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1.
The cardiopulmonary effects of fentanyl (4 μg/kg) or medetomidine (10 μg/kg) in saline injected epidurally were measured for 2 hours in 15 isoflurane (2.4%)-anesthetized cats. One milliliter of saline without drug was used to control for saline and volume of injection. Baseline was taken as preinjection time 0. Medetomidine significantly increased ( P < .05) mean arterial blood pressure (MAP) 5 to 20 minutes postinjection (PI) compared with baseline. MAP significantly decreased 30 to 120 minutes PI compared with baseline. Fentanyl significantly decreased MAP 5 to 120 minutes PI compared with baseline. Heart rate and respiratory rates significantly decreased in the medetomidine and fentanyl groups 5 to 120 minutes PI compared with baseline. Arterial pCO2 significantly increased while arterial pH significantly decreased 15 to 120 minutes PI in the fentanyl and medetomidine groups compared with baseline. Blood bicarbonate concentration significantly increased 90 to 120 minutes PI in the medetomidine group compared with baseline.  相似文献   

2.
BACKGROUND: Transdermal fentanyl is used clinically in horses based on pharmacokinetic data and antinociceptive effects documented in other species. HYPOTHESIS: Fentanyl IV administration increases both visceral and somatic nociceptive threshold in conscious horses. ANIMALS: Six clinically normal horses, each fitted with a permanent gastric cannula. METHODS: Visceral nociception was evaluated with 2 methods of threshold detection--olorectal distention and duodenal distention. Somatic nociception was assessed by measurement of thermal threshold. Fentanyl was administered as an increasing stepwise infusion followed by a continuous-rate infusion for a total of 2 hours. There were 4 doses of fentanyl and 1 dose each of saline and xylazine administered to each horse. Serum fentanyl concentrations were measured and the resulting data were used to determine pharmacokinetic parameters for each horse. All data were analyzed by means of a 3-factor analysis of variance followed by either a simple t test or a Bonferroni t test for multiple comparisons. RESULTS: Fentanyl administration did not result in significant changes in duodenal or colorectal distention threshold. Thermal threshold showed an increased trend at the 15-minute time point for the highest fentanyl group only, with a corresponding mean serum fentanyl concentration of 7.82 +/- 2.10 ng/mL. Two horses in this group became agitated and tachycardic during the first 15 minutes of the infusion. CONCLUSIONS AND CLINICAL IMPORTANCE: Fentanyl did not produce a significant antinociceptive effect at the doses used, 2 of which resulted in serum concentrations above the nociceptive threshold in other species.  相似文献   

3.
OBJECTIVE: To determine the effect of medetomidine on the stress response induced by ovariohysterectomy in isoflurane-anesthetized dogs. STUDY DESIGN: Prospective randomized study. ANIMALS: Twelve healthy adult female purpose-bred dogs, weighing 16.8 to 25 kg. METHODS: Two treatments were randomly administered to each of twelve dogs at weekly intervals: (1) Saline injected IM followed in 15 minutes by isoflurane anesthesia (ISO) induced by mask and maintained at an end-tidal concentration of 1.8% for 60 minutes; and (2) Medetomidine, 15 ug/lkg IM followed in 15 minutes by isoflurane anesthesia (ISO&MED) induced by mask and maintained at an end-tidal concentration of 1.0% for 60 minutes. One week after completion of these two treatments, all dogs were ovariohysterectomized. six receiving each treatment (SURG and SURG&MED). Central venous blood samples (10 mL) were obtained immediately before medetomidine or saline (baseline) and at 30, 75, and 195 minutes and 24 hours after administration of medetomidine or saline in ISO and ISO&MED. In SURG and SURG&MED, samples were obtained immediately prior to injection of medetomidine or saline (baseline) and at 30 (before skin incision), 45 (after severence of the ovarian ligament), 75 (after skin closure), 105 (30 minutes after skin closure, dog recovered and in sternal recumbency), 135, 195, 375 minutes, and 24 hours after the initial sample. Samples were analyzed for epinephrine, norepinephrine, adrenocorticotrophic hormone (ACTH), cortisol, insulin, and glucose. Data were analyzed by analysis of variance and where significant differences were found, a least significant difference test was applied. RESULTS: Premedication with medetomidine prevented or delayed the stress response induced by ovariohysterectomy in isoflurane-anesthetized dogs. CONCLUSIONS: The stress response induced by ovariohysterectomy, although significant, is of short duration. Medetomidine safely and effectively reduced surgically-induced stress responses. CLINICAL RELEVANCE: Surgically induced stress responses can be obtunded or prevented by administration of medetomidine.  相似文献   

4.
OBJECTIVE: To evaluate the effects of medetomidine and its antagonism with atipamezole in goats. STUDY DESIGN: Prospective randomized crossover study with 1 week between treatments. ANIMALS: Six healthy 3-year-old neutered goats (three male and three female) weighing 39.1-90.9 kg (60.0 +/- 18 kg, mean +/- SD). METHODS: Goats were given medetomidine (20 microg kg(-1), IV) followed, 25 minutes later, by either atipamezole (100 microg kg(-1), IV) or saline. Heart and respiratory rate, rectal temperature, indirect blood pressure, and mechanical threshold were measured, and sedation and posture were scored and blood samples obtained to measure epinephrine, norepinephrine, free fatty acids, glucose, and cortisol concentrations at baseline (immediately before medetomidine), 5 and 25 minutes after medetomidine administration, and at 5, 30, 60, and 120 minutes after the administration of antagonist or saline. Parametric and nonparametric tests were used to evaluate data; p < 0.05 was considered significant. RESULTS: Medetomidine decreased body temperature, heart rate, and respiratory rate and increased mean arterial blood pressure, cortisol, and glucose. Recumbency occurred 89 +/- 50 seconds after medetomidine administration. All goats were standing 86 +/- 24 seconds after atipamezole administration whereas all goats administered saline were sedate and recumbent at 2 hours. Tolerance to compression of the withers and metacarpus increased with medetomidine. From 5 to 120 minutes after saline or atipamezole administration, there were differences in body temperature, glucose, and cortisol but none in heart rate or blood pressure. Three of the six goats receiving saline developed bloat; five of six urinated. After atipamezole, four of six goats developed piloerection and all goats were agitated and vocalized. CONCLUSION: At the doses used, atipamezole antagonized the effects of medetomidine on recumbency, sedation, mechanical threshold, and the increase in glucose. Atipamezole increased the rate of return of cortisol toward baseline, and prevented further decline in rectal body temperature. CLINICAL RELEVANCE: Atipamezole may be used to antagonize some, but not all effects of medetomidine.  相似文献   

5.
OBJECTIVE: To examine stress-related neurohormonal and metabolic effects of butorphanol, fentanyl, and ketamine administration alone and in combination with medetomidine in dogs. ANIMALS: 10 Beagles. PROCEDURE: 5 dogs received either butorphanol (0.1 mg/kg), fentanyl (0.01 mg/kg), or ketamine (10 mg/kg) IM in a crossover design. Another 5 dogs received either medetomidine (0.02 mg/kg) and butorphanol (0.1 mg/kg), medetomidine and fentanyl (0.01 mg/kg), medetomidine and ketamine (10 mg/kg), or medetomidine and saline (0.9% NaCI) solution (0.1 mL/kg) in a similar design. Blood samples were obtained for 6 hours following the treatments. Norepinephrine, epinephrine, cortisol, glucose, insulin, and nonesterified fatty acid concentrations were determined in plasma. RESULTS: Administration of butorphanol, fentanyl, and ketamine caused neurohormonal and metabolic changes similar to stress, including increased plasma epinephrine, cortisol, and glucose concentrations. The hyperglycemic effect of butorphanol was not significant. Ketamine caused increased norepinephrine concentration. Epinephrine concentration was correlated with glucose concentration in the butorphanol and fentanyl groups but not in the ketamine groups, suggesting an important difference between the mechanisms of the hyperglycemic effects of these drugs. Medetomidine prevented most of these effects except for hyperglycemia. Plasma glucose concentrations were lower in the combined sedation groups than in the medetomidine-saline solution group. CONCLUSIONS AND CLINICAL RELEVANCE: Opioids or ketamine used alone may cause changes in stress-related biochemical variables in plasma. Medetomidine prevented or blunted these changes. Combined sedation provided better hormonal and metabolic stability than either component alone. We recommend using medetomidine-butorphanol or medetomidine-ketamine combinations for sedation or anesthesia of systemically healthy dogs.  相似文献   

6.
ObjectiveTo describe the pharmacodynamics and pharmacokinetics following an intravenous (IV) bolus dose of medetomidine in the horse.Study designProspective experimental trial.AnimalsEight, mature healthy horses age 11.7 ± 4.6 (mean ± SD) years, weighing 557 ± 54 kg.MethodsMedetomidine (10 μg kg?1) was administered IV. Blood was sampled at fixed time points from before drug administration to 48 hours post administration. Behavioral, physiological and biochemical data were obtained at predetermined time points from 0 minutes to 24 hours post administration. An algometer was also used to measure threshold responses to noxious stimuli. Medetomidine concentrations were determined by liquid chromatography-Mass Spectrometry and used for calculation of pharmacokinetic parameters using noncompartmental and compartmental analysis.ResultsPharmacokinetic analysis estimated that medetomidine peaked (8.86 ± 3.87 ng mL?1) at 6.4 ± 2.7 minutes following administration and was last detected at 165 ± 77 minutes post administration. Medetomidine had a clearance of 39.6 ± 14.6 mL kg?1 minute?1 and a volume of distribution of 1854 ± 565 mL kg?1. The elimination half-life was 29.1 ± 12.5 minutes. Glucose concentration reached a maximum of 176 ± 46 mg dL?1 approximately 1 hour post administration. Decreased heart rate, respiratory rate, borborygmi, packed cell volume, and total protein concentration were observed following administration. Horses lowered their heads from 107 ± 12 to 20 ± 10 cm within 10 minutes of drug administration and gradually returned to normal. Horse mobility decreased after drug administration. An increased mechanical threshold was present from 10 to 45 minutes and horses were less responsive to sound.Conclusion and clinical relevance Behavioral and physiological effects following intravenous administration positively correlate with pharmacokinetic profiles from plasma medetomidine concentrations. Glucose concentration gradually transiently increased following medetomidine administration. The analgesic effect of the drug appeared to have a very short duration.  相似文献   

7.
Data allowing rational use of analgesics in cats are limited. Pharmacokinetics and pharmacodynamics of fentanyl were studied in cats. Plasma fentanyl concentrations were measured using radioimmunoassay in a crossover study in six cats after 10 microg/kg (i.v.) or by application of fentanyl in pluronic lecithin organogel (PLO) to the inner ear pinna. On a separate occasion thermal thresholds were measured after i.v. fentanyl (10 microg/kg) or saline. Plasma fentanyl concentrations reached 4.7-8.31 ng/mL 2 min after i.v. administration and were undetectable after 95 min. Fentanyl was not detected in plasma at any time after PLO use. Thermal thresholds did not change following saline administration but were increased above baseline from 5 to 110 min after i.v. fentanyl. In this model a plasma concentration of >1.07 ng/mL was required to provide analgesia. Plasma concentrations were measured in additional cats after intranasal or oral dosing (2 microg/kg) and after 30 microg/kg in PLO gel. After oral and nasal dosing, Cmax values were 0.96 and 1.48 ng/mL at 5 and 2 min, respectively. Plasma fentanyl was not detected after application of the higher dose of fentanyl in PLO.  相似文献   

8.
Medetomidine is the most potent and selective alpha2-agonist used in veterinary medicine and its effects can be antagonized by the alpha2-antagonist atipamezole. The pharmacokinetics of medetomidine and atipamezole were studied in a cross-over trial in eight lactating dairy cows. The animals were injected intravenously (i.v.) with medetomidine (40 microg/kg) followed by atipamezole i.v. (200 microg/kg) or saline i.v. after 60 min. Drug concentrations in plasma were measured by HPLC. After the injection of atipamezole, the concentration of medetomidine in plasma increased slightly, the mean increment being 2.7 ng/mL and the mean duration 12.1 min. However, atipamezole did not alter the pharmacokinetics of medetomidine. It is likely that the increase in medetomidine concentration is caused by displacement of medetomidine by atipamezole in highly perfused tissues. The volume of distribution at steady state (Vss) for medetomidine followed by saline and medetomidine followed by atipamezole was 1.21 and 1.32 L/kg, respectively, whereas the total clearance (Cl) values were 24.2 and 25.8 mL/min x kg. Vss and Cl values for atipamezole were 1.77 mL/kg and 48.1 mL/min x kg, respectively. Clinically, medetomidine significantly reduced heart rate and increased rectal temperature for 45 min. Atipamezole reversed the sedative effects of medetomidine. However, all the animals, except one, relapsed into sedation at an average of 80 min after injection of the antagonist.  相似文献   

9.
OBJECTIVE: To evaluate the analgesic effects of medetomidine (MED) and butorphanol (BTO) in cats after ovariohysterectomy. STUDY DESIGN: A placebo-controlled, blinded monocenter clinical study. ANIMALS: Healthy adult female client-owned cats. METHODS: Sixty-four cats weighing 3.15 +/- 0.6 kg, presented to the University of Helsinki's Small Animal Teaching Hospital for routine elective ovariohysterectomy, received MED at 15 microg/kg (n = 18), BTO at 0.1 mg/kg (n = 23), or saline (PL) (n = 23) intramuscularly immediately after ovariohysterectomy. Level of pain perception, degree of restlessness, and extent of sedation were scored subjectively before and at 30, 60, 90, and 120 minutes after test-drug administration. RESULTS: BTO provided the best pain relief, followed by MED. Saline provided the least pain relief. Both MED and BTO effectively and identically prevented postoperative restlessness. MED and BTO produced an identical degree of sedation that was better than the PL. CONCLUSIONS: Both MED (at 15 microg/kg) and BTO (at 0.1 mg/kg) prevent postoperative pain in cats after ovariohysterectomy. Clinical Relevance-MED and BTO are useful for preventing postoperative pain in cats.  相似文献   

10.
The pharmacokinetics of medetomidine hydrochloride (Domitor) administered at a single dose of 15 μg/kg IV in sheep are described. Plasma medetomidine concentrations were determined using a sensitive radioreceptor assay technique, capable of also measuring metabolites which would bind to α2 adrenergic receptors. Medetomidine was rapidly distributed, with a half-life of distribution of 4.65/pm0.65 min. The apparent volume of distribution was 2.69/pm0.62 L/kg, while elimination half-life was 37.85/pm2.84 min. Total body clearance varied between 16.29 and 151.81 mL/min.kg. Pharmacological effects of medetomidine paralleled its plasma concentration.  相似文献   

11.
OBJECTIVE: To evaluate the effects of medetomidine on dynamic left ventricular outflow tract (LVOT) obstruction in cats with left ventricular hypertrophy. DESIGN: Clinical trial. ANIMALS: 6 domestic shorthair cats with echocardiographic evidence of dynamic LVOT obstruction. PROCEDURE: Cats were restrained in lateral recumbency, and baseline M-mode and Doppler echocardiographic examinations were performed. An ECG was recorded continuously, and blood pressure was measured indirectly with Doppler instrumentation. Medetomidine (20 microg/kg 19.1 microg/lb]) was then administered i.m., and examinations were repeated 15 minutes later. RESULTS: Significant decreases in heart rate, LVOT velocity, and the LVOT pressure gradient were documented following medetomidine administration. After adjusting for the effects of heart rate by ANCOVA, there were no significant differences in any other systolic or diastolic indices of left ventricular function. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that administration of medetomidine to cats with dynamic LVOT obstruction may result in elimination of outflow tract obstruction; medetomidine may be a suitable sedative and analgesic agent in this subpopulation of cats.  相似文献   

12.
OBJECTIVE: To compare the sensory and motor effects of adding medetomidine to mepivicaine, administered either perineurally or systemically, for radial nerve block in dogs. STUDY DESIGN: Prospective randomized cross-over study. ANIMALS: Six healthy Beagles, aged 18.7 +/- 6.3 months and weighing 10.4 +/- 1.3 kg. METHODS: Dogs were anesthetized briefly with sevoflurane on three separate occasions and received each treatment administered in random order: mepivacaine 5 mg kg(-1) perineurally around the radial nerve with saline 0.01 mL kg(-1) intramuscularly (CONTROL); mepivacaine 5 mg kg(-1) and medetomidine 0.01 mg kg(-1) combined, perineurally with saline 0.01 mL kg(-1) intramuscularly (MEDPN); mepivacaine 5 mg kg(-1) perineurally around the radial nerve with medetomidine 0.01 mg kg(-1) intramuscularly (MEDIM). All nerve blocks were performed with the aid of a nerve locator. Motor effects were evaluated based on the ability to bear weight. Sensory effects were evaluated by the response to a graded-electrical stimulus. These were evaluated at 5-minute intervals for the first hour, and at 10-minute intervals thereafter. Mean intervals were calculated as follows: time to motor block onset, duration of motor block, time to peak sensory block, duration of peak sensory block (i.e. period of no response to maximal stimulus intensity), and duration of residual sensory block (i.e. time to return to baseline sensory function). Treatment means were compared using a one-way analysis of variance for repeated measures and, where significant differences were noted, a Student-Newman-Keuls test was applied; p < 0.05 was considered significant. RESULTS: Medetomidine, administered either systemically or perineurally, significantly prolonged duration of peak motor block, peak sensory block, and residual sensory block compared with CONTROL. CONCLUSION: Medetomidine prolonged sensory and motor blockade after radial nerve block with mepivacaine in dogs. CLINICAL RELEVANCE: Medetomidine may prove to be a useful adjunct to peripheral nerve blockade with local anesthetics.  相似文献   

13.
OBJECTIVE: To determine the cardiorespiratory effects of an i.v. infusion of propofol alone or in association with fentanyl, alfentanil, or sufentanil in cats and, for each combination, the minimal infusion rate of propofol that would inhibit a response to noxious stimuli. DESIGN: Randomized crossover study. ANIMALS: 6 cats. PROCEDURE: Cats were anesthetized 4 times in random order. After i.v. administration of fentanyl, alfentanil, sufentanil, or saline (0.9% NaCl) solution, anesthesia was induced with propofol (7 mg/kg 13.2 mg/lb], i.v.) and maintained for 90 minutes with a continuous infusion of propofol in conjunction with fentanyl (0.1 microg/kg/min [0.045 microg/lb/min]), alfentanil (0.5 microg/kg/min [0.23 microg/lb/min]), sufentanil (0.01 microg/kg/min [0.004 microg/lb/min]), or saline solution (0.08 mL/kg/min [0.036 mL/lb/min]). RESULTS: Minimal infusion rate of propofol required to prevent a response to a noxious stimulus was higher when cats received saline solution. After 70 minutes, minimal infusion rate of propofol was significantly higher with fentanyl than with sufentanil. Decreases in heart rate, systolic blood pressure, rectal temperature, and respiratory rate were detected with all treatments. Oxygen saturation did not change significantly, but end-tidal partial pressure of carbon dioxide increased with all treatments. There were no significant differences in recovery times or sedation and recovery scores among treatments. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that infusion of propofol in combination with fentanyl, alfentanil, or sufentanil results in satisfactory anesthesia in cats.  相似文献   

14.
Medetomidine, a novel alpha 2-agonist drug intended for small animal sedation, was injected intramuscularly at dose rates of 0.02, 0.06 and 0.18 mg/kg. Xylazine (3.0 mg/kg) and saline were used for comparison. The five treatments were tested in a Latin square design in five cats. Treatments differed significantly in three-way analysis of variance, medetomidine inducing an increase in drowsiness with a corresponding decrease in both aroused waking and sleep determined by polygraphical criteria. The duration of effect was dose-dependent. The effect of 0.18 mg/kg medetomidine was comparable to 3.0 mg/kg of xylazine. The drugs also induced bradycardia.  相似文献   

15.
The efficacy of atipamezole to reverse medetomidine induced effects in cats was investigated in a clinical study (n=160) including placebo. The atipamezole doses (intramuscularly) were two, four and six times (2X, 4X and 6X) the preceding medetomidine dose, which was 100 ug/kg body weight intramuscularly. Medetomidine was shown to produce moderate to deep sedation, recumbency and bradycardia in cat. Atipamezole was clearly able to reverse these effects of medetomidine. The median arousal time in the atipamezole dose groups was five minutes and walking time, 10 minutes, compared with more than 30 minutes in the placebo group. Heart rate was increased towards normal by atipamezole in a dose related manner. The clinical evaluation of the ability of atipamezole to reverse the effects of medetomidine was found to be ‘good’ in 82-5, 75 or 65 per cent of cases in dose groups 2X, 4X and 6X, respectively. The effect of atipamezole was evaluated as being ‘too potent’ in 2–5, 5 or 25 per cent of the cases in these respective groups. The incidence of side effects was negligible. In conclusion, atipamezole at the dose of two to four times the preceding dose of medetomidine seems to be an effective medetomidine antagonist for clinical use in cats.  相似文献   

16.
The role of ketamine (K) in pain management is controversial. It is reported to provide visceral analgesia in cats. This study aimed to assess its somatic actions using a thermal threshold (TT) model. Six cats (four spayed females, two castrated males, 4.3–7.2 kg) participated in the study. The day before each study, the thorax of each of the cats was shaved and a cephalic catheter was placed. TT was measured using a device specifically developed for cats. A heater element and temperature sensor housed in a small probe were held against the thorax of the cats with an elastic band and pressure bladder to assure consistent contact. The skin temperature was recorded before each test, then the heater was activated. When the cat responded by flinching, turning, or jumping, the stimulus was terminated and the threshold temperature was recorded. Treatments were 2 mg kg?1 of K (10 mg mL?1), or 0.2 mL kg?1 of saline (S) IV, given in a randomized cross‐over design with at least 1 week between treatments. The investigator was blinded to the treatment. TT was measured thrice before treatment (baseline threshold) at 15 minutes, then every 30 minutes for 8 hours and once at 24 hours after injection. Data were analyzed using a four‐factor anova . Cats were sedated for 45 minutes following K treatment. There was no difference in baseline TT between treatments (K = 41.9 ± 1.7 °C, S = 41.0 ± 1.45 °C), and no change in TT at any time in the S group. TT increased significantly at 15 and 30 minutes after K, then decreased below baseline values between 210 and 390 minutes, with a nadir of 38.8 ± ± 1.05 °C at 390 minutes. During this time period, cats exhibited normal activity, but responses to thermal stimuli were exaggerated. This study suggested that K caused a delayed onset hyperalgesia in cats.  相似文献   

17.
OBJECTIVE: To assess duration of actions of butorphanol, medetomidine, and a butorphanol-medetomidine combination in dogs given subanesthetic doses of isoflurane (ISO). ANIMALS: 6 healthy dogs. PROCEDURE: Minimum alveolar concentration (MAC) values for ISO were determined. for each dog. Subsequently, 4 treatments were administered to each dog (saline [0.9% NaCl] solution, butorphanol [0.2 mg/kg of body weight], medetomidine [5.0 microg/kg], and a combination of butorphanol [0.2 mg/kg] and medetomidine [5.0 microg/kg]). All treatments were administered IM to dogs concurrent with isoflurane; treatment order was determined, using a randomized crossover design. Treatments were given at 7-day intervals. After mask induction with ISO and instrumentation with a rectal temperature probe, end-tidal CO2 and anesthetic gas concentrations were analyzed. End-tidal ISO concentration was reduced to 90% MAC for each dog. A tail clamp was applied 15 minutes later. After a positive response, 1 of the treatments was administered. Response to application of the tail clamp was assessed at 15-minute intervals until a positive response again was detected. RESULTS: Duration of nonresponse after administration of saline solution, butorphanol, medetomidine, and butorphanol-medetomidine (mean +/- SD) was 0.0+/-0.0, 1.5+/-1.5, 2.63+/-0.49, and 5.58+/-2.28 hours, respectively. Medetomidine effects were evident significantly longer than those for saline solution, whereas effects for butorphanol-medetomidine were evident significantly longer than for each agent administered alone. CONCLUSION AND CLINICAL RELEVANCE: During ISO-induced anesthesia, administration of medetomidine, but not butorphanol, provides longer and more consistent analgesia than does saline solution, and the combination of butorphanol-medetomidine appears superior to the use of medetomidine or butorphanol alone.  相似文献   

18.
This study was carried out in order to evaluate the analgesic, sedative, immobilizing and cardiopulmonary effects of medetomidine in goats after lumbosacral epidural injection of three (10, 20 and 30 micrograms/kg body weight) doses. The volume of the injection for all three medetomidine doses was 5 ml in sterile water. Seventeen clinically healthy, Small East African goats of either sex and weighing between 12 and 22 kg (mean +/- SD; 14.8 +/- 2.5 kg body weight) were used. The animals were randomly assigned to two groups. Seven goats were used for evaluating analgesic, behavioural and cardiopulmonary effects while 10 were used for experimental surgery. The cardiopulmonary values and rectal temperature were determined and recorded at time 0 (preinjection) and at 5, 10, 15, 20 and 30 min, and thereafter at 15-min intervals up to 180 min after injection. Analgesia of the flank and perineum was determined at time 0 (preinjection) and at 5, 10, 15, 30, 60, 120 and 180 min using a scoring system. The spread of analgesia to the thorax, neck, forelimbs and head was also determined and recorded. The onset and duration of lateral recumbency was noted and recorded. Medetomidine at the given doses induced variable cardiopulmonary depression, which was not detrimental to the animals. All three doses (10, 20 and 30 micrograms/kg) of medetomidine induced adequate analgesia of the flank and perineum. Analgesia extended to the thorax, forelimbs, neck and head. The duration of lateral recumbency was 136 and 166 min for the 20 and 30 micrograms/kg medetomidine doses, respectively. The duration of lateral recumbency was not determined for the animal given 10 micrograms/kg medetomidine. Signs of sedation (lowering of the head, drooping of the lower lip, partial to complete closure of the eyes and salivation) were noted after administration of all three doses. It can be concluded from this study that all three doses induced adequate analgesia of the flank and perineum. Surgical analgesia of the flank of goats was achieved after lumbosacral epidural administration of 20 micrograms medetomidine/kg, diluted in 5 ml of sterile water. Surgery was not performed with the other doses (10 and 30 micrograms/kg) of medetomidine.  相似文献   

19.
O bjectives : The objective of this study was to investigate medetomidine-buprenorphine preanaesthetic medication in cats.
M ethods : Forty American Society of Anesthesiologists (ASA) I female cats were enrolled in this prospective, blinded, clinical study. Cats were randomised into one of four groups: group M30 were injected intramuscularly with 30 μg/kg medetomidine, groups M10+B, M30+B and M50+B received 10, 30 and 50 μg/kg of medetomidine, respectively, each in combination with 20 μg/kg buprenorphine. After 30 minutes, a sedation score was allocated. Anaesthesia was induced using intravenous propofol and maintained using isoflurane in oxygen, while cats underwent ovariohysterectomy. Heart rate, respiratory rate, end-tidal carbon dioxide tension and oxygen saturation of haemoglobin were recorded. Atipamezole was administered intramuscularly at volatile agent discontinuation. Time taken to lift their head, sit in sternal and stand were recorded along with quality of recovery.
R esults : M30+B cats required significantly less isoflurane compared with M30 cats. Heart rate and oxygen saturation of haemoglobin were significantly lower in M50+B cats than in M30 cats. All M+B groups experienced significantly better recoveries compared with the medetomidine only M30 control group.
C linical S ignificance : The addition of buprenorphine to medetomidine preanaesthetic medication in cats reduces volatile agent vaporiser setting and improves the quality of recovery from anaesthesia.  相似文献   

20.
ObjectiveTo measure cutaneous electrical nociceptive thresholds in relation to known thermal and mechanical stimulation for nociceptive threshold detection in cats.Study designProspective, blinded, randomized cross-over study with 1-week washout interval.AnimalsEight adult cats [bodyweight 5.1 ± 1.8 kg (mean + SD)].MethodsMechanical nociceptive thresholds were tested using a step-wise manual inflation of a modified blood pressure bladder attached to the cat’s thoracic limb. Thermal nociceptive thresholds were measured by increasing the temperature of a probe placed on the thorax. The electrical nociceptive threshold was tested using an escalating current from a constant current generator passed between electrodes placed on the thoracic region. A positive response (threshold) was recorded when cats displayed any or all of the following behaviors: leg shake, head turn, avoidance, or vocalization. Four baseline readings were performed before intramuscular injection of meperidine (5 mg kg−1) or an equal volume of saline. Threshold recordings with each modality were made at 15, 30, 45, 60, 90, and 120 minutes post-injection. Data were analyzed using anova and paired t-tests (significance at p < 0.05).ResultsThere were no significant changes in thermal, mechanical, or electrical thresholds after saline. Thermal thresholds increased at 15–60 minutes (p < 0.01) and mechanical threshold increased at 30 and 45 minutes after meperidine (p < 0.05). Maximum thermal threshold was +4.1 ± 0.3 °C above baseline at 15 minutes while maximum mechanical threshold was 296 ± 265 mmHg above baseline at 30 minutes after meperidine. Electrical thresholds following meperidine were not significantly different than baseline (p > 0.05). Thermal and electrical thresholds after meperidine were significantly higher than saline at 30 and 45 minutes (p < 0.05), and at 120 minutes (p < 0.05), respectively. Mechanical thresholds were significantly higher than saline treatment at 30 minutes (p ≤ 0.05).Conclusion and clinical relevanceElectrical stimulation did not detect meperidine analgesia whereas both thermal and mechanical thresholds changed after meperidine administration in cats.  相似文献   

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