This prospective, experimental, randomised, assessor-blinded cadaveric study was undertaken to describe the sono-anatomical features of the radial, ulnar, median and musculocutaneous (RUMM) nerves in rabbits and to develop and evaluate an ultrasound (US)-guided proximal RUMM block technique comparing a medial versus a lateral approach. A total of 13 adult rabbit cadavers were used. In Phase I of the study, four cadavers were used for anatomical dissection and to design and test a lateral and medial single injection point US-guided proximal RUMM block technique, while in Phase II, the medial and lateral approaches were randomly performed on nine cadavers administering 0.1 mL kg−1 injectate. After dissection, nerve staining was categorised as adequate (all nerves stained ≥4 mm) or inadequate (at least one nerve not stained or stained <4 mm). Staining spread was compared with Fisher’s exact test, with p < 0.05 considered statistically significant. From Phase I, the axillary fascia containing all RUMM nerves was identified. The radial nerve exited the fascia right after the humeral head. In the lateral approach, the transducer was angled at 80° to the humerus longitudinal axis. In the medial approach, the transducer was placed perpendicularly to the humerus longitudinal axis. In both approaches, the brachial artery appeared as a rounded and anechoic structure, the musculocutaneous nerve as hypoechoic and oval and the radial nerve as a honeycomb, and the ulnar and median nerves were identified adjacent to each other. The radial nerve was selected as the injection point for both approaches using an in-plane technique. In Phase II, the injectate was found outside the axillary fascia in zero out of nine and five out of nine thoracic limbs, with an adequate staining in nine of nine and two of nine injections (p < 0.01) using the medial and lateral approach, respectively. Thus, a US-guided proximal RUMM block technique is feasible in rabbits, and the medial approach demonstrated evidence of a more consistent stain of the RUMM nerves.

OBJECTIVE:To identify worklife areas predictive of American and European Veterinary Anaesthesia Diplomate burnout. STUDY DESIGN:Cross-sectional online anonymous, voluntary survey. SAMPLE POPULATION:A total of 530 American and/or European Veterinary Anaesthesia and Analgesia College (ACVAA and ECVAA) Diplomates were canvassed, 286 responded. METHODS:Self-administered electronic questionnaire, incorporating a sociodemographic questionnaire, the Maslach Burnout Inventory-Human Service for Medical Personnel (results reported in Part 1), and the Areas of Worklife Survey (AWS). The AWS uses 28 questions to evaluate six key worklife areas in an organization. Scores ≥ 3.0 indicate better alignment between the workplace and the respondent, scores < 3.0 indicate poor alignment. Data were analysed with descriptive statistical tests and univariate and multivariate linear regression analyses (p < 0.05). RESULTS:The six AWS areas demonstrated a strong significant collective effect for the emotional exhaustion (EE) and personal accomplishment (PA) burnout domains (p < 0.001) and moderate for the depersonalization (DP) domain (p < 0.001). Workload and reward accounted for 36.6% and 17% of responders' EE scores, respectively, with EE increasing by 9.1 for each one-point rise in workload and decreasing by 7.4 for every one-point increase in feeling of reward. PA declined by 3.7 and 4.2 points, respectively, for every one-point reduction in perceived lack of fairness, and alignment with organizational values. The DP domain of burnout was influenced by the perceived lack of control, which was opposed by the sense of community, whereby for each one-point drop in level of control, DP increased by 3.0, while for each one-point gain in the sense of community, DP decreased by 3.5. CONCLUSIONS AND CLINICAL RELEVANCE:The drivers of burnout include modifiable workplace factors, many of which lend themselves to easy change. It is time for employers to consider instigating measures to reduce the risk of burnout in veterinary anaesthesia Diplomates.

OBJECTIVE:To determine the prevalence of burnout among veterinary anaesthesia specialists and explore correlations with sociodemographic variables. STUDY DESIGN:Cross-sectional, online, anonymous, voluntary survey. POPULATION:A total of 530 worldwide veterinary anaesthesia specialists affiliated to American (ACVAA) and/or European (ECVAA) Veterinary Anaesthesia and Analgesia Colleges. METHODS:An electronic questionnaire, incorporating the Maslach Burnout Inventory-Human Services Survey for Medical Personnel [MBI-HSS (MP)] and a sociodemographic questionnaire, was used. The MBI-HSS (MP) assessed the three burnout dimensions: emotional exhaustion (EE), depersonalization (DP) and personal accomplishment (PA) using 22 questions, each with a 7-point Likert-type scale answer option, to compute a total score for each dimension. Thresholds for high levels of EE ≥ 27, DP ≥ 10 and for low level of PA ≤ 33. Responders were categorized as high risk for burnout with EE ≥ 27 and DP ≥ 10, and as having burnout syndrome with EE ≥ 27, DP ≥ 10 and PA ≤ 33. Data were investigated with descriptive statistical and regression analysis; p-value < 0.05. RESULTS:Participation rate was 54% (286/530 Diplomates); 65% were identified as women; mean age was 44 years; 59% were married/civil partnership; 52% were ACVAA affiliated; 50% were working in North America; and 51% in academia. The prevalence of high risk for burnout was 42.6% (122/286), and for burnout syndrome was 24.5% (70/286). Number of hours worked per week positively correlated with EE (p < 0.0001) and DP (p = 0.02). Out-of-hours duty positively correlated with EE (p = 0.01) and DP (p = 0.04) and negatively correlated with PA (p = 0.04). Higher burnout prevalence was identified among younger Diplomates, those working ≥ 40 hours per week, in academia/research, and in North America. CONCLUSIONS AND CLINICAL RELEVANCE:Concerted effort is required to address the unacceptably high risk of developing burnout and burnout syndrome observed among ACVAA/ECVAA Diplomates.

Background: Capnography is a monitoring tool that is increasingly available in veterinary practice, providing valuable information regarding ventilatory status and tissue perfusion. While its main use is during general anaesthesia, capnography can also be applied in conscious/sedated animals.Aim of the article: This article describes how capnography works, the different devices available, and how to interpret the information provided. A discussion regarding troubleshooting is presented to help identify and solve common issues that may arise while using capnography.

Cardiac electrical activity is often altered by administration of anesthetic drugs. While the effects of propofol in this regard have previously been described in dogs, to date, there are no reports of the effect of alfaxalone. This study investigated the impact of both propofol and alfaxalone on the ECG of 60 dogs, after premedication with acepromazine and methadone. Heart rate increased significantly in both groups. The PR and QRS intervals were significantly increased following propofol while with alfaxalone the QRS duration was significantly increased and ST segment depression was observed. The QT and JT interval were significantly shorter following induction with alfaxalone, but, when corrected (c) for heart rate, QTc and JTc in both groups were significantly greater following induction. When comparing the magnitude of change between groups, the change in RR interval was greater in the alfaxalone group. The change in both QT and JT intervals were significantly greater following alfaxalone, but when QTc and JTc intervals were compared, there were no significant differences between the two drugs. The similarly increased QTc produced by both drugs may suggest comparable proarrhythmic effects.

Perioperative assessment of anesthetic risk is a valuable exercise in order to minimize complications and optimize anesthetic safety. Health status has been consistently reported to be associated with anesthetic death in humans and in the spectrum of species commonly seen in veterinary anesthesia. Hematologic and biochemical abnormalities may also be a significant consideration. Although there may be no genuine scientific or clinical background behind these types of discussion groups, they almost certainly help perpetuate the 'need' for ubiquitous preanesthetic blood testing, but given that many veterinary professionals also recommend its routine use, it obviously cannot all be dependent on owner perceptions. The recommendations for preanesthetic blood screening are restrictive in human pediatric patients. Small animal anesthesia morbidity studies have most frequently been veterinary teaching hospital based, with a few primary practice-based studies also reporting major non-fatal complications. An assessment of peri-anesthetic risk is an essential component in the process of informed owner consent.

Ultrasound-guided (US-guided) loco-regional anesthesia can provide significant analgesia and anesthetic-sparing effects when used in rabbits. The aims of this study were to investigate the thoraco-lumbar anatomy of the rabbits, particularly the quadratus lumborum (QL) muscle, to design an appropriate US-guided quadratus lumborum block (QLB) specific for rabbits, and to define the most adequate volume of injectate required to consistently cover the ventral branches of T11 to L3 without affecting the pelvic limb innervation (L4, L5 and L6). Sixteen adult rabbit cadavers were included in the study. After randomization, four different volumes of injectate (0.1 mL/kg, 0.2 mL/kg, 0.3 mL/kg and 0.4 mL/kg) were tested, with these volumes additionally randomized to two sites of injection (right or left QL fascia). An ultrasound-guided QLB was performed with a solution of lidocaine, iodinated contrast and tissue dye (in a proportion of 3:1:1 volume, respectively), with subsequent computed tomography (CT) and anatomical dissection, to evaluate the spread of the injectate. In all but one case, the US-guided QLB performed with a dorsolateral approach using 0.3 mL/kg was adequate, while a dose of 0.4 mL/kg consistently reached the targeted nerves but also extended to L4 and caudally. This may suggest that an injectate volume of 0.3 mL/kg may be the most appropriate to produce adequate spread while not affecting pelvic limb innervation.

A 4-year-old, entire, male, domestic long-haired cat was presented with an acute history of stranguria and dysuria and diagnosed with urolithiasis causing urethral obstruction. The patient was induced to general anaesthesia and several unsuccessful attempts to flush the uroliths retrogradely towards the bladder were made. An intraurethral administration of the neuromuscular blocking agent atracurium was performed as it has been reported to facilitate urethral catheterisation without any side effects. Respiratory arrest developed after 15 minutes from atracurium administration, which was promptly recognized and treated with mechanical ventilation. The absence of muscle contraction in response to a nerve stimulation confirmed a generalised muscle blockade. Approximately 35 minutes after, a muscle response to nerve stimulation appeared. Neostigmine combined with glycopyrrolate was administered resulting in complete recovery from neuromuscular blockade. In conclusion, the use of intraurethral atracurium can result in systemic absorption of the drug with subsequent generalised neuromuscular blockade.

The beneficial effects of performing regional anaesthesia techniques as part of a pre-emptive analgesic strategy are to improve perioperative analgesia and reduce opioid and general anaesthetic drug requirements. In prey species, an early recovery of voluntary motor function, especially after a regional anaesthesia, is essential for the animal health and welfare. To reduce motor paralysis, a low volume and concentration of local anaesthetic should be administered close to the targeted nerve. This is the first report of an ultrasound (14-MHz linear probe)- and nerve stimulation (0.2 mA; 0.3 second; 2 Hz)-guided saphenous and sciatic nerve blocks using bupivacaine (0.125%; 0.2 mL/kg per nerve) in a rabbit. Drug consumption, physiological response to surgery and postoperative pain scoring were used to determine block success. The ultrasound- and nerve stimulation-guided sciatic and saphenous nerve blocks could be recommended as part of multimodal pain management in rabbits undergoing appropriate pelvic limb orthopaedic surgeries.

Objective To assess the accuracy and trending capability of continuous measurement of haemoglobin concentration [Hb], haemoglobin oxygen saturation (SaO(2)) and oxygen content (CaO2) measured by the Masimo Radical-7 pulse co-oximeter in horses undergoing inhalational anaesthesia. Study design Prospective observational clinical study. Animals A group of 23 anaesthetized adult horses. Methods In 23 healthy adult horses undergoing elective surgical procedures, paired measurements of pulse cooximetry-based haemoglobin concentration (SpHb), SaO(2) (SpO(2)), and CaO2 (SpOC) and simultaneous arterial blood samples were collected at multiple time points throughout anaesthesia. The arterial samples were analysed by a laboratory co-oximeter for total haemoglobin (tHb), SaO(2) and manually calculated CaO2. Bland-Altman plots, linear regression analysis, error grid analysis, four-quadrant plot and Critchley polar plot were used to assess the accuracy and trending capability of the pulse co-oximeter. Data are presented as mean differences and 95% limits of agreement (LoA). Results In 101 data pairs analysed, the pulse co-oximeter slightly underestimated tHb (bias 0.06 g dL(-1); LoA -1.0 to 1.2 g dL(-1)), SaO(2) (bias 1.4%; LoA -2.0% to 4.8%), and CaO2 (bias 0.3 mL dL(-1); LoA -2.1 to 2.7 mL dL(-1)). Zone A of the error grid encompassed 99% of data pairs for SpHb. Perfusion index (PI) >= 1% was recorded in 58/101 and PI < 1% in 43/101. The concordance rate for consecutive changes in SpHb and tHb with PI >= 1% and < 1% was 80% and 91% with four-quadrant plot, and 45.8% and 66.6% with Critchley polar plot. Conclusions Pulse co-oximetry has acceptable accuracy for the values measured, even with low PI, whereas its trending ability requires further investigation in those horses with a higher [Hb] variation during anaesthesia.

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Ultrasound-guided (US-guided) loco-regional anesthesia techniques allow direct visualization and blockade of sensory nerves. The saphenous nerve (SN), a terminal branch of the femoral nerve (FN), is strictly a sensory nerve for which electrical locator devices are ineffective for localization as no effector muscle contractions can be evoked. US-guided SN block in species other than rabbits produces hind-limb analgesia without affecting FN motor function. The aims of this study were to develop a US-guided SN block technique in rabbits and to compare the spread obtained using two different dye volumes. Twelve hind-limbs from six cadavers (1.62 ± 0.1 kg) were included; after randomization, the SN block was performed on the right or left hind-limb, injecting 0.05 mL kg-1 or 0.1 mL kg-1 of tissue dye in lidocaine (1:50 v:v). Subsequent dissections allowed nerve staining measurements. All SNs were identified, and 17.8 ± 4.6% and 31.0 ± 8.9% of the SN length were stained using low-volume and high-volume of the dye, respectively. Regardless of the volume used, the SN was consistently stained while the motor branch of the FN was not. This US-guided technique may provide hind-limb analgesia without affecting FN motor function in rabbits undergoing mid-distal hind-limb surgeries.

Rocuronium is a non-depolarising neuromuscular block drug extensively used in canine patients due to its favourable characteristics, including the fastest onset of action among all non-depolarising neuromuscular blocking agents, lack of active metabolites and intermediate duration of effect. Although rocuronium elimination is relatively independent of kidney function, in the past few years, a growing number of reports describing a prolonged duration of the effect of rocuronium in human patients with renal failure have been published. However, to date, the mechanism behind this phenomenon is unclear. The present case describes the development of extremely prolonged neuromuscular blockade (>5 hours) following a single dose of 0.5 mg/kg rocuronium in a female English bulldog with renal disease where neostigmine failed to provide adequate reversal, which was only subsequently achieved following administration of sugammadex. Aside from renal disease, other possible causes of this prolonged duration (relative drug overdose, hypoalbuminaemia, co-administered drugs, neostigmine-induced neuromuscular blockade and idiosyncratic reaction to rocuronium) are also discussed.

Objective To compare dexmedetomidine with acepromazine for premedication combined with methadone in dogs undergoing brachycephalic obstructive airway syndrome (BOAS) surgery. Study design Randomized, blinded clinical study. Animals A group of 40 dogs weighing mean (+/- standard deviation) 10.5 +/- 6 kg, aged 2.6 +/- 1.9 years. Methods Dogs received either acepromazine 20 mu g kg(-1) (group A) or dexmedetomidine 2 mu g kg(-1) (group D) intramuscularly with methadone 0.3 mg kg(-1). Anaesthesia was induced with propofol and maintained with sevoflurane. Sedation (0-18), induction (0-6) and recovery (0-5) qualities were scored. Propofol dose, hypotension incidence, mechanical ventilation requirement, extubation time, additional sedation, oxygen supplementation, regurgitation and emergency intubation following premedication or during recovery were recorded. Data were analysed using t tests, Mann-Whitney U or Chi-square tests. Results Group A dogs were less sedated [median (range): 1.5 (0-12)] than group D [5 (1-18)] (p = 0.021) and required more propofol [3.5 (1-7) versus 2.4 (1-8) mg kg(-1); p = 0.018]. Induction scores [group A: 5 (4-5); group D 5 (3-5)] (p = 0.989), recovery scores [group A 5 (4-5); group D 5(3-5)1(p = 0.738) and anaesthesia duration [group A:93 (50-170); group D 96 (54-263) minutes] (p = 0.758) were similar between groups. Time to extubation was longer in group A 12.5 (3-35) versus group D 5.5 (0-15) minutes; (p = 0.005). During recovery, two dogs required emergency intubation (p > 0.99) and five dogs required additional sedation (p > 0.99). Oxygen supplementation was required in 16 and 12 dogs in group A and D, respectively (p = 0.167); no dogs in group A and one dog in group D regurgitated (p = 0.311). Conclusions and clinical relevance Dexmedetomidine 2 mu g kg(-1) produces more sedation but similar recovery quality to acepromazine 20 mu g kg(-1) combined with methadone in dogs undergoing BOAS surgery.

Objective To compare values of haemoglobin concentration (SpHb), arterial haemoglobin saturation (SpO(2)) and calculated arterial oxygen content (SpOC), measured non-invasively with a pulse co-oximeter before and after in vivo adjustment (via calibration of the device using a measured haemoglobin concentration) with those measured invasively using a spectrophotometric-based blood gas analyser in anaesthetized dogs. Study design Prospective observational clinical study. Animals A group of 39 adult dogs. Methods In all dogs after standard instrumentation, the dorsal metatarsal artery was catheterised for blood sampling, and a pulse co-oximeter probe was applied to the tongue for noninvasive measurements. Paired data for SpHb, SpO(2) and SpOC from the pulse co-oximeter and haemoglobin arterial oxygen saturation (SaO(2)) and arterial oxygen content (CaO2) from the blood gas analyser were obtained before and after in vivo adjustment. Bland-Altman analysis for repeated measurements was used to evaluate the bias, precision and agreement between the pulse co-oximeter and the blood gas analyser. Data are presented as mean differences and 95% limits of agreement (LoA). Results A total of 39 data pairs were obtained before in vivo adjustment. The mean invasively measured haemoglobin-SpHb difference was -2.7 g dL(-1) with LoA of -4.9 to -0.5 g dL(-1). After in vivo adjustment, 104 data pairs were obtained. The mean invasively measured haemoglobin-SpHb difference was -0.2 g dL(-1) with LoA of -1.1 to 0.6 g dL(-1). The mean SaO(2)-SpO(2) difference was 0.86% with LoA of -0.8% to 2.5% and that between CaO2-SpOC was 0.66 mL dL(-1) with LoA of -2.59 to 3.91 mL dL(-1). Conclusions Before in vivo adjustment, pulse co-oximeter derived values overestimated the spectrophotometric-based blood gas analyser haemoglobin and CaO2 values. After in vivo adjustment, the accuracy, precision and LoA markedly improved. Therefore, in vivo adjustment is recommended when using this device to monitor SpHb in anaesthetised dogs.

The development of unanticipated hyperkalaemia during general anaesthesia in healthy veterinary patients is an increasingly recognized phenomenon. Cases have been reported in dogs, cats, horses and non-domestic felids. However, recurrent hyperkalaemia has not yet been described in domestic cats. We report the development of hyperkalaemia during two consecutive anaesthetics in a 5-year-old, Bengal cat, anaesthetised for medial patella luxation repair and 3 months later for implant removal. During both procedures, hyperkalaemia was diagnosed. However, it was only during the first anaesthetic that the hyperkalaemia became life-threatening, necessitating treatment. The reasons why some animals develop hyperkalaemia during general anaesthesia are still unknown. Considering the apparent increasing frequency of this condition, hyperkalaemia should be considered as a potential cause of intraoperative bradydysrhythmias and must be investigated and treated appropriately.

OBJECTIVE:To compare noninvasive (NIBP) with invasive blood pressure (IBP) measurements from a Datex S/5 Compact monitor in anaesthetized adult dogs, and to evaluate it according to the American College of Veterinary Internal Medicine (ACVIM) and the Association for the Advancement of Medical Instrumentation (AAMI) criteria. STUDY DESIGN:Prospective clinical study. ANIMALS:A group of 34 client-owned adult dogs. METHODS:Dogs were anaesthetized for different surgical procedures using different anaesthetic protocols. IBP was measured using a catheter placed in a dorsal pedal artery. A blood pressure cuff was placed over the contralateral dorsal pedal artery for NIBP measurement. Data were recorded using the Datex iCollect program, and paired readings were matched every 3 minutes for 60 minutes. Bland-Altman and error grid analyses were used to estimate the agreement between IBP and NIBP measurements, and its clinical significance, respectively. Data were reported as mean bias [lower, upper limits of agreement (LoA)]. RESULTS:The Datex S/5 monitor conformed to most ACVIM criteria. The correlation coefficient was less than 0.9 for systolic, diastolic, and mean arterial pressures (MAP). The best agreement between the noninvasive and invasive methods was observed for MAP, with LoA (-17 to 13 mmHg) and higher percentage of NIBP readings within 5 (55.6%), 10 (81.7%) and 20 (98.6%) mmHg of the IBP values. The Datex S/5 NIBP technology did not meet the AAMI validation criteria and less than 95% of the paired measurements were found within the green zone of the error grid analysis. CONCLUSIONS AND CLINICAL RELEVANCE:The Datex S/5 monitor conformed to most ACVIM criteria but not with the more rigorous AAMI standards. Despite good agreement between IBP and NIBP for MAP measurements, care must be taken when using this device to guide therapeutic interventions of blood pressure in anaesthetized healthy adult dogs.

OBJECTIVE To determine factors associated with change in rectal temperature (RT) of dogs undergoing anesthesia. ANIMALS 507 dogs. PROCEDURES In a prospective observational study, the RT of dogs undergoing anesthesia at 5 veterinary hospitals was recorded at the time of induction of anesthesia and at the time of recovery from anesthesia (ie, at the time of extubation). Demographic data, body condition score, American Society of Anesthesiologists (ASA) physical status classification, types of procedure performed and medications administered, duration of anesthesia, and use of heat support were also recorded. Multiple regression analysis was performed to determine factors that were significantly associated with a decrease or an increase (or no change) in RT. Odds ratios were calculated for factors significantly associated with a decrease in RT. RESULTS Among the 507 dogs undergoing anesthesia, RT decreased in 89% (median decrease, −1.2°C [-2.2°F]; range, −0.1°C to −5.7°C [–0.2°F to −10.3°F]), increased in 9% (median increase, 0.65°C [1.2°F]; range, 0.1°C to 2.1°C [3.8°F]), and did not change in 2%. Factors that significantly predicted and increased the odds of a decrease in RT included lower weight, ASA classification > 2, surgery for orthopedic or neurologic disease, MRI procedures, use of an α 2 -adrenergic or μ-opioid receptor agonist, longer duration of anesthesia, and higher heat loss rate. Lack of μ-opioid receptor agonist use, shorter duration of anesthesia, and lower heat loss rate were significantly associated with an increase in RT. CONCLUSIONS AND CLINICAL RELEVANCE Multiple factors that were associated with a decrease in RT in dogs undergoing anesthesia were identified. Knowledge of these factors may help identify dogs at greater risk of developing inadvertent perianesthetic hypothermia.