Marília de Albuquerque Bonelli

Evaluation of cranial tibial and extensor carpi radialis reflexes before and after anesthetic block in cats

Objectives This study aimed to test the extensor carpi radialis and cranial tibial reflexes in cats before and after anesthetic block of the brachial and lumbosacral plexus, respectively, to determine whether they depend on a myotatic reflex arc. Methods Fifty-five cats with a normal neurologic examination that were referred for elective gonadectomy were divided into group 1 (29 cats) for testing the extensor carpi radialis reflex, and group 2 (26 cats) for testing the cranial tibial reflex. In group 1, the extensor carpi radialis reflex was tested after anesthetic induction and 15 mins after brachial plexus block with lidocaine. In group 2, the cranial tibial, withdrawal and patellar reflexes were elicited in 52 hindlimbs and retested 15 mins after epidural anesthesia. Results In group 1, before the anesthetic block, 55.17% of the cats had a decreased and 44.83% had a normal extensor carpi radialis reflex. After the block, 68.96% showed a decreased and 27.59% a normal reflex. No cat had an increased or absent reflex before anesthetic block. In group 2, prior to the anesthetic block, 15.38% of the cats had a decreased cranial tibial reflex and 84.62% had a normal response, whereas after the block it was decreased in 26.92% and normal in 73.08% of the cats. None of the cats had an increased or absent reflex. Regarding the presence of both reflexes before and after anesthetic block, there was no significant difference at 1% (P = 0.013). Conclusions and relevance The extensor carpi radialis and cranial tibial reflexes in cats are not strictly myotatic reflexes, as they are independent of the reflex arc, and may be idiomuscular responses. Therefore, they are not reliable for neurologic examination in this species.

Diagnosis and Treatment of Primary Erythrocytosis in a Dog: A Case Report.

Primary erythrocytosis, or polycythemia vera, is a myeloproliferative disease caused by the exaggerated increase of erythroid precursor cells in the bone marrow. We report the case of an 11-year-old male mixed-breed dog that had tachypnea and spastic tetraplegia. There was a significant increase in hematocrit. After phlebotomy and fluid therapy, the dogs condition improved. A diagnosis of primary erythrocytosis was supported by serum levels of erythropoietin. The dog responded well to treatment with administration of hydroxyurea (15 mg/kg), phlebotomies, and fluid therapy. However, after 18 months, he had an acute recurrence of clinical signs and was euthanized. We observed that long-term maintenance with hydroxyurea at a dosage of 15 mg/kg every 48 hours was adequate for managing polycythemia vera, with a survival time of 18 months in the present case. However, longer dose intervals are likely not appropriate. We believe that this may be helpful to other veterinarians facing the same problems in the treatment of polycythemia vera.

Anestesia epidural na cirurgia descompressiva lombossacral de cães

The objective of this study was to evaluate the feasibility, effectiveness, advantages and disadvantages of lumbosacral epidural anesthesia with inhalational anesthesia in surgical decompression of the cauda equina, since this surgery has a lengthy and painful recovery from anesthesia. For this, 11 adult dogs which showed clinical signs of cauda equina syndrome were used. After the epidural, anesthesia in six of 11 patients, spinal tap in L7-S1, with bupivacaine 0.5% anesthetic was used. Physiological parameters (heart, vascular, respiratory and body temperature) were measured before, 10 minutes after, and 30 minutes after the epidural, after the laminectomia and 60 minutes and 90 minutes after the epidural, both in the epidural group and the control group. Animals that had ep showed a significant reduction in consumption of inhaled anesthetic and time of extubation. There were no neurological deficits caused by epidural anesthesia compared with the group without epidural anesthesia. It was concluded that the epidural anesthesia technique is effective in lumbosacral decompression surgeries, leading to a lower risk for the anesthetized animal.

Substituição da agulha isolada para eletroneuroestimulação pela agulha metálica de cateter intravenoso, na verificação da punção epidural, em cães

The electric neurostimulator was used as an adequate mean for the confirmation of the correct placement of the tip of the insulated needles in the lumbosacral epidural space through small electric stimulations causing muscle contractions by using an intravenous catheter needle instead of an electric neurostimulation insulated needle. Forty dogs were selected based on the need for an epidural block for orthopedic, abdominal or retroumbilical surgical procedures. Electrical stimuli were applied from 1.5 to 0.5mA during a gradual introduction of the needle into the lumbosacral vertebral canal. Responses that were considered as indicative of the correct placement of the needle and stimulation of the cauda equina were muscle contractions in the pelvic limbs, tail or anus. An association of lidocaine, bupivacaine and tramadol was then administered. Adequate epidural anesthesia was confirmed through relaxation of the anal sphincter, absence of patellar and flexor reflexes and analgesia of the abdominal surgical area. The authors were able to conclude that the method used was effective to confirm the correct needle placement in the epidural space during regional anesthesia in dogs.

Cardiovascular and respiratory alterations in dogs during cervical myelography using ioversol

Subarachnoid infusion of most contrast mediums and the steps involved in performing a cervical myelography have adverse affects that can discourage its use in the radiographic diagnosis of spinal cord diseases. Thus, the cardiovascular and respiratory alterations associated with neck flexion, subarachnoid puncture, and cerebrospinal fluid drainage during subarachnoid infusion of ioversol (320mgI/mL) in dogs under general anesthesia using isoflurane were evaluated. The dogs received subarachnoid infusion of autologous cerebrospinal fluid kept at 38°C - control group (GC); ioversol 0.3mL/kg at 25°C (GI25) and ioversol 0.3mL/kg heated to 38°C (GI38). Each dog had its heart rate (HR), systolic arterial pressure (SAP), diastolic arterial pressure (DAP), respiratory rate (RR), oxyhemoglobin saturation (SaO2) and electrocardiography readings (PR and QT intervals) recorded. Group comparisons showed no statistical difference regarding neck positioning, subarachnoid puncture, and subarachnoid infusion of contrast medium on HR, RR and SaO2, cardiac rhythm or conduction. However, isoflurane significantly increased PR and QT intervals. Based on these findings, it is concluded that the steps involved in cervical myelography and the use of ioversol 320mgI/mL at 0.3mL/kg (25oC and 38oC) during cervical myelography did not result in relevant cardiovascular and respiratory alterations, except for an elevation in arterial pressure after injection of ioversol.

Lesão iatrogênica meningomedular em um cão submetido à espondilectomia ventral para tratamento de extrusão crônica de disco intervertebral cervical

Our objective was to describe the occurrence of an iatrogenic meningo-medullary lesion and the trans-surgical complications in an eight-year-old male Daschund, which presented flacid tetraparesis for two months, and underwent ventral spondylectomy to treat a chronic cervical intervertebral disc extrusion. During the removal of the herniated disc with dental picks and hemostatic forceps, we observed meningeal dislocation with medullary laceration and an immediate reduction in cardiovasculatory and respiratory parameters, which progressed to a cardiorespiratory arrest that was non-responsive to medication and finally led to the death of the patient.