1 IM was administered and cats were excluded from further analysis. Temperament [1 (friendly) to 5 (aggressive)], response to injection, sedation score at 2, 6, 8, 15, 20, 30, 40, 50 and 60 minutes, overall sedation quality scored after data collection [1 (excellent) to 4 (inadequate)] and recovery quality were assessed. Heart rate (HR), respiratory rate (fR) and arterial haemoglobin saturation (SpO2) were recorded every 5 minutes. Groups were compared using t tests and Mann–Whitney U tests. Sedation was analysed using two-way anova, and additional alfaxalone using Fisher's exact test (p < 0.05).Results
Groups were similar for sex, age, body mass and response to injection. Temperament score was lower in group AB2 [2 (1–3)] compared to AB5 [3 (1–5)] (p = 0.006). Group AB5 had better sedation at 6, 8, 20 and 30 minutes and overall sedation quality was better in AB5 [1 (1–3)], compared to AB2 [3 (1–4)] (p = 0.0001). Additional alfaxalone was required for 11 cats in AB2 and two in AB5 (p = 0.005). Recovery quality, HR, fR and SpO2 were similar. Seven cats required oxygen supplementation. Complete recovery times were shorter in AB2 (81.8 ± 24.3 versus 126.6 ± 33.3 minutes; p = 0.009). Twitching was the most common adverse event.Conclusions and clinical relevance
In combination with butorphanol, IM alfaxalone at 5 mg kg?1 provided better quality sedation than 2 mg kg?1. Monitoring of SpO2 is recommended. 相似文献16.
Grayson A. Doss Dustin M. Fink Kurt K. Sladky Christoph Mans 《Veterinary anaesthesia and analgesia》2017,44(5):1175-1183
Objective
To compare dexmedetomidine–midazolam with alfaxalone–midazolam for sedation in leopard geckos (Eublepharis macularius).Study design
Prospective, randomized, blinded, complete crossover study.Animals
Nine healthy adult leopard geckos.Methods
Geckos were administered a combination of dexmedetomidine (0.1 mg kg?1) and midazolam (1.0 mg kg?1; treatment D–M) or alfaxalone (15 mg kg?1) and midazolam (1.0 mg kg?1; treatment A–M) subcutaneously craniodorsal to a thoracic limb. Heart rate (HR), respiratory rate (fR), righting reflex, palpebral reflex, superficial and deep pain reflexes, jaw tone and escape response were assessed every 5 minutes until reversal. Conditions for intubation and response to needle prick were evaluated. Antagonist drugs [flumazenil (0.05 mg kg?1) ± atipamezole (1.0 mg kg?1)] were administered subcutaneously, craniodorsal to the contralateral thoracic limb, 45 minutes after initial injection, and animals were monitored until recovery.Results
HR, but not fR, decreased significantly over time in both treatments. HR was significantly lower than baseline at all time points in D–M and for all but the 5 and 10 minute time points in A–M. HR was significantly higher in A–M at all time points after drug administration when compared with D–M. Sedation scores between protocols were similar for most time points. All animals in A–M lost righting reflex compared with seven out of nine (78%) geckos in D–M. Geckos in A–M lost righting reflex for significantly longer time. Mean ± standard deviation time to recovery after antagonist administration was 6.1 ± 2.2 minutes for D–M and 56 ± 29 minutes for A–M, and these times were significantly different.Conclusions and clinical relevance
Combination D–M or A–M provided sedation of a level expected to allow physical examinations and venipuncture in leopard geckos. A–M provided a faster onset of sedation compared with D–M. Recovery was significantly faster following antagonist reversal of D–M, compared with A–M. 相似文献17.
Hong-Xiu Diao Shuai Zhang Xue-Yuan Hu Wei Guan Li Luan Hai-Yu Liu Hong-Gang Fan 《Veterinary anaesthesia and analgesia》2017,44(1):114-120
Objective
To evaluate the behavior and some cardiopulmonary variables of dexmedetomidine–midazolam or dexmedetomidine–midazolam-butor-phanol in the silver fox (Vulpes vulpes).Study design
Blinded, randomized design.Animals
Sixteen adult silver foxes, aged 7–9 months, weighting 6.0–9.2 kg.Methods
Animals were randomly assigned to dexmedetomidine (50 μg kg?1) and midazolam (0.45 mg kg?1) (group DM) or to dexmedetomidine (30 μg kg?1), midazolam (0.45 mg kg?1) and butorphanol (0.25 mg kg?1) (group DMB), administered intramuscularly. Pulse rate (PR), respiratory rate (fR), noninvasive arterial pressures, oxygen saturation (SpO2), rectal temperature (T) and behavioral scores (posture, sedation, antinociception, jaw relaxation and auditory response) were measured at 5, 10, 20, 30, 40, 50 and 60 minutes after injection. Time from drug injection to recumbency with no response to stimuli (IT) and time from administration of atipamezole (0.2 mg kg?1) to standing with coordination (RT) were recorded. The occurrences of adverse events were recorded. Data were analyzed by two-tailed unpaired t-tests and Bonferroni post hoc tests. Significant differences were accepted at p<0.05.Results
There were no statistically significant differences between the groups for IT or RT. Arterial pressures were higher in DMB at each time point except at 5 minutes. PR was lower in DM at each time point except at 10 and 60 minutes. No significant difference was found between the groups for fR, SpO2 and T. The behavioral scores were significantly lower (lower quality immobilization) in DMB at 5,10 and 60 minutes.Conclusions and clinical relevance
IT and RT were not different between the groups. Both protocols provided immobilization for 30–40 minutes with excellent muscle relaxation and analgesia adequate for clinical examinations and some simple surgical procedures. 相似文献18.
Linda C. Weiland Katharina Kluge Annette P.N. Kutter Peter W. Kronen 《Veterinary anaesthesia and analgesia》2017,44(1):98-105
Objective
The aim was to compare efficacy and side effects of induction with medetomidine–ketamine or medetomidine–S(+)-ketamine by intranasal (IN) instillation in rabbits and to evaluate both protocols during subsequent isoflurane anaesthesia.Study design
Prospective, blinded, randomized experimental study in two centres.Animals
Eighty-three healthy New Zealand White rabbits undergoing tibial or ulnar osteotomy.Methods
Medetomidine (0.2 mg kg?1) with 10 mg kg?1 ketamine (MK) or 5 mg kg?1 S(+)-ketamine (MS) was administered IN to each rabbit in a randomized fashion. In Centre 1 (n = 42) rabbits were held in sternal recumbency, and in Centre 2 (n = 41) in dorsal recumbency, during drug instillation. Adverse reactions were recorded. If a rabbit swallowed during endotracheal intubation, half of the initial IN dose was repeated and intubation was re-attempted after 5 minutes. Anaesthesia was maintained with isoflurane. Heart rate, blood pressure, endtidal carbon dioxide concentration and blood gases were recorded. Data were analysed using Student's t-test, Mann–Whitney test and Fisher's exact test.Results
In all, 39 animals were assigned to the MK group and 44 to the MS group. Two rabbits in the MS group held in dorsal recumbency died after instillation of the drug. Eight (MK) and 11 rabbits (MS) were insufficiently anaesthetized and received a second IN dose. One rabbit in MK and three in MS required an isoflurane mask induction after the second IN dose. There were no significant differences between treatments for induction, intraoperative data, blood gas values and recovery data.Conclusion and clinical relevance
This study indicated that medetomidine–ketamine and medetomidine-S(+)-ketamine were effective shortly after IN delivery, but in dorsal recumbency IN administration of S(+)-ketamine led to two fatalities. Nasal haemorrhage was noted in both cases; however, the factors leading to death have not been fully elucidated. 相似文献19.
Muriel Sacks Simone K. Ringer Andrea S. Bischofberger Sabrina M. Berchtold Regula Bettschart-Wolfensberger 《Veterinary anaesthesia and analgesia》2017,44(5):1128-1138
Objective
To compare the effects of two balanced anaesthetic protocols (isoflurane–dexmedetomidine versus medetomidine) on sedation, cardiopulmonary function and recovery in horses.Study design
Prospective, blinded, randomized clinical study.Animals
Sixty healthy adult warm blood horses undergoing elective surgery.Methods
Thirty horses each were sedated with dexmedetomidine 3.5 μg kg?1 (group DEX) or medetomidine 7 μg kg?1 (group MED) intravenously. After assessing and supplementing sedation if necessary, anaesthesia was induced with ketamine/diazepam and maintained with isoflurane in oxygen/air and dexmedetomidine 1.75 μg kg?1 hour?1 or medetomidine 3.5 μg kg?1 hour?1. Ringer's lactate (7–10 mL kg?1 hour?1) and dobutamine were administered to maintain normotension. Controlled mechanical ventilation maintained end-tidal expired carbon dioxide pressures at 40–50 mmHg (5.3–6.7 kPa). Heart rate, invasive arterial blood pressure, inspired and expired gas composition and arterial blood gases were measured. Dexmedetomidine 1 μg kg?1 or medetomidine 2 μg kg?1 was administered for timed and scored recovery phase. Data were analysed using two-way repeated-measures analysis of variance and chi-square test. Significance was considered when p ≤ 0.05.Results
In group DEX, significantly more horses (n = 18) did not fulfil the sedation criteria prior to induction and received one or more supplemental doses, whereas in group MED only two horses needed one additional bolus. Median (range) total sedation doses were dexmedetomidine 4 (4–9) μg kg?1 or medetomidine 7 (7–9) μg kg?1. During general anaesthesia, cardiopulmonary parameters did not differ significantly between groups. Recovery scores in group DEX were significantly better than in group MED.Conclusions and clinical relevance
Horses administered dexmedetomidine required more than 50% of the medetomidine dose to reach equivalent sedation. During isoflurane anaesthesia, cardiopulmonary function was comparable between the two groups. Recovery scores following dexmedetomidine were better compared to medetomidine. 相似文献20.
Graeme M. Doodnaught Marina C. Evangelista Paulo V.M. Steagall 《Veterinary anaesthesia and analgesia》2017,44(2):364-369