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1.
Sixteen captive and wild-caught American alligators (Alligator mississippiensis), seven juveniles (< or = 1 m total length [TL]; 6.75 +/- 1.02 kg), and nine adults (> or = 2 m TL; 36.65 +/- 38.85 kg), were successfully anesthetized multiple times (n = 33) with an intramuscular (i.m.) medetomidine-ketamine (MK) combination administered in either the triceps or masseter muscle. The juvenile animals required significantly larger doses of medetomidine (x = 220.1 +/- 76.9 microg/kg i.m.) and atipamezole (x = 1,188.5 -/+ 328.1 microg/kg i.m.) compared with the adults (medetomidine, x = 131.1 +/- 19.5 microg/kg i.m.; atipamezole, x = 694.0 +/- 101.0 microg/kg i.m.). Juvenile alligators also required higher (statistically insignificant) doses of ketamine (x = 10.0 +/- 4.9 mg/kg i.m.) compared with the adult animals (x = 7.5 +/- 4.2 mg/kg i.m.). The differences in anesthesia induction times (juveniles, x = 19.6 +/- 8.5 min; adults, x = 26.6 +/- 17.4 min) and recovery times (juveniles, x = 35.4 +/- 22.1 min; adults, x = 37.9 +/- 20.2 min) were also not statistically significant. Anesthesia depth was judged by the loss of the righting, biting, corneal and blink, and front or rear toe-pinch withdrawal reflexes. Recovery in the animals was measured by the return of reflexes, open-mouthed hissing, and attempts to high-walk to the opposite end of the pen. Baseline heart rates (HRs) were significantly higher in the juvenile animals (x = 37 +/- 4 beats/min) compared with the adults (x = 24 +/- 5 bpm). However, RRs (juveniles, x = 8 +/- 2 breaths/min; adults, x = 8 +/- 2 breaths/min) and body temperatures (juveniles, x = 24.1 +/- 1.1 degrees C; adults, x = 25.2 +/- 1.2 degrees C) did not differ between the age groups. In both groups, significant HR decreases were recorded within 30-60 min after MK administration. Cardiac arrhythmias (second degree atrio-ventricular block and premature ventricular contractions) were seen in two animals but were not considered life-threatening. Total anesthesia times ranged from 61-250 min after i.m. injection. Although dosages were significantly different between the age groups, MK and atipamezole provided safe, effective, completely reversible anesthesia in alligators. Drug-dosage differences appear to be related to metabolic differences between the two size-classes, requiring more research into metabolic scaling as a method of calculating anesthetic dosages.  相似文献   

2.
The objective of this project was to evaluate the acid-base, blood gas, and physiologic parameters of white-tailed deer (Odocoileus virginianus) during laparoscopy in the head-down position. Eleven white-tailed does were captured and then immobilized with xylazine (6 mg/kg i.m.) and ketamine (7 mg/kg i.m.). The deer were intubated orotracheally and maintained with isoflurane in oxygen. The deer were positioned in dorsal recumbency and positive pressure ventilated. Heart rate (HR), arterial blood pressure, end-tidal carbon dioxide concentration (FE/CO2), and CO2 insufflation pressure were recorded every 5 min. Respiratory parameters, plasma electrolytes, and peak inspiratory pressure were measured immediately before tilting deer in the head-down position (45-55 degrees), 5 min after tilting, and immediately before the end of the procedure (while tilted). Butorphanol (0.05 mg/kg i.m.) was administered at the end of the procedure and yohimbine (0.2 mg/kg i.v.) administered before release. The deer weighed 52 kg (28-70 kg) [median (minimum-maximum)]. The peak inspiratory pressure in dorsal recumbency while still horizontal was 25 cm H2O (16-28 cm H2O), which increased to 29 cm H2O (18-46 cm H2O) after tilting (P = 0.02). PaO2, PaCO2, FE/CO2, and pH did not change after tilting in the head-down position or after insufflation. HR did not change during the anesthetic period. Mean arterial pressure did not change after tilting or abdominal insufflation, but decreased by the end of the anesthetic period (approximately 1 hr). Time from intubation to extubation was 117 min (72-170 min) (n = 5) and surgery time was 31 min (17-60 min; n = 10). We conclude that captured white-tailed deer have minimal derangements to acid-base, blood gas, or physiologic parameters during laparoscopy in the head-down position with abdominal insufflation, and thus this procedure may be performed safely in ventilated white-tailed deer.  相似文献   

3.
With the use of a crossover study design, we investigated the respiratory and cardiovascular effects of naloxone administration in eight healthy Rocky Mountain wapiti (Cervus elaphus nelsoni) anesthetized with carfentanil (10 microg/kg i.m.) and xylazine (0.1 mg/kg). Anesthetized animals showed profound hypoxemia with mild hypercapnia, tachycardia, hypertension, and acidosis prior to naloxone administration. After monitoring equipment was placed, animals were administered either naloxone (2 microg/microg carfentanil i.v.) or an equivalent volume of normal saline. Mean values for PaO2, PaCO2, heart rate, and respiratory rate were significantly different between naloxone- and saline-treated groups, but mean blood pressure, hematocrit, and serum electrolyte concentrations were not. Mean PaO2 was 23.0 +/- 4.1 mm Hg prior to administration of naloxone or saline and increased to 50.2 +/- 7.3 mm Hg after naloxone administration. Mean PaO2 of saline-treated animals did not change significantly. Electrocardiograms of three saline-treated animals suggested myocardial hypoxia. Hypoxemia appeared to be caused by respiratory depression, hemodynamic alterations, and lateral recumbency. All but one animal remained anesthetized after naloxone administration. Anesthesia in all animals was reversed in < or = 4 min with naltrexone (100 mg/mg carfentanil i.v. s.c.) and yohimbine (0.1 mg/kg i.v.). One bolus of naloxone improved oxygenation in carfentanil-xylazine-anesthetized wapiti.  相似文献   

4.
OBJECTIVE: To determine sedative and cardiorespiratory effects of romifidine alone and romifidine in combination with butorphanol and effects of preemptive atropine administration in cats sedated with romifidine-butorphanol. DESIGN: Randomized crossover study. ANIMALS: 6 healthy adult cats. PROCEDURES: Cats were given saline (0.9% NaCl) solution followed by romifidine alone (100 microg/kg [45.4 microg/lb], i.m.), saline solution followed by a combination of romifidine (40 microg/kg [18.1 microg/lb], i.m.) and butorphanol (0.2 mg/kg [0.09 mg/lb], i.m.), or atropine (0.04 mg/kg [0.02 mg/lb], s.c.) followed by romifidine (40 microg/kg, i.m.) and butorphanol (0.2 mg/kg, i.m.). Treatments were administered in random order, with > or = 1 week between treatments. Physiologic variables were determined before and after drug administration. Time to recumbency, duration of recumbency, time to recover from sedation, and subjective evaluation of sedation, muscle relaxation, and analgesia were assessed. RESULTS: Bradycardia developed in all cats that received saline solution and romifidine-butorphanol or romifidine alone. Preemptive administration of atropine prevented bradycardia for 50 minutes in cats given romifidine-butorphanol. Oxyhemoglobin saturation was significantly decreased 10 minutes after romifidine-butorphanol administration in atropine-treated cats. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that administration of romifidine alone or romifidine-butorphanol causes a significant decrease in heart rate and that preemptive administration of atropine in cats sedated with romifidine-butorphanol effectively prevents bradycardia for 50 minutes.  相似文献   

5.
The pharmacokinetics of the biliary elimination of oxytetracycline (OTC) and tissue concentrations in certain organs were studied in 10 Leghorn hens. The animals were anaesthetized using xylazine/ketamine administered by the intramuscular (i.m.) route and were immobilized for right laparotomy. Both bile ducts were cannulated and a dose of 20 mg/kg of oxytetracycline hydrochloride was administered intravenously (i.v.). Samples of bile excreted were taken at predetermined intervals during 6 h. At 6 h animals were slaughtered and tissue samples of blood, liver, kidney, pancreas, spleen, heart, lung and pectoral muscle were taken. The values for OTC biliary elimination rate times were best fitted to a one-exponential equation. The maximum value for OTC biliary excretion rate (3.69+/-0.6 microg/min/kg) was reached at approximately 17.5 min (time to maximum concentration (tmax)). The first-order rate constant for the biliary excretion (k) and the half-life (t1/2) were 6.7x10(-3) min(-1) and 110.55 min, respectively. The mean value of area under the biliary excretion rate time curve (AUC) indicated that 839.77 microg/kg body weight (b.w.) were eliminated by the biliary route. The cumulative biliary excretion data indicated that approximately 4.20% of the dose was eliminated by this route, 3.28% being eliminated during the first 6 h and 0.92% thereafter. The highest mean concentrations were found in the kidney (35.82 microg/kg) and liver (16.77 microg/g). Significant differences were found between the concentrations of the various tissues studied. Plasma concentration was lower than that of the other tissues (except lung).  相似文献   

6.
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   

7.
Carfentanil citrate was given orally to five adult brown bears (Ursus arctos) on 14 separate occasions during the winter and summer to determine effective anesthetic dosages and how season may alter these dosages. Lower blood urea nitrogen:creatinine ratios, depressed appetite, and decreased activity levels in the winter versus summer were reflective of different metabolic states, even though bears were not hibernating in the winter. Doses of carfentanil citrate between 6.0 and 15.2 microg/kg were mixed with 5-10 ml of honey, which the bears licked voluntarily from a spoon. During each anesthetization, respiratory and heart rates, hemoglobin saturation, temperature, electrocardiogram, blood gas values, and level of consciousness were monitored and utilized to determine effective dosages. Mean (+/- SE) dose requirements in the winter were 7.6 +/- 0.4 microg/kg, whereas a greater mean dose of 12.7 +/- 0.5 microg/kg was required in the summer (P < 0.05). After ingestion began, sternal recumbency occurred in an average of 7.5 min (range: 4-11 min), and full restraint and safe handling was achieved in 21 min (range: 8-40 min). At the end of each procedure, naltrexone was given as the reversal agent at a ratio of 100 mg naltrexone per 1 mg carfentanil, with 25% of the dose given i.v. or i.m. and 75% given s.c. Mean reversal time was 6 min after injection of naltrexone (range: 4-9 min). Rapid induction and recovery times and ease of oral administration make carfentanil citrate an effective anesthetic agent for use in brown bears. However, hypoventilation and respiratory acidosis were noted in all bears, and oxygen insufflation is recommended.  相似文献   

8.
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   

9.
The pharmacokinetics and intramuscular (i.m.) bioavailability of cefoperazone and cefamandole (20mg/kg) were investigated in dogs and the findings related to minimal inhibitory concentrations (MICs) for 90 bacterial strains isolated clinically from dogs. The MICs of cefamandole for Staphylococcus intermedius (MIC(90) 0.125 microg/mL) were lower than those of cefoperazone (MIC(90) 0.5 micro/mL) although the latter was more effective against Escherichia coli strains (MIC(90) 2.0 microg/mL vs. 4.0 microg/mL). The pharmacokinetics of the drugs after intravenous administrations were similar: a rapid distribution phase was followed by a slower elimination phase (t((1/2)lambda2) 84.0+/-21.3 min for cefoperazone and 81.4+/-9.7 min for cefamandole). The apparent volume of distribution and body clearance were 0.233 L/kg and 1.96 mL/kg/min for cefoperazone, 0.190 L/kg and 1.76 mL/kg/min for cefamandole. After i.m. administration the bioavailability and peak serum concentration of cefamandole (85.1+/-13.5% and 35.9+/-5.4 microg/mL) were significantly higher than cefoperazone (41.4+/-7.1% and 24.5+/-3.0 micog/mL), but not the serum half-lives (t(1/2el) 134.3+/-12.6 min for cefoperazone and 145.4+/-12.3 min for cefamandole). The time above MIC(90) indicated that cefamandole can be administered once daily to dogs for the treatment of staphylococcal infections (T>MIC for S. intermedius 23.8+/-0.3 and for Staphylococcus aureus 21.6+/-0.6h).  相似文献   

10.
The cardiopulmonary effects of three drug combinations in polar bears (Ursus maritimus) were studied. In 1995, five adult polar bears received i.m. injections of either 8.2 +/- 1.3 mg/kg of Telazol or a combination of 159 +/- 34 microg/kg of medetomidine with 4 +/- 0.8 mg/kg of ketamine in a crossover design. Significantly higher mean arterial pressure, lower heart rate, and lower partial pressure of arterial oxygen (Pao2) occurred with medetomidine-ketamine. In 1996, six adult polar bears were immobilized with i.m. injections of either 8.2 +/- 2 mg/kg of zolazepam-tiletamine or a combination of 74.8 +/- 11.8 microg/kg of medetomidine plus 2.2 +/- 0.3 mg/kg of zolazepam-tiletamine in a crossover design. Significantly higher mean arterial pressure and lower heart rate, base excess, and Pao2 occurred with medetomidine-zolazepam-tiletamine compared with zolazepam-tiletamine alone. Hypertension, bradycardia, and decreased Pao2 were observed with both medetomidine-ketamine and medetomidine-zolazepam-tiletamine. Both combinations should be well tolerated by healthy bears, but both have the potential to produce adverse effects in animals with cardiopulmonary disease. Zolazepam-tiletamine produced minimal adverse cardiopulmonary effects, consistent with the wide margin of safety of this combination in bears. The analgesic effect of zolazepam-tiletamine was apparently poor on the basis of the marked increases in pulse rate and mean arterial pressure after noxious stimuli.  相似文献   

11.
Nine Grevy's zebras (Equus grevyi) and three Burchell's zebras (Equus burchellii) were immobilized in a standing position a total of 70 times for minor, nonpainful procedures over a 9-yr period. Standing sedation was successfully obtained with a combination of detomidine and butorphanol on 47 occasions (67.1%). Detomidine i.m. (median 0.10 mg/kg; range: 0.07-0.21) was administered by dart, followed 10 min later by butorphanol i.m. (median 0.13 mg/kg; range 0.04-0.24). The dosages were varied depending on the initial demeanor of the animal. On 23 occasions (32.9%), small amounts of etorphine (median 2.5 microg/kg; range 1.1-12.3 microg/kg) plus acepromazine (median 10 microg/kg; range 4.4-50 microg/kg) (as in Large Animal-Immobilon) had to be administered i.m. to gain sufficient sedation. In these latter cases, the animals were either excited or known for their aggressive character. The zebras were sufficiently immobilized for the length of most procedures (<45 min) without supplementation. At the end of the procedure, the animals were given atipamezole (2 mg per 1 mg detomidine used) and naltrexone (0.1 mg/kg) to reverse the sedative effects, irrespective of whether etorphine was used or not. Standing sedation, using the combination of the alpha-2 agonist detomidine and the partial agonist-antagonist opioid butorphanol (in some cases supplemented with etorphine + acepromazine), proved to be a very efficacious and safe method to be used in zebras under zoo conditions for short-lasting, nonpainful procedures.  相似文献   

12.
Safe, effective, and reversible immobilization protocols are essential for the management of free-ranging red wolves (Canis rufus). Combinations using an alpha2-adrenoceptor agonist and ketamine have been shown to be effective for immobilization but are not reversible and can produce severe hypertension and prolonged or rough recoveries. To minimize hypertension and provide reversibility, 24 red wolves were immobilized using three medetomidine-butorphanol (MB) combinations without the use of ketamine in the initial injection. All wolves were administered medetomidine (0.04 mg/kg i.m.) and butorphanol (0.4 mg/kg i.m.). Seven wolves received no other immobilization agents (MB wolves), nine received diazepam (0.2 mg/kg i.v.) at the time they were instrumented (MBD wolves), and eight received ketamine (1 mg/kg i.v.) 30 min after instrumentation (MBK30 wolves). Physiologic parameters were monitored during immobilization. The heart rate was similar among the three groups for the first 30 min, and marked bradycardia was noted in one wolf from each group. Hypertension was observed initially in all three groups but was resolved within 10-30 min. The MBK30 wolves had significant elevations in heart rate and transient hypertension after intravenous ketamine administration. Most wolves had mild to moderate metabolic acidemia. Immobilizing drugs were antagonized in all wolves with atipamezole (0.2 mg/kg i.m.) and naloxone (0.02 mg/kg i.m.). The medetomidine-butorphanol-diazepam wolves were also given flumazenil (0.04 mg/kg i.v.). All wolves were standing within 12 min and were fully recovered within 17 min. Medetomamine-butorphanol and MBD combinations provided effective and reversible immobilization of red wolves without the sustained hypertension associated with the use of alpha2-adrenoceptor agonist-ketamine combinations. Delaying the administration of ketamine reduced its hypertensive effects.  相似文献   

13.
Using a crossover study design, the pharmacokinetics of carfentanil and naltrexone after i.v., i.m., and s.c. administration were determined in eight domestic goats (Capra hircus). Serial blood samples were taken up to 120 hr after carfentanil administration, and the plasma drug concentrations were determined using liquid chromatography and mass spectroscopy. All goats were immobilized with 40 microg/kg carfentanil i.m., although the resulting neurologic effects varied considerably. Plasma profiles showed rapid carfentanil absorption and a simple biphasic decline for 12-48 hr. Naltrexone given at 100 mg naltrexone/mg carfentanil 30 min after carfentanil administration produced rapid reversal of immobilization after all routes of administration. Variable fluctuations in the naltrexone plasma concentrations during the first 2.5-3.5 hr were observed, followed by a more consistent biphasic decline. The time to standing was significantly shorter after i.v. compared with s.c. naltrexone, although the time difference (1 min) had little clinical relevance. No statistically significant differences between the naltrexone pharmacokinetic parameters measured for the three routes of naltrexone administration were identified, although the recoveries after i.m. administration were, subjectively, the smoothest. The carfentanil half-life did not differ significantly in the goats given naltrexone by different routes. Although it is currently recommended that the naltrexone dose be divided into s.c. and i.v. portions, this practice does not appear to offer any benefit.  相似文献   

14.
The pharmacokinetics of marbofloxacin were investigated in healthy (n=8) and Mannheimia haemolytica naturally infected (n=8) Simmental ruminant calves following intravenous (i.v.) and intramuscular (i.m.) administration of 2 mg kg(-1) body weight. The concentration of marbofloxacin in plasma was measured using high performance liquid chromatography with ultraviolet detection. Following i.v. administration of the drug, the elimination half-life (t(1/2 beta)) and mean residence time (MRT) were significantly longer in diseased calves (8.2h; 11.13 h) than in healthy ones (4.6 h; 6.1 h), respectively. The value of total body clearance (CL(B)) was larger in healthy calves (3 ml min(-1) kg(-1)) than in diseased ones (1.3 ml min(-1) kg(-1)). After single intramuscular (i.m.) administration of the drug, the elimination half-life, mean residence time (MRT) and maximum plasma concentration (C(max)) were higher in diseased calves (8.0, 12 h, 2.32 microg ml(-1)) than in healthy ones (4.7, 7.4 h, 1.4 microg ml(-1)), respectively. The plasma concentrations and AUC following administration of the drug by both routes were significantly higher in diseased calves than in healthy ones. Protein binding of Marbofloxacin was not significantly different in healthy and diseased calves. The mean value for MIC of marbofloxacin for M. haemolytica was 0.1+/-0.06 microg ml(-1). The C(max)/MIC and AUC(24)/MIC ratios were significantly higher in diseased calves (13.0-64.4 and 125-618 h) than in healthy calves (8-38.33 and 66.34-328 h). The obtained results for surrogate markers of antimicrobial activity (C(max)/MIC, AUC/MIC and T > or = MIC) indicate the excellent pharmacodynamic characteristics of the drug in diseased calves with M. haemolytica, which can be expected to optimize the clinical efficacy and minimize the development of resistance.  相似文献   

15.
OBJECTIVE: To evaluate the effects of 2 remifentanil infusion regimens on cardiovascular function and responses to nociceptive stimulation in propofol-anesthetized cats. ANIMALS: 8 adult cats. PROCEDURES: On 2 occasions, cats received acepromazine followed by propofol (6 mg/kg then 0.3 mg/kg/min, i.v.) and a constant rate infusion (CRI) of remifentanil (0.2 or 0.3 microg/kg/ min, i.v.) for 90 minutes and underwent mechanical ventilation (phase I). After recording physiologic variables, an electrical stimulus (50 V; 50 Hz; 10 milliseconds) was applied to a forelimb to assess motor responses to nociceptive stimulation. After an interval (> or = 10 days), the same cats were anesthetized via administration of acepromazine and a similar infusion regimen of propofol; the remifentanil infusion rate adjustments that were required to inhibit cardiovascular responses to ovariohysterectomy were recorded (phase II). RESULTS: In phase I, heart rate and arterial pressure did not differ between remifentanil-treated groups. From 30 to 90 minutes, cats receiving 0.3 microg of remifentanil/kg/min had no response to noxious stimulation. Purposeful movement was detected more frequently in cats receiving 0.2 microg of remifentanil/kg/min. In phase II, the highest dosage (mean +/- SEM) of remifentanil that prevented cardiovascular responses was 0.23 +/- 0.01 microg/kg/min. For all experiments, mean time from infusion cessation until standing ranged from 115 to 140 minutes. CONCLUSIONS AND CLINICAL RELEVANCE: Although the lower infusion rate of remifentanil allowed ovariohysterectomy to be performed, a CRI of 0.3 microg/kg/min was necessary to prevent motor response to electrical stimulation in propofol-anesthetized cats. Recovery from anesthesia was prolonged with this technique.  相似文献   

16.
Parenteral anesthetic protocols for short-term immobilization were evaluated in twenty 4-yr-old Gulf of Mexico sturgeon (Acipenser oxyrinchus de soti). An initial dose-response trial determined the efficacy of either propofol (3.5-7.5 mg/kg. i.v.) or combinations of medetomidine (0.03-0.07 mg/kg, i.m.)-ketamine (3-7 mg/kg, i.m.). A subsequent study evaluated the physiologic effects of propofol (6.5 mg/kg, i.v.)-induced anesthesia and anesthesia induced with a medetomidine (0.06 mg/kg, i.m.)-ketamine (6 mg/kg i.m.) combination. The effects of medetomidine were reversed at 30 min with atipamezole (0.30 mg/kg, i.m.). Both drug protocols provided adequate short-term immobilization for minor diagnostic procedures. Sturgeon receiving propofol were in a light plane of anesthesia within 5 min after drug administration, whereas only 30% of the medetomidine-ketamine group reached a light plane of anesthesia in the same time period. Both propofol and medetomidine-ketamine resulted in mild bradycardia and apparent respiratory depression, with propofol producing more profound effects. At the dosages used in this study, both propofol and the medetomidine-ketamine combination effectively induced a light plane of anesthesia. Induction times were shorter in the propofol group.  相似文献   

17.
The pharmacokinetic parameters of carfentanil and naltrexone were determined in the common eland (Taurotragus oryx). Six adult females were immobilized with xylazine (0.23 +/- 0.03 mg/kg i.m.) and carfentanil (0.0169 +/- 0.0005 mg/kg i.m.) for a 45-min period, during which time routine health care procedures were performed. Heart and respiration rates and body temperatures were monitored throughout the immobilization period. A single intramuscular injection of naltrexone (1.66 +/- 0.08 mg/kg i.m.) was sufficient for reversal. The eland were intermittently restrained in a hydraulic squeeze chute for serial blood sample collection via jugular venipuncture during immobilization and up to 48 hr post-immobilization. The quantification of carfentanil and naltrexone in the plasma was performed by liquid chromatography and mass spectroscopy methods. Carfentanil was rapidly absorbed following administration, with the peak plasma concentration (C(max)) at 13.8 min. Naltrexone was readily absorbed and reached C(max) at 23.4 +/- 16.8 min after administration. All animals stood 2.7 +/- 2.2 min after naltrexone administration. Carfentanil has a half-life of 7.7 hr, whereas naltrexone has a much shorter half-life of 3.7 hr. Although respiratory rates appeared to fluctuate widely among animals, heart rates and body temperature remained stable throughout the immobilization. Renarcotization was not noted as a major complication.  相似文献   

18.
The pharmacokinetics of amikacin (AMK) were investigated after intravenous (i.v.) and intramuscular (i.m.) administration of 7.5 mg/kg bw in 6 healthy lactating sheep. After i.v. AMK injection (as a bolus), the elimination half-life (t1/2beta), the volume of distribution (Vd,area), the total body clearance (ClB) and the area under the concentration-time curve (AUC) were 1.64 +/- 0.06 h, 0.19 +/- 0.02 L/kg, 1.36 +/- 0.1 ml/min per kg and 94.09 +/- 6.95 (microg.h)/ml, respectively. The maximum milk concentration of AMK (Cmax), the area under the milk concentration-time curve (AUCmilk) and the ratio AUCmilk/AUCserum were 1.18 +/- 0.22 microg/ml, 22.45 +/- 3.21 (micro.h)/ml and 0.24 +/- 0.02, respectively. After i.m. administration of AMK the t1/2beta, Cmax, time of Cmax (tmax) and absolute bioavailability (Fabs) were 1.29 +/- 0.1 h, 16.97 +/- 1.54 microg/ml, 1.0 +/- 0 h and 64.88% +/- 6.16%, respectively. The Cmax, AUCmilk and the ratio AUCmilk/AUCserum were 0.33 microg/ml, 1.67 (microg.h)/ml and 0.036, respectively.  相似文献   

19.
Thee different combinations of ketamine hydrochloride were used to induce general anaesthesia for surgical operations (typhlectomy) in 30 adult, single-comb White Leghorn cockerels. They were randomly divided into three groups, each comprising 10 birds. Birds in Group I received xylazine-ketamine combinations at the dose rate of 2 mg xylazine and 10 mg ketamine per kg i.v., whereas birds of Group II received diazepam (2.5 mg/kg i.v.) and 5 min later ketamine (75 mg/kg i.m.). In the Group III, midazolam (2 mg/kg i.m.) and 5 min later ketamine (50 mg/kg i.v.) was administered. The onset of sedation/anaesthesia was shortest (1.60 +/- 0.27 min) in Group I, followed by Group II (8.40 +/- 0.83 min) and Group III (17.10 +/- 1.71 min). Recovery period was shortest in the Group I (65-75 min) followed by Group II (80-85 min) and Group III (92-105 min). Sedation, muscle relaxation and surgical anaesthesia was optimal and excellent in Group I compared with the other two groups. Torticollis, salivation and dyspnoea were observed in Group III. Short-term limb contractions were present in all birds in Groups II and III, up to 20 min of observation. Recovery from anaesthesia was smooth in all three groups. A Surgical procedure (typhlectomy) was performed on all birds. Hypothermia was observed in Group II, whereas heart and respiratory depression was recorded in Group I. Blood sugar level did not vary significantly in any anaesthetic regime. The reduction of haemoglobin was maximum in Group II compared with Groups I and III. Hypoxaemia and hypercapnaea were elevated in all birds in Groups II and III. Blood electrolytes did not vary significantly from the baseline values among the three groups of birds during the period of observation (120 min). The xylazineketamine combination was found to be the best anaesthesia for surgical intervention in chickens.  相似文献   

20.
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   

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