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1.
Nicola Wiedemann Nicolai Hildebrandt Gabriel Wurtinger Estelle Henrich Esther Hassdenteufel Matthias Schneider 《Journal of Veterinary Cardiology》2017,19(3):247-255
Background
Increased cardiac troponin I (cTnI) concentration has been reported in dogs with atrioventricular (AV) block before and shortly following pacemaker implantation. The role of AV dyssynchrony, age, or concurrent cardiac disease on cTnI concentration remains unknown.Objectives
To investigate change in cTnI concentration following dual-chamber pacemaker implantation on short- and long-term follow-up and to compare cTnI values to a case-matched control group.Animals
Thirty-eight client-owned dogs with permanent AV block and 38 matched control dogs.Methods
Retrospective review of medical records. Pacemaker group consisted of dogs with AV block and dual-chamber pacing. Control group matched the study population in age and cardiac disease. cTnI was compared between pacemaker and control group on short- and long-term follow-up. Different lead types and influence of arrhythmia on cTnI were tested.Results
cTnI was high at presentation (median 0.66 ng/ml; range 0.03–18.6) and showed a significant reduction over time after pacemaker implantation (p < 0.0001). Median cTnI values were significantly different between pacemaker and control group on short-term (p = 0.0004; 0.11 ng/ml, range 0.03–1.36 versus 0.06 ng/ml, range 0.03–0.46), but not on long-term follow-up (p = 0.0547; 0.14 ng/ml, range 0.03–0.73 versus 0.07 ng/ml, range 0.03–0.46). Lead type and severity of arrhythmia did not show a significant correlation to cTnI concentration.Conclusions
On long-term follow-up, cTnI remained mildly elevated in some of the pacemaker dogs but was not significantly different to the matched control group. 相似文献2.
R.D. Baumwart A.S. Hanzlicek S.D. Lyon P.M. Lee 《Journal of Veterinary Cardiology》2017,19(5):416-420
Objective
To determine if concentrations of plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) are increased in dogs with cardiac tamponade and if there is a significant increase in plasma NT-proBNP after pericardiocentesis.Animals
Ten client-owned dogs with spontaneous cardiac tamponade.Methods
Prospective clinical study. Cardiac tamponade was suspected from physical examination and confirmed with echocardiography. Blood was collected and plasma NT-proBNP concentrations were measured before and 30–60 min following pericardiocentesis and resolution of cardiac tamponade. Within-subject changes in plasma NT-proBNP were compared by the Wilcoxon signed-rank test.Results
The plasma NT-proBNP concentrations measured within the reference interval in seven of 10 dogs before pericardiocentesis and in six of 10 dogs following pericardiocentesis. Following pericardiocentesis, there was a statistically significant increase in median NT-proBNP concentration (733 pmol/L, range 250–3,297) compared with the values measured before (643 pmol/L, range 250–3,210, P = 0.004). The NT-proBNP concentration increased in 90% of the dogs following pericardiocentesis.Conclusions
An upper reference limit of 900 pmol/L for plasma NT-proBNP is insensitive for the diagnosis of pericardial effusion and cardiac tamponade in dogs. Plasma NT-proBNP concentration commonly increases following pericardiocentesis, perhaps related to improved ventricular filling and stretch. 相似文献3.
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4.
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
Objective
To evaluate the onset and duration of hematological changes and the use of Doppler ultrasound (spleen) in dogs sedated with acepromazine or xylazine.Study design
Clinical study.Animals
A total of 24 mixed breed dogs aged 1–4 years and weighing 15–25 kg.Methods
Dogs were randomly distributed into two groups: acepromazine group (AG) which were administered acepromazine (0.05 mg kg?1) intramuscularly and xylazine group (XG) administered xylazine (0.5 mg kg?1) intramuscularly. Sonographic evaluations (morphologic and hemodynamic splenic vascularization) and hematologic tests were performed before drug administration (baseline) and 5, 15, 30, 60, 120, 240, 360, 480 and 720 minutes after drug administration.Results
A significant reduction occurred in erythrogram variables in AG at 15–720 minutes corresponding with a significant enlargement of the spleen. In XG, a significant reduction was observed in the erythrogram variables at 30–60 minutes without a significant enlargement of the spleen. Hilar diameter did not change over time in either group. Flow alterations were found only in the splenic artery in AG, with a decreased final diastolic velocity observed at 60–120 minutes.Conclusions
Administration of acepromazine resulted in decreased red blood cell count, hemoglobin, packed cell volume and an increased diameter of the spleen. Xylazine administration resulted in similar hematologic changes but of smaller magnitude and duration and without splenic changes. The absence of significant changes in the Doppler flow parameters of the splenic artery and vein and the hilar diameter suggests that the splenomegaly that was observed in AG was not due to splenic vasodilation. No splenic sequestration occurred after xylazine administration.Clinical relevance
The results indicate that acepromazine decreases the erythrocyte concentrations by splenic erythrocyte sequestration and concomitant splenomegaly. Xylazine can cause slight hematologic changes, but without splenic changes. 相似文献5.
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6.
Ryan S. Bailey Linda S. Barter Bruno H. Pypendop 《Veterinary anaesthesia and analgesia》2017,44(4):876-882
Objective
To characterize the pharmacokinetics of dexmedetomidine when administered as a short intravenous (IV) infusion to isoflurane-anesthetized rabbits.Study design
Experimental study.Animals
A total of six healthy adult female New Zealand White rabbits.Methods
Rabbits were anesthetized with isoflurane in oxygen. Following determination of isoflurane minimum alveolar concentration (MAC), the anesthetic dose was reduced to 0.7 × MAC, and dexmedetomidine hydrochloride (20 μg kg?1) was infused IV over 5 minutes. Arterial blood samples were obtained immediately before and at 1, 2, 5, 6, 7, 10, 15, 30, 60, 90, 120, 240 and 360 minutes following termination of the infusion. Samples were transferred into tubes containing ethylenediaminetetraacetic acid and centrifuged immediately. The plasma was harvested and stored at –80 °C until analyzed. Concentrations of dexmedetomidine in plasma were determined by liquid chromatography mass spectrometry. Compartment models were fitted to the time and concentration data using nonlinear regression.Results
A three-compartment model best fit the data set. Median volume of distribution at steady state and terminal half-life were 3169 mL kg?1 (range, 2182–3859 mL kg?1) and 80 minutes (range, 72–88 minutes), respectively.Conclusions and clinical relevance
The pharmacokinetics of dexmedetomidine in isoflurane-anesthetized, healthy, New Zealand White rabbits were characterized in this study. Data from this study can be used to determine dosing regimens for dexmedetomidine in isoflurane-anesthetized rabbits. 相似文献7.
Josiane Lauper Vincent Marolf Olivier Levionnois Esther Schelling Mireille Meylan Claudia Spadavecchia 《Veterinary anaesthesia and analgesia》2017,44(2):281-286
Objective
To investigate whether an intravenous (IV) lidocaine bolus in calves premedicated with xylazine-butorphanol reduces the amount of ketamine required to allow endotracheal intubation.Study design
Randomized, prospective clinical study.Animals
In total, 41 calves scheduled for elective umbilical surgery.Methods
Calves were randomly assigned to one of two groups (L: lidocaine or S: saline). The calves were administered xylazine (0.07 mg kg?1) and butorphanol (0.1 mg kg?1) intramuscularly and 10 minutes later lidocaine (2 mg kg?1; group L) or saline (group S) IV over 1 minute. After 2 minutes, ketamine (2.5 mg kg?1) was injected IV. If the depth of anaesthesia was insufficient for intubation, additional ketamine (1 mg kg?1) was administered every minute until intubation was successful. The amount of ketamine required for intubation, respiratory rate, pulse rate, arterial pressures, the depth of sedation and conditions of endotracheal intubation after induction of anaesthesia were compared between the two groups.Results
The calves in group L were sedated more deeply than those in group S; however, neither the median (range) amount of ketamine required for intubation, 3.5 (2.5–4.5) mg kg?1 and 3.5 (2.5–3.5) mg kg?1, respectively, nor the induction quality differed significantly between the groups.Conclusion and clinical relevance
A bolus of lidocaine (2 mg kg?1) administered 10 minutes after xylazine-butorphanol in calves deepened the degree of sedation but did not decrease the requirement of ketamine for endotracheal intubation. No adverse effects were recorded in the physiological variables measured. 相似文献8.
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9.
Etiane M.H. Saccol Érika P. Londero Caroline A. Bressan Joseânia Salbego Luciane T. Gressler Lenise V.F. Silva Rosa H.V. Mourão Ricardo B. Oliveira Susana F. Llesuy Bernardo Baldisserotto Maria A. Pavanato 《Veterinary anaesthesia and analgesia》2017,44(3):555-566
Objective
To investigate the effects of rapid anesthesia and long-term sedation with the essential oils (EOs) of Myrcia sylvatica (EOMS) and Curcuma longa (EOCL) on biochemical and oxidative parameters in matrinxã.Study design
Prospective, randomized, laboratory experiment.Animals
A total of 72 matrinxã (Brycon amazonicus) adults weighing 404.8 ± 27.9 g were divided into eight groups of nine fish.Methods
Biochemical and oxidative effects were investigated in plasma and tissues of matrinxã subjected to rapid anesthesia (5 minutes) or long-term sedation (360 minutes, simulating the practice of transport) with EOMS (200 μL L?1 and 10 μL L?1, respectively) and EOCL (500 μL L?1 and 40 μL L?1, respectively).Results
Transport simulation without sedation or anesthesia increased lipid peroxidation levels in the gills and kidney of fish in the control group. Anesthesia and sedation with EOs decreased cortisol concentrations and increased lactate concentrations compared with controls. Lipid peroxidation was lower in the brain, gills, liver and kidney of sedated and anesthetized fish, than in the control group. Anesthesia with EOs increased the activity of superoxide dismutase and glutathione-S-transferase in the brain, and catalase in the liver and gills, compared with controls. Long-term sedation with EOs increased superoxide dismutase, glutathione peroxidase and glutathione reductase activities in the brain, catalase in the liver, glutathione peroxidase and glutathione reductase in the gills and superoxide dismutase in the kidney. In general, nonprotein thiols content and total reactive antioxidant potential of tissues were higher after anesthesia and sedation with EOs compared with the control group.Conclusions and clinical relevance
The concentrations of EOMS and EOCL used were effective at preventing a stress response and excess of reactive oxygen species formation. For these reasons, these substances may be recommended for use in the transportation of fish to improve survival and animal welfare. 相似文献10.
Sarah E. Bigby Jennifer E. Carter Sébastien Bauquier Thierry Beths 《Veterinary anaesthesia and analgesia》2017,44(4):905-909
Objective
The evaluation of alfaxalone as a premedication agent and intravenous anaesthetic in pigs.Study design
Prospective, clinical trial.Animals
Nine healthy, 6–8-week-old female Landrace pigs weighing 22.2 ± 1.0 kg, undergoing epidural catheter placement.Methods
All pigs were premedicated with 4 mg kg?1 alfaxalone, 40 μg kg?1 medetomidine and 0.4 mg kg?1 butorphanol administered in the cervical musculature. Sedation was subjectively scored by the same observer from 1 (no sedation) to 10 (profound sedation) prior to induction of anaesthesia with alfaxalone intravenously to effect. All pigs were maintained on alfaxalone infusions with the rate of administration adjusted to maintain appropriate anaesthetic depth. Quality of induction was scored from 1 (poor) to 3 (smooth) and basic cardiorespiratory variables were recorded every 5 minutes during anaesthesia. Results are reported as mean ± standard deviation or median (range) as appropriate.Results
Sedation scores were 9 (7–10). Inductions were smooth in all pigs and cardiovascular variables remained within normal limits for the duration of anaesthesia. The induction dose of alfaxalone was 0.9 (0.0–2.3) mg kg?1. Three pigs did not require additional alfaxalone after premedication to facilitate intubation.Conclusions and clinical relevance
Intramuscular alfaxalone in combination with medetomidine and butorphanol produced moderate to deep sedation in pigs. Alfaxalone produced satisfactory induction and maintenance of anaesthesia with minimal cardiovascular side effects. Appropriate monitoring of pigs premedicated with this protocol is required as some pigs may become anaesthetized after intramuscular administration of this combination of drugs. 相似文献11.
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12.
13.
Kaylee S. Bohaychuk-Preuss M. Valentina Carrozzo Tanya Duke-Novakovski 《Veterinary anaesthesia and analgesia》2017,44(3):483-491
Objective
To record the cardiopulmonary effects of pleural CO2 positive pressure insufflation in anesthetized horses.Study design
Prospective study.Animals
Seven horses (mean ± standard deviation, 530.9 ± 68.1 kg) undergoing terminal surgery.Methods
Horses were sedated with xylazine. Anesthesia was induced with ketamine–propofol and maintained with isoflurane, positive pressure ventilation, detomidine infusion, and butorphanol with the horses in dorsal recumbency. Baseline measurements were cardiac output, heart rate, pulmonary and systemic arterial and right atrial blood pressures, body temperature, expired and inspired gas concentrations, and arterial and mixed venous blood gases, electrolytes, glucose, and lactate concentrations. An 18 gauge 6.6 cm needle was inserted into the right pleural cavity midway between the sternum and dorsal midline in the sixth or seventh intercostal space for pleural pressure (PP) measurement. A 14 gauge 18 cm needle placed 5 cm below the previous needle allowed CO2 insufflation into the pleural cavity. All measurements were repeated after: needle insertion, at 2, 5, and 8 mmHg PPs, and after pleural gas removal (GR). Data were compared with baseline using one-way analysis of variance with repeated measures. p < 0.05 was considered significant.Results
Actual PPs were within 1.1 mmHg of the targeted PP. Pulmonary systolic and mean arterial pressures, alveolar dead space to tidal volume ratio, and isoflurane requirements increased at 8 mmHg PP and GR. Cardiac index decreased at 5 mmHg PP. Stroke index decreased at 2 mmHg PP to GR. PaO2 decreased at 5 mmHg PP to GR. PaCO2 increased at 8 mmHg PP and GR. Oxygen delivery decreased at 5 and 8 mmHg PP. Intrapulmonary shunt fraction and lactate concentration increased with GR.Conclusions and clinical relevance:
Severe adverse cardiopulmonary effects arise from CO2 positive pressure insufflation into the right hemithorax in dorsally recumbent isoflurane-anesthetized horses. PP should be ≤2 mmHg. 相似文献14.
Flavia Restitutti M. Johanna Kaartinen Marja R. Raekallio Otto Wejberg Emmi Mikkola Jerome R.E. del Castillo Mika Scheinin Outi M. Vainio 《Veterinary anaesthesia and analgesia》2017,44(3):417-426
Objective
We investigated the plasma concentrations and cardiovascular effects of intramuscularly (IM) administered medetomidine, administered alone or with three different doses of MK-467.Study design
Prospective, randomized, open, crossover trial.Animals
Eight purpose-bred healthy Beagle dogs.Methods
Each dog was administered four treatments: medetomidine 20 μg kg–1 IM alone or mixed in the same syringe with MK-467 (200 μg kg–1, 400 μg kg–1 or 600 μg kg–1). Instrumentation was performed under standardized anaesthesia. The dogs were allowed to recover before measurement of baseline values. Composite sedation scores, cardiovascular variables, i.e., heart rate (HR), cardiac output (CO), mean arterial and central venous blood pressures (MAP and CVP) and arterial blood gases were recorded at baseline and for 60 minutes after treatment. Drug concentrations in venous plasma were analysed. Generalized linear mixed models for repeated measures with post hoc Bonferroni correction were used with statistical significance level set at α = 0.05.Results
All treatments initially demonstrated the effects of medetomidine: HR and CO decreased and CVP increased. MAP transiently increased and then significantly decreased from baseline with the two highest MK-467 doses. The cardiovascular effects of medetomidine disappeared more rapidly with MK-467 than with medetomidine alone. With medetomidine alone, sedation scores remained high until the end of the 60 minute follow-up. Maximum concentrations of medetomidine were more rapidly achieved and were higher with MK-467.Conclusions and clinical relevance
Initial haemodynamic effects of medetomidine were not prevented by MK-467, but these effects were attenuated and their duration shortened by MK-467, independently of dose. Absorption of medetomidine was accelerated by MK-467, when administered concomitantly IM, resulting in faster sedation; addition of MK-467 shortened the sedative effect of medetomidine. 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.
Stephanie Stauffer Beckie Cordner Jonathon Dixon Thomas Witte 《Veterinary anaesthesia and analgesia》2017,44(4):951-958
Objective
The aim of this preliminary proof-of-concept study was to evaluate and compare the success and complication rate of infiltration of the maxillary nerve of cadaver heads using previously described surface landmarks, standard ultrasound and a novel needle guidance positioning ultrasound system (SonixGPS).Study design
Prospective, anatomical, method-comparison study.Animals
Thirty-eight equine cadaver heads.Methods
Twenty-six veterinary students performed the three methods consecutively on cadaver heads using an 18 gauge, 8.9 cm spinal needle and 0.5 mL iodinated contrast medium. Computed tomography was used to quantify success (deposition of contrast in contact with the maxillary nerve) and complication rate (contrast identified within surrounding vasculature or periorbital structures) associated with each method.Results
Perineural injection of the maxillary nerve was attempted 76 times, with an overall success rate of 65.8% (50/76) and complication rate of 53.9% (41/76). Success rates were 50% (13/26) with surface landmark, 65.4% (17/26) with standard ultrasound guidance and 83.3% (20/24) with SonixGPS guidance approaches (Fisher's exact test, p = 0.046). No significant difference in complication rate was found between the three methods.Conclusions
Ultrasound-guided maxillary nerve blocks were significantly more successful than surface landmark approaches when performed by inexperienced operators, and the highest success rate was achieved with guidance positioning system (GPS) needle guidance.Clinical relevance
Local anaesthesia of the equine maxillary nerve in the fossa pterygopalatina is frequently used for diagnostic and surgical procedures in the standing sedated horse. Due to vague superficial landmarks with various approaches and the need for experience via ultrasound guidance, this block remains challenging. GPS guidance may improve reliability of maxillary and other nerve blocks, and allow a smaller volume of local anaesthetic solution to be used, thereby improving specificity and reducing the potential for side effects. 相似文献17.
Robert J. Brosnan Fabíola B. Fukushima Trung L. Pham 《Veterinary anaesthesia and analgesia》2017,44(3):577-588
Objective
N-butane and n-pentane can both produce general anesthesia. Both compounds potentiate γ-aminobutyric acid type A (GABAA) receptor function, but only butane inhibits N-methyl-d-aspartate (NMDA) receptors. It was hypothesized that butane and pentane would exhibit anesthetic synergy due to their different actions on ligand-gated ion channels.Study design
Prospective experimental study.Animals
A total of four Xenopus laevis frogs and 43 Sprague–Dawley rats.Methods
Alkane concentrations for all studies were determined via gas chromatography. Using a Xenopus oocyte expression model, standard two-electrode voltage clamp techniques were used to measure NMDA and GABAA receptor responses in vitro as a function of butane and pentane concentrations relevant to anesthesia. The minimum alveolar concentrations (MAC) of butane and pentane were measured separately in rats, and then pentane MAC was measured during coadministration of 0.25, 0.50 or 0.75 times MAC of butane. An isobole with 95% confidence intervals was constructed using regression analysis. A sum of butane and pentane that was statistically less than the lower-end confidence bound isobole indicated a synergistic interaction.Results
Both butane and pentane dose-dependently potentiated GABAA receptor currents over the study concentration range. Butane dose-dependently inhibited NMDA receptor currents, but pentane did not modulate NMDA receptors. Butane and pentane MAC in rats was 39.4 ± 0.7 and 13.7 ± 0.4 %, respectively. A small but significant (p < 0.03) synergistic anesthetic effect with pentane was observed during administration of either 0.50 or 0.75 × MAC butane.Conclusions
Butane and pentane show synergistic anesthetic effects in vivo consistent with their different in vitro receptor effects.Clinical relevance
Findings support the relevance of NMDA receptors in mediating anesthetic actions for some, but not all, inhaled agents. 相似文献18.
D.A. Frese J.D. Thomason C. Reinhardt S. Bartle D. Rethorst G.H. Loneragan D. Thomson 《Journal of Veterinary Cardiology》2017,19(2):153-159
Introduction
Atrial premature complexes have been reported to be the most common arrhythmia in cattle and is suspected to be secondary to systemic disease, especially gastrointestinal disease. In order to properly identify pathologic arrhythmia in cattle, the normal rhythm and arrhythmia prevalence should be defined. The objective of this study was to determine the normal heart rate, rhythm, number of ventricular premature complexes (VPCs), and atrial premature complexes (APCs) in unrestrained Angus steers.Animals
Twenty-seven client owned steers with unremarkable physical examinations and serum biochemical analyses were used.Materials and methods
Twenty-four hour Holter monitors, attached by a custom-made harness, were retrospectively evaluated. Three lead electrocardiographic registrations of good quality and normal sinus rhythm were obtained from all steers in the study.Results
The mean heart rate was 66.8 bpm ± 16.4 bpm. Ventricular premature complexes were rare (noted in 14.8% of steers), and APCs were common (noted in 85% of the steers). Simple second degree AV block was observed in 18.5% of the steers.Conclusion
In summary, healthy steers have rare single VPCs, although it is possible for an individual animal to have apparent more frequent VPCs. Mean heart rate varies with a diurnal pattern similar to other species. Atrial premature complexes are the most prevalent abnormality observed in feedlot steers. 相似文献19.
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20.
M.W. Nolan M.M. Arkans D. LaVine T. DeFrancesco J.A. Myers E.H. Griffith L.P. Posner B.W. Keene S.P. Tou T.L. Gieger 《Journal of Veterinary Cardiology》2017,19(2):132-143