Sedative and cardiorespiratory effects of intramuscular administration of alfaxalone and butorphanol combined with acepromazine, midazolam, or dexmedetomidine in dogs

Anaesthetic mortality in dogs: A worldwide analysis and risk assessment

BACKGROUND

Ensuring patient safety during small animal anaesthesia is crucial. This study aimed to assess anaesthetic-related deaths in dogs globally, identify risks and protective factors and inform clinical practice.

METHODS

This prospective cohort multicentric study involved 55,022 dogs from 405 veterinary centres across various countries. Data on anaesthesia-related deaths from premedication to 48 hours post-extubation were collected. Logistic regression was used to analyse patient demographics, American Society of Anesthesiologists (ASA) classification, procedure type and anaesthetic drugs used.

RESULTS

Anaesthetic-related mortality was 0.69%. Most deaths occurred postoperatively (81%). Age, obesity and a higher ASA classification score were associated with increased mortality. Urgent procedures, non-urgent but unscheduled anaesthesias and short procedures also had higher mortality. Some sedatives, systemic analgesics, hypnotics and the use of locoregional anaesthesia were linked to a decrease in mortality.

LIMITATIONS

The limitations of the study include the non-randomised sample, potential selection bias, lack of response rate quantification, variable data quality control, subjectivity in classifying causes of death and limited analysis of variables.

CONCLUSION

Careful patient evaluation, drug selection and monitoring can be associated with reduced mortality. These findings can be used to develop guidelines and strategies to improve patient safety and outcomes. Further research is needed to refine protocols, enhance data quality systems and explore additional risk mitigation measures.

A dose characterization study evaluating the pharmacodynamics and safety of a concentrated alfaxalone solution (4%) as an intramuscular sedative in dogs

Alfaxalone is a commonly employed veterinary anaesthetic induction and sedation agent. A 4% w/v preserved, aqueous formulation of alfaxalone 'RD0387' (A4%) has recently been developed. To evaluate the sedative effects of A4%, three doses, 5 mg kg-1 (A5); 7.5 mg kg-1 (A7.5) and 10 mg kg-1 (A10) were administered intramuscularly into the epaxial musculature of six healthy adult mixed-breed dogs in an experimental, randomized, blinded, crossover study. Sedation time variables, quality of sedation (including onset of sedation and recovery), physiological variables, response to cephalic vein catheterization and frequency of undesirable events were recorded. Continuous variables were analysed between treatments (one-way ANOVA or restricted maximum likelihood modelling) and within treatments compared with baseline (Tukey's test). Categorical data were analysed between treatments (Kruskal-Wallis' test) and within treatments from baseline (Dunn's test). Significance was set at p < .05. All dogs became sedated (laterally recumbent) and sedation onset was significantly faster in groups A7.5 (9.8 ± 5.3 min) and A10 (9.1 ± 5.6 min) compared to A5 (25.6 ± 16.1 min) (p = .033, p = .027, respectively). Duration of sedation was significantly longer in A10 (168.5 ± 70.6 min) and A7.5 (143.8 ± 58 min) compared to A5 (63.8 ± 28.2 min) (p = .005 and p = .003, respectively). Dogs in A10 had a superior quality of onset of sedation compared to A5 (p = .028). Sedation scores and quality of recovery from sedation were not significantly different between doses. Two dogs (2/6) in A5 were insufficiently sedated for cephalic catheterization. Ataxia was the most frequently observed undesirable event with an overall frequency of 78% (14/18) and 89% (16/18) during sedation onset and recovery, respectively. Overall, A4% administered IM in dogs at 7.5 and 10 mg kg-1 resulted in sufficient sedation for IV catheterization in dogs. To improve the speed and quality of the sedation, it is recommended that future research focuses on combining A4% with other sedative or analgesic drugs.

Sedation Quality and Cardiorespiratory, Echocardiographic, Radiographic and Electrocardiographic Effects of Intramuscular Alfaxalone and Butorphanol in Spanish Greyhound Dogs

The quality of sedation and changes in cardiorespiratory variables after the intramuscular administration of alfaxalone and butorphanol in Spanish greyhound dogs were evaluated. Twenty-one adult dogs were included. The dogs received alfaxalone (2 mg/kg) and butorphanol (0.2 mg/kg) intramuscularly. Sedation scoring, cardiorespiratory parameters (including blood gas analysis), echocardiography, thoracic radiography and electrocardiography were performed before sedation and 30 min after drug administration. Moderate sedation was observed, and side effects, such as tremors, nystagmus and auditory hyperesthesia, were noticed. Statistically significant changes in heart rate, invasive blood pressure, pH, arterial saturation of O2 and partial pressure of O2 and CO2 were found. Echocardiographic variables, including end-diastolic volume, left ventricular diameter in diastole, aortic and pulmonic flow, diastolic transmitral flow and left atrial/aortic ratio, and electrocardiography parameters, including PQ interval and QT interval, showed statistically significant changes. In conclusion, the intramuscular administration of alfaxalone and butorphanol to healthy dogs produced moderate sedation with mild cardiorespiratory, echocardiographic and electrocardiographic changes, without alterations in cardiac size on radiographic images.

Anesthetic Considerations in Dogs and Cats with Diabetes Mellitus

Understanding the effects of diabetes and hyperglycemia on hydration, acid-base status, and immune function is paramount to safely anesthetizing diabetic cats and dogs. Preoperative stabilization of glucose concentrations, hydration, and electrolyte imbalances is key to minimizing morbidity and mortality. Blood glucose monitoring perioperatively will help guide insulin and dextrose administration. Specific anesthetic considerations, and peri-anesthetic management of animals with diabetes mellitus, including anesthetic drugs and recommended insulin protocols are discussed.

Clinical review of the pharmacological and anaesthetic effects of alfaxalone in dogs

This clinical review summarises the pharmacological and anaesthetic properties of alfaxalone in the dog. Available pharmacokinetic-pharmacodynamic data and factors affecting the induction dose have been reported. Furthermore, quality of induction and recovery after alfaxalone administration, the use of alfaxalone for total intravenous anaesthesia, and its effects on the cardio-respiratory system, on laryngeal motion, on intraocular pressure and tear production have been evaluated. Finally, the use of alfaxalone in dogs undergoing caesarean section and the effect of intramuscular alfaxalone administration have been considered.