Fábio Futema

A new brachial plexus block technique in dogs

OBJECTIVEnTo evaluate the feasibility and efficacy of a new technique of brachial plexus anesthesia in dogs.nnnSTUDY DESIGNnProspective, experimental study.nnnANIMALSnTwelve adult mongrel dogs, six males and six females weighing 14.8 ± 1.75 kg.nnnMETHODSnThe animals were sedated with acepromazine 0.05 mg kg-1 and anesthetized with propofol (6 mg kg-1, IV bolus) followed by an infusion of 212 μg kg-1 minute-1. The brachial plexus block technique was performed utilizing the brachial artery as an anatomic landmark, the needle was inserted from the axilla and a nerve stimulator was used to ensure the accuracy of needle placement. Bupivacaine (0.375% with 5 μg mL-1 epinephrine) was used at a dose rate of 4 mg kg-1. Dogs underwent mid-diaphyseal osteotomies of the humerus followed by intramedullary pin fixation.nnnRESULTSnOnset time to motor and sensory block were 9.70 ± 5.52 and 26.20 ± 8.86 minutes, respectively. Analgesia lasted for 11.11 ± 0.47 hours. The block was effective in 91.6% of the animals, being verified by anesthesia of the whole front limb distal to the shoulder. One animal became hypotensive after the block and did not undergo the surgery at that time. In the remaining 10 animals the heart and respiratory rates, blood pressure, blood gas parameters and plasma bicarbonate concentration did not show any statistically significant alterations during the surgical procedure.nnnCONCLUSIONSnThis brachial plexus block technique is effective in most cases to provide surgical analgesia for the front limb distal to the shoulder.nnnCLINICAL RELEVANCEnVarious surgical procedures in the front limb can be performed with a regional anesthetic technique without the use and concomitant risks of general anesthesia in dogs. Long-lasting analgesia associated with this technique may also provide a valuable tool for the management of pain in the forelimb.

Nova técnica de bloqueio do plexo braquial em cães

The aim of this study was to evaluate the viability and efficacy of a new technique of brachial plexus block in dogs. Eleven mongrel dogs of different ages and weight, both male and female were used. Animals were pre-medicated with acepromazine and induction of anesthesia was performed with propofol. The brachial plexus block was achieved with the combination of the following techniques: multiple injections, nerve stimulator and the axilary artery pulse to locate the nerves. Bupivacaine was the local anesthetic employed at a total dose of 4mg/kg. This dose was divided in 4, that were administered in 30 seconds each, to achieve more nerves as possible. The time spent to perform the whole procedure was 11.30 ± 4.54 minutes; onset time for motor and sensitive block were 9.70 ± 5.52 and 26.20 ± 8.86 respectively. Duration of analgesia was 11.0 ± 0.45 hours. The block was effective in 90% of animals what was assessed through complete anesthesia of the front limb distally to the shoulder joint. Hypotension in one animal was the sole complication observed. With the results obtained we can suggest the use of this technique for front limb surgery performed distally to the shoulder joint as well as a pos-operative analgesic approach in dogs.

Avaliação comparativa entre acepromazina, detomidina e romifidina em eqüinos

Farmaceutica, Tecnica de Nivel Superior, FMVZ, USP.RESUMOOs efeitos da acepromazina, detomidina e romifidi-na em equinos foram comparados, objetivando-se determinarqual o agente mais seguro e efetivo para a referida especieanimal. Foram utilizados 15 equinos higidos, de ambos os sexos,idades e racas variadas e encaminhados ao setor de Cirurgia doHospital Veterinario da FMVZ - USP. Os animais foram distri-buidos em tres grupos: grupo I, recebeu 0,1mg/kg de aceproma-zina; grupo II recebeu 20mcg/kg de detomidina e grupo III, oqual recebeu 80mcg/kg de romifidina, sendo todos os agentesadministrados atraves da via intravenosa. Previamente a admi-nistracao dos farmacos e aos 15, 30, 60 e 90 minutos, apos suaaplicacao, foram avaliadas a frequencia e ritmo cardiacos,frequencia respiratoria, pressao arterial sistolica e diastolica,assim como foram coletadas amostras de sangue arterial paraverificacao do pH, pressao parcial de oxigenio e pressao parcialde dioxido de carbono. Os resultados foram submetidos a analiseestatistica atraves do teste de analise de variância (ANOVA),seguido do teste de Tukey. Nao foi observada nenhuma alteracaoda frequencia respiratoria nos grupos estudados. Verificou-sediminuicao significativa dos valores da FC nos animais tratadoscom os agentes α-2 agonistas quando comparados com os valo-res obtidos no grupo I. Apos a administracao da acepromazina,observou-se diminuicao significativa das pressoes sistolica ediastolica em relacao aos valores controle. Os animais do grupoI apresentaram valores pressoricos estatisticamente inferiores emrelacao aos valores obtidos nos grupos II e III. Os animais dogrupo II demonstraram incremento da pressao arterial sistolicaapos 15 minutos da aplicacao do agente, com subsequente redu-cao destes valores. O mesmo ocorreu no grupo III, porem, semvalor estatistico significativo. Com estes resultados, pode-seconcluir que a romifidina e a detomidina promoveram alteracoesparametricas de menor intensidade e duracao quando compara-das a acepromazina.Palavras-chave: acepromazina, romifidina, detomidina, equinos.SUMMARYThe effects of acepromazine, detomidine andromifidine were compared in horses in the present study, aimingto determine which agent is safer and more effective for thereferred species of animal. Fifteen healthy horses of the same sex,age and breed varying, were sent to the Surgical Division of theVeterinarian Hospital of FMVZ-USP. The animals weredistributed in three groups; group I - GI - received 0.1mg/kg ofacepromazine; group II - GII - received 20µg/kg of detomidine;group III - GIII received 80µg/kg of romifidine, all agentsdelivered intravenously. Prior to administration of the agents andat 15, 30, 60 and 90 minutes after their application, the followingparameters were evaluated: heart rate, respiratory rate, systolicand diastolic arterial pressure. Arterial blood samples werecollected to verify pH, partial oxygen pressure and partial carbondioxide pressure. The results were submitted to statisticalanalysis using the analysis of variance (ANOVA) followed by theTukey test. No significant alteration was observed in respiratoryrate of the studied groups. The heart rate significantly decreasedin the animals treated with the alpha-2 agonist agents whencompared to the values obtained in the GI. Followingadministration of acepromazine a significant decrease n systolicand diastolic blood pressures was observed in relation to controlvalues. The animals of GI presented pressure values that werestatistically inferior in relation to the values obtained for groupsII and III. The animals in GII showed an increase in systolic

Utilização de alfentanil, sufentanil e fentanil em cães anestesiados com halotano

Opioid analgesics promote intense analgesia allowing reduction of the concentration of the inhalation anesthetics what minimizes the cardiovascular depression that occurs during anesthesia. Many opioid agents are used during anesthesia. Fentanil, alfentanil and sufentanil are among the most potent agents being preferentially used transoperatively. In the present study, the cardiovascular action of this three agents were compared during inhalation anesthesia in dogs submitted to orthopedic procedures, as well as the possibility of maintenance of anesthesia with halothane in low concentrations. Three groups of ten animals were employed in the experiment. After anesthesia stabilization, animals of group I received intravenously (IV) 5µg/kg of fentanil, animals of group II 1µg/kg of sufentanil IV and animals of group III 25µg/kg of alfentanil IV. Cardiovascular and respiratory parameters were evaluated in various time points. Data were statistically analyzed by means of analyses of variance for repeated measures followed by the Dunnett and Bonferoni post tests.All three agents caused bradicardia during the observation period but only alfentanil promoted significant hypotension. Only one animal that received fentanil showed increase of blood pressure and heart rate simultaneously during anesthesia. At recovery more animals treated with alfentanil showed signs of excitation. With the results obtained the authors could conclude that the use of opioids during anesthesia yield the use of low concentrations of halothane, what contributes with blood pressure maintenance. Among the agents utilized alfentanil promotes more pronounced cardiovascular effects.

Preliminary study of a teaching model for ultrasound-guided peripheral nerve blockade and effects on the learning curve in veterinary anesthesia residents

OBJECTIVEnTo evaluate the use of an experimental colloid model for teaching veterinary anesthesia residents ultrasound-guided technique for nerve blockade.nnnSTUDY DESIGNnProspective, blinded and randomized.nnnMETHODSnColloid models were constructed for practice in ultrasound-guided needle location. Nine veterinary anesthesia residents with no prior experience of ultrasound-guided technique for nerve blocks were randomly divided into three groups. Each group received theoretical orientation. Two groups were assigned to practical training using the experimental model: group 1 (G1) received 2 hours of training and group 2 (G2) received 1 hour of training prior to testing with specific tasks. Group 3 (G3) received no practical training. During testing, the time required for task completion (e.g., display of structures and positioning a needle) and the number of failures were recorded.nnnRESULTSnThe average times to completion of the tasks and the number of technical failures were: G1, 47 seconds and 1 failure; G2, 68 seconds and 2 failures; G3, 187 seconds and 7 failures.nnnCONCLUSIONS AND CLINICAL RELEVANCEnIn residents with no prior experience of ultrasound-guided needle placement, using an experimental colloid model and a longer training period was associated with increased accuracy and decreased time to task completion. Based on the results of this study, training with an experimental model can be recommended to improve the speed and accuracy of needle manipulation using ultrasound in clinicians with no prior experience of ultrasound-guided technique.

Alterações cardiorrespiratórias da anestesia geral em eqüinos com romifidina, tiletamina/zolazepam e halotano

Dez equinos foram submetidos a anestesia com romifidina (80 mg/kg via intravenosa), inducao com a associacao tiletamina/zolazepam (1,1mg/kg em solucao a 5% via intravenosa) e manutencao com halotano. A avaliacao cardiorrespiratoria foi realizada pela mensuracao dos parâmetros de frequencias cardiaca e respiratoria, pressao arterial media invasiva, equilibrio acido-base por hemogasometria arterial e perfil hematologico de hematocrito, proteina plasmatica total e glicemia. Foram mensurados os tempos de inducao ao decubito em segundos e o tempo de recuperacao a estacao em minutos. A tecnica anestesica demonstrou que apos a administracao de romifidina, houve facilidade de manipulacao no periodo pre-anestesico e que a inducao com tiletamina/zolazepam e suave e destituida de excitacao ou movimentos involuntarios, promovendo uma adequada transicao para a anestesia inalatoria. A recuperacao a estacao mostrou-se sem intercorrencias. Houve alteracoes significativas nos parâmetros de frequencias cardiaca e respiratoria e pressao arterial media. Os dados obtidos referentes ao equilibrio acido-base e perfil hematologico de hematocrito, proteina plasmatica total e glicemia tambem estiveram significativamente alterados nos tempos estudados. A tecnica anestesica, associada ao decubito lateral, produziu acidose respiratoria com presenca de acidemia. Apos a inducao anestesica houve a ocorrencia de hipoxemia transitoria.