Ventricular bigeminy associated with myocardial ischemia in a dog with a colonic torsion: a case report.

BACKGROUND: Ventricular bigeminy due to myocardial ischemia has been reported in humans as well as in canine patients with obstructive gastrointestinal diseases. This is the first case report of ventricular bigeminy in a dog with a colonic torsion that resolved after fluid resuscitation and restoration of myocardial perfusion. CASE PRESENTATION: An 11-year-old, male neutered mixed breed dog presented with a one day history of vomiting, tenesmus, and lethargy. Physical examination identified an irregular heart rhythm and intermittent pulse deficits. A ventricular arrhythmia represented by ventricular premature complexes (VPCs) organized in bigeminy, was appreciated on a 3-lead electrocardiogram (ECG) with a single lead (II) view. Abdominal radiographs confirmed a colonic torsion. Prior to anesthetic induction, ventricular bigeminy was non responsive to fentanyl or lidocaine. The patient was anesthetized and intravascular volume deficit was identified by dampened plethysmographic wave amplitude (plethysomographic variability), audible softening of the Doppler sound, and more pronounced pulse deficits. Fluid resuscitation was achieved with a combination of intravenous crystalloid and colloid fluid therapy comprising 7.2% hypertonic saline and 6% hetastarch. The patient's cardiac rhythm converted to normal sinus after fluid resuscitation. The colonic torsion was surgically corrected. The patient recovered well from anesthesia and was ultimately discharged from the hospital 5 days later. CONCLUSIONS: The present case report highlights that myocardial ischemia can lead to ventricular arrythmias, such as ventricular bigeminy. This is the first documented case of ventricular bigeminy in the canine patient with a colonic torsion. Assessment of patient volume status and appropriate fluid resuscitation along with continuous electrocardiogram (ECG) monitoring are vital to patient stability under general anesthesia.

Antinociceptive effects of bupivacaine injected within the internal abdominis rectus sheath in standing healthy horses.

OBJECTIVE: To evaluate a regional anesthetic technique for blocking the abdominal midline in horses. STUDY DESIGN: Anatomical description and prospective, crossover, placebo-controlled, blinded study. ANIMALS: Adult horses; two cadavers, six healthy animals. METHODS: In stage 1, 0.5% methylene blue with 0.25% bupivacaine (0.5 mL kg-1) was injected using ultrasonography into the internal rectus abdominis sheath (RAS) of two cadavers with a one-point or two-point technique. The dye spread was described after the dissection of the abdomens. In stage 2, each horse was injected with 1 mL kg-1 of 0.9% NaCl (treatment PT) or 0.2% bupivacaine (treatment BT) using a two-point technique. The abdominal midline mechanical nociceptive threshold (MNT) was measured with a 1 mm blunted probe tip and results analyzed with mixed-effect anova. Signs of pelvic limb weakness were recorded. RESULTS: The cadaver dissections showed staining of the ventral branches from the eleventh thoracic (T11) to the second lumbar (L2) nerve with the one-point technique and T9-L2 with the two-point technique. Baseline MNTs were, mean ± standard deviation, 12.6 ± 1.6 N and 12.4 ± 2.4 N in treatments PT and BT, respectively. MNT increased to 18.9 ± 5.8 N (p = 0.010) at 30 minutes, and MNT was between 9.4 ± 2.0 and 15.3 ± 3.4 N from 1 to 8 hours (p > 0.521) in treatment PT. MNTs in treatment BT were 21.1 ± 5.9 to 25.0 ± 0.1 N from 30 minutes to 8 hours (p < 0.001). MNTs after the RAS injections were higher in treatment BT than PT (p = 0.007). No pelvic limb weakness was observed. CONCLUSIONS AND CLINICAL RELEVANCE: Antinociception of at least 8 hours without pelvic limb weakness was observed in the abdominal midline in standing horses after the RAS block. Further investigations are necessary to evaluate suitability for ventral celiotomies.

Comparison of Traditional Lecture-Based Learning versus Interactive Electronic Book Learning in Veterinary Student Comprehension of Inhalant Anesthetic Administration, Uptake, and Elimination.

The administration, uptake, and elimination of inhalant anesthetics is a challenging topic in the veterinary curriculum, and lecture-based learning is often insufficient to ensure that students understand these concepts. We hypothesized that the use of an interactive electronic book (e-book) would enhance student comprehension of the material. Two sequential Doctorate of Veterinary Medicine student cohorts participated in a prospective controlled study. The first cohort received traditional lecture-based learning while the second cohort was taught the topic using an interactive e-book. Student comprehension of the material was assessed twice during the course via multiple-choice questions: five questions in a midcourse quiz and seven within the final exam. At the end of the course, students also completed a Likert survey assessing their confidence regarding the topic. Averaged across assessment types, students taught using the interactive e-book scored higher than those taught via the traditional method (p < .001). Final exam scores were significantly higher in the e-book cohort compared with the lecture-based cohort (p < .001). However, there was no difference in quiz scores between groups (p = .109). No significant difference was found between groups in responses to the Likert survey. In conclusion, students using the interactive e-book had better comprehension of the material than students in the traditional lecture group as measured by their scores on multiple-choice question assessments. Future studies are needed to determine whether this advantage persists later in the curriculum when students apply these concepts in the clinical year.

Comparison of hydromorphone and butorphanol for management of pain in equine patients undergoing elective arthroscopy: a randomized clinical trial.

OBJECTIVE: To compare the effects of hydromorphone and butorphanol in horses undergoing arthroscopy and describe the pharmacokinetics of hydromorphone in anesthetized horses. STUDY DESIGN: Randomized controlled clinical trial. ANIMALS: A total of 40 adult horses admitted for elective arthroscopy. METHODS: Horses were randomly assigned to be administered intravenous hydromorphone (0.04 mg kg-1; group TxH; n = 19) or butorphanol (0.02 mg kg-1; group TxB; n = 21) prior to surgery as part of a standardized anesthetic protocol. Pain was scored by two observers unaware of group assignment using the Equine Utrecht University Scale for Facial Assessment of Pain (EQUUS-FAP) and a composite pain scale (CPS) prior to surgery (baseline), 2 hours (P2) and 4 hours (P4) following recovery from anesthesia. Blood samples were collected at various time points for determination of plasma hydromorphone concentration using liquid chromatography-tandem mass spectrometry. Data were analyzed with a mixed-effect model. RESULTS: Median (range) baseline EQUUS-FAP was 1.2 (0.0-4.0) with no effect of group, time points or interaction. Baseline CPS was similar between groups. Group TxH baseline CPS was 2.5 (0.0-10.0), increased at P2 [4.5 (0-10.0); p = 0.046] and returned to baseline values at P4 [3.0 (0.0-11.0)]. Group TxB baseline CPS was 2.0 (0.0-8.0), increased at P2 [3.5 (0.0-11.0); p = 0.009] and P4 [5.0 (0.0-11.0); p < 0.001]. Pharmacokinetic terminal half-life was 774 ± 82.3 minutes, area under the curve was 1362 ± 314 ng minutes mL-1, clearance was 30.7 ± 7.23 mL minute-1 kg-1 and volume of distribution at steady state was 884 ± 740 mL kg-1. CONCLUSIONS: Hydromorphone, but not butorphanol, decreased CPS back to baseline at P4 after recovery. CLINICAL RELEVANCE: Hydromorphone may provide superior postoperative analgesia compared with butorphanol in horses undergoing arthroscopy.

Influence of doxapram and intermittent 10% carbon dioxide inspiration on cardiovascular and laryngeal functions in anesthetized dogs.

OBJECTIVE: To compare the effects of two doses of doxapram intravenous injection and carbon dioxide inhalation on the cardiovascular and laryngeal functions of anesthetized hounds. STUDY DESIGN: Experimental study. ANIMALS: Six healthy adult dogs. METHODS: In a Latin-square design, the mean arterial blood pressure (MABP) and heart rate (HR) were recorded continuously. The inspiratory normalized glottic gap areas (iNGGA) were measured before and after each stimulation with 0.55 mg/kg of doxapram (L-DOX), 2.2 mg/kg of doxapram (H-DOX), or 90 s of inhalation of 10% carbon dioxide in oxygen (I-CO2 ). The stimulations were tested in duplicate or triplicate. Video clips of the laryngeal movement were scored by board-certified surgeons masked to the treatment. RESULTS: The MABP increased with L-DOX and H-DOX up to 81% (both p < .001 compared to I-CO2 ), and persisted during the other stimulations (both p < .001). An intermittent tachycardic effect of up to 79% increase in HR was observed with doxapram. The HR following H-DOX was higher than L-DOX and I-CO2 (both p < .016). Neither hypertension nor tachycardia was observed with I-CO2 . The iNGGA increased with all treatments (p < .001). The iNGGA was greater with H-DOX than L-DOX and I-CO2 (both p < .007). All treatments received higher scores (all p < .001) with acceptable inter- and intra-observers Krippendorff's alphas. CONCLUSION: All treatments were effective respiratory stimulants in anesthetized dogs; however, doxapram caused hypertension and tachycardia. CLINICAL SIGNIFICANCE: Carbon dioxide inhalation might improve arytenoid motion without cardiovascular effects in dogs during clinical airway examinations.

Pharmacokinetics and pharmacodynamics of meperidine after intramuscular and subcutaneous administration in horses.

OBJECTIVE: To describe the pharmacokinetics and pharmacodynamics of meperidine after IM and subcutaneous administration in horses. STUDY DESIGN: prospective, randomized, blinded, crossover trial. ANIMALS: Six adult horses weighing 494 ± 33 kg. METHODS: Treatments included meperidine 1 mg/kg IM with saline 6 mL subcutaneously, meperidine 1 mg/kg subcutaneously with saline 6 mL IM, and saline 6 mL subcutaneously and 6 mL IM, with a 7-day washout between treatments. Plasma meperidine concentrations and pharmacodynamic values (thermal and mechanical thresholds, physiological variables, fecal production) were collected at various time points for 24 hours. Accelerometry data were obtained for 8 hours to measure locomotor activity. Data were analyzed with a mixed effects model, and α was set at .05. RESULTS: Meperidine terminal half-life (T1/2 ), maximal plasma concentrations, and time to maximal concentration were 186 ± 59 and 164 ± 56 minutes, 265.7 ± 47.2 and 243.1 ± 80.1 ng/mL at 17 ± 6, and 24 ± 13 minutes for IM at subcutaneous administration, respectively. No effect of treatment or time was observed on thermal or mechanical thresholds, heart rate, respiratory rate, locomotor activity, frequency of defecations, or fecal weight (P > .2 for all). CONCLUSION: Maximum meperidine concentrations were achieved quickly with a short T1/2 in both treatment groups. Neither IM nor subcutaneous meperidine influenced thermal or mechanical threshold or physiological variables. CLINICAL SIGNIFICANCE: The short half-life and lack of detectable antinociceptive effect do not support IM or subcutaneous administration meperidine at 1 mg/kg for analgesia in horses.

Physiologic and blood gas effects of xylazine-ketamine versus xylazine-tiletamine-zolazepam immobilization of white-tailed deer before and after oxygen supplementation: a preliminary study.

OBJECTIVE: To compare oxygenation and ventilation in white-tailed deer (Odocoileus virginianus) anesthetized with two treatments with and without oxygen supplementation. STUDY DESIGN: Randomized, blinded, crossover study. ANIMALS: A total of eight healthy adult white-tailed deer weighing 49-62 kg. METHODS: Each deer was anesthetized twice intramuscularly: 1) treatment XK, xylazine (2 mg kg-1) and ketamine (6 mg kg-1) and 2) treatment XTZ, xylazine (2 mg kg-1) and tiletamine-zolazepam (4 mg kg-1). With the deer in sternal position, arterial and venous blood was collected before and at 30 minutes during administration of oxygen at 1 L minute-1 through a face mask. PaO2 and heart rate (HR) were compared using two-way repeated measures anova. pH, PaCO2 and lactate concentration were analyzed using mixed-effects linear models, p < 0.05. RESULTS: When breathing air, PaO2 was < 80 mmHg (10.7 kPa) in six and seven deer with XK and XTZ, respectively, and of these, PaO2 was < 60 mmHg (8.0 kPa) in three and five deer, respectively. With oxygen supplementation, PaO2 increased to 128 ± 4 and 140 ± 5 mmHg (17.1 ± 0.5 and 18.7 ± 0.7 kPa), mean ± standard error, with XK and XTZ, respectively (p < 0.001). PaO2 was not significantly different between treatments at either time point. HR decreased during oxygen supplementation in both treatments (p < 0.001). Lactate was significantly lower (p = 0.047) with XTZ than with XK (2.2 ± 0.6 versus 3.5 ± 0.6 mmol L-1) and decreased (p < 0.001) with oxygen supplementation (4.1 ± 0.6 versus 1.6 ± 0.6 mmol L-1). PaCO2 increased in XTZ during oxygen breathing. CONCLUSIONS AND CLINICAL RELEVANCE: Treatments XK and XTZ resulted in hypoxemia, which responded to oxygen supplementation. Both treatments are suitable for immobilization of white-tailed deer under the study circumstances.

ISOFLURANE RESPIRATORY ANESTHETIC INDEX IN CHICKENS (GALLUS GALLUS DOMESTICUS).

Respiratory depression from isoflurane seems to be greater in birds than in mammals. Isoflurane respiratory anesthetic index (AI) has only been evaluated in ducks (Anas platyrhynchos), which indeed showed a lower AI compared to mammals, but the isoflurane AI for other avian species is not known. The aim of this study was to evaluate the isoflurane AI in chickens (Gallus gallus domesticus). Six adult hens were anesthetized with isoflurane for determination of the minimum anesthetic concentration (MAC) using the bracketing method. During a second anesthetic event, the isoflurane AI was determined by progressively increasing the expired fraction of isoflurane by 0.5 times MAC until apnea was achieved (ETiso-apnea). The isoflurane AI was considered the ratio between the ETiso-apnea and the MAC. Heart rate, systolic arterial pressure, respiratory rate, and end-tidal carbon dioxide were continuously monitored throughout both anesthetic events. Data were analyzed using a mixed-effect model with Greenhouse-Geisser correction, followed by Tukey's test. The MAC for isoflurane was 1.18% ± 0.09% (mean ± SD). The ETiso-apnea was 3.31% ± 0.34% and the isoflurane AI was 2.80 ± 0.26. In chickens, isoflurane AI is similar to that measured in mammals, which is in contrast with published data in other avian species.

A retrospective evaluation of the effect of perianesthetic hydromorphone administration on the incidence of postanesthetic signs of colic in horses.

OBJECTIVE: To describe the incidence of postanesthetic signs of colic (PASC) in horses and determine if perianesthetic administration of hydromorphone was associated with an increased risk of PASC. STUDY DESIGN: Retrospective, cohort study. ANIMALS: A total of 409 horses. METHODS: Anesthesia and clinical records of horses admitted for various procedures from July 2018 to September 2019 were reviewed. Signs of colic and interventions were recorded up to 48 hours after anesthesia. A binomial logistic regression model was used to evaluate the association between the type of surgery, administration of hydromorphone, the duration of anesthesia and the incidence of PASC. RESULTS: Overall, 25 (6.1%) horses developed PASC within 48 hours of general anesthesia. Of 60 horses that underwent colic surgery, 16 (26.7%) developed PASC. Of 349 horses that underwent noncolic procedures, nine (2.6%) developed PASC. Thus, the incidence of PASC was higher in horses that underwent colic surgery than in horses that underwent noncolic procedures [odds ratio (OR) = 13.74 (5.73-32.95)]. No effect of hydromorphone on the incidence of PASC was identified [OR = 1.61 (0.71-3.62)]. Longer procedures (>2 hours) were identified as an independent risk factor for PASC [OR = 4.13 (1.52-11.22)]. CONCLUSIONS: No association between hydromorphone and an increase in the incidence of PASC was identified. Anesthesia for colic surgery and duration of anesthesia were associated with an increased risk of PASC. CLINICAL RELEVANCE: Hydromorphone did not increase the incidence of PASC in this population.

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

OBJECTIVE: To compare the pharmacokinetics and pharmacodynamics of hydromorphone in horses after intravenous (IV) and intramuscular (IM) administration. STUDY DESIGN: Randomized, masked, crossover design. ANIMALS: A total of six adult horses weighing [mean ± standard deviation (SD))] 447 ± 61 kg. METHODS: Horses were administered three treatments with a 7 day washout. Treatments were hydromorphone 0.04 mg kg⁻1 IV with saline administered IM (H-IV), hydromorphone 0.04 mg kg⁻1 IM with saline IV (H-IM), or saline IV and IM (P). Blood was collected for hydromorphone plasma concentration at multiple time points for 24 hours after treatments. Pharmacodynamic data were collected for 24 hours after treatments. Variables included thermal nociceptive threshold, heart rate (HR), respiratory frequency (fR), rectal temperature, and fecal weight. Data were analyzed using mixed-effects linear models. A p value of less than 0.05 was considered statistically significant. RESULTS: The mean ± SD hydromorphone terminal half-life (t1/2), clearance and volume of distribution of H-IV were 19 ± 8 minutes, 79 ± 12.9 mL minute⁻1 kg⁻1 and 1125 ± 309 mL kg⁻1. The t1/2 was 26.7 ± 9.25 minutes for H-IM. Area under the curve was 518 ± 87.5 and 1128 ± 810 minute ng mL⁻1 for H-IV and H-IM, respectively. The IM bioavailability was 217%. The overall thermal thresholds for both H-IV and H-IM were significantly greater than P (p < 0.0001 for both) and baseline (p = 0.006). There was no difference in thermal threshold between H-IV and H-IM. No difference was found in physical examination variables among groups or in comparison to baseline. Fecal weight was significantly less than P for H-IV and H-IM (p = 0.02). CONCLUSIONS AND CLINICAL RELEVANCE: IM hydromorphone has high bioavailability and provides a similar degree of antinociception to IV administration. IM hydromorphone in horses provides a similar degree and duration of antinociception to IV administration.

Effect of propofol and ketamine-diazepam on intraocular pressure in healthy premedicated dogs.

OBJECTIVE: To compare the effect of propofol and ketamine/diazepam for induction following premedication on intraocular pressure (IOP) in healthy dogs. STUDY DESIGN: Prospective, quasi-experimental, unmasked, longitudinal. ANIMALS: A total of 61 client-owned dogs. METHODS: Dogs were anesthetized twice with a 4 week washout period. Premedication with dexmedetomidine (5 µg kg-1) and hydromorphone (0.1 mg kg-1) intramuscularly was followed by either propofol (4 mg kg-1) or ketamine (5 mg kg-1) and diazepam (0.25 mg kg-1) intravenously for induction and inhaled isoflurane for maintenance. IOP was measured by applanation tonometry using TonoPen-XL before premedication and after 5, 10, 20 and 30 minutes. IOP was measured again immediately after induction and after 3, 5, 10, 15, 20, 30 and 40 minutes. Data were analyzed using one- or two-way repeated measures ANOVA. RESULTS: No difference was found between right and left IOP (p = 0.45), and data from both the eyes of each dog were averaged and considered as one set of data. Following premedication, IOP was significantly lower at all time points than at baseline when animals were grouped together, mean difference -1.6 ± 0.2 mmHg (p < 0.05). IOP increased immediately (12.2 ± 2.4 mmHg before versus 17.1 ± 3.8 mmHg after) and at 3, 5 (p < 0.001), 10 and 40 minutes (p = 0.009 and 0.045, respectively) after propofol administration. For ketamine/diazepam, IOP was increased immediately post-induction (13.0 ± 2.7 mmHg before versus 14.7 ± 2.8 mmHg after) and at 3, 5 (p < 0.001), 30 and 40 minutes (p = 0.010 and 0.037, respectively). CONCLUSIONS AND CLINICAL RELEVANCE: Sedation with hydromorphone and dexmedetomidine significantly decreased IOP in normal dogs and may be an appropriate choice for dogs that cannot tolerate acute increases in IOP. However, IOP increased significantly after both induction protocols, abolishing the effect of premedication.

The pharmacokinetics and pharmacodynamics of intravenous hydromorphone in horses.

OBJECTIVE: Describe the pharmacokinetics and pharmacodynamics of intravenous hydromorphone in healthy horses. STUDY DESIGN: Masked, randomized, cross-over, Latin square design. ANIMALS: A group of eight healthy adult horses METHODS: Horses were administered each of four treatments with an 8 day washout. Treatments groups included intravenous hydromorphone 0.02 mg kg-1 (LD), 0.04 mg kg-1 (MD), 0.08 mg kg-1 (HD) and saline (P). Blood samples for hydromorphone analysis were obtained for 24 hours after treatment. Plasma hydromorphone was quantified and pharmacokinetic parameters were determined using non-compartmental analysis. Pharmacodynamic data collected for 24 hours after treatment included thermal nociceptive threshold, heart rate (HR), respiratory rate (fR) and rectal temperature, and analyzed using mixed-effects linear models. RESULTS: Mean (± standard deviation) hydromorphone terminal half-life (t1/2), systemic clearance and apparent volume of distribution at steady state (Vdss) were 18.1 ± 18.6, 34.0 ± 12.8, and 41.3 ± 32.5 minutes, 66.6 ± 5.3, 550.0 ± 76.4, and 92.7 ± 13.9 mL kg-1 minute-1, and 1118 ± 369, 1460 ± 325 and 2242 ± 950 mL kg-1 for treatments LD, MD and HD, respectively. Thermal threshold increased significantly compared to baseline for all treatments for up to 12 hours. HR was elevated above baseline in treatments LD, MD and HD, extending to 30, 15 and 105 minutes after treatment, respectively. Respiratory rate was elevated above baseline in treatments MD and HD from 30 to 195 minutes and from 45 to 480 minutes after treatment, respectively. Temperature was elevated above baseline in treatment HD until 255 minutes after treatment. CONCLUSIONS: Hydromorphone exhibited a short t1/2, rapid clearance and large Vdss in horses. It also provided a dose-dependent increase in thermal threshold with associated increases in HR, fR and rectal temperature. CLINICAL RELEVANCE: Hydromorphone 0.04 mg kg-1 provided clinically relevant thermal antinociception with minimal adverse effects.

Critical incident technique analysis applied to perianesthetic cardiac arrests at a university teaching hospital.

OBJECTIVE: To apply the critical incident technique (CIT) methodology to a series of perianesthetic cardiac arrest events at a university teaching hospital to describe the factors that contributed to cardiac arrest. STUDY DESIGN: CIT qualitative analysis of a case series. ANIMALS: A group of 16 dogs and cats that suffered a perioperative cardiac arrest between November 2013 and November 2016. METHODS: If an arrest occurred, the event was discussed among the anesthesiologists. The discussion included a description of the case, a description of the sequence of events leading up to the arrest and a discussion of what could have been done to affect the outcome. A written description of the case and the event including animal signalment and a timeline of events was provided by the supervising anesthesiologist following discussion among the anesthesiologists. Only dogs or cats were included. After the data collection period, information from the medical record was collected. A qualitative document analysis was performed on the summaries provided about each case by the supervising anesthesiologist, the medical record and any supporting documents. Each case was then classified into one or more of the following: animal, human, equipment, drug and procedural factors for cardiac arrest. RESULTS: The most common factor was animal (n=14), followed by human (n=12), procedural (n=4), drugs (n=1) and equipment (n=1). The majority (n=11) of animals had multiple factors identified. CONCLUSIONS AND CLINICAL RELEVANCE: Cardiac arrests during anesthesia at a referral teaching hospital were primarily a result of animal and human factors. Arrests because of procedural, drug and equipment factors were uncommon. Most animals experienced more than one factor and two animals arrested after a change in recumbency. Future work should focus on root cause analysis and interventions designed to minimize all factors, particularly human ones.

Agreement among anesthesiologists regarding postoperative pain assessment in dogs.

OBJECTIVE: To establish evidence for the validity and reliability of three commonly used pain scales in dogs when assessed by video by specialists in anesthesia. STUDY DESIGN: Mixed-method test-retest observational study. SUBJECTS: A group of six American College of Veterinary Anesthesia and Analgesia board-certified specialists and 31 postoperative dogs. METHODS: The evaluators scored 31 dogs using a visual analogue scale (VAS), numeric rating scale (NRS), and Glasgow pain scale (GPS). The evaluators individually scored the dogs using all three scales together and subsequently, at 3 month intervals, using each of the scales apart. Then, all evaluators in one room reviewed 23 of the videos. A camera was positioned for video and audio recording of discussion about the videos. Intra- and interobserver reliability was determined using a two-way random model intra-class correlation coefficient (ICC). RESULTS: Linear regression indicated a strong correlation among all scales when assigned together (VAS versus NRS, p < 0.0001, R2 = 0.93; VAS versus GPS, p < 0.0001, R2 = 0.59; and NRS versus GPS, p < 0.0001, R2 = 0.61) and apart (VAS versus NRS, p < 0.0001, R2 = 0.68; VAS versus GPS, p < 0.0001, R2 = 0.40; and NRS versus GPS, p < 0.0001, R2 = 0.47). Posture, appearance, vocalization, stiffness, interaction between the animal and a person and response to palpation were identified as important variables for assessing pain. Intra-observer reliability produced average ICC values of 0.90 for VAS, 0.89 for NRS and 0.85 for GPS. Interobserver reliability produced average ICC values when scores were assigned together (VAS: 0.93, NRS: 0.93 and GPS: 0.93) and when done separately (VAS: 0.91, NRS: 0.93 and GPS: 0.95). CONCLUSIONS AND CLINICAL RELEVANCE: The preferred use of the VAS and NRS over the use of the GPS should be cautiously considered for research applications when experts are observers. Revisions of the GPS to clarify descriptors and remove or modify items that may not be associated with pain in dogs should be considered.

Effect of routine pre-anesthetic laboratory screening on pre-operative anesthesia-related decision-making in healthy dogs.

The usefulness of pre-anesthetic laboratory screening of healthy veterinary patients is controversial and clear evidence-based guidelines do not exist. The purpose of our study was to determine the influence of preanesthetic laboratory screening on peri-anesthetic plans in canine patients undergoing elective surgery. One hundred medical records were randomly selected between the years 2008 and 2013 and patient information was presented to 5 Diplomates of the American College of Veterinary Anesthesia and Analgesia (ACVAA) for review. They were given pre-anesthetic laboratory screening test results for each patient and asked whether the results would change the way they managed the case from an anesthesia perspective. Peri-operative anesthetic management was altered in 79% of patients based on pre-anesthetic screening results; however, the overall agreement among anesthesiologists was weak with 64% of changes made by only a single anesthesiologist. Pre-anesthetic laboratory screening test results may influence pre-operative anesthesia case management but major discrepancies can occur among ACVAA diplomates.

Effet du dépistage de laboratoire pré-anesthésique de routine sur la prise de décisions préopératoires liées à l'anesthésie chez des chiens en santé. L'utilité du dépistage de laboratoire pré-anesthésique des patients vétérinaires en santé est controversée et des lignes directrices claires basées sur des données probantes n'existent pas. Le but de notre étude consistait à déterminer l'influence du dépistage de laboratoire pré-anesthésique pour la péri-anesthésie chez les patients canins subissant une chirurgie non urgente. Cent dossiers médicaux choisis au hasard entre les années 2008 et 2013 et des données sur les patients ont été présentés à cinq diplomates de l'American College of Veterinary Anesthesia and Analgesia (ACVAA) aux fins d'examen. On leur a donné les résultats des tests de dépistage de laboratoire pré-anesthésiques pour chaque patient et on leur a demandé d'évaluer si les résultats auraient modifié la façon dont ils auraient géré le cas du point de vue de l'anesthésie. La gestion anesthésique péri-opératoire a été modifiée chez 79 % des patients en se basant sur les résultats du dépistage préanesthésique. Cependant, le consensus général parmi les anesthésiologistes était faible avec 64 % des changements apportés par seulement un seul anesthésiologiste. Les résultats des tests de dépistage de laboratoire pré-anesthésiques peuvent influencer la gestion des cas d'anesthésie préopératoire mais des écarts majeurs peuvent se produire parmi les diplomates de l'ACVAA.(Traduit par Isabelle Vallières).

Retrospective study of intra-anesthetic predictors of prolonged hospitalization, increased cost of care and mortality for canine patients at a veterinary teaching hospital.

OBJECTIVE: To determine the impact of intraoperative anesthetic variables on the length of hospitalization, cost of care and mortality in dogs. STUDY DESIGN: Retrospective, observational study. ANIMALS: A total of 235 dogs undergoing general anesthesia. METHODS: Medical records of dogs undergoing general anesthesia between 2007 and 2014 at the University of Georgia Veterinary Teaching Hospital were reviewed. Data collected included demographic data, American Society of Anesthesiologists (ASA) physical status, type and duration of anesthesia, hemodynamic variables, temperature, ventilation, fluid therapy and adjunctive drugs administered. Outcome variables were length of hospitalization in the intensive care unit (ICU), hospital charges and survival to discharge. RESULTS: The only factor significantly associated with duration of ICU care was higher ASA status (p<0.0001). Factors associated with increased cost of hospitalization were ICU duration (p<0.0001), anesthesia duration (p<0.0001), hemorrhage amount (p<0.0001), colloid use (p=0.0081), increased age (p=0.0253), increased weight (p = 0.0293) and presence of hypertension (p=0.0179). Overall mortality rate was 5.1%. The only factors negatively associated with survival were the administration of colloids (p<0.0008) and ASA status (p=0.0314). CONCLUSIONS AND CLINICAL RELEVANCE: Several intrinsic patient factors and intraoperative hemodynamic variables were significantly associated with postoperative morbidity and mortality in dogs. These factors might have prognostic value in conjunction with preoperative risk assessment, and patient outcome may be improved by stricter intraoperative control of these variables.

Agreement between veterinary students and anesthesiologists regarding postoperative pain assessment in dogs.

OBJECTIVE: To determine the levels of agreement among first- and second-year veterinary students and experienced anesthesiologists in assessing postoperative pain in dogs from video-recordings. STUDY DESIGN: Cross-sectional study. SUBJECTS: Twenty-seven veterinary students, five anesthesiologists and 13 canine clinical patients. METHODS: Prior to their enrolment in a core anesthesia course, veterinary students volunteered to watch 13 90 second videos of dogs. Dogs were hospitalized in an intensive care unit after a variety of surgical procedures. Students were asked to score the level of the dogs' pain using the Dynamic Interactive Visual Analog Scale and the Short Form of the Glasgow Composite-Measure Pain Scale. The same videotapes were scored by five board-certified anesthesiologists. The differences and agreement between the ratings of anesthesiologists and students, and first- and second-year students were determined with Mann-Whitney U-tests and Fleiss' or Cohen's kappa, respectively. RESULTS: Pain scores assigned by students and anesthesiologists differed significantly (p < 0.01). Students assigned higher pain scores to dogs that were given low pain scores by anesthesiologists, and lower pain scores to dogs deemed to be in more pain by anesthesiologists. On average, students assigned higher scores on both scales. CONCLUSIONS AND CLINICAL RELEVANCE: Veterinary students early in their training assigned pain scores to dogs that differed from scores assigned by experienced anesthesiologists.

Behavioral response and cost comparison of manual versus pharmacologic restraint protocols in healthy dogs.

Although sedatives are routinely administered to dogs for diagnostic and minimally invasive procedures, manual restraint is often used. The study compared intra-procedural behavioral response, scored on a 100-point, visual analog scale, and cost of restraint in healthy dogs given 1 of 5 treatments: manual restraint, dexmedetomidine at 125 µg/m(2) (Dex 125) or 375 µg/m(2) (Dex 375), Dex 125 plus butorphanol at 0.4 mg/kg (Dex 125 + Bu), or Dex 375 plus butorphanol at 0.4 mg/kg (Dex 375 + Bu). Mean behavioral response scores in dogs declined from baseline in the manual restraint group and improved in a linear fashion in the group order Dex 125, Dex 375, Dex 125 + Bu, and Dex 375 + Bu. Dexmedetomidine at 375 µg/m(2) or at 125 µg/m(2) or at 375 µg/m(2) in combination with butorphanol produced the best intra-procedural behavioral response. The cost of sedative drugs was offset by the opportunity cost of diverting personnel from revenue-generating activity to manual restraint.

Réaction comportementale et comparaison du coût des protocoles de contention manuelle par rapport aux protocoles de retenue pharmacologiques chez des chiens en santé. Même si des sédatifs sont régulièrement administrés aux chiens pour des procédures diagnostiques ou minimalement invasives, la contention manuelle est souvent utilisée. L'étude a comparé la réaction comportementale durant la procédure, évaluée sur une échelle analogue visuelle de 100 points, et le coût de la retenue chez des chiens en santé auxquels on a administré l'un de 5 traitements : la contetnion manuelle, la dexmédétomidine à 125 µg/m2 (Dex 125) ou à 375 µg/m2 (Dex 375), la Dex 125 et du butorphanol à 0,4 mg/kg (Dex 125 + Bu) ou la Dex 375 et du butorphanol à 0,4 mg/kg (Dex 375 + Bu). Les notes moyennes de réaction comportementale chez les chiens ont chuté de la valeur de base dans le groupe de contention manuelle et elles se sont améliorées de façon linéaire dans l'ordre des groupes Dex 125, Dex 375, Dex 125 + Bu et Dex 375 + Bu. La dexmédétomidine à 375 µg/m2 ou à 125 µg/m2 ou à 375 µg/m2 en combinaison avec du butorphanol a produit la meilleure réaction comportementale pendant la procédure. Le coût des sédatifs a été compensé par le coût découlant de l'affectation du personnel à des activités produisant des revenus au lieu de la contention manuelle.(Traduit par Isabelle Vallières).

Evaluation of serial venous and arterial lactate concentrations in healthy anesthetized sheep undergoing ovariectomy.

OBJECTIVE: To determine if lactate concentrations in jugular venous and auricular arterial blood differ in anesthetized sheep. STUDY DESIGN: Prospective, controlled experimental study. ANIMALS: Twelve healthy adult ewes, 4-7 years and weighing 62-77 kg. METHODS: Jugular venous blood was collected before anesthesia (PreOv ) for measurement of lactate concentration, packed cell volume and total protein. Ewes were administered a standard anesthesia protocol. Jugular venous (IntraOv ) and auricular arterial (IntraOa ) blood samples were obtained 40 minutes after induction of anesthesia, and again in recovery (PostOv and PostOa ). An additional blood sample was drawn 6 weeks post-operatively from non-fasted sheep (NF_Lact). Lactate concentrations were compared among PreOv , IntraOv and IntraOa , PostOv and PostOa , and between PreOv and NF_Lact with paired t-test and repeated measure analyses of variance (anova) with PreOv as a covariate (p ≤ 0.05). RESULTS: IntraOv lactate concentration had decreased from PreOv There were significant differences between arterial and venous IntraO and PostO lactate concentrations. There was no significant difference between IntraO and PostO, or PreOv and NF_Lact. CONCLUSIONS AND CLINICAL RELEVANCE: Lactate concentrations were significantly lower in anesthetized sheep compared to non-anesthetized sheep. Lactate concentrations in venous blood were higher than in arterial blood. Therefore, anesthetic status and sampling site should be considered when interpreting lactate concentrations, and the sampling site should be consistent for repeated measurements.