Reversal of arterial oxygen desaturation with the use of an oxygen concentrator during injectable anaesthesia in feral cats positioned in the Trendelenburg, dorsal or lateral surgical position.

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

INTRODUCTION: Cette étude a observé les effets d'une supplémentation en oxygène, via un concentrateur d'oxygène, sur l'oxygénation du sang artériel périphérique (SpO2) mesurée par oxymétrie de pouls chez des chats anesthésiés subissant une stérilisation dans trois positions chirurgicales différentes. Au total, 192 chats sauvages femelles ont été examinés dans le cadre d'un programme de piégeage, de stérilisation et de remise en liberté à grande échelle. Les chats ont été anesthésiés avec une combinaison de butorphanol (0,4 mg / kg), de kétamine (7­10 mg / kg) et de médétomidine (0,03­0,05 mg / kg) appliquée par voie intramusculaire. Les chats ont été répartis au hasard pour subir une stérilisation en position de Trendelenburg (TR) (inclinaison de la tête de 70° vers le bas), en décubitus latéral (LR) ou en décubitus dorsal (DR). Les chats respiraient spontanément soit de l'air ambiant, soit de l'oxygène à raison de 2 L/minute par l'intermédiaire d'un masque facial bien ajusté. Le pouls (en battements par minute), la fréquence respiratoire (en respirations par minute) et la SpO2 (en pourcentage) ont été mesurés au départ en décubitus latéral gauche, puis en continu après avoir été placés dans la position chirurgicale attribuée. À la fin de l'opération, les chats ont été replacés en décubitus latéral gauche et tous les paramètres ont été réévalués au bout de cinq minutes. Dans l'ensemble, 33 % des chats présentaient une désaturation sévère en oxygène artériel (SpO2 < 90 %) au départ lorsqu'ils respiraient de l'air ambiant. Lorsque de l'oxygène a été ajouté pendant la procédure, la désaturation en oxygène artériel s'est résorbée chez tous les chats. À la fin de l'intervention, 29 % des chats étaient hypoxémiques lorsque l'oxygène n'était pas administré, avec un pourcentage global plus élevé de chats hypoxémiques en décubitus dorsal qu'en décubitus latéral. Tous les chats se sont bien remis de l'opération et ont été libérés dans les 24 heures suivant l'anesthésie. La désaturation en oxygène artériel est fréquente chez les chats anesthésiés par injection pour la stérilisation dans des conditions de terrain. La supplémentation en oxygène administrée via un masque étanche a résolu la désaturation en oxygène artériel dans cette population de chats sauvages, quelle que soit la position chirurgicale et la supplémentation en oxygène est donc recommandée dans tous les cas.

Effects of brotizolam as a co-agent with ketamine for induction of anaesthesia in calves.

Anaesthesia in food producing animals in the EU and UK is legally limited to a narrow choice of drugs; the only licensed benzodiazepine being brotizolam. The aim of this study was to investigate the effects of brotizolam as a co-agent with ketamine on the quality of induction, intubation, muscle relaxation and recovery from isoflurane anaesthesia. Seventeen calves were enrolled in this prospective, blinded, randomized experimental study. Calves were sedated with 0.05 mg/kg xylazine and 0.1 mg/kg butorphanol IV. After assessing the quality of sedation, anaesthesia was induced with 2 mg/kg ketamine (group KETA) or 2 mg/kg ketamine with 2 µg/kg brotizolam IV (group BROTI). An additional 1 mg/kg ketamine was administered IV every 2 min until intubation was possible. Anaesthesia was maintained with isoflurane in a mixture of oxygen and air. The amount of ketamine required, quality of induction, intubation, muscle relaxation, and recovery were scored and compared between groups using ordinal regression models (P < 0.05 was considered statistically significant). Sedation scores did not differ significantly between groups but were positively associated with the quality of recovery (P = 0.0098). Group BROTI was associated with a lower quality of induction (P < 0.0001), intubation (P = 0.0203) and muscle relaxation (P = 0.0043). The sedation score and treatment had no effect on the number of attempts of intubation, additional ketamine doses, time to extubation and recovery time. Brotizolam had a negative effect on the quality of induction, intubation, and muscle relaxation compared to ketamine alone. We do not recommend using brotizolam under these circumstances.

How painful are cats after neutering - a field study using multimodal analgesia with intraperitoneal ropivacaine in a -neuter-return program in feral cats.

INTRODUCTION: For a large-scale trap-neuter-return program 119 cats were anaesthetised with an intramuscular combination of 0,03-0,05 mg/kg medetomidine, 7-10 mg/kg ketamine and 0,4 mg/kg butorphanol. Cats received intraoperative 4 mg/kg tolfenamic acid subcutaneously and before closure of abdominal wall either 2 mg/kg ropivacaine (ROPI) intraperitoneal or saline (NaCl) in equal volumes. Pain was scored one, six and 20 hours postoperative with the modified Glasgow Composite Pain Scale (mGCPS) and the modified Colorado State University Scale (mCSU). There was no significant difference in the pain scores between the two groups, but the pain scores with both pain scales were significant higher (p < 0,001 for both) six hours compared to one and 20 hours postoperative. Cut-off value on the pain scales (necessitating rescue analgesia) was exceeded in 34,5 % for mGCPS and in 39,5 % for mCSU. Cats with a higher pain score showed a lower food intake (p .

INTRODUCTION: L'objectif de cette étude clinique prospective, randomisée, en aveugle et d'observation était d'étudier les effets de la ropivacaïne administrée par voie intrapéritonéale pour l'analgésie postopératoire chez des chats harets femelles subissant une ovariectomie. Dans le cadre d'un programme de piégeage, de stérilisation et de remise en liberté à grande échelle, 119 chattes ont été anesthésiées par une combinaison intramusculaire de 0,03 à 0,05 mg/kg de médétomidine, 7 à 10 mg/kg de kétamine et 0,4 mg/kg de butorphanol. Les chats ont reçu en peropératoire 4 mg/kg d'acide tolfénamique par voie sous-cutanée et, avant la fermeture de la paroi abdominale, 2 mg/kg de ropivacaïne (ROPI) par voie intrapéritonéale ou du sérum physiologique (NaCl) en volumes égaux. La douleur a été évaluée une, six et 20 heures après l'opération à l'aide de l'échelle de Glasgow de la douleur composite modifiée (mGCPS) et de l'échelle modifiée de l'Université d'État du Colorado (mCSU). Il n'y avait pas de différence significative dans les scores de douleur entre les deux groupes, mais les scores de douleur avec les deux échelles de douleur étaient significativement plus élevés (p < 0,001 pour les deux) six heures par rapport à une et 20 heures postopératoires. La valeur seuil des échelles de douleur (nécessitant une analgésie de secours) a été dépassée dans 34,5 % des cas pour le mGCPS et dans 39,5 % des cas pour le mCSU. Les chats ayant un score de douleur plus élevé ont présenté une prise alimentaire plus faible (p < 0,001). L'administration intrapéritonéale de ropivacaïne n'a pas amélioré significativement l'analgésie par rapport à une solution saline intrapéritonéale. La combinaison anesthésique couramment utilisée en pratique pour la stérilisation (médétomidine, kétamine, butorphanol), complétée par des médicaments analgésiques non stéroïdiens supplémentaires, a entraîné une analgésie postopératoire insuffisante 6 heures après la chirurgie chez plus d'un tiers des chats étudiés.

[Evaluation of isoflurane inhalation -anesthesia machines available in Switzerland for on farm piglet -castrations]. / Kritische Evaluation der in der Schweiz zur Verfügung stehenden Inhalations­anästhesiegeräte zur Ferkelkastration ­unter Isoflurananästhesie im Stall.

INTRODUCTION: The present study analyzed piglet castration under isoflurane anesthesia in ten farms. The data of 202 male piglets in the age between three to eleven days and with a body weight of 1 - 4,7 kg were collected. The aim of this study was to compare the PorcAnest®, Pignap® and Pigsleeper® anesthesia machines used in Switzerland. Isoflurane, carbon dioxide (CO2) and oxygen (O2) values were measured in relation to their significance for anesthesia quality. Therefore, preoperative stress level and movements were assessed during skin incision and the dissection of the spermatic cords. Isoflurane, CO2 and O2 values were recorded in the inhaled and exhaled gases next to the nostrils at 30, 60, 75 and 90 seconds after the start of anesthesia. Movements to the skin incisions and dissection of the spermatic cord were observed in 32 % and 37 % respectively. Movements increased with the decrease of measured inspiratory and expiratory isoflurane values (FIIso and ETIso). Significantly lower inspiratory O2 values (FIO2: 12 - 21 volume % vs 21 - 95 volume %) and stronger movements were measured in anesthesia machines using room air compared to machines operated with medical oxygen. Results indicate a potential for improvement in anesthesia deph piglet castration under isoflurane inhalaton anesthesia and THE measured isoflurane, CO2 and O2 values differ significantly between PorcAnest®, Pignap® and Pigsleeper® anesthesia machines. These fluctuations could be recognized and reduced by annual professional maintenance and / or the addition of an anesthetic gas analyzer. In addition, a change to medical oxygen is indicated for all anesthetic machines. Anesthesia machines have to be optimized in consultation with the manufacturers as soon as possible and the farmers have to be trained and sensitized to ensure pain-free castration.

INTRODUCTION: La présente étude a analysé la castration de porcelets sous anesthésie à l'isoflurane dans dix exploitations. Les données de 202 porcelets mâles âgés de trois à onze jours et pesant entre 1 et 4,7 kg ont été recueillies. Le but de cette étude était de comparer les appareils d'anesthésie PorcAnest®, Pignap® et Pigsleeper® utilisés en Suisse. Les valeurs d>isoflurane, de dioxyde de carbone (CO2) et d>oxygène (O2) ont été mesurées en fonction de leur importance pour la qualité de l>anesthésie. Pour cela, le niveau de stress préopératoire et les mouvements ont été évalués lors de l'incision cutanée et la dissection des cordons spermatiques. Les valeurs d'isoflurane, de CO2 et d'O2 ont été enregistrées dans les gaz inhalés et expirés à côté des narines à 30, 60, 75 et 90 secondes après le début de l'anesthésie. Des mouvements lors des incisions cutanées et de la dissection du cordon spermatique ont été observés respectivement dans 32 % et 37 % des cas. Les mouvements ont augmenté avec la diminution des valeurs d'isoflurane inspiratoires et expiratoires mesurées (FIIso et ETIso). Des valeurs d'O2 inspiratoire significativement plus faibles (FIO2 : 12 - 21 % du volume contre 21 - 95 % du volume) et des mouvements plus importants ont été constatés avec les appareils d'anesthésie utilisant l'air ambiant par rapport à ceux fonctionnant avec de l'oxygène médical. Les résultats indiquent qu'il existe un potentiel d'amélioration de la profondeur d'anesthésie dans la castration des porcelets sous anesthésie par inhalation d'isoflurane et que les valeurs mesurées d'isoflurane, de CO2 et d'O2 diffèrent significativement entre les appareils d'anesthésie PorcAnest®, Pignap® et Pigsleeper®. Ces fluctuations pourraient être identifiées et réduites par un entretien professionnel annuel et/ou par l'ajout d'un analyseur de gaz anesthésique. De plus, un passage à l'oxygène médical est indiqué pour tous les appareils d'anesthésie. Les appareils d'anesthésie doivent être optimisés en concertation avec les fabricants dans les plus brefs délais et les éleveurs doivent être formés et sensibilisés pour assurer une castration sans douleur.

Butorphanol induces anxiety-like -behaviour and distress in piglets.

INTRODUCTION: In a previous study that used butorphanol in pigs before castration performed under isoflurane anaesthesia, severe adverse effects were recorded. As in pigs, this has not been reported before, we aimed to investigate the effects of butorphanol in piglets. In this study ten 27 days old piglets were randomly allocated to receive either 0,2 mg/kg butorphanol (group B) or saline 0,9% (control group C) intramuscularly. Their behaviour was assessed for 60 minutes by two independent observers from videotapes. Two to 15 minutes after application, piglets in group B showed restlessness, distress and excessive vocalisation. Locomotor activity was increased, the piglets laid down considerably less frequently (p = 0,034) and for shorter time periods (p = 0,0014) during the first 40 minutes compared to group C. Group C animals slept most time of the experiment (45,1 ± 2,9 minutes in group C vs 12,7 ± 2,9 minutes in group B, p .

INTRODUCTION: Le butorphanol induit des comportements anxieux et de la détresse chez les porcelets Dans une précédente étude utilisant le butorphanol chez les porcs avant la castration réalisée sous anesthésie à l'isoflurane, des effets indésirables sévères ont été rapportés. Cela n'étant pas décrit auparavant chez les porcs, nous avons cherché à étudier les effets du butorphanol chez les porcelets. Dix porcelets âgés de 27 jours ont été répartis aléatoirement (en double aveugle) pour recevoir 0,2 mg/kg de butorphanol (groupe B) ou du sérum physiologique à 0,9% (groupe de contrôle C) par voie intramusculaire. Leur comportement a été évalué pendant 60 minutes par deux observateurs indépendants à partir d'enregistrements vidéo. Deux à 15 minutes après l'injection, les porcelets du groupe B ont présenté de l'agitation, de la détresse et des vocalisations excessives. L'activité locomotrice a augmenté : lors des 40 premières minutes, les porcelets se sont couchés significativement moins fréquemment (p = 0,034) et pour des périodes plus courtes (p = 0,0014) par rapport au groupe C. Les animaux du groupe C ont dormi la majorité du temps de l'expérience (45,1 ± 2,9 minutes dans le groupe C vs 12,7 ± 2,9 minutes dans le groupe B, p .

Cats undergoing spay with medetomidine, ketamine and butorphanol develop arterial oxygen desaturation independent of surgical positioning and increased intraocular pressure in Trendelenburg position.

INTRODUCTION: This study observed the effects of three different surgical positions on arterial blood oxygenation measured noninvasively by pulse oximetry (SpO2) and on intraocular pressure (IOP) in anaesthetised cats undergoing spay. A total of 222 female feral cats were anaesthetised for a large-scale trap-neuter-return program with an intramuscular combination of medetomidine (0.03 - 0.05 mg/kg), ketamine (7 - 10 mg/kg) and butorphanol (0.4 mg/kg). Cats were randomly allocated to undergo spay in either Trendelenburg (70° downward head tilt), lateral or dorsal recumbency. SpO2 and pulse rate were measured at baseline, prior to surgical positioning, after one minute in surgical position and in one-minute intervals after surgical incision. Intraocular pressure was measured before positioning and at the end of surgery. At the end of surgery, all cats were placed into left lateral recumbency and all parameters were revaluated after five minutes. No significant differences between the three positions were found regarding SpO2, but an increase over time was observed. In total, 52 ± 10% (mean ± SD) of cats were hypoxaemic (SpO2 < 90%) at baseline. SpO2 improved over time, but 27 ± 3% (mean ± SD) of the cats remained hypoxaemic at the end of surgery. Trendelenburg position increased IOP during surgery (mean 31 ± 6 mmHg, individual max. 48 mmHg, versus 17 ± 4 mmHg in dorsal/lateral recumbency) but normalised after 5 mins in lateral recumbence. All cats recovered well from surgery and were released within 24 hours post-anaesthesia. Surgical position was shown to have no notable influence on SpO2 during anaesthesia in cats not receiving oxygen supplementation, whereas Trendelenburg position led to increased IOP. Oxygen supplementation is recommended with this anaesthetic protocol, as hypoxaemia is frequently observed.

INTRODUCTION: Dans cette étude, on a observé les effets de trois positions chirurgicales différentes sur l'oxygénation du sang artériel mesurée de manière non invasive par oxymétrie de pouls (SpO2) et sur la pression intraoculaire (PIO) chez des chattes anesthésiées subissant une stérilisation. Un total de 222 chattes sauvages ont été, dans le cadre d'un large programme de piégeage-castration-libération, anesthésiées avec une combinaison de médétomidine (0,03 à 0,05 mg/kg), de kétamine (7 à 10 mg/kg) et de butorphanol (0,4 mg/kg) par voie intramusculaire. Les chattes ont été réparties au hasard pour subir une stérilisation en Trendelenburg (inclinaison de la tête à 70 ° vers le bas), en décubitus latéral ou dorsal. La SpO2 et la fréquence du pouls ont été mesurées au départ, avant le positionnement chirurgical, après une minute en position chirurgicale et à des intervalles d'une minute après l'incision chirurgicale. La pression intraoculaire a été mesurée avant le positionnement et à la fin de la chirurgie. À la fin de la chirurgie, toutes les chattes ont été placées en décubitus latéral gauche et tous les paramètres ont été réévalués après cinq minutes. Aucune différence significative entre les trois positions n'a été constatée concernant la SpO2, mais une augmentation au fil du temps a été observée. Au total, 52 ± 10% (moyenne ± SD) des chattes étaient hypoxémiques (SpO2.

Effect of 50 mg/kg intravenous tranexamic acid on coagulation assessed by rotational thromboelastometry (ROTEM) in healthy Beagle dogs.

INTRODUCTION: In people, the antifibrinolytic drug tranexamic acid reduces bleeding and the need for blood products with both normal and exaggerated fibrinolysis without increasing the number of thromboembolic events. In dogs, in addition to prevention and treatment of bleeding, higher doses of tranexamic acid can be used to induce vomiting. The objective of this study was to evaluate the effect of a high dose of tranexamic acid on the coagulation of healthy Beagle dogs. A prospective trial was conducted in eight healthy Beagles receiving tranexamic acid for a concurrent trial evaluating different antiemetics. Rotational thromboelastometry (ROTEM) analysis (EXTEM, APTEM, FIBTEM, INTEM) was performed before and 30 minutes after intravenous administration of 50 mg/kg tranexamic acid. ROTEM parameters before and after tranexamic acid administration and between EXTEM and APTEM were compared with Wilcoxon matched-pairs signed rank test and data is presented as median (range). After tranexamic acid administration, FIBTEM clotting time became significantly shorter (p=0.03) from 37 s (28-124 s) to 33 s (27-40 s) and INTEM clot formation time significantly decreased (p=0.02) from 82 s (47-132 s) to 60 s (43-107 s). After tranexamic acid APTEM MCF was significantly weaker (p=0.01) with 45 mm (30-63 mm) than EXTEM MCF with 55 mm (43-69 mm) and than APTEM MCF before tranexamic acid with 55 mm (43-69 mm) (p=0.02). All other analysed parameters including maximum lysis did not change after administration of tranexamic acid. The administration of 50 mg/kg intravenous tranexamic acid resulted in small changes in ROTEM profiles without inducing a hypercoagulable clot. In conclusion, tranexamic acid can safely be administered to healthy dogs with normal coagulation profiles. As an additional finding, APTEM parameters measured in the current study do not support the use of this test in dogs.

INTRODUCTION: Chez l'homme présentant une fibrinolyse normale et exagérée, l'acide tranexamique, un agent antifibrinolytique, réduit les saignements et le besoin de produits sanguins sans augmenter le nombre d'événements thromboemboliques. Chez les chiens, en plus de la prévention et du traitement des saignements, des doses plus élevées d'acide tranexamique peuvent être utilisées pour provoquer des vomissements. L'objectif de cette étude était d'évaluer l'effet d'une dose élevée d'acide tranexamique sur la coagulation de chiens Beagle en bonne santé. Un essai prospectif a été mené chez huit Beagles en bonne santé recevant de l'acide tranexamique dans le cadre d'un essai simultané évaluant différents antiémétiques. Une analyse de la thromboélastométrie rotationnelle (ROTEM) (EXTEM, APTEM, FIBTEM, INTEM) a été réalisée avant et 30 minutes après l'administration intraveineuse de 50 mg/kg d'acide tranexamique. Les paramètres ROTEM avant et après l'administration d'acide tranexamique et entre EXTEM et APTEM ont été comparés au test de rang de Wilcoxon à paires appariées et les données sont présentées sous forme de médiane. Après administration de l'acide tranexamique, le temps de coagulation de FIBTEM est devenu significativement plus court (p = 0,03) de 37 s (28-124 s) à 33 s (27-40 s) et le temps de formation du caillot INTEM a été significativement réduit (p = 0,02) de 82 s (47-132 s) à 60 s (43-107 s). Après l'acide tranexamique, APTEM MCF était significativement plus faible (p = 0,01) avec 45 mm (30-63 mm) que EXTEM MCF avec 55 mm (43-69 mm) et qu'APTEM MCF avant l'acide tranexamique avec 55 mm (43-69 mm) (p = 0,02). Tous les autres paramètres analysés, y compris la lyse maximale, n'ont pas changé après l'administration d'acide tranexamique. L'administration de 50 mg/kg d'acide tranexamique par voie intraveineuse a entraîné de légers changements dans les profils ROTEM sans induire de caillot hypercoagulable. En conclusion, l'acide tranexamique peut être administré en toute sécurité à des chiens en bonne santé présentant des profils de coagulation normaux. Autre constatation supplémentaire, les paramètres APTEM mesurés dans la présente étude n'appuient pas l'utilisation de ce test chez le chien.

Optimization of analgesia for piglet castration under isoflurane anaesthesia with parenteral butorphanol, meloxicam or intratesticular lidocaine.

INTRODUCTION: This blinded prospective study investigated analgesic effects of intramuscular (IM) butorphanol, meloxicam or intratesticular (IT) lidocaine for castration of 7-14 days old piglets under isoflurane anaesthesia. 66 piglets were randomly injected with: meloxicam IM (0.4 mg/kg; group M), butorphanol IM (0.2 mg/kg; group B), or both (group BM) 20 minutes prior to castration, or lidocaine IT (4 mg/kg (group ML4) or 8 mg/kg (group ML8)) together with meloxicam IM (0.4 mg/kg) under anaesthesia with 1.8% end-tidal isoflurane. Heart rate, respiratory rate, mean arterial blood pressure and end-tidal carbon dioxide were recorded. Anaesthesia quality was scored and postoperative behaviour assessed. As butorphanol caused unacceptable side effects, its use was stopped. Group M showed worse anaesthesia quality than ML4 and ML8 (higher incidence of movements: 11/17, 3/18 and 4/17, respectively). There were no significant differences between groups regarding parameters measured during castration. Postoperative behaviour did not differ between groups. For castration of 7-14 days old piglets under isoflurane anaesthesia, IT lidocaine provides an additional side effect free analgesia.

INTRODUCTION: Cette étude prospective en aveugle étudie l'effet analgésique de l'injection intramusculaire (IM) de butorphanol et de méloxicam ou de l'injection intra-testiculaire (IT) de lidocaïne pour la castration, sous anesthésie à l'isoflurane, de porcelets âgés de 7 à 14 jours. Soixante-six porcelets ont reçu de manière aléatoire soit du méloxicam IM (0.4 mg/kg; groupe M), soit du butorphanol IM (0.2 mg/kg; groupe B), soit les deux substances (groupe MB) 20 minutes avant la castration, soit de la lidocaïne IT (4 mg/kg (groupe ML4) ou 8 mg/kg (groupe ML8)) ainsi que du méloxicam IM (0.4 mg/kg), avec une anesthésie à l'isoflurane à 1.8% en fin d'expiration. Les fréquences cardiaques et respiratoires, la pression artérielle moyenne et le CO2 en fin d'expiration ont été documentés. La qualité de l'anesthésie a été estimée et le comportement post-opératoire observé. Le butorphanol a causé des effets secondaires inacceptables et son usage a été stoppé. Le groupe M montrait une plus mauvaise qualité d'anesthésie que les groupes ML4 et ML8 (plus grande incidence de mouvements : 11/17, 3/18 et 4/17). Les autres paramètres intra opératoires ne présentaient pas de différences significatives et on a pas constaté de différences entre les groupes dans la phase postopératoire. Pour la castrations de porcelets âgés de 7 à 14 jours sous anesthésie à l'isoflurane, l'utilisation intra testiculaire de lidocaïne représente une analgésie supplémentaire dépourvue d'effets secondaires.

[Evaluation of a field-suitable injection anesthesia protocol for the castration of 8 to 14 days old piglets]. / Ermittlung eines feldtauglichen Injektionsanästhesieprotokolls zur Kastration von 8 bis 14-tägigen Ferkeln.

INTRODUCTION: The aim of this study was to find an intramuscularly (IM) injectable anaesthetic combination for 8 to 14-days old piglets, that guarantees a calm induction and sufficient quality of anaesthesia without excitations with a maximum of two hours long lasting recovery. In preliminary dose finding trials, different combinations of -ketamine, azaperone and romifidine were compared. A constant dose of 0.2 mg/kg of butorphanol was added to each combination and all piglets received 0.4 mg/kg meloxicam. Subsequently a dosage algorithm for the main trial was developed. In case of insufficient analgesia, lidocaine 2% (0.25 ml) was injected intratesticular. If two piglets showed an insufficient anaesthetic induction phase, depth of anaesthesia or recovery, the next dosage in the algorithm was tried. With the combination of 3 mg/kg azaperone, 0.2 mg/kg romifidine, 15 mg/kg ketamine and 0.2 mg/kg butorphanol the requirement of a smooth anaesthesia induction, sufficient anaesthesia and a recovery without excitation was fulfilled but the recovery lasted more than 120 minutes.

INTRODUCTION: Le but de la présente étude était de mettre au point une combinaison d'anesthésiques injectables par voie intra-musculaire pour les porcelets âgés de 8 à 14 jours qui garantisse une induction calme, une qualité d'anesthésie suffisante (sans mouvement de défense durant l'intervention) et une phase de réveil dépourvue d'excitation et ne durant pas plus de deux heures. Dans le cadre d'un essai préliminaire, on a comparé, afin de définir les doses respectives, des combinaisons de kétamine, d'azapérone et de romifidine. Les résultats ont servi de base pour l'algorithme de dosage de l'essai principal. Les dosages testés étaient les suivants : 1, 2 ou 3 mg/kg d'azapérone, 10 ou 15 mg/kg de kétamine et 0.15 ou 0.2 mg/kg de romifidine. En outre, tous les animaux recevaient du méloxicam (0.4 mg/kg) et du butorphanol (0.2 mg/kg) IM. En cas d'analgésie insuffisante, de la lidocaïne 2% (0.25 ml) était appliquée en intra-testiculaire. Si deux porcelets montraient une phase d'induction, de castration ou de réveil insuffisante, on passait au dosage suivant. Avec la combinaison de 3 mg/kg d'azapérone, 0.2 mg/kg de romifidine, 15 mg/kg de kétamine et de 0.2 mg/kg de butorphanol, les exigences d'une induction calme, d'une qualité d'anesthésie suffisante et d'un réveil dépourvu d'excitation étaient remplies. Toutefois les porcelets dormaient plus de 120 minutes.

Local mepivacaine before castration of horses under medetomidine isoflurane balanced anaesthesia is effective to reduce perioperative nociception and cytokine release.

BACKGROUND: In horses castration with primary intention healing is usually performed under balanced inhalation anaesthesia. To optimise analgesia, the use of local anaesthesia was tested. OBJECTIVES: To investigate the effect of local mepivacaine before castration with first intention healing under balanced medetomidine-isoflurane anaesthesia and flunixin meglumine, morphine analgesia on perioperative cytokine levels and pain in horses. STUDY DESIGN: Prospective blinded clinical study. METHODS: Twenty stallions were randomly assigned to control or mepivacaine groups. Flunixin meglumine was administered before sedation with medetomidine and followed by ketamine/diazepam intravenously (i.v.). Anaesthesia was maintained with isoflurane and 3.5 µg/kg per hour medetomidine. Mepivacaine horses were given mepivacaine 2% (3.5 mL SC, 1 mL/100 kg intrafunicularly, 2 mL/100 kg intratesticularly) on each side. For recovery, horses were given 2 µg/kg medetomidine i.v. and 0.1 mg/kg morphine i.m. and oral phenylbutazone (0.02 mg/kg q12h) for post-operative analgesia. One hour before premedication and 4, 8 and 24 h post-incision, pain was scored with three different pain scales (Equine Utrecht University Scale for Facial Assessment of Pain, Horse Grimace Scale, Equine Utrecht University Scale for Composite Pain Assessment) and plasma cytokines (interleukin-6 and tumour necrosis factor alpha) were measured. Data were analysed using repeated measures ANOVA, linear regression and unpaired t-test, significance level P≤0.05. RESULTS: Horses in both groups showed a significant increase in pain scores and cytokines compared to baseline. Post-operatively the mepivacaine group exhibited significantly lower pain scores and cytokine levels. Mean heart rate during anaesthesia was significantly lower in the mepivacaine group compared to control group (28.8 ± 1 and 33.2 ± 1.7 respectively). Otherwise there were no differences between the groups. MAIN LIMITATIONS: The decision to provide additional analgesia was based on the attending surgeon's assessment rather than a standardised rescue analgesia plan based on pain scores. The study was only conducted for 24 h post-castration and complications were not recorded. CONCLUSION: Local mepivacaine before castration with primary wound closure improved anaesthesia quality, attenuated post-operative increases in cytokines and reduced post-operative pain despite balanced anaesthesia with multimodal analgesia in control horses.

Evaluation of different dose rate combinations of ketamine, romifidine and azaperone for castration of 3-4 and 5-6 weeks old piglets.

INTRODUCTION: In this study dose rate combinations of ketamine, azaperone and romifidine were tested in 3-4 (G3-4) and 5-6 weeks (G5-6) old piglets according to a dose rate decision tree (DRT) to provide calm anaesthesia induction, reaction-free anaesthesia for castration and smooth recovery within 2 hours. When a combination failed to meet those criteria in 2 piglets, the next dosage of the DRT was tested. In G3-4 four combinations were tested in 14 piglets with dose rates of 10-20 mg/kg ketamine, 3 mg/kg azaperone and 0.15-0.20 mg/kg romifidine IM. Induction was smooth in all piglets, but depth of anaesthesia or recovery (11 and 6 piglets) were insufficient. In G5-6 five combinations were tested in 37 piglets with dose rates of 10-20 mg/kg ketamine, 3-4 mg/kg azaperone and 0.15-0.20 mg/kg romifidine IM. Induction was smooth in all piglets but 2. Depth of anaesthesia or recovery (17 and 7 piglets, respectively) were insufficient. In the present study with 3-4 and 5-6 weeks old piglets, acceptable quality of anaesthesia could not be achieved despite using high drug dose rates.

INTRODUCTION: Des combinaisons de doses de kétamine, azapérone et romifidine ont été testées sur la base d'un arbre de décision de dose afin de définir la dose qui assurait, chez des porcelets de 3-4 (G3-4) et de 5-6 (G5-6) semaines une induction tranquille, une anesthésie sans réaction lors de la castration et une phase de réveil calme, terminée en deux heures. Lorsqu'une combinaison de ces critères n'était pas obtenue chez 2 porcelets, on passait à la dose suivante proposée par l'arbre de décision. Dans le G3-4, 4 combinaisons avec des doses de 10-20 mg/kg de kétamine, 3 mg/kg d'azapérone et 0.15-0.20 mg/kg de romifidine IM ont été testées chez 14 porcelets. L'induction était calme chez tous les porcelets mais la profondeur de l'anesthésie ou la phase de réveil étaient insuffisantes chez 11 respectivement 6 porcelets. Dans le G5-6, 5 combinaisons avec des doses de 10-20 mg/kg de kétamine, 3-4 mg/kg d'azapérone et 0.15-0.20 mg/kg de romifidine IM ont été testées chez 37 porcelets. L'induction était calme à deux exceptions près mais la profondeur de l'anesthésie ou la phase de réveil étaient insuffisantes chez 17 respectivement 7 porcelets. Lors de la présente étude, il n'a pas été possible, malgré l'utilisation de doses élevées, d'obtenir chez des porcelets de 3-4 respectivement de 5-6 semaines une qualité d'anesthésie acceptable.

Femoral and sciatic nerve blockades and incision site infiltration in rabbits undergoing stifle joint arthrotomy.

This study was designed to determine whether perineural injections of local anaesthetics decreases intraoperative nociception and improves postoperative analgesia in New Zealand White rabbits undergoing experimental stifle arthrotomy. All animals were anaesthetized using isoflurane and received morphine intramuscularly. The sciatic and femoral nerves of the leg to be operated on were located using a nerve stimulator (1 Hz, 0.5 mA). Rabbits were assigned to a treatment group (LB; n = 12) or a placebo group (P; n = 12) in a randomized blinded fashion. Group LB received lidocaine 2% (1 mg/kg) combined with bupivacaine 0.5% (0.25 mg/kg) injections around the sciatic and femoral nerves (0.1 mL/kg total volume per site) and subcutaneous infiltration of the incision site with lidocaine 1% (1.25 mg/kg). Group P received the same volume of 0.9% NaCl. Rabbits in group P required higher doses of intraoperative fentanyl and propofol to reduce heart rate and suppress increase in systolic blood pressure, and maintain an adequate anaesthetic plane. Interventional analgesia (buprenorphine and carprofen) was required significantly earlier in rabbits in group P (2 and 6 h after the first nerve blockade, respectively) based on assessment of their pain-related behaviour and range of motion. Using a visual analogue scale (0 mm= no pain to 100 mm= maximal possible pain), rabbits in group LB were judged to show significantly less pain compared with rabbits in group P (14 ± 10 mm and 37 ± 25 mm, respectively) 2 h after nerve blockade. In conclusion, this technique of perineural analgesia combined with incision site infiltration reduced intraoperative fentanyl requirements and improved postoperative analgesia in rabbits.

Effects of 10% hydroxyethyl starch (HES 200/0.5) solution in intraoperative fluid therapy management of horses undergoing elective surgical procedures.

The aim of the present study was to investigate the effect of pentastarch on colloid osmotic pressure (COP) and cardiopulmonary function during and up to 24 h after anaesthesia in horses. Twenty-five systemically healthy horses were anaesthetised using isoflurane-medetomidine balanced anaesthesia. Twelve were assigned to treatment with hydroxyethyl starch (HES) (H group) and 13 to no HES (NH group). In the H group, 6 mL/kg of pentastarch 10% HES (200/0.5) was infused over 1 h starting 30 min after induction of anaesthesia. Horses of the NH group received an equal amount of lactated Ringer's solution (LRS). COP and blood biochemical, cardiopulmonary and anaesthesia-related variables were measured at different time points before and after treatment. Pentastarch was effective in correcting the decrease in COP observed with LRS administration. No differences between treatments were detected for blood glucose, lactate, total proteins and electrolytes. Packed cell volume was lower with the H group immediately after finishing HES-administration and for an additional 30 min. In all horses, all blood biochemical variables other than lactate returned to normal after 12 h. No clinically relevant differences between treatments were detected for cardiopulmonary variables, although 23.1% of the NH-horses needed rescue-HES to maintain cardiovascular function, while none of the H-horses needed additional colloids. Overall, 6 mL/kg HES (200/0.5) was found to be effective in maintaining COP during anaesthesia in systemically healthy horses. Intermediate and long-term effects were below the limit of detection. The potentially beneficial effects on cardiovascular function need further investigation, especially in critically ill horses.

Comparison of a new metamizole formulation and carprofen for extended post-operative analgesia in dogs undergoing ovariohysterectomy.

A newly developed slow-release tablet formulation of metamizole was compared with carprofen for post-operative analgesia in dogs undergoing ovariohysterectomy. Twenty-three dogs were randomly assigned to one of two groups, and administered 50 mg/kg metamizole PO (Group M) or 4 mg/kg carprofen PO (Group C) 1 h before anaesthetic induction and 24 and 48 h later. Anaesthesia was induced with propofol and maintained with isoflurane and fentanyl, after premedication with 0.005 mg/kg medetomidine and 0.3 mg/kg methadone IM. A blinded observer assessed post-operative sedation, and analgesia using a visual analogue scale, a dynamic interactive visual analogue scale, the Glasgow composite pain scale (GCPS), and a mechanical nociceptive threshold device (T = 0.5, 1, 2, 4, 8, 12, 18, 21, 24, 36, 45, 60 and 70 h after surgery). Rescue methadone was administered if the GCPS was >6/24 in ambulatory dogs, or >5/20 in non-ambulatory dogs. Plasma concentrations of test drugs were quantified. The dose range for metamizole was 39-56 mg/kg. At T = 0.5 h sedation scores were significantly higher in Group C and GCPS scores were significantly higher in Group M. Three dogs required rescue methadone (Group M, n = 1; Group C, n = 2). Vomiting occurred post-operatively in 45% of dogs in Group M. Carprofen and metamizole were both well absorbed; peak concentrations occurred within 4-24 h, and 4-16 h for carprofen and metamizole, respectively. Both drugs provided adequate analgesia of similar duration. No side effects were observed with carprofen while vomiting was frequent following administration of metamizole.

International online survey to assess current practice in equine anaesthesia.

REASONS FOR PERFORMING STUDY: Multicentre Confidential Enquiries into Perioperative Equine Fatalities (CEPEF) have not been conducted since the initial CEPEF Phases 1-3, 20 years ago. OBJECTIVES: To collect data on current practice in equine anaesthesia and to recruit participants for CEPEF-4. STUDY DESIGN: Online questionnaire survey. METHODS: An online questionnaire was prepared and the link distributed internationally to veterinarians possibly performing equine anaesthesia, using emails, posters, flyers and an editorial. The questionnaire included 52 closed, semiclosed and open questions divided into 8 subgroups: demographic data, anaesthetist, anaesthesia management (preoperative, technical equipment, monitoring, drugs, recovery), areas of improvements and risks and motivation for participation in CEPEF-4. Descriptive statistics and Chi-squared tests for comparison of categorical variables were performed. RESULTS: A total of 199 questionnaires were completed by veterinarians from 14 different countries. Of the respondents, 43% worked in private hospitals, 36% in private practices and 21% in university teaching hospitals. In 40 institutions (23%) there was at least one diplomate of the European or American colleges of veterinary anaesthesia and analgesia on staff. Individual respondents reported routinely employ the following anaesthesia monitoring modalities: electrocardiography (80%), invasive arterial blood pressures (70%), pulse oximetry (60%), capnography (55%), arterial blood gases (47%), composition of inspired and expired gases (45%) and body temperature (35%). Drugs administered frequently or routinely as part of a standard protocol were: acepromazine (44%), xylazine (68%), butorphanol (59%), ketamine (96%), diazepam (83%), isoflurane (76%), dobutamine (46%), and, as a nonsteroidal anti-inflammatory drug, phenylbutazone (73%) or flunixin meglumine (66%). Recovery was routinely assisted by 40%. The main factors perceived by the respondents to affect outcome of equine anaesthesia were the preoperative health status of the animal and training of the anaesthetist. CONCLUSIONS: Current practice in equine anaesthesia varies widely, and the study has highlighted important topics relevant for designing a future prospective multicentre cohort study (CEPEF-4). The Summary is available in Chinese - see Supporting information.

Incidence of delayed hair re-growth, pruritus, and urinary retention after epidural anaesthesia in dogs.

OBJECTIVE: Delayed hair re-growth, pruritus and urinary retention are known complications after epidural anaesthesia in dogs. The aim of this study was to prospectively evaluate the effect of epidurally administered drugs on the occurrence of these complications in dogs. MATERIAL AND METHODS: Ninety dogs were included in this study. Eighty client-owned dogs undergoing surgery were randomly assigned to one of three epidural treatment groups: either morphine and bupivacaine (MB), bupivacaine (B), or saline solution 0.9% (S) was administered epidurally to these patients. Ten dogs were only clipped in the lumbosacral area (C). Follow-up started 4 weeks after clipping and was performed every 4-5 weeks in cases of delayed hair re-growth or pruritus. Hair re-growth in the lumbosacral area was observed and compared to hair re-growth in the surgical field and the fentanyl patch area. Cytological analysis and a trichogram were performed if hair re-growth was delayed after 6 months. Time interval to first urination postoperatively was recorded (n = 80). RESULTS: Hair re-growth was delayed in 11 dogs (12.2%; B: n = 7, S: n = 2, MB: n = 1, C: n = 1) with no differences between groups. Pruritus was evident in two dogs (2.2%; MB: n = 1, S: n = 1). After 6 months, hair had started to re-grow in all but one dog (B). After 10 months the coat of this dog had re-grown. Time to first urination did not differ between groups. CONCLUSION AND CLINICAL RELEVANCE: No direct correlation between the particular drugs injected epidurally and delayed hair re-growth, pruritus and urinary retention could be shown. Dog owners should be informed that hair re-growth after epidural anaesthesia could be markedly delayed.

Racemic ketamine in comparison to S-ketamine in combination with azaperone and butorphanol for castration of pigs.

In this prospective blinded randomised study, 28 male 9 week old pigs of bodyweight 25 kg, were anaesthetised for castration using 5 mg/kg azaperone, 0.2 mg/kg butorphanol and 0.4 mg/kg meloxicam, in conjunction with either 15 mg/kg racemic ketamine (Keta-Race) or 9 mg/kg S-ketamine (S-Keta), all drugs being injected intramuscularly. Anaesthesia induction, maintenance and recovery were timed and scored. Insufficient anaesthesia was supplemented with » the initial dose of ketamine or S-ketamine, respectively, administered intravenously. A t-test was utilised for analysis of timings, and, for repeated recovery time data, ANOVA was used. In relation to quantification and timing of supplemental drug doses, a chi square test was used and the scoring was analysed by two sample Wilcoxon rank-sum test. Ketamine re-dosing was required in 23 animals on a total of 46 occasions distributed evenly throughout both groups. The only group differences occurred during recovery, with the S-Keta group showing earlier movements, sternal recumbency and ability to stand. Three pigs in each group showed muscle fasciculations during the recovery period, while an additional two animals of the Keta-Race group exhibited marked and unacceptable paddling in recovery. In conclusion, S-ketamine at a dose rate of 60 % of that of racemic ketamine induced comparable anaesthesia for castration in pigs, but with superior recovery characteristics.

Pour cette étude prospective, randomisée et en aveugle, on a castré 28 porcs mâles âgés de 9 semaines et d'un poids estimé de 25 kg en utilisant soit 15 mg/kg de kétamine racémique soit 9 mg/kg de S-kétamine, en combinaison avec 5mg/kg d'azaperon, 0.2 mg/kg de butorphanol et 0.4 mg/kg de meloxicam, administrés par voie intramusculaire. L'induction et l'anesthésie elle-même ainsi que la phase de réveil ont été estimées qualitativement et leurs durées mesurées. Si la profondeur de l'anesthésie était insuffisante, on a injecté par voie intraveineuse » de la dose initiale de kétamine. On a estimé les durées par T-test et ANOVA et la qualité de l'anesthésie par «two sample Wilcoxon rank-sum test¼. Chez 23 animaux, il a été nécessaire de rajouter 46 fois de la kétamine (de façon égale dans les deux groupes). Les seules différences entre les deux groupes ont été observées lors de la phase de réveil. Avec la S-kétamine, on observe plus rapidement des mouvements, une position sternale et un relevé. Trois animaux de chaque groupe ont présenté des fasciculations musculaires et deux, après application de kétamine racémique, des mouvements de pédalage importants durant la phase de réveil. En résumé, l'application de S-kétamine à un dosage correspondant à 60% de celui de la kétamine racémique produit une anesthésie similaire. Aucun des porcs anesthésies avec de la S-kétamine n'a montré une phase de réveil inacceptable.

Blood glucose, acid-base and electrolyte changes during loading doses of alpha2-adrenergic agonists followed by constant rate infusions in horses.

The aim of the present study was to investigate changes in blood glucose concentration ([Glu]B), acid-base status and electrolyte concentrations during constant rate infusions (CRI) of two alpha2-adrenergic agonists in seven horses treated in a blinded, randomised, crossover design with xylazine or romifidine. An intravenous (IV) bolus of xylazine (1mg/kg) or romifidine (80 µg/kg) was administered followed by an IV CRI of xylazine (0.69 mg/kg/h) or romifidine (30 µg/kg/h) for 2h. Blood samples were collected from the pulmonary artery before and after loading doses, during the CRI, and for 1h after discontinuing drugs. Blood glucose, base excess (BE), pH, partial pressure of carbon dioxide (Pv¯CO2), strong ion difference (SIDest) and bicarbonate concentration ( [Formula: see text] ) increased significantly during the CRI with both alpha2-adrenergic agonists. Chloride concentration ([Cl(-)]B) and anion-gap (AG) decreased significantly compared to baseline. The decrease in sodium concentration ([Na(+)]B) was only significant with xylazine. From 1h after starting the CRI onwards, [Glu]B was significantly higher with romifidine compared to xylazine. Except [Glu]B, SIDest, and Pv¯CO2, all variables returned to normal values 1h after discontinuing xylazine. After stopping romifidine, all variables except pH remained altered for at least 1h. It was concluded that loading doses of alpha2-adrenergic agonists followed by CRIs produce [Glu]B, acid-base and electrolyte changes. The clinical significance of the reported changes remains to be investigated and absolute values should be interpreted with caution, as fluid boli were used for cardiac output measurements, but may become important during prolonged infusion and in critically ill patients.

[Bupivacaine toxicity and propofol anesthesia : animal study on intravascular bupivacaine injection]. / Bupivacaintoxizität und Propofolanästhesie : Tierstudie zur intravasalen Bupivacaininjektion.

BACKGROUND: Several reports have confirmed the efficacy of Intralipid® (containing soya bean oil, egg phospholipids, glycerin and water) in the therapy of systemic local anesthetic intoxication. Pretreatment with Intralipid® shifted the dose-response to bupivacaine-induced asystole in rats. Whether intravenous anesthesia with propofol in the widely used medium chain triglyceride lipid emulsion increases the therapeutic range of systemically administered bupivacaine or not is unknown and was investigated in this study. METHODS: A total of 30 piglets aged 2-6 weeks and weighing 4.5-6.5 kg were randomized into 2 groups and anesthetized with sevoflurane (group S) alone or with propofol 10 mg/kg body weight (BW)/h plus sevoflurane (group PS). After 60 min of steady state anesthesia arterial blood was sampled for assessment of blood gases, acid-base state and triglyceride plasma concentrations. Thereafter bupivacaine 0.125% was continuously infused by an infusion syringe pump through a central venous line at a rate of 4 mg/kg BW/min until invasively measured mean arterial pressure (MAP) was reduced by 50% of initial value. The bupivacaine infusion was stopped, blood for assessment of bupivacaine plasma concentration was drawn and the spontaneous hemodynamic course was observed. Resuscitation was not attempted. Results are presented as median and range. The Mann-Whitney U-test was used to assess differences between the two groups for triglyceride as well as for bupivacaine plasma concentrations measured at MAP 50%. A p-value≤0.05 was considered to be significant. RESULTS: Baseline conditions (arterial blood pH, plasma protein and triglyceride plasma concentrations) did not differ significantly between the two groups. After 1 h of anesthesia, triglyceride plasma concentrations were significantly increased in group PS (median 0.69 mmol/l) compared to the corresponding baseline values (median 0.14 mmol/l; p<0.001) and to the 1 h values of group S (median 0.16 mmol/l; p<0.001). The total amount of bupivacaine administered was 9 mg/kg BW in both groups (6-13 mg/kg BW in group S, 5-13 mg/kg BW in group PS). Resulting bupivacaine plasma concentrations were 180 µmol/l (83-686 µmol/l) in group S and 185 µmol/l (130-465 µmol/l) in group PS. However, the total amount of bupivacaine administered and bupivacaine plasma concentrations at MAP 50% did not reveal statistically significant differences between the two groups but a huge variability of both parameters within each group was observed. None of the 30 piglets spontaneously recovered and they died from pulseless electrical activity or from asystolic cardiac arrest. The time from MAP 50% until cardiac arrest demonstrated a large variability but did not reveal significant differences between the two groups. The time to cardiac arrest was similar in both groups. CONCLUSION: Medium/long chain triglyceride lipid emulsion (50:50) as widely used in propofol solutions did not increase therapeutic safety in cases of intravascular bupivacaine administration in this piglet model.