Paravertebral brachial plexus block in sheep: a cadaveric and in vivo study.

The Objective of the present study was to evaluate paravertebral brachial plexus block in sheep. A group of 13 healthy sheep with 20.10 ± 2.20 kg weight and five months of age were used. In phase I, in five sheep, an insulated needle attached to a nerve stimulator was directed to the location of C6, C7, C8 and T1 nerves and a 1.50 mL of a solution containing 1:1 methylene blue 1.00% and lidocaine 1.00% was injected at each site. Then, the cervical and thoracic areas were dissected and assessed in the cadavers. In phase II, cervical paravertebral block with 2.00% lidocaine and subsequent assessments were done in eight live sheep. Cadaveric evaluations revealed dye spread in C6 to T1 nerves: 61.75 ± 5.50, 72.75 ± 9.18, 40.75 ± 2.99 and 18.75 ± 3.30 mm, respectively. In three sheep, dye distribution in the anterior mediastinum was observed. In phase II, the onsets of anesthesia were determined within 10 and 15 min for sensory and motor blocks, respectively. Anesthesia at axillary, musculocutaneous, radial and ulnar skin sites and motor block lasted for 67.50 ± 15.80, 63.70 ± 16.00, 55.00 ± 21.70, 56.70 ± 19.70 and 76.40 ± 24.30 min, respectively. In three sheep, no anesthesia was observed for radial and ulnar skin sites. In conclusion, paravertebral brachial plexus block in sheep provided an acceptable block for the upper parts of the elbow joint, however, it was not effective and reliable for more distal structures.

Comparison of intravenous regional anaesthesia with lidocaine and ropivacaine in dogs.

The present study was designed to compare the effects of lidocaine and ropivacaine in intravenous regional anaesthesia (IVRA) in dogs. Twelve adult male dogs were used. Under isoflurane anaesthesia, exsanguination was performed in the target forelimb. Then, a blood pressure cuff was encircled around the limb proximal to the elbow joint with a pressure of approximately 150 mmHg above the mean arterial blood pressure. The animals then received one of the two treatments of lidocaine (3 mg/kg) or ropivacaine (1.5 mg/kg) with a final volume of 0.6 mL/kg into the cephalic vein. After 60 min, the anaesthesia was disrupted and the tourniquet was removed using intermittent opening (30 s) and closing (5 min) manner for three times. The results revealed that at 20 and 30 min after the initiation of IVRA, the dogs in ROP showed higher analgesia than LID. A leakage under the tourniquet during IVRA was detected. Tremor and hypersalivation were observed after tourniquet removal in some dogs. It was concluded that ropivacaine might provide a higher quality of anaesthesia than lidocaine in IVRA in dogs. The development of local anaesthetic toxicity is a major concern and should be considered at the time of tourniquet removal.

Evaluation of the effect of lidocaine epidural injection on immunological indices in dogs under total intravenous anesthesia submitted to ovariohysterectomy.

This study aimed to evaluate the effects of epidural anaesthesia with lidocaine in combination with general anaesthesia with propofol on some immunologic indices in dogs undergoing ovariohysterectomy. Twelve adult dogs were anesthetized with propofol (induction: 7 mg/kg; maintenance: 0.4 mg/kg/min) and were then allocated into either groups of epidural saline (control) or epidural lidocaine (4 mg/kg; treatment). All the included animals underwent ovariohysterectomy operation. The immune responses, hematologic parameters and cortisol levels were assessed in the predetermined intervals. Evaluation of the innate immunity revealed higher significant levels in the bactericidal, lysozyme and myeloperoxidase activities at 4 hours after surgery in the treatment. In the humoral immunity, the total immunoglobulin level was significantly higher in the treatment. In the assessment of cellular immunity, higher significant values were detected in the delayed skin sensitivity to phytohemagglutinine injection after 48 and 72 hours in the treatment. Moreover, higher significant levels were observed in the number and percentage of lymphocytes as well as an increase in the percentage of monocytes in the treatment at 4 hours after the operation. Notably, the cortisol hormone in the treatment was lower than control at 4 hours of the surgery. In conclusion, epidural anaesthesia with lidocaine when added to general anaesthesia with propofol attenuated the suppression of the innate and cellular immune responses produced by anaesthesia and surgery in the dogs.

The Effects of Propofol Anesthesia on Lipid Profile and Some Biochemical Indices in Cats.

The aim of the present study was to evaluate lipid profile (triglyceride, total cholesterol, HDL, LDL, and VLDL), pancreas (lipase and amylase), liver (AST, ALT, and ALP), blood urea nitrogen, creatinine, uric acid, sodium and potassium function indicators in cats undergoing two different durations of anesthesia with propofol. Ten adult female cats were randomly divided into two groups (n= 5) and anaesthetized with propofol 1% (induction: 8 mg/kg; infusion: 0.3 mg/kg/min) for either 45 or 90 minutes. Blood samples were collected at predetermined intervals up to 72 hours later. Comparison of the measured variables between treatments did not show significant differences. Triglyceride and cholesterol levels showed significant increase after induction of anesthesia (P < .05). The highest triglyceride and cholesterol values were recorded at 6 and 24 hours. HDL was lower while LDL and VLDL were higher at several time points after anesthesia (P < .05). Higher values of lipase, ALT and AST were detected after induction (P < .05). All the observed alterations were within normal ranges. In conclusion, propofol anesthesia was associated with some changes in lipid profile, as well as pancreatic and liver function indices, which should be considered in clinical situations. It seems that in the absence of pre- or co-existing disturbances, induction and maintenance of anesthesia with propofol did not carry additional risk to cats.

Effect of phentolamine mesylate on regression of lidocaine-epinephrine epidural anaesthesia in sheep.

OBJECTIVE: To determine the impact of epidural phentolamine on the duration of anaesthesia following epidural injection of lidocaine-epinephrine. STUDY DESIGN: Blinded randomized experimental study. ANIMALS: A group of 12 adult ewes weighing 25.7 ± 2.3 kg and aged 8-9 months. METHODS: All sheep were administered epidural lidocaine (approximately 4 mg kg-1) and epinephrine (5 µg mL-1). Of these, six sheep were randomized into three epidural treatments, separated by 1 week, administered 30 minutes after lidocaine-epinephrine: SAL: normal saline, PHE1: phentolamine (1 mg) and PHE2: phentolamine (2 mg). The other six sheep were administered only epidural lidocaine-epinephrine: treatment LIDEP. Each injection was corrected to 5 mL using 0.9% saline. Noxious stimuli were pinpricks with a hypodermic needle and skin pinch with haemostatic forceps to determine the onset and duration of sensory and motor block. Heart rate, noninvasive mean arterial pressure (MAP), respiratory rate and rectal temperature were recorded. RESULTS: The onset times were not different among treatments. Duration of sensory block was significantly shorter in SAL (57.5 ± 6.2 minutes), PHE1 (60.7 ± 9.0 minutes) and PHE2 (62.0 ± 6.7 minutes) than in LIDEP (81.7 ± 13.4 minutes) (p < 0.05). Duration of motor blockade was significantly shorter in PHE1 (59.4 ± 5.4 minutes) and PHE2 (54.3 ± 4.0 minutes) than in SAL (84.8 ± 7.0 minutes) and LIDEP (91.5 ± 18.2 minutes) (p < 0.01). MAP in PHE2 was decreased at 10 minutes after administration of phentolamine (p < 0.05). CONCLUSION AND CLINICAL RELEVANCE: Epidural administration of 5 mL normal saline after epidural injection of lidocaine-epinephrine reduced the duration of sensory but not motor block in sheep. Epidural administration of phentolamine diluted to the final volume of 5 mL diminished both the duration of sensory and motor block in sheep administered epidural lidocaine-epinephrine.

Management of a bilateral mandibular fracture in a single-humped camel.

In the present case report, the comprehensive management of a bilateral mandibular fracture in a single-humped camel including pre-, peri- and post-operative cares is described. A one-year-old camel with the overhanging of the rostral part of the lower jaw which occurred seven days ago was presented. After clinical and radiographic examinations, a bilateral mandibular fracture at the caudal part of canine teeth was diagnosed. It was decided to repair the fracture surgically under general anesthesia. The camel was restrained in sitting position and was remained in this position during anesthesia and surgery period. After premedication with acepromazine (0.10 mg kg-1) and xylazine (0.20 mg kg-1) intramuscularly, anesthesia was induced using ketamine and diazepam intravenously (2.00 and 0.10 mg kg-1, respectively). Maintenance of anesthesia was performed by repeated doses of xylazine and ketamine intravenously (0.10 and 1.00 mg kg-1, respectively) as needed. After preparation of the oral cavity, the fracture was reduced and an interfragmentary wire and an interdental wire (1.00 mm diameter size) were applied on each side of the mandible for the fixation of fracture segments. After two months, the interdental wires were removed while the interfragmentary wires were left intact. Follow up the camel three months after surgery, showed the full ability of prehension and chewing of roughages by the camel.