Lumbar paravertebral block in a rabbit (Oryctolagus cuniculus) submitted to pelvic limb amputation: case report / Bloqueio paravertebral lombar em coelho (Oryctolagus cuniculus) submetido à amputação de membro pélvico: relato de caso

The concern about pain management in exotic mammals is increasing. However, only a few studies describe locoregional anesthesia techniques in rabbits. Thus, this report aims to describe the lumbar paravertebral block, guided by peripheral nerve stimulation, in a rabbit undergoing mid-femoral amputation. We received a one-year-old rabbit weighing 1.27kg with a history of non-union of the right femur and osteomyelitis. The animal came to us for high pelvic limb amputation. After premedication with ketamine, midazolam, and morphine, the patient was maintained under general anesthesia in a non-rebreathing circuit under spontaneous ventilation with isoflurane vaporized in 0.6 oxygen. Using a peripheral nerve stimulator, we performed the lumbar paravertebral block, positioning the needle between the L5 and L6 vertebrae and injecting 0.2mL/kg bupivacaine. The patient remained stable throughout the procedure, without the need for analgesic rescue with opioids during surgery and postoperatively. The discharge occurred after 24 hours. The lumbar paravertebral block proved efficient for trans and postoperative analgesia for high pelvic limbic amputation in rabbits.

A preocupação quanto ao manejo da dor em mamíferos exóticos é crescente, entretanto existem poucos estudos que descrevem o uso de técnicas de anestesia locorregional em coelhos. Assim, este relato tem por objetivo descrever o bloqueio paravertebral lombar guiado por neurolocalizador em um coelho submetido à amputação mediofemoral. Um coelho de um ano de idade e 1,27kg foi atendido com histórico de não união de fêmur direito e osteomielite, sendo encaminhado para amputação alta do membro pélvico. Após pré-medicação com cetamina, midazolam e morfina, o paciente foi mantido sob anestesia geral em circuito sem reinalação de gases, sob ventilação espontânea com isoflurano vaporizado em 0,6 de oxigênio. O bloqueio do plexo lombar foi realizado pela abordagem paravertebral, com o auxílio de neurolocalizador, sendo a agulha posicionada entre as vértebras L5 e L6 e injeção de 0,2mL/kg de bupivacaína 0,5%. O paciente manteve-se estável durante todo o procedimento, sem a necessidade de resgate analgésico com opioides no trans e no pós-operatório. O paciente recebeu alta médica após 24 horas. O bloqueio lombar paravertebral demonstrou-se eficiente para analgesia trans e pós-operatória no procedimento de amputação alta de membro pélvico de coelho.

Bloqueios dos nervos ciático e femoral guiado por neuroestimulador em Chinchilla lanigera submetida a osteossíntese de tíbia / Nerve stimulator-guided ciatic and femoral nerve block during tibial osteosynthesis in Chinchilla lanigera

Background: Nociceptive stimulation in orthopedic surgery requires effective pain management to ensure trans andpostoperative patient comfort. Several techniques can be used for this, and multimodal analgesia protocols such as guidedlocoregional blocks provide a balanced effect, as they enable the use of low-dose anesthetics and offer rapid recovery. Thebenefits of specific nerve blocks in domestic animals are well known; however, there are few reports that have ascertainedtheir safety in wild species. This report is aimed at describing the successful use of neurolocalizer-guided sciatic andfemoral nerve blocks during tibial osteosyntheses in a chinchilla.Case: A 9-month-old chinchilla weighing 0.56 kg was referred for surgery for proximal and mid-diaphyseal tibia fracturesresulting from trauma. Following preanesthetic evaluation, the animal received intramuscular dexmedetomidine (15 µgkg1) as preanesthetic medication. Sedation was apparent after 15 min and was verified by a decreased activity, the animalallowing manipulation, absence of the eyelid and righting reflexes, and limb movement after clamping removal of limbafter clamping. After achieving sedation, anesthesia was induced and maintained with sevoflurane (FiO2 = 1.0), suppliedthrough a nasoral mask. Sciatic and femoral nerve blocks were performed with the aid of a neurostimulator. A needle wasinserted into the femoral triangle, cranial to the femoral artery, and into the depression between the sciatic tuberosity andthe greater femoral trochanter. The neurostimulator was set at a pulse frequency of 1 Hz, pulse duration of 0.1 ms andinitial current of 0.6 mA. The needle was advanced toward the nerves until muscle contractions were observed, and thecurrent was gradually reduced until contractions were manifested at a minimum current...

Bloqueios dos nervos ciático e femoral guiado por neuroestimulador em Chinchilla lanigera submetida a osteossíntese de tíbia / Nerve stimulator-guided ciatic and femoral nerve block during tibial osteosynthesis in Chinchilla lanigera

Background: Nociceptive stimulation in orthopedic surgery requires effective pain management to ensure trans andpostoperative patient comfort. Several techniques can be used for this, and multimodal analgesia protocols such as guidedlocoregional blocks provide a balanced effect, as they enable the use of low-dose anesthetics and offer rapid recovery. Thebenefits of specific nerve blocks in domestic animals are well known; however, there are few reports that have ascertainedtheir safety in wild species. This report is aimed at describing the successful use of neurolocalizer-guided sciatic andfemoral nerve blocks during tibial osteosyntheses in a chinchilla.Case: A 9-month-old chinchilla weighing 0.56 kg was referred for surgery for proximal and mid-diaphyseal tibia fracturesresulting from trauma. Following preanesthetic evaluation, the animal received intramuscular dexmedetomidine (15 µgkg1) as preanesthetic medication. Sedation was apparent after 15 min and was verified by a decreased activity, the animalallowing manipulation, absence of the eyelid and righting reflexes, and limb movement after clamping removal of limbafter clamping. After achieving sedation, anesthesia was induced and maintained with sevoflurane (FiO2 = 1.0), suppliedthrough a nasoral mask. Sciatic and femoral nerve blocks were performed with the aid of a neurostimulator. A needle wasinserted into the femoral triangle, cranial to the femoral artery, and into the depression between the sciatic tuberosity andthe greater femoral trochanter. The neurostimulator was set at a pulse frequency of 1 Hz, pulse duration of 0.1 ms andinitial current of 0.6 mA. The needle was advanced toward the nerves until muscle contractions were observed, and thecurrent was gradually reduced until contractions were manifested at a minimum current...(AU)

BLOQUEIO DO NERVO PUDENDO COM AUXÍLIO DE NEUROESTIMULADOR EM BOVINOS

Os exames clínicos da genitália externa dos machos bovinos, por vezes, exigem o bloqueio anestésico local do nervo pudendo para o relaxamento do músculo retrator e consequentemente, exposição da bainha prepucial e do pênis. Sabe-se que existe dificuldade de acesso ao nervo pudendo devido à localização do mesmo, fato que dificulta a execução da técnica de bloqueio e induz imprecisão no volume anestésico aplicado. Os neuroestimuladores têm sido empregados para aumentar a precisão para a localização do nervo reduzindo o volume injetado sem prejudicar a eficácia do anestésico, pois o mesmo é depositado próximo à bainha do nervo. Considerando que existe necessidade de aprimoramento da técnica de bloqueio anestésico para que se realize o exame físico da genitália externa de bovinos, objetivou-se pelo presente estudo empregar o neuroestimulador como método acessório para a realização do bloqueio do nervo pudendo empregando-se a dose de 1 mg/kg de lidocaína em bovinos da raça Gir e Holandesa. Aditivamente, avaliou-se comparativamente a eficácia da lidocaína alcalinizada. Foram utilizados 20 bovinos adultos, distribuídos em quatro grupos experimentais: administração de lidocaína sem vasoconstritor em touros da raça Gir (GL, n=10) ou Holandesa (HL, n=10) e administração de lidocaína sem vasoconstritor alcalinizada com bicarbonato sódico 8,4% em touros da raça Gir (GLA, n=10) ou Holandesa (HLA, n=10) no bloqueio anestésico local do nervo pudendo. Foram empregados os mesmos animais, respeitando-se um intervalo mínimo de 15 dias entre cada tratamento. O ponto de aplicação para bloqueio do nervo pudendo foi localizado por meio de agulha introduzida na região isquiática (direita e esquerda). Essa agulha possuía conexão, por meio de fio, com equipamento de neuroestimulador elétrico, que quando acionado produzia passagem de corrente elétrica, junto à bainha do nervo pudendo que produzia contração do óstio prepucial e ânus. Na sequência aplicou-se lidocaína ou lidocaína alcalinizada pela adição de bicarbonato sódico 8,4%, na dose de 1mg/kg, em ambas as raças. Por um período de quatro horas após os bloqueios, foi investigado se ocorria exposição manual ou espontânea e o comprimento da exposição e a sensibilidade peniana, bem como os sinais de incoordenação motora. O efeito anestésico foi comprovado pela facilidade de relaxamento peniano, por meio da tração manual. O início do relaxamento seguido da exposição peniana manual ocorreu em 100% dos animais após 20 (HL e HLA) a 30 (GL e GLA) minutos da injeção do anestésico. A exposição peniana, por 90 minutos, ocorreu em 100% dos bovinos, independente do grupo e atingiu 220 minutos no grupo HLA. O uso do neuroestimulador contribuiu para a eficácia de 100% de bloqueio do nervo pudendo. A neuroestimulação aumentou a precisão da localização do nervo pudendo e favoreceu à padronização da dose de 1 mg/kg de lidocaína regular, sem que se observasse aumento da eficácia com o uso da lidocaína alcalinizada.

The bulls sometimes require local anesthetic pudendal nerve block (PNB) to exposure its prepuce sheath and the penis. The pudendal nerve has deep location, that makes difficult the execution of the anesthetic block and could causes technique inaccuracy. The nerve stimulator helps to reduces injected anesthetic volume and increases the efficacy of the nerve block since improves the accuracy of the anesthetic injection at the nerve sheath however have been not yet employed to help of the bovines pudendal nerve block. The PNB is mandatory to perform the physical examination of the external genitalia of bulls and the nerve stimulator can help the bovines pudendal nerve localization. The efficacy of regular and alkalinized lidocaine (1mg/kg) in the PNB was compared in ten Gir and ten Holstein bulls allocated in four groups: Gir (GL) or Holstein (HL) injected with lidocaine without vasoconstrictor and Gir (GLA) or Holstein (HLA) injected with lidocaine alkalinized with sodium bicarbonate 8,4%. There was two weeks interval to re-test the PNB for each group. The pudendal nerve was search by inserting a special needle in the right and left ischial region. By a wire connected at the hub of the special needle the triggered electric current until find the point nearby the sheath of the pudendal nerve. The ideal localization of the needle tip was confirmed by the contraction of the preputial ostium and anal sphincter. During four hours after the anesthetic blocks manual or spontaneous penile exposure, length of penile exposure, penile sensitivity and motor incoordination were investigated. The pudendal nerve block exposed the penis easily through traction in all animals. The onset of relaxation followed by manual penile exposure occurred in 100% of the animals after 20 (HL and HLA) at 30 (GL and GLA) minutes of the anesthetic injection. The penile exposure for 90 minutes occurred in 100% of the cattle, independent of the group and reached 220 minutes in the HLA group. The use of the neurostimulator contributed to the efficacy of 100% pudendal nerve block. Neurostimulation increased the accuracy of pudendal nerve localization and favored the standardization of the 1 mg / kg dose of regular lidocaine without increasing the efficacy of alkaline lidocaine.