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.

Evaluation of intraperitoneal and incisional bupivacaine or levobupivacaine for postoperative analgesia in ovariohysterectomized dogs

Background: Ovariohysterectomy (OHE) is the most commonly performed elective surgical procedure in companionanimals. OHE offers benefits of control of population and decreased risk of potentially life-threatening diseases such asmammarian tumours and pyometra. Traditional OHE intervention causes inflammation and pain due to trauma duringorgan manipulation. The purpose of this study was to compare the effect of intraperitoneal and incisional administrationof bupivacaine (BP) or levobupivacaine (LP) on postoperative analgesia in dogs undergoing the OHE procedure.Materials, Methods & Results: A total of 24 mix-breed bitches aged between 1 - 3 years and weighed 19 - 20 kg wereused in this study. The animals were divided into three groups as control (n = 8), BP (n = 8) and LP group (n = 8). Theanimals were kept under surveillance at the hospitalisation unit of the animal hospital for one day before the elective OHE.The dogs were fasted for 12 h before the surgery, with adlib water consumption. Atropine sulphate 0.045 mg/kg was administered subcutaneously approximately 30 min before general anaesthesia. Midazolam (0.3 mg/kg) was intravenouslyinjected into all dogs for pre-anaesthetic medication. After sedation, anaesthesia was induced with propofol (4 mg/kg, IV)and then the dogs were orotracheally intubated using cuffed endotracheal tubes. General anaesthesia was maintained byadministration of 2% isoflurane. The ventral abdomen was prepared aseptically for OHE following the general anaesthesia.All animals were operated on by the same surgeon. During surgery, sprayed bupivacaine 0.5% (4.4 mg/kg) with an equalvolume of saline in BP group, levobupivacaine 0.5% (4.4 mg/kg) with an equal volume of saline in LP were then appliedover the ovaries, uterine broad ligaments and cervix uteri. After removal of the uterine body, either LP or BP was sprayedto left and right, or cranial and caudal parts of the abdominal cavity...

Evaluation of intraperitoneal and incisional bupivacaine or levobupivacaine for postoperative analgesia in ovariohysterectomized dogs

Background: Ovariohysterectomy (OHE) is the most commonly performed elective surgical procedure in companionanimals. OHE offers benefits of control of population and decreased risk of potentially life-threatening diseases such asmammarian tumours and pyometra. Traditional OHE intervention causes inflammation and pain due to trauma duringorgan manipulation. The purpose of this study was to compare the effect of intraperitoneal and incisional administrationof bupivacaine (BP) or levobupivacaine (LP) on postoperative analgesia in dogs undergoing the OHE procedure.Materials, Methods & Results: A total of 24 mix-breed bitches aged between 1 - 3 years and weighed 19 - 20 kg wereused in this study. The animals were divided into three groups as control (n = 8), BP (n = 8) and LP group (n = 8). Theanimals were kept under surveillance at the hospitalisation unit of the animal hospital for one day before the elective OHE.The dogs were fasted for 12 h before the surgery, with adlib water consumption. Atropine sulphate 0.045 mg/kg was administered subcutaneously approximately 30 min before general anaesthesia. Midazolam (0.3 mg/kg) was intravenouslyinjected into all dogs for pre-anaesthetic medication. After sedation, anaesthesia was induced with propofol (4 mg/kg, IV)and then the dogs were orotracheally intubated using cuffed endotracheal tubes. General anaesthesia was maintained byadministration of 2% isoflurane. The ventral abdomen was prepared aseptically for OHE following the general anaesthesia.All animals were operated on by the same surgeon. During surgery, sprayed bupivacaine 0.5% (4.4 mg/kg) with an equalvolume of saline in BP group, levobupivacaine 0.5% (4.4 mg/kg) with an equal volume of saline in LP were then appliedover the ovaries, uterine broad ligaments and cervix uteri. After removal of the uterine body, either LP or BP was sprayedto left and right, or cranial and caudal parts of the abdominal cavity...(AU)

Repercussões oculares do bloqueio retrobulbar com diferentes anestésicos locais em cães normais / Ocular effects of retrobulbar block with different local anesthetics in healthy dogs

O objetivo deste estudo foi avaliar os efeitos oculares, a exequibilidade e qualidade do bloqueio retrobulbar pela técnica inferior temporal, em cães, com diferentes anestésicos locais empregando-se agulha epidural de Tuohy. Oito cães foram incluídos no experimento e cada um foi estudado quatro vezes, com intervalo de 15 dias entre os tratamentos: Lido - lidocaína a 2%; Ropi - ropivacaína a 0,5%, Bupi - bupivacaína racêmica a 0,5% e Levo - levobupivacaína a 0,75%. Com exceção da ropivacaína, todos os anestésicos continham epinefrina 1:200.000. Os bloqueios foram realizados nos olhos direitos dos animais imediatamente após a indução anestésica, e os olhos esquerdos, não bloqueados, foram utilizados como controle. Avaliou-se a pressão intraocular, a produção lacrimal e a sensibilidade corneal antes de qualquer procedimento (T0), 30 min após a medicação pré-anestésica (TMPA), 30 min após a indução anestésica (T30), após a recuperação da anestesia (TREC), a cada 60 min até 360 min e 12 e 24 h após o bloqueio. O diâmetro pupilar foi avaliado nos mesmos momentos, exceto no T0. A máxima dilatação pupilar foi observada no grupo Lido seguida pelos grupos Ropi, Bupi e Levo. Todos os anestésicos mantiveram a pressão ocular dentro dos níveis normais para cães e reduziram significativamente a produção lacrimal. A produção lacrimal retornou ao normal primeiramente no grupo Lido, seguida pelo...(AU)

The objective of this study was to evaluate the ocular effects, the feasibility and the quality of retrobulbar block using the inferior temporal technique with different local anesthetics applied with the Tuohy epidural needle in dogs. Eight dogs were included in the experiment and each one was studied four times, with interval of 15 days between the treatments: Lido - 2% lidocaine, Ropi - 0.75% ropivacaine, Bupi - 0.5% racemic bupivacaine and Levo - 0.75% levobupivacaine. Except for the ropivacaine, all of the local anesthetics contained epinephrine at 1:200.000. The blocks were performed in the right eyes immediately after anesthetic induction, and the left eyes were not blocked and were used as controls. The intraocular pressure, tear production and corneal sensitivity were evaluated before any procedure (T0), 30 min after premedication (TMPA), 30 min after anesthetic induction (T30), after recovery from anesthesia (TREC), every 60 min up to 360 min and 12 and 24 h after the block. The pupil diameter was evaluated at the same time points, excepted at T0. The maximum pupillary dilatation was observed in Lido group at T120 followed by Ropi at TREC, and Bupi and Levo at T30. All of the anesthetics maintained eye pressure within acceptable levels for normal dogs and significantly reduced tear production. Tear production returned earliest in group Lido, followed by Bupi, Ropi...(AU)

Comparison of the effects of epidurally administered bupivacaine and levobupivacaine in conscious dogs

Background: The epidural administration of local anaesthetic agents was advocated for use in any surgical procedure caudal to the diaphragm in dogs but was superior for procedures involving the pelvis, hind limbs, and perineal area. The aim of this study was to determine anaesthetic profiles of bupivacaine (BP) and levobupivacaine (LP) in epidural anaesthesia (EA) and to compare their effects on hemodynamics, blood gases, hematological and biochemical parameters in conscious dogs. Materials, Methods & Results: In this study, a total of 20 adult male dogs from different breeds referred to our clinics for castration purposes were used and allocated into two groups; 10 dogs in BP and 10 dogs in LP groups. In this study, each animal received a 0.5% of either BP or LP epidurally, (a fixed total volume of 0.2 mL/kg) followed by 0.3 mL saline solution to flush the dead space in the valve and catheter. Throughout the epidural anaesthesia, heart rate, respiratory rate, systolic and diastolic blood pressure, mean arterial blood pressure, and body temperature were monitored. Similarly, during the study, haematological measurements at 0th, 2nd, 4th, 6th, and 8th h and biochemical measurements at 0th, 2nd, 4th, 6th, 8th and 24th h in blood samples were examined. Simultaneously, blood gases, and Na+ and K+ levels in arterial blood samples were measured at 0th, 30th, 60th, 120th and 240th min. Nocifensive and motor block status were qualitatively assessed at regular intervals: baseline, 5, 10, 15, 30, 45, 60, 75, 90, 105, 120 min and every 30 min thereafter. Duration of the analgesia was 124.9 ± 28.6 min in the BP group and 77.5 ± 16.8 min in the LP group (P < 0.05). Motor block duration was determined as 248.2 ± 44.2 min for the BP group and 185.9 ± 38.08 min for the LP group (P > 0.05). Motor and sensory block time was longer in the BP group than in the LP group, and similarly, BP generated sensory and motor block in a shorter period of time. While complete motor block was not observed in two animals in the LP group, complete motor block was seen in all the animals in the BP group. Motor block level was determined as 2.8 ± 0.4 in the LP group and 3 ± 00 in the BP group. There were no statistically significant differences between the levels of motor block. In both groups, decreased heart rate and arterial blood pressure were seen following EA. This decline was higher in the BP group. After epidural anaesthesia, slight decline in respiratory rate and body temperature were observed in both groups. There were no significant differences between the groups regarding cardiopulmonary data. Within each group, statistically significant changes in respiratory rates, body temperatures and blood pressures with regards to times were observed in both groups (P < 0.05). Discussion: Similar to the data in the literature, the duration of analgesia and motor block were longer with BP than with LP, and both agents showed close initiation analgesia and motor blockade. The reason for longer motor block by BP may be attributed to its higher lipophilic nature and penetration ability to the myeliniated motor fibrils. In present study, arterial blood pressure dropped, and this was higher in the BP group than in the LP group. These drops were attributed to the ability of sympathetic blockade of BP and LP.

Comparison of the effects of epidurally administered bupivacaine and levobupivacaine in conscious dogs / Comparison of the effects of epidurally administered bupivacaine and levobupivacaine in conscious dogs

Background: The epidural administration of local anaesthetic agents was advocated for use in any surgical procedure caudal to the diaphragm in dogs but was superior for procedures involving the pelvis, hind limbs, and perineal area. The aim of this study was to determine anaesthetic profiles of bupivacaine (BP) and levobupivacaine (LP) in epidural anaesthesia (EA) and to compare their effects on hemodynamics, blood gases, hematological and biochemical parameters in conscious dogs. Materials, Methods & Results: In this study, a total of 20 adult male dogs from different breeds referred to our clinics for castration purposes were used and allocated into two groups; 10 dogs in BP and 10 dogs in LP groups. In this study, each animal received a 0.5% of either BP or LP epidurally, (a fixed total volume of 0.2 mL/kg) followed by 0.3 mL saline solution to flush the dead space in the valve and catheter. Throughout the epidural anaesthesia, heart rate, respiratory rate, systolic and diastolic blood pressure, mean arterial blood pressure, and body temperature were monitored. Similarly, during the study, haematological measurements at 0th, 2nd, 4th, 6th, and 8th h and biochemical measurements at 0th, 2nd, 4th, 6th, 8th and 24th h in blood samples were examined. Simultaneously, blood gases, and Na+ and K+ levels in arterial blood samples were measured at 0th, 30th, 60th, 120th and 240th

Background: The epidural administration of local anaesthetic agents was advocated for use in any surgical procedure caudal to the diaphragm in dogs but was superior for procedures involving the pelvis, hind limbs, and perineal area. The aim of this study was to determine anaesthetic profiles of bupivacaine (BP) and levobupivacaine (LP) in epidural anaesthesia (EA) and to compare their effects on hemodynamics, blood gases, hematological and biochemical parameters in conscious dogs. Materials, Methods & Results: In this study, a total of 20 adult male dogs from different breeds referred to our clinics for castration purposes were used and allocated into two groups; 10 dogs in BP and 10 dogs in LP groups. In this study, each animal received a 0.5% of either BP or LP epidurally, (a fixed total volume of 0.2 mL/kg) followed by 0.3 mL saline solution to flush the dead space in the valve and catheter. Throughout the epidural anaesthesia, heart rate, respiratory rate, systolic and diastolic blood pressure, mean arterial blood pressure, and body temperature were monitored. Similarly, during the study, haematological measurements at 0th, 2nd, 4th, 6th, and 8th h and biochemical measurements at 0th, 2nd, 4th, 6th, 8th and 24th h in blood samples were examined. Simultaneously, blood gases, and Na+ and K+ levels in arterial blood samples were measured at 0th, 30th, 60th, 120th and 240th

Comparison of the effects of epidurally administered bupivacaine and levobupivacaine in conscious dogs / Comparison of the effects of epidurally administered bupivacaine and levobupivacaine in conscious dogs

Background: The epidural administration of local anaesthetic agents was advocated for use in any surgical procedure caudal to the diaphragm in dogs but was superior for procedures involving the pelvis, hind limbs, and perineal area. The aim of this study was to determine anaesthetic profiles of bupivacaine (BP) and levobupivacaine (LP) in epidural anaesthesia (EA) and to compare their effects on hemodynamics, blood gases, hematological and biochemical parameters in conscious dogs. Materials, Methods & Results: In this study, a total of 20 adult male dogs from different breeds referred to our clinics for castration purposes were used and allocated into two groups; 10 dogs in BP and 10 dogs in LP groups. In this study, each animal received a 0.5% of either BP or LP epidurally, (a fixed total volume of 0.2 mL/kg) followed by 0.3 mL saline solution to flush the dead space in the valve and catheter. Throughout the epidural anaesthesia, heart rate, respiratory rate, systolic and diastolic blood pressure, mean arterial blood pressure, and body temperature were monitored. Similarly, during the study, haematological measurements at 0th, 2nd, 4th, 6th, and 8th h and biochemical measurements at 0th, 2nd, 4th, 6th, 8th and 24th h in blood samples were examined. Simultaneously, blood gases, and Na+ and K+ levels in arterial blood samples were measured at 0th, 30th, 60th, 120th and 240th

Background: The epidural administration of local anaesthetic agents was advocated for use in any surgical procedure caudal to the diaphragm in dogs but was superior for procedures involving the pelvis, hind limbs, and perineal area. The aim of this study was to determine anaesthetic profiles of bupivacaine (BP) and levobupivacaine (LP) in epidural anaesthesia (EA) and to compare their effects on hemodynamics, blood gases, hematological and biochemical parameters in conscious dogs. Materials, Methods & Results: In this study, a total of 20 adult male dogs from different breeds referred to our clinics for castration purposes were used and allocated into two groups; 10 dogs in BP and 10 dogs in LP groups. In this study, each animal received a 0.5% of either BP or LP epidurally, (a fixed total volume of 0.2 mL/kg) followed by 0.3 mL saline solution to flush the dead space in the valve and catheter. Throughout the epidural anaesthesia, heart rate, respiratory rate, systolic and diastolic blood pressure, mean arterial blood pressure, and body temperature were monitored. Similarly, during the study, haematological measurements at 0th, 2nd, 4th, 6th, and 8th h and biochemical measurements at 0th, 2nd, 4th, 6th, 8th and 24th h in blood samples were examined. Simultaneously, blood gases, and Na+ and K+ levels in arterial blood samples were measured at 0th, 30th, 60th, 120th and 240th

Repercussões oculares do bloqueio retrobulbar com diferentes anestésicos locais em cães normais / Ocular effects of retrobulbar block with different local anesthetics in healthy dogs

O objetivo deste estudo foi avaliar os efeitos oculares, a exequibilidade e qualidade do bloqueio retrobulbar pela técnica inferior temporal, em cães, com diferentes anestésicos locais empregando-se agulha epidural de Tuohy. Oito cães foram incluídos no experimento e cada um foi estudado quatro vezes, com intervalo de 15 dias entre os tratamentos: Lido - lidocaína a 2%; Ropi - ropivacaína a 0,5%, Bupi - bupivacaína racêmica a 0,5% e Levo - levobupivacaína a 0,75%. Com exceção da ropivacaína, todos os anestésicos continham epinefrina 1:200.000. Os bloqueios foram realizados nos olhos direitos dos animais imediatamente após a indução anestésica, e os olhos esquerdos, não bloqueados, foram utilizados como controle. Avaliou-se a pressão intraocular, a produção lacrimal e a sensibilidade corneal antes de qualquer procedimento (T0), 30 min após a medicação pré-anestésica (TMPA), 30 min após a indução anestésica (T30), após a recuperação da anestesia (TREC), a cada 60 min até 360 min e 12 e 24 h após o bloqueio. O diâmetro pupilar foi avaliado nos mesmos momentos, exceto no T0. A máxima dilatação pupilar foi observada no grupo Lido seguida pelos grupos Ropi, Bupi e Levo. Todos os anestésicos mantiveram a pressão ocular dentro dos níveis normais para cães e reduziram significativamente a produção lacrimal. A produção lacrimal retornou ao normal primeiramente no grupo Lido, seguida pelo...

The objective of this study was to evaluate the ocular effects, the feasibility and the quality of retrobulbar block using the inferior temporal technique with different local anesthetics applied with the Tuohy epidural needle in dogs. Eight dogs were included in the experiment and each one was studied four times, with interval of 15 days between the treatments: Lido - 2% lidocaine, Ropi - 0.75% ropivacaine, Bupi - 0.5% racemic bupivacaine and Levo - 0.75% levobupivacaine. Except for the ropivacaine, all of the local anesthetics contained epinephrine at 1:200.000. The blocks were performed in the right eyes immediately after anesthetic induction, and the left eyes were not blocked and were used as controls. The intraocular pressure, tear production and corneal sensitivity were evaluated before any procedure (T0), 30 min after premedication (TMPA), 30 min after anesthetic induction (T30), after recovery from anesthesia (TREC), every 60 min up to 360 min and 12 and 24 h after the block. The pupil diameter was evaluated at the same time points, excepted at T0. The maximum pupillary dilatation was observed in Lido group at T120 followed by Ropi at TREC, and Bupi and Levo at T30. All of the anesthetics maintained eye pressure within acceptable levels for normal dogs and significantly reduced tear production. Tear production returned earliest in group Lido, followed by Bupi, Ropi...