Management of urethral obstruction in a cat with epidural sacrococcygeal anesthesia guided by electrical neurostimulation

Background: The treatment for urethral obstruction in cats consists of catheterization, and for this, the cat must be sedated or anesthetized. Sacococcygeal epidural block has the advantage of being close to receptors related to nociception located in the spinal cord and it is safer because it represents lower risk of spinal cord injury or inadvertent application in the subarachnoid space, when compared to the lumbosacral epidural. Nerve stimulation through the neurolocator to identify the epidural space increases the accuracy of this technique. Thus, the objective is to report a case of epidural anesthesia with a sacrococcygeal approach guided by neurostimulation in a cat with urethral obstruction. Case: A 4-year-old male Siamese cat, weighing 4 kg, was referred to the veterinary care with a history of apathy and anorexia for 2 days. From the physical exam, the clinical diagnosis of urethral obstruction was made, and to desobstruction, we chose to perform sacrococcygeal epidural block. Initially, the patient was anesthetized with propofol (4 mg/kg) and midazolam (0.3 mg/kg). To perform the anesthetic block, the cat was placed in sternal decubitus with the hind limbs extended cranially to perform sacrococcygeal epidural block. The positive pole (cathode) was connected to the skin of the right inguinal region at the caudal aspect of the thigh and the neurostimulator was turned on and adjusted to 0.7 mA of stimulating current intensity, 0.1 ms duration and 1 Hz frequency. The needle for electrical neurolocation was introduced in the dorsal midline, perpendicular to the skin surface, between the spinous processes of S3-Cd1 in the skin. The exact injection point was obtained observed by the muscular response of the middle and distal third of the animal's tail with the neurostimulator adjusted to 0.3 mA of intensity, in the same duration and frequency as before. The total volume of 0.9 mL (0.22 mL/kg) of solution containing the combination of 0.6 mL of 0.75% levobupivacaine and 0.3 mL of 2% lidocaine was injected. The success of the block was confirmed by the loss of reflexes of the pelvic limbs and anal sphincter 10 min after the administration of the anesthetic solution. Discussion: In this case, the use of the neurolocator helped to perform an effective sacrococcygeal block, allowing urethral catheterization without the addition of other analgesic agents. This technique desensitizes and relaxes muscles in the regions of the perineum, anus, distal colon and penis, being useful for performing urethral catheterization. The use of smaller anaesthetic volumes to perform sacrococcygeal block makes it possible to achieve a more localized anesthesia, without affecting the motor function of the pelvic limbs. However, in our report, using a combination of levobupivacaine and lidocaine, the pelvic limb block was also verified despite the low volume applied. A hypothesis that could justify the different responses in relation to the pelvic limb block compared to other studies would be due to the different physicalchemical properties of the drugs used. Lidocaine is known to be less fat-soluble than bupivacaine, so it tends to spread more through the epidural space, in order to result in more extensive blocks. The use of a neurostimulator using a fixed electric current of 0.7 mA, pulse 0.1 ms and a frequency of 1 Hz allowed the correct identification of the needle position for the application of the anesthetic.

Hypersensitivity in chicken (Gallus gallus domesticus) due to the association of lidocaine and bupivacaine in neural-guided femoral and sciatic nerve block

Background: Osteosyntheses, orthopedic surgeries that cause highly painful stimulation, are increasingly common inveterinary medicine. Epidural anesthesia is used to provide intraoperative and postoperative analgesia in mammals undergoing pelvic limb surgery. In birds, the synsacrum, the bone originating from the fusion of the lumbar and sacral vertebrae,makes this route inapplicable, thus peripheral nerve block is an easier option in this species. This report describes a caseof local hypersensitivity following the association of lidocaine and bupivacaine in anesthetic blocks of the femoral andsciatic nerves in chickens (Gallus gallus domesticus).Case: A study was conducted in chickens evaluating the effectiveness of anesthetic sciatic and femoral nerve blocks, guidedby a neural stimulator. Thirty-two 42-day-old male chickens of the species Gallus gallus domesticus, double breasted,weighing 1.86 ± 0.5 kg, were randomly divided into four groups: control (CG), lidocaine (LG), bupivacaine (BC) andthe association of lidocaine and bupivacaine (LBG). The doses used were 4 mg/kg of 2% lidocaine and 2 mg/kg of 0.5%bupivacaine, without vasoconstrictor. For CG, 0.9% NaCl solution was used, respecting the total volume of 1 mL/kg.Only one bird from the LBG showed side effects, presenting sensory and motor loss for 24 h after the administration ofthese drugs, before euthanasia was performed using anesthetic induction with isoflurane through a face mask, followedby the intravenous administration of propofol and then potassium chloride. The chicken was submitted to a necropsy andmacroscopically, soft, irregular, brownish lesions with a grayish focus were observed...

Hypersensitivity in chicken (Gallus gallus domesticus) due to the association of lidocaine and bupivacaine in neural-guided femoral and sciatic nerve block

Background: Osteosyntheses, orthopedic surgeries that cause highly painful stimulation, are increasingly common inveterinary medicine. Epidural anesthesia is used to provide intraoperative and postoperative analgesia in mammals undergoing pelvic limb surgery. In birds, the synsacrum, the bone originating from the fusion of the lumbar and sacral vertebrae,makes this route inapplicable, thus peripheral nerve block is an easier option in this species. This report describes a caseof local hypersensitivity following the association of lidocaine and bupivacaine in anesthetic blocks of the femoral andsciatic nerves in chickens (Gallus gallus domesticus).Case: A study was conducted in chickens evaluating the effectiveness of anesthetic sciatic and femoral nerve blocks, guidedby a neural stimulator. Thirty-two 42-day-old male chickens of the species Gallus gallus domesticus, double breasted,weighing 1.86 ± 0.5 kg, were randomly divided into four groups: control (CG), lidocaine (LG), bupivacaine (BC) andthe association of lidocaine and bupivacaine (LBG). The doses used were 4 mg/kg of 2% lidocaine and 2 mg/kg of 0.5%bupivacaine, without vasoconstrictor. For CG, 0.9% NaCl solution was used, respecting the total volume of 1 mL/kg.Only one bird from the LBG showed side effects, presenting sensory and motor loss for 24 h after the administration ofthese drugs, before euthanasia was performed using anesthetic induction with isoflurane through a face mask, followedby the intravenous administration of propofol and then potassium chloride. The chicken was submitted to a necropsy andmacroscopically, soft, irregular, brownish lesions with a grayish focus were observed...(AU)

Comparison of the effects of maropitant, lidocaine, and dextroketamine administered by the intratesticular route in dogs undergoing elective orchiectomy

Background: Balanced anesthesia achieved with combinations of inhaled and injectable drugs administered systemicallyor in loco-regional anesthetic blocks, is widely used in veterinary medicine. The use of anesthesia and/or local analgesiahas already demonstrated benefits in the performance of elective orchiectomy in different species, there is no literature thatevaluates the use of the maropitant intratesticular route. The present study evaluated the cardiorespiratory variables andanalgesia produced by intratesticular blockade with maropitant, lidocaine, or dextroketamine during the trans-operativeperiod along with the discharge and anesthetic recovery of dogs that underwent elective orchiectomy.Materials, Methods & Results: Used twenty-four dogs from routine elective orchiectomy, considered healthy based onthe results of clinical and hematological tests. The animals were randomly divided into three groups and was applied intratesticularly 2% lidocaine at a dose of 1 mg/kg (GL), 5% dextrocetamina at a dose of 2.5 mg/kg (GC), or 1% maropitantat a dose of 1 mg/kg (GM). Anesthesia induction was performed with propofol (to effect), and stabilization of inhalationalanesthesia was achieved with 1.7 V% of sevoflurane diluted in 100% oxygen administered through a calibrated vaporizerand appropriate anesthetic system based on the animal’s weight, being kept under spontaneous ventilation, After induction, we waited 10 min for stabilization of exhaled anesthetic concentration and then administered one of the treatmentsintratesticularly. After five min from the local block the surgical procedure was started during up to 15 min. Heart rate(HR), respiratory rate (RR), systolic arterial pressure (SAP), diastolic arterial pressure (DAP), mean arterial pressure(MAP), oxygen saturation of hemoglobin (SatO2), end-tidal carbon dioxide partial pressure (EtCO2), end-tidal sevofluraneconcentration...

Comparison of the effects of maropitant, lidocaine, and dextroketamine administered by the intratesticular route in dogs undergoing elective orchiectomy

Background: Balanced anesthesia achieved with combinations of inhaled and injectable drugs administered systemicallyor in loco-regional anesthetic blocks, is widely used in veterinary medicine. The use of anesthesia and/or local analgesiahas already demonstrated benefits in the performance of elective orchiectomy in different species, there is no literature thatevaluates the use of the maropitant intratesticular route. The present study evaluated the cardiorespiratory variables andanalgesia produced by intratesticular blockade with maropitant, lidocaine, or dextroketamine during the trans-operativeperiod along with the discharge and anesthetic recovery of dogs that underwent elective orchiectomy.Materials, Methods & Results: Used twenty-four dogs from routine elective orchiectomy, considered healthy based onthe results of clinical and hematological tests. The animals were randomly divided into three groups and was applied intratesticularly 2% lidocaine at a dose of 1 mg/kg (GL), 5% dextrocetamina at a dose of 2.5 mg/kg (GC), or 1% maropitantat a dose of 1 mg/kg (GM). Anesthesia induction was performed with propofol (to effect), and stabilization of inhalationalanesthesia was achieved with 1.7 V% of sevoflurane diluted in 100% oxygen administered through a calibrated vaporizerand appropriate anesthetic system based on the animals weight, being kept under spontaneous ventilation, After induction, we waited 10 min for stabilization of exhaled anesthetic concentration and then administered one of the treatmentsintratesticularly. After five min from the local block the surgical procedure was started during up to 15 min. Heart rate(HR), respiratory rate (RR), systolic arterial pressure (SAP), diastolic arterial pressure (DAP), mean arterial pressure(MAP), oxygen saturation of hemoglobin (SatO2), end-tidal carbon dioxide partial pressure (EtCO2), end-tidal sevofluraneconcentration...(AU)

Influência da lidocaína ou da dextrocetamina pela via intratesticular na anestesia com sevoflurano em cães submetidos à orquiectomia eletiva / Influence of intratesticular administration of lidocaine or dextroketamine in dogs undergoing elective orchiectomy anesthetized with sevoflurane

Background: Elective orchiectomy is one of the most performed surgeries in the veterinary practice and is considered a moderately painful procedure; thus, the use of balanced anesthesia is a good choice. Local anesthetics have shown to be effective for intratesticular and spermatic cord blocks in several species; however, there have been no reports of the use of dextroketamine with this purpose. The objective of this study was to evaluate cardiovascular and respiratory variables, and analgesia produced by intratesticular block using dextroketamine or lidocaine, as well as to assess post-anesthesia recovery and discharge in dogs subjected to elective orchiectomy under inhalation anesthesia with sevoflurane.Materials, Methods & Results: Sixteen dogs which underwent elective orchiectomy were included in this study. All animals were healthy based on clinical and hematological examinations. The animals were randomly distributed into two groups, in which 2% lidocaine at 1 mg/kg (LG) or 5% dextroketamine at 2.5 mg/kg (KG) were administered by the intratesticular route. In both groups, anesthesia was induced with propofol to effect, and maintained with 1.7 V% sevoflurane diluted in 100% oxygen, administered through a calibrated vaporizer and appropriate anesthetic system based on the animals weight, kept under spontaneous ventilation. After induction, 10 min were given for stabilization of exhaled anesthetic concentration before one of the treatments was administered intratesticularly. Five min after administration of the local block, the surgical procedure was performed, which lasted up to 15 min.[...](AU)

Influência da lidocaína ou da dextrocetamina pela via intratesticular na anestesia com sevoflurano em cães submetidos à orquiectomia eletiva / Influence of intratesticular administration of lidocaine or dextroketamine in dogs undergoing elective orchiectomy anesthetized with sevoflurane

Background: Elective orchiectomy is one of the most performed surgeries in the veterinary practice and is considered a moderately painful procedure; thus, the use of balanced anesthesia is a good choice. Local anesthetics have shown to be effective for intratesticular and spermatic cord blocks in several species; however, there have been no reports of the use of dextroketamine with this purpose. The objective of this study was to evaluate cardiovascular and respiratory variables, and analgesia produced by intratesticular block using dextroketamine or lidocaine, as well as to assess post-anesthesia recovery and discharge in dogs subjected to elective orchiectomy under inhalation anesthesia with sevoflurane.Materials, Methods & Results: Sixteen dogs which underwent elective orchiectomy were included in this study. All animals were healthy based on clinical and hematological examinations. The animals were randomly distributed into two groups, in which 2% lidocaine at 1 mg/kg (LG) or 5% dextroketamine at 2.5 mg/kg (KG) were administered by the intratesticular route. In both groups, anesthesia was induced with propofol to effect, and maintained with 1.7 V% sevoflurane diluted in 100% oxygen, administered through a calibrated vaporizer and appropriate anesthetic system based on the animal’s weight, kept under spontaneous ventilation. After induction, 10 min were given for stabilization of exhaled anesthetic concentration before one of the treatments was administered intratesticularly. Five min after administration of the local block, the surgical procedure was performed, which lasted up to 15 min.[...]

Epidural administration of ropivacaine or ropivacaine and xylazine in cattle / Administração epidural de ropivacaína isolada ou associada à xilazina em bovinos

Epidural protocols are commonly used in cattle, enabling surgical procedures with the animal in standingposition, however, problems such as paresis and recumbency beyond that, blocking/recovery times areimportant factors in protocol choice. The aim of this study was to evaluate time and quality of block and systemic effects of two epidural protocols in cattle. Fourteen crossbred cows with 350 ± 170 kg ofbody weight were allocated in two groups with 7 animals each: ropivacaine (GR) they received epiduralinjection of ropivacaine (0.1 mg.kg-1), and ropivacaine/xylazine (GRX) that received ropivacaine andxylazine (0.075 mg.kg-1and 0.05 mg.kg-1 respectively) in the same route. The following parameters wereevaluated, heart rate (HR), respiratory rate (RR), mean blood pressure (MBP), ruminal movements(RM), rectal temperature (RT), durations of epidural block (DB), quality of block (QB), responseto nociceptive stimulus by clamping perineal region, degree of paresis (DP) and hemogasometricevaluation. They were evaluated until 420 minutes after epidural. HR, pH, RR, PaCO2, Na+, Ca++, HCO3-and Base Excess (BE) did not differ between groups. It was observed a slight decrease for RM, andan increase for PaO2 and RT in GRX comparing with GR. Both protocols were effective producing along lasting sensitive block (6 hours in GR, and 7 hours in GRX). In both groups using nociceptivestimuli, the quality of block was considered good/excellent (66% of animals in GR at M360 and 71% ofanimals in GRX at M420). The animals of GRX showed mild to severe paresis from M15 to M240. Weconcluded that both protocols can be used by epidural route, and ropivacaine associated with xylazineadministered by epidural route presents a longer sensitive block than isolated, but causes paresis as aside effect.

Protocolos epidurais são comumente utilizados em bovinos, possibilitando inclusive a realização de procedimentos cirúrgicos com o animal em posição quadrupedal, no entanto, problemas como paresia e decúbito, além do tempo de bloqueio/recuperação são fatores importantes na escolha do protocolo. O objetivo deste estudo foi avaliar dois protocolos de anestesia epidural em bovinos, quanto ao tempo, qualidade de bloqueio e efeitos clínicos. Foram utilizadas 14 vacas mestiças, com peso médio de 350±170 kg, as quais foram alocadas em dois grupos: ropivacaína (GR, n=7) onde os animais receberam a administração epidural de ropivacaína (0,1 mg.kg-1) e ropivacaína/xilazina (GRX, n=7) que receberam ropivacaína e xilazina (0,075 e 0,05 mg.kg-1, respectivamente) pela mesma via. Avaliou-se: freqüência cardíaca (FC), frequência respiratória (f), pressão arterial média (PAM), movimentos ruminais (MR), temperatura retal (TR), tempo de duração do bloqueio anestésico (TB), qualidade do bloqueio (QB) através da resposta a estímulos nociceptivos pelo clampeamento perineal, grau de paresia (GP) e hemogasometria arterial. Os animais foram avaliados por até 420 minutos após a administração. A FC, f, PAM, pH, PaCO2, Na+, Ca++, HCO3 - e Excesso de Base (EB) não diferiram entre grupos. Foi observada uma leve diminuição nos movimentos ruminais e aumento da PaO2 e TR no GRX comparado ao GR. A duração do bloqueio sensitivo foi de 6 e 7 horas para o GR e GRX, respectivamente. A QBfoi considerada boa/excelente frente à estimulação nociceptiva em 66% e 71% dos animais do GR emM360 e do GRX em M420. Os animais do GRX apresentaram sinais de paresia moderada a grave deM15 até M240. Conclui-se que a ropivacaína associada à xilazina pela via epidural apresenta bloqueiosensitivo mais prolongado do que a ropivacaína isolada, no entanto a associação com a xilazina promovebloqueio motor, com sinais de paresia, devendo ser utilizada com cautela em bovinos.

Epidural administration of ropivacaine or ropivacaine and xylazine in cattle / Administração epidural de ropivacaína isolada ou associada à xilazina em bovinos

Epidural protocols are commonly used in cattle, enabling surgical procedures with the animal in standingposition, however, problems such as paresis and recumbency beyond that, blocking/recovery times areimportant factors in protocol choice. The aim of this study was to evaluate time and quality of block and systemic effects of two epidural protocols in cattle. Fourteen crossbred cows with 350 ± 170 kg ofbody weight were allocated in two groups with 7 animals each: ropivacaine (GR) they received epiduralinjection of ropivacaine (0.1 mg.kg-1), and ropivacaine/xylazine (GRX) that received ropivacaine andxylazine (0.075 mg.kg-1and 0.05 mg.kg-1 respectively) in the same route. The following parameters wereevaluated, heart rate (HR), respiratory rate (RR), mean blood pressure (MBP), ruminal movements(RM), rectal temperature (RT), durations of epidural block (DB), quality of block (QB), responseto nociceptive stimulus by clamping perineal region, degree of paresis (DP) and hemogasometricevaluation. They were evaluated until 420 minutes after epidural. HR, pH, RR, PaCO2, Na+, Ca++, HCO3-and Base Excess (BE) did not differ between groups. It was observed a slight decrease for RM, andan increase for PaO2 and RT in GRX comparing with GR. Both protocols were effective producing along lasting sensitive block (6 hours in GR, and 7 hours in GRX). In both groups using nociceptivestimuli, the quality of block was considered good/excellent (66% of animals in GR at M360 and 71% ofanimals in GRX at M420). The animals of GRX showed mild to severe paresis from M15 to M240. Weconcluded that both protocols can be used by epidural route, and ropivacaine associated with xylazineadministered by epidural route presents a longer sensitive block than isolated, but causes paresis as aside effect.(AU)

Protocolos epidurais são comumente utilizados em bovinos, possibilitando inclusive a realização de procedimentos cirúrgicos com o animal em posição quadrupedal, no entanto, problemas como paresia e decúbito, além do tempo de bloqueio/recuperação são fatores importantes na escolha do protocolo. O objetivo deste estudo foi avaliar dois protocolos de anestesia epidural em bovinos, quanto ao tempo, qualidade de bloqueio e efeitos clínicos. Foram utilizadas 14 vacas mestiças, com peso médio de 350±170 kg, as quais foram alocadas em dois grupos: ropivacaína (GR, n=7) onde os animais receberam a administração epidural de ropivacaína (0,1 mg.kg-1) e ropivacaína/xilazina (GRX, n=7) que receberam ropivacaína e xilazina (0,075 e 0,05 mg.kg-1, respectivamente) pela mesma via. Avaliou-se: freqüência cardíaca (FC), frequência respiratória (f), pressão arterial média (PAM), movimentos ruminais (MR), temperatura retal (TR), tempo de duração do bloqueio anestésico (TB), qualidade do bloqueio (QB) através da resposta a estímulos nociceptivos pelo clampeamento perineal, grau de paresia (GP) e hemogasometria arterial. Os animais foram avaliados por até 420 minutos após a administração. A FC, f, PAM, pH, PaCO2, Na+, Ca++, HCO3 - e Excesso de Base (EB) não diferiram entre grupos. Foi observada uma leve diminuição nos movimentos ruminais e aumento da PaO2 e TR no GRX comparado ao GR. A duração do bloqueio sensitivo foi de 6 e 7 horas para o GR e GRX, respectivamente. A QBfoi considerada boa/excelente frente à estimulação nociceptiva em 66% e 71% dos animais do GR emM360 e do GRX em M420. Os animais do GRX apresentaram sinais de paresia moderada a grave deM15 até M240. Conclui-se que a ropivacaína associada à xilazina pela via epidural apresenta bloqueiosensitivo mais prolongado do que a ropivacaína isolada, no entanto a associação com a xilazina promovebloqueio motor, com sinais de paresia, devendo ser utilizada com cautela em bovinos.(AU)