Comparison of the sedative effects of three nalbuphine doses, alone or combined with acepromazine, in dogs.

OBJECTIVE: To compare sedative, cardiopulmonary, and adverse effects of 3 nalbuphine doses, administered alone or in combination with acepromazine, in dogs. ANIMALS: 6 healthy dogs. PROCEDURES: Dogs were administered nalbuphine (1.0, 1.5, or 2.0 mg/kg, intravenously [IV]) combined with physiologic saline solution (1 mL, IV; treatments SN1.0, SN1.5, and SN2.0, respectively) or acepromazine (0.05 mg/kg, IV; treatments AN1.0, AN1.5, and AN2.0, respectively) in random order, with a 1-week washout interval between treatments. Sedation scores, heart rate, mean arterial pressure, respiratory rate, and rectal temperature were recorded before and 20 minutes after administration of saline solution or acepromazine (T0), and nalbuphine was administered at T0. Measurements were repeated 15, 30, 60, 90, and 120 minutes after nalbuphine administration. RESULTS: Treatments SN and AN resulted in at least 120 minutes of mild sedation and 60 minutes of moderate sedation, respectively. Sedation scores were greater for treatments AN1.0, AN1.5, and AN2.0 at various times, compared with scores for treatments SN1.0, SN1.5, and SN2.0, respectively. Administration of nalbuphine alone resulted in salivation and panting in some dogs. CLINICAL RELEVANCE: All nalbuphine doses promoted mild sedation when administered alone, and moderate sedation when combined with acepromazine. Greater doses of nalbuphine did not increase sedation scores. All treatments resulted in minimal changes in heart rate, respiratory rate, rectal temperature, and mean arterial pressure. Nalbuphine alone resulted in few adverse effects.

Description and validation of a new descriptive and multiparametric numeric rating scale to assess sedation in cats.

The objective of this study was to design and assess the validity and reliability of a new feline multiparametric sedation scale (FMSS). A total of 89 household cats were recruited, enabling a total of 534 sedation assessments. Every assessment was performed by 3 blinded observers with varying expertise levels (Level 1: Student; Level 2: RVT; Level 3: ACVAA diplomate or senior resident). For comparison purposes, a visual analogue scale (VAS) and a Simple Qualitative Scale (SQS) were also used concurrently, with the VAS considered the gold standard. The new scale had excellent inter-observer agreement among experience groups with weighted Kappa scores of 0.84 (Levels 1 versus 2), 0.82 (Levels 2 versus 3), and 0.84 (Levels 1 versus 3), with P < 0.0001 for all comparisons. There was a high degree of association between FMSS and VAS (r = 0.90, P < 0.0001) and between FMSS and SQS (r = 0.89, P < 0.0001). Final FMSS numerical values were paired with levels of sedation with None = 0 (0 to 5), Mild = 4 (1 to 7), Moderate = 6 (2 to 10), and Profound = 12 (7 to 12); furthermore, differences were detected between pre- and post-sedation evaluations (P = 0.001). This scale demonstrated internal consistency and sensitivity even when evaluating drugs or doses with minimal sedative effects and there was very strong interrater reliability, independent of experience level. Based on this clinical study, we concluded that the use of this sedation scale is appropriate when objective numerical sedation quantification is required, in either a clinical or research setting.

Description et validation d'une nouvelle échelle d'évaluation numérique descriptive et multiparamétrique pour évaluer la sédation chez le chat. L'objectif de cette étude était de concevoir et d'évaluer la validité et la fiabilité d'une nouvelle échelle de sédation multiparamétrique féline (FMSS). Un total de 89 chats domestiques a été recruté, permettant un total de 534 évaluations de sédation. Chaque évaluation a été effectuée par trois observateurs en aveugle avec différents niveaux d'expertise (Niveau 1 : étudiant; Niveau 2 : RVT; Niveau 3 : diplomate de l'ACVAA ou résident senior). À des fins de comparaison, une échelle visuelle analogique (VAS) et une échelle qualitative simple (SQS) ont également été utilisées simultanément, VAS étant considérée comme l'étalon. La nouvelle échelle présentait un excellent accord inter-observateurs parmi les groupes d'expérience avec des scores Kappa pondérés de 0,84 (niveaux 1 versus 2), 0,82 (niveaux 2 versus 3) et 0,84 (niveaux 1 versus 3), avec P < 0,0001 pour toutes les comparaisons. Il y avait un degré élevé d'association entre FMSS et VAS (r = 0,90, P < 0,0001) et entre FMSS et SQS (r = 0,89, P < 0,0001). Les valeurs numériques FMSS finales ont été appariées avec les niveaux de sédation avec Aucun = 0 (0 à 5), Léger = 4 (1 à 7), Modéré = 6 (2 à 10) et Profond = 12 (7 à 12); en outre, des différences ont été détectées entre les évaluations pré- et post-sédation (P = 0,001). Cette échelle a démontré une cohérence interne et une sensibilité même lors de l'évaluation de médicaments ou de doses avec des effets sédatifs minimes et il y avait une très forte fiabilité inter-évaluateur, indépendamment du niveau d'expérience. Sur la base de cette étude clinique, nous avons conclu que l'utilisation de cette échelle de sédation est appropriée lorsqu'une quantification numérique objective de la sédation est requise, dans un cadre clinique ou de recherche.(Traduit par Dr Serge Messier).

Avian Sedation.

The use of procedural sedation in birds has become a routine practice in veterinary medicine during the past 10 years, with a corresponding increase in avian sedation research. Sedation is most often used in a clinical setting for birds to facilitate examination and/or diagnostic sample collection, splint application, grooming, and minor surgical procedures. Sedation provides several benefits over manual restraint or general anesthesia when performing clinical procedures. This review provides an overview of current studies on avian sedation and discusses common indications, protocols, and adverse effects of sedation in avian patients.

STANDING SEDATION WITH XYLAZINE AND REVERSAL WITH YOHIMBINE IN JUVENILE ASIAN ELEPHANTS (ELEPHAS MAXIMUS).

Evaluation and improvement of immobilization methods are important for wildlife welfare and biodiversity conservation. The sedative and physiological effects of xylazine (50-110 mg per elephant; 0.09-0.15 mg/kg IM) were evaluated in 15 juvenile Asian elephants (Elephas maximus) in Sri Lanka. The time from xylazine injection until first sign of sedation, handling, and reversal with yohimbine (0.009-0.03 mg/kg IV) were recorded. Behavioral signs, level of sedation (no effect, light, moderate, or deep) and response to handling were assessed. Rectal temperature, pulse, and respiratory rates were recorded and arterial blood samples were analyzed 30 and 45 min after xylazine injection. The first sign of sedation occurred within 5-18 min. Standing sedation was induced in all elephants, but the level of sedation varied differently over time for each elephant. Twelve elephants remained standing throughout the sedation period, while 3 elephants became laterally recumbent. Sedative effects included lowered head and trunk, droopy ears, snoring, and penis protrusion. Pulse rate, respiratory rate, and rectal temperature ranged between 30-45 beats/min, 4-12 breaths/min, and 35.6-37.2°C, respectively, at 30 min after xylazine injection, and there were no changes over time. Pulmonary function and acid-base balance were adequate (range partial pressures of arterial oxygen 73-123 mmHg and carbon dioxide 33-52 mmHg, arterial hemoglobin oxygen saturation 96-99%, pH 7.34-7.54, lactate 0.9-2.5 mmol/L). Yohimbine was administered 46-110 min after the injection of xylazine, and the first sign of recovery occurred within 1-4 min. Resedation after reversal with yohimbine was observed in two elephants. In conclusion, xylazine at the doses used induced light to deep sedation with stable physiology and most elephants remained standing.

EVALUATING THE USE OF A BUTORPHANOL-AZAPERONE-MEDETOMIDINE FIXED-DOSE COMBINATION FOR STANDING SEDATION IN AFRICAN ELEPHANTS (LOXODONTA AFRICANA).

This study investigated the use of a fixed-dose combination of 30 mg/ml butorphanol, 12 mg/ml azaperone, and 12 mg/ml medetomidine for the standing sedation of captive African elephants (Loxodonta africana). In total, seven females (mean age 19.6 yr; range 6-31 yr) and six males (mean age 33.5 yr; range 9-35 yr) were sedated. The estimated dose was 0.0005 ± 0.0001 ml/kg and 0.006 ± 0.001 ml/cm shoulder height, which resulted in a dose of 0.016 ± 0.002 mg/kg or 0.19 ± 0.04 mg/cm shoulder height butorphanol, 0.006 ± 0.0008 mg/ kg or 0.076 ± 0.015 mg/cm shoulder height azaperone, and 0.006 ± 0.0008 mg/kg or 0.076 ± 0.015 mg/cm medetomidine. First signs of sedation were observed within 3-10 min (mean 6 ± 2 min) after darting, and monitoring of the animals started on average at 24 ± 9 min after darting. No bradycardia was observed in any of the elephants (mean heart rate 40.0 ± 6.55 beats/min), although all the animals were mildly hypotensive (mean blood pressure 118.5/86 [94.5]). Rectal temperatures fell within acceptable ranges, and respiratory parameters were stable in all the animals throughout sedation and fell within the standard ranges reported for conscious, standing elephants. Only one elephant had clinically significant hypoxemia characterized by a partial pressure of oxygen (PaO2) < 60 mm Hg. This elephant was also hypercapnic (PaCO2 > 50 mm Hg), although pH and peripheral capillary oxygen saturation fell within acceptable ranges. None of the elephants reacted to moderately painful stimuli while sedated. The combination was reversed with intramuscular injections of naltrexone (1 mg for every 1 mg butorphanol) and atipamezole (5 mg for every 1 mg medetomidine). Recovery was smooth and calm in all the animals. Time from injection of the reversals until the first signs of recovery was 4.6 ± 2.01 min (range 1-8 min).

Effects of head position on internal and external carotid pressures in standing sedated horses.

The effects of head position on internal carotid artery (ICA) and external carotid artery (ECA) pressures in standing sedated horses were evaluated in this study. The common carotid artery (CCA) was catheterized in 6 horses using an ultrasound-guided technique to facilitate placement of a pressure transducer within the ICA and ECA at the level of the guttural pouch. Transducer position was confirmed by endoscopic visualization. Mean arterial pressure (MAP) was measured with horses in both a head-up and head-down position. The dorsal metatarsal artery was catheterized as a control. Maintaining a head-up position decreased MAP in both the ICA (median: 75.21 mmHg) and ECA (median: 79.43 mmHg), relative to the head-down position (ICA median: 104.65 mmHg; ECA median: 102.26 mmHg). Mean arterial pressure in the dorsal metatarsal artery was not affected by head position. The head-up position resulted in lower arterial pressures in both the ICA and ECA (P = 0.03) compared with the head-down position in standing sedated horses.

Cette étude a évalué les effets de la position de la tête sur la pression artérielle au niveau de l'artère carotide interne (ICA) et de l'artère carotide externe (ECA) chez des chevaux sous sedation debout. L'artère carotide commune (CCA) a été cathétérisée chez six chevaux en utilisant une technique échoguidée pour faciliter le placement d'un transducteur de pression dans l'ICA et l'ECA au niveau de la poche gutturale. La position du transducteur a été confirmée par endoscopie. La pression artérielle moyenne (MAP) a été mesurée chez les chevaux avec la tête en position haute et en position basse. L'artère métatarsienne dorsale a été cathétérisée et a servi comme témoin. Les MAP enregistrées au niveau de l'ICA (médiane: 75,21 mmHg) et de l'ECA (médiane: 79,43 mmHg) lorsque la tête est en position élevée sont plus faibles que celles enregistrées lorsque la tête est en position basse (médiane ICA: 104,65 mmHg; médiane ECA: 102,26 mmHg). La MAP de l'artère métatarsienne dorsale n'a pas été affectée par la position de la tête. En conclusion, chez les chevaux sédatés et debout, la position élevée de la tête produit des pressions artérielles plus faibles au niveau de ICA et ECA (P = 0,03) que celles obtenues lorsque la tête est en position basse.(Traduit par les auteurs).

The effects of two intramuscular sedation protocols on echocardiographic variables in cats following sedation and blood donation.

OBJECTIVE: To compare effects of 2 IM sedation protocols, alfaxalone-butorphanol (AB) versus dexmedetomidine-butorphanol (DB), on echocardiographic (ECHO) variables in cats following sedation and blood donation. DESIGN: Experimental randomized, blinded crossover study. SETTING: University teaching hospital. ANIMALS: Eleven client-owned healthy cats. INTERVENTIONS: Cats received a baseline ECHO without sedation prior to their first donation. Cats were sedated intramuscularly with AB (alfaxalone, 2 mg/kg, and butorphanol, 0.2 mg/kg) for 1 donation and DB (dexmedetomidine, 10 µg/kg, and butorphanol 0.2, mg/kg) for another, with a minimum 6 weeks between donations. A post-sedation, post-donation ECHO was performed after each blood donation. MEASUREMENTS AND MAIN RESULTS: Eight cats completed the study. Compared to baseline, DB combined with blood donation decreased heart rate (-84/min; P < 0.0001), fractional shortening (-16.5%; P < 0.0001), ejection fraction (-21.0%; P = 0.0002), and cardiac output (-292 mL/min, P = 0.0001); AB combined with blood donation increased heart rate (+45/min; P = 0.0003) and decreased left ventricular end diastolic volume (-1.57 mL; P < 0.0001). Compared to AB, DB decreased heart rate (-129/min; P < 0.0001) and fractional shortening (-21.6%; P < 0.0001) and increased left ventricular end-systolic (+1.14 mL; P = 0.0004) and diastolic volumes (+1.93 mL; P < 0.0002). Cats administered DB had a significant increase in regurgitant flow across mitral, aortic, and pulmonic valves following blood donation (P < 0.05). One cat administered DB developed spontaneous echo contrast in the left ventricle following donation. CONCLUSIONS AND CLINICAL RELEVANCE: Compared to AB, DB had more pronounced effects on ECHO variables in cats following IM sedation and blood donation. Due to its minimal impact on ECHO variables, AB may be a more desirable sedation protocol in this population of cats.

SEDATIVE AND CARDIORESPIRATORY EFFECTS OF INTRAMUSCULAR ALFAXALONE AND BUTORPHANOL AT TWO DOSAGES IN FERRETS (MUSTELA PUTORIUS FURO).

Veterinary care of ferrets often requires chemical restraint. This study hypothesized that IM alfaxalone and butorphanol would result in clinically useful sedation without clinically relevant cardiorespiratory effects. Twelve healthy 15-mo-old ferrets of equal sexes weighing 0.75 to 1.66 kg were enrolled. Using a prospective, blinded design, ferrets randomly received either IM alfaxalone 2.5 mg/kg and butorphanol 0.2 mg/kg (low dose [LD]) or IM alfaxalone 5 mg/kg and butorphanol 0.2 mg/kg (high dose [HD]) (n = 6/group). Sedation times and induction and recovery scores were recorded by a blinded observer. Anesthetic monitor placement was attempted in all recumbent ferrets, and physiologic parameters and reflexes were recorded every 5 min until return of spontaneous movement. Data were assessed for normality using a Shapiro-Wilk normality test and analyzed by two-sample t test or Mann-Whitney U test; one ferret in HD was excluded. Ferrets in LD and HD exhibited moderate and marked sedation, with one of six and four of five ferrets tolerating monitor placement, respectively. Mean ± SD time to first effects, recumbency, and recovery in LD and HD was 2.30 ± 1.13 and 2.054 ± 1.12 (P = 0.7240), 2.87 ± 1.25 and 2.72 ± 1.41 (P = 0.8529), and 65.43 ± 32.43 and 52.30 ± 13.19 (P = 0.4212), respectively. Median (range) duration of recumbency in LD and HD was 31.12 (25.58-115.72) and 35.47 (28.27-44.42) min (P = 0.3290), respectively. Among monitored ferrets, transient mild hypotension and hypoxemia were observed. Intramuscular alfaxalone 5 mg/kg with butorphanol 0.2 mg/kg provided clinically useful sedation in ferrets with mild transient cardiorespiratory derangements.

Feasibility, indications, and radiographically confirmed diagnoses of standing extremity cone beam computed tomography in the horse.

OBJECTIVE: To report on the feasibility, indications, and diagnostic yield of cone beam computed tomography (CBCT) of horses' extremities performed under standing sedation. STUDY DESIGN: Retrospective clinical case series. SAMPLE POPULATION: Fifty-nine CBCT examinations in 58 horses. METHODS: Examinations were categorized for indications for CBCT dependent on a suspicion, presence, or absence of a diagnosis prior to CBCT. The number of acquisitions per examination, total time for the examination, diagnostic score of each acquisition (diagnostic, diagnostic-compromised, nondiagnostic), and additional diagnostic information regarding preexisting diagnostic information were recorded. RESULTS: Three (median) acquisitions were performed per examination in a median study time of 14 minutes. In 24 of 33 cases with a suspected diagnosis, this diagnosis was confirmed or definitively refuted; in seven of 33 cases, the suspected diagnosis was refuted without a new diagnosis; and, in two of 33 cases, the suspected diagnosis could not be confirmed nor could a new diagnosis be made. In five of nine cases without a preexisting diagnosis, a diagnosis was established. In 16 cases with a diagnosis prior to CBCT, additional information was recorded, or a surgical plan was prepared. In 14 of 18 cases in which additional contrast techniques were used, additional information was gained. CONCLUSION: Standing CBCT of the horses' extremities is feasible and can produce diagnostic information in a timely fashion. CLINICAL SIGNIFICANCE: The results provide evidence of the practicality and diagnostic potential of standing CBCT of horses' extremities.

Professional dental cleaning in dogs: clinical routines among Swedish veterinarians and veterinary nurses.

BACKGROUND: Dental disease is very common in dogs and veterinary professional dental cleaning and examination, together with daily dental home care, is the foundation for good dental health. To our knowledge, no previous study has investigated professional dental cleaning routines in small animal veterinary practice. A validated questionnaire survey was distributed to all veterinarians and veterinary nurses with registered e-mail addresses in the Swedish national registry (veterinarians; n = 3657, veterinary nurses; n = 1650). Response rates were 32% for veterinarians (V) and 38% for veterinary nurses (VN). RESULTS: In total, 73% (V)/96% (VN) of respondents reported that professional dental cleaning was performed at their work place under general anesthesia, and 27% (V)/18% (VN) that dental cleaning was performed under sedation. Of the respondents, 43% (V)/96% (VN) considered regular dental cleaning under general anesthesia fairly or very important, and 49% (V)/47% (VN) stated that it was sometimes important for good dental health in dogs. A majority of respondents, 84% (V)/97% (VN), reported that dental extractions were performed at their clinic, and 72% (V)/90% (VN) had access to dental radiography equipment. CONCLUSION: A majority of Swedish veterinarians and veterinary nurses perform professional dental cleaning under general anesthesia with access to dental radiography equipment, in accordance with national and international recommendations. However, a considerable proportion of professional dental cleanings were performed under sedation only, and extractions performed without access to dental radiography equipment were common, suggesting several areas of improvement in the routines in Swedish veterinary clinics and hospitals. Our results clearly indicate the need for improved educational efforts to increase the awareness among veterinary health professionals regarding guidelines and official recommendations in canine dental care.

Feline procedural sedation and analgesia: When, why and how.

PRACTICAL RELEVANCE: Procedural sedation and analgesia (PSA) describes the process of depressing a patient's conscious state to perform unpleasant, minimally invasive procedures, and is part of the daily routine in feline medicine. Maintaining cardiopulmonary stability is critical while peforming PSA. CLINICAL CHALLENGES: Decision-making with respect to drug choice and dosage regimen, taking into consideration the cat's health status, behavior, any concomitant diseases and the need for analgesia, represents an everyday challenge in feline practice. While PSA is commonly perceived to be an uneventful procedure, complications may arise, especially when cats that were meant to be sedated are actually anesthetized. AIMS: This clinical article reviews key aspects of PSA in cats while exploring the literature and discussing complications and risk factors. Recommendations are given for patient assessment and preparation, clinical monitoring and fasting protocols, and there is discussion of how PSA protocols may change blood results and diagnostic tests. An overview of, and rationale for, building a PSA protocol, and the advantages and disadvantages of different classes of sedatives and anesthetics, is presented in a clinical context. Finally, injectable drug protocols are reported, supported by an evidence-based approach and clinical experience.

Sedative effects and pharmacokinetics of detomidine when administered intravenously and intravaginally as a gel in alpacas.

OBJECTIVES: To evaluate the sedative effects and pharmacokinetics of detomidine gel administered intravaginally to alpacas in comparison with intravenously (IV) administered detomidine. STUDY DESIGN: Randomized, crossover, blinded experiment. ANIMALS: A group of six healthy adult female Huacaya alpacas (70.3 ± 7.9 kg). METHODS: Alpacas were studied on two occasions separated by ≥5 days. Treatments were IV detomidine hydrochloride (70 µg kg-1; treatment DET-IV) or detomidine gel (200 µg kg-1; treatment DET-VAG) administered intravaginally. Sedation and heart rate (HR) were evaluated at intervals for 240 minutes. Venous blood was collected at intervals for 360 minutes after treatment for analysis of detomidine, carboxydetomidine and hydroxydetomidine using liquid chromatography-tandem mass spectrometry. Measured variables were compared between treatments and over time using mixed model analysis. Data are presented as the mean ± standard error of the mean, and a p value of <0.05 was considered significant. RESULTS: Onset of sedation was faster in treatment DET-IV (1.6 ± 0.2 minutes) than in treatment DET-VAG (13.0 ± 2.5 minutes). Time to maximum sedation was shorter in treatment DET-IV (8.3 ± 1.3 minutes) than in treatment DET-VAG (25 ± 4 minutes). Duration of sedation was not different between treatments. There was a significant linear relationship between sedation score and plasma detomidine concentration. HR was less than baseline for 60 and 125 minutes for treatments DET-IV and DET-VAG, respectively. The maximal decrease in HR occurred at 15 minutes for both treatments. The mean maximum plasma concentration of detomidine, time to maximum concentration and bioavailability for treatment DET-VAG were 39.6 ng mL-1, 19.9 minutes and 20%, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Detomidine administration at the doses studied resulted in moderate sedation when administered IV or intravaginally to alpacas.

Intramuscular alfaxalone and methadone with or without ketamine in healthy cats: effects on sedation and echocardiographic measurements.

OBJECTIVE: To evaluate the effect of alfaxalone and methadone administered intramuscularly (IM), with or without ketamine, on sedation and echocardiographic measurements in healthy cats. STUDY DESIGN: A randomized, blinded, clinical study. ANIMALS: A group of 24 client-owned cats. METHODS: Baseline echocardiographic evaluation (bEchoCG) was performed. Cats were given IM alfaxalone (2 mg kg-1) and methadone (0.3 mg kg-1) with (AMK group) or without (AM group) ketamine (1 mg kg-1). A sedation score (0-5, indicating none to good sedation) was assigned at 5 (T5), 10 (T10) and 15 (T15) minutes after IM injection. At T15, a second echocardiographic evaluation (sEchoCG) was performed. Data are shown as median (range). Significance was p < 0.05. RESULTS: Finally, 21 cats were included. Sedation score was significantly higher in the AMK (11 cats) than in the AM group (10 cats): 4 (1-5) versus 0.5 (0-4) at T5 (p = 0.003); 4 (1-5) versus 1.5 (0-5) at T10 (p = 0.043); and 4 (1-5) versus 2 (0-5) at T15 (p = 0.024). All echocardiographic measurements obtained were within reference ranges. Between the groups, aortic root area (p = 0.009) and end-diastolic aortic dimension (p = 0.011) were significantly higher in the AM group at bEchoCG and sEchoCG, respectively. Within each group, values at bEchoCG and sEchoCG showed no significant differences, except for pulmonary peak velocity (0.85 m second-1; p = 0.028) in the AMK group and ejection time (154 m second; p = 0.03) in the AM group; both variables decreased after sedation. CONCLUSIONS AND CLINICAL RELEVANCE: In this population of healthy cats, neither protocol produced clinically meaningful effects on the echocardiographic variables evaluated. Alfaxalone with methadone produced mild sedation, whereas the addition of 1 mg kg-1 ketamine induced adequate sedation for diagnostic procedures.

Effect of sedation or general anesthesia on elbow goniometry and thoracic limb circumference measurements in dogs with naturally occurring elbow osteoarthritis.

OBJECTIVE: To evaluate the effect of sedation or general anesthesia (GA) on elbow goniometry and thoracic limb circumference (TLC) measurements in dogs with elbow osteoarthritis (OA). STUDY DESIGN: Prospective study. ANIMALS: Twenty-four client-owned dogs with radiographically confirmed elbow OA. METHODS: Elbow goniometry and TLC measurements were made before and after either sedation or GA by using a hand-held goniometer and spring tension measuring tape, respectively. Observers were not allowed to review their pre-sedation or pre-GA measurements at the time of obtaining measurements on dogs under sedation or GA. Mixed analysis of variance models were used to compare elbow goniometry and TLC measurements before and after sedation or GA. RESULTS: Eleven and thirteen dogs were included in the sedation and GA groups, respectively. Mean elbow flexion decreased by 5° and 3° and mean elbow extension increased by 6° and 2° under sedation and GA, respectively. Total range of motion increased by 11° under sedation and by 5° under GA. Each of these changes was statistically significant (P < .05) except elbow extension under GA (P = .129). Sedation and GA did not influence TLC measurements (P > .05). CONCLUSION: Sedation or GA led to slight and similar increase in elbow flexion and extension but did not influence TLC measurements in dogs with elbow OA. CLINICAL SIGNIFICANCE: Sedation or GA can cause slight alterations to goniometric measurements in canine elbows with OA. The protocols used in this study for sedation and GA seem interchangeably acceptable for goniometry and TLC measurements in dogs with elbow OA.

Pharmacokinetics, sedation and hemodynamic changes following the administration of oral transmucosal detomidine gel in cats.

OBJECTIVES: The aim of this study was to describe the pharmacokinetics of oral transmucosal (OTM) detomidine gel in healthy cats and assess its effects on sedation and hemodynamic variables. METHODS: Eight adult cats weighing 4.12 kg ± 0.72 received 4 mg/m2 detomidine gel onto the buccal mucosa. Level of sedation, heart rate (HR), blood pressure (BP) and respiratory rate (f R) were assessed at predetermined intervals following administration. Blood samples for plasma detomidine concentrations and venous blood gas variables were collected from a medial saphenous catheter. Plasma detomidine concentrations were analyzed using ultra-high-pressure liquid chromatography with mass spectrometry detection, and pharmacokinetic estimates were obtained with compartmental methods. Data were analyzed using ANOVA and paired t-test or appropriate non-parametric tests. RESULTS: Sedation occurred in all cats, and was increased from baseline at 30 mins (P <0.001). Decreases in HR occurred from 15-60 mins, ranging from 140 to 165 beats per min (P <0.001). Blood glucose increased from 101 ± 12 mg/dl to 168 ± 27.3 mg/dl at 60 mins (P = 0.004). Systolic blood pressure decreased from baseline (139 ± 14.8 mmHg) to 103 ± 23.0 mmHg at 60 mins (P = 0.023). All changes abated by 120 mins. Emesis occurred in 7/7 cats within 2 mins of gel administration. Geometric mean (coefficient of variation) for clearance was 220.7 ml/min/kg (35.3 ml/min/kg), volume of distribution was 14.9 l/kg (39.9 l/kg) (both a function of bioavailability) and elimination half-life was 46.9 mins (16.0 mins). Maximum plasma concentrations of 10.5 ng/ml (35.5 ng/ml) detomidine occurred at 36.9 mins (21.5 mins). CONCLUSIONS AND RELEVANCE: OTM detomidine gel produced moderate sedation with minimal undesirable side effects in healthy cats, although emesis occurred in all cats. The pharmacokinetic profile supports short-term, minimally invasive sedation in this species. Further studies are warranted to assess its safety and feasibility for use in debilitated cats, or prior to general anesthesia.

Hemodynamic, respiratory and sedative effects of progressively increasing doses of acepromazine in conscious dogs.

OBJECTIVE: To evaluate the effects of progressively increasing doses of acepromazine on cardiopulmonary variables and sedation in conscious dogs. STUDY DESIGN: Prospective, experimental study. ANIMALS: A group of six healthy, adult, mixed-breed dogs weighing 16.5 ± 5.0 kg (mean ± standard deviation). METHODS: Dogs were instrumented with thermodilution and arterial catheters for evaluation of hemodynamics and arterial blood gases. On a single occasion, acepromazine was administered intravenously to each dog at 10, 15, 25 and 50 µg kg-1 at 20 minute intervals, resulting in cumulative acepromazine doses of 10 µg kg-1 (ACP10), 25 µg kg-1 (ACP25), 50 µg kg-1 (ACP50) and 100 µg kg-1 (ACP100). Hemodynamic data and sedation scores were recorded before (baseline) and 20 minutes after each acepromazine dose. RESULTS: Compared with baseline, all acepromazine doses significantly decreased stroke index (SI), mean arterial pressure (MAP) and arterial oxygen content (CaO2) with maximum decreases of 16%, 17% and 21%, respectively. Cardiac index (CI) decreased by up to 19% but not significantly. Decreases of 26-38% were recorded for oxygen delivery index (DO2I), with significant differences for ACP50 and ACP100. Systemic vascular resistance index (SVRI) and heart rate did not change significantly. No significant difference was found among acepromazine doses for hemodynamic data. After ACP10, mild sedation was observed in five/six dogs and moderate sedation in one/six dogs, whereas after ACP25, ACP50 and ACP100, moderate sedation was observed in five/six or six/six dogs. CONCLUSIONS AND CLINICAL RELEVANCE: In conscious dogs, acepromazine decreased MAP, SI, CaO2 and DO2I, but no significant dose effect was detected. SVRI was not significantly changed, suggesting that the reduction in MAP resulted from decreased CI. The ACP25, ACP50 and ACP100 doses resulted in moderate sedation in most dogs; ACP10 resulted in only mild sedation.

SEDATIVE, CARDIORESPIRATORY, AND THERMOREGULATORY EFFECTS OF ALFAXALONE ON BUDGERIGARS (MELOPSITTACUS UNDULATUS).

Alfaxalone is a neurosteroid anesthetic agent that has been extensively used in both human and veterinary medicine for more than 50 yr. Previous studies involving avian species demonstrated various dose ranges and multiple routes of administration. The aim of this study was to evaluate the short-term sedative, cardiorespiratory, and thermoregulatory effects of an intramuscular injection of alfaxalone on budgerigars (Melopsittacus undulatus). A crossover study was performed with a sample size of 10 male budgerigars, previously determined to be healthy based on physical examination. Alfaxalone was administered intramuscularly at two doses: 15 and 20 mg/kg. The lower dose resulted in mild to moderate sedation for 29 ± 5 min, whereas the higher dose resulted in moderate to profound sedation for 29 ± 7 min. A statistically significant decrease in heart rate was observed 2 min after administration of alfaxalone at 15 mg/kg; however, this finding was noted to be transient. A statistically significant decrease in respiratory rate was observed at 6 and 10 min after injection in both groups. Cloacal temperature measurement with a digital thermometer and eye temperature calculated from thermographic images demonstrated a decrease in body temperature over time but was not found to be statistically significant. Intramuscular use of alfaxalone proved to provide short-term sedation in budgerigars, with statistically significant but clinically mild cardiorespiratory effects. Due to a significant decrease in body temperature, active warming is recommended when using alfaxalone in budgerigars.

Blood glucose and insulin concentrations after alpha-2-agonists administration in horses with and without insulin dysregulation.

BACKGROUND: In metabolically stable horses, alpha-2-agonists suppress insulin secretion with transient hyperglycemia and rebound hyperinsulinemia. In horses with insulin dysregulation (ID), the effect of alpha-2-agonists has not been investigated; however, both the alpha-2-agonist-induced suppression of insulin secretion and rebound hyperinsulinemia could have clinical relevance. HYPOTHESIS/OBJECTIVES: In horses with ID, alpha-2-agonists will alter insulin and glucose dynamics. ANIMALS: Seven horses with ID and 7 control horses. METHODS: In this randomized crossover study, xylazine hydrochloride (1.1 mg/kg) or detomidine hydrochloride (30 µg/kg) were administered IV, and blood was collected for glucose and insulin concentrations at 0, 15, 30, 45, 60, 90, 120, 150, 180, and 300 minutes after administration. Horses received each drug in a random order with a 24-hour washout period between drugs. Percent change in glucose and insulin concentrations was compared between groups, drugs, and over time with P < .05 considered significant. RESULTS: A significant time-dependent effect of both alpha-2-agonists on glucose and insulin concentrations in control and ID horses was identified (P = .01 for all comparisons). There was no significant effect of sedative selection and endocrine status on blood glucose concentration in either group; however, in ID horses, xylazine administration resulted in severe rebound hyperinsulinemia whereas detomidine administration did not (P = .02). CONCLUSIONS AND CLINICAL IMPORTANCE: Alpha-2-agonists have a significant effect on glucose and insulin concentrations in horses. In ID horses, detomidine could minimize hyperinsulinemia when compared to xylazine.

Evaluation of subcutaneous administration of alfaxalone-midazolam and dexmedetomidine-midazolam for sedation of ball pythons (Python regius).

OBJECTIVE: To evaluate SC administration of alfaxalone-midazolam and dexmedetomidine-midazolam for sedation of ball pythons (Python regius). ANIMALS: 12 healthy juvenile ball pythons. PROCEDURES: In a randomized crossover study, each snake was administered a combination of alfaxalone (5 mg/kg [2.3 mg/lb]) and midazolam (0.5 mg/kg [0.23 mg/lb]) and a combination of dexmedetomidine (0.05 mg/kg [0.023 mg/lb]) and midazolam (0.5 mg/kg), SC, with a washout period of at least 7 days between protocols. Respiratory and heart rates and various reflexes and behaviors were assessed and compared between protocols. Forty-five minutes after protocol administration, sedation was reversed by SC administration of flumazenil (0.05 mg/kg) alone or in combination with atipamezole (0.5 mg/kg; dexmedetomidine-midazolam protocol only). Because of difficulties with visual assessment of respiratory effort after sedative administration, the experiment was repeated for a subset of 3 ball pythons, with plethysmography used to assess respiration. RESULTS: Both protocols induced a similar level of moderate sedation with no adverse effects aside from transient apnea. Cardiopulmonary depression was more profound, but time to recovery after reversal was significantly shorter, for the dexmedetomidine-midazolam protocol than for the alfaxalone-midazolam protocol. Plethysmographic findings were consistent with visual observations and suggested that snakes compensated for a decrease in respiratory rate by increasing tidal volume amplitude. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that both protocols induced clinically relevant sedation in ball pythons and should be useful for minor procedures such as venipuncture and diagnostic imaging. However, caution should be used when sedating snakes with compromised cardiopulmonary function. (J Am Vet Med Assoc 2020;256:573-579.