The time required to achieve endotracheal intubation in dogs: a comparison of veterinary students and qualified veterinary surgeons

ObjectiveTo determine whether final year veterinary students take longer to perform endotracheal intubation than qualified veterinary surgeons.Study designObservational cohort study.AnimalsA total of 38 healthy mesocephalic dogs undergoing general anaesthesia for a clinical purpose unrelated to this study.MethodsTime to successful endotracheal intubation, measured from termination of intravenous induction drug administration to confirmation of endotracheal intubation, was recorded for two groups: final year veterinary students (group S) and qualified veterinary surgeons (group V). Animal age, breed and anaesthetic induction agent were also recorded. Following normality testing the groups were compared for each variable using the Student’s t test or Mann–Whitney U test where appropriate. The level of significance was defined as p < 0.05. Timed data are presented as median and interquartile range.ResultsTime to successful intubation was 54.2 (31.3) seconds in group S and 11.7 (8.5) seconds in group V, the difference being significant (p < 0.001). There was also a significant difference between groups for animal age (p = 0.036) but not for breed (p = 0.573) or induction agent (p = 0.239).Conclusionsand clinical relevance Veterinary students take longer to achieve successful endotracheal intubation of anaesthetized healthy dogs compared with qualified veterinary surgeons. To mitigate any additional risk of dogs developing hypoxaemia, it is recommended that a 55 second time limit is set after which the supervisor intervenes and takes over the intubation procedure. Preoxygenation may be used as an additional mitigation strategy.     

Cross-sectional survey of pet ownership,veterinary service utilisation,and pet-related expenditures in New Zealand

ABSTRACT

Aims: To describe the demographics of and predictors for pet ownership, reasons for visiting a veterinarian, and pet-related expenditure in pet owners in New Zealand.

Methods: A cross-sectional online survey was conducted from 18–22 June 2015 using a permission-based panel of New Zealand residents aged ≥18 years. Questions included demographics of respondents, number of pets and reasons for owning or not owning pets, number of visits and reasons for visiting a veterinarian, and pet-related expenditure.

Results: Of the 1,572 respondents who completed the survey, 1,013 (64.4%) owned ≥1 pet. Of these, 443 owned dogs, 696 cats, 32 horses, 103 birds, 55 rabbits, and 159 owned fish. Companionship was the most common reason for getting dogs, cats, and birds; horses were mostly owned as a hobby, rabbits to provide fun for children, and fish as a source of relaxation. The majority of dog, cat, and rabbit owners considered their pets to be family members; horse owners almost equally considered their horses a hobby or a family member. The odds of pet ownership increased for respondents from a rural region, having a higher household income, having children and being female. Overall, 711/1,013 (70.2%) pet-owning respondents had taken ≥1 animal to the veterinarian in the previous year, with the most common reasons being for vaccination or annual check-ups or health issues. Respondents who considered their pets trusted companions, had a higher income, and owned dogs or cats compared with other species, were most likely to have taken their pet to a veterinarian. The greatest pet-related expenditure for all species was food. The median yearly veterinary expenditure was $200–499 by dog owners, $100–199 by cat owners, and <$100 by horse, bird, rabbit, and fish owners. The best source of information for pet-related issues was considered to be veterinarians by 724/1,001 (72.3%) owners, and the internet by 509/1,001 (50.8%) owners.

Conclusions: Among survey respondents, pet ownership was common and pets filled a variety of roles in the household. Pet owners reported spending considerable amounts of money on their pets each year, but some of them may be underutilising veterinary services despite veterinarians being considered as valuable sources of information about pet-related issues.     

Risk of burnout and depression: A survey of veterinary anaesthesia specialists in-training during COVID-19

ObjectiveTo investigate risk, risk factors and effects on adherence to adequate clinical standards, of burnout and depression in veterinary anaesthesia residents.Study designClosed online cross-sectional survey study.Study populationA sample of 89 residents registered to the European and/or the American Colleges of Veterinary An (ae)sthesia and Analgesia out of a total of 185.MethodsA link to access an online questionnaire, which included the Maslach Burnout Inventory-Human Services Survey (MBI-HSS), the Harvard National Depression Screening Day Scale (HANDS) and 28 questions developed to assess adherence to adequate clinical standards, was sent by email to 185 residents. The three components of the MBI-HSS namely emotional exhaustion (EE), depersonalization and reduced personal accomplishment were analysed separately. Analysis of proportions and two-step regression statistical modelling were used for data analysis, and p values < 0.05 were considered statistically significant.ResultsThe response rate was 48%. Based on HANDS and MBI-HSS scores, 49% of the residents were at high risk of both depression and burnout. These residents expressed greater concern of delivering inadequate animal care (p < 0.001), of decreased quality of supervision during COVID-19 (p = 0.038) and of negative impact of the pandemic on their training programme (p = 0.002) than residents at low-to-moderate risk. Working in a clinical environment for ≥ 60 hours/week was a risk factor for both depression (p = 0.016) and EE (p = 0.022), while female sex was a risk factor for EE only (p = 0.018).Conclusions and clinical relevanceA large proportion of residents is at high risk of depression and burnout, a scenario likely worsened by the pandemic. The findings of this study suggest that reducing the clinical workload and increasing the level of support and supervision may help to improve residents’ mental health.     

An investigation into the detection of the pulse in conscious and anaesthetized dogs

ObjectivesTo record the success rate of veterinary professionals and students at identifying the pulse in conscious and anaesthetized dogs. To explore the influence of clinical experience, pulse location, anaesthesia and likely confounding variables on the success of pulse palpation.Study designProspective, observational, randomized study.AnimalsA total of 54 client-owned dogs scheduled for general anaesthesia.MethodsFor each dog, three participants (senior anaesthetist, anaesthesia resident/nurse, veterinary student/animal care assistant) attempted pulse palpation at three locations (femoral, radial and dorsal pedal pulse) in conscious and anaesthetized dogs. The time to pulse palpation was measured with a stopwatch for each attempt and data were modelled using a multivariate Cox regression survival analysis (significance p < 0.05).ResultsThe overall success rate of pulse palpation was 77%, with a median time of 10.91 seconds (interquartile range 9.09 seconds). Success rate was lower in conscious dogs (67%) than in anaesthetized dogs (87%). There was a 77% lower likelihood of success at the radial than at the femoral pulse [hazard ratio (HR) 0.23, 95% confidence interval (CI) 0.38–0.69, p < 0.001]. Veterinary students/animal care assistants had a 71% lower likelihood of success than senior anaesthetists (HR 0.29, 95% CI 0.22–0.39, p < 0.001). Age, weight and American Society of Anesthesiologists physical status had no significant influence. Premedication/anaesthetic drugs, heart rate or mean arterial pressure had no significant influence on the time to pulse palpation in anaesthetized dogs. The median time to palpation was less than 10 seconds for all experience groups at the femoral location.ConclusionsPalpation of the femoral location had the greatest likelihood of success with the least amount of time. Monitoring the femoral pulse during induction of anaesthesia is suggested as a method for confirming spontaneous circulation. Pulse palpation improves with clinical experience.     

The Canine Postamputation Pain (CAMPPAIN) initiative: a retrospective study and development of a diagnostic scale

ObjectiveTo develop a scale to diagnose and assess the severity of postamputation pain (PAP) in dogs.Study designSingle-center retrospective study.AnimalsA total of 66 dogs that underwent thoracic or pelvic limb amputation and 139 dogs that underwent tibial plateau leveling osteotomy (TPLO) at a veterinary teaching hospital.MethodsAn online survey regarding postoperative behavioral changes was sent to owners. Categorical, multiple-choice responses were entered into a univariable logistic regression model and tested for association with amputation using the Wald test. If p < 0.2, variables were forwarded to a multivariable logistic regression model for manual build. Model simplicity and predictive ability were optimized using the area under the receiver operating curve (AUROC) characteristic, and model calibration was assessed using the Hosmer–Lemeshow test. The selected model was converted to an integer scale (0–10), the Canine Postamputation Pain (CAMPPAIN) scale. Univariable logistic regression related each dog’s calculated score to the probability of PAP.ResultsMultivariable logistic regression identified four independent predictors of PAP (p < 0.05): 1) restlessness or difficulty sleeping, 2) episodes of panic or anxiety, 3) sudden vocalization, and 4) compulsive grooming of the residual limb. Score AUROC was 0.70 (95% confidence interval = 0.63–0.78) with good calibration (Hosmer–Lemeshow statistic p = 0.82). A score of 2 corresponded to a risk probability of 0.5. Taking a score ≥ 2 to indicate PAP, score specificity and sensitivity were 92.1% and 36.4%, respectively. When this score was used to diagnose PAP, prevalence was 36.4% (24/66) and 7.9% (11/139) in the amputation and TPLO groups, respectively.Conclusions and clinical relevancePostamputation pain is characterized by specific postoperative behaviors and appears to affect approximately one-third of canine amputees. The CAMPPAIN scale generated from these data could facilitate diagnosis, treatment and further study of PAP but requires external validation.     

Improvement to the subjective well-being of pet ownership may have positive psychological influence during COVID-19 epidemic

The COVID-19 epidemic and government intervention measures may have adverse effects on people's mental health. To explore the influence of pets on the intervention of people's psychological problems during the COVID-19 epidemic, an online survey was carried out between April 9 and April 29, 2020. A total of 756 participants replied to this questionnaire. Mental health variables were assessed, and the comparison of behavior changes among pet owners and pets on positive mental well-being during COVID-19 epidemic. Comparative analysis was performed; compared with individuals without pets (n = 575), pet owners (n = 181) had a higher prevalence of insomnia (p = 0.006). Living in Wuhan city was a risk factor for people with psychological stress (p < 0.05). Dog owners exhibited lower than average scores of insomnia and uncertainty of infection than cat owners (p = 0.004). People with more than one pet exhibited lower than average scores of depression than having one pet (p = 0.040). For analysis of psychological effects of pets on people, the role of pets in subjective feeling and positive psychological changes of pet owner was significantly different. Pet owners relieve that psychological pressure through behavioral changes towards their pets in early stage. Pets provided positive subjective well-being and psychological effects for their owners.     

Cross-sectional survey of sleep,fatigue and mental health in veterinary anaesthesia personnel

ObjectiveTo evaluate the sleep quality, prevalence of fatigue and depressive symptoms in veterinary anaesthesia personnel.Study designAnonymous online voluntary survey.MethodsSleep quality, fatigue, depressive symptoms and self-perceived burnout were scored using the Pittsburgh Sleep Quality Index (PSQI), Fatigue Severity Scale (FSS), Patient Health Questionnaire-9 (PHQ-9) and single-item burnout measure, respectively. Demographic data and questions about work-related fatigue, out-of-hours duty, transport and rest periods were included. PSQI, FSS and PHQ-9 scores were compared using Spearman rank correlation tests.ResultsResponses from 393 participants were obtained from an estimated population of 1374 including diplomates of the American and European Colleges of Veterinary An(a)esthesia and Analgesia (43.9%), residency-trained veterinarians (15.6%), residents-in-training (13.8%) and veterinary technicians and nurses (12.0%), from 32 countries. Most were employed in clinical university teaching hospitals (54.2%) or clinical private practice (41.5%).PSQI scores > 5 were reported by 71.2% of respondents, with 52.4% reporting insufficient sleep to meet their job demands. Many showed high or borderline fatigue (56.4%), and 74.7% reported mistakes due to work-related fatigue. Major depressive symptoms (PHQ-9 score ≥ 10) were found in 42.7%, with 19.2% reporting they had thought about suicide or self-harm in the previous 2 weeks. Over half (54.8%) met the criteria for burnout and more veterinary nurses and technicians suffered from burnout than other roles, with 79.6% of this group affected (p < 0.001).Scores for PSQI and FSS [r (388) = 0.40, p < 0.001]; PSQI and PHQ-9 [r (389) = 0.23, p < 0.001]; and FSS and PHQ-9 [r (387) = 0.24, p < 0.001] were all positively correlated.Conclusions and clinical relevanceThis survey demonstrates a high prevalence of poor sleep, fatigue, depressive symptoms and burnout in veterinary anaesthesia personnel, and more should be done to improve the health of those in the profession.     

Anesthetic and analgesic techniques used for dogs undergoing ovariohysterectomies in general practice in the United States

ObjectiveTo acquire information about anesthesia and analgesia protocols used by United States (US) veterinarians in primary care practices when performing routine ovariohysterectomy in dogs.Study designCross-sectional survey.PopulationPrimary care veterinarians in the US.MethodsAn online anonymous survey, originally created in New Zealand, was modified with permission and made available to Veterinary Information Network (VIN) members. The survey asked questions about performing ovariohysterectomy in healthy adolescent dogs in the categories of preanesthetic evaluation, premedication and induction protocols, maintenance protocols and monitoring equipment, and postoperative analgesic and sedation protocols and pain assessments.ResultsA total of 1213 US veterinarians completed the survey. Respondents (n; %) reported performing preoperative laboratory tests [packed cell volume (135; 11%), complete blood cell count (889; 73%) and biochemistry panels (1057; 87%)] and preanesthetic examinations on the morning of surgery (1083; 90%). The most commonly administered drugs for premedication were acepromazine (512; 42%), hydromorphone (475; 39%) or butorphanol (463; 38%), with propofol (637; 67%) for induction of anesthesia and isoflurane (882; 73%) for maintenance of anesthesia. Most veterinarians reported placing intravenous catheters (945; 78%), administering electrolyte solutions (747; 67%) and providing heat support (1160; 96%). Perioperative and postoperative analgesia included local anesthetics (545; 45%), opioids (844; 70%) and non-steroidal anti-inflammatory drugs (NSAIDs) (953; 79%); NSAIDs were dispensed for home use (985; 81%). Dogs were most frequently discharged on the day of surgery (1068; 88%) and the owners were contacted (914; 75%) for follow-up within 1–2 days.Conclusions and clinical relevanceAnesthetic management for routine ovariohysterectomy in dogs varies among US veterinary VIN members. Information from this study is useful for all veterinarians for comparison with their practice management and for teachers of veterinary anesthesia to continue to emphasize options for analgesia.     

The prevention of undesirable behaviors in dogs: effectiveness of veterinary behaviorists' advice given to puppy owners

The management of puppies is considered of great importance in raising well-behaved adult dogs. This research aimed to assess the effectiveness of advice provided by a veterinary behaviorist regarding puppy-raising practices.Forty-six puppy owners received advice by a veterinary behaviorist concerning puppy raising during the puppy's first visit to a veterinarian. A control group was composed of 43 different dogs whose owners were not counseled by a veterinary behaviorist during the puppy's first veterinary visit. Owners were interviewed about their dog's behaviors at the time of their 1-year booster vaccination visit. The 89 dogs were clinically healthy, between 11 and 18 months old, 53% females and 47% males, of various or mixed breeds.Dogs whose owners received advice displayed less undesirable behaviors than the control group, such as: house soiling (2% vs 23%; χ² = 19.50; P < .01), mounting (26% vs 49%; χ² = 12.11; P < .05), nonstop playing (0% vs 12%; Fisher's exact test P < .05), mouthing of people (11% vs 37%; χ² = 7.15; P < .01), begging for food (17% vs 42%; χ² = 5.31; P < .05), or demanding food from the table (0% vs 12%; Fisher's exact test P < .05). Moreover, the experimental group showed less aggressive behaviors toward unknown people (26% vs 2%; Fisher's exact test P < .01) and dogs (16% vs 2%; Fisher's exact test P < .05).The advice provided was effective in diminishing the incidence of undesirable behaviors in the dogs studied. The positive effect of a behaviorist's advice is remarkable given that the puppies in the experimental group had remained with their mother and littermates for less than 2 months, which is believed to be a high-risk condition for development of behavioral disorders.     

Clinical efficacy of dexmedetomidine combined with lidocaine for femoral and sciatic nerve blocks in dogs undergoing stifle surgery

ObjectiveTo evaluate the effects of dexmedetomidine administered perineurally or intramuscularly (IM) on sensory, motor function and postoperative analgesia produced by lidocaine for sciatic and femoral nerve blocks in dogs undergoing unilateral tibial tuberosity advancement surgery.Study designProspective, blinded, clinical study.AnimalsA group of 30 dogs.MethodsDogs were anaesthetized with acepromazine, propofol and isoflurane in oxygen/air. Electrolocation-guided femoral and sciatic nerve blocks were performed: group L, 0.15 mL kg^–1 2% lidocaine (n = 10); group LD_loc, lidocaine and 0.15 μg kg^–1 dexmedetomidine perineurally (n = 10); group LD_sys, lidocaine and 0.3 μg kg^–1 dexmedetomidine IM (n = 10). After anaesthesia, sensory blockade was evaluated by response to forceps pinch on skin innervated by the saphenous/femoral, common fibular and tibial nerves. Motor blockade was evaluated by observing the ability to walk and proprioception. Analgesia was monitored with Short Form of Glasgow Composite Pain Scale for up to 4 hours after extubation. Methadone IM was administered as rescue analgesia. Data were analysed by linear mixed effect models and Kaplan-Meier test (p < 0.05).ResultsMedian duration of the sensory blockade for all nerves was longer (p < 0.001) for group LD_loc than for groups L and LD_sys and was longer (p = 0.0011) for group LD_sys than for group L. Proprioception returned later (p < 0.001) for group LD_loc [285 (221–328) minutes] compared with group L [160 (134–179) minutes] or LD_sys [195 (162–257) minutes]. Return of the ability to walk was similar among all groups. Dogs in group LD_loc required postoperative rescue analgesia later (p = 0.001) than dogs in groups LD_sys and L.Conclusions and clinical relevanceDexmedetomidine administered perineurally with lidocaine prolonged sensory blockade and analgesia during the immediate postoperative period. Systemic dexmedetomidine also prolonged the sensory blockade of perineural lidocaine.     

Comparison of sedative and some cardiopulmonary effects of intramuscular medetomidine or medetomidine–tramadol in dogs

ObjectiveTo evaluate the clinical and physiologic effects of intramuscular (IM) administration of medetomidine with and without tramadol in dogs.Study designProspective experimental study.AnimalsA group of eight mixed breed dogs of both sexes, aged 1–2 years, weighing 16.0 ± 0.6 kg.MethodsEach dog was studied twice at ≥1 week interval. Medetomidine (5 μg kg^–1; treatment M) was administered IM alone or with tramadol (4 mg kg^–1; treatment MT). Sedation was scored by a system that included vocalization, posture, appearance, interactive behaviors, resistance to restraint and response to noise. Times from drug administration to ataxia, impaired walking, head drop, sternal and lateral position and standing were recorded. Sedation score, heart rate, respiratory rate, rectal temperature, end-tidal carbon dioxide (Pe′CO₂), hemoglobin oxygen saturation and mean noninvasive blood pressure were recorded and compared 15 minutes before and 15, 30 and 45 minutes after drug administration.ResultsDogs administered MT had higher sedation scores than dogs administered M at 30 and 45 minutes after drug administration (p < 0.05). Times to ataxia, impaired walking, head drop and sternal recumbency were not different between the treatments. Time to lateral recumbency was longer in M than in MT (21.1 ± 1.0 versus 17.6 ± 0.7 minutes, respectively; p < 0.05). Time to standing was longer in MT than in M (67.9 ± 1.4 versus 54.5 ± 1.9 minutes, respectively; p < 0.001). Measured physiological variables did not differ between the treatments, with the exception of Pe′CO₂, which was higher in MT than in M at all post-treatment evaluation times (p < 0.001).Conclusions and clinical relevanceTramadol combined with medetomidine resulted in greater sedation scores (deeper sedation) than medetomidine alone in dogs, and minimal adverse changes in the physiologic variables were measured.     

Training satisfaction and well-being among veterinary anaesthesia residents: time for action

ObjectiveTo explore the satisfaction and well-being experienced by anaesthesia residents during their training, and to investigate factors that may have influenced their experiences.Study designCross-sectional online anonymous voluntary survey.Sample populationA total of 150 (of approximately 600 canvassed) former veterinary anaesthesia residents.MethodsParticipants were invited to complete an internet-based survey regarding the satisfaction and well-being experienced during their residency. Multiple choice, categorical, dichotomous, Likert-type rating scales and slider questions were used to investigate five domains (demographic, working conditions, educational environment, training satisfaction, well-being). Sampling adequacy, questionnaire reliability and participant responses were investigated by Kaiser-Meyer-Olkin (KMO) indices, Cronbach’s α and standard statistical techniques, respectively (p < 0.05).ResultsThe questionnaire demonstrated good sampling adequacy (median KMO index 0.74; range 0.51–0.89) and high item ‘reliability’ (α = 0.82–0.94). Of the 150 responders, (25% participation rate) 62% were satisfied, 14% were neutral and 24% were dissatisfied with their residency training; 60.6% would do the residency again, 39.3% would not or were unsure. Sex and age did not correlate with training satisfaction (p > 0.05). Salary/stipend was considered inadequate by 70% of responders; 66% received no on-call supplement. Greater supervisory input, a good working environment and extra income when on-call were positively correlated with training satisfaction (p < 0.01). The majority (94.6%) of trainees suffered from at least one medical condition during their residency, with fatigue, sleep disturbance or anxiety reported by > 62%.ConclusionsAlthough a quarter of responders were dissatisfied with their residency, several modifiable factors were identified, particularly with respect to supervisors’ input, working environment and pay, which could inform improvements for future residency programmes. Most trainees experienced negative health impacts; however, this parallels the general situation in both the medical and veterinary professions, which requires greater attention from the supervisors, trainees and colleges.     

Evaluation of cardiovascular effects of intramuscular medetomidine and a medetomidine–vatinoxan combination in Beagle dogs: A randomized blinded crossover laboratory study

ObjectiveTo compare the cardiovascular effects of a combination of medetomidine and vatinoxan (MVX) versus medetomidine (MED) alone administered intramuscularly (IM) and to determine whether heart rate (HR) can be used as a surrogate for cardiac output (CO) after the use of medetomidine with or without vatinoxan.Study designA randomized, blinded, experimental, crossover study.AnimalsA group of eight healthy Beagle dogs aged 4.6 (2.3–9.4) years and weighing 12.9 (9–14.7) kg, median (range).MethodsEach dog was injected with 1 mg m^–2 medetomidine with or without 20 mg m^–2 vatinoxan IM with a washout period of 7 days. Cardiovascular data and arterial and mixed venous blood gas samples were collected at baseline, 5, 10, 15, 20, 35, 45, 60, 90 and 120 minutes after treatment administration. CO was measured at all time points via thermodilution. Differences between treatments, period and sequence were evaluated with repeated measures analysis of covariance and the relationship between HR and CO was assessed with a repeated measures analysis of variance; p values < 0.05 were deemed significant.ResultsThe CO was 47–96% lower after MED than after MVX (p < 0.0001). Increases in systemic, pulmonary arterial and right atrial pressures and oxygen extraction ratio were significantly higher after MED than after MVX (all p < 0.0001). HR was significantly lower after MED and the linear relationship to CO was significant (p < 0.0001).Conclusions and clinical relevanceOverall, MED affected the cardiovascular system more negatively than MVX, and the difference in cardiovascular function between the treatments can be considered clinically relevant. HR was linearly related to CO, and decreases in HR reflected cardiac performance for dogs sedated with medetomidine with or without vatinoxan.     

Retrospective evaluation of the impact of hypoxemia during thoracic surgery in dogs on outcome: a multicenter analysis of 94 cases

ObjectiveTo investigate the statistical association of severe intraoperative hypoxemia in thoracic surgery with mortality, postoperative hospitalization times and cost of care.Study designRetrospective study.AnimalsDogs that underwent thoracic surgery in three veterinary hospitals between October 1, 2018 and October 1, 2020.MethodsAnesthesia and hospitalization records from 112 dogs were reviewed and 94 cases met inclusion criteria. Recorded data included signalment, disease etiology, pulmonary or extrapulmonary nature of disease, surgical procedure performed, episodes of severe intraoperative hypoxemia defined as a pulse oximetry reading (SpO₂) <90% of 5 minutes or longer duration, survival to discharge, time from extubation to hospital discharge and total invoice cost for clinical visit. Dogs were divided into two groups, those that experienced severe hypoxemia (group A) and those in which SpO₂ reading <90% was not observed throughout the procedure (group B).ResultsGroup A had a greater risk of mortality (odds ratio 10.6, 95% confidence interval 1.9–106.7; p = 0.002), prolonged hospitalization (median 62 hours versus 46 hours; p = 0.035) and more expensive cost of care (median US$10,287 versus $8506; p = 0.056) than group B. No significant difference was found for the type of surgical procedure or pulmonary versus extrapulmonary nature of disease.Conclusions and clinical relevanceSevere intraoperative hypoxemia was statistically associated with an increased risk of mortality and longer postoperative hospitalization times. Although not achieving statistical significance, there was a trend toward increased costs to the client for animals with intraoperative hypoxemia.     

Prophylactic use of a lidocaine constant rate infusion versus saline in dogs undergoing balloon valvuloplasty for management of pulmonic stenosis: A randomized control trial

ObjectiveTo evaluate the effect of a prophylactic lidocaine constant rate infusion (CRI) on the incidence and malignancy of catheter-induced ventricular ectopic complexes (VECs) during balloon valvuloplasty for management of pulmonic stenosis in dogs.Study designSingle-centre, prospective, randomized study.AnimalsClient-owned dogs (n = 70) with pulmonic stenosis.MethodsDogs were randomly assigned to one of two anaesthetic protocols: administration of lidocaine 2 mg kg^–1 bolus followed by a CRI (50 μg kg^–1 minute^–1; group LD) or a saline placebo (group SL) during balloon valvuloplasty. All dogs were premedicated with methadone (0.3 mg kg^–1) intramuscularly and a digital three-lead Holter monitor was applied. Anaesthetic co-induction was performed with administration of alfaxalone (2 mg kg^–1) and diazepam (0.4 mg kg^–1), and anaesthesia was maintained with isoflurane vaporised in 100% oxygen. CRIs were started on positioning of the dog in theatre and discontinued as the last vascular catheter was removed from the heart. All dogs recovered well and were discharged 24 hours postoperatively. Blinded Holter analysis was performed by an external veterinary cardiologist using commercially available dedicated analysis software; p < 0.05.ResultsOf the 70 dogs enrolled in the study, 61 were included in the final analysis: 31 in group LD and 30 in group SL.There was no significant difference between sinus beats (p = 0.227) or VECs (p = 0.519) between groups. In group LD, 19/31 (61.3%) dogs had a maximum ventricular rate ≥250 units and 20/30 (66.7%) dogs in group SL (p = 0.791).Conclusion and clinical relevanceIn this study, the use of a prophylactic lidocaine bolus followed by CRI in dogs undergoing balloon valvuloplasty for management of pulmonic stenosis did not significantly decrease the incidence nor the malignancy of VECs during right heart catheterization compared with a saline CRI.     

Pharmacokinetics and pharmacodynamics of hydromorphone after intravenous and intramuscular administration in horses

ObjectiveTo compare the pharmacokinetics and pharmacodynamics of hydromorphone in horses after intravenous (IV) and intramuscular (IM) administration.Study designRandomized, masked, crossover design.AnimalsA total of six adult horses weighing [mean ± standard deviation (SD))] 447 ± 61 kg.MethodsHorses were administered three treatments with a 7 day washout. Treatments were hydromorphone 0.04 mg kg^⁻1 IV with saline administered IM (H-IV), hydromorphone 0.04 mg kg^⁻1 IM with saline IV (H-IM), or saline IV and IM (P). Blood was collected for hydromorphone plasma concentration at multiple time points for 24 hours after treatments. Pharmacodynamic data were collected for 24 hours after treatments. Variables included thermal nociceptive threshold, heart rate (HR), respiratory frequency (f_R), rectal temperature, and fecal weight. Data were analyzed using mixed-effects linear models. A p value of less than 0.05 was considered statistically significant.ResultsThe mean ± SD hydromorphone terminal half-life (t_1/2), clearance and volume of distribution of H-IV were 19 ± 8 minutes, 79 ± 12.9 mL minute^⁻1 kg^⁻1 and 1125 ± 309 mL kg^⁻1. The t_1/2 was 26.7 ± 9.25 minutes for H-IM. Area under the curve was 518 ± 87.5 and 1128 ± 810 minute ng mL^⁻1 for H-IV and H-IM, respectively. The IM bioavailability was 217%. The overall thermal thresholds for both H-IV and H-IM were significantly greater than P (p < 0.0001 for both) and baseline (p = 0.006). There was no difference in thermal threshold between H-IV and H-IM. No difference was found in physical examination variables among groups or in comparison to baseline. Fecal weight was significantly less than P for H-IV and H-IM (p = 0.02).Conclusions and clinical relevanceIM hydromorphone has high bioavailability and provides a similar degree of antinociception to IV administration.IM hydromorphone in horses provides a similar degree and duration of antinociception to IV administration.