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1.
Aline M. Ambrosio Tatiana P.A. Carvalho-Kamakura Keila K. Ida Barbara Varela Felipe S.R.M. Andrade Lara L. Facó Denise T. Fantoni 《Veterinary anaesthesia and analgesia》2017,44(2):254-263
Objective
To examine the intrapulmonary gas distribution of low and high tidal volumes (VT) and to investigate whether this is altered by an alveolar recruitment maneuver (ARM) and 5 cmH2O positive end-expiratory pressure (PEEP) during anesthesia.Study design
Prospective randomized clinical study.Animals
Fourteen client-owned bitches weighing 26 ± 7 kg undergoing elective ovariohysterectomy.Methods
Isoflurane-anesthetized dogs in dorsal recumbency were ventilated with 0 cmH2O PEEP and pressure-controlled ventilation by adjusting the peak inspiratory pressure (PIP) to achieve a low (7 mL kg?1; n = 7) or a high (12 mL kg?1; n = 7) VT. Ninety minutes after induction (T90), an ARM (PIP 20 cmH2O for 10 seconds, twice with a 10 second interval) was performed followed by the application of 5 cmH2O PEEP for 35 minutes (RM35). The vertical (ventral=0%; dorsal=100%) and horizontal (right=0%; left=100%) center of ventilation (CoV), four regions of interest (ROI) (ventral, central-ventral, central-dorsal, dorsal) identified in electrical impedance tomography images, and cardiopulmonary data were analyzed using two-way repeated measures anova.Results
The low VT was centered in more ventral (nondependent) areas compared with high VT at T90 (CoV: 38.8 ± 2.5% versus 44.6 ± 7.2%; p = 0.0325). The ARM and PEEP shifted the CoV towards dorsal (dependent) areas only during high VT (50.5 ± 7.9% versus 41.1 ± 2.8% during low VT, p = 0.0108), which was more distributed to the central-dorsal ROI compared with low VT (p = 0.0046). The horizontal CoV was centrally distributed and cardiovascular variables remained unchanged throughout regardless of the VT, ARM, and PEEP.Conclusions and clinical relevance
Both low and high VT were poorly distributed to dorsal dependent regions, where ventilation was improved following the current ARM and PEEP only during high VT. Studies on the role of high VT on pulmonary complications are required. 相似文献2.
Alexandru Tutunaru Julien Dupont Vincent Huberty Mostafa Ibrahim Didier Serteyn Charlotte Sandersen 《Veterinary anaesthesia and analgesia》2017,44(4):910-914
Objective
To determine the dose of cis-atracurium needed to produce a moderate neuromuscular blockade (NMB) in pigs.Study design
Prospective experimental study.Animals
Seven pigs [five females and two males; median (range) body weight: 47 (36–64) kg].Methods
Pigs were premedicated with intramuscular midazolam (0.3 mg kg?1) and ketamine (7 mg kg?1). Anaesthesia was induced with intravenous (IV) propofol 3 (1–4) mg kg?1 and maintained with isoflurane in oxygen. Based on a preliminary study, the subjects were administered 0.3 mg kg?1 cis-atracurium followed by 0.48 mg kg?1 hour?1 constant rate infusion (CRI) IV. A moderate NMB was defined as a train-of-four (TOF) count of ≤2 by acceleromyography. When the TOF count was >2, 0.1 mg kg?1 cis-atracurium was administered and the CRI was increased. The cis-atracurium CRI was decreased when the TOF count was under 2 for more than 15 minutes. The total dose of cis-atracurium required to maintain a moderate NMB was calculated as the total amount of cis-atracurium used (both CRI and supplementary boluses) divided by the administration time.Results
The cis-atracurium CRI lasted for 87 (76–151) minutes. To induce and maintain a moderate neuromuscular blockade, the initial dose of cis-atracurium was 0.3 (0.3– 0.5) mg kg?1 and the CRI was 0.71 (0.37–0.98) mg kg?1 hour?1.Conclusions and clinical relevance
The doses described in our study may help researchers obtain a moderate NMB using cis-atracurium in pigs. 相似文献3.
Objective
To describe a transorbital approach to the maxillary nerve block in dogs and compare it with a traditional approach.Study design
Prospective, randomized controlled study.Animals
Heads from 17 euthanized dogs (10 Greyhounds, three Border Collies and four of mixed breed).Methods
A volume of 1 mL of methylene blue dye was injected by each of two techniques, a traditional percutaneous approach and a transorbital approach to the maxillary nerve block. Both techniques were used on each head, alternating the left and right sides after random assignment to the first head. The heads were dissected to reveal the maxillary nerve and the length of nerve stained was measured.Results
There was no significant difference (p = 0.67) in the proportion of nerves stained for a length >6 mm by either technique (88.2% transorbital versus 82.3% percutaneous). The mean length of nerve stained did not differ significantly between the techniques (p = 0.26).Conclusions and clinical relevance
The transorbital approach to the maxillary nerve block described here presents a viable alternative to the traditional percutaneous approach. Further study is required to confirm its efficacy and safety under clinical conditions. 相似文献4.
Preet M. Singh Katherine Reid Ravindra Gaddam Madhav Bhatia Stefan Smith Antony Jacob Paul Chambers 《Veterinary anaesthesia and analgesia》2017,44(5):1149-1155
Objective
To determine the anti-inflammatory efficacy of choline in vivo and in vitro and to investigate the anti-inflammatory mechanisms of choline.Study design
Randomized, controlled studies.Animals
In vivo trials used 16 Romney sheep. In vitro experiments utilized RAW 264.7 mouse macrophage cells.Methods
Hypoxaemia induced in 16 sheep by intravenous (IV) injection of 50 μg kg–1 xylazine, an α-2 agonist, was measured in sheep at 0, 1 and 4 minutes using arterial blood gas analysis with and without 50 mg kg–1 IV choline chloride premedication. Cell culture studies used enzyme-linked immunosorbent assay to measure the release of tumour necrosis factor (TNF-α) from lipopolysaccharide (LPS) stimulated macrophages with and without choline chloride premedication. TNF-α release was compared to thalidomide suppressed and untreated cells.Results
Choline premedication in sheep mitigated a reduction in arterial partial pressure of oxygen (PaO2) but did not prevent development of clinically significant hypoxaemia. Decrease in mean PaO2 of choline treated sheep was 6.36 kPa (47.7 mmHg) compared to 9.81 kPa (73.6 mmHg) in control sheep. In vitro studies demonstrate that choline administered concurrent with LPS activation did not significantly suppress TNF-α expression but that treatment of cells with choline 10 minutes prior to LPS activation did significantly suppress TNF-α expression. Choline pretreated cells expressed 23.99 ± 4.52 ng mg–1 TNF-α while LPS only control cells expressed 33.83 ± 3.20 ng mg–1.Conclusions
Choline is able to prevent macrophage activation in vitro when administered prior to LPS activation and may reduce hypoxaemia in sheep developing pulmonary oedema after xylazine administration. This effect requires premedication with choline.Clinical relevance
Pharmacological manipulation of autonomic inflammatory responses holds promise for the treatment of inflammation. However, the complex cellular mechanisms involved in this reflex means that an adequate therapy should approach multiple pathways and mechanisms of the inflammatory response. 相似文献5.
Objectives
To determine the prevalence of mitral valve regurgitation (MR) in asymptomatic Swedish Norfolk terriers.Animals
Seventy-nine privately owned Norfolk terriers.Materials and methods
A prospective observational study was conducted where dogs were recruited via the Swedish Norfolk terrier club. All dogs were examined using the same protocol including physical examination and Doppler echocardiography.Results
Fifteen dogs (19%) had a murmur at the time of the examination. A total of 35 dogs (44%) had MR, including 23 dogs (29%) with both MR and tricuspid valve regurgitation and 12 dogs (15%) with MR only, identified on Doppler echocardiography. In addition, 7 dogs (9%) had tricuspid valve regurgitation only. The prevalence of MR increased with increasing age (p < 0.0001).Conclusions
Mitral valve regurgitation is common in asymptomatic Norfolk terriers with and without murmurs and the prevalence increases with age. The impact of MR in this breed on survival remains to be elucidated by a longitudinal study. 相似文献6.
Marja R. Raekallio Marika Virtanen Irmeli Happonen Outi M. Vainio 《Veterinary anaesthesia and analgesia》2017,44(4):803-810
Objective
To describe suspected adverse drug reactions in cats associated with use of α2-adrenoceptor agonists.Study design
Retrospective study.Animals
A total of 90 cats.Methods
Data were collected from reports on adverse reactions to veterinary medicines sent to the Finnish Medicines Agency during 2003–2013. All reports of suspected adverse reactions associated with use of α2-adrenoceptor agonists in cats were included. Probable pulmonary oedema was diagnosed based on post mortem or radiological examination, or presence of frothy or excess fluid from the nostrils or trachea. If only dyspnoea and crackles on auscultation were reported, possible pulmonary oedema was presumed.Results
Pulmonary oedema was suspected in 61 cases. Of these cats, 37 were categorised as probable and 24 as possible pulmonary oedema. The first clinical signs had been noted between 1 minute and 2 days (median, 15 minutes) after α2-adrenoceptor agonist administration. Many cats probably had no intravenous overhydration when the first clinical signs were detected, as either they presumably had no intravenous cannula or the signs appeared before, during or immediately after cannulation. Of the 61 cats, 43 survived, 14 died and for four the outcome was not clearly stated.Conclusions and clinical relevance
Pulmonary oedema is a perilous condition that may appear within minutes of an intramuscular administration of sedative or anaesthetic agent in cats. The symptoms were not caused by intravenous overhydration, at least in cats having no venous cannula when the first clinical signs were detected. 相似文献7.
Objectives
To determine whether the Enterprise point-of-care blood analysis system (EPOC) produces results in agreement with two other blood gas analysers in regular clinical use (i-STAT and Radiometer ABL77) and to investigate the precision of the new machine when used with equine whole blood.Study design
Prospective, randomized, non-blinded, comparative laboratory analyser study.Animals
Horses admitted to a university teaching hospital requiring arterial or venous blood gas analysis as part of their routine clinical management.Methods
One hundred equine blood samples were run immediately, consecutively and in randomized order on three blood gas analysers. Results of variables common to all three analysers were tested for agreement and compared with guidelines used in human medicine. These require 80% of results from the test analyser to fall within a defined range or percentage of results from the comparator devices to achieve acceptability. Additionally, 21 samples were run twice in quick succession on the EPOC analyser to investigate precision.Results
Agreement targets were not met for haematocrit, haemoglobin and base excess for either i-STAT or ABL77 analysers. EPOC precision targets were not met for partial pressure of carbon dioxide, ionized calcium, haematocrit and haemoglobin. Overall comparative performance of the EPOC was good to excellent for pH, oxygen tension, potassium, bicarbonate and oxygen saturation of haemoglobin, but marginal to poor for other parameters.Conclusions and clinical relevance
The EPOC may be useful in performing analysis of equine whole blood, but trend analysis of carbon dioxide tension, ionized calcium, haematocrit and haemoglobin should be interpreted with caution. The EPOC should not be used interchangeably with other blood gas analysers. 相似文献8.
Jenelle Izer Ronald Wilson Krista Hernon Akif Ündar 《Veterinary anaesthesia and analgesia》2017,44(1):133-137
Objective
To describe an ultrasound-guided approach for venous and arterial vascular access and catheterization in anesthetized adult Yorkshire cross-bred pigs.Study design
Prospective experimental study.Animals
Ten adult female Yorkshire cross-bred pigs, weighing 78.4 ± 5.6 kg (mean ± standard deviation).Methods
Using ultrasound guidance and the Seldinger technique, a 7 Fr, 20 cm triple-lumen central venous catheter was placed in the external jugular vein and an 18 gauge, 16 cm catheter was placed in the femoral artery. The success rate of catheterization and the incidence of catheter patency over 24 hours of general anesthesia were recorded.Results
Catheterization of the external jugular vein was successful in 10 out of 10 pigs and catheterization of the femoral artery was successful in eight out of 10 pigs. A surgical dissection technique on the femoral artery was performed in two pigs. Venous and arterial catheter patency was maintained in all pigs over the 24 hour study period.Conclusions and clinical relevance
Ultrasound guidance resulted in success rates of 100% for catheterization of the external jugular vein and 80% for catheterization of the femoral artery in anesthetized adult Yorkshire cross-bred pigs. This technique is a noninvasive, easily performed alternative to surgical exposure of the vessels in large pigs undergoing surgical instrumentation for biomedical device testing. 相似文献9.
E.T. Hostnik B.A. Scansen A.M. Habing G.A. Chiappone R.R. Layman R.D. White 《Journal of Veterinary Cardiology》2017,19(6):480-491
Introduction
Transthoracic echocardiography (TTE) is the primary tool for the assessment of cardiac structure and function in dogs but is challenging in English bulldogs due to dorsoventral compression of the thorax, obesity, and narrow intercostal spaces. Multi-detector computed tomography angiography (CTA) may overcome the conformational obstacles of cardiac imaging in this breed.Animals
Eleven client-owned English bulldogs.Materials and Methods
Prospective clinical trial with paired analysis of TTE and CTA studies.Results
Eight of the 25 linear cardiac dimensional measurements were significantly different between TTE and CTA (p<0.033). Intraobserver agreement was strong with average coefficients of variation (CV) of 5.34% for TTE and 2.50% for CTA. Interobserver agreement CV averaged 6.5% for TTE and 8.75% CTA. Ejection fraction, stroke volume, and end-systolic volume were significantly different between modalities (all p<0.002). No significant difference was present between end-diastolic volume for TTE compared with CTA.Discussion
High-quality cardiac angiographic studies were accomplished using CTA without the use of general anesthesia in English bulldogs. Multi-detector computed tomography angiography and TTE are not interchangeable modalities in the clinical setting.Conclusion
Multi-detector-CT ECG-gated cardiac angiography is possible in sedated, non-intubated English bulldogs. Differences were found between some cardiac dimensions as measured by TTE in the awake dog and compared with sedated CTA, indicating the two methodologies are not equivalent. Sedated, non-intubated CTA yielded high-quality imaging with strong intraobserver and interobserver measurement repeatability in English bulldogs. 相似文献10.
Anderson F. da Cunha Sara J. Ramos Michelle Domingues Amanda Shelby Hugues Beaufrère Rhett Stout Mark J. Acierno 《Veterinary anaesthesia and analgesia》2017,44(5):1068-1075
Objectives
1) To determine which peripheral artery commonly used for invasive arterial blood pressure (IBP) monitoring yields the least bias when compared with noninvasive blood pressure (NIBP) values obtained at the antebrachium of the dog, and 2) to identify and describe differences in systolic (SAP), mean (MAP) and diastolic arterial pressures (DAP) among different anatomical locations.Study design
Prospective experimental study.Animals
Twenty adult hound dogs weighing 24.5 ± 1.1 kg (mean ± standard deviation).Methods
Four peripheral arteries—dorsal pedal, median caudal, intermediate auricular and superficial palmar arteries—were catheterized with 20 gauge, 3.8 cm catheters. One NIBP cuff was placed in the middle third of the antebrachium. Four sets of IBP and NIBP measurements were simultaneously collected every 2 minutes. A linear mixed model was performed to analyze the collected data.Results
IBP values varied depending on the arterial catheterization site. The difference was greater for SAP. NIBP measured at the antebrachium had the best agreement with IBP measured at the median caudal artery.Conclusion and clinical relevance
IBP varies among anatomical locations. The smallest bias and narrowest limits of agreement were obtained at the median caudal artery, providing the best overall agreement with the equipment studied. The median caudal artery may be the preferable anatomical location for clinical comparison studies between IBP and NIBP in dogs when the cuff is on the antebrachium. 相似文献11.
Peter M. DiGeronimo Anderson F. da Cunha Bruno Pypendop João Brandão Rhett Stout Max Rinaldi Thomas N. Tully 《Veterinary anaesthesia and analgesia》2017,44(2):287-294
Objective
To determine the median effective dose (ED50) of intravenous (IV) bupivacaine associated with a 50% probability of causing clinically relevant cardiovascular effects [defined as 30% change in heart rate (HR) or mean arterial pressure (MAP)] in chickens anesthetized with isoflurane.Study design
Randomized up-and-down study.Animals
A total of 14 Ross-708 broiler chickens (Gallus gallus domesticus) weighing 1.70–2.75 kg.Methods
Anesthesia was induced and maintained with isoflurane. Monitoring included the electrocardiogram and invasive arterial pressures. Chickens were administered bupivacaine IV over 2 minutes using a dose based on the response of the previous animal. Dose was decreased when HR and/or MAP in the previous animal increased or decreased ≥30% after bupivacaine administration, or increased when HR or MAP changed <30%. The ED50 was defined as the dose resulting in ≥30% variation in HR or MAP in 50% of the population studied.Results
The IV ED50 of bupivacaine was 1.94 mg kg?1 using Dixon’s up-and-down method and 1.96 mg kg?1 by logistic regression.Conclusions and clinical relevance
These results suggest that 1.33 and 1.96 mg kg?1 of IV bupivacaine are associated with a respective 1 or 50% probability of a clinically significant change in MAP in isoflurane-anesthetized chickens. Identification of the cardiovascular changes associated with different doses of bupivacaine can be used as the basis for studies of therapeutic applications in the domestic chicken. Further studies are required to determine interspecies variation. 相似文献12.
Bruno H. Pypendop Juhana Honkavaara Jan E. Ilkiw 《Veterinary anaesthesia and analgesia》2017,44(1):52-62
Objective
To characterize the cardiovascular effects of dexmedetomidine, with or without MK-467, following intravenous (IV) administration in cats.Study design
Prospective Latin square experimental study.Animals
Six healthy adult purpose-bred cats.Methods
Cats were anesthetized with desflurane in oxygen for instrumentation with a carotid artery catheter and a thermodilution catheter in the pulmonary artery. One hour after discontinuation of desflurane, cats were administered dexmedetomidine (25 μg kg–1), MK-467 (600 μg kg–1), or dexmedetomidine (25 μg kg–1) and MK-467 (600 μg kg–1). All treatments were administered IV as a bolus. Cardiovascular variables were measured prior to drug administration and for 8 hours thereafter. Only data from the dexmedetomidine and dexmedetomidine–MK-467 treatments were analyzed.Results
Dexmedetomidine produced significant decreases in heart rate, cardiac index and right ventricular stroke work index, and significant increases in arterial blood pressure, central venous pressure, pulmonary artery pressure and systemic vascular resistance index. Dexmedetomidine combined with MK-467 resulted in significant but transient decrease in blood pressure and right ventricular stroke work index.Conclusion and clinical relevance
Following IV co-administration, MK-467 effectively attenuated dexmedetomidine-induced cardiovascular effects in cats. The drug combination resulted in transient reduction in arterial blood pressure, without causing hypotension. 相似文献13.
Background
False tendons (FTs) are string-like structures in the left ventricle. A FT might produce focal thickening at its insertion region of the left ventricle, which could be mistaken for focal hypertrophic cardiomyopathy.Objectives
To perform a prospective, echocardiographic follow-up examination of feline FTs and compare the wall thickness at the FT insertion region and a normal region without FTs at both examinations.Animals
One hundred twenty-eight cats with one or multiple FTs without other cardiac abnormalities or systemic disease.Methods
Measurements of the interventricular septum at end-diastole at a region with and without FT insertion were performed using two-dimensional echocardiography at both examinations and compared statistically using a Student's t-test.Results
The follow-up interval ranged from 5 to 110 months (mean, 33 months). Myocardial wall segments with FT insertions were significantly thicker compared with neighboring wall regions in the long axis, but not in the short-axis views obtained. Comparing the wall thickness of follow-up examinations with the initial examination, revealed a significant growth of both FT and non-FT segments. However, differences in growth between the FT region and region without FTs were not statistically different.Conclusions and clinical importance
Many normal cats have FTs, associated with focal thickening compared with neighboring regions. This thickening can increase over time, proportionate to growth in other (non-FT) segments. The association of such thickening with an FT and the absence of disproportionate growth in this segment over time suggests that these segments are simply thicker related to FT insertion. 相似文献14.
Jaime Viscasillas Richard Everson Emma Kate Mapletoft Charlotte Dawson 《Veterinary anaesthesia and analgesia》2019,46(2):246-250
Objective
To describe a novel ultrasound-guided posterior extraconal block in the dog.Study design
Prospective experimental cadaveric study.Animals
A total of 13 Beagle Cross cadaver heads.Methods
After describing the ultrasound bony landmarks and posterior extraconal local regional technique in one head, 12 heads were used to evaluate the spreading of contrast and evaluate potential complications. A 5–8 MHz microconvex ultrasound probe was positioned caudal to the orbital ligament, with the beam orientated transversely, and then tilted caudally until the orbital fissure was visualized. After identifying the bony structures consistent with the orbital fissure, a needle was advanced using an in-plane technique and 0.5 mL of a 50:50 mixture of iohexol and methylene blue was injected. Computed tomography (CT) and dissection were used to evaluate successful injections and potential complications. The injection was considered successful if radiopaque contrast medium was 5 mm from the orbital fissure. Potential complications were defined as the presence of radiopaque contrast within the globe or the intracalvarial tissues.Results
The CT images confirmed contrast at the target site in 15/24 (63%) of the injections. Only two injections were found in the temporalis muscle; the rest of the injections were located in the extraconal space. No potential complications such as intracranial spreading of contrast, intravascular or intraocular injection were found.Conclusions and clinical relevance
The technique can deliver contrast close to the main nerves which provide sensory and motor innervation to the eye. Further studies are needed to evaluate this technique in clinical cases. 相似文献15.
A. Al-Haidar N. Moula A. Leroux F. Farnir S. Deleuze C. Sandersen H. Amory 《Journal of Veterinary Cardiology》2017,19(6):492-501
Introduction
The aim of this study was to establish echocardiographic reference values for the equine species using allometric regression equations based on body weight (BW) and thoracic circumference (TC).Animals
A total of 239 horses or ponies were studied, including 65 warmbloods, 33 Standardbreds, 41 Thoroughbreds, 32 Arabian horses, 28 draft horses, and 40 ponies aged from 1 day to 30 years, weighing from 18 to 890 kg, with no evidence of cardiac disease.Methods
For each horse or pony, a two-dimensional and M-mode echocardiography was performed. Within each breed, the relationships between BW or TC and echocardiographic dimensions were examined using power regression equations. Predictions and their 95% prediction intervals were calculated for the echocardiographic measurements.Results
Within each breed, all echocardiographic measurements showed a significant and positive relationship with a high coefficient of determination for the estimation of the regression equations using BW and TC as the main explanatory variables. Breed-specific power regression equations as well as the 95% prediction intervals were calculated for each echocardiographic measurement as a function of BW and TC.Conclusions
In the future, the body size-corrected and breed-specific echocardiographic reference values calculated in the present study could be used to discriminate between normal and abnormal values in a given animal. 相似文献16.
Niwako Ogata Teppei Kanda Mizuki Kawahata Takayasu Ichikawa Yuki Matsumoto Waka Morimitsu Yukiko Nishino Takamasa Itoi Kayo Furumoto 《Veterinary anaesthesia and analgesia》2017,44(5):1091-1100
Objective
To determine the effects of brimonidine tartrate ophthalmic solution on sedation, heart rate (HR), respiratory frequency (fR), rectal temperature (RT) and noninvasive mean arterial pressure (MAP) in healthy cats.Study design
Randomized, blinded crossover study, with 1 week washout between treatments.Animals
Six healthy purpose-bred cats.Methods
Brimonidine tartrate ophthalmic solution 0.1% (one or two drops; 58.6 ± 3.3 μg per drop) or a control solution (artificial tear solution) was administered to six healthy cats. Behavioural observations and measurements of HR, fR, RT and MAP were recorded before and at 30, 60, 90, 120, 180, 240, 300 and 360 minutes after topical administration. Behavioural scores were analysed using Friedman’s test for repeated measures to evaluate the time effect in each treatment and treatment effect at each time point. Physiological variables (HR, fR, RT and MAP) were analysed using two-way analysis of variance for repeated measures to evaluate the time and treatment effects. The level of significance was set at p < 0.05.Results
Dose-dependent behavioural and physiological responses were noted. A dose of two drops of brimonidine resulted in sedation in the cats and decreased HR and MAP. Significant sedative effects occurred between 30 and 120 minutes and for physiological responses up to 360 minutes. The most frequent adverse reaction was vomiting, occurring within 40 minutes in all six cats administered two drops and five of the six cats administered one drop of brimonidine.Conclusions and clinical relevance
The results demonstrated that ocular administration of brimonidine 0.1% ophthalmic solution induced sedation in cats and some cardiovascular effects usually associated with α2-adrenoceptor agonists. Further studies should be performed to determine clinical applications for this agent in cats. 相似文献17.
Alessia Cenani Robert J. Brosnan Shara Madigan Heather K. Knych John E. Madigan 《Veterinary anaesthesia and analgesia》2017,44(1):86-97
Objective
Propranolol has been suggested for anxiolysis in horses, but its sedation efficacy and side effects, both when administered alone and in combination with α2-adrenoceptor agonists, remain undetermined. This study aimed to document the pharmacokinetics and pharmacodynamics of propranolol, romifidine and their combination.Study design
Randomized, crossover study.Animals
Six adult horses weighing 561 ± 48 kg.Methods
Propranolol (1 mg kg?1; treatment P), romifidine (0.1 mg kg?1; treatment R) or their combination (treatment PR) were administered intravenously with a minimum of 1 week between treatments. Alertness, behavioral responsiveness (visual and tactile) and physiologic variables were measured before and up to 960 minutes after drug administration. Blood was collected for blood gas and acid-base analyses and measurement of plasma drug concentrations. Data were analyzed using repeated-measures analysis of variance or Friedman with Holm–Sidak and Wilcoxon rank-sum tests (p < 0.05).Results
Systemic clearance significantly decreased and the area under the concentration-time curve significantly increased for both drugs in PR compared with P and R. Both PR and R decreased behavioral responsiveness and resulted in sedation for up to 240 and 480 minutes, respectively. Sedation was deeper in PR for the first 16 minutes. Heart rate significantly decreased in all treatments for at least 60 minutes, and PR significantly increased the incidence of severe bradycardia (<20 beats minute?1).Conclusions and clinical relevance
Although not associated with reduced behavioral responsiveness or sedation alone, propranolol augmented romifidine sedation, probably through alterations in romifidine pharmacokinetics, in horses administered PR. The occurrence of severe bradycardia warrants caution in the co-administration of these drugs at the doses studied. 相似文献18.
Objectives
To assess the influence of 2nd-degree AV blocks (AVB) on RR interval-based heart rate variability (HRV) variables; to investigate the effect of using PP interval time series and of artifact filtering on HRV analyses; to investigate the influence of electrocardiogram (ECG) recording length and time of recording; and to calculate day-to-day variability and reference intervals of HRV variables.Animals
Thirty healthy adult horses.Methods
RR and PP interval time series were extracted from 10-h Holter ECGs and an automated filter was applied to the RR time series (RRf). Time-domain HRV variables were calculated based on RR, PP, and RRf time series and their relation to the number of AVBs was assessed. Hourly 10- and 60-min segments were extracted to investigate the influence of segment length and recording time on HRV variables. Day-to-day variability and reference intervals of HRV variables were calculated.Results
Variables of short-term HRV were significantly influenced by the number of AVBs when based on RR, but not when based on PP- and RRf time series. PP- and RRf-based HRV variables were in good agreement. The majority of HRV variables were influenced by recording time and ECG segment length. Day-to-day variability of HRV variables was low when based on 10-h ECG recordings but moderate to high when based on 60-min and 10-min recordings.Conclusions
Second-degree AVBs significantly influence conventional RR-based, but not PP- and RRf-based time-domain HRV variables. However, PP and RRf analyses have limitations and recording length and time of recording must be considered. 相似文献19.
Claudio C. Natalini Carolina L. Krahn Priscila B.S. Serpa Joanna E. Griffith Ricardo Miyasaka de Almeida 《Veterinary anaesthesia and analgesia》2017,44(2):219-227
Objective
To investigate the efficacy of a new intravenous (IV) nanoemulsified isoflurane formulation for maintenance of general anesthesia in dogs.Study design
Prospective, crossover, experimental study.Animals
Seven healthy, mature, mixed-breed dogs, three male and four female, weighing 11.5 ± 1.5 kg.Methods
Anesthesia was induced with propofol for instrumentation. Measurements were obtained before administration of either inhaled isoflurane (Iso-I) or IV 15% isoflurane-loaded lipid nanoemulsion (Iso-nano). The minimum alveolar concentration (MAC) of isoflurane was determined using the ‘up-and-down’ technique. A tail clamp was applied every 15 minutes for a total time of 90 minutes and isoflurane administration was adjusted according to the response. Data were recorded at 30, 60 and 90 minutes for end-tidal isoflurane concentration (Fe´Iso), end-tidal carbon dioxide partial pressure (Pe′CO2), inspired isoflurane concentration (FIIso), arterial hemoglobin oxygen saturation (SaO2), peripheral hemoglobin oxygen saturation (SpO2), respiratory rate (fR), heart rate (HR), arterial blood pH, PaCO2, PaO2, base excess (BE), bicarbonate (HCO3?), systemic arterial pressure (sAP), and biochemical variables of blood urea nitrogen, alanine aminotransferase, creatine kinase and creatinine.Results
No significant differences between treatments were detected for HR, fR, SaO2 or any biochemical variables (p > 0.05). In the Iso-nano treatment, sAP was significantly decreased throughout the study. Significant decreases in pH, Pe′CO2, BE and HCO3? were measured in the Iso-nano treatment. Isoflurane MAC was significantly lower in the Iso-nano than the Iso-I treatment. The dose of isoflurane (g hour?1) required to maintain general anesthesia did not differ significantly between treatments.Conclusions and clinical relevance
Administration of 15% isoflurane-loaded lipid nanoemulsion IV was effective in maintaining general anesthesia in dogs but did not reduce the amount of isoflurane necessary to maintain general anesthesia. Significant hypotension and nonrespiratory acidosis occurred with the injectable form. 相似文献20.
Dienifer V. Sutil Cláudio R.S. Mattoso Julieta Volpato Nádia C. Weinert Ádson Costa Rozyanne R. Antunes Thiago R. Muller Suzane L. Beier Ronise Tochetto Felipe Comassetto Mere E. Saito 《Veterinary anaesthesia and analgesia》2017,44(4):746-754