Anestesia balanceada em gato palheiro (Leopardus braccatus) para realização de gastrotomia e enterotomia ­ relato de caso / Balanced anesthesia in pamps cat (Leopardus braccatus) for gastrotomy and enterotomy ­ case report / Anestesia balanceada en gato palheiro (Leopardus braccatus) para gastrotomía y enterotomía ­ reporte de caso

Foi atendido no Hospital Veterinária da Universidade Federal de Mato Grosso (HOVET-UFMT) - Campus Cuiabá, um gato palheiro (Leopardus braccatus), macho, filhote e pesando 1,8kg. Após avaliação clínica e exames complementares diagnosticou-se presença de corpo estranho solido gástrico e intestinal. Como medicação pré-anestésica optou-se pela associação de cetamina (1mg/kg) e midazolam (0,2mg/kg), seguiu-se com a indução com propofol (à efeito) e manutenção anestésica por meio do fornecimento de isofluorano. Como técnica adicional utilizou-se epidural, com uma associação de lidocaína (4,5mg/kg) e morfina (0,1mg/kg). Durante o procedimento anestésico notou-se estabilidade das variáveis cardiovasculares e respiratórias, além de recuperação satisfatória ao final do procedimento.

Was attended to in the Veterinary Hospital of the Federal University of Mato Grosso (HOVET-UFMT) - Campus Cuiabá, a pantanal cat (Leopardus braccatus), male, puppy and weighing 1.8 kg. After clinical evaluation and complementary exams, the presence of a solid gastric and intestinal foreign body was diagnosed. As pre-anesthetic medication, the association of ketamine (1mg/kg) and midazolam (0.2mg/kg) was chosen, followed by induction with propofol (for effect) and anesthetic maintenance by supplying isoflurane. As an additional technique, an epidural was used, with an association of lidocaine (4.5mg/kg) and morphine (0.1mg/kg). During the anesthetic procedure, stability of cardiovascular and respiratory variables was observed, in addition to satisfactory recovery at the end of the procedure.

Ingresó en el Hospital Veterinario de la Universidad Federal de Mato Grosso (HOVET-UFMT) · Campus Cuiabá, un gato palheiro (Leopardus braccatus), macho, cachorro y con un peso de 1,8 kg. Luego de evaluación clínica y exámenes complementarios se diagnosticó la presencia de cuerpo extraño sólido gástrico e intestinal. Como medicación preanestésica se optó por la asociación de ketamina (1 mg/kg) y midazolam (0,2 mg/kg), seguida de inducción con propofol (por efecto) y mantenimiento anestésico mediante suministro de isoflurano. Como técnica adicional se utilizó epidural, con asociación de lidocaína (4,5 mg/kg) y morfina (0,1 mg/kg). Durante el procedimiento anestésico se observó estabilidad de variables cardiovasculares y respiratorias, además de recuperación satisfactoria al final del procedimiento.

Use of dexmedetomidine repeated subcutaneous administration for balanced anaesthesia in horses.

BACKGROUND: A balanced anaesthetic protocol is a common concept in modern veterinary anaesthesia and aims to maintain good intraoperative cardiopulmonary function. In horses, alpha-2-agonists produce sedation and analgesia and have been shown to reduce inhalational anaesthetic requirements when administered intravenously. Furthermore, these drugs can improve recovery quality. Preliminary investigations of subcutaneous dexmedetomidine administration in humans demonstrated a reduced haemodynamic impact if compared with the intravenous route suggesting that dexmedetomidine is adequately absorbed with both administration routes. The aim of the study was to compare two different dexmedetomidine (DEX) administration routes: intravenous constant rate infusion (CRI) versus repeated subcutaneous (SC) injections on cardiopulmonary function and recovery in anaesthetized horses. RESULTS: No significant differences between groups in heart rate and systolic arterial pressure were detected. A significantly higher mean and diastolic arterial pressure were detected in the SC group at T25 (p = 0.04; p = 0.02), T75 (p = 0.02; p = 0.009), and T85 (p = 0.001; p = 0.005). In SC group there was a significantly lower dobutamine infusion rate (p = 0.03) and a significantly higher urinary output (p = 0.02). Moreover, recovery quality was higher (p = 0.01). CONCLUSIONS: Cardiopulmonary effects in both groups were comparable and within clinical ranges with less dobutamine requirement in the subcutaneous group. Recovery was of better quality with fewer attempts in horses receiving subcutaneous dexmedetomidine. The present study suggests that intravenous constant rate infusion and subcutaneous repeated administration of dexmedetomidine at indicated dosage can be useful in balanced anaesthesia without any systemic or local adverse effects; moreover, in healthy horses undergoing general anaesthesia, repeated subcutaneous dexmedetomidine administration may be a suitable alternative if constant rate infusion is not feasible.

Anestesia geral inalatória ou total intravenosa associada à anestesia subaracnoidea, em ovinos / General inhalation anesthesia or total intravenous associated with subarachnoid anesthesia in sheep

Avaliou-se a eficácia e a segurança anestésica em ovinos mantidos sob anestesia geral inalatória com isofluorano ou anestesia total intravenosa com propofol, ambas associadas à anestesia subaracnoidea. Quatorze ovinos foram pré-medicados com 0,3mg.kg-1 de morfina IM, e cinco minutos após, receberam 20mcg.kg-1 de detomidina IV. Posteriormente, foram alocados aleatoriamente em dois grupos: GISO (n=7), os quais foram induzidos à anestesia geral com 0,5mg.kg-1 de diazepam e 5mg.kg-1 de cetamina IV, e mantidos em anestesia geral inalatória com isoflurano diluído em oxigênio a 100%; e GPRO (n=7), induzidos com 4mg.kg-1 de propofol IV seguido inicialmente de infusão contínua na taxa de 0,3mg.kg-1.min-1. Para realização da osteotomia bilateral, todos os animais receberam 0,5mg.kg-1 de ropivacaína 0,75% associado a 0,1mg.kg-1 de morfina pela via subaracnoidea. Houve redução de 40% nos valores médios de frequência cardíaca após sedação em ambos os grupos, permanecendo em média 23% reduzida até o final da avaliação. A pressão arterial média aumentou 16%, após a indução anestésica no GISO, mas se reduziu até o final do procedimento, assim como no GPRO. A EtISO média foi de 0,57V% e a taxa média de infusão do propofol foi de 0,24mg.kg-1.min-1. Os tempos totais de cirurgia, anestesia e extubação foram de 66±9,8, 92±13,8 e 7,0±1,5 minutos no GISO e 56±2,4, 82,9±4,6 e 5,4±1,5 minutos no GPRO, não havendo diferença significativa entre grupos. A manutenção anestésica com isoflurano ou propofol promoveu plano anestésico similar com mínimos efeitos cardiovasculares ou hemogasométricos, que são bem tolerados em ovinos hígidos.

The purpose of this study was to evaluate the efficacy and safety of sheep submitted to inhalation anesthesia with isoflurane or total intravenous anesthesia with propofol, both associated with subarachnoid anesthesia. Fourteen animals were pre-medicated with 0.3mg.kg-1 morphine IM, and 5 minutes later received 20mcg.kg-1 detomidine IV. Then they were allocated into two groups: GISO (n=7), which were induced with 0.5mg.kg-1 of diazepam and 5mg.kg-1 of ketamine IV, and anesthesia maintenance was performed by isoflurane diluted in 100% oxygen; or GPRO (n=7), where animals were induced with 4mg.kg-1 propofol IV and subsequent maintenance anesthesia with its own infusion of 0.3mg.kg.min-1. To perform the bilateral tibial osteotomy, all animals received 0.5mg.kg-1 0.75% ropivacaine combined with 0.1mg.kg-1 morphine by the intrathecal route. There was a 40% reduction in mean heart rate after the sedative protocol in both groups, resulting in a 23% average reduction until the end of the review. Mean arterial pressure showed transient elevation of around 16%, after induction of anesthesia in GISO, but reducing it to the end of the procedure, as well as in GPRO. The average EtISO was 0.57 V% and average infusion rate of propofol was 0.24mg.kg-1.min-1. The total time of surgery, anesthesia and extubation was 66± 9.8, 92±7.0 and 13.8±1.5 minutes in GISO and 56±2.4, 82.9±4.6 and 5.4±1.5 minutes in GPRO. The maintenance of anesthesia with propofol or isoflurane produced similar anesthesia with minimal cardiovascular and blood gas effects, which are well tolerated in healthy sheep.

Effects of lidocaine administration via continuous rate infusion on the minimum alveolar concentration of isoflurane in New Zealand White rabbits (Oryctolagus cuniculus).

OBJECTIVE: To evaluate the effect of a continuous rate infusion (CRI) of lidocaine on the minimum alveolar concentration (MAC) of isoflurane in rabbits. ANIMALS: Five 12-month-old female New Zealand White rabbits (Oryctolagus cuniculus). PROCEDURES: Rabbits were anesthetized with isoflurane. Baseline isoflurane MAC was determined by use of the tail clamp technique. A loading dose of lidocaine (2.0 mg/kg, IV) was administered followed by a CRI of lidocaine at 50 µg/kg/min. After 30 minutes, isoflurane MAC was determined. Another loading dose was administered, and the lidocaine CRI then was increased to 100 µg/kg/min. After 30 minutes, isoflurane MAC was determined again. Plasma samples were obtained for lidocaine analysis after each MAC determination. RESULTS: Baseline isoflurane MAC was 2.09%, which was similar to previously reported values in this species. Lidocaine CRI at 50 and 100 µg/kg/min induced significant reductions in MAC. The 50 µg/kg/min CRI resulted in a mean plasma lidocaine concentration of 0.654 µg/mL and reduction of MAC by 10.5%. The 100 µg/kg/min CRI of lidocaine resulted in a mean plasma concentration of 1.578 µg/mL and reduction of MAC by 21.7%. Lidocaine also induced significant decreases in arterial blood pressure and heart rate. All cardiopulmonary variables were within reference ranges for rabbits anesthetized with inhalation anesthetics. No adverse effects were detected; all rabbits had an uncomplicated recovery from anesthesia. CONCLUSIONS AND CLINICAL RELEVANCE: Lidocaine administered as a CRI at 50 and 100 µg/kg/min decreased isoflurane MAC in rabbits. The IV administration of lidocaine may be a useful adjunct in anesthesia of rabbits.

Balanced anesthesia and constant-rate infusions in horses.

Balanced anesthetic techniques are commonly used in equine patients, and include the combination of a volatile anesthetic with at least one injectable anesthetic throughout the maintenance period. Injectable anesthetics used in balanced anesthesia include the α2-agonists, lidocaine, ketamine, and opioids, and those with muscle-relaxant properties such as benzodiazepines and guaifenesin. Administration of these injectable anesthetics is best using constant-rate infusions based on the pharmacokinetics of the drug, which allows steady-state concentrations and predictable pharmacodynamic actions. This review summarizes the different drug combinations used in horses, and provides calculated recommended doses based on the pharmacokinetics of individual drugs.

Efeitos da associação de tiletamina/zolazepam ou cetamina S(+)/midazolam/tramadol para contenção química em bugios-ruivos (Allouatta guariba clamitans) / Effects of tiletamine/zolazepam or S(+) ketamine/midazolam/tramadol for chemical contention in red howler monkeys (Allouatta guariba clamitans)

Two protocols for chemical restraint in howler-redheads were evaluated. We used 12 healthy red howler monkeys, weighing 6.4±0.4 kg, which were fasted and without water six and two hours, respectively. The animals were divided into two groups that received intramuscular injection: TZ (n=6) which received tiletamine-zolazepam (Zoletil®) at a dose of 3.6mg/kg and CEMTRA (n=6) which received ketamine S (+), tramadol and midazolan (Cemtra®, pilot batch 001/10, Ouro Fino Saúde Animal Ltda, Cravinhos/SP, Brazil, comprising 100mg/ml of ketamine S (+), tramadol 20mg/ml and 10mg/ml of midazolam) in dose of 1ml of the association for each 10kg of body weight, equivalent doses of 10mg/kg, 1mg/kg and 2mg/kg, respectively. Prior to administration of drugs (M0) were evaluated: heart rate (HR), respiratory rate (RR), rectal temperature (RT), capillary refill time (CRT), systolic arterial pressure (SAP), hemoglobin oxygen saturation (SpO2 ), presence of salivation, degree of muscle relaxation and sedation, Bispectral index (BIS) and Signal Quality BIS (SQI), interdigital pinch response and latency times, ambulation and total recovery (TRT). The parameters were reassessed M5, M10, M20, M30, M40 and M50 (5, 10, 20, 30, 40 and 50 minutes after drug administration). In TZ animals were more responsive to the interdigital pinch over time. The animals of CEMTRA showed a higher degree of muscle relaxation and sedation. The RR of CEMTRA was lower after administration of treatment at all times in relation to M0. Among the groups RR of CEMTRA was lower compared to the TZ in M2 and M4. The total time of sedation and recovery was 48±4 min and 150.1±42.1 for the CEMTRA and 38±7 and 73.1±20.6 for the TZ. We conclude that both formulations are safe for containing chemical howler, and the CEMTRA showed better sedation and muscle relaxant.

Avaliaram-se dois protocolos para contenção química em bugios-ruivos. Para tal, foram utilizados 12 macacos bugios, hígidos, com peso médio de 6,4±0,4 kg, os quais foram submetidos a jejum alimentar e hídrico de seis e duas horas, respectivamente. Os animais foram alocados em dois grupos que receberam injeção via intramuscular: TZ (n=6), os quais receberam uma associação de tiletamina e zolazepam (Zoletil®) na dose de 3,6mg/kg e CEMTRA (n=6), que receberam cetamina S(+), midazolam e tramadol (Cemtra ®, lote piloto 001/10, Ouro Fino Saúde Animal Ltda., Cravinhos, SP-Brasil, constituído por 100mg/ml de cetamina S+, 20mg/ml de tramadol e 10mg/ml de midazolam) na dose de 1ml da associação para cada 10kg de peso corporal, correspondendo às doses de 10mg/kg, 1mg/kg e 2mg/kg, respectivamente. Anteriormente a administração dos fármacos (M0) foram avaliadas: frequência cardíaca (FC) e respiratória (f), temperatura retal (TR), tempo de preenchimento capilar (TPC), pressão arterial sistólica (PAS), saturação de oxigênio na hemoglobina (SpO2), presença de salivação, grau de miorrelaxamento e sedação, índice Bispectral (BIS) e Sinal de Qualidade do BIS (SQI), resposta ao pinçamento interdigital e tempos de latência, deambulação e de recuperação total (TRT). Os parâmetros foram reavaliados em M5, M10, M20, M30, M40 e M50 (5, 10, 20, 30, 40 e 50 minutos após a administração dos fármacos). No TZ os animais foram mais responsivos ao pinçamento interdigital ao longo dos tempos. Os animais do CEMTRA apresentaram maior grau de miorrelaxamento e de sedação. A f do CEMTRA foi menor após a administração do tratamento em todos os momentos em relação ao M0. Entre grupos a f do CEMTRA foi menor em relação ao TZ em M2 e M4. Os tempos totais de sedação e de recuperação foram de 48±4 e 150,1±42,1 min para o CEMTRA e de 38±7 e 73,1±20,6 para o TZ. Conclui-se que ambas as formulações são seguras para contenção química de bugios, sendo que o CEMTRA apresentou melhor sedação e miorrelaxamento.

Effects of lidocaine constant rate infusion on sevoflurane requirement, autonomic responses, and postoperative analgesia in dogs undergoing ovariectomy under opioid-based balanced anesthesia.

The effects of constant rate infusion (CRI) of lidocaine on sevoflurane (SEVO) requirements, autonomic responses to noxious stimulation, and postoperative pain relief were evaluated in dogs undergoing opioid-based balanced anesthesia. Twenty-four dogs scheduled for elective ovariectomy were randomly assigned to one of four groups: BC, receiving buprenorphine without lidocaine; FC, receiving fentanyl without lidocaine; BL, receiving buprenorphine and lidocaine; FL, receiving fentanyl and lidocaine. Dogs were anesthetized with intravenous (IV) diazepam and ketamine and anesthesia maintained with SEVO in oxygen/air. Lidocaine (2mg/kg plus 50 µg/kg/min) or saline were infused in groups BL/FL and BC/FC, respectively. After initiation of lidocaine or saline CRI IV buprenorphine (0.02 mg/kg) or fentanyl (4 µg/kg plus 8 µg/kg/h CRI) were administered IV in BC/BL and FC/FL, respectively. Respiratory and hemodynamic variables, drug plasma concentrations, and end-tidal SEVO concentrations (E'SEVO) were measured. Behaviors and pain scores were subjectively assessed 1 and 2h post-extubation. Lidocaine CRI produced median drug plasma concentrations <0.4 µg/mL during peak surgical stimulation. Lidocaine produced a 14% decrease in E'SEVO in the BL (P<0.01) but none in the FL group and no change in cardio-pulmonary responses to surgery or postoperative behaviors and pain scores in any group. Thus, depending on the opioid used, supplementing opioid-based balanced anesthesia with lidocaine (50 µg/kg/min) may not have any or only a minor impact on anesthetic outcome in terms of total anesthetic dose, autonomic responses to visceral nociception, and postoperative analgesia.