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1.
Objective To evaluate disposition of a single dose of butorphanol in goats after intravenous (IV) and intramuscular (IM) administration and to relate behavioral changes after butorphanol administration with plasma concentrations. Design Randomized experimental study. Animals Six healthy 3‐year‐old neutered goats (one male and five female) weighing 46.5 ± 10.5 kg (mean ± D). Methods Goats were given IV and IM butorphanol (0.1 mg kg?1) using a randomized cross‐over design with a 1‐week interval between treatments. Heparinized blood samples were collected at fixed intervals for subsequent determination of plasma butorphanol concentrations using an enzyme linked immunosorbent assay (ELISA). Pharmacokinetic values (volume of distribution at steady state [VdSS], systemic clearance [ClTB], extrapolated peak plasma concentration [C0] or estimated peak plasma concentration [CMAX], time to estimated peak plasma concentration [TMAX], distribution and elimination half‐lives [t1/2], and bioavailability) were calculated. Behavior was subjectively scored. A two‐tailed paired t‐test was used to compare the elimination half‐lives after IV and IM administration. Behavioral scores are reported as median (range). A Friedman Rank Sums test adjusted for ties was used to analyze the behavioral scores. A logit model was used to determine the effect of time and concentration on behavior. A value of p < 0.05 was considered significant. Results Volume of distribution at steady state after IV administration of butorphanol was 1.27 ± 0.73 L kg?1, and ClTB was 0.0096 ± 0.0024 L kg?1 minute?1. Extrapolated C0 of butorphanol after IV administration was 146.5 ± 49.8 ng mL?1. Estimated CMAX after IM administration of butorphanol was 54.98 ± 14.60 ng mL?1, and TMAX was 16.2 ± 5.2 minutes; bioavailability was 82 ± 41%. Elimination half‐life of butorphanol was 1.87 ± 1.49 and 2.75 ± 1.93 hours for IV and IM administration, respectively. Goats became hyperactive after butorphanol administration within the first 5 minutes after administration. Behavioral scores for goats were significantly different from baseline at 15 minutes after IV administration and at 15 and 30 minutes after IM administration. Both time and plasma butorphanol concentration were predictors of behavior. Behavioral scores of all goats had returned to baseline by 120 minutes after IV administration and by 240 minutes after IM administration. Conclusions and Clinical Relevance The dose of butorphanol (0.1 mg kg?1, IV or IM) being used clinically to treat postoperative pain in goats has an elimination half‐life of 1.87 and 2.75 hours, respectively. Nonpainful goats become transiently excited after IV and IM administration of butorphanol. Clinical trials to validate the efficacy of butorphanol as an analgesic in goats are needed.  相似文献   

2.
Objective To compare the anti‐nociceptive effect of tramadol, a combination of tramadol‐lidocaine, and lidocaine alone when administered in the epidural space. Study design Experimental randomized cross‐over study. Animals Seven healthy male goats, aged 9–11 months, weight 17.5–25.5 kg. Methods Treatments were lidocaine, 2.86 mg kg?1, tramadol‐lidocaine (1 mg kg?1 and 2.46 mg kg?1, respectively) and tramadol (1 mg kg?1) given into the epidural space. The volume of all treatments was 0.143 mL kg?1. Nociception was tested by pin prick and by pressure from a haemostat clamp. Times to the onset and duration of anti‐nociception in the perineal region were recorded. Recumbency and ataxia were noted. Rectal temperature, heart rate and respiratory rate were recorded before and at 15 minute intervals for 2 hours after the administration of each treatment. Statistical comparison used one‐way anova with a post hoc Duncan’s test as a post hoc. Significance was taken as p < 0.05. Results Times (mean ± SD) to onset of and duration of loss of sensation, respectively in minutes were; lidocaine, 3 ± 1 and 85 ± 11), tramadol‐lidocaine 4 ± 1 and 140 ± 2; tramadol 12 ± 1 and 235 ± 18. Onset and duration times were significantly longer with tramadol than the other two treatments. Duration was significantly longer with tramadol‐lidocaine than with lidocaine alone. With lidocaine treatment all goats were severely ataxic or recumbent, after tramadol‐lidocaine mildly ataxic, and after tramadol not ataxic. Rectal temperature, heart and respiratory rates did not differ significantly from baseline after any treatment. Conclusions and clinical relevance The combination of tramadol‐lidocaine given by epidural injection produced an anti‐nociceptive effect in the perineal region, which was rapid in onset and had a longer duration of action than lidocaine alone. This combination might prove useful clinically to provide analgesia in goats for long‐duration obstetrical and surgical procedures but surgical stimuli were not investigated in this study.  相似文献   

3.
ObjectivesTo compare the anaesthetic effects of varying doses of medetomidine (MED) combined with ketamine (KET) in rats, and to determine the efficacy of atipamezole (ATI) in the reversal of these effects using electroencephalogram (EEG) and assessment of clinical parameters.Study designProspective, randomized experimental trial.AnimalsTwenty-one male Sprague–Dawley rats weighing 300–398 g and aged 8–11 weeks old.MethodsThree groups received intraperitoneal injections of MED (0.2, 0.4 or 0.8 mg kg?1) with KET (60 mg kg?1) (MED-200, MED-400 and MED-800). Atipamezole, at doses five times higher than the previous dose of MED, was then administered intraperitoneally 70 minutes after MED-KET injection. The EEG band powers and spectral edge frequencies (SEFs), respiratory rates, reflex scores to toe-web clamping and behavioural changes were measured. Correlations between EEG parameters and reflex scores were also evaluated.ResultsThe duration of surgical anaesthesia was directly proportional to the dose of MED. Lower frequency bands (δ1 to α2) increased in all groups, and these changes were reversed by ATI. Minimal changes were observed in the higher frequency bands (β1 to γ), but their powers were increased by ATI. The SEFs were decreased in all groups, and they were reversed by ATI. While α1 band power and SEF95 showed strong correlations with the depth of anaesthesia, their changes appeared before the measured decreases in reflex score. Recovery from anaesthesia was extended by increasing the dose of MED.Conclusions and clinical relevanceSpectral EEG parameters may not accurately predict the depth of surgical anaesthesia because they had already changed during the induction of surgical anaesthesia. The ATI dose used in the present study may not be enough for complete reversal of anaesthesia induced by MED-KET.  相似文献   

4.
A central eyeball position is often required during sedation or anaesthesia to facilitate examination of the eye. However, use of neuromuscular blockade to produce a central eye position may result in depressed ventilation. This study evaluated the eyeball position, muscle relaxation and changes in ventilation during general anaesthesia after the IV administration of 0.1 mg kg?1 rocuronium. With client consent, 12 dogs of different breeds, body mass 27.2 ± 11.8 kg, aged 5.6 ± 2.8 years (mean ± SD) were anaesthetized for ocular examination. Pre‐anaesthetic medication was 0.01 mg kg?1 medetomidine and 0.2 mg kg?1 butorphanol IV. Anaesthesia was induced with propofol to effect and maintained with 10 mg kg?1 hour?1 propofol by infusion. The dogs were placed in left lateral recumbency, their trachea intubated and connected to a circle breathing system (Fi O2 = 1.0). All dogs breathed spontaneously. The superficial peroneal nerve of the right hind leg was stimulated every 15 seconds with a train‐of‐four (TOF) stimulation pattern and neuromuscular function was assessed with an acceleromyograph (TOF‐Guard). Adequacy of ventilation was measured with the Ventrak 1550. After 10 minutes of anaesthesia to allow stabilisation of baseline values, 0.1 mg kg?1 rocuronium was administered IV. Minute volume (Vm ), tidal volume (Vt ), respiratory rate (RR), Pe ′CO2 and maximal depression of T1 and TOF ratio were measured. Data were analysed using a paired t‐test. The changes in the eyeball position were recorded. A total of 100 ± 33 seconds after the injection of rocuronium, T1 was maximally depressed to 62 ± 21% and the TOF ratio to 42 ± 18% of baseline values. Both variables returned to baseline after 366 ± 132 seconds (T1) and 478 ± 111 seconds (TOF). There was no significant reduction in Vm (2.32 ± 1.1 L minute?1), Vt (124.1 ± 69.3 mL) and RR (10 ± 3.8 breaths minute?1) and no increase in Pe ′CO2 (6.5 ± 2.1 kPa (48.8 ± 16.1 mm Hg)) throughout the procedure. The eyeball rotated to a central position 35 ± 7 seconds after rocuronium IV and remained there for a minimum of 20 ± 7 minutes in all dogs. We conclude that rocuronium at a dose of 0.1 mg kg?1 can be administered to dogs IV with minimal changes in ventilatory variables. The eyeball is fixed in a central position for at least 20 minutes, which greatly facilitates clinical examination.  相似文献   

5.
Same‐day mass sterilization of feral cats requires rapid onset, short‐duration anesthesia. The purpose of this study was to compare our current anesthetic protocol, Telazol–ketamine–xylazine (TKX) with medetomidine–ketamine–buprenorphine (MKB). Feral female cats received either IM TKX (n = 68; 0.25 mL cat?1; tiletamine 12.5 mg, zolazepam 12.5 mg, K 20 mg, and X 5 mg per 0.25 mL) or MKB (n = 17; M 40 µg kg?1, K 15 mg kg?1, and B 10 µg kg?1). Intervals measured included time from injection to recumbency, time to surgery, duration of surgery, and time from reversal of anesthesia (TKX: yohimbine 0.50 mg cat?1 IV; MKB: atipamezole 0.50 mg cat?1 IM) to sternal recumbency. Following instrumentation (Vet/Ox 4403 and Vet/BP Plus 6500), physiological measurements were recorded at 5‐minute intervals, and included rectal temperature, heart rate (HR), respiratory rate (RR), SpO2 (lingual or rectal probes), and indirect mean arterial blood pressure (MAP) (oscillometric method). Nonparametric means were compared using Mann–Whitney U‐tests. Parametric means were compared using a two‐factorial anova with Bonferroni's t‐tests. The alpha‐priori significance level was p < 0.05. Values were mean ± SD. Body weight (TKX: 2.9 ± 0.5 kg, MKB: 2.7 ± 0.7 kg), time to recumbency (TKX: 4 ± 1 minutes, MKB: 3 ± 1 minutes), time to surgery (TKX: 28 ± 7 minutes, MKB: 28 ± 5 minutes), and duration of surgery (TKX: 11 ± 7 minutes, MKB: 8 ± 5 minutes) did not differ between groups. In contrast, MKB cats required less time from reversal to sternal recumbency (TKX: 68 ± 41 minutes, MKB: 7 ± 2 minutes) and were recumbent for shorter duration (TKX: 114 ± 39 minutes, MKB: 53 ± 6 minutes). Temperature decreased during the study in both groups, but overall temperature was higher in MKB cats (38.0 ± 0.95 °C) than in TKX cats (37.5 ± 0.95 °C). RR, HR, and SpO2 did not change during the study in either group. However, overall HR and RR were higher in TKX cats (RR: 18 ± 8 breaths minute?1, HR: 153 ± 30 beats minute?1) compared to MKB cats (RR: 15 ± 7 breaths minute?1, HR: 128 ± 19 beats minute?1). In contrast, overall SpO2 was lower in the TKX group (90 ± 6%) compared to the MKB group (94 ± 4%). MAP was also lower in the TKX group (112 ± 29 mm Hg) compared to that in the MKB group (122 ± 20 mm Hg). However, MAP increased in the TKX group during surgery compared to pre‐surgical values, but did not change in the MKB group. The results of this study suggested that MKB might be more suitable as an anesthetic for the purpose of mass sterilization of feral female cats.  相似文献   

6.
The purpose of this study was to determine the cardiovascular, analgesic, and sedative effects of IV medetomidine (M, 20 µg kg?1), medetomidine–hydromorphone (MH, 20 µg kg?1 ? 0.1 mg kg?1), and medetomidine–butorphanol (MB, 20 µg kg?1 ? 0.2 mg kg?1) in dogs. Using a randomized cross‐over design and allowing 1 week between treatments, six healthy, mixed‐breed dogs (five males and one female) weighing 20 ± 3 kg, were induced to anesthesia by face‐mask administration of 2.9% ET sevoflurane to facilitate instrumentation prior to administration of the treatment combinations. Dogs were intubated and instrumented to enable measurement of heart rate (HR), systolic arterial pressure (SAP), mean arterial pressure (MAP), diastolic arterial pressure (DAP), mean pulmonary arterial pressure (PAP), pulmonary arterial occlusion pressure (PAOP), central venous pressure (CVP), pulmonary arterial temperature (TEMP), and cardiac output via thermodilution using 5 mL of 5% dextrose, and recording the average of the three replicate measurements. Cardiac index (CI) and systemic (SVR) and pulmonary vascular resistances were calculated. After instrumentation was completed, administration of sevoflurane was discontinued, and the dogs were allowed to recover for 30 minutes prior to administration of the treatment drugs. After collection of the baseline samples for blood gas analysis and recording the baseline cardiovascular variables, the test agents were administered IV over 10 seconds and the CV variables recorded at 5, 10, 15, 30, 45, and 60 minutes post‐injection. In addition, arterial blood was sampled for blood gas analysis at 15 and 45 minutes following injection. Intensity and duration of analgesia (assessed by toe‐pinch response using a hemostat) and level of sedation were evaluated at the above time points and at 75 and 90 minutes post‐injection. Data were analyzed using anova for repeated measures with posthoc differences between means identified using Bonferroni's method (p < 0.05). Administration of M, MH, or MB was associated with increases in SAP, MAP, DAP, PAP, PAOP, CVP, SVR, and TEMP and with decreases in HR and CI. No differences in CV variables between treatment groups were identified at any time. PaO2 increased over time in all groups and was significantly higher when MH was compared with M. At 45 minutes, PaO2 tended to decrease over time and was significantly lower when MH and MB were compared with M at 15 minutes. Analgesia scores for MH and MB were significantly higher compared with M through 45 minutes, while analgesia scores for MH were significantly higher compared with M through 90 minutes. Sedation scores were higher for MH and MB compared with M throughout 90 minutes. Durations of lateral recumbency were 108 ± 10.8, 172 ± 15.5, and 145 ± 9.9 minutes for M, MH, and MB, respectively. We conclude that MH and MB are associated with improved analgesia and sedation and have similar CV effects when compared with M.  相似文献   

7.
Treatment of bradycardia in horses has been historically ignored because of the motility depressant effects of nonselective antimuscarinics. This study evaluated the cardiopulmonary effects of a cardioselective (M2) muscarinic antagonist, methoctramine (MET), in anesthetized horses. In a previous in vitro study, we determined that supraphysiological doses of MET were necessary to inhibit acetylcholine‐induced longitudinal jejunal smooth muscle contractions in this species. Six adult horses were allocated to two treatments in a randomized complete block design. Anesthesia was induced with xylazine/ketamine, and maintained with halothane (1% end‐tidal) and a constant infusion of xylazine (1 mg kg?1 hour?1) under mechanical ventilation. Invasive hemodynamic variables were monitored at baseline (approximately 45 minutes after induction) and for 120 minutes after MET or saline (control) had been injected. MET was titrated at 10‐minute intervals (10 µg kg?1 IV) until the heart rate (HR) increased at least 30% above the baseline, or a maximum cumulative dose of 30 µg kg?1 had been injected. A person blinded to the treatment evaluated recovery scores and monitored intestinal auscultation until 24 hours after the end of anesthesia using previously published methods. Cardiovascular parameters were analyzed by anova followed by a Dunnet's test, and nonparametrical data were analyzed by a Mann–Whitney U‐test (p < 0.05). Values were mean ± SEM unless otherwise stated. MET significantly increased HR from baseline to 120 minutes post‐injection (from 29 ± 1 to 36 ± 2 beats minute?1 at 20 minutes). Thermodilution cardiac output (CO) and mean arterial pressure (MAP) were increased from baseline to 75 minutes post‐MET injection (from 13.9 ± 0.8 to 19.4 ± 2.0 L minute?1 for CO at 20 minutes, and from 82 ± 3 to 103 ± 5 mm Hg for MAP at 20 minutes). Recovery characteristics and bowel auscultation scores did not differ among the groups. The return to at least 75% of the maximum auscultation score occurred at 10 (8–18) hours [median (range)] for controls and at 9 (8–12) hours for MET. It was concluded that MET increased HR and improved hemodynamic function during halothane/xylazine anesthesia with no apparent effect on return to full‐bowel motility, as assessed by auscultation. Accordingly, M2 muscarinic antagonists might be represented as a safer alternative to treat intraoperative bradycardia in horse.  相似文献   

8.
Objective To examine the effect of dose and route of administration on the sedative‐hypnotic effects of midazolam. Design Prospective randomized controlled study Animals Six indigenous, African bred goats. Methods Pilot studies indicated that the optimum dose of midazolam for producing sedation was 0.6 mg kg?1 for intramuscular (IM) injection, while the optimum intravenous (IV) doses causing hypnosis without, and with loss of palpebral reflexes were 0.6 mg kg?1 and 1.2 mg kg?1, respectively. These doses and routes of administration were compared with a saline placebo in a randomized block design in the main experiment, and the sedative‐hypnotic effects evaluated according to pre‐determined scales. Results Intramuscular midazolam produced sedation with or without sternal recumbency in all animals with the peak effect occurring 20 minutes after administration. The scores for IM sedation with midazolam were significantly different (p < 0.05) from placebo. Intravenous midazolam at 0.6 mg kg?1 resulted in hypnosis, and at 1.2 mg kg?1 increased reflex suppression was observed. The maximum scores for hypnosis at both doses were obtained 5 minutes after IV injection. The mean (± SD) duration of lateral recumbency was 10.8 (± 3.8) minutes after IV midazolam (0.6 mg kg?1) compared to 20 (± 5.2) minutes after midazolam at 1.2 mg kg?1. Compared to baseline, the heart rate increased significantly (p < 0.05) after high dose IV midazolam. Conclusion Intramuscular midazolam (0.6 mg kg?1) produced maximum sedation 20 minutes after injection. Intravenous injection produced maximum hypnosis within 5 minutes. Increasing the IV dose from 0.6 to 1.2 mg kg?1 resulted in increased reflex suppression and duration of hypnosis. Clinical relevance For a profound effect with rapid onset midazolam should be given IV in doses between 0.6 and 1.2 mg kg?1.  相似文献   

9.
Objective To compare behavioral characteristics of induction and recovery in horses anesthetized with eight anesthetic drug protocols. Study design Randomized prospective experimental study. Animals Eight horses, 5.5 ± 2.4 years (mean ± SD) of age, and weighing 505 ± 31 kg. Methods After xylazine pre‐medication, each of eight horses was anesthetized on four occasions using one of eight different anesthetic induction protocols which incorporated various combinations of ketamine (KET), propofol (PRO), and thiopental (THIO): THIO 8 mg kg?1; THIO 6 mg kg?1 + PRO 0.5 mg kg?1; THIO 4 mg kg?1 + PRO 1 mg kg?1; THIO 2 mg kg?1 + PRO 1.5 mg kg?1; KET 2 mg kg?1; KET 1.5 mg kg?1 + PRO 0.5 mg kg?1; KET 1 mg kg?1 + PRO 1 mg kg?1; KET 0.5 mg kg?1 + PRO 1.5 mg kg?1. Quality of induction and recovery were scored from 1 (poor) to 5 (excellent), and time taken to achieve lateral recumbency, first movement, sternal recumbency, and standing were evaluated. Results Time taken to achieve lateral recumbency after drug administration differed significantly (p < 0.0001) among the various combinations, being shortest in horses receiving THIO‐8 (mean ± SD, 0.5 ± 0.3 minutes) and longest in horses receiving KET‐2 (1.4 ± 0.2 minutes). The best scores for induction quality were associated with KET‐1.5 + PRO‐0.5, and the worst scores for induction quality were associated with KET‐2, although the difference was not significant. Time to first movement varied significantly among drug protocols (p = 0.0133), being shortest in horses receiving KET‐2 (12.7 ± 3.6 minutes) and longest in horses receiving THIO‐8 (29.9 ± 1.5 minutes). Horses receiving THIO‐8 made the greatest number of attempts to attain sternal posture (6.5 ± 4.7) and to stand (1.6 ± 0.8). Horses in the THIO‐8 treatment also received the poorest recovery scores (3.3 ± 1.0 and 3.0 ± 0.7 for sternal and standing postures, respectively). The best recovery scores were associated with combinations comprised mainly of propofol. Conclusions Combining propofol with either ketamine or thiopental modifies behaviors associated with use of the individual drugs. Clinical relevance Quality of early anesthesia recovery in horses may be improved by some combinations of propofol with either thiopental or ketamine.  相似文献   

10.
ObjectiveTo evaluate the antagonistic effects of atipamezole (ATI), flumazenil (FLU) and naloxone (NAL) alone and in various combinations following administration of tiletamine–zolazepam–xylazine–tramadol.Study designProspective, experimental, randomized cross-over study.AnimalsEight Chinese miniature pigs (three females and five males) mean age 8 (range 7–10) months and bodyweight 57.5 (52.4–62.1) kg.MethodsAll animals were anaesthetized with tiletamine/zolazepam (3.0 mg kg?1), xylazine (1.2 mg kg?1) and tramadol (1.6 mg kg?1) given intramuscularly (IM). Thirty minutes later, one of eight treatments was administered IM: saline control, ATI (0.12 mg kg?1), FLU (0.1 mg kg?1), NAL (0.03 mg kg?1), ATI–FLU, FLU–NAL, ATI–NAL or ATI–FLU–NAL. After injection of antagonists the following times were recorded: to recovery of the palpebral, pedal and tail clamp reflexes, to head movement, sternal recumbency, standing and walking. Posture, sedation, analgesia, jaw relaxation and auditory response were scored at set times until 120 minutes after injection of antagonists. Heart rates, respiratory rates and rectal temperature were measured at those times. Data were analyzed by anova for repeated measures, followed by the Tukey’s test to compare differences between means, or by Kruskal–Wallis test as appropriate.ResultsFLU, NAL alone, or FLU–NAL did not effectively antagonize anaesthesia induced by tiletamine/zolazepam–xylazine–tramadol. ATI, ATI–FLU, ATI–NAL and ATI–FLU–NAL produced an immediate and effective recovery from anaesthesia. The combination of ATI–FLU–NAL was the most effective combination in antagonizing the anaesthetic effect. Adverse effects such as tachycardia, tachypnoea, excitement and muscle tremors were not observed during this study.Conclusion and clinical relevanceATI–FLU–NAL is the most effective combination for antagonizing tiletamine/zolazepam–xylazine–tramadol anaesthesia in pigs. However, ATI alone or in various combinations also provides effective antagonism.  相似文献   

11.
This clinical study analysed the anaesthetic sparing effect of a medetomidine constant rate infusion (CRI) during isoflurane anaesthesia in horses. Forty healthy horses undergoing different types of orthopaedic and soft tissue surgeries were studied in a randomized trial. Orthopaedic surgeries were primarily arthroscopies and splint bone extractions. Soft tissue surgeries were principally castrations with one ovariectomy. All horses received 0.03 mg kg?1 acepromazine IM 1 hour prior to sedation. Group A (11 orthopaedic and nine soft tissue surgeries), was sedated with 1.1 mg kg?1 xylazine IV, group B (13 orthopaedic and seven soft tissue surgeries) with 7 µg kg?1 medetomidine IV. Anaesthesia was induced in both groups with 2.2 mg kg?1 ketamine and diazepam 0.02 mg kg?1 IV. Maintenance of anaesthesia was with isoflurane (ISO) in 100% oxygen, depth of anaesthesia was always adjusted by the first author. Group B received an additional CRI of 3.5 µg kg?1 hour?1 medetomidine. Respiratory rate (RR), heart rate (HR), mean arterial blood pressure (MAP), Fe ′ISO and Fe ′CO2 were monitored with a methane insensitive monitor (Cardiocap 5, Ohmeda, Anandic, Diessenhofen) and noted every 5 minutes. Arterial blood was withdrawn for gas analysis (PaO2, PaCO2) 5 minutes after the induction of anaesthesia and every 30 minutes thereafter. Dobutamine (DOB) was given as a CRI to maintain mean arterial blood pressure above 70 mm Hg. Data were averaged over time (sum of measurements/number of measurements) and tested for differences between groups by unpaired t‐tests. There were no significant differences between the groups in terms of body mass (group A, 508 ± 73.7 kg; group B, 529.25 ± 78.4 kg) or duration of anaesthesia (group A, 125.5 ± 36 minutes; group B, 121.5 ± 48.4 minutes). The mean Fe ′ISO required to maintain a surgical plane of anaesthesia was significantly higher in group A (1.33 ± 0.13%) than in group B (1.07 ± 0.19%; p = 2.78 × 10?5). Heart rate was different between the two groups (group A, 42.2 ± 8.3; group B, 32.6 ± 3.5; p = 8.8 × 10?5). Dobutamine requirements were higher in group A (group A, 0.72 ± 0.24 μg kg?1 minute?1; group B, 0.53 ± 0.23 μg kg?1 minute?1; p = 0.023). Respiratory rate, Fe ′CO2, PaO2, PaCO2 were not different between the groups. Adjustment of anaesthetic depth subjectively was easier with the medetomidine infusion and isoflurane (group B) than with isoflurane as a sole agent (group A). In group A 12 horses and in group B five horses showed purposeful movements on 27 (A) and 12 (B) occasions. They were given thiopental (group A, 0.0114 mg kg?1 minute?1; group B, 0.0023 mg kg?1 minute?1). In group A, a further 17 horses were given ketamine to deepen anaesthesia (52 occasions, 0.00426 mg kg?1 minute?1) whereas in group B only nine horses needed ketamine (34 occasions, 0.00179 mg kg?1 minute?1). An infusion of 3.5 µg kg?1 MED during ISO anaesthesia resulted in a significantly reduced ISO requirement.  相似文献   

12.
Objective To directly compare the time to onset and duration of analgesia produced by a lidocaine/xylazine combination with that produced by lidocaine and xylazine administered alone in the caudal epidural space of dairy cattle. Design Prospective randomized experimental study. Animals Nine adult (> 4 years of age) dairy cows (520–613 kg). Methods Caudal epidural analgesia was produced in all cows with 2% lidocaine (0.22 mg kg?1; 5.5 mL 500 kg?1), 10% xylazine (0.05 mg kg?1 diluted to 5.5 mL 500 kg?1 with sterile water), and 2% lidocaine/10% xylazine (0.22 mg kg?1/0.05 mg kg?1; total volume of 5.7 mL 500 kg?1), at no earlier than weekly intervals in a Latin square design. Time to onset, duration and cranial spread of analgesia were recorded, as were degree of sedation, ataxia and ptyalism. Results No significant difference (p > 0.05) was noted for time (mean ± SEM) of onset of analgesia between lidocaine (4.8 ± 1.0 minutes) and the lidocaine/xylazine combination (5.1 ± 0.9 minutes) but onset of analgesia following xylazine was significantly longer (11.7 ± 1.0 minutes) than either of the other two treatments. Lidocaine/xylazine (302.8 ± 11.0 minutes) produced analgesia of significantly longer duration than that of xylazine (252.9 ± 18.9 minutes) and both the lidocaine/xylazine combination and xylazine alone produced analgesia of significantly longer duration than that produced by lidocaine (81.8 ± 11.8 minutes). In all cattle, xylazine, administered either alone or with lidocaine, induced mild to moderate sedation and ataxia and cutaneous analgesia from the coccyx to T13. Mild ataxia was also present in those cattle receiving lidocaine alone. Conclusion The combination of xylazine and lidocaine produces analgesia of quicker onset and longer duration than xylazine administered alone and of longer duration than lidocaine administered alone. Clinical relevance Utilizing this combination, long‐duration obstetrical and surgical procedures could commence relatively soon after epidural injection and could be completed without re‐administration of anesthetic agents.  相似文献   

13.
Objective To characterize intravenous anaesthesia with detomidine, ketamine and guaiphenesin in pregnant ponies. Animals Twelve pony mares, at 260–320 days gestation undergoing abdominal surgery to implant fetal and maternal vascular catheters. Materials and methods Pre‐anaesthetic medication with intravenous (IV) acepromazine (30 µg kg?1), butorphanol (20 µg kg?1) and detomidine (10 µg kg?1) preceded induction of anaesthesia with detomidine (10 µg kg?1) and ketamine (2 mg kg?1) IV Maternal arterial blood pressure was measured directly throughout anaesthesia and arterial blood samples were taken at 20‐minute intervals for measurement of blood gases and plasma concentrations of cortisol, glucose and lactate. Anaesthesia was maintained with an IV infusion of detomidine (0.04 mg mL?1), ketamine (4 mg mL?1) and guaiphenesin (100 mg mL?1) (DKG) for 140 minutes. Oxygen was supplied by intermittent positive pressure ventilation (IPPV) adjusted to maintain PaCO2 between 5.0 and 6.0 kPa (38 and 45 mm Hg), while PaO2 was kept close to 20.0 kPa (150 mm Hg) by adding nitrous oxide. Simultaneous fetal and maternal blood samples were withdrawn at 90 minutes. Recovery quality was assessed. Results DKG was infused at 0.67 ± 0.17 mL kg?1 hour?1 for 1 hour then reduced, reaching 0.28 ± 0.14 mL kg?1 hour?1 at 140 minutes. Arterial blood gas values and pH remained within intended limits. During anaesthesia there was no change in heart rate, but arterial blood pressure decreased by 10%. Plasma glucose and lactate increased (10‐fold and 2‐fold, respectively) and cortisol decreased by 50% during anaesthesia. Fetal umbilical venous pH, PO2 and PCO2 were 7.34 ± 0.06, 5.8 ± 0.9 kPa (44 ± 7 mm Hg) and 6.7 ± 0.8 kPa (50 ± 6 mm Hg); and fetal arterial pH, PO2 and PCO2 were 7.29 ± 0.06, 4.0 ± 0.7 kPa (30 ± 5 mm Hg) and 7.8 ± 1.7 kPa (59 ± 13 mm Hg), respectively. Surgical conditions were good but four ponies required a single additional dose of ketamine. Ponies took 60 ± 28 minutes to stand and recovery was good. Conclusions and clinical relevance Anaesthesia produced with DKG was smooth while cardiovascular function in mare and fetus was well preserved. This indicates that DKG infusion is suitable for maintenance of anaesthesia in pregnant equidae.  相似文献   

14.
In order to use rice straw as forage in livestock feeding, the effects of steam-treated rice straw (at 15.5 kgf/cm2 for 120 s) feeding on growth performance, plasma volatile fatty acid profile, and nutrient digestibility of goats were determined. Twenty male goats (18.69?±?0.34 kg) were used in an 84-day trial. The goats were divided into four groups of five goats each to receive steam-treated (STRS) or untreated (UTRS) rice straw diet under closed house (CH) and open house (OH) systems. The results revealed that the goats fed with STRS had significantly higher dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), and acid detergent fiber (ADF) digestibility; similarly, the average daily weight gain and feed conversion ratio were higher for STRS groups under both CH and OH systems than those for UTRS. The plasma protein and insulin in STRS and cholesterol in UTRS groups was higher (P?P?>?0.05) at 30 days. The plasma amylase, lipase, T3, T4 and glucagon at 30 and 60 days were not different (P?>?0.05) among the groups. The plasma acetate, propionate, butyrate, and total volatile fatty acid were higher (P?P?>?0.05) on these parameters. It could be concluded that steam treatment of rice straw at 15.5 kgf/cm2 for 120 s increased apparent nutrient digestibility, hence increased the growth and feed efficiency of growing goats.  相似文献   

15.
ObjectiveTo assess the effects of intravenous (IV) medetomidine-butorphanol and IV dexmedetomidine-butorphanol on intraocular pressure (IOP).Study designProspective, randomized, blinded clinical study.AnimalsForty healthy dogs. Mean ± SD body mass 37.6 ± 6.6 kg and age 1.9 ± 1.3 years.MethodsDogs were allocated randomly to receive an IV combination of dexmedetomidine, 0.3 mg m?2, combined with butorphanol, 6 mg m?2, (group DEX) or medetomidine 0.3 mg m?2, combined with butorphanol 6 mg m?2, (group MED). IOP and pulse (PR) and respiratory (fR) rates were measured prior to (baseline) and at 10 (T10), 20 (T20), 30 (T30) and 40 (T40) minutes after drug administration. Oxygen saturation of hemoglobin (SpO2) was monitored following sedation. Data were analyzed by anova followed by Dunnett's tests for multiple comparisons. Changes were considered significant when p < 0.05.ResultsFollowing drug administration, PR and fR were decreased significantly at all time points but did not differ significantly between groups. Baseline IOP in mmHg was 14 ± 2 for DEX and 13 ± 2 for MED. With both treatments, at T10, IOP increased significantly (p < 0.001), reaching 20 ± 3 and 17 ± 2 for DEX and MED respectively. This value for DEX was significantly higher than for MED. There were no significant differences in IOP values between groups at any other time points. At T30 and T40, IOP in both groups was below baseline (DEX, 12 ± 2 and 11 ± 2: MED 12 ± 2 and 11 ± 2) and this was statistically significant, for DEX.Conclusions and clinical relevanceAt the documented doses, both sedative combinations induced a transient increase and subsequent decrease of IOP relative to baseline, which must be taken into consideration when planning sedation of animals in which marked changes in IOP would be undesirable.  相似文献   

16.
The aim of the present study was to clarify the relation between salsolinol (SAL)‐induced prolactin (PRL) release and photoperiod in goats. A single intravenous (i.v.) injection of SAL was given to adult female goats under short (8 h light, 16 h dark) or long (16 h light, 8 h dark) photoperiod conditions at two different ambient temperatures (20°C or 5°C), and the PRL‐releasing response to SAL was compared to that of thyrotropin‐releasing hormone (TRH) or a dopamine (DA) receptor antagonist, sulpiride. SAL, as well as TRH or sulpiride, stimulated the release of PRL promptly after each injection in both 8‐ and 16‐h daily photoperiods at 20°C (P < 0.05). The area under the response curve (AUC) of PRL for the 60‐min period after injections of saline (controls), SAL, TRH and sulpiride in the 16‐h daily photoperiod group was greater than each corresponding value in the 8‐h daily photoperiod group (P < 0.05). There were no significant differences in the AUC of PRL among the values produced after the injection of SAL, TRH and sulpiride in 16‐h daily photoperiod group; however, the values produced after the injection of TRH were smallest among the three in the 8‐h daily photoperiod group (P < 0.05). The PRL‐releasing responses to SAL, TRH and sulpiride under a short and long photoperiod condition at 5°C resembled those at 20°C. These results show that a long photoperiod highly enhances the PRL‐releasing response to SAL as well as TRH or sulpiride in either medium or low ambient temperature in goats.  相似文献   

17.
The secretion of prolactin (PRL) is under the dominant and tonic inhibitory control of dopamine (DA); however, we have recently found that salsolinol (SAL), an endogenous DA‐derived compound, strongly stimulated the release of PRL in ruminants. The aim of the present study was to clarify the inhibitory effect of DA on the SAL‐induced release of PRL in ruminants. The experiments were performed from late June to early July. Male goats were given a single intravenous (i.v.) injection of SAL (5 mg/kg body weight (BW)), a DA receptor antagonist (sulpiride, 0.1 mg/kg BW), or thyrotropin‐releasing hormone (TRH, 1 µg/kg BW) before and after treatment with a DA receptor agonist (bromocriptine), and the effect of DA on SAL‐induced PRL release was compared to that on sulpiride‐ or TRH‐induced release. Bromocriptine completely inhibited the SAL‐induced release of PRL (P < 0.05), and the area under the response curve (AUC) for a 120‐min period after the treatment with bromocriptine was 1/28 of that for before the treatment (P < 0.05). Bromocriptine also completely inhibited the sulpiride‐induced release (P < 0.05). The AUC post‐treatment was 1/17 that of pre‐treatment with bromocriptine (P < 0.05). Bromocriptine also inhibited the TRH‐induced release (P < 0.05), though not completely. The AUC post‐treatment was 1/3.8 that of pre‐treatment (P < 0.05). These results indicate that DA inhibits the SAL‐induced release of PRL in male goats, and suggest that SAL and DA are involved in regulating the secretion of PRL. They also suggest that in terms of the regulatory process for the secretion of PRL, SAL resembles sulpiride but differs from TRH.  相似文献   

18.

Objective

To evaluate intravenous (IV) detomidine with methadone in horses to identify a combination which provides sedation and antinociception without adverse effects.

Study design

Randomized, placebo-controlled, blinded, crossover.

Animals

A group of eight adult healthy horses aged (mean ± standard deviation) 7 ± 2 years and 372 ± 27 kg.

Methods

A total of six treatments were administered IV: saline (SAL); detomidine (5 μg kg?1; DET); methadone (0.2 mg kg?1; MET) alone or combined with detomidine [2.5 (MLD), 5 (MMD) or 10 (MHD) μg kg?1]. Thermal, mechanical and electrical nociceptive thresholds were measured, and sedation, head height above ground (HHAG), cardiopulmonary variables and intestinal motility were evaluated at 5, 15, 30, 45, 60, 75, 90, 120 and 180 minutes. Normal data were analyzed by mixed-model analysis of variance and non-normal by Kruskal–Wallis (p < 0.05).

Results

Nociceptive thresholds in horses administered methadone with the higher doses of detomidine (MMD, MHD) were increased above baseline to a greater degree and for longer duration (MMD: 15–30 minutes, MHD: 30–60 minutes) than in horses administered low dose with methadone or detomidine alone (MLD, DET: 5–15 minutes). No increases in nociceptive thresholds were recorded in SAL or MET. Compared with baseline, HHAG was lower for 30 minutes in MMD and DET, and for 45 minutes in MHD. No significant sedation was observed in SAL, MET or MLD. Intestinal motility was reduced for 75 minutes in MHD and for 30 minutes in all other treatments.

Conclusions

Methadone (0.2 mg kg?1) potentiated the antinociception produced by detomidine (5 μg kg?1), with minimal sedative effects.

Clinical relevance

Detomidine (5 μg kg?1) with methadone (0.2 mg kg?1) produced antinociception without the adverse effects of higher doses of detomidine.  相似文献   

19.
Alpha2 agonists have a significant role in epidural anaesthetic techniques. However, there are few reports regarding epidural administration of these drugs especially in small animals ( Greene et al. 1995; Keegan et al. 1995; Vesal et al. 1996 ). This study compared the haemodynamic effects of xylazine and medetomidine after epidural injection in dogs. Six dogs (four females and two males) weighing 27.5 ± 3.39 kg, aged 5.6 ± 1.42 years were studied on two separate occasions one month apart. Dogs were sedated with 0.5 mg kg?1 diazepam IM and 0.1 mg kg?1 acepromazine IM. After 20 minutes, a lumbosacral epidural injection of 0.25 mg kg?1 xylazine was administered (group X). One month later, following the same sedation, 15 µg kg?1 medetomidine was administered epidurally (group M). Haemodynamic variables (ECG and indirect blood pressure (Doppler)), respiratory rate and rectal temperature were recorded before (baseline) and then every 5 minutes after the epidural injection, up to 60 minutes. Differences between groups were compared by a paired t‐test. Within group changes were compared to basal values by anova . A p‐value of < 0.05 was considered statistically significant. Both groups showed significant reductions in heart rate (106.3 ± 7.7 beats minute?1 baseline versus 67.7 ± 7.6 (group M); 91 ± 3.8 baseline versus 52.3 ± 9 (group X)) and mean arterial blood pressure (113.1 ± 12.3 mm Hg baseline versus 87 ± 11 (group M); 118 ± 7 baseline versus 91 ± 14 (group X)). There were no differences between groups in these variables. After epidural injection, first degree atrioventricular block was recorded significantly more often in group X (50% against 33%) but second degree block was significantly more frequent in group M (66% against 33%). Also 50% of dogs in group X and 66% in group M showed sinus arrest. Respiratory rate decreased significantly in both groups following the epidural injection (20.66 ± 0.66 minute?1 baseline versus 16.33 ± 4.77 (group M); 37.66 ± 0.56 baseline versus 16.33 ± 1.81 group X), but no differences between groups were observed. Rectal temperature decreased significantly in group X (38.16 ± 0.21) with respect to the basal measurement (39.30 ± 0.14 °C). In group M, there was no significant reduction in temperature, however, no statistical difference in rectal temperature was found between groups. This study shows that 0.25 mg kg?1 xylazine and 15 µg kg?1 medetomidine produce similar, significant cardiovascular and respiratory changes following lumbosacral epidural administration in dogs.  相似文献   

20.
The purpose of this study was to determine the cardiovascular effects of sodium nitroprusside (SNP)‐induced after load reduction in dogs administered dexmedetomidine (DEX). Using a randomized crossover design and allowing at least 2 weeks between treatments 12 adult hound dogs of either sex weighing 22 ± 1.7 SD kg were anesthetized by face mask administration of 2.9% ET sevoflurane to facilitate instrumentation prior to administration of treatment drugs. Dogs were intubated and instrumented to enable measurement of heart rate (HR), systolic (SAP), mean (MAP) and diastolic (DAP) arterial pressures, mean pulmonary arterial pressure (PAP), pulmonary capillary wedge pressure (PCWP), central venous pressure (CVP), pulmonary arterial temperature (TEMP), and cardiac output (CO). Systemic (SVR) and pulmonary vascular resistances were calculated. Following completion of instrumentation dogs were allowed to recover for 40 minutes. After collection of baseline data, dogs were administered one of four treatments at T–10 minutes prior to injection of DEX (500? g M–2 IM): 1) saline (SAL); 2) atropine (ATR, 0.02 [n = 6] or 0.04 [n = 6] mg kg–1 IM); 3) SAL + SNP (infused at 1–10 ?g kg–1 minute–1, IV as needed to maintain MAP between 90–110 mm Hg; or 4) ATR + SNP. Cardiovascular data were collected at T‐20 minutes prior to administration of DEX, T‐5 and at 5, 10, 20, 30, 40, and 60 minutes following DEX. Data were analyzed using anova for repeated measures with post hoc differences between means identified using Bonferroni's method (p < 0.05). Differences in ATR dose were not found to be significant and thus results for ATR dose groups were pooled. Administration of SAL (dexmedetomidine alone) was associated with decreases in HR and CO and increases in SAP, MAP, DAP, CVP, and SVR. Administration of ATR was associated with an increase in HR and CO compared with SAL. Administration of SNP was associated with an increase in HR and CO and a decrease in SVR, MAP and CVP compared with SAL. Administration of SNP + ATR was associated with effects similar to that of SNP or ATR alone and resulted in an additive increase in CO. We conclude that SNP‐induced afterload reduction with or without atropine is effective in mitigating DEX‐induced impairment of cardiovascular function.  相似文献   

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