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Juvenile crossbred pigs are widely used for acute and chronic animal testing due to their anatomical and physiological resemblance to humans. They are particularly prevalent in preclinical cardiovascular research, including studies investigating extracorporeal resuscitation and mechanical circulatory support devices. However, the availability of comprehensive laboratory reference values is limited. In a single-center study at the University Medical Center Freiburg, Germany, the hematologic and biochemical laboratory values of anesthetized healthy juvenile German crossbred farm pigs were determined. Blood samples were collected at the beginning of surgical procedures, either arterially or venously. Females and males were compared, and correlation with body weight was assessed. In total, 268 animals (weight 57.8 ± 12.4 kg) were included, thereof 180 castrated males (55.2 ± 7.7 kg) and 79 females (63.6 ± 18.3 kg). There were significant differences between males and females in 11 of 45 parameters and a moderate correlation between body weight and creatinine (R = 0.41, p < 0.001). The reference intervals and insights into sex and body weight correlations enhance the utility of healthy juvenile German crossbred farm pigs in translational research, providing a robust reference for future studies., (© 2024. The Author(s).)

Background: Perianesthetic death or sedation death in companion animals is an infrequent but devastating complication. Few studies have investigated the pathology associated with these deaths., Objective: To determine clinical features and postmortem findings for submissions to multiple Canadian diagnostic laboratories from perianesthetic/sedation deaths in dogs and cats., Animals and Procedure: Laboratory Information Management Systems were retrospectively reviewed for cases of perianesthetic/sedation death in dogs and cats. Inclusion criteria were: i) whole-body submissions and ii) death within 7 d after the procedure., Results: Pathology reports determined the cause of death in 43% of dogs (73/168) and 34% of cats (50/147). Spay/neuter surgeries were the most common procedure for which animals were submitted (dogs: n = 72, 31%; cats: n = 111, 58%). The American Society of Anesthesiologists physical status in these animals was low (ASA status I or II) in 94% of dogs (68/72) and 93% of cats (103/111). Clinical history was considered incomplete in 60.3% of cases (242/401)., Conclusion and Clinical Relevance: These results had similar trends to those in previous studies that identified an important proportion of submissions for perianesthetic/sedation deaths lacked significant lesions to explain the cause of death. This study also identified spay/neuter procedures were involved in the largest proportion of submissions, despite their low pre-anesthetic/sedation risk., (Copyright and/or publishing rights held by the Canadian Veterinary Medical Association.)

Background: Cardiac troponin I, a particular biomarker, is released into the bloodstream in response to myocardial injury., Objectives: To evaluate perioperative changes in high-sensitivity cardiac troponin I (hs-cTnI) concentration during ovariohysterectomy in cats undergoing three different anaesthesia protocols., Methods:  Twenty-one female mixed-breed cats owned by clients aged (2.2 ± 0.7 years) and weight (3.2 ± 0.5 kg) were included in our study. The cats were divided into three groups: propofol-isoflurane (PI) group (n = 7), xylazine-ketamine (XK) group (n = 7) and xylazine-isoflurane (XI) group (n = 7). After pre-anaesthetic propofol (6 mg/kg IV) was administered to cats in Group PI, a mask was placed, and anaesthesia was maintained with 3.0% isoflurane in oxygen. Cats in Group XK underwent general anesthetization with xylazine hydrochloride (2 mg/kg IM) and, 10 min later, ketamine hydrochloride (10 mg/kg IM). Cats in Group XI were administered xylazine hydrochloride (2 mg/kg IM), and then anaesthesia (3.0% isoflurane and oxygen) was continued with a mask. Blood samples were collected from all cats; preoperatively and postoperatively at 0 and 12 h (Pre-, Post-0 h and Post-12 h, respectively). Serum hs-cTnI concentrations were measured with the Advia Centaur TnI-Ultra., Results: In all 21 cats, hs-cTnI concentration increased at Post-0 h and 12 h measurement points compared to Pre-. In the XK group, hs-cTnI concentrations exhibited a significant increase at the Post-0 h (51.30 ng/L) and Post-12 h (157.70 ng/L) time points compared to Pre- (6.70 ng/L) (p < 0.05)., Conclusions: The XK group increased the concentration of hs-cTnI more than other protocols. In the PI group, the increase in hs-cTnI concentrations at Post-0 and 12 h increased less than the other two groups (p < 0.05). The PI group was found to induce less myocardial damage., (© None The Author(s). Veterinary Medicine and Science published by John Wiley & Sons Ltd.)

Objectives: The aim of the present study was to identify the incidence of common perioperative anaesthetic complications in cats undergoing anaesthesia for neutering in three UK first opinion practices., Methods: A retrospective anaesthetic record analysis was performed on cats anaesthetised for neutering at practices 1 and 2 between 9 December 2017 and 2 February 2021 and practice 3 between 9 March 2020 and 7 January 2021. A search of the practice management system identified all cats that had undergone neutering in the selected timeframe. Data from 1019 cats were included in the study. Information relating to patient characteristics and data from the anaesthesia session were extracted from electronic patient records and anaesthesia record charts and entered into an Excel spreadsheet. A definition of the complications was created after reviewing the literature and their incidence determined from the data set. Comparisons between different groups of cats in the study were made using a χ 2 test for homogeneity or Fisher's exact tests to identify factors associated with increased incidence of complications., Results: The anaesthetic-related mortality was 1/1019 (0.10%). The most common complications were hypotension (22.6%), bradycardia (16.7%) and hypothermia (13.8%). Less common complications were hypocapnia (12.7%), hypercapnia (8.7%), tachycardia (6.6%), apnoea (3.1%), hyperthermia (1.7%), hypertension (1.4%), endotracheal tube obstruction (1.1%), hypoxia (0.3%), undesirable recovery (0.6%) and cardiac arrhythmia (0.2%). Factors associated with increased risk of hypotension were acepromazine pre-anaesthetic medication, higher maximum isoflurane dose, longer anaesthetic duration and lower body weight. Factors associated with increased risk of bradycardia were medetomidine pre-anaesthetic medication, longer anaesthetic duration and higher body weight. Factors associated with increased risk of hypothermia were higher maximum isoflurane dose, increased anaesthetic duration and lower body weight., Conclusions and Relevance: This study showed that anaesthetic complications were frequently observed, with complications documented in 53.4% of the cats in the study. The information in this study may help to guide prioritisation of monitoring in feline anaesthesia., Competing Interests: Conflict of interestThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Objective: To assess the performance of transpulmonary thermodilution (TPTD) using room-temperature saline (CORT) and waveform-derived continuous CO (CCO) compared with TPTD using iced saline (COICED) as the indicator for measurements of CO in isoflurane-anesthetized dogs., Methods: 8 Beagles aged 1 to 2 years (7.4 to 11.2 kg) were enrolled in this experimental study from March 21 to 31, 2023. Dogs were anesthetized with 0.01 mg/kg acepromazine, 5 to 6 mg/kg propofol, and isoflurane and were mechanically ventilated. Dogs were instrumented with a central venous catheter and a femoral arterial catheter equipped with a thermistor. The COICED, CORT, and pulse wave-derived CCO values were obtained at baseline, during infusions of phenylephrine and norepinephrine, and during blood withdrawal and replacement. Data were analyzed with a mixed effect model, Bland-Altman plots, and concordance. Percent error was calculated. P < .05 was used for significance., Results: Data were collected from 8 dogs. Significant effects of time and the interaction of time and method were found. Bland-Altman plots showed negligible bias with limits of agreement between -0.35 and 0.25 L/min for CORT versus COICED and -1.23 and 1.15 L/min for CCO versus COICED. Percent errors were 17.7% and 66.6%, respectively. In the 4-quadrant plots, the concordance rate was 95% and 68% for measurements obtained with CORT and for CCO, respectively., Conclusions: Transpulmonary thermodilution using room temperature saline was accurate and able to track changes in CO. Continuous CO had a large percent error and low tracking ability., Clinical Relevance: Transpulmonary thermodilution using room temperature saline is reliable for monitoring CO and obviates the need for iced preparations in clinical scenarios.

Objective: To survey anaesthetic practices and attitudes towards veterinary patient safety in Australia., Study Design: This was a cross-sectional sample population from Australian veterinary practices, including first opinion small animal, mixed animal and referral small animal practices. The survey included practices' anaesthetic management, monitoring equipment and topics regarding patient safety., Results: Responses were obtained from 310/1700 (18%) veterinary practices, with 208 respondents from small animal practices (67%), 71 mixed animal practices (23%) and 31 referral small animal centres (10%). Overall, 61% of respondents reported always having a dedicated staff member monitoring the anaesthetic, who was most commonly a certified veterinary nurse (89%). In 22% of the practices, some of the staff monitoring an anaesthetic did not have any qualification. Completion of anaesthetic plans for each animal prior to an anaesthetic was reported by 24.5% of respondents and labelling of syringes was completed in 80% of practices. Pulse oximetry (98%) and temperature (88%) were the most common clinical variables monitored. The use of capnography (46%) or an electrocardiogram (48%) was also reported by the respondents. Emergency drugs, airway and ventilation equipment are available in 96%, 88% and 59% of practices, respectively. A defibrillator was available in 11% of practices with only 54% respondents being confident in using it. Of the respondents 60% were aware of anaesthesia safety interventions and clinical guidelines regarding patient safety during anaesthesia., Conclusions and Clinical Relevance: Despite practices showing a relative improvement over the years in the standard of anaesthesia care, most of them are still not meeting international guidelines. Areas where changes could lead to improved safety practices could include: a trained person dedicated to monitor anaesthesia, pain scoring evaluation in patients recovering from anaesthesia, an increased use of standardised handover checklists, record keeping and an increase in open discussion of adverse events by the veterinary team., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Horses are the most challenging of the common companion animals to anesthetize. Induction of anesthesia in the horse is complicated by the fact that it is accompanied by a transition from a conscious standing position to uncconconscious recumbency. The purpose of this article is to review the literature on induction of anesthesia with a focus on the behavioral and physiologic/pharmacodynamic responses and the actions and interactions of the drugs administered to induce anesthesia in the healthy adult horse with the goal of increasing consistency and predictability., Competing Interests: Declaration of competing interest None of the authors has any financial or personal relationships that could inappropriately influence or bias the content of the paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

This study evaluated the use of essential oil of Ocimum gratissimum (EOOG) for anesthesia and in transport of Colossoma macropomum. Experiment 1, Test 1, anesthesia induction and recovery times were determined using different EOOG concentrations (0, 20, 50, 100, 200, 300 mg L -1 ), with two size classes: Juveniles I (0.86 g) and Juveniles II (11.46 g) (independent tests in a completely randomized design). Based on the results of Test 1, in Test 2 Juveniles II were exposed to EOOG concentrations: 0, 20, 100 mg L -1 . Tissue samples were collected immediately after induction and 1 h post-recovery, to assess oxidative status variables. Experiment 2, Juveniles I (0.91 g) and Juveniles II (14.76 g) were submitted to transport in water with different concentrations of EOOG (0, 5, 10 mg L -1 ) (independent tests in a completely randomized design). The effects on oxidative status variables were evaluated. Concentrations between 50 and 200 mg L -1 EOOG can be indicated for Juveniles I, while concentrations between 50 and 100 mg L -1 EOOG for Juveniles II. The concentration of 100 mg L -1 EOOG was able to prevent oxidative damage in the liver. In Experiment 2, the concentrations of 5 and 10 mg L -1 EOOG added to the transport water caused sedation for both studied size classes of juveniles and did not cause oscillations in water quality variables nor any mortality. The concentration of 10 mg L -1 EOOG improved the oxidative status. It can be concluded that EOOG can be used for anesthesia and transport of C. macropomum., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

The purpose of this study was to characterize the activity of essential oils from Nepeta Cataria (EON) at concentrations of 125 μ L  L-1, 150 μ L  L-1, 175 μ L  L-1, and 200 μ L  L-1 on the behavior of loss of the posture reflex and recovery of the posture reflex and electrocardiographic activity and recording of the opercular beat of Colossoma macropomum during immersion bathing for a period of 5 min, in order to obtain a window for safe use during anesthesia. The fish (23.38 ± 3.5 g) were assigned to the following experiments: experiment 1 (latency to loss and recovery of the posture reflex): (a) 125 μ L  L-1, (b) 150 μ L  L-1, (c) 175 μ L  L-1, and (d) 200 μ L  L-1 (n = 9) per group. Experiment 2 (electrocardiographic and heartbeat recordings): (a) control group; (b) vehicle control group (2 ml of alcohol per liter of water), (c) 125 μ L  L-1, (d) 150 μ L  L-1, (e) 175 μ L  L-1, and (f) 200 μ L  L-1 (n = 9), per group. All the concentrations used showed efficacy in inducing loss of the posture reflex and reversibility with recovery of the posture reflex, but the electrocardiographic recordings indicated morphographic changes such as bradycardia during induction and p wave apiculation during recovery at the highest concentrations tested. In this way, we suggest a safe use window for short-term anesthesia with EON in the concentration range of 125 to 150 μ L  L-1 for juvenile Colossoma macropomum., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Objective: To establish an echocardiographic technique in koi carp (Cyprinus carpio), compare cardiopulmonary parameters under manual restraint versus anesthesia, and provide a gross anatomical and histologic cardiac description., Methods: A randomized, crossover echocardiography study was performed in 40 clinically healthy adult, unknown sex, privately owned koi carp on May 10 and 11 through June 26 and 27, 2021. Echocardiography was examined for each koi under manual restraint and isoeugenol at 50 ppm, with 3 measurements per examination performed by a radiologist and cardiologist. Two koi were euthanized for gross anatomic and histologic cardiac evaluation., Results: Mean ejection fraction (EF), stroke volume (SV), and cardiac output (CO) were significantly lower, mean heart rate (HR) was significantly higher, and opercular rate (OPR) was decreased significantly in anesthetized compared to manually restrained koi. Poor reproducibility for EF and SV was observed., Conclusions: Echocardiography was feasible in both manually restrained and anesthetized koi; however, this technique may best be applied to monitoring trends over time in individual fish due to low reproducibility. Significant differences in multiple cardiopulmonary parameters, including HR, EF, SV, CO, and OPR, were present between manually restrained and anesthetized koi. A gross anatomic and histologic cardiac description is provided for this species to pair with the echocardiographic images., Clinical Relevance: This study provides the first description of echocardiography, cardiac gross anatomy, and histology in koi. The results support echocardiography as a safe and practical noninvasive diagnostic for cardiac assessment in koi under both manual restraint and anesthesia.

Background: Patient safety is essential in small animal anaesthesia. This study aimed to assess anaesthesia-related deaths in cats worldwide, identify risk and protective factors and provide insights for clinical practice., Methods: A prospective multicentre cohort study of 14,962 cats from 198 veterinary centres across different countries was conducted. Data on anaesthesia-related deaths, from premedication up to 48 hours postextubation, were collected. Logistic regression was used to analyse patient demographics, American Society of Anesthesiologists (ASA) classification, procedure type and anaesthetic drugs., Results: The anaesthesia-related mortality was 0.63%, with 74.5% of deaths occurring postoperatively. Cats with cachexia, a higher ASA status or who underwent abdominal, orthopaedic/neurosurgical or thoracic procedures exhibited elevated mortality. Mechanical ventilation use was associated with increased mortality. Mortality odds were reduced by the use of alpha 2 -agonist sedatives, pure opioids in premedication and locoregional techniques., Limitations: Limitations include non-randomised sampling, potential biases, unquantified response rates, subjective death cause classification and limited variable analysis., Conclusions: Anaesthetic mortality in cats is significant, predominantly postoperative. Risk factors include cachexia, higher ASA status, specific procedures and mechanical ventilation. Protective factors include alpha 2 -agonist sedatives, pure opioids and locoregional techniques. These findings can help improve anaesthesia safety and outcomes. However, further research is required to improve protocols, enhance data quality and minimise risks., (© 2024 The Authors. Veterinary Record published by John Wiley & Sons Ltd on behalf of British Veterinary Association.)

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., (© 2023 The Authors. Veterinary Record published by John Wiley & Sons Ltd on behalf of British Veterinary Association.)

Heart rate measurements can be useful for the monitoring of both physical and mental condition in humans and nonhuman animals. Yet, information about heart rates in chimpanzees, who are phylogenetically the closest species to humans, is scarce. Existing data on chimpanzee heart rates have mainly been collected from chimpanzees under anesthesia. To address this issue, we conducted electrocardiogram recordings in captive chimpanzees under normal conditions without anesthesia based on positive reinforcement training. We obtained a total of 771 recordings from 35 individuals (22 males and 13 females, 14-53 years old) with no cardiac problems. The females had a higher heart rate than the male chimpanzees, and heart rate decreased as a function of age. In addition, heart rate was lower in the morning and increased during the day. Overall, the mean heart rate of adult males was 86.5 beats/min, and that of female chimpanzees 106.4 beats/min. Our data could serve as a reference point for future research and health-based monitoring of chimpanzee heart rates., (© 2024. The Author(s), under exclusive licence to Japan Monkey Centre.)

The study objective was to assess acceptability, feasibility, likeability, and applicability of interactive virtual reality with feedback loops (VR) to teach and assess veterinary anesthesia machine operation. Data from 60 students were analyzed. Students learned and trained how to use the anesthesia machine components and connections and performed safety checks (such as the pressure check) using real and VR machines. Competency was assessed with oral/practical and VR exams. A questionnaire survey gathered student affective skill perception toward VR for education. Students perceived VR for veterinary education as positive, useful, likeable, and helpful to learn the anesthesia machine. VR appeared to increase cognitive load, inducing lower VR exam scores of 100 (92.4-97.9) when compared to oral/practical exams of 100 (98-99.8) with p = .018. Training times with either real or VR anesthesia machines were similar ( p = .71). A positive correlation was found between VR training times and VR exam scores (Spearman's correlation coefficient 0.5; p < .001). No correlations were identified between oral/practical exam scores and training times. Seventy two percent of the students ( n = 43) had never used VR before. Prior VR experience was not necessary to train using VR. Computer glitches and cybersickness are important drawbacks to consider when using VR for education. The study demonstrated that interactive, immersive VR received favorable reactions from students. The VR incorporated educational feedback loops can be utilized as a simulation trainer for veterinary education. However, inherent limitations should be considered.

This study evaluated the anesthetic and sedative effects of the essential oil of Zingiber officinale (EOZO) on juvenile pacu (Piaractus mesopotamicus). Experiment 1 evaluated concentrations of 0, 50, 100, 200 and 400 mg L -1 EOZO for times of induction and recovery from anesthesia. Furthermore, hematological responses and residual components of EOZO in plasma were determined immediately after anesthesia. Experiment 2 evaluated the effect of 0, 10, 20 and 30 mg L -1 EOZO on water quality, blood variables and residual components of EOZO in plasma and tissues (muscle and liver) immediately after 2 h of transport. Survival was 100%. The three main compounds of EOZO [zingiberene (32.27%), β-sesquiphellandrene (18.42%) and β-bisabolene (13.93%)] were observed in animal plasma and tissues (muscle and liver) after anesthesia and transport, demonstrating a direct linear effect among the evaluated concentrations. The concentration of 200 mg L -1 EOZO promoted surgical anesthesia of pacu and prevented an increase in monocyte and neutrophil levels, yet did not alter other hematological parameters. The use of 30 mg L -1 EOZO has a sedative effect on juvenile pacu, thereby reducing oxygen consumption during transport. Furthermore, the use of 30 mg L -1 EOZO in transport water prevented an increase in hemoglobin and hematocrit, with minimal influences on other blood variables., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Arterial blood pressure (ABP) is often measured with oscillometry during anaesthesia. Changing the height of the measuring cuff with respect to the level of the heart is known to affect oscillometry accuracy in some species; however, this effect has not been investigated in cats. The objective of this study was to determine the effects of raising and lowering the measuring cuff from standard position (level of the heart) on ABP, measured with PetMAP, in anaesthetised cats. ABP readings were obtained from 29 cats with the cuff at standard position (baseline), and 5 cm above and below the heart. The end-tidal isoflurane concentrations were maintained constant during data acquisition. There were no differences between baseline values and those measured below the heart, while ABP measured above the heart was consistently lower than baseline for both the thoracic and pelvic limbs (P < 0.001), with absolute differences of 8.2 (2.5 - 14) mmHg and 6.5 (3.0 - 15.0) mmHg, respectively. Systolic ABP readings at the pelvic limb were consistently higher than those at the thoracic limb at standard position (112 ± 26 versus 103 ± 21 mmHg, p = 0.010), above (106 ± 22 versus 95 ± 20 mmHg, p = 0.003), and below the heart (116 ± 26 versus 107 ± 22 mmHg, p = 0.011). This study shows that raising the cuff by 5 cm above the heart, which may become necessary during procedural positioning, results in clinically significant underestimation of ABP measured with PetMAP., Competing Interests: Declaration of Competing Interest None of the authors has any financial or personal relationships that could inappropriately influence or bias the content of the paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Black-handed spider monkeys ( Ateles geoffroyi ssp.) are endangered in Mexico. Safe anesthetic protocols are important for in situ and ex situ conservation problems. Such protocols are scarce in the literature; nor have safety and physiologic responses been reported. High doses and volume are a counter side for field immobilizations. We tested an anesthetic protocol with a combination of tiletamine-zolazepam (5 mg/kg) plus xylazine (1 mg/kg) in 14 black-handed spider monkeys under human care from two facilities in Mexico. Physiological parameters such as HR, RR, T, SPO 2 , systolic arterial pressure (), diastolic arterial pressure (DAP), and median arterial pressure (MAP) were obtained. HR and RR decreased over time, but T increased significantly during the anesthetic time for the whole group; RR and T decreased for juveniles only. Variation between individuals was observed for HR, RR, and DAP. Volume reduction of drugs was achieved compared to previously reported anesthesia protocols. Induction time was fast (6.2 ± 10.4 min) and no tail prehension was seen. Recovery was prolonged (mean and SD). Physiologic parameters remained stable throughout. The protocol proved to be safe for the chemical immobilization of black-handed spider monkeys.

Pulse oximetry (SpO 2 ) identifies a decrease in the partial pressure of oxygen (PaO 2 ) when it falls below 80 mmHg, while oxygen reserve index (ORi), a dimensionless index ranging from 0 to 1, detects PaO 2 changes between 100 and 200 mmHg. This study investigates the usefulness of ORi in detecting impending deoxygenation before traditional SpO 2 . Fifty-one dogs undergoing anesthesia were mechanically ventilated maintaining a fraction of inspired oxygen of 0.50 and an ORi of 1. Animals were classified according to their body condition score (BCS) as normal-fit (BCS 4-5/9), overweight (BCS 6-7/9), or obese (BCS 8-9/9). At the end of the procedure, dogs were placed in sternal recumbency, and after 10 min disconnected from the ventilator and maintained in apnea. ORi added warning time was determined at various ORi values as the time difference in reaching SpO 2 of 95% from ORi of 0.9 and 0.5, compared to the SpO 2 warning time from SpO 2 of 98%. During apnea, ORi decreased before noticeable SpO 2 changes. An ORi of 0.9 anticipated an SpO 2 of 95% in normal-fit dogs by 87 (33-212) [median (range)] seconds or in those with a BCS ≥ 6/9 by 49 (7-161) seconds. Regardless of the BCS class, the median time from ORi of 0.5 to SpO 2 of 95% was 30-35 s. ORi declined from 0.9 to 0.0 in 68 compared to 33 s between normal-fit and obese dogs (p < 0.05). In dogs, ORi added warning time could facilitate timely intervention, particularly in obese patients., Competing Interests: Declaration of competing interest This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. None of the authors has any financial or personal relationships that could inappropriately influence or bias the content of the paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Objective: To provide an overview of medication errors (MEs) in veterinary medicine, with a focus on the perianesthetic period; to compare MEs in veterinary medicine with human anesthesia practice, and to describe factors contributing to the risk of MEs and strategies for error reduction., Databases Used: PubMed and CAB abstracts; search terms: [("patient safety" or "medication error∗") AND veterin∗]., Conclusions: Human anesthesia is recognized as having a relatively high risk of MEs. In veterinary medicine, MEs were among the most commonly reported medical error. Predisposing factors for MEs in human and veterinary anesthesia include general (e.g. distraction, fatigue, workload, supervision) and specific factors (e.g. requirement for dose calculations when dosing for body mass, using several medications within a short time period and preparing syringes ahead of time). Data on MEs are most commonly collected in self-reporting systems, which very likely underestimate the true incidence, a problem acknowledged in human medicine. Case reports have described a variety of MEs in the perianesthetic period, including prescription, preparation and administration errors. Dogs and cats were the most frequently reported species, with MEs in cats more commonly associated with harmful outcomes compared with dogs. In addition to education and raising awareness, other strategies described for reducing the risk of MEs include behavioral, communication, identification, organizational, engineering and cognitive aids., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Heat supplementation during surgery is a common practice; however, thermal support is not commonly used during anesthesia induction. Mice lose body temperature quickly, and air movement can exacerbate this, potentially putting mice at a thermal deficit before surgery. Whether the method of warming during induction affects overall heat loss during anesthesia is unknown. We hypothesized that the method of heating would affect body temperature (Tb) during anesthesia induction, maintenance, recovery, and once placed back on the rack. Mice (C57BL/6NHsd-6M/6F [C57BL/6]; Hsd:Athymic Nude-Foxn1nu [Nude]; N = 24;12M/12F) were assigned to a treatment in a factorial design: thermal chamber (TC; ambient temperature [Ta] = 28.8°C); heating pad (HP; induction chamber placed on an electric heating pad;Ta = 28.4°C); and control (Ctrl; Ta = 21.6°C). During induction, one mouse at a time was anesthetized with isoflurane over a 3min period and then maintained under anesthesia for 10min on a hot water heating pad (33 °C). Then isoflurane was stopped and time to ambulation was recorded. Tb and activity were tracked in the home cage on the rack before and after anesthesia. During induction, Ctrl mice lost significantly more heat (-2.8 °C) than did TC (+0.2 °C) and HP mice (+0.1 °C) but TC and HP were not different. During anesthesia maintenance, Ctrl mice regained 1 °C, but their Tb was still lower than that of the treated groups. Nude mice consistently had a lower Tb than C57BL/6 mice, regardless of treatment or anesthesia phase. C57BL/6 Ctrl mice took longer to ambulate than either HP or TC mice, but the method of heating did not differentially affect Nude mice. In general, C57BL/6 as compared with Nude and females as compared with males were comparatively more active and had higher Tb during certain times of day, regardless of the heating methods. Overall, our findings support the provision of heat during anesthesia induction, regardless of method, to reduce overall Tb loss during a short anesthesia event.

Volatile anesthetic agents are potent greenhouse gases with warming potential hundreds to thousands of times greater than CO2. As health systems, both human and veterinary, seek to reduce their environmental impacts, responsible anesthetic stewardship is a topic of great interest. Through an online survey, we explored the levels of awareness, beliefs, interest, needs, and current actions of veterinary anesthesia professionals around the climate impacts of anesthetic care. We found that even within a respondent group with specialized training and experience, there were significant knowledge gaps about anesthesia's environmental impacts. We also found there is much interest in learning more about climate-friendly anesthesia and broader sustainability initiatives for the veterinary profession. Fortunately, there already exist many ways for the profession to reduce our environmental impact while still providing excellent patient care. In this article, we explore 5 broad categories of action: (1) reducing the overall quantity of anesthetic agent used; (2) choosing lower-impact anesthetics; (3) considering the fate of the anesthetic end product; (4) expanding learning through formal education, experience, and research; and (5) reaching beyond anesthesia to implement a range of sustainability initiatives at veterinary workplaces. Together, we have an opportunity to create a healthier future for our world, our patients, and each other.

Plethysmography is employed in nonhuman primates (NHPs) to calculate respiratory minute volume and determine the exposure time required to deliver an aerosol at the target dose. Anesthetic drugs can impact breathing parameters like steady-state minute volume (SSMV) central to aerosol dosing. Alfaxalone-midazolam mixtures (AM) provide superior parameters for plethysmography in cynomolgus macaques. An obstacle to the use of AM is the volume required to anesthetize via intramuscular injection. A more concentrated formulation of alfaxalone will reduce injection volumes and refine AM protocols. The purpose of this study was to compare AM using the Indexed 10-mg/mL (AM10) formulation compared with an investigational 40-mg/mL (AM40) formulation for IM administration in cynomolgus macaques undergoing plethysmography. We hypothesized that AM10 and AM40 would show no difference in quality of anesthesia (QA), duration of anesthesia, SSMV, accumulated minute volume (AMV), and side effects. We also hypothesized that female macaques would have a longer duration of anesthesia compared with males using both formulations. The study used 15 cynomolgus macaques comprised of 8 females and 7 males. NHPs were compared between 2 separate and randomized anesthetic events no less than one week apart. Each animal served as its own control and animals were randomized by random number generation. Anesthetized NHPs were placed in a sealed plethysmography chamber, and minute volume measurements were calculated every 10 s to determine SSMV. Once SSMV was achieved for 20 min, the trial ended. There were no statistically significant differences between AM10 and AM40 for duration of anesthesia, SSMV, AMV, side effects, or QA. AM40 had a significantly smaller injection volume. Females did not show a significantly longer median duration of anesthesia using either of the alfaxalone formulations. Overall, AM40 offers a more humane anesthetic than AM10 for plethysmography in cynomolgus macaques.

Objective: This study aimed to compare the sedative effects of dexmedetomidine administered to dogs subcutaneously (SC) at the Governing Vessel 20 (GV20) acupuncture point and at another point on the head., Animals and Procedure: Ten client-owned dogs were included. Dogs were sedated 2 times, 14 d apart, with 200 μg/m 2 of dexmedetomidine, SC, at GV20 and at a point at the base of the ear (SC-head). The sedation was assessed with a sedation scale and a Dynamic and Interactive Visual Analogue Scale (DIVAS). The ease of performing radiographic studies, physiological parameters, and adverse events were recorded. Statistical linear mixed-effect models (ANOVA) were applied. Statistical significance was set at P < 0.05., Results: The time to sedation and sedation scores were similar for both groups. The level of sedation achieved was adequate to perform orthopedic radiographs for 9/10 (90%) cases in the GV20 group and 8/10 (80%) cases in the SC-head group. Heart and respiratory rates decreased significantly over time in both groups ( P < 0.001). Adverse events were infrequent and self-limiting., Conclusion: Our study provides evidence that SC administration of dexmedetomidine on the head, at the GV20 point or at the base of the ear, is easy and provides a sufficient level of sedation to obtain orthopedic radiographs in dogs., (Copyright and/or publishing rights held by the Canadian Veterinary Medical Association.)

Nile tilapia, Oreochromis niloticus, is the most cultivated fish species in the world, due to its low cost, high growth rate, environmental adaptability, and resistance to disease and stress. Anesthetics for fish become necessary in management because they minimize mortality during transport and maintenance of ponds, one of the most used anesthetics is clove oil, which has eugenol as the major substance, representing 90-95 % of clove oil. The present study evaluates the effect of eugenol on cardiac activity in Oreochromis niloticus specimens and relates it to behavioral data to determine a concentration window for safe anesthesia. For the comportamental analysis, was used five treatments (50, 75, 100, 125, and 150 μL·L -1 ) were evaluated and for the eletrocardiographic test was used seven groups (Control, Vehicle, 50, 75, 100, 125, and 150 μL·L -1 ), n = 9/treatment, totaling 108 animals. Behavioral and electrocardiographic tests were performed on all treatments during induction and recovery. The results of the behavioral tests demonstrated the reversibility of the effects with recovery of the posture reflex, varying according to the concentration. The ECG results showed a slow recovery because, at concentrations above 100 μL·L -1 , there was no full reversibility of the cardiac effects in the observed experiment time, which could cause greater changes in the tilapia hemodynamics, which led us to identify a window for safe anesthesia. Eugenol is an effective anesthetic in Nile tilapia juveniles when used in concentrations ranging from 50 to 100 μL·L -1 , if there is a need for anesthetic deepening, doses above 100 μL·L -1 , however, the animals must be monitored due to hemodynamic changes., Competing Interests: Declaration of competing interest The authors declare no following financial interests/personal relationships which may be considered as potential competing interests., (Copyright © 2024. Published by Elsevier Inc.)

The purpose of this study was to assess sedation, emesis and cardiovascular effects of dexmedetomidine alone or combined with acepromazine in healthy cats. Fourteen male cats aged 0.9 ± 0.5 years and weighing 3.7 ± 0.7 kg were randomly assigned to one of two experimental groups: GD, dexmedetomidine 5 µg/kg; and GDA, dexmedetomidine 5 µg/kg with acepromazine 0.03 mg/kg, all intramuscularly. Measurements were recorded at baseline, at 20 minutes and then at 10-minute intervals following sedation and included heart rate (HR), respiratory rate (F R ), systolic arterial pressure (SAP), rectal temperature (RT), number of episodes of emesis and sedation score (0-4). Data were compared using ANOVA for repeated measures followed by Šídák and Dunnet test. Sedation scores were compared between groups at T20 using Mann-Whitney test. Significance was considered when P <0.05. At T20, HR was significantly lower in GDA (99 ± 14 beats/min) compared with GD (133 ± 19 beats/min) and SAP was significantly lower in both groups compared with baseline (126 ± 14 vs. 148 ± 26 and 111 ± 13 vs. 144 ± 17 mmHg in GD and GDA, respectively). Duration of sedation was similar between groups, although sedation scores differed significantly at T20, with 1 (0-4) in GD and 4 (4-4) in GDA. More episodes of emesis were recorded in GD compared with GDA. The combination of dexmedetomidine and acepromazine produced more profound sedation with faster onset and lower incidence of emesis compared with dexmedetomidine alone in healthy cats., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Objective: To compare the accuracy of doppler ultrasound (DOP) and pulse oximeter plethysmography (POP) in the measurement of systolic arterial pressure (SAP) to invasive blood pressure (IBP) in anesthetized dogs., Animals: 40 client-owned healthy dogs > 10 kg., Methods: Dogs were anesthetized for surgical procedures in dorsal recumbency. Invasive blood pressure was measured from a dorsal pedal artery. DOP and POP device probes were placed over the median caudal artery with a flow-occluding cuff for noninvasive blood pressure measurement. Systolic arterial pressure measured by DOP, loss of pulse oximeter plethysmograph (POPL), and return of pulse oximeter plethysmograph (POPR) were compared to SAP measured by IBP. A linear mixed model was used to determine correlation. Bland-Altman analyses were performed to determine bias, SD, and limits of agreement. The accuracy of DOP and POP was compared to IBP across different tensive states., Results: Conditional R2 values for DOP, POPL, and POPR versus IBP were 0.92, 0.85, and 0.87, respectively (all P < .001). The biases for DOP, POPL, and POPR compared to IBP were +7.6 ± 13.1, +3.9 ± 14.4, and +8.6 ± 15.2 mm Hg (bias ± SD), respectively. Limits of agreement (lower, upper) were (-18.1, +33.3), (-24.3, +32.1), and (-21.2, +38.4) mm Hg for DOP, POPL, and POPR, respectively. DOP and POP overestimated SAP during hypotension (SAP < 90 mm Hg), DOP to a lesser magnitude., Clinical Relevance: DOP measured from the median caudal artery may be acceptable for SAP measurement in dorsally recumbent, healthy anesthetized dogs > 10 kg. POP was determined an unacceptable method.

A growing spotlight on insect welfare as research subjects, fodder for vertebrate animals, and patients for veterinarians highlights the need to establish humane euthanasia methods for these species. An insect of increasing commercial importance is the king worm (Zophobas morio), a type of darkling beetle larvae. The initial objective of this study was to determine if prolonged exposure to isoflurane would lengthen anesthetic recovery and lead to euthanasia. Larvae were exposed to isoflurane for 10 min, 40 min, 70 min, 190 min, 13 h, and 24 h (n = 10 for each treatment duration group), and time to recovery was subsequently monitored in room air. The second objective was to determine effectiveness of secondary euthanasia methods: injectable potassium chloride at 1 mg/g body weight (n = 5) and 3 mg/g body weight (n = 5) doses; immersion in 200 proof ethanol (n = 10), 10% buffered formalin (n = 10), and water (n = 10); and freezing at -18°C (n = 10). Prolonged exposure to isoflurane led to extended recovery times, but 100% mortality was not achieved. Submersion in ethanol and injection of potassium chloride at a 3 mg/g body weight dose resulted in 100% mortality. If these larvae are to be used as future food sources, a humane euthanasia method that preserves the ability to be consumed is required., (© 2024 Wiley Periodicals LLC.)

Objective: To report the effects of alfaxalone and dexmedetomidine based sedation protocols on echocardiographic and hemodynamic variables in cats with hypertrophic cardiomyopathy (HCM) during sedation and inhalational anesthesia., Study Design: Prospective, randomized, experimental study., Animals: A group of 10 client-owned cats with subclinical HCM., Methods: Cats were administered one of two sedative intramuscular combinations: protocol ABM (alfaxalone 2 mg kg -1 , butorphanol 0.4 mg kg -1 , midazolam 0.2 mg kg -1 ; n = 5) or protocol DBM (dexmedetomidine 8 μg kg -1 , butorphanol 0.4 mg kg -1 , midazolam 0.2 mg kg -1 ; n = 5). General anesthesia was induced with intravenous alfaxalone and maintained with isoflurane in oxygen. Echocardiographic variables and noninvasive arterial blood pressures were obtained before sedation, following sedation, and during inhalational anesthesia. Sedation scores and alfaxalone induction dose requirements were recorded. Descriptive statistics are reported for cardiovascular variables., Results: During sedation, echocardiographic and hemodynamic variables remained within normal limits with protocol ABM, whereas protocol DBM was characterized by bradycardia, low cardiac index and elevated blood pressure. During isoflurane anesthesia, both protocols demonstrated similar hemodynamic performance, with heart rates of 98 ± 12 and 89 ± 11 beats min -1 , cardiac index values of 68 ± 17 and 47 ± 13 mL min -1 kg -1 and Doppler blood pressures of 72 ± 15 and 79 ± 20 mmHg with protocols ABM and DBM, respectively. A reduction in myocardial velocities were also observed during atrial and ventricular contraction with both protocols during isoflurane anesthesia., Conclusions and Clinical Relevance: An alfaxalone based protocol offered hemodynamic stability during sedation in cats with HCM; however, both dexmedetomidine and alfaxalone based protocols resulted in clinically relevant hemodynamic compromise during isoflurane anesthesia. Further studies are required to determine optimal sedative and anesthetic protocols in cats with HCM., (Published by Elsevier Ltd.)

Guinea pigs are often used in translational research, but providing them with safe and effective anesthesia is a challenge. Common methods like inhalant anesthesia and injectable ketamine/xylazine induce surgical anesthesia but can negatively affect cardiovascular, respiratory, and thermoregulatory systems and complicate the interpretation of research outcomes. Several alternative anesthetic regimens have been investigated, but none have consistently achieved a surgical plane of anesthesia. Therefore, identifying an anesthetic regimen that achieves a stable state of the surgical plane of anesthesia while preserving cardiorespiratory function would be a valuable contribution. To address this issue, we compared the efficacy of 3 anesthetic combinations in female Dunkin-Hartley guinea pigs: 1) alfaxalone, dexmedetomidine, and fentanyl (ADF); 2) alfaxalone, midazolam, and fentanyl (AMF); and 3) alfaxalone, midazolam, fentanyl, and isoflurane (AMFIso). We monitored anesthetic depth, heart rate, oxygenation, respiratory rate, respiratory effort, blood pressure, and body temperature every 15 min from injection to recovery. We also recorded the time to loss of righting reflex, duration of anesthesia, and time to achieve a surgical plane. The results showed no statistically significant differences in induction and recovery times among the groups. In the AMFIso group, 100% of the animals achieved a surgical plane of anesthesia, whereas only 10% of the animals in the AMF group reached that level. None of the animals in ADF group reached a surgical plane of anesthesia. Respiratory rate was significantly lower in the AMFIso as compared with the ADF group ( P < 0.001) but was not different between the AMF and ADF groups. Temperature was significantly lower in the AMFIso group as compared with both the ADF and AMF groups ( P < 0.001). In conclusion, both combinations of solely injectable anesthetics assessed in this study can be used for short, nonpainful procedures without significant cardiorespiratory depression. However, for mildly to moderately painful surgical procedures, the addition of an inhalant anesthetic like isoflurane is necessary for female guinea pigs.

The effects of commonly used injectable combinations of anesthetics such as ketamine and xylazine, with or without acepromazine, vary widely across individuals, have a shallow-dose response curve, and do not provide long-term analgesia. These drawbacks indicate the importance of continuing efforts to develop safe and effective injectable anesthetic combinations for mice. In this study, a series of experiments was designed to validate the use of dexmedetomidine and midazolam to provide chemical restraint for nonpainful procedures and the addition of buprenorphine or extended-release buprenorphine to reliably provide a surgical plane of anesthesia in C57BL/6J mice. Loss of consciousness was defined as the loss of the righting reflex (LORR); a surgical plane of anesthesia was defined as the LORR and loss of pedal withdrawal after application of a 300 g noxious stimulus to a hind paw. The combination of intraperitoneal 0.25 mg/kg dexmedetomidine and 6 mg/kg midazolam produced LORR, sufficient for nonpainful or noninvasive procedures, without achieving a surgical plane in 19 of 20 mice tested. With the addition of subcutaneous 0.1 mg/kg buprenorphine or 1 mg/kg buprenorphine-ER, 29 of 30 mice achieved a surgical plane of anesthesia. The safety and efficacy of the regimen was then tested by successfully performing a laparotomy in 6 mice. No deaths occurred in any trial, and, when administered 1 mg/kg atipamezole IP, all mice recovered their righting reflex within 11 min. The anesthetic regimen developed in this study is safe, is reversible, and includes analgesics that previous studies have shown provide analgesia beyond the immediate postsurgical period. Buprenorphine-ER can be safely substituted for buprenorphine for longer-lasting analgesia.

The Houston toad ( Anaxyrus houstonensis ), a primarily terrestrial amphibian of south-central Texas, has been listed as federally endangered since 1970. Sedation is an important tool for obtaining diagnostics and providing treatment in this species. This prospective, randomized, and blinded study compared the sedative effects of SC alfaxalone (Protocol A) at approximately 12 mg/kg (median [range] = 12.70 [12.09-13.95] mg/kg] to SC alfaxalone-dexmedetomidine (Protocol AD) at approximately 12 mg/kg (median [range] = 12.68 [12.16-13.56] mg/kg) and 0.1 mg/kg (median [range] = 0.1 [0.07-0.13] mg/kg), respectively, in adult Houston toads ( n = 26). Toads from Protocol AD received atipamezole SC at approximately 1 mg/kg (median [range] = 0.96 [0.75-1.25] mg/kg) 45 min postinduction, whereas toads from Protocol A received the equivalent volume of SC sterile saline at the same time point. Heart rate, gular rate, and times to first effect, loss of righting reflex, ability to position for radiographs, loss of nociception, return of righting reflex, and full recovery were recorded. A significantly greater number of toads lost righting reflex, positioned for radiographs, and lost nociception with Protocol AD compared with Protocol A. Additionally, time to return of righting reflex and time to full recovery were significantly longer with Protocol AD than with Protocol A. The protocols did not differ significantly in time to first effect, time to radiographic positioning, or time to loss of nociception. Histologic examination of four toads euthanized during the study revealed acute injection site reactions from all administered drugs, including saline. No clinical adverse reactions were observed. This study demonstrates that the combination of SC alfaxalone and dexmedetomidine results in deeper sedation than SC alfaxalone alone, but also correlates with longer recovery times despite antagonist administration.

Objective: The aim of this study was to describe the onset and duration of action of escalating doses of atracurium in healthy, anesthetized goats., Study Design: Randomized, blinded, triple crossover study. Animals A total of eight (five males and three females) healthy goats weighing 42.7-123.5 kg and aged from 11 months to 8 years., Methods: Goats were anesthetized three times with propofol and anesthesia was maintained with isoflurane. One of three doses of atracurium was administered intravenously 30 minutes after induction: 0.25 mg kg -1 (AT25), 0.5 mg kg -1 (AT50) or 0.75 mg kg -1 (AT75). Acceleromyographic train-of-four ratio (TOFR) followed by train-of-four counts (TOFC) were recorded at 30 second intervals after atracurium administration to determine blockade onset (TOFC = 0). The TOFR followed by TOFC were recorded at 5 minute intervals until return to pre-atracurium baseline (TOFR = 1.0). Normally distributed data were analyzed with repeated measures anova and a Tukey multiple comparison test. Data not normally distributed were analyzed with a Friedman test and a Dunn's multiple comparison test., Results: For AT50 and AT75, 100% of goats achieved TOFC = 0 after atracurium administration. For AT25, however, 87.5% of goats achieved TOFC = 0 after atracurium administration. The onset time was shorter for AT75 [1.5 (0.5-1.5) minutes; median (range)] than for AT25 [2 (1-4) minutes] (p = 0.048). The duration of action [from onset time to complete reversal (TOFR = 1.0)] was significantly shorter for AT25 (52 ± 12 minutes, mean ± SD) than for AT50 (77 ± 18 minutes) (p < 0.001) and AT75 (85 ± 16 minutes) (p < 0.001). There was no significant difference in duration between AT50 and AT75 (p = 0.238)., Conclusions and Clinical Relevance: Doses of 0.5 and 0.75 mg kg -1 atracurium may produce complete neuromuscular blockade in healthy, anesthetized goats., (Copyright © 2023 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia. Published by Elsevier Ltd. All rights reserved.)

This retrospective study aimed to assess the incidence of hypotension and the subsequent administration of dobutamine in horses anesthetized with isoflurane and romifidine during elective surgery. Time from induction of anaesthesia to administration of dobutamine was registered, as well as the time and dose needed to restore mean arterial pressure (MAP) ≥ 70 mmHg. Additionally, the influence of patient and anaesthesia related parameters on the need for dobutamine supplementation was evaluated. In total, 118 horses were included in this retrospective study. Dobutamine was administered to effect when MAP<70 mmHg. Data registered: patient weight, acepromazine premedication, body position, administration of intraoperative ketamine bolus, locoregional anaesthesia, mechanical ventilation, duration of anaesthesia, dose and duration of dobutamine administration, heart rate, MAP before dobutamine administration, MAP and time required to increase MAP≥70 mmHg. Dobutamine infusion was needed in 54.2% of the horses 30 ± 17 min after isoflurane-romifidine anaesthesia started. Dobutamine 0.55 ± 0.18 μg kg -1  min -1 achieved a MAP≥70 mmHg in 12 ± 8 min. Duration of dobutamine infusion was 56 ± 37 min. An univariable logistic regression showed a significant association between dobutamine and acepromazine administration (p = 0.01; OR = 3.43), anaesthesia time (p = 0.02; OR = 2.41) and dorsal recumbency (p < 0.001; OR = 8.40). In a multivariable logistic regression, only dorsal recumbency significantly increased the need for dobutamine supplementation (p < 0.001; OR = 7.70). There was no significant association between patient weight (p = 0.11; OR = 1), locoregional anaesthesia (p = 0.07; OR = 0.47), administration of a ketamine bolus (p = 0.95; OR = 0.98) or volume controlled ventilation (p = 0.94; OR = 1.04) and dobutamine administration. Low doses of dobutamine were suitable to restore MAP above 70 mmHg within a limited time period. Only dorsal recumbency increased the need of dobutamine administration., Competing Interests: Declaration of Competing Interest This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Objectives: This study compared the effectiveness of a new supraglottic airway device (SGAD) in cats undergoing anaesthesia using two types of mechanical ventilation: volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV)., Methods: A total of 13 healthy cats (five male, eight female; median age 2 years [range 1-3]) were randomly allocated to either VCV or PCV. Five tidal volumes (6, 8, 10, 12 and 14 ml/kg) and five peak inspiratory pressures (4, 5, 6, 7 and 8 cmH 2 O) were randomly applied with a minute ventilation of 100 ml/kg/min. Various parameters, such as blood pressure, gas leakage, end-tidal CO 2 (ETCO 2 ) and work of breathing (WOB), were measured while using VCV or PCV., Results: The occurrence of hypotension (mean arterial blood pressure <60 mmHg) was slightly less frequent with VCV (38 events, 65 ventilating sessions) than with PCV (40 events, 65 ventilating sessions), but this difference did not reach statistical significance ( P  = 0.429). The number of leakages did not differ between the VCV group (3 events, 65 ventilating sessions) and the PCV group (3 events, 65 ventilating sessions) ( P  = 1.000). Hypercapnia was identified when using VCV (10 events, 65 ventilating sessions) less frequently than when using PCV (17 events, 65 ventilating sessions), but this difference did not reach statistical significance ( P  = 0.194). The study found a significantly higher WOB in the PCV group compared with the VCV group ( P <0.034)., Conclusions and Relevance: The present results suggested that both VCV and PCV can be used with an SGAD during anaesthesia, with VCV preferred for prolonged mechanical ventilation due to its lower workload. Adjusting tidal volume or inspiratory pressure corrects hypercapnia., Competing Interests: Conflict of interestThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Cownose rays ( Rhinoptera bonasus ) are susceptible to ocular disease with their prominent globes, but despite being popular animals housed in aquaria, there is little published information about their normal ocular anatomy and common pathologic ocular findings. A total of 63 live cownose rays (CNR) from three unrelated, separately housed groups had ocular examinations, and 5 adult rays were selected for ocular ultrasound. All examinations were performed out of the water, and most without anesthesia. Clinical findings were described, categorized, and scored by severity. Sixty-two of 63 rays (123 eyes) had clinical abnormalities, including 110 eyes with corneal pathology (mild = 76, moderate/severe = 34) and 74 eyes with intraocular pathology (mild = 44, moderate/severe = 30). Grey-to-white corneal opacities were the most common pathology (n = 58 rays/100 eyes) followed by cataracts (n = 41 rays/58 eyes), then persistent (or dysplastic) pupillary membranes (n = 14 rays/15 eyes). Most pathologic findings appeared inactive, but one aquarium had several CNR with active ocular pathology. There was a significant association between the diagnosis of moderate/severe corneal and intraocular pathology with age ( P = 0.008 and P = 0.014, respectively) and weight ( P = 0.001 and P = 0.039, respectively), as well as moderate/severe corneal pathology and group sampled ( P = 0.03). There were no other significant variables identified. Additionally, histopathology of 14 eyes (11 rays) from two different facilities were examined, with keratitis (n = 8) and uveitis (n = 2) as the most common lesions. This study shows a high prevalence of pathologic ocular findings in cownose ray eyes with heavier adults more likely to be affected than lighter juveniles. Comprehensive ocular evaluation is important in this species and serial ocular exams and future studies should be pursued to monitor ocular disease progression and better understand possible etiologies.

The research use of zebrafish has risen exponentially over the past decade while anesthetic options have remained largely unchanged. 6 ricaine methanesulfonate (MS-222) is widely accepted as an anesthetic for routine husbandry procedures, however it has limitations and safety concerns. 11 A greater variety of effective anesthetic options for surgical procedures would be advantageous for the research community. Adult zebrafish were randomly assigned to one of the following groups ( n = 10, 5 males and 5 females): 200 mg/L MS-222; 6-, 10-, 13-, and 16-mg/L alfaxalone, and control. All zebrafish in the MS-222 group reached a surgical plane of anesthesia within 95 ± 32 s. By contrast, only 2 of 10, 1 of 10, 0 of 10, and 0 of 4 of the 6, 10, 13, and 16 mg/L alfaxalone groups, respectively, reached a surgical plane of anesthesia within the allotted 10-min period. Recovery time was also significantly slower in the alfaxalone groups as compared with MS-222, with some fish taking greater than 10 min to recover. In addition, 33 of 34 zebrafish (the 16 mg/L group was not completed due to safety concerns) in the alfaxalone groups lost opercular movements for greater than one minute during their anesthetic event and had to be removed to the recovery tank. The results demonstrated that alfaxalone was unable to provide a reliable and safe surgical plane of anesthesia at any of the drug doses tested. Therefore, we recommend alfaxalone not be used as an anesthetic for painful procedures on zebrafish and conclude that MS-222 remains a more viable anesthetic for immersion anesthesia in zebrafish.

Alfaxalone is a commonly used injectable anesthetic in dogs and cats due to its minimal cardiovascular side effects. Data for its use in mice are limited and demonstrate strain- and sex-associated differences in dose-response relationships. We performed a dose-comparison study of alfaxalone-xylazine-buprenorphine (AXB) in Crl: CFW (SW) mice. Subcutaneous injection of 50 mg/kg alfaxalone-10 mg/kg xylazine-0.1 mg/kg buprenorphine HCl consistently achieved a surgical plane of anesthesia (loss of toe pinch) for 48.6 ± 4.7 and 60.8 ± 9.6 min in females and males, respectively. The same dose and route of AXB induced a surgical plane of anesthesia in C57Bl/6NCrl (females: 42.3 ± 11.2 min; males: 51.6 ± 12.3 min), NCr-Foxn1 nu (females: 76.8 ± 32.5 min; males: 80.0 ± 1.2 min), and NOD. Cg-Prkdc SCID Il2rg tm1Wjl /SzJCr (females: 56.0 ± 37.2 min and males: 61.2 ± 10.2 min) mice. We found no significant difference in the duration of the surgical plane of anesthesia between males and females within the mouse strains Crl: CFW (SW), C57Bl/6NCrl, NCr-Foxn1 nu , and NOD. Cg-Prkdc SCID Il2rg tm1Wjl /SzJCr. We next performed an echocardiography study ( n = 5 per group) of Crl: CFW (SW) mice ( n = 5 per group) to compare subcutaneous AXB anesthesia with that produced by intraperitoneal injection of 100 mg/kg ketamine and 10 mg/kg xylazine (KX). AXB induced significantly less bradycardia (295.4 ± 29 bpm) than KX (185.8 ± 38.9 bpm) did, with no significant differences in cardiac output, ejection fraction, end-diastolic volume, end-systolic volume, or fractional shortening. These results suggest that subcutaneous administration of AXB is a viable alternative to KX for inducing a surgical plane of anesthesia in Crl: CFW (SW), C57Bl/6NCrl, NCr-Foxn1 nu , and NOD. Cg-Prkdc SCID Il2rg tm1Wjl /SzJCr mice, regardless of sex. AXB may also be a better injectable anesthetic option as compared with KX for avoiding adverse cardiac effects in mice.

Objective: This study compared the quality of retrobulbar anesthesia using a blind inferior-temporal palpebral approach (ITP) with an ultrasound-guided supratemporal (ST) technique in dogs undergoing unilateral enucleation., Animal Studied: Twenty-one client-owned dogs were undergoing enucleation., Procedures: Dogs were randomly assigned to receive ITP (n = 10) or ST (n = 11) with 0.5% ropivacaine at 0.1 mL/cm of neurocranial length. The anesthetist was blinded to the technique. Intraoperative data included cardiopulmonary variables, inhalant anesthetics requirement, and requirement for rescue analgesia (intravenous fentanyl 2.5 mcg/kg). Postoperative data included pain scores, sedation scores, and need for intravenous hydromorphone (0.05 mg/kg). Treatments were compared using Wilcoxon's rank sum test or Fisher's exact test as appropriate. Comparison of variables over time were tested using a mixed effect linear model on rank. Significance was set at p = 0.05., Results: Intraoperative cardiopulmonary variables and inhalant requirements were not different between groups. Dogs receiving ITP required median (interquartile range, IQR) 1.25 (0, 2.5) mcg/kg intraoperative fentanyl while those receiving ST required none (p < 0.01). Intraoperative fentanyl was required in 5/10 and 0/11 of dogs in the ITP and ST groups, respectively (p = 0.01). Postoperative analgesia requirements were not significantly different between groups; 2/10 and 1/10 dogs in the ITP and ST groups, respectively. Sedation score negatively affected pain score (p < 0.01)., Conclusions: The ultrasound-guided ST technique was more effective at decreasing intraoperative opioid requirements than the blind ITP approach in dogs undergoing unilateral enucleation., (© 2023 The Authors. Veterinary Ophthalmology published by Wiley Periodicals LLC on behalf of American College of Veterinary Ophthalmologists.)

Introduction: This study observed the effects of oxygen supplementation, via an oxygen concentrator, on peripheral arterial blood oxygenation (SpO2) measured by pulse oximetry in anaesthetised cats undergoing spay in three different surgical positions. A total of 192 female feral cats were investigated for a large-scale trap-neuter-release program. Cats were anaesthetised with an intramuscular combination of butorphanol (0,4 mg / kg), ketamine (7-10 mg / kg) and medetomidine (0,03-0,05 mg / kg). Cats were randomly allocated to undergo spay in either Trendelenburg (TR) (70° downward head tilt), lateral (LR) or dorsal (DR) recumbency. Cats were breathing spontaneously either room air or 2 L/minute oxygen via a tight-fitting face mask. Pulse rate (in beats per minute), respiratory rate (in breaths per minute) and SpO2 (in percentage) were measured at baseline in left lateral recumbency and afterwards continuously after being positioned in allocated surgical position. At the end of surgery, cats were placed again in left recumbency, and all parameters were re-evaluated after five minutes. Overall, 33 % of cats showed severe arterial oxygen desaturation (SpO2 < 90 %) at baseline when breathing room air. When oxygen was supplemented during the procedure, arterial oxygen desaturation resolved in all cats. At the end of the procedure, 29 % of cats were hypoxaemic when oxygen was not supplemented, with an overall higher percentage of hypoxaemic cats in TR as compared to DR and LR recumbencies. All cats recovered well from surgery and were released within 24 hours post-anaesthesia. Arterial oxygen desaturation is frequent in cats anaesthetised with injectable anaesthesia for spay under field conditions. Oxygen supplementation administered via a tight-fitting mask resolved arterial oxygen desaturation in this feral cat population regardless of the surgical position and therefore oxygen supplementation is recommended in any case.

One male and one female giant panda ( Ailuropoda melanoleuca ) from a Belgian zoo were anesthetized on eight different occasions over a course of 4 yr for electro-ejaculation ( n = 3) or artificial insemination ( n = 5). Medetomidine (0.03-0.04 mg/kg) and ketamine (2.5-3 mg/kg) were administered by intramuscular remote injection. Animals gained sternal recumbency with the loss of response to external stimuli after 4.9 ± 1.6 min (mean ± SD). The trachea was intubated with a 14-mm-internal diameter endotracheal tube; anesthesia was maintained with isoflurane in oxygen adjusted according to the required depth of anesthesia with a small-animal circle system. Physiological variables (heart rate, respiratory rate, oxygenation, end tidal carbon dioxide partial pressure and non-invasive blood pressure) were measured and remained within an acceptable range throughout anesthesia. Atipamezole (0.17-0.25 mg/kg) was administered intramuscularly after anesthesia. Recoveries were rapid and uneventful. Medetomidine 0.03 mg/kg and ketamine 2.5 mg/kg IM appeared to be the preferred doses for giant pandas.

Mechanical ventilation can be used in mice to support high-risk anesthesia or to create clinically relevant, intensive care models. However, the choice of anesthetic and inspired oxygen concentration for prolonged procedures may affect basic physiology and lung inflammation. To characterize the effects of anesthetics and oxygen concentration in mice experiencing mechanical ventilation, mice were anesthetized with either isoflurane or pentobarbital for tracheostomy followed by mechanical ventilation with either 100% or 21% oxygen. Body temperature, oxygen saturation, and pulse rate were monitored continuously. After 6 h, mice were euthanized for collection of blood and bronchoalveolar lavage fluid for evaluation of biomarkers of inflammation and lung injury, including cell counts and cytokine levels. Overall, both isoflurane and pentobarbital provided suitable anesthesia for 6 h of mechanical ventilation with either 21% or 100% oxygen. We found no differences in lung inflammation biomarkers attributable to either oxygen concentration or the anesthetic. However, the combination of pentobarbital and 100% oxygen resulted in a significantly higher concentration of a biomarker for lung epithelial cell injury. This study demonstrates that the combination of anesthetic agent, mechanical ventilation, and inspired oxygen concentrations can alter vital signs and lung injury biomarkers during prolonged procedures. Their combined impact may influence model development and the interpretation of research results, warranting the need for preliminary evaluation to establish the baseline effects.

We developed a venipuncture technique of the ventral caudal vein in conscious Virginia opossums (Didelphis virginiana) in cage traps, enabling blood sampling without anesthesia. Blood samples were successfully collected from all 28 opossums in this study by this technique. Draw volume of <0.1 mL occurred in only four opossums (14%)., (© Wildlife Disease Association 2024.)

Objective: To compare the effects of oral pregabalin versus gabapentin on sedation quality and anesthesia recovery times in cats in a typical perioperative setting., Animals: 50 healthy cats with > 1 kg body weight presenting for elective surgery., Methods: In this randomized, prospective clinical trial, cats presenting to the University of California-Davis Veterinary Medical Teaching Hospital were assigned to receive buprenorphine 0.02 mg/kg IM followed by 1 of 2 oral sedation treatments: pregabalin 4 mg/kg or gabapentin 10 mg/kg. Cats were then anesthetized using a standardized protocol. Physical examination parameters and behavioral scores were measured by 2 treatment-blinded veterinarians to compare sedation levels before and after drug administration. Inadequate sedation for handling or IV catheter placement was addressed by dexmedetomidine administration. After surgery was completed, anesthesia recovery times and quality were assessed by the same veterinarians. The effects of pregabalin versus gabapentin on body temperature, respiratory rate, and heart rate were analyzed using Student t tests; behavioral assessments were analyzed using Wilcoxon signed-rank tests; and drug treatment effects on dexmedetomidine sedation rescue and frequency of delirium during anesthetic recovery were analyzed using Fisher exact tests. A P < .05 indicated statistical significance., Results: There was no significant difference in change of physiologic parameters or sedation scores before and after sedation between groups. The need for rescue sedation for IV catheter placement and the incidence of emergence delirium were infrequent and similar for both treatments., Clinical Relevance: At the doses studied, oral pregabalin and gabapentin produced indistinguishable effects as adjunctive perioperative sedation agents in cats.

The present paper reports on the clinical efficacy and optimal clinical dose of medetomidine for sedation of young cows during dehorning surgery. Medical records of 24 female Holstein cows that underwent dehorning surgery were used in this study. In four groups, the sedation of animals was carried out by one of the four intravenous treatments: 0.1 mg kg-1 xylazine (Xyl group, n = 6), 5.0 μg kg-1 medetomidine (5.0 Med group, n = 6), 10.0 μg kg-1 medetomidine (10.0 Med group, n = 6) or 20.0 μg kg-1 medetomidine (20.0 Med group, n = 6). The clinical sedation score (CSS) and heart rate (HR) were recorded. The CSSs after intravenous administration of each α2-adrenergic receptor agonist increased rapidly and peaked at 12.5 (10.0-16.0) at t = 20 min in the Xyl group, 11.5 (10.0-15.0) at t = 10 min in the 5.0 Med group, 16.0 (14.0-16.0) at t = 20 min in the 10.0 Med group and 16.0 (14.0 - 16.0) at t = 20 min in the 20.0 Med group. A similar degree of bradycardia was observed after every sedative treatment. We conclude that the intravenous administration of 10.0-20.0 μg kg-1 medetomidine is appropriate for sedation of young cows without severe side effects.