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1.
Bruno H. Pypendop M.G. Ranasinghe Kirby Pasloske 《Veterinary anaesthesia and analgesia》2018,45(5):630-639
Objectives
To determine the context-sensitive half-time of alfaxalone following intravenous infusions of various durations. To estimate the time necessary for plasma concentration to decrease by up to 95%.Study design
Prospective randomized and simulation studies.Animals
A group of six 1-year-old male castrated research cats.Methods
Cats were instrumented with catheters in a jugular and a medial saphenous vein. Alfaxalone was administered using a target-controlled infusion system, to target a plasma alfaxalone concentration of 7.6 mg L–1. The infusion lasted 30 (n = 2), 60 (n = 2) or 240 (n = 2) minutes. Blood samples were collected prior to drug administration, and at several times during and up to 8 hours after the infusion, for the determination of plasma alfaxalone concentration using liquid chromatography/tandem mass spectrometry. Compartment models were fitted to each time–concentration profile, and a population model was fitted to data from all individuals. The context-sensitive half-time was determined from each individual model. In addition, times for plasma alfaxalone concentration to decrease by 50–95% following bolus administration and target-controlled infusions or continuous rate infusions of 0.5–8 hours were estimated by simulation using the population model.Results
Context-sensitive half-times were 2 and 8, 6 and 9, and 18 and 20 minutes for the 30, 60 and 240 minutes, respectively. Time for plasma alfaxalone concentration to decrease by 90% was predicted to range from 7 to 120 or 113 minutes following a bolus to an 8 hour target-controlled or continuous rate infusion, respectively.Conclusion and clinical relevance
Recovery time from alfaxalone anesthesia in cats is predicted to be influenced by the duration of target-controlled infusion. 相似文献2.
D Rodrigo-Mocholí E Escudero E Belda FG Laredo V Hernandis 《New Zealand veterinary journal》2018,66(4):172-177
AIMS: To determine the pharmacokinetics, and anaesthetic and sedative effects of alfaxalone after I/V and I/M administration to cats.METHODS: Six European shorthair cats, three males and three females, with a mean weight of 4.21 (SD 0.53) kg and aged 3.8 (SD 0.9) years were enrolled in this crossover, two–treatment, two-period study. Alfaxalone at a dose of 5?mg/kg was administered either I/V or I/M. Blood samples were collected between 2–480 minutes after drug administration and analysed for concentrations of alfaxalone by HPLC. The plasma concentration-time curves were analysed by non-compartmental analysis. Sedation scores were evaluated between 5–120 minutes after drug administration using a numerical rating scale (from 0–18). Intervals from drug administration to sit, sternal and lateral recumbency during the induction phase, and to head-lift, sternal recumbency and standing position during recovery were recorded.RESULTS: The mean half-life and mean residence time of alfaxalone were longer after I/M (1.28 (SD 0.21) and 2.09 (SD 0.36) hours, respectively) than after I/V (0.49 (SD 0.07) and 0.66 (SD 0.16) hours, respectively) administration (p<0.05). Bioavailability after I/M injection of alfaxalone was 94.7 (SD 19.8)%. The mean intervals to sternal and lateral recumbency were longer in the I/M (3.73 (SD 1.99) and 6.12 (SD 0.90) minutes, respectively) compared to I/V (0 minutes for all animals) treated cats (p<0.01). Sedation scores indicative of general anaesthesia (scores >15) were recorded from 5–15 minutes after I/V administration and deep sedation (scores 11–15) at 20 and 30 minutes. Deep sedation was observed from 10–45 minutes after I/M administration. One cat from each group showed hyperkinesia during recovery, and the remainder had an uneventful recovery.CONCLUSIONS AND CLINICAL RELEVANCE: Alfaxalone administered I/V in cats provides rapid and smooth induction of anaesthesia. After I/M administration, a longer exposure to the drug and an extended half life were obtained compared to I/V administration. Therefore I/M administration of alfaxalone could be a reliable, suitable and easy route in cats, taking into account that alfaxalone has a slower onset of sedation than when given I/V and achieves deep sedation rather than general anaesthesia. 相似文献
3.
Bruno H. Pypendop Kristine T. Siao M.G. Ranasinghe Kirby Pasloske 《Veterinary anaesthesia and analgesia》2018,45(3):269-277
Objective
To determine the effective plasma alfaxalone concentration for the production of immobility in cats.Study design
Prospective up-and-down study.Animals
Sixteen 1–2 year old male castrated research cats.Methods
Cats were instrumented with catheters in a jugular and a medial saphenous vein. Alfaxalone was administered via the medial saphenous catheter, using a target-controlled infusion system. The infusion lasted for approximately 32 minutes. A noxious stimulus (tail clamp) was applied 30 minutes after starting the alfaxalone infusion, until the cat moved or 60 seconds had elapsed, whichever occurred first. The target alfaxalone concentration was set at 5 mg L?1 in the first cat and increased or decreased by 1 mg L?1 in subsequent cats, if the previous cat had moved or not moved in response to stimulation, respectively. This was continued until six independent crossovers (different responses in pairs of subsequent cats) had been observed. Blood samples were collected before alfaxalone administration, and 15 and 31 minutes after starting the administration, for the determination of plasma alfaxalone concentration using liquid chromatography/tandem mass spectrometry. The alfaxalone concentration yielding a probability of immobility in 50% (EC50), 95% (EC95) and 99% (EC99) of the population, and their respective 95% Wald confidence intervals were calculated.Results
The EC50, EC95 and EC99 for alfaxalone-induced immobility were 3.7 (2.4–4.9), 6.2 (4.7–) and 7.6 (5.5–) mg L?1, respectively.Conclusions and clinical relevance
The effective plasma alfaxalone concentration for immobility in cats was determined. This value will help in the design of pharmacokinetic-based dosing regimens. 相似文献4.
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Julia Deutsch Colette Jolliffe Emma Archer Elizabeth A. Leece 《Veterinary anaesthesia and analgesia》2017,44(4):794-802
Objective
To assess quality of sedation following intramuscular (IM) injection of two doses of alfaxalone in combination with butorphanol in cats.Study design
Prospective, randomized, ‘blinded’ clinical study.Animals
A total of 38 cats undergoing diagnostic imaging or noninvasive procedures.Methods
Cats were allocated randomly to be administered butorphanol 0.2 mg kg?1 combined with alfaxalone 2 mg kg?1 (group AB2) or 5 mg kg?1 (group AB5) IM. If sedation was inadequate, alfaxalone 2 mg kg?1 IM was administered and cats were excluded from further analysis. Temperament [1 (friendly) to 5 (aggressive)], response to injection, sedation score at 2, 6, 8, 15, 20, 30, 40, 50 and 60 minutes, overall sedation quality scored after data collection [1 (excellent) to 4 (inadequate)] and recovery quality were assessed. Heart rate (HR), respiratory rate (fR) and arterial haemoglobin saturation (SpO2) were recorded every 5 minutes. Groups were compared using t tests and Mann–Whitney U tests. Sedation was analysed using two-way anova, and additional alfaxalone using Fisher's exact test (p < 0.05).Results
Groups were similar for sex, age, body mass and response to injection. Temperament score was lower in group AB2 [2 (1–3)] compared to AB5 [3 (1–5)] (p = 0.006). Group AB5 had better sedation at 6, 8, 20 and 30 minutes and overall sedation quality was better in AB5 [1 (1–3)], compared to AB2 [3 (1–4)] (p = 0.0001). Additional alfaxalone was required for 11 cats in AB2 and two in AB5 (p = 0.005). Recovery quality, HR, fR and SpO2 were similar. Seven cats required oxygen supplementation. Complete recovery times were shorter in AB2 (81.8 ± 24.3 versus 126.6 ± 33.3 minutes; p = 0.009). Twitching was the most common adverse event.Conclusions and clinical relevance
In combination with butorphanol, IM alfaxalone at 5 mg kg?1 provided better quality sedation than 2 mg kg?1. Monitoring of SpO2 is recommended. 相似文献6.
The bioequivalence of a single intravenous administration of the anesthetic alfaxalone in cyclodextrin versus alfaxalone in cyclodextrin plus preservatives in cats
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K. Pasloske M. G. Ranasinghe S. Sauer J. Hare 《Journal of veterinary pharmacology and therapeutics》2018,41(3):437-446
To demonstrate the bioequivalence of alfaxalone in cyclodextrin (Reference Product) to a formulation of alfaxalone in cyclodextrin also containing the preservatives ethanol, chlorocresol, and benzethonium chloride (Test Product) when administered for the purpose of inducing anesthesia in the cat. Blinded, single‐dose, randomized, two‐period, two‐sequence, cross‐over bioequivalence study with a 7‐day washout period between treatments. Twenty‐four (12 neutered males and 12 intact females), healthy, adult cats weighing 4.1±0.9 kg. Cats were administered 5 mg/kg IV of alfaxalone in the Reference or Test Product using a randomized cross‐over design. One‐milliliter venous blood samples were collected at predetermined time points to 12 hr after drug administration to determine alfaxalone plasma concentration over time. Alfaxalone concentrations were determined by a validated analytical testing method using HPLC‐MS/MS. Plasma profiles of alfaxalone concentration against time were analyzed by noncompartmental analysis. The pivotal variables for bioequivalence were AUClast and Cmax. Equivalence was achieved if the 90% confidence interval for AUClast and Cmax fell into the asymmetric ±20% interval (0.80–1.25). Physiological variables, quality of anesthesia visual analog scale (VAS) scoring and anesthetic event times were recorded. ANOVA or ANCOVA (single time point), RMANOVA or RMANCOVA (multiple time point) was used for normally distributed data. GLIMMIX was used for nonnormally distributed data. VAS scores were analyzed as for blood bioequivalence data. Variables were evaluated for safety and assessed at alpha = 0.10. Cmax and AUClast for Reference and Test Products were statistically bioequivalent. No physiological variables except for a drug by time interaction for respiratory rate differed between treatment groups, and this difference was not clinically relevant. No anesthetic event times or VAS scores for quality of anesthesia were different between treatment groups. Neither formulation caused pain upon injection. The Reference and Test Products are pharmaceutically bioequivalent formulations when administered as a single intravenous administration for the purpose of induction of anesthesia in cats. 相似文献
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William Muir DVM PhD Diplomate ACVA Diplomate ACVECC Phillip Lerche DVM PhD Diplomate ACVA Ashley Wiese DVM MS Laura Nelson DVM Kirby Pasloske† DVM DVSc Diplomate ACVCP & Ted Whittem† BVSc PhD DACVCP 《Veterinary anaesthesia and analgesia》2009,36(1):42-54
ObjectiveTo determine the cardiorespiratory and anesthetic effects of 0, 5, 15, and 50 mg kg?1 intravenous (IV) alfaxalone in hydroxypropyl beta cyclodextrin (Alfaxan; Jurox Pty Ltd, Rutherford, NSW, Australia) in cats.Study designFour treatments of alfaxalone were administered in sequential order.AnimalsEight healthy adult cats (four male; four female) weighing between 3.71 and 5.91 kg.MethodsCats were instrumented for hemodynamic measurements. Four (0, 5, 15, and 50 mg kg?1) IV doses of alfaxalone were administered over one minute, with a 3-hour washout period between doses 0, 5, and 15 mg kg?1 on Day 0. The 50 mg kg?1 treatment was administered 24 hours later. Measurements of heart rate, aortic systolic, mean, and diastolic blood pressures, pulmonary arterial and right atrial mean pressures, cardiac output, respiratory rate, tidal and minute volumes, and arterial blood pH and blood gases (PaO2, PaCO2) were performed at pre-determined intervals. Systemic vascular resistance and rate pressure product were calculated. The quality of induction, maintenance, and recovery from anesthesia and the response to noxious stimulation were categorically scored.ResultsAlfaxalone administration resulted in dose-dependent cardiorespiratory depression. Decreases in arterial blood pressure and increases in heart rate occurred at higher doses. Most variables returned to baseline by 15-30 minutes. Respiratory rate, minute volume, and PaO2 decreased. Apnea was the most common side effect. Induction and maintenance quality were judged to be good to excellent at all doses and quality of recovery good to excellent at all but the 50 mg kg?1 dose. The duration of anesthesia and unresponsiveness to noxious stimulation increased with dose. The administration of the 50 mg kg?1 dose produced marked cardiorespiratory depression and apnea.Conclusions and clinical relevanceAlfaxalone produced dose-dependent anesthesia, cardiorespiratory depression and unresponsiveness to noxious stimulation in unpremedicated cats. Hypoventilation and apnea were the most common side effects. 相似文献
10.
Katherine J. Bennett Reza Seddighi Kaitlin A. Moorhead Kristin Messenger Sherry K. Cox Xiaocun Sun Kirby Pasloske Bruno H. Pypendop Thomas J. Doherty 《Veterinary anaesthesia and analgesia》2019,46(2):173-181
Objective
To determine the effect of fentanyl on the induction dose and minimum infusion rate of alfaxalone required to prevent movement in response to a noxious stimulus (MIRNM) in dogs.Study design
Experimental crossover design.Animals
A group of six healthy, adult, intact female mixed-breed dogs, weighing 19.7 ± 1.3 kg.Methods
Dogs were randomly administered one of three treatments at weekly intervals: premedication with 0.9% saline (treatment A), fentanyl 5 μg kg–1 (treatment ALF) or fentanyl 10 μg kg–1 (treatment AHF), administered intravenously over 5 minutes. Anesthesia was induced 5 minutes later with incremental doses of alfaxalone to achieve intubation and was maintained for 90 minutes in A with alfaxalone (0.12 mg kg–1 minute–1), in ALF with alfaxalone (0.09 mg kg–1 minute–1) and fentanyl (0.1 μg kg–1 minute–1) and in AHF with alfaxalone (0.06 mg kg–1 minute–1) and fentanyl (0.2 μg kg–1 minute–1). The alfaxalone infusion was increased or decreased by 0.006 mg kg–1 minute–1 based on positive or negative response to antebrachium stimulation (50 V, 50 Hz, 10 ms). Data were analyzed using a mixed-model anova and presented as least squares means ± standard error.Results
Alfaxalone induction doses were 3.50 ± 0.13 (A), 2.17 ± 0.10 (ALF) and 1.67 ± 0.10 mg kg–1 (AHF) and differed among treatments (p < 0.05). Alfaxalone MIRNM was 0.17 ± 0.01 (A), 0.10 ± 0.01 (ALF) and 0.07 ± 0.01 mg kg–1 minute–1 (AHF) and differed among treatments. ALF and AHF decreased the MIRNM by 44 ± 8% and 62 ± 5%, respectively (p < 0.05). Plasma alfaxalone concentrations at MIRNM were 5.82 ± 0.48 (A), 4.40 ± 0.34 (ALF) and 2.28 ± 0.09 μg mL–1 (AHF).Conclusions and clinical relevance
Fentanyl, at the doses studied, significantly decreased the alfaxalone induction dose and MIRNM. 相似文献11.
Brighton T. Dzikiti Patience S. Ndawana Loveness N. Dzikiti Frik G. Stegmann 《Veterinary anaesthesia and analgesia》2018,45(3):285-294
Objective
To determine the minimum infusion rate (MIR) of alfaxalone required to prevent purposeful movement in response to standardized stimulation while co-administered with lidocaine at three different doses by constant infusion rate infusion (CRI) in goats.Study design
Prospective, blinded, randomized crossover, experimental.Animals
A total of eight healthy goats: four does and four wethers.Methods
Anaesthetic induction was with lidocaine at 1 mg kg?1 [low dose of lidocaine (L-Lid)], 2 mg kg?1 [moderate dose (M-Lid)] or 4 mg kg?1 [high dose (H-Lid)] and alfaxalone at 2 mg kg?1. Anaesthetic maintenance was with alfaxalone initially at 9.6 mg kg?1 hour?1 combined with one of three lidocaine treatments: 3 mg kg?1 hour?1 (L-Lid), 6 mg kg?1 hour?1 (M-Lid) or 12 mg kg?1 hour?1 (H-Lid). The MIR of alfaxalone was determined by testing for responses to a stimulation in the form of clamping on a digit with a Vulsellum forceps every 30 minutes during lidocaine CRI. Basic cardiopulmonary parameters were measured.Results
The alfaxalone MIRs were 8.64 (6.72–10.56), 6.72 (6.72–8.64) and 6.72 (6.72–6.72) mg kg?1 hour?1 during L-Lid, M-Lid and H-Lid, respectively, without any significant differences among treatments. Compared to the initial rate of 9.6 mg kg?1 hour?1, these reductions in MIR are equivalent to 10, 30 and 30%, respectively. Significant increases in heart rate (HR) and arterial carbon dioxide partial pressure (PaCO2) and decreases in arterial haemoglobin saturation (SaO2), arterial oxygen partial pressure (PaO2) and respiratory frequency (fR) immediately after induction were observed during all lidocaine treatments.Conclusions and clinical relevance
Lidocaine reduces the alfaxalone MIR by up to 30% with a tendency towards a plateauing in this effect at high CRIs. Immediate oxygen supplementation might be required to prevent hypoxaemia. 相似文献12.
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Andrea Schwarz Karin Kalchofner Julia Palm Stephanie Picek Sonja Hartnack Regula Bettschart‐Wolfensberger 《Veterinary anaesthesia and analgesia》2014,41(5):480-490
ObjectiveTo determine the induction doses, then minimum infusion rates of alfaxalone for total intravenous anaesthesia (TIVA), and subsequent, cardiopulmonary effects, recovery characteristics and alfaxalone plasma concentrations in cats undergoing ovariohysterectomy after premedication with butorphanol-acepromazine or butorphanol-medetomidine.Study designProspective randomized blinded clinical study.AnimalsTwenty-eight healthy cats.MethodsCats undergoing ovariohysterectomy were assigned into two groups: together with butorphanol [0.2 mg kg?1 intramuscularly (IM)], group AA (n = 14) received acepromazine (0.1 mg kg?1 IM) and group MA (n = 14) medetomidine (20 μg kg?1 IM). Anaesthesia was induced with alfaxalone to effect [0.2 mg kg?1 intravenously (IV) every 20 seconds], initially maintained with 8 mg kg?1 hour?1 alfaxalone IV and infusion adjusted (±0.5 mg kg?1 hour?1) every five minutes according to alterations in heart rate (HR), respiratory rate (fR), Doppler blood pressure (DBP) and presence of palpebral reflex. Additional alfaxalone boli were administered IV if cats moved/swallowed (0.5 mg kg?1) or if fR >40 breaths minute?1 (0.25 mg kg?1). Venous blood samples were obtained to determine plasma alfaxalone concentrations. Meloxicam (0.2 mg kg?1 IV) was administered postoperatively. Data were analysed using linear mixed models, Chi-squared, Fishers exact and t-tests.ResultsAlfaxalone anaesthesia induction dose (mean ± SD), was lower in group MA (1.87 ± 0.5; group AA: 2.57 ± 0.41 mg kg?1). No cats became apnoeic. Intraoperative bolus requirements and TIVA rates (group AA: 11.62 ± 1.37, group MA: 10.76 ± 0.96 mg kg?1 hour?1) did not differ significantly between groups. Plasma concentrations ranged between 0.69 and 10.76 μg mL?1. In group MA, fR, end-tidal carbon dioxide, temperature and DBP were significantly higher and HR lower.Conclusion and clinical relevanceAlfaxalone TIVA in cats after medetomidine or acepromazine sedation provided suitable anaesthesia with no need for ventilatory support. After these premedications, the authors recommend initial alfaxalone TIVA rates of 10 mg kg?1 hour?1. 相似文献
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Maria Valentina Carrozzo Jane Alcorn Barbara Ambros 《Veterinary anaesthesia and analgesia》2018,45(6):831-838
Objective
To determine the pharmacokinetics and effects on thermal thresholds (TT) of two fentanyl constant rate infusions in awake cats.Study design
A blinded, randomized crossover study.Animals
A group of six healthy female cats, aged 3 ± 1 years, weighing 4.1 ± 0.7 kg.Methods
Skin temperature (TSKIN) and TT were evaluated using a wireless TT device. TSKIN, TT, sedation score (SS) and blood samples were collected before an intravenous loading dose (LD; over 5 seconds) and at specific time points during (360 minutes) and after infusion. Each cat was administered two treatments: fentanyl (LD 3 μg kg?1, infusion 3 μg kg?1 hour?1; treatment F3) or fentanyl (LD 5 μg kg?1, infusion 5 μg kg?1 hour?1; treatment F5). SS between treatments was analyzed using a Kruskal–Wallis test. Statistical analysis of TT and TSKIN was performed using analysis of variance with appropriate post hoc test (p < 0.05).Results
TSKIN did not vary over time for each treatment. SS did not differ between treatments. TTs were significantly higher than baseline at 15 minutes after LD for F3 and F5. TT was significantly increased at 30, 90, 120, 180 and 300 minutes in treatment F5 but not in F3. Plasma fentanyl concentrations decreased rapidly in both treatments over the first 30 minutes after infusion. The terminal half-life was 3.31 (2.93–4.41) hours for F3 and 3.67 (3.39–4.32) hours for F5 (median, range). Systemic clearance for treatments F3 and F5 was 1.95 (1.46–2.44) and 2.25 (1.98–2.47) L hour?1 kg?1 (median, range), respectively. Plasma concentrations <1.84 ng mL?1 were not associated with a significant increase in TT.Conclusions
and clinical relevance A fentanyl infusion rate of 5 μg kg?1 hour?1 increased TT during the infusion period. Effects on TT were lost rapidly with cessation of the infusion. 相似文献16.
ObjectiveTo compare the anaesthetic and cardiopulmonary effects of alfaxalone with propofol when used for total intravenous anaesthesia (TIVA) during ovariohysterectomy in dogs.Study designA prospective non-blinded randomized clinical study.AnimalsFourteen healthy female crossbred bitches, aged 0.5–5 years and weight 16–42 kg.MethodsDogs were premedicated with acepromazine 0.01 mg kg?1 and morphine 0.4 mg kg?1. Anaesthesia was induced and maintained with either propofol or alfaxalone to effect for tracheal intubation followed by an infusion of the same agent. Dogs breathed spontaneously via a ‘circle’ circuit, with oxygen supplementation. Cardiopulmonary parameters (respiratory and heart rates, end-tidal carbon dioxide, tidal volume, and invasive blood pressures) were measured continuously and recorded at intervals related to the surgical procedure. Arterial blood samples were analysed for blood gas values. Quality of induction and recovery, and recovery times were determined. Non-parametric data were tested for significant differences between groups using the Mann–Whitney U-test and repeatedly measured data (normally distributed) for significant differences between and within groups by anova.ResultsBoth propofol and alphaxalone injection and subsequent infusions resulted in smooth, rapid induction and satisfactory maintenance of anaesthesia. Doses for induction (mean ± SD) were 5.8 ± 0.30 and 1.9 ± 0.07 mg kg?1 and for the CRIs, 0.37 ± 0.09 and 0.11 ± 0.01 mg kg?1 per minute for propofol and alfaxalone respectively. Median (IQR) recovery times were to sternal 45 (33–69) and 60 (46–61) and to standing 74 (69–76) and 90 (85–107) for propofol and alphaxalone respectively. Recovery quality was good. Cardiopulmonary effects did not differ between groups. Hypoventilation occurred in both groups.Conclusions and clinical relevanceFollowing premedication with acepromazine and morphine, both propofol and alphaxalone produce good quality anaesthesia adequate for ovariohysterectomy. Hypoventilation occurs suggesting a need for ventilatory support during prolonged infusion periods with either anaesthetic agent. 相似文献
17.
Determination of the minimum infusion rate of alfaxalone during its co‐administration with fentanyl at three different doses by constant rate infusion intravenously in goats
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Brighton T Dzikiti Patience S Ndawana Gareth Zeiler Jacques P Ferreira Loveness N Dzikiti 《Veterinary anaesthesia and analgesia》2016,43(3):316-325
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Muir W Lerche P Wiese A Nelson L Pasloske K Whittem T 《Veterinary anaesthesia and analgesia》2008,35(6):451-462
ObjectiveTo determine the cardiorespiratory and anesthetic effects of 2, 6, and 20 mg kg−1 IV alfaxalone in hydroxypropyl beta cyclodextrin (Alfaxan) in dogs.Study designBlinded four-way crossover randomized by dose.AnimalsEight healthy adult purpose-bred mixed breed dogs (four male, four female) weighing between 12 and 28 kg.MethodsFour (0, 2, 6, 20 mg kg−1) IV treatments of alfaxalone were administered to each dog with a 3-hour washout period between doses. Measurements of heart rate, aortic systolic, mean, and diastolic blood pressures, pulmonary arterial and right atrial mean pressures, cardiac output, respiratory rate, tidal and minute volumes, and arterial blood pH, blood gases (PaO2, PaCO2) were performed prior to and at predetermined intervals after drug administration. Systemic vascular resistance and rate pressure product were calculated. The quality of induction, maintenance, and recovery from anesthesia were categorically scored as was the response to noxious stimulation.ResultsThe administration of alfaxalone resulted in dose-dependent changes in cardiovascular and respiratory parameters. Decreases in arterial blood pressure and increases in heart rate occurred at higher doses with most variables returning to baseline in 15–30 minutes. Respiratory rate, minute volume, and PaO2 decreased and apnea was the most common side effect. The duration of anesthesia increased with dose, and induction, maintenance, and recovery were judged to be good to excellent with all doses studied.Conclusions and clinical relevanceAlfaxalone produced good to excellent short-term anesthesia in unpremedicated dogs. Cardiorespiratory effects were minimal at lower doses. Anesthesia was judged to be good to excellent and associated with unresponsiveness to noxious stimulation for the majority of anesthesia. Hypoventilation and apnea were the most prominent and dose-dependent effects. 相似文献
19.
《Veterinary anaesthesia and analgesia》2022,49(5):473-476
ObjectiveTo compare two commercial formulations of alfaxalone for immersion anaesthesia in laboratory zebrafish.Study designProspective, blinded, randomized study.AnimalsA total of 20 adult Danio rerio (Tuebingen strain).MethodsZebrafish were divided into two groups of 10 (five female, five male) and placed in individual immersion baths containing 10 mg L–1 of unpreserved alfaxalone (group 1) or preserved alfaxalone (group 2). Anaesthetists blinded to treatment used a composite score scale (CSS) (range 0–12) to assess fish every 30 seconds until induction of anaesthesia. Anaesthetic induction occurred when equilibrium and response to stimulus were lost. Fish were then placed in a clean water bath and scored every 60 seconds. Recovery from anaesthesia was defined as a CSS of ≤ 1. Time variables recorded were anaesthetic induction time (AIT), anaesthetic recovery time (ART) and total procedure time (TPT). Fish were observed for evidence of roupgross external pathology during the procedure. Following anaesthesia, four fish from each group were randomly chosen and euthanized for gill histopathology analysis immediately after recovery criteria were met. Data are presented as mean ± standard deviation. An independent t test was used to compare the difference in average anaesthetic time variables between groups (α = 0.05).ResultsThere were no statistical differences between groups in reported variables. TPT, AIT and ART were 10.2 ± 1.2, 1.9 ± 0.9 and 8.3 ± 1.2 minutes for group 1 and 10.8 ± 2.9, 2.4 ± 1.2 and 8.4 ± 2.7 minutes for group 2. No gross external pathology was evident, and no fish died during the experimental period. Histopathology showed normal gill pathology and no difference between the groups.Conclusions and clinical relevanceImmersion anaesthesia using 10 mg L–1 of either formulation of alfaxalone resulted in anaesthesia of similar quality and duration. 相似文献
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Carlos Ros Carme Soler Alejandra García de Carellán Mateo 《Veterinary anaesthesia and analgesia》2017,44(5):1085-1090