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1.
OBJECTIVE: To compare the doses of propofol required for insertion of the laryngeal mask airway (LMA) with those for endotracheal intubation in sedated dogs. STUDY DESIGN: Randomized prospective clinical study. Animals Sixty healthy dogs aged 0.33-8.5 (3.0 +/- 2.3, mean +/- SD) years, weighing 2.2-59.0 (23.4 +/- 13.6, mean +/- SD) kg, presented for elective surgery requiring inhalation anaesthesia. METHODS: Animals were randomly assigned to receive either a LMA or an endotracheal tube. Pre-anaesthetic medication was intravenous (IV) glycopyrrolate (0.01 mg kg(-1)) medetomidine (10 microg kg(-1)) and butorphanol (0.2 mg kg(-1)). Repeated IV propofol injections (1 mg kg(-1) in 30 seconds) were given until LMA insertion or endotracheal intubation was achieved, when the presence or absence of laryngospasm, the respiratory rate (fr) and the total dose of propofol used were recorded. RESULTS: The total propofol dose (mean +/- SD) required for LMA insertion (0.53 +/- 0.51 mg kg(-1)) was significantly lower than for endotracheal intubation (1.43 +/- 0.57 mg kg(-1)). The LMA could be inserted without propofol in 47% of dogs; the remainder needed a single 1 mg kg(-1) bolus (n = 30). Endotracheal intubation was possible without propofol in 3.3% of the dogs, 47% needed one bolus and 50% required two injections (n = 30). The f(r) (mean +/- SD) was 18 +/- 6 and 15 +/- 7 minute(-1) after LMA insertion and intubation, respectively. CONCLUSION AND CLINICAL RELEVANCE: Laryngeal mask airway insertion requires less propofol than endotracheal intubation in sedated dogs therefore propofol-induced cardiorespiratory depression is likely to be less severe. The LMA is well tolerated and offers a less invasive means of securing the upper airway.  相似文献   

2.
Spontaneous ventilation after induction of anaesthesia with intravenous alfaxalone or propofol was evaluated in a dose escalation study using 6 dogs. Each dog was dosed at 1×, 2×, 5×, 10× and 20× multiples of the labelled doses (2mg/kg for alfaxalone; 6.5mg/kg for propofol), until apnoea was observed. For each administration, the entire calculated dose was delivered over 1 min. All 6 dogs ventilated spontaneously after labelled (1×) doses of each drug but became apnoeic at 5× dose of propofol versus 20× dose of alfaxalone. For propofol at 2× and 5× doses, 4 and 0 dogs ventilated spontaneously respectively. For alfaxalone at 2×, 5× and 10× doses all 6, 4 and 1 dog ventilated spontaneously, respectively. The median dose which induced apnoea was higher for alfaxalone (5×) than for propofol (2×) (p=0.05). We concluded that induction of anaesthesia with propofol is more likely to induce apnoea than with alfaxalone.  相似文献   

3.
This study aimed to determine the pharmacokinetic parameters and pharmacodynamics of alfaxalone in a 2‐hydroxypropyl‐β‐cyclodextrin alfaxalone formulation (Alfaxan®, Jurox Pty Ltd, Rutherford, NSW, Australia) in cats after single administration at clinical and supraclinical dose rates and as multiple maintenance doses. First, a prospective two‐period cross‐over study was conducted at single clinical and supraclinical doses. Second, a single group multiple dose study evaluated the effect of maintenance doses. Eight (five female and three male) domestic cats completed the cross‐over experiment and six female cats completed the multiple dose study. In the first experiment, alfaxalone was administered intravenously (IV) at 5 or 25 mg/kg with a washout period of 14 days. In the second experiment, alfaxalone was administered IV at 5 mg/kg followed by four doses each of 2 mg/kg, administered at onset of responsiveness to a noxious stimulus. Blood was collected at prescribed intervals and analysed by LCMS for plasma alfaxalone concentration. Noncompartmental pharmacokinetics were used to analyse the plasma alfaxalone data. The plasma clearance of alfaxalone at 5 and 25 mg/kg differed statistically at 25.1 and 14.8 mL/kg/min respectively. The elimination half lives were 45.2 and 76.6 min respectively. Alfaxalone has nonlinear pharmacokinetics in the cat. Nevertheless, for cats dosed with sequential maintenance doses, a regression line through their peak plasma concentrations indicated that there was no clinically relevant pharmacokinetic accumulation. The duration of nonresponsiveness after each maintenance dose was similar at approximately 6 min, indicating a lack of accumulation of pharmacodynamic effect. The cardiovascular and respiratory parameters measured in cats after administration of the labelled doses of Alfaxan® were stable. In conclusion, the pharmacokinetics of alfaxalone in cats are nonlinear. At clinical dose rates, however, neither alfaxalone nor its effects accumulated to a clinically relevant extent. Further, in the un‐premedicated cat the induction and maintenance of surgical anaesthesia was free of untoward events after a dose of 5 mg alfaxalone/kg body weight followed by four sequential doses of 2 mg/kg as needed (i.e., approximately 7 to 8 mg/kg/h).  相似文献   

4.
OBJECTIVE: To compare the quality of surgical anaesthesia and cardiorespiratory effects of three intramuscular (IM) anaesthetic combinations in rabbits. STUDY DESIGN: Prospective randomized cross-over experimental study. ANIMALS: Nineteen adult female chinchilla mixed-bred rabbits weighing 3.9 +/- 0.8 kg. METHODS: Rabbits were given one of three IM anaesthetic combinations: 0.25 mg kg(-1) medetomidine and 35.0 mg kg(-1) ketamine (M-K), 0.20 mg kg(-1) medetomidine and 0.02 mg kg(-1) fentanyl and 1.0 mg kg(-1) midazolam (M-F-Mz) and 4.0 mg kg(-1) xylazine and 50 mg kg(-1) ketamine (X-K). The effects of anaesthesia on nociceptive reflexes, circulatory and respiratory function were recorded. Statistical analyses involved repeated measures anova with paired Student's t-test applied post hoc. P-values <0.05 were considered as significant. RESULTS: Reflex loss was most rapid and complete in M-K recipients, whereas animals receiving M-F-Mz showed the longest tolerance of endotracheal intubation (78.1 +/- 36.5 minutes). Loss of righting reflex was significantly most rapid (p < 0.05) in the X-K group (114.7 +/- 24.0 minutes). Surgical anaesthesia was achieved in 16 of 19 animals receiving M-K, in 14 animals receiving M-F-Mz, and in seven animals with X-K, but only for a short period (7.1 +/- 11.6 minutes). This was significantly (p < 0.001) shorter than with M-K (38.7 +/- 30.0 minutes) and M-F-Mz (31.6 +/- 26.6 minutes). Heart rates were greatest in X-K recipients; lowest HR were seen in animals receiving M-F-Mz. Mean arterial blood pressure was significantly higher (about 88 mmHg) during the first hour in the M-K group. During recovery, the greatest hypotension was encountered in the X-K group; minimum values were 53 +/- 12 mmHg. Six of 19 animals in the M-F-Mz group showed a short period of apnoea (30 seconds) immediately after endotracheal intubation. Respiratory frequency was significantly lower in this group (p < 0.001). Highest values for arterial carbon dioxide partial pressures (PaCO(2)) (6.90 +/- 0.87 kPa; 52.5 +/- 6.5 mmHg) occurred after induction of anaesthesia in group M-F-Mz animals. There was a marked decrease in PaO(2) in all three groups (the minimum value 5.28 +/- 0.65 kPa [39.7 +/- 4.9 mmHg] was observed with M-K immediately after injection). Arterial PO(2) was between 26.0 and 43.0 kPa (196 and 324 mmHg) in all groups during O(2) delivery and decreased - but not <7.98 kPa - on its withdrawal. Immediately after drug injection, pH(a) values fell in all groups, with lowest values after 30 minutes (7.23 +/- 0.03 with M-K, 7.28 +/- 0.05 with M-F-Mz, and 7.36 +/- 0.04 with X-K). The X-K animals showed significantly (p < 0.001) higher pH values than medetomidine recipients. During 1 hour of anaesthesia pH values in the medetomidine groups remained below those of the X-K group. CONCLUSIONS: Surgical anaesthesia was induced in most animals receiving medetomidine-based combinations. Arterial blood pressure was maintained at baseline values for about 1 hour after M-K. Transient apnoea occurred with M-F-Mz and mandates respiratory function monitoring. Oxygen enrichment of inspired gases is necessary with all three combinations. Endotracheal intubation is essential in rabbits receiving M-F-Mz. CLINICAL RELEVANCE: The quality of surgical anaesthesia was greatest with M-K. All combinations allowed recoveries of similar duration. It is theoretically possible to antagonize each component of the M-F-Mz combination.  相似文献   

5.
ObjectiveTo determine the alfaxalone dose reduction during total intravenous anaesthesia (TIVA) when combined with ketamine or midazolam constant rate infusions and to assess recovery quality in healthy dogs.Study designProspective, blinded clinical study.AnimalsA group of 33 healthy, client-owned dogs subjected to dental procedures.MethodsAfter premedication with intramuscular acepromazine 0.05 mg kg-1 and methadone 0.3 mg kg-1, anaesthetic induction started with intravenous alfaxalone 0.5 mg kg-1 followed by either lactated Ringer’s solution (0.04 mL kg-1, group A), ketamine (2 mg kg-1, group AK) or midazolam (0.2 mg kg-1, group AM) and completed with alfaxalone until endotracheal intubation was achieved. Anaesthesia was maintained with alfaxalone (6 mg kg-1 hour-1), adjusted (±20%) every 5 minutes to maintain a suitable level of anaesthesia. Ketamine (0.6 mg kg-1 hour-1) or midazolam (0.4 mg kg-1 hour-1) were employed for anaesthetic maintenance in groups AK and AM, respectively. Physiological variables were monitored during anaesthesia. Times from alfaxalone discontinuation to extubation, sternal recumbency and standing position were calculated. Recovery quality and incidence of adverse events were recorded. Groups were compared using parametric analysis of variance and nonparametric (Kruskal-Wallis, Chi-square, Fisher’s exact) tests as appropriate, p < 0.05.ResultsMidazolam significantly reduced alfaxalone induction and maintenance doses (46%; p = 0.034 and 32%, p = 0.012, respectively), whereas ketamine only reduced the alfaxalone induction dose (30%; p = 0.010). Recovery quality was unacceptable in nine dogs in group A, three dogs in group AK and three dogs in group AM.Conclusions and clinical relevanceMidazolam, but not ketamine, reduced the alfaxalone infusion rate, and both co-adjuvant drugs reduced the alfaxalone induction dose. Alfaxalone TIVA allowed anaesthetic maintenance for dental procedures in dogs, but the quality of anaesthetic recovery remained unacceptable irrespective of its combination with ketamine or midazolam.  相似文献   

6.
The pharmacological effects of the anesthetic alfaxalone were evaluated after intramuscular (IM) administration to 6 healthy beagle dogs. The dogs received three IM doses each of alfaxalone at increasing dose rates of 5 mg/kg (IM5), 7.5 mg/kg (IM7.5) and 10 mg/kg (IM10) every other day. Anesthetic effect was subjectively evaluated by using an ordinal scoring system to determine the degree of neuro-depression and the quality of anesthetic induction and recovery from anesthesia. Cardiorespiratory variables were measured using noninvasive methods. Alfaxalone administered IM produced dose-dependent neuro-depression and lateral recumbency (i.e., 36 ± 28 min, 87 ± 26 min and 115 ± 29 min after the IM5, IM7.5 and IM10 treatments, respectively). The endotracheal tube was tolerated in all dogs for 46 ± 20 and 58 ± 21 min after the IM7.5 and IM10 treatments, respectively. It was not possible to place endotracheal tubes in 5 of the 6 dogs after the IM5 treatment. Most cardiorespiratory variables remained within clinically acceptable ranges, but hypoxemia was observed by pulse oximetry for 5 to 10 min in 2 dogs receiving the IM10 treatment. Dose-dependent decreases in rectal temperature, respiratory rate and arterial blood pressure also occurred. The quality of recovery was considered satisfactory in all dogs receiving each treatment; all the dog exhibited transient muscular tremors and staggering gait. In conclusion, IM alfaxalone produced a dose-dependent anesthetic effect with relatively mild cardiorespiratory depression in dogs. However, hypoxemia may occur at higher IM doses of alfaxalone.  相似文献   

7.
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8.
A total of 103 anaesthetic inductions were performed in horses for a variety of elective procedures. All cases were premedicated with acepromazine maleate (0.02 to 0.05 mg/kg body weight [bwt] intramuscularly [im]). In 50 cases (Group A) anaesthesia was induced by a single intravenous (iv) bolus of thiopentone sodium (11.1 mg/kg bwt or 1 g/90 kg bwt) followed immediately by a bolus of suxamethonium chloride (0.1 mg/kg bwt). In 53 cases (Group B) anaesthesia was induced using iv guaiacol glycerine ether (GGE) (approximately 50 mg/kg bwt) followed by a bolus of thiopentone at half the usual dose rate (5.6 mg/kg bwt or 1 g/180 kg bwt). Induction of anaesthesia was uneventful in both groups although in Group B it was particularly smooth. Following endotracheal intubation anaesthesia was maintained with halothane in oxygen administered via a circle system. The duration of anaesthesia was comparable between the two groups; however, the mean (+/- sd) time to standing in Group B, 35 +/- 22 mins, was significantly shorter than in Group A, 48 +/- 25 mins. The use of the GGE/thiopentone technique is discussed.  相似文献   

9.
ObjectiveTo compare the effects of intravenous (IV) lidocaine and fentanyl on the cough reflex and autonomic response during endotracheal intubation in dogs.Study designRandomized, blinded, superiority clinical trial.AnimalsA total of 46 client-owned dogs undergoing magnetic resonance imaging.MethodsAfter intramuscular methadone (0.2 mg kg–1), dogs were randomized to be administered either IV lidocaine (2 mg kg–1; group L) or fentanyl (7 μg kg–1; group F). After 5 minutes, alfaxalone was administered until endotracheal intubation was possible (1 mg kg–1 IV over 40 seconds followed by 0.4 mg kg–1 increments to effect). Total dose of alfaxalone was recorded and cough reflex at endotracheal intubation was scored. Heart rate (HR) was continuously recorded, Doppler systolic arterial blood pressure (SAP) was measured every 20 seconds. Vasovagal tonus index (VVTI) and changes (Δ) in HR, SAP and VVTI between pre-intubation and intubation were calculated. Groups were compared using univariate and multivariate analysis. Statistical significance was set as p < 0.05.ResultsGroup F included 22 dogs and group L 24 dogs. The mean (± standard deviation) alfaxalone dose was 1.1 (± 0.2) and 1.35 (± 0.3) mg kg–1 in groups F and L, respectively (p = 0.0008). At intubation, cough was more likely in group L (odds ratio = 11.3; 95% confidence intervals, 2.1 – 94.2; p = 0.01) and HR increased in 87.5% and 54.5% of groups L and F, respectively (p = 0.02). The median (range) ΔHR between pre-intubation and intubation was higher (13.1%; – 4.3 to + 55.1) in group L (p = 0.0021). Between groups, SAP and VVTI were similar.Conclusion and clinical relevanceAt the stated doses, whilst reducing the alfaxalone dose, fentanyl is superior to lidocaine in suppressing the cough reflex and blunting the increase in HR at endotracheal intubation in dogs premedicated with methadone.  相似文献   

10.
OBJECTIVE: To investigate the onset and duration of neuromuscular blockade of rocuronium bromide and its associated haemodynamic effects at three doses in healthy horses. STUDY DESIGN: Prospective, randomized experimental study. ANIMALS: Seven adult horses aged 3-20 (mean 10.3) years and weighing 466 +/- 44 (mean +/- SD) kg. METHODS: Horses were anaesthetized three times with at least 2 weeks between. They were pre-medicated with 0.6 mg kg(-1) xylazine and 0.01 mg kg(-1) butorphanol i.v.. Anaesthesia was induced with 2.2 mg kg(-1) ketamine and 0.1 mg kg(-1) diazepam i.v.. Following orotracheal intubation anaesthesia was maintained with isoflurane in 100% oxygen. Intermittent positive pressure ventilation was initiated and the horses were ventilated at a respiratory rate (fr) of 4-8 breaths minute(-1). Neuromuscular function was monitored with an acceleromyograph. The peroneal nerve was stimulated with train-of-four (TOF) mode at 2 Hz every 15 seconds. Each horse received, in randomly assigned order, one of the three doses of rocuronium: 0.2 mg kg(-1) (D02), 0.4 mg kg(-1) (D04) or 0.6 mg kg(-1) (D06) i.v.. Lag time, onset time, time of no response, duration of action and the TOF ratio 0.7 and 0.9 were measured. Recovery time (T1(25-75)) was calculated. Vital parameters were recorded at 5-minute intervals on a standard anaesthetic record form. RESULTS: Rocuronium produced a dose-dependent duration of action in isoflurane-anaesthetized horses. 100% block was observed in D04 and D06 but not in D02, in which the maximum decrease of the first twitch of TOF attained was 91.5 +/- 16.5%. Time to T1(25) was 13.1 +/- 5.5 minutes, 38.6 +/- 10.1 minutes and 55 +/- 9.8 minutes in D02, D04 and D06 respectively. There was a significantly shorter time for TOFR 0.9 with 0.2 mg kg(-1) compared with 0.4 and 0.6 mg kg(-1) rocuronium. T1(25-75) in D04 and D6 was not statistically significantly different. Heart rate, systolic, diastolic and mean arterial blood pressure increased slightly during the observation period. CONCLUSION: Rocuronium is an effective nondepolarizing muscle relaxant in horses under isoflurane anaesthesia. It had a dose-dependent onset and duration of action. Rocuronium did not produce significant changes in the measured cardiovascular parameters.  相似文献   

11.
OBJECTIVE: To investigate alterations in peri-operative body temperatures and oesophageal-skin temperatures in isoflurane-anaesthetized rabbits following either ketamine-midazolam or ketamine-medetomidine induction of anaesthesia. ANIMAL POPULATION: Fifty client-owned rabbits, (25 male, 25 female) of different breeds anaesthetized for elective neutering (age range: 3-42 months; mass range: 1.15-4.3 kg). STUDY DESIGN: Randomized, blinded clinical study. METHODS: Pre-anaesthetic rectal temperature was measured. A 24 SWG catheter was placed in a marginal ear vein after local anaesthesia. Ketamine (15 mg kg(-1)) with medetomidine (0.25 mg kg(-1)) (group KMT) or with midazolam (3 mg kg(-1)) (group KMZ) was injected intramuscularly (IM). Following endotracheal intubation anaesthesia was maintained with isoflurane in oxygen. Carprofen (3 mg kg(-1)) and glucose saline (5 mL kg(-1) hour(-1)) were administered through the intravenous catheter. Room temperature and humidity, skin temperature (from tip of pinna) and oesophageal temperature were measured during anaesthesia. Ovariohysterectomy or castration was performed. Rectal temperature was taken when isoflurane was discontinued (time zero) and 30, 60 and 120 minutes thereafter. Atipamezole (0.5 mg kg(-1)) was administered IM to rabbits in group KMT at zero plus 30 minutes. Mass, averaged room temperature and duration of anaesthesia data were compared using a two-tailed t-test. Age, averaged room humidity, rectal temperature decrease, oesophageal temperature decrease and oesophageal-skin difference data were compared using a Kruskal-Wallis test. p < 0.05 was considered significant. RESULTS: The averaged oesophageal-skin temperature difference was significantly greater in group KMT [median 9.85 degrees C (range 6.42-13.85 degrees C)] than in group KMZ [4.38 degrees C (2.83-10.43 degrees C)]. Rectal temperature decreased over the anaesthetic period was not significantly different between the two groups; however, oesophageal temperature decrease was significantly less in group KMT [1.1 degrees C (-0.1-+2.7 degrees C)] than in group KMZ [1.4 degrees C (0.6-3.1 degrees C)]. CONCLUSIONS: Oesophageal-skin temperature difference is larger in rabbits anaesthetized with ketamine-medetomidine combination than ketamine-midazolam. CLINICAL RELEVANCE: The oesophageal temperature in rabbits anaesthetized with ketamine-medetomidine and isoflurane decreases significantly less than in animals anaesthetized with ketamine-midazolam and isoflurane, during anaesthesia.  相似文献   

12.
Propofol formulated in a mixed medium-chain and long-chain triglycerides emulsion has been recently introduced for clinical use as an alternative to the conventional long-chain triglycerides formulation. This prospective multicentric study evaluated the clinical effectiveness and the complications associated with the use of this new formulation of propofol in dogs. Forty-six Spanish veterinary clinics participated in this study. A total of 541 anaesthesias (118 ASA I, 290 ASA II, 101 ASA III and 32 ASA IV) performed for various diagnostic and therapeutic purposes were evaluated. The anaesthetic protocol was not controlled, with the exception that propofol had to be used at least for induction of anaesthesia. The induction dose of propofol and the incidence of anaesthetic complications throughout the procedure were recorded. A chi-square test compared the incidence of complications according to the maintenance agent used (propofol vs. inhalatory anaesthesia), anaesthetic risk (ASA classification) and the reason for the anaesthesia. The patients premedicated with alpha2 agonists needed lower doses (mean +/- SD, 2.9 +/- 1.3 mg/kg i.v.) than the animals premedicated with phenothiazines (3.9 +/- 1.4 mg/kg i.v.) or benzodiazepines (4.0 +/- 1.4 mg/kg i.v.). The most frequent complications were difficult endotracheal intubation (1.3%), postinduction apnoea (11.3%), cyanosis (0.6%), bradypnoea (2.6%), tachypnoea (2.8%), bradycardia (2%), tachycardia (2.6%), hypotension (0.2%), shock (0.2%), vomiting (4.6%), epileptiform seizures (2.8%), premature awakening (7.4%) and delayed recovery (0.9%). There were no cases of pain on injection or aspiration pneumonia. Three dogs died (0.55%), one during induction and two during recovery from anaesthesia. This study demonstrates that the new formulation of propofol is an useful and effective drug to induce general anaesthesia in dogs.  相似文献   

13.
Pharmacokinetics of difloxacin, a fluoroquinolone antibiotic, was determined in pigs and broilers after intravenous (i.v.), intramuscular (i.m.), or oral (p.o.) administration at a single dose of five (pigs) or 10 mg/kg (broilers). Plasma concentration profiles were analyzed by a compartmental pharmacokinetic method. Following i.v., i.m. and p.o. doses, the elimination half-lives (t(1/2beta)) were 17.14 +/- 4.14, 25.79 +/- 8.10, 16.67 +/- 4.04 (pigs) and 6.11 +/- 1.50, 5.64 +/- 0.74, 8.20 +/- 3.12 h (broilers), respectively. After single i.m. and p.o. administration, difloxacin was rapidly absorbed, with peak plasma concentrations (C(max)) of 1.77 +/- 0.66, 2.29 +/- 0.85 (pigs) and 2.51 +/- 0.36, 1.00 +/- 0.21 microg/mL (broilers) attained at t(max) of 1.29 +/- 0.26, 1.41 +/- 0.88 (pigs) and 0.86 +/- 0.4, 4.34 +/- 2.40 h (broilers), respectively. Bioavailabilities (F) were (95.3 +/- 28.9)% and (105.7 +/- 37.1)% (pigs) and (77.0 +/- 11.8)% and (54.2 +/- 12.6)% (broilers) after i.m. and p.o. doses, respectively. Apparent distribution volumes(V(d(area))) of 4.91 +/- 1.88 and 3.10 +/- 0.67 L/kg and total body clearances(Cl(B)) of 0.20 +/- 0.06 and 0.37 +/- 0.10 L/kg/h were determined in pigs and broilers, respectively. Areas under the curve (AUC), the half-lives of both absorption and distribution(t(1/2ka), t(1/2alpha)) were also determined. Based on the single-dose pharmacokinetic parameters determined, multiple dosage regimens were recommended as: a dosage of 5 mg/kg given intramuscularly every 24 h in pigs, or administered orally every 24 h at the dosage of 10 mg/kg in broilers, can maintain effective plasma concentrations with bacteria infections, in which MIC(90) are <0.25 microg/mL and <0.1 microg/mL respectively.  相似文献   

14.
OBJECTIVE: To compare ketamine-midazolam (KMZ) and ketamine-medetomidine (KMT) anaesthesia in rabbits using anaesthetic induction, maintenance and recovery data. STUDY DESIGN: Randomized, prospective, blinded clinical trial. ANIMALS: Fifty rabbits (25 male, 25 female) of different breeds undergoing ovariohysterectomy or castration. Rabbits were 12.7 +/- 9.8 months old with body mass 2.24 +/- 0.61 kg. STUDY DESIGN: Randomized, prospective, blinded clinical trial. METHODS: Ketamine (15 mg kg(-1)) and midazolam (3 mg kg(-1)) or medetomidine (0.25 mg kg(-1)) were administered by intramuscular (IM) injection. Ten minutes after IM injection, blind intubation of the trachea was attempted. The time taken, the number of attempts and a subjective score of the ease of intubation were recorded. Isoflurane (range 0-3.6%) in 100% oxygen was delivered via a Jackson Rees modification of an Ayre's T-piece non-rebreathing system. Carprofen (3 mg kg(-1)) and dextrose saline (5 mL kg(-1) hour(-1)) were administered intravenously (IV). During surgery heart rate (HR), respiratory rate (RR) and arterial oxygen saturation of haemoglobin (SpO(2)) were monitored. Times to extubation and first head lift were recorded. Group KMT received atipamezole (0.5 mg kg(-1)) IM 30 minutes after discontinuation of isoflurane. Activity was scored at 30, 60 and 120 minutes after volatile agent discontinuation. Mean time to loss of righting reflex (LRR), body mass, RR and vaporizer setting were compared using a two-tailed t-test. Median values for all other data were compared using a Mann-Whitney test. RESULTS: Mean time to LRR (+/-SD) was significantly shorter with KMT (1.64 +/- 0.55 minutes) compared with KMZ (2.28 +/- 0.66 minutes). Intubation was not possible in seven rabbits (three with KMT, four with KMZ) and three with KMT developed laryngospasm. Mean HR, SpO(2) and vaporizer settings were all significantly lower in group KMT. CONCLUSION AND CLINICAL RELEVANCE: KMT has a faster onset of action and a greater isoflurane-sparing effect when compared with KMZ. Rabbits with KMT were more prone to laryngospasm and had significantly lower HR.  相似文献   

15.
ObjectiveTo characterise four different intramuscular (IM) anaesthetic protocols, two with alfaxalone and two with alfaxalone in combination with medetomidine in terrestrial tortoises.Study designBlinded, randomized, cross‐over experimental study.AnimalsNine healthy adult male Horsfield's tortoises (Agrionemys horsfieldii).MethodsEach tortoise was randomly assigned to one of four different protocols: 1) 10 mg kg?1 alfaxalone; 2) 10 mg kg?1 alfaxalone + 0.10 mg kg?1 medetomidine; 3) 20 mg kg?1 alfaxalone; and 4) 20 mg kg?1 alfaxalone + 0.05 mg kg?1 medetomidine. During the experiment, the following variables were recorded: heart rate; respiratory rate; peripheral nociceptive responses; muscle strength; ability to intubate; palpebral, corneal and tap reflexes; and cloacal temperature.ResultsProtocols 1 and 2 resulted in moderate sedation with no analgesia, and moderate to deep sedation with minimal analgesia, respectively. Protocols 3 and 4 resulted in deep sedation or anaesthesia with variable analgesic effect; these two protocols had the longest total anaesthetic time and allowed intubation in 6/9 and 8/9 tortoises respectively. The total anaesthesia/sedation time produced by alfaxalone was significantly increased (p <0.05) by the addition of medetomidine. There were no significant differences regarding time to plateau phase and duration of plateau phase. Baseline heart rate of 53 ± 6 beats minute?1 decreased significantly (p <0.05) with all protocols, and was lower (p <0.05) in protocols 3 and 4. Heart rate increased after atipamezole administration, but the increase was transient. In two tortoises, extreme bradycardia with no cardiac activity for 10 minutes was observed with protocols 3 and 4.Conclusion and clinical relevanceAlfaxalone 10 and 20 mg kg?1 IM can be used for sedation for non‐painful procedures. Alfaxalone in combination with medetomidine can be used for deeper sedation or anaesthesia, but the observed respiratory and cardiovascular depression may limit its use.  相似文献   

16.
OBJECTIVE: To study the effects of morphine on haemodynamic variables, blood gas values and the requirement for additional anaesthetic drugs in horses undergoing surgery. STUDY DESIGN: Prospective randomized study. METHODS: Thirty-eight client-owned horses, ASA(American Society of Anesthesiologists) category I or II, undergoing elective surgical procedures, were studied. Horses were divided between two groups, and were paired according to operation, anaesthetist, body position during surgery, mass and breed. Group M+ received morphine by intravenous (IV) injection (0.15 mg kg(-1)) before induction of anaesthesia and then by infusion (0.1 mg kg(-1) hour(-1)) throughout anaesthesia. Group M- received the same anaesthetic technique (pre-anaesthetic medication with romifidine (100 microg kg(-1)) IV; induction with ketamine (2.2 mg kg(-1)) and diazepam (50 microg kg(-1)) IV; maintenance with halothane), except that morphine was excluded. Both groups received flunixin IV (1.1 mg kg(-1)) before surgery. Both groups also received 50% nitrous oxide for the first 10 minutes of anaesthesia. During anaesthesia, end-tidal halothane was maintained at 0.9% (+/-0.1%) in both groups. Heart rate (HR) and respiratory rate (fr), systolic, mean and diastolic arterial pressures were recorded every 5 minutes. Arterial blood samples were analysed every 20 minutes. Additional anaesthetics (ketamine and midazolam) were administered whenever the horse moved. Dobutamine was infused to maintain mean arterial pressure (MAP) > 58 mm Hg, but was discontinued when MAP reached 68 mm Hg. Mechanical ventilation was imposed when PaCO(2) exceeded 9.3 kPa (70 mm Hg). RESULTS: Haemodynamic data (HR and MAP) and blood gas measurements were analysed using repeated measure analysis using a mixed covariance pattern model (SAS version 8.2). A Student's t-test was used to investigate differences between groups in the doses of additional anaesthetics required. There were no significant differences between M+ or M- groups in MAP (p = 0.65), HR (p = 0.74), PaO2 (p = 0.40) or PaCO2 (p = 0.20). Fewer horses in the M+ group received additional anaesthetics (15.8% compared to 21.1% in M- group), and the mean dose of ketamine required was higher in the M- group (mean +/- SD: M-, 0.93 +/- 0.70; M+, 0.45 +/- 0.17). These differences were not statistically significant (p = 0.28). CONCLUSIONS: Pre-anaesthetic and peri-operative morphine administration is not associated with significant haemodynamic or ventilatory changes. Horses receiving morphine tended to receive fewer and lower doses of additional anaesthetic drugs, although this was not statistically significant.  相似文献   

17.
ObjectiveTo determine the minimum infusion rate (MIR) of alfaxalone required to prevent purposeful movement of the extremities in response to noxious stimulation.Study DesignProspective, experimental.AnimalsEight healthy goats; four does and four wethers.MethodsAnaesthesia was induced with alfaxalone 3 mg kg−1 intravenously (IV). A continuous IV infusion of alfaxalone, initially at 0.2 mg kg−1 minute−1, was initiated. Following endotracheal intubation the goats breathed spontaneously via a circle breathing circuit delivering supplementary oxygen. The initial infusion rate was maintained for 30 minutes before testing for responses. The stimulus was clamping on the proximal (soft) part of one digit of the hoof with Vulsellum forceps for 60 seconds. In the absence or presence of purposeful movement of the extremities, the infusion rate was reduced or increased by 0.02 mg kg−1 minute−1 and held constant for 30 minutes before claw-clamping again. Alfaxalone MIR was calculated as the mean of the infusion rates that allowed and abolished movement. Cardio-respiratory parameters were measured. Recovery from general anaesthesia was timed and quality scored. Results are presented as median (range).ResultsThe MIR of alfaxalone was 0.16 (0.14–0.18) mg kg−1 minute−1 or 9.6 (8.4–10.8) mg kg−1 hour−1. Induction of and recovery from anaesthesia were excitement-free. Cardio-respiratory changes were minimal, although compared to baseline HR increased, and at 2 minutes post-induction, (prior to oxygen supplementation), PaO2 decreased significantly from 84 (80–88) to 70 (51–72) mmHg [11.2 (10.7–11.7) to 9.3 (6.8–9.6) kPa]. Sporadic muscle twitches, unrelated to depth of anaesthesia, were observed during the period of general anaesthesia. Time (minutes) to sternal recumbency and standing were 4.0 (3.0–10.0) and 41.5 (25.0–57.0) respectively.Conclusions and Clinical RelevanceAlfaxalone can be used for total intravenous anaesthesia (TIVA) in goats and is associated with minimal adverse effects. Oxygen supplementation is advised, especially when working at higher altitudes.  相似文献   

18.
A study on bioavailability and pharmacokinetics of florfenicol was conducted in 20 crossbred healthy sheep following a single intravenous (i.v.) and intramuscular (i.m.) doses of 20 and 30 mg/kg body weight (b.w.). Florfenicol concentrations in serum were determined by a validated high-performance liquid chromatography method with UV detection at a wavelength of 223 nm in which serum samples were spiked with chloramphenicol as internal standard. Serum concentration-time data after i.v. administration were best described by a three-compartment open model with values for the distribution half-lives (T(1/2alpha)) 1.51 +/- 0.06 and 1.59 +/- 0.10 h, elimination half-lives (T(1/2beta)) 18.83 +/- 6.76 and 18.71 +/- 1.85 h, total body clearance (Cl(B)) 0.26 +/- 0.03 and 0.25 +/- 0.01 L/kg/h, volume of distribution at steady-state (V(d(ss))) 1.86 +/- 0.11 and 1.71 +/- 0.20 L/kg, area under curve (AUC) 76.31 +/- 9.17 and 119.21 +/- 2.05 microg.h/mL after i.v. injections of 20 and 30 mg/kg b.w. respectively. Serum concentration-time data after i.m. administration were adequately described by a one-compartment open model. The pharmacokinetic parameters were distribution half-lives (T(1/2k(a) )) 0.27 +/- 0.03 and 0.25 +/- 0.09 h, elimination half-lives (T(1/2k(e) )) 10.34 +/- 1.11 and 9.57 +/- 2.84 h, maximum concentrations (C(max)) 4.13 +/- 0.29 and 7.04 +/- 1.61 microg/mL, area under curve (AUC) 67.95 +/- 9.61 and 101.95 +/- 8.92 microg.h/mL, bioavailability (F) 89.04% and 85.52% after i.m. injections of 20 and 30 mg/kg b.w. respectively.  相似文献   

19.
OBJECTIVE: The purpose of this study was to evaluate globe position, muscle relaxation and changes in ventilatory parameters after intravenous administration of 0.1 mg/kg rocuronium. STUDY DESIGN: Prospective clinical study. ANIMAL STUDIED: Sixteen dogs of different breeds, with a body weight of 22.1 +/- 13 kg and age of 5.6 +/- 2.8 years (mean +/- SD), were anesthetized for a short ophthalmic examination requiring central position of the globe. PROCEDURES: All dogs were premedicated with 0.005 mg/kg medetomidine and 0.1 mg/kg methadone IV. Anesthesia was induced with propofol to effect and maintained with 10 mg/kg/h propofol by continuous rate infusion. Following endotracheal intubation all dogs breathed 100% oxygen via an anesthetic circle system. Neuromuscular function was assessed with an acceleromyograph (TOF-Guard, Organon Teknika NV, Turnhout, Belgium) and by stimulation of the nervus peroneus superficialis. The ventilation parameters were measured using spirometry and capnography. After baseline measurements 0.1 mg/kg rocuronium was administered IV. Minute volume (MV), tidal volume (Vt), respiratory rate (RR), end expiratory carbon dioxide concentration (PE'CO(2)) and maximal depression of the response of the first twitch (T1) of train-of-four (TOF) stimulation and train-of-four ratio (TOFR) was measured. The change in the position of the globe was recorded. RESULTS: T1 decreased to 61 +/- 18% and the TOF ratio to 45 +/- 21% of baseline values. Both parameters returned to baseline after 9 min. There was no significant reduction in MV, TV and RR and no increase in PE'CO(2). The globe rotated to a central position of 45 +/- 7.7 s after administration of rocuronium and remained there for 23 +/- 10.8 min in all dogs. CONCLUSION: Rocuronium administered intravenously at a dose of 0.1 mg/kg to dogs causes a central position of the globe but minimal impairment of ventilation parameters.  相似文献   

20.
The objective of this paper was to evaluate the effect of constant rate infusion of medetomidine on the anaesthetic requirements of desflurane in dogs. For this, six healthy dogs were studied. Measurements for baseline were taken in the awake, unsedated dogs, then each dog received intravenously (i.v.) three anaesthetic protocols: M (no medetomidine infusion), M0.5 (infusion of medetomidine at 0.5 microg/kg/h, i.v.) or M1 (infusion of medetomidine at 1 microg/kg/h, i.v.). All dogs were sedated with medetomidine (2 microg/kg, i.v.) and measurements repeated in 10 min. Induction of anaesthesia was delivered with propofol (3 mg/kg, i.v.) and maintained with desflurane for 90 min to achieve a defined surgical plane of anaesthesia in all cases. After tracheal intubation infusion of medetomidine was initiated and maintained until the end of anaesthesia. Cardiovascular, respiratory, arterial pH (pHa) and arterial blood gas tensions (PaO(2), PaCO(2)) variables were measured during the procedure. End tidal desflurane concentration (EtDES) was recorded throughout anaesthesia. Time to extubation, time to sternal recumbency and time to standing were also noted. Heart rate and respiratory rate were significantly decreased during sedation in all protocols compared to baseline values. Mean heart rate, mean arterial pressure, systolic arterial pressure, diastolic arterial pressure, respiratory rate, tidal volume, arterial oxygen saturation, end-tidal CO(2), pHa, PaO(2), and PaCO(2) during anaesthesia were similar for all protocols. EtDES for M (8.6 +/- 0.8%) was statistically higher than for M0.5 (7.6 +/- 0.5%) and M1 (7.3 +/- 0.7%) protocols. Infusion of medetomidine reduces desflurane concentration required to maintain anaesthesia in dogs.  相似文献   

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