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Objectives To compare pulmonary gas exchange, tissue oxygenation and cardiovascular effects of four levels of end-expiratory pressure: no positive end-expiratory pressure (ZEEP), positive end-expiratory pressure (PEEP) of maximal respiratory system compliance (PEEPmaxCrs), PEEPmaxCrs + 2 cmH2O (PEEPmaxCrs+2), PEEPmaxCrs + 4 cmH2O (PEEPmaxCrs+4), in isoflurane-anesthetized dogs. Study design Prospective randomized crossover study. Animals A total of seven healthy male Beagle dogs, aged 1 year and weighing 10.2 ± 0.7 kg (mean ± standard deviation). Methods The dogs were administered acepromazine and anesthesia was induced with propofol and maintained with isoflurane. Ventilation was controlled for 4 hours with ZEEP, PEEPmaxCrs, PEEPmaxCrs+2 or PEEPmaxCrs+4. Cardiovascular, pulmonary gas exchange and tissue oxygenation data were evaluated at 5, 60, 120, 180 and 240 minutes of ventilation and compared using a mixed-model anova followed by Bonferroni test. p Results Cardiac index (CI) and mean arterial pressure (MAP) were lower in all PEEP treatments at 5 minutes when compared with ZEEP. CI persisted lower throughout the 4 hours only in PEEPmaxCrs+4 with the lowest CI at 5 minutes (2.15 ± 0.70 versus 3.45 ± 0.94 L minute–1 m–2). At 180 and 240 minutes, MAP was lower in PEEPmaxCrs+4 than in PEEPmaxCrs, with the lowest value at 180 minutes (58 ± 7 versus 67 ± 7 mmHg). Oxygen delivery index (DO2I) was lower in PEEPmaxCrs+4 than in ZEEP at 5, 60, 120 and 180 minutes. Venous admixture was not different among treatments. Conclusion and clinical relevance The use of PEEP caused a transient decrease in MAP and CI in lung-healthy dogs anesthetized with isoflurane, which improved after 60 minutes of ventilation in all levels of PEEP except PEEPmaxCrs+4. A clinically significant improvement in arterial oxygenation and DO2I was not observed with PEEPmaxCrs and PEEPmaxCrs+2 in comparison with ZEEP, whereas PEEPmaxCrs+4 decreased DO2I.

ObjectivesTo compare the effects of four levels of end-expiratory pressure [zero (ZEEP) and three levels of positive end-expiratory pressure (PEEP)] on the cardiovascular system and gas exchange of cats anesthetized with isoflurane and mechanically ventilated for 3 h with a tidal volume of 10 ml/kg.Study DesignProspective, randomized, controlled trial.AnimalsSix healthy male neutered purpose-bred cats.MethodsAnesthesia was induced with isoflurane and maintained at 1.3 minimum alveolar concentration. PEEP of maximal respiratory compliance (PEEPmaxCrs) was identified in a decremental PEEP titration, and cats were randomly ventilated for 3 h with one of the following end-expiratory pressures: ZEEP, PEEPmaxCrs minus 2 cmH2O (PEEPmaxCrs−2), PEEPmaxCrs, and PEEPmaxCrs plus 2 cmH2O (PEEPmaxCrs+2). Cardiovascular and gas exchange variables were recorded at 5, 30, 60, 120, and 180 min (T5 to T180, respectively) of ventilation and compared between and within ventilation treatments with mixed-model ANOVA followed by Dunnet's and Tukey's tests (normal distribution) or Friedman test followed by the Dunn's test (non-normal distribution). Significance to reject the null hypothesis was considered p < 0.05.ResultsMean arterial pressure (MAP—mmHg) was lower in PEEPmaxCrs+2 [63 (49–69); median (range)] when compared to ZEEP [71 (67–113)] at T5 and stroke index (ml/beat/kg) was lower in PEEPmaxCrs+2 (0.70 ± 0.20; mean ± SD) than in ZEEP (0.90 ± 0.20) at T60. Cardiac index, oxygen delivery index (DO2I), systemic vascular resistance index, and shunt fraction were not significantly different between treatments. The ratio between arterial partial pressure and inspired concentration of oxygen (PaO2/FIO2) was lower in ZEEP than in the PEEP treatments at various time points. At T180, DO2I was higher when compared to T5 in PEEPmaxCrs. Dopamine was required to maintain MAP higher than 60 mmHg in one cat during PEEPmaxCrs and in three cats during PEEPmaxCrs+2.ConclusionIn cats anesthetized with isoflurane and mechanically ventilated for 3 h, all levels of PEEP mildly improved gas exchange with no significant difference in DO2I when compared to ZEEP. The PEEP levels higher than PEEPmaxCrs−2 caused more cardiovascular depression, and dopamine was an effective treatment. A temporal increase in DO2I was observed in the cats ventilated with PEEPmaxCrs. The effects of these levels of PEEP on respiratory mechanics, ventilation-induced lung injury, as well as in obese and critically ill cats deserve future investigation for a better understanding of the clinical use of PEEP in this species.

Simple Summary In anaesthetized horses, blood oxygenation impairment often occurs. This systematic review compared the effects of low and high inspired oxygen fractions on the arterial oxygen tension and other pulmonary gas exchange parameters in horses during inhalation anaesthesia. Five studies, four experimental and one clinical, were deemed suitable for inclusion. A meta-analysis was performed on the four experimental studies. The oxygen partial pressure was significantly lower with a lower inspired oxygen fraction. However, indices of pulmonary gas exchange were significantly worsened. It is concluded that, while only a limited number of studies are available, the use of a higher inspired oxygen fraction in horses during inhalation anaesthesia will result in higher levels of oxygen in the blood; it will also worsen the lung gas exchange status. Further studies are needed to increase the level of evidence on this subject. In anaesthetized horses, pronounced ventilation/perfusion mismatching often occurs. Several authors have investigated the effect of lower inspired oxygen fractions (FiO(2)) to reduce formation of absorption atelectasis. This systematic review compared the effects of low (0.8) FiO(2) on the arterial oxygen tension (PaO2), the alveolar-to-arterial oxygen tension difference (P(A-a)O-2), and the PaO2/FiO(2) ratio in horses during inhalation anaesthesia. Using the Systematic Review Protocol for Animal Intervention Studies, four experimental and one clinical investigations were deemed suitable for inclusion. A meta-analysis was performed on the four experimental studies. The PaO2 was significantly lower (p = 0.0007, mean difference -23.54 kPa, 95% CI -37.18, -9.90) with a lower FiO(2). However, the P(A-a)O-2 was also significantly lower (p < 0.00001, mean difference -20.80 kPa, 95% CI -26.28, -15.32) when using a low FiO(2). For the PaO2/FiO(2) ratio, only one study fitted the inclusion criteria, so no meta-analysis was performed. It is concluded that, while only a limited number of studies are available, the use of a higher FiO(2) in horses during inhalation anaesthesia will result in higher levels of PaO2, but also a larger P(A-a)O-2 difference. Further studies are needed to increase the level of evidence on this subject.

Objective To evaluate the influence of reservoir bag types, volumes and previous use on the peak pressures (Pmax) and the times to develop 30 cmH2O pressure (P30) within a nonrebreathing system with a closed adjustable pressure-limiting (APL) valve. Study design In vitro study using three-way factorial design with repeated measure on one factor. Subjects A total of 75 new anesthesia reservoir bags (five types, three volumes, five bags from each type × volume). The bag types were reusable latex (RL), disposable latex (DL) and three disposable neoprene (DN-1, DN-2 and DN-3). Methods Each bag was tested three times (treatments): new, after prestretching and 1 week later. The bags were attached to a Bain system and anesthesia machine with closed APL valve and patient port with O2 flow 2 L minute–1 until Pmax was reached. The Pmax and time to reach P30 values were determined from recorded pressure traces. General linear mixed model analysis was used to examine the effects of bag type, volume and treatment. One-sided 95% upper prediction limits of Pmax were calculated to test the null hypothesis that predicted Pmax of new bags would be ≥ 50 cmH2O for each factor combination. Results RL bags were the least and DN-3 bags were the most compliant. Prestretching increased compliance in all bag types. Smaller bags of RL, DL and DN-1 were less compliant than larger ones. The predicted Pmax values were Conclusions and clinical relevance To minimize the risk of barotrauma, highly compliant reservoir bags (e.g. DN-3) are recommended and reusable bags should be avoided. Bags should be prestretched before first use, 0.5 L bags should be avoided and fresh gas flow minimized.

The global prevalence of diabetes mellitus and other metabolic diseases is rapidly increasing. Animal models play pivotal roles in unravelling disease mechanisms and developing and testing therapeutic strategies. Rodents are the most widely used animal models but may have limitations in their resemblance to human disease mechanisms and phenotypes. Findings in rodent models are consequently often difficult to extrapolate to human clinical trials. To overcome this ‘translational gap’, we and other groups are developing porcine disease models. Pigs share many anatomical and physiological traits with humans and thus hold great promise as translational animal models. Importantly, the toolbox for genetic engineering of pigs is rapidly expanding. Human disease mechanisms and targets can therefore be reproduced in pigs on a molecular level, resulting in precise and predictive porcine (PPP) models. In this short review, we summarize our work on the development of genetically (pre)diabetic pig models and how they have been used to study disease mechanisms and test therapeutic strategies. This includes the generation of reporter pigs for studying beta-cell maturation and physiology. Furthermore, genetically engineered pigs are promising donors of pancreatic islets for xenotransplantation. In summary, genetically tailored pig models have become an important link in the chain of translational diabetes and metabolic research.

Objective To evaluate the pharmacokinetics and selected pharmacodynamic effects of a commercially available l -methadone/fenpipramide combination administered to isoflurane anaesthetized ponies. Study design Prospective single-group interventional study. Animals A group of six healthy adult research ponies (four mares, two geldings). Methods Ponies were sedated with intravenous (IV) detomidine (0.02 mg kg–1) and butorphanol (0.01 mg kg–1) for an unrelated study. Additional IV detomidine (0.004 mg kg–1) was administered 85 minutes later, followed by induction of anaesthesia using IV diazepam (0.05 mg kg–1) and ketamine (2.2 mg kg–1). Anaesthesia was maintained with isoflurane in oxygen. Baseline readings were taken after 15 minutes of stable isoflurane anaesthesia. l -Methadone (0.25 mg kg–1) with fenpipramide (0.0125 mg kg–1) was then administered IV. Selected cardiorespiratory variables were recorded every 10 minutes and compared to baseline using the Wilcoxon signed-rank test. Adverse events were recorded. Arterial plasma samples for analysis of plasma concentrations and pharmacokinetics of l -methadone were collected throughout anaesthesia at predetermined time points. Data are shown as mean ± standard deviation or median and interquartile range (p Results Plasma concentrations of l -methadone showed a rapid initial distribution phase followed by a slower elimination phase which is best described with a two-compartment model. The terminal half-life was 44.3 ± 18.0 minutes, volume of distribution 0.43 ± 0.12 L kg–1 and plasma clearance 7.77 ± 1.98 mL minute–1 kg–1. Mean arterial blood pressure increased from 85 (±16) at baseline to 100 (±26) 10 minutes after l -methadone/fenpipramide administration (p = 0.031). Heart rate remained constant. In two ponies fasciculations occurred at different time points after l -methadone administration. Conclusions and clinical relevance Administration of a l -methadone/fenpipramide combination to isoflurane anaesthetized ponies led to a transient increase in blood pressure without concurrent increases in heart rate. Pharmacokinetics of l -methadone were similar to those reported for conscious horses administered racemic methadone.

Objective To assess changes in the distribution in pulmonary ventilation in anaesthetized ponies using Electrical Impedance Tomography (EIT). Study design Prospective experimental study Animals Eight adult ponies geldings Methods General anaesthesia was induced and maintained using isoflurane in oxygen with volume-controlled ventilation [tidal volume (10 mL kg-1), respiratory rate (8 – 12 breaths minute-1)] to maintain end-tidal carbon dioxide between 35 and 40 mmHg (4.66–5.32 kPa). Regional distribution of ventilation was assessed with EIT (plane of 5th to 6th intercostal space) at 30, 60 and 90 minutes after intubation. The resulting functional images were divided into four regions of interest (ROI, A - D) to determine 1) the ratio of tidal volume distribution between dependent to non-dependent lung (D/ND), 2) changes in distribution within the lungs in latero-lateral direction. The centre of ventilation (COV) was calculated. The dimension of the chest in latero-lateral (W) and dorso-ventral (H) direction was measured at the height of the withers and the W/H ratio was calculated. The influence of time on D/ND ratio, COV and ROI A – D were analysed with ANOVA followed by post-hoc Bonferroni tests. Pearson correlation coefficient and the coefficient of determination (r2) were calculated to evaluate the relationship between W/H ratio and D/ND ratio, and COV. Statistical significance was set at p < 0.05. Results The median D/ND ratio (T30 to T90) was 0.67 (0.40 -1.01) and for COV 31.15% (11.20-45.20), confirming the expected uneven distribution of ventilation. The D/ND ratio had a moderate negative correlation with the W/H ratio (r = -0.68, r2 = 0.46, p = 0.000), while the COV did not correlate with the W/H ratio (r = -0.04). Conclusion and clinical relevance: Uneven ventilation in mechanically ventilated right laterally recumbent anaesthetised ponies occurs within thirty minutes and changed little over the following 60 minutes.

Quantitative computer tomographic analysis (qCTA) is an accurate but time intensive method used to quantify volume, mass and aeration of the lungs. The aim of this study was to validate a time efficient interpolation technique for application of qCTA in ponies. Forty-one thoracic computer tomographic (CT) scans obtained from eight anaesthetised ponies positioned in dorsal recumbency were included. Total lung volume and mass and their distribution into four compartments (non-aerated, poorly aerated, normally aerated and hyperaerated; defined based on the attenuation in Hounsfield Units) were determined for the entire lung from all 5 mm thick CT-images, 59 (55–66) per animal. An interpolation technique validated for use in humans was then applied to calculate qCTA results for lung volumes and masses from only 10, 12, and 14 selected CT-images per scan. The time required for both procedures was recorded. Results were compared statistically using the Bland–Altman approach. The bias ± 2 SD for total lung volume calculated from interpolation of 10, 12, and 14 CT-images was −1.2 ± 5.8%, 0.1 ± 3.5%, and 0.0 ± 2.5%, respectively. The corresponding results for total lung mass were −1.1 ± 5.9%, 0.0 ± 3.5%, and 0.0 ± 3.0%. The average time for analysis of one thoracic CT-scan using the interpolation method was 1.5–2 h compared to 8 h for analysis of all images of one complete thoracic CT-scan. The calculation of pulmonary qCTA data by interpolation from 12 CT-images was applicable for equine lung CT-scans and reduced the time required for analysis by 75%.

Tetralogy of Fallot (ToF) is a rare congenital cardiac disease, which has been described in many species, including cats. It often causes cyanosis due to deoxygenated blood entering the systemic circulation. The prognosis of uncorrected ToF is generally poor, but some individuals with mild forms of the disease can survive beyond three years of age. A cat with mild, asymptomatic ToF was anaesthetised for elective ovariectomy. The cat was premedicated intramuscularly with methadone and alfaxalone. Anaesthesia was induced with alfaxalone and midazolam and maintained with sevoflurane in oxygen using mechanical ventilation. Intraoperative analgesia was provided with a constant rate infusion of fentanyl and local anaesthesia. Phenylephrine was infused during anaesthesia to maintain adequate systemic vascular resistance. Mild bradycardia during ovarian tissue handling was treated successfully with atropine. Meloxicam and buprenorphine were used to provide postoperative analgesia. The cat did not experience major complications during anaesthesia and made a full recovery.

A six-year-old Shetland pony stallion was presented for elective castration. During surgical preparations, undiluted heparin (120 iu/kg) was unintentionally used for intravenous catheter flushing instead of heparinised saline solution. Surgery was cancelled for that day. Thromboelastography was used to monitor blood coagulation immediately after the accidental heparin overdose and on the following days. Three days after the heparin overdose, the coagulation parameters had returned to normal values and the pony was castrated. Anaesthesia and surgery were uneventful without any signs of coagulopathy. One day after surgery, the pony started to show signs of colic and was further diagnosed with colitis, most likely unrelated to heparin but due to repeated administration of penicillin and anaesthesia. Despite intensive treatment, the pony deteriorated progressively and was euthanased due to poor prognosis. Drug overdose is an example of medication error and is one of the most common errors in medicine.

Objective To assess publication rates, factors predicting publication, and discrepancies between conference abstracts and subsequent full-text publications of abstracts from the veterinary meetings of the American College of Veterinary Anesthesiologists and the Association of Veterinary Anaesthetists from 2003 to 2008. Study design Retrospective cohort study. Methods A total of 607 abstracts were identified and a database search (Scopus, PubMed, CAB) was conducted to identify matching publications. Authors of nonmatching abstracts were contacted to participate in a confidential online survey. Risk ratios were used to assess factors predicting publication and these were tested for significance (p Results The overall publication rate was 63.3% and the mean (± SD) time to publication was 25 ± 19 months. Factors significantly associated with subsequent full publication (i.e. publication of a full manuscript in a peer-reviewed journal) were continent of origin (North America), study design (experimental studies), specialty (analgesia) and the presence of a source of funding. The principal reasons why studies remained unpublished were lack of time and responsibility lying with co-authors. Minor changes compared with the original abstract were found in 71.6% of all publications. Major changes were noted in 34.6% and the outcome of the study changed in 7.6%. Conclusions and clinical relevance These data suggest that some of the abstracts reported preliminary findings. Therefore, caution is warranted when quoting abstracts as references in scientific publications. To date, major veterinary journals have not issued recommendations in their author guidelines addressing the use of abstracts as a reference. The authors propose the inclusion of such a statement in author guidelines.

Objective To determine the incidence of anesthesia patient safety incidents at a university teaching hospital, develop interventions to address the most common incidents, and determine the effectiveness of these interventions. Study design Pre-post intervention observational. Animals Four thousand, one hundred forty dogs and cats anesthetized by the anesthesia service. Methods The study was divided into two 11.5 month periods. During each period, incidents were logged (e.g. closed adjustable pressure limiting (APL) valve, esophageal intubation, and medication error). At the end of the first period, four countermeasures were incorporated into the service’s protocols: 1) prior to any drug injection, the individual would read out aloud the drug name, patient name, and route of administration; 2) use of a uniquely colored occlusive wrap over arterial catheters; 3) a check box on the anesthesia record labeled “Technician Confirmed Intubation”; 4) a check box on the anesthesia record labeled “Technician Checked OR (operating room)”. The number of patient safety incidents during period 1 and period 2 were compared using Fisher’s Exact Test. Results During Period 1, there were 74 incidents documented in 2028 patients (3.6%) including 25 medication errors, 20 closed APL valves, and 16 of esophageal intubation. During Period 2, there were 30 incidents documented in 2112 patients (1.4%) including 14 medication errors, 5 closed APL valves, and 4 of esophageal intubation. The proportion of events during Period 2 was significantly smaller than during Period 1 (p Conclusions and Clinical relevance Implementation of four simple interventions was associated with a significant decrease in the number of incidents.

Objective This study compares the pharmacodynamics of two different doses of alfaxalone administered intramuscularly (IM) to red‐eared sliders at two ambient temperatures. Study design Prospective blinded crossover experimental study. Animals Nine adult female sliders ( Trachemys scripta elegans ). Methods Following a 2‐week acclimation at 22–25 °C, nine sliders were randomly assigned to receive alfaxalone, 10 mg kg −1 (W10), or 20 mg kg −1 (W20) IM. Each turtle received each dose, with a minimum 7‐day washout period. A blinded observer evaluated heart rate (HR), palpebral and corneal reflexes, muscle relaxation, handling, and response to toe pinch at the following points: pre‐injection, and 5, 12, 20, 30, 45, 60, and 120 minutes post‐injection. Turtles then acclimated to 18–20 °C for 63 days, and the experiment was repeated in this lower‐temperature environment, with treatment groups C10 (alfaxalone 10 mg kg −1 ) and C20 (alfaxalone 20 mg kg −1 ) subjected to the same crossover design. Results C10 and C20 groups had significantly lower intraanesthetic HR than W10 or W20, respectively. C10 and W20 were significantly more relaxed and easier to handle than W10. No significant differences were observed in palpebral reflex, nor responsiveness to the toe pinch stimulus. None of the turtles lost corneal reflex. W20 and C20 had prolonged recoveries, compared to low‐dose groups within the same temperature environment. Recovery was also longer at C20 and C10 compared to W10. Conclusions Turtles given 10 mg kg −1 were more relaxed and easier to handle in cold than warm conditions. Warm turtles were more relaxed and easier to handle when given 20 mg kg −1 than those given 10 mg kg −1 . Cold conditions correlated with lower HR and longer recovery time for each dose category. Clinical relevance The turtles had dose‐dependent and inconsistent responses to alfaxalone. Lower ambient temperature augmented the behavioral effects of this drug.

Objective—To determine whether a heat and moisture exchange device (HME) prevents a decrease in body temperature in isoflurane-anesthetized dogs undergoing orthopedic procedures. Design—Blinded randomized controlled clinical trial. Animals—60 privately owned dogs weighing at least 15 kg (33 lb). Procedures—Dogs were randomly assigned to 1 of 3 treatment groups (n = 20/group): HME placed immediately after anesthetic induction with isoflurane, after transfer to the operating room, or not at all. The device consisted of a hygroscopic filter placed between the endotracheal tube and the Y piece of the anesthesia circuit. Each dog was positioned on a circulating warm water blanket and had a forced-air warming blanket placed over its body. Body temperature was monitored after transfer to the operating room with a probe placed in the thoracic aspect of the esophagus. Results—Study groups did not differ significantly with respect to body weight, body condition score, reproductive status, breed, surgical procedure, preoperative sedative and opioid administration, anesthetic induction drug, local nerve block technique, or operating room assignment. There were no significant differences among groups in esophageal temperature variables, interval between anesthetic induction and surgery, surgery duration, anesthesia duration, or oxygen flow rate. However, the relationship between temperature delta and body weight was significant and relevant (R2 = 0.23), as was the association between temperature nadir and body weight (R2= 0.10). As body weight increased, the temperature delta decreased and temperature nadir increased. No other significant relationships were identified. Conclusions and Clinical Relevance—Inclusion of an HME in healthy dogs undergoing anesthesia for an elective orthopedic surgery did not facilitate maintenance of body temperature throughout the procedure.

Objective To investigate the efficacy of maxillary and infraorbital nerve blocks for prevention of cardiovascular and qualitative responses to rhinoscopy, as well as response to skin clamping after assigned nerve block placement. Study design Randomized, blinded, placebo‐controlled cross‐over experimental study. Animals Eight random‐source mixed breed dogs > 1 year old and weighing between 13 and 22 kg. Methods Within three anesthetic episodes, separated by at least 3 days, dogs were assigned to receive either 1 mL lidocaine 2% maxillary nerve block (ML); 0.5 mL lidocaine 2% infraorbital nerve block (IOL); or equal amounts of saline for maxillary or infraorbital nerve block combined as control treatment (S). Monitoring included temperature, respiratory rate, end‐tidal CO2, ECG, heart rate (HR), systolic, diastolic and mean arterial pressure (SAP, DAP, MAP). Posterior (pR) and anterior rhinoscopies (aR) were performed and scored. Differences from baseline for outcome parameters HR, SAP, DAP, MAP were analyzed using repeated‐measures anova , and results reported as mean ± SD. Binary scores for rhinoscopy were analyzed using logistic regression, and odds ratio was reported. Results Changes from baseline for HR and SAP were significant for all treatments, besides ML for pR. Difference in changes from baseline among treatments was statistically significant for HR during pR with ML ML, except for DAP in left aR with only IOL > ML. Analysis of the binary score showed that the probability of a response for S and IOL treatments was nearly triple that of the ML treatment. None of the dogs, regardless of the treatments applied, responded to skin clamping. Conclusion and clinical relevance Cardiovascular parameters do not seem to reflect the occurrence of adverse reactions during rhinoscopy. The maxillary nerve block is superior to the infraorbital nerve block, as applied in this study, in preventing adverse reactions during posterior rhinoscopy.

Objective—To document complications associated with preanesthetic and anesthetic agents used in Vietnamese potbellied pigs and identify predictors of complications. Design—Retrospective case series. Animals—27 potbellied pigs (14 female and 13 male) ranging in age from 0.25 to 15 years old and ranging in body weight from 5.9 to 169 kg (13.0 to 371.8 lb) that were anesthetized on 32 occasions between 1999 and 2006. Procedures—Data, including perianesthetic management, anesthetic agents and dosages, complications, and outcome, were retrieved from medical records. Patient information, anesthetic agents, and duration of anesthesia were evaluated as predictors for development of complications. Results—Anesthesia was maintained with isoflurane or sevoflurane during 30 anesthetic episodes. Commonly used premedicants were butorphanol, atropine, and midazolam administered in combination with xylazine or medetomidine and a combination of tiletamine-zolazepam and butorphanol. Anesthesia was induced with an inhalation agent on 15 occasions, via injection of ketamine on 10 occasions, and via injection of propofol on 3 occasions. Complications included hypoventilation (16/24 [67%]), hypotension (16/25 [64%]), hypothermia (15/31 [48%]), bradycardia (9/32 [28%]), and prolonged recovery time (7/32 [22%]). None of the factors evaluated were associated with development of these complications. All pigs survived anesthesia. Conclusions and Clinical Relevance—Results suggested that a variety of anesthetic agent combinations can be used to provide anesthesia in potbellied pigs with satisfactory outcomes. Although there were high incidences of hypoventilation, hypotension, and hypothermia, no specific anesthetic agent was associated with development of these complications.

To compare the physiological parameters, arterial blood gas values, induction quality, and recovery quality after IV injection of alfaxalone or propofol in dogs.Prospective, randomized, blinded crossover.Eight random-source adult female mixed-breed dogs weighing 18.7 ± 4.5 kg.Dogs were assigned to receive up to 8 mg kg(-1) propofol or 4 mg kg(-1) alfaxalone, administered to effect, at 10% of the calculated dose every 10 seconds. They then received the alternate drug after a 6-day washout. Temperature, pulse rate, respiratory rate, direct blood pressure, and arterial blood gases were measured before induction, immediately post-induction, and at 5-minute intervals until extubation. Quality of induction, recovery, and ataxia were scored by a single blinded investigator. Duration of anesthesia and recovery, and adverse events were recorded.The mean doses required for induction were 2.6 ± 0.4 mg kg(-1) alfaxalone and 5.2 ± 0.8 mg kg(-1) propofol. After alfaxalone, temperature, respiration, and pH were significantly lower, and PaCO2 significantly higher post-induction compared to baseline (p0.03). After propofol, pH, PaO2 , and SaO2 were significantly lower, and PaCO2 , HCO3 , and PA-aO2 gradient significantly higher post-induction compared to baseline (p0.03). Post-induction and 5-minute physiologic and blood gas values were not significantly different between alfaxalone and propofol. Alfaxalone resulted in significantly longer times to achieve sternal recumbency (p = 0.0003) and standing (p = 0.0004) compared to propofol. Subjective scores for induction, recovery, and ataxia were not significantly different between treatments; however, dogs undergoing alfaxalone anesthesia were more likely to have ≥ 1 adverse event (p = 0.041). There were no serious adverse events in either treatment.There were no clinically significant differences in cardiopulmonary effects between propofol and alfaxalone. A single bolus of propofol resulted in shorter recovery times and fewer adverse events than a single bolus of alfaxalone.

Objective To investigate the impact of a change in body position on blood gases and arterial blood pressures in foals anesthetized with guaifenesin, ketamine, and xylazine. Study design Prospective, randomized experimental study. Animals Twelve Quarter Horse foals, age of 5.4 ±0.9 months and weighing 222 ± 48 kg. Methods Foals were anesthetized with guaifenesin, ketamine, and xylazine for 40 minutes in lateral recumbency and then assigned to a change in lateral recumbency after hoisting (Group 1, n = 6), or no change (Group 2, n = 6). Oxygen 15 L minute−1 was insufflated into the endotracheal tube throughout anesthesia. Arterial blood pressure, heart rate, respiratory rate (fR), inspired fraction of oxygen (F i O2), and end-tidal carbon dioxide (P e’ CO2) were measured every 5 minutes. Arterial pH and blood gases [arterial partial pressure of oxygen (PaO2), arterial partial pressure of carbon dioxide (PaCO2)] were measured at 10, 30, and 40 minutes after induction, and 5 minutes after hoisting. Alveolar dead space ventilation and PaO2/F i O2 were calculated. Two repeated measures models were used. All hypothesis tests were two-sided and significance level was α = 0.05. All values are presented as least square means ± SE. Results Values at time-matched points from the two groups were not significantly different so they were combined. Arterial partial pressure of oxygen decreased significantly from 149 ± 14.4 mmHg before hoisting to 92 ± 11.6 mmHg after hoisting (p=0.0013). The PaO2/F i O2 ratio decreased from 275 ± 30 to 175 ± 24 (p=0.0055). End-tidal carbon dioxide decreased significantly from 48.7 ± 1.6 to 44.5 ± 1.2 mmHg (p=0.021). Arterial partial pressure of carbon dioxide, blood pressures and heart rates measured 5 minutes after hoisting were not different from measurements obtained before hoisting. Conclusion and clinical relevance Hoisting decreased PaO2 in anesthetized healthy foals. Administration of supplemental oxygen is recommended to counter the decrease in oxygenation and PaO2 measurement is necessary to detect early changes.

Objective To determine the effects of propofol or etomidate on induction quality, arterial blood pressure, blood gases, and recovery quality in normal dogs. Study design Randomized, blinded trial. Animals Eighteen purpose-bred adult Beagles. Methods Dogs were randomly assigned to receive propofol at 8 mg kg −1 or etomidate at 4 mg kg −1 intravenously (IV) administered to effect. Midazolam was administered at 0.3 mg kg −1 IV as pre-medication at least 1 minute prior to induction. Direct arterial blood pressure, arterial blood gases, and heart rate were obtained at baseline, before induction, after induction, and for every 5 minutes afterwards until the dog began to swallow and the trachea was extubated. The dogs were allowed to breathe room air with the endotracheal tube in place. Results The systolic arterial pressure (SAP) was higher in the etomidate group compared with the propofol group after induction. The SAP and mean arterial pressure (MAP) were higher in the etomidate group compared with the propofol group at 5 minutes. The recovery quality and ataxia score were worse in the etomidate group compared with the propofol group. Time from extubation to sternal recumbency and sternal recumbency to standing was longer in the etomidate group compared with the propofol group. The heart rate, PaCO 2 , and HCO 3 were higher in the propofol group compared with the etomidate group after induction. The PaO 2 and SaO 2 were lower in the propofol group compared with the etomidate group after induction. The SAP and MAP were lower in the propofol group at 5 minutes compared with baseline. Conclusion and clinical relevance Propofol caused a decrease in SAP and MAP which was not observed with etomidate. Etomidate caused longer and poorer recoveries than propofol.

Objective To determine the effects of propofol or thiopental induction on intraocular pressures (IOP) in normal dogs. Study design Prospective randomized experimental study. Animals Twenty-two random-source dogs weighing 19.5 ± 5.3 kg. Methods Dogs were randomly assigned to receive propofol 8 mg kg−1 IV (group P) or thiopental 18 mg kg−1 IV (group T) until loss of jaw tone. Direct arterial blood pressure, arterial blood gasses, and IOP were measured at baseline, after pre-oxygenation but before induction, before endotracheal intubation, and after intubation. Results There were no significant differences between groups with regard to weight, body condition score, breed group, or baseline or before-induction IOP, arterial blood pressure, or blood gases. The baseline IOP was 12.9 mmHg. Before endotracheal intubation, IOP was significantly higher compared to baseline and before induction in dogs receiving propofol. After intubation with propofol, IOP was significantly higher compared to thiopental and was significantly higher compared to before induction. After intubation, IOP was significantly lower compared to before intubation in dogs receiving thiopental. Propofol increased IOP before intubation by 26% over the before-induction score and thiopental increased IOP by 6% at the same interval. The IOP in group P remained 24% over the before induction score whereas thiopental ultimately decreased IOP 9% below baseline after intubation. There was no significant relationship between any cardiovascular or blood gas parameter and IOP at any time. There was no significant relationship between the changes in any cardiovascular or blood gas parameter and the changes in IOP between time points. Conclusions and clinical relevance Propofol caused a significant increase in IOP compared to baseline and thiopental. Thiopental caused an insignificant increase in IOP which decreased after intubation. Propofol should be avoided when possible in induction of anesthesia in animals where a moderate increase in IOP could be harmful.