A Pressure-Based Model of IV Fluid Therapy Kinetics.

The kinetics of intravenous (IV) fluid therapy and how it affects the movement of fluids within humans and animals is an ongoing research topic. Clinical researchers have in the past used a mathematical model adopted from pharmacokinetics that attempts to mimic these kinetics. This linear model is based on the ideas that the body tries to maintain fluid levels in various compartments at some baseline targets and that fluid movement between compartments is driven by differences between the actual volumes and the targets. Here a nonlinear pressure-based model is introduced, where the driving force of fluid movement out of the blood stream is the pressure differences, both hydrostatic and oncotic, between the capillaries and the interstitial space. This model is, like the linear model, a coarse representation of fluid movement on the whole body scale, but, unlike the linear model, it is based on some of the body's biophysical processes. The abilities of both models to fit data from experiments on both awake and anesthetized cats was analyzed. The pressure-based model fit the data better than the linear model in all but one case, and was deemed statistically significantly better in a third of the cases.

Evaluation of the effect of fresh-frozen plasma transfusion on circulating hyaluronic acid concentration in critically ill dogs: a pilot study.

OBJECTIVE: To describe changes in circulating hyaluronic acid (HA) concentration, a biomarker of endothelial glycocalyx degradation, after administration of fresh-frozen plasma (FFP) in critically ill dogs. ANIMALS: 12 client-owned dogs receiving an FFP transfusion due to underlying disease. METHODS: Plasma samples were collected for HA concentration measurement pre-FFP transfusion (T0) and 10 minutes (T10) and 90 minutes (T90) following completion of FFP transfusion of a minimum volume of 7 mL/kg. Hyaluronic acid was also measured in the transfused FFP units following in-house validation of a commercial HA assay on citrate phosphate dextrose-anticoagulated plasma. Potential associations of the difference between pre-FFP and post-FFP HA plasma concentrations with the volume of FFP transfused, the cumulative volume of IV fluids administered during the study period, and the HA concentration in the transfused unit were explored. RESULTS: Concentrations of HA were not significantly different between pre- and post-FFP transfusion measurements. The volume of FFP transfused, the cumulative volume of other IV fluids administered during the study time, and the concentration of HA in the FFP units had no significant effect on the change in HA concentration following FFP transfusion in this study. CLINICAL RELEVANCE: This pilot study did not demonstrate an association between FFP administration and changes in plasma HA concentration. The results of this study may serve to help design future research. A commercial assay was validated to measure HA in citrate phosphate dextrose-anticoagulated plasma.

Clinical methemoglobinemia secondary to administration of hydroxyurea at therapeutic doses in a dog.

Methemoglobinemia secondary to administration of hydroxyurea is only reported in veterinary medicine as a result of accidental ingestion of high doses, and once at therapeutic dose in human medicine. A 2.5-year-old female spayed mixed breed dog was presented for acute signs of neurologic disease and diagnosed with severe erythrocytosis without an identified underlying cause, leading to suspicion of polycythemia vera. The dog was managed with phlebotomies, supportive care, and administration of hydroxyurea. Within 2 h of administration of hydroxyurea (37 mg/kg) administration, respiratory distress with cyanosis, and methemoglobinemia developed. Signs resolved within 24 h but recurred after a second administration of lower dosage of hydroxyurea (17 mg/kg) 20 days later. The dog remained asymptomatic except for mild cyanosis but was humanely euthanized for lack of relevant improvement of signs of neurologic disease. This case report documents the repeated occurrence of methemoglobinemia in a dog after administration of hydroxyurea at therapeutic doses.

Evaluation of a noncontrolled, pre-euthanasia, intramuscular sedation drug protocol including alfaxalone 4%, medetomidine, and acepromazine for injured or ill raccoons.

Background: As a major animal control service provider in the city of Guelph and Wellington County in Ontario, the Guelph Humane Society transports and presents injured or ill raccoons requiring humane euthanasia to the Ontario Veterinary College Health Sciences Centre (OVC-HSC). Issues around handling, transportation, and delays before euthanasia have recently raised some concerns for welfare and the need for means of improving this process. Objective: Investigation of a noncontrolled sedation and analgesia protocol for injured or ill raccoons intended to improve animal welfare by allowing humane handling, transport, and euthanasia following administration by an animal protection officer (APO). Animals and procedure: Twenty-seven injured or ill raccoons requiring transport and euthanasia, as determined by the Guelph Humane Society APOs, were included in the study. Each raccoon was administered acepromazine (0.05 mg/kg), alfaxalone (4 mg/kg), and medetomidine (0.15 mg/kg), intramuscularly, before being transported to the OVC-HSC for humane euthanasia. Results: The combination of acepromazine, alfaxalone, and medetomidine was suitable for administration by APOs and provided the desired sedation depth to allow transport and humane euthanasia. Transit time was the only predictor of sedation depth upon arrival at the OVC-HSC. Two raccoons showed mild physical response to intracardiac injection for euthanasia. Numerical cutoff points of an in-hospital visual analog score of sedation of ≥ 70/100 and duration of sedation of < 62 min showed zero probability of response to euthanasia. Conclusion and clinical relevance: Administration of acepromazine, alfaxalone, and medetomidine at the stated doses provided acceptable sedation and analgesia to improve animal welfare during transport and eventual euthanasia of raccoons.

Évaluation d'un protocole médicamenteux sans groupe témoin de sédation intramusculaire, pré-euthanasie, comprenant de l'alfaxalone 4 %, de la médétomidine et de l'acépromazine pour les ratons laveurs blessés ou malades. Contexte: En tant que fournisseur majeur de services de contrôle des animaux dans la ville de Guelph et dans le comté de Wellington en Ontario, la Guelph Humane Society transporte et présente les ratons laveurs blessés ou malades nécessitant une euthanasie sans cruauté au Ontario Veterinary College Health Sciences Centre (OVC-HSC). Les problèmes liés à la manutention, au transport et aux délais avant l'euthanasie ont récemment soulevé des inquiétudes quant au bien-être et à la nécessité de trouver des moyens d'améliorer ce processus. Objectif: Enquête sur un protocole de sédation et d'analgésie sans groupe témoin pour les ratons laveurs blessés ou malades destiné à améliorer le bien-être des animaux en permettant une manipulation, un transport et une euthanasie sans cruauté après administration par un agent de protection des animaux (APO). Animaux et procédure: Vingt-sept ratons laveurs blessés ou malades nécessitant un transport et une euthanasie, tel que déterminé par les APO de la Guelph Humane Society, ont été inclus dans l'étude. Chaque raton laveur a reçu de l'acépromazine (0,05 mg/kg), de l'alfaxalone (4 mg/kg) et de la médétomidine (0,15 mg/kg), par voie intramusculaire, avant d'être transporté à l'OVC-HSC pour une euthanasie sans cruauté. Résultats: La combinaison d'acépromazine, d'alfaxalone et de médétomidine convenait à l'administration par un APO et fournissait la profondeur de sédation souhaitée pour permettre le transport et l'euthanasie sans cruauté. Le temps de transit était le seul prédicteur de la profondeur de la sédation à l'arrivée à l'OVC-HSC. Deux ratons laveurs ont montré une légère réponse physique à une injection intracardiaque pour l'euthanasie. Les seuils numériques d'un score analogique visuel de sédation à l'hôpital ≥ 70/100 et d'une durée de sédation < 62 min ont montré une probabilité nulle de réponse à l'euthanasie. Conclusion et pertinence clinique: L'administration d'acépromazine, d'alfaxalone et de médétomidine aux doses indiquées a fourni une sédation et une analgésie acceptables pour améliorer le bien-être des animaux pendant le transport et l'euthanasie éventuelle des ratons laveurs.(Traduit par Dr Serge Messier).

Student Veterinarian Perceptions of Community-Based Primary Care Veterinary Clinics in Indigenous Communities in Southern Ontario, Canada.

Community-based primary care veterinary clinics represent an opportunity to benefit multiple populations. Student veterinarians are afforded the opportunity to build technical and non-technical professional skills, while underserved communities are provided with access to companion animal care. The Ontario Veterinary College (OVC), as with many other veterinary colleges across Canada and the United States, has hosted community-based primary care veterinary clinics, including in local Indigenous communities. As these clinics continue and grow, it is critical to evaluate their operation to ensure that they align with community goals and values, adequately support student learning, and do not perpetuate racism and implicit bias. The objective of this study was to explore the perceptions of student veterinarians who had volunteered at community-based primary care veterinary clinics in First Nations communities in southern Ontario, Canada. We used an online survey that consisted of multiple choice and short answer questions focused on motivating factors for involvement, supports available before and during the clinics, exposure to Indigenous cultures, and the challenges and rewards associated with volunteering. Forty-one student veterinarians from OVC completed the survey in January 2020. Most students were motivated to volunteer to make a positive difference in the lives of people and animals and improve their clinical skills. In general, respondents felt adequately prepared for and supported during their experiences but did recommend additional pre-departure instructions on roles and responsibilities. Participants were ambivalent as to whether they had learned about Indigenous culture, with several strongly recommending more cultural sensitivity training. Most students found their experiences rewarding because of the gratitude expressed by clients and the feeling that they had made a difference. We reflect on the potential benefits and challenges of community-based primary care veterinary clinics in light of student responses.

The impact of deferred intake as part of Capacity for Care (C4C) on shelter cat outcomes.

Capacity for Care (C4C) is a shelter management strategy that is capable of improving the welfare of cats in a shelter's care. Managing shelter intake using intake waitlists and scheduled intake appointments is a key feature of C4C. The purpose of this study was to describe the population of owned cats whose owners contacted the Guelph Humane Society (GHS) to explore the option of relinquishing, and to report outcomes for this population. Data were collected retrospectively from shelter records created by the GHS from July 2017 to June 2018. This study further examined associations between cat outcome and rehoming options under consideration by owners at the initial point of contact with the shelter, cat source, and reason for relinquishment. A greater proportion of cats with veterinary issues reported as the primary reason for potential surrender were kept by their owners compared with being relinquished (p<0.01), rehomed (p<0.01), and having an unknown outcome (p<0.01). A greater proportion of cats whose owners had medical issues were surrendered, compared with being retained in their homes.The large number of cats whose outcomes were unknown suggests a need for future research in order to further understand the outcomes that are occurring for cats whose admission to a shelter are deferred.

Shelter Worker's Experiences and Perceptions of Capacity for Care (C4C).

Capacity for Care (C4C) is a shelter management strategy which utilizes managed intake to optimize in-shelter populations based on housing capacity and available resources. The purpose of this study was to 1) understand staff experiences using managed intake, 2) explore staff perceptions of how the C4C model has been regarded by other staff at their facility, and 3) explore the response of community members who are attempting to relinquish their cats, as perceived by the staff who are communicating with cat owners and scheduling relinquishment. Participants recruited from shelters who practiced C4C participated in a semi-structured interview and completed a written survey to share their experiences and perceptions of C4C. Based on the perceptions of the participants, evidence suggests the waitlist may decrease the admission of owned cats to the shelter as a result of advising cat owners about alternatives to relinquishment. The findings suggest that more research is needed to understand the potential impacts of managed intake, as an element of C4C, on the welfare of cats in the community who are waiting to be admitted to a shelter.

Validation of 3-dimensional mathematical computation of feline bladder volume using orthogonal ultrasonographic bladder images.

Urine output measurement is critical for the management of hospitalized cats and their underlying conditions. Ultrasound-guided estimation of urinary bladder volume (UBV) is a non-invasive surrogate measurement that can provide important clinical information. The purpose of this study was to validate the accuracy of a novel 3D computation method in estimating UBV using 2D point-of-care ultrasonographic images. Bladder volume estimation was performed using coordinates from bladder circumference tracings on paired longitudinal and transverse ultrasonographic images (n = 359) aligned in 3D space for mathematical algorithmic computation. Ultrasonographic images were obtained by 2 different observers at 18 different time points on 10 healthy, purpose-bred male cats under general anesthesia in sternal recumbency. Actual urine volumes were measured via urinary catheterization and compared to UBV estimations using Lin's concordance correlation coefficient and Bland-Altman analysis. Estimation of UBV using the 3D computational bladder circumference tracing method showed moderate strength-of-agreement with actual bladder volume (ρc = 0.94 to 0.95) with clinically insignificant bias (3D computation-derived minus actual volume) of -1.96 mL (IQR = -3.89 to -0.57 mL, P < 0.001) and -2.42 mL (IQR = -4.64 to -0.66 mL, P < 0.001) for the 2 observers, respectively. Our study demonstrated acceptable accuracy of 3D computation method for UBV estimation in healthy cats. This method may provide a bridging alternative until 3D ultrasound becomes more readily accessible.

La mesure de la diurèse est critique pour la gestion de chats hospitalisés ainsi que de leurs conditions sous-jacentes. L'estimation échoguidée du volume vésical (UBV) est une mesure de substitution non-invasive qui peut fournir d'importantes informations cliniques. L'objectif de cette étude fut de valider la précision d'une nouvelle méthode de calcul 3D dans l'estimation du volume vésical à l'aide d'images 2D obtenues par échographie au point d'intervention. L'estimation du volume vésical a été réalisée à l'aide de coordonnées des tracés de la circonférence de la vessie sur des images échographiques longitudinales et transversales appariées (n = 359), alignées dans l'espace 3D pour le calcul algorithmique mathématique. Des images échographiques ont été obtenues par deux observateurs différents à 18 moments différents sur 10 chats mâles sains et élevés à cette fin, sous anesthésie générale en décubitus sternal. Les volumes d'urine réels ont été mesurés par cathétérisme urinaire et comparés aux estimations de volume vésical à l'aide du coefficient de corrélation de concordance de Lin et de l'analyse de Bland-Altman. L'estimation du volume vésical à l'aide de la méthode 3D de traçage de la circonférence de la vessie a démontré un degré d'accord modérée avec le volume réel de la vessie (ρc = 0,94 to 0,95) avec un biais cliniquement insignifiant (calcul 3D moins volume réel) de −1,96 mL (écart interquartile = −3,89 à −0,57 mL, P < 0,001) et de −2,42 mL (écart interquartile = −4,64 à −0,66 mL, P < 0,001) pour les deux observateurs respectivement. Notre étude a démontré une précision acceptable de la méthode de calcul 3D pour l'estimation du volume vésical chez des chats en bonne santé. Cette méthode peut fournir une alternative de transition jusqu'à ce que l'échographie 3D devienne plus facilement accessible.(Traduit par Docteur Sabrina Ayoub).

Fecal shedding of extended-spectrum beta-lactamase-producing Enterobacterales in cats admitted to an animal shelter.

OBJECTIVES: The objective of this study was to evaluate shedding of extended-spectrum beta-lactamase (ESBL)-producing bacteria in cats admitted to an animal shelter. METHODS: Fecal samples were collected from cats admitted to an animal shelter between 12 June and 23 August 2018. Selective enrichment culture for ESBL-producing bacteria was performed and isolates were speciated and tested for selected ESBL genes using PCR. RESULTS: ESBL-producing Enterobacterales were identified in fecal samples from 2/87 (2.3%; 95% confidence interval 0.6-8.0) cats. One isolate was an Escherichia coli that possessed blaCTX-M-1, blaCMY-2 and blaTEM genes. The other was Enterobacter cloacae possessing blaCTX-M-1 and blaCMY-2. CONCLUSIONS AND RELEVANCE: While the study sample size and prevalence rate for ESBL-producing bacteria were low, these data document that cats admitted to similar shelters could harbor these agents. The risk posed by ESBL-producing bacterium shedding in cats, both to cats and other species, is currently unclear. However, these findings support the need for more investigation of interspecies transmission of ESBL-producing bacteria and ESBL genes, as well as the importance of antimicrobial stewardship and routine infection control measures.

Validation of a commercial human ELISA to measure hyaluronic acid concentration in feline plasma.

Our goal was to validate a human hyaluronic acid (HA) ELISA (Hyaluronic acid plus ELISA; TECOmedical Group) for use in feline plasma. Plasma from 5 healthy cats and 5 critically ill cats was used for validation of the assay. Validation methods performed included intra- and inter-assay variability, spike-and-recovery, and dilutional linearity. All measurements were performed in duplicate. The precision study revealed good intra-assay CV of 7.4-8.9%; inter-assay CV was 3.4-4.2%. Extraction efficiency via spiking tests yielded mean recovery of 89.6%. The assay met criteria for acceptable linearity using 3 serial dilutions. Our results demonstrate that this commercial HA ELISA had acceptable analytical performance using feline plasma and could be a useful tool in the veterinary clinical research setting.

Use of serum hyaluronic acid as a biomarker of endothelial glycocalyx degradation in dogs with septic peritonitis.

OBJECTIVE: To describe daily changes in serum concentrations of hyaluronic acid (HA), a biomarker of endothelial glycocalyx degradation, in dogs with septic peritonitis and to determine whether relationships exist among serum concentrations of HA and biomarkers of inflammation and patient fluid status. ANIMALS: 8 client-owned dogs. PROCEDURES: Serum samples that had been collected for a previous study and stored at -80°C were used. Blood samples were collected at admission and daily thereafter during hospitalization and were analyzed for concentrations of HA and interleukins 6, 8, and 10. Patient data including acute patient physiologic and laboratory evaluation score, type and amount of fluids administered daily, and daily CBC and lactate concentration results were recorded. To determine the significant predictors of HA concentration, a general linear mixed model for repeated measures was developed. RESULTS: All dogs survived to discharge. Concentrations of HA ranged from 18 to 1,050 ng/mL (interquartile [25th to 75th percentile] range, 49 to 119 ng/mL) throughout hospitalization. Interleukin-6 concentration was a significant predictor of HA concentration as was total administered daily fluid volume when accounting for interleukin-6 concentration. When fluid volume was analyzed independent of inflammatory status, fluid volume was not a significant predictor. Concentrations of HA did not significantly change over time but tended to increase on day 2 or 3 of hospitalization. CONCLUSIONS AND CLINICAL RELEVANCE: Results supported the theory that inflammation is associated with endothelial glycocalyx degradation. Dogs recovering from septic peritonitis may become more susceptible to further endothelial glycocalyx damage as increasing fluid volumes are administered.

Evaluation of the Distribution and Elimination of Balanced Isotonic Crystalloid, 5% Hypertonic Saline, and 6% Tetrastarch 130/0.4 Using Volume Kinetic Modeling and Analysis in Healthy Conscious Cats.

This prospective, randomized, blinded, interventional cross-over study investigated the distribution, elimination, plasma volume expansion, half-life, comparative potency, and ideal fluid prescription of three commonly prescribed intravenous (IV) fluids in 10 healthy conscious cats using volume kinetic analysis that is novel to veterinary medicine. Each cat received 20 mL/kg of balanced isotonic crystalloid (PLA), 3.3 mL/kg of 5% hypertonic saline (HS), and 5 mL/kg of 6% tetrastarch 130/0.4 (HES) over 15 min on separate occasions. Hemoglobin concentration, red blood cell count, hematocrit, heart rate, and blood pressure were measured at baseline, 5, 10, 15, 20, 30, 40, 50, 60, and every 15 min until 180 min. Urine output was estimated every 30 min using point-of-care bladder ultrasonography. Plasma dilution derived from serial hemoglobin concentration and red blood cell count served as input variables for group and individual fluid volume kinetic analyses using a non-linear mixed effects model. In general, the distribution of all IV fluids was rapid, while elimination was slow. The half-lives of PLA, HS, and HES were 49, 319, and 104 min, respectively. The prescribed fluid doses for PLA, HS, and HES resulted in similar peak plasma volume expansion of 27-30%. The potency of HS was 6 times higher than PLA and 1.7 times greater than HES, while HES was 3.5 times more potent than PLA. Simulation of ideal fluid prescriptions to achieve and maintain 15 or 30% plasma volume expansion revealed the importance of a substantial reduction in infusion rates following initial IV fluid bolus. In conclusion, volume kinetic analysis is a feasible research tool that can provide data on IV fluid kinetics and body water physiology in cats. The rapid distribution but slow elimination of IV fluids in healthy conscious cats is consistent with anecdotal reports of fluid overload susceptibility in cats and warrants further investigation.

Understanding Volume Kinetics: The Role of Pharmacokinetic Modeling and Analysis in Fluid Therapy.

Fluid therapy is a rapidly evolving yet imprecise clinical practice based upon broad assumptions, species-to-species extrapolations, obsolete experimental evidence, and individual preferences. Although widely recognized as a mainstay therapy in human and veterinary medicine, fluid therapy is not always benign and can cause significant harm through fluid overload, which increases patient morbidity and mortality. As with other pharmaceutical substances, fluids exert physiological effects when introduced into the body and therefore should be considered as "drugs." In human medicine, an innovative adaptation of pharmacokinetic analysis for intravenous fluids known as volume kinetics using serial hemoglobin dilution and urine output has been developed, refined, and investigated extensively for over two decades. Intravenous fluids can now be studied like pharmaceutical drugs, leading to improved understanding of their distribution, elimination, volume effect, efficacy, and half-life (duration of effect) under various physiologic conditions, making evidence-based approaches to fluid therapy possible. This review article introduces the basic concepts of volume kinetics, its current use in human and animal research, as well as its potential and limitations as a research tool for fluid therapy research in veterinary medicine. With limited evidence to support our current fluid administration practices in veterinary medicine, a greater understanding of volume kinetics and body water physiology in veterinary species would ideally provide some evidence-based support for safer and more effective intravenous fluid prescriptions in veterinary patients.

High-flow nasal cannula oxygen therapy in acute hypoxemic respiratory failure in 22 dogs requiring oxygen support escalation.

OBJECTIVE: To determine the effect of high-flow nasal cannula (HFNC) oxygen therapy on cardiorespiratory variables and outcome in dogs with acute hypoxemic respiratory failure. DESIGN: Prospective, sequential clinical trial. SETTING: University veterinary teaching hospital. ANIMALS: Twenty-two client-owned dogs that failed to respond to traditional oxygen support. INTERVENTIONS: Initiation of HFNC therapy after traditional oxygen supplementation failed to increase Spo2 > 96% and Pao2 > 75 mm Hg or improve respiratory rate/effort. MEASUREMENTS AND MAIN RESULTS: Physiological variables, blood gas analyses, and dyspnea/sedation/tolerance scores were collected prior to HFNC initiation (on traditional oxygen support [time 0 or T0]), and subsequently during HFNC oxygen administration at time 30 minutes, 60 minutes, and 7 ± 1 hours. Relative to T0, use of HFNC resulted in a decreased respiratory rate at 1 hour (P = 0.022) and 7 hours (P = 0.012), a decrease in dyspnea score at all times (P < 0.01), and an increase in Spo2 at all times (P < 0.01). There was no difference in arterial/venous Pco2 relative to T0, although Paco2 was correlated with flow rate. Based on respiratory assessment, 60% of dogs responded to HFNC use by 30 minutes, and 45% ultimately responded to HFNC use and survived. No clinical air-leak syndromes were observed. CONCLUSIONS: HFNC use improved oxygenation and work of breathing relative to traditional oxygen therapies, without impairing ventilation. HFNC use appears to be a beneficial oxygen support modality to bridge the gap between standard oxygen supplementation and mechanical ventilation.

Preliminary evaluation of the use of high-flow nasal cannula oxygen therapy during recovery from general anesthesia in dogs with obstructive upper airway breathing.

BACKGROUND: Brachycephalic airway syndrome can pose a risk of complicated recovery from anesthesia as a result of irritation to the excess pharyngeal andlaryngeal tissue present in affected dogs. High-flow nasal cannula (HFNC) oxygen therapy is a respiratory support modality that offers provision of continuous positive airway pressure via high gas flow rates. The HFNC system actively warms and humidifies inspired gases, which improves comfort and facilitates tolerance of the high flow rates in people and dogs. HFNC oxygen therapy was applied to brachycephalic dogs that developed increased work of breathing or hypoxemia in the recovery phase of anesthesia to determine if this device would be tolerable and effective for relief of upper respiratory difficulty. KEY FINDINGS: The HFNC nasal prong interface is well suited to the brachycephalic facial structure. The application of HFNC was found to reduce dyspnea scores in patients with signs of upper airway obstruction after general anesthesia. Aerophagia and changes in PCO2 were noted. SIGNIFICANCE: Application of HFNC in the recovery period may result in improved airflow during times of somnolent obstructive breathing, not unlike the use of continuous positive airway pressure therapy in sleep-disordered breathing in people.

Dose and cardiopulmonary effects of propofol alone or with midazolam for induction of anesthesia in critically ill dogs.

OBJECTIVE: To determine the dose and cardiopulmonary effects of propofol alone or with midazolam for induction of anesthesia in American Society of Anesthesiologists status ≥III dogs requiring emergency abdominal surgery. STUDY DESIGN: Prospective, randomized, blinded, clinical trial. ANIMALS: A total of 19 client-owned dogs. METHODS: Dogs were sedated with fentanyl (2 µg kg-1) intravenously (IV) for instrumentation for measurement of heart rate, arterial blood pressure, cardiac index, systemic vascular resistance index, arterial blood gases, respiratory rate and rectal temperature. After additional IV fentanyl (3 µg kg-1), the quality of sedation was scored and cardiopulmonary variables recorded. Induction of anesthesia was with IV propofol (1 mg kg-1) and saline (0.06 mL kg-1; group PS; nine dogs) or midazolam (0.3 mg kg-1; group PM; 10 dogs), with additional propofol (0.25 mg kg-1) IV every 6 seconds until endotracheal intubation. Induction/intubation quality was scored, and anesthesia was maintained with isoflurane. Variables were recorded for 5 minutes with the dog in lateral recumbency, breathing spontaneously, and then in dorsal recumbency with mechanical ventilation for the next 15 minutes. A general linear mixed model was used with post hoc analysis for multiple comparisons between groups (p < 0.05). RESULTS: There were no differences in group demographics, temperature and cardiopulmonary variables between groups or within groups before or after induction. The propofol doses for induction of anesthesia were significantly different between groups, 1.9 ± 0.5 and 1.1 ± 0.5 mg kg-1 for groups PS and PM, respectively, and the induction/intubation score was significantly better for group PM. CONCLUSIONS AND CLINICAL RELEVANCE: Midazolam co-induction reduced the propofol induction dose and improved the quality of induction in critically ill dogs without an improvement in cardiopulmonary variables, when compared with a higher dose of propofol alone.

Prescribing patterns and comparison of culture versus empiric-based selection of meropenem in cats and dogs in a veterinary teaching hospital (2011-2018).

The utilization of meropenem in a small animal veterinary teaching hospital over a 7-year period was retrospectively analyzed, and culture (CBD) versus empiric-based decisions (EBD) were compared. Meropenem was infrequently prescribed at a rate of 0.50 prescriptions/1000 admissions in cats and 0.58/1000 in dogs. The most common condition for meropenem prescription in both cats and dogs was septic peritonitis (15/52, 28.8%). Overall 65.4% of meropenem prescriptions were initiated without, or prior to, culture results indicating a need for the drug. Based on retrospective analysis of culture and susceptibility results, only 2.9% of empirical meropenem selections were indicated, while the majority were not indicated (52.9%), or of questionable indication (44.2%).

Patrons d'ordonnance et comparaison de la culture versus le choix empirique de méropénème chez les chats et chiens dans un hôpital d'enseignement vétérinaire (2011­2018). L'utilisation de méropénème dans un hôpital d'enseignement vétérinaire pour animaux de compagnie durant une période de 7 ans fut analysée rétrospectivement, et la culture (CBD) versus la décision empirique (EBD) furent comparées. Le méropénème était prescrit peu fréquemment à une fréquence de 0,50 ordonnances/1000 admissions chez les chats et 0,58/1000 chez les chiens. La condition la plus fréquente pour la prescription de méropénème était la péritonite septique (15/52, 28,8 %). Globalement, 65,4 % des ordonnances de méropénème étaient initiés sans, ou précédent, les résultats de culture indiquant un besoin pour ce médicament. Basé sur l'analyse rétrospective des résultats de culture et de sensibilité, dans seulement 2,9 % des cas le choix empirique de méropénème état indiqué alors que dans la majorité des cas (52,9 %), ce n'était pas indiqué ou c'était une indication discutable.(Traduit par Dr Serge Messier).

Feasibility of a novel 3-dimensional mathematical algorithmic computation of feline bladder volumes using point-of-care longitudinal and transverse cysto-colic ultrasonographic images.

Conventional geometric formulas for estimating bladder volume assume that bladders have a perfectly uniform spheroid geometry. Bladders are often irregularly shaped, however, especially when under-filled or distorted by a full colon, which results in inaccurate ultrasonographic linear measurements and volume estimation. This pilot study investigates the feasibility, inter-observer reliability (reproducibility), robustness, and agreement of a novel 3-dimensional bladder volume computation method using bladder circumference tracing compared to a published feline linear bladder dimension formula. Paired sets of longitudinal and transverse B-mode bladder ultrasound images (n = 228) were acquired by 2 observers with different point-of-care ultrasonography skills using 10 healthy purpose-bred cats positioned in dorsal recumbency at various time points. Using strict criteria for Lin's concordance correlation coefficient, inter-observer agreements (n = 223) were found to be substantial (0.95 to 0.99) with statistically significant but clinically non-significant median differences (biases) of 0.96 mL [interquartile range (IQR): 0.16 to 2.46, P < 0.001] and 0.23 mL (IQR: 0.88 to 1.97, P = 0.006) when bladder circumference tracings were made on similar sets of ultrasound images respectively. Inter-observer agreements improved from substantial (0.95 to 0.99) to almost perfect (> 0.99) strength-of-agreement as the quality of ultrasound images improved. The bladder circumference tracing method showed moderate (0.90 to 0.95) strength-of-agreement with the recently published feline linear bladder dimension formula, with significant additive median differences (biases) of -6.76 mL (IQR: -9.06 to -3.88, P < 0.001) and -6.44 mL (IQR: -11.41 to -3.81, P < 0.001) recorded by each observer (n = 111, n = 83), respectively. Data obtained from orthogonal ultrasonographic bladder circumference tracings justify further investigation into use of this method for estimating bladder volume in cats.

Les formules géométriques conventionnelles pour estimer le volume de la vessie présument que les vessies ont une géométrie sphéroïde uniforme. Les vessies sont souvent de forme irrégulière, toutefois, spécialement lorsqu'elles ne sont pas remplies complètement ou sont déformées par un côlon rempli, ce qui résulte en des mesures linéaires imprécises par échographie et des estimations erronées de volume. La présente étude pilote a examiné la faisabilité, la fiabilité inter-observateur (reproductibilité), robustesse, et accord d'une nouvelle méthode de computation en 3-D du volume de la vessie en utilisant un traçage de la circonférence de la vessie comparée à une formule publiée utilisant la dimension linéaire de la vessie féline. Des images échographiques en mode B pairées longitudinale et transverse de la vessie (n = 228) furent obtenues par deux observateurs avec des compétences différentes en échographie au point de service en utilisant 10 chats en santé positionnés en décubitus dorsal à différents moments. En utilisant des critères stricts pour le coefficient de corrélation de concordance de Lin, les accords inter-observateurs (n = 223) ont été notés comme substantiels (0,95 à 0,99) avec une différence médiane (biais) statistiquement significative mais cliniquement non-significative de 0,96 mL [écart interquartile (IQR) : 0,16 à 2,46, P < 0,001] et 0,23 mL (IQR : 0,88 à 1,97, P = 0,006) lorsque les traçages de la circonférence de la vessie étaient effectués sur des groupes similaires d'images échographiques respectivement. La force des accords inter-observateurs se sont améliorés de substantiels (0,95 à 0,99) jusqu'à presque parfaits (> 0,99) à mesure que la qualité des images échographiques s'améliorait. La méthode de traçage de la circonférence de la vessie a montré une force d'accord modérée (0,90 à 0,95) avec la formule récemment publiée des dimensions linéaires de la vessie, avec une différence médiane (biais) additive significative de −6,76 mL (IQR : −9,06 à −3,88, P < 0,001) et −6,44 mL (IQR : −11,41 à −3,81, P < 0,001) notée par chaque observateur (n = 111, n = 83), respectivement. Les données obtenues par traçage orthogonal de la circonférence de la vessie justifient des études supplémentaires sur l'utilisation de cette méthode pour estimer le volume de la vessie chez les chats.(Traduit par Docteur Serge Messier).

A pilot study evaluating the effects of prestorage leukoreduction on markers of inflammation in critically ill dogs receiving a blood transfusion.

OBJECTIVES: To compare markers of inflammation after transfusion of leukoreduced (LR) packed RBCs (pRBCs) versus non-LR pRBCs in dogs with critical illness requiring blood transfusion, and to report survival to discharge and rates of transfusion reactions in these dogs. DESIGN: Prospective randomized blinded clinical study June 2014-September 2015. SETTING: University veterinary teaching hospital. ANIMALS: Twenty-three client-owned critically ill dogs, consecutively enrolled. INTERVENTIONS: Dogs requiring a single pRBC transfusion were randomized into the LR or non-LR pRBC group. Exclusion criteria included: requirement for multiple blood products, history of previous blood transfusion, and administration of anti-inflammatory or immunosuppressive medication prior to enrollment. MEASUREMENTS: Blood samples were obtained immediately prior to transfusion, then 2 and 24 hours following transfusion. Parameters measured at each time point included: PCV, WBC count, segmented and band neutrophil counts, fibrinogen, and plasma lactate and C-reactive protein concentrations. Acute patient physiologic and laboratory evaluation fast score was calculated on admission. RESULTS: Eleven dogs were included in the LR group and 12 in the non-LR group; scores of illness severity were not significantly different between groups. Total WBC count was significantly higher in the non-LR versus LR group 24 hours following pRBC transfusion, but this difference was not evident 2 hours following transfusion. No other inflammatory parameters at any time point were significantly different between LR versus non-LR pRBC transfused dogs. Survival rates to discharge for LR and non-LR groups were 8/11 and 9/12, respectively. Acute transfusion reactions were identified in 1/11 and 2/12 dogs in the LR and non-LR group, respectively. All transfused blood was stored ≤12 days. CONCLUSIONS: Most markers of inflammation did not significantly increase following transfusion of LR versus non-LR pRBCs stored ≤12 days in ill dogs. Further prospective, randomized trials are needed in clinically ill dogs to determine the benefit of prestorage leukoreduction.

Comparison of high flow nasal cannula oxygen administration to traditional nasal cannula oxygen therapy in healthy dogs.

OBJECTIVE: To determine the feasibility, degree of respiratory support, and safety of high flow nasal cannula (HFNC) oxygen therapy in sedated and awake healthy dogs, when compared to traditional nasal cannula (TNC) oxygen administration. DESIGN: Randomized experimental crossover study. SETTING: University research facility. ANIMALS: Eight healthy dogs. INTERVENTIONS: Variable flow rates (L/kg/min) were assessed, TNC: 0.1, 0.2, and 0.4 and HFNC: 0.4, 1.0, 2.0, and 2.5. HFNC was assessed in sedated and awake dogs. MEASUREMENTS: Variables measured included: inspiratory/expiratory airway pressures, fraction of inspired oxygen (FiO2 ), end-tidal oxygen (ETO2 ), end-tidal carbon dioxide (ETCO2 ), partial pressure of oxygen (PaO2 ), partial pressure of carbon dioxide (PaCO2 ), temperature, heart/respiratory rate, arterial blood pressure, and pulse oximetry. Sedation status, complications, and predefined tolerance and respiratory scores were recorded. MAIN RESULTS: Using HFNC, continuous positive airway pressure (CPAP) was achieved at 1 and 2 L/kg/min. CPAP was not higher at 2.5 than 2 L/kg/min, with worse tolerance scores. Expiratory airway pressures were increased when sedated (P = 0.006). FiO2 at 0.4 L/kg/min for both methods was 72%. FiO2 with TNC 0.1 L/kg/min was 27% and not different from room air. The FiO2 at all HFNC flow rates ≥1 L/kg/min was 95%. PaO2 for HFNC 0.4 L/kg/min was lower than at other flow rates (P = 0.005). The only noted complication was aerophagia. PaCO2 was increased with sedation and use of HFNC when compared to baseline (P = 0.006; P < 0.01). CONCLUSIONS: Use of HFNC in dogs is feasible and safe, provides predictable oxygen support and provides CPAP, but may cause a mild increase in PaCO2 . Flow rates of 1-2 L/kg/min are recommended. If using TNC, flow rates above 0.1 L/kg/min may attain higher FiO2 .