Intra-articular administration of lidocaine plus adrenaline in dogs: Pharmacokinetic profile and evaluation of toxicity in vivo and in vitro.

The aim of this study was to evaluate the safety of intra-articular (IA) lidocaine plus adrenaline for improving peri-operative analgesia in anaesthetized dogs undergoing arthroscopy of the elbow. A solution of lidocaine (L) 1.98% plus adrenaline 1:100.000 was administered via the IA route and its safety evaluated in terms of cardio-, neuro-, and chondro-toxicity. No bradycardia or hypotension was recorded from induction to the last observational time point. Signs of toxicity of the nervous system could have been masked by the general anaesthesia but lidocaine concentrations detected in the blood were lower than those thought to be capable of producing toxicity. The assessment of in vitro chondrotoxicity showed a dose- and time-dependent effect of lidocaine on the viability of articular cells. Adrenaline appeared to reduce the chondrotoxicity of 1% lidocaine, following an exposure of up to 30 min.

Comparison of ketamine-dexmedetomidine-methadone and tiletamine-zolazepam-methadone combinations for short-term anaesthesia in domestic pigs.

Cardiorespiratory effects, quality of induction, depth of anaesthesia and quality of recovery were compared in pigs anaesthetised with 8 mg/kg ketamine, 20 µg/kg dexmedetomidine and 0.2 mg/kg methadone (KDM, n = 18) or 8 mg/kg tiletamine-zolazepam and 0.2 mg/kg methadone (TZM, n = 9). Anaesthesia with KDM was partially reversed in nine animals with 0.2 mg/kg atipamezole (KDMat). Sedation was observed earlier in the TZM group (47.2 ± 25.3 s) than the KDM group (91.5 ± 37.4 s). Sternal and lateral recumbency were achieved earlier in the TZM group (76.3 ± 36.5 s and 132.1 ± 30.5 s, respectively) than in the KDM group (149.1 ± 58.7 s and 249.2 ± 84.0 s, respectively). PaO2, SaO2 and PaO2:FiO2 were lower in the TZM group (68.7 ± 4.1 mmHg, 93.4 ± 1.4% and 327.2 ± 19.9 mmHg, respectively) than in the KDM group (80.4 ± 5.9 mmHg, 95.7 ± 1.0% and 380.4 ± 25.6 mmHg, respectively). Fshunt and P(A-a)O2 were higher in the TZM group (24.0 ± 11.8% and 31.4 ± 3.8 mmHg, respectively) than in the KDM group (13.4 ± 3.2% and 20.7 ± 7.4 mmHg, respectively). Times from drug injection to first head movements, sternal recumbency and standing/walking were significantly shorter in the KDM group (45.1 ± 10.5, 48.4 ± 12.6 and 54.4 ± 17.8 min, respectively) than in the TZM group (57.8 ± 11.4, 93.1 ± 14.2 and 165.7 ± 56.6 min, respectively). The median recovery score was higher in the TZM group than in the KDMnoat and KDMat subgroups. Both drug combinations provided adequate anaesthesia for minor procedures lasting about 30 min, but TZM was associated with a poor recovery and oxygenation.

Intra-articular administration of lidocaine in anaesthetized dogs: pharmacokinetic profile and safety on cardiovascular and nervous systems.

The intra-articular administration of lidocaine is a frequent practice in human orthopaedic surgical procedures, but an eventual absorption of the drug into the bloodstream can lead to toxicity, mainly concerning the central nervous system and the cardiovascular systems. The purpose of this study was to determine the pharmacokinetic profile and the safety, in terms of cardiovascular and CNS toxicity, of lidocaine after intra-articular administration to anesthetized dogs undergoing arthroscopy. Lidocaine 2% was administered to eight dogs before surgery in differing amounts, depending on the volume of the joints involved, and blood samples were taken at predetermined time points. The maximum serum concentration of lidocaine ranged from 0.50 to 3.01 µg/mL (mean ± SD: 2.18 ± 0.91 µg/mL), and the time to reach it was 28.75 ± 15.74 min. No signs of cardiac toxicity were detected during the entire procedure, and possible signs of CNS toxicity were masked by the anaesthesia. However, concentrations reported in literature as responsible for neurotoxicity in dog were achieved in three of eight investigated subjects. Pending further studies, veterinarians should consider the possibility of side effects occurring following the intra-articular administration of local anaesthetics.

Immobilization of captive tigers (Panthera tigris) with a combination of tiletamine, zolazepam, and detomidine.

The aims of this study were to evaluate the effects of the administration of a combination of tiletamine-zolazepam and detomidine (TZD) in 9 tigers (Panthera tigris). Nine captive tigers were immobilized with tiletamine-zolazepam and detomidine administered intramuscularly. At the end of the procedure immobilization was partially reversed with atipamezole. Lateral recumbency was achieved in 15.6 ± 5.9 min. The median induction score [scored 1 (excellent) to 4 (poor)] was 1. The immobilization score [scored 1 (poor) to 6 (too deep)] was 5 (4-5) at all study times. After atipamezole administration, all tigers experienced severe ataxia and incoordination. Median recovery score [scored 1 (excellent) to 4 (poor)] was 2.5 (range 2-3). No neurologic and/or important adverse reactions were noticed within 5 days after recovery. The combination tiletamine-zolazepam with detomidine proved to be effective in immobilizing captive healthy tigers but it maybe associated with hypertension and ataxia during recovery. Zoo Biol. 34:40-45, 2015. © 2014 Wiley Periodicals Inc.

Ketamine as a part of anaesthetic management in a dog with twiddler's syndrome.

An 11-year-old male German shepherd dog was referred for possible pacemaker implantation. A routine 6-lead electrocardiogram revealed a third-degree atrio-ventricular block with a heart rate of 40 to 45 beats/minute. A transvenous pacemaker implantation procedure was scheduled. The dog was premedicated with 10 µg/kg acepromazine and 5 mg/kg pethidine. A dose of 5 mg/kg ketamine and 0·2 mg/kg diazepam were used for induction and isoflurane in O2 and a constant rate infusion of ketamine (20 to 30 µg/kg/minute) were administered for maintenance of general anaesthesia. Due to a twiddler's syndrome, the pacemaker had to be repositioned. For the second procedure, the same protocol was employed except for a lower dose of ketamine both for induction (3 mg/kg) and constant rate infusion (10 to 15 µg/kg/minute). Ketamine appeared to be useful for both management of anaesthesia and cardiac pacemaker implantation in the absence of a temporary pacemaker.

Comparison of intra-operative analgesia provided by intravenous regional anesthesia or brachial plexus block for pancarpal arthrodesis in dogs.

The aim of this study was to compare intravenous regional anesthesia (IVRA) and brachial plexus block (BPB) for intra-operative analgesia in dogs undergoing pancarpal arthrodesis (PA). Twenty dogs scheduled for PA were intramuscularly sedated with acepromazine (0.03 mg/kg), general anesthesia was intravenously (IV) induced with thiopental (10 mg/kg) and, after intubation, maintained with isoflurane in oxygen. In 10 dogs (GIVRA) IVRA was performed on the injured limb administering 0.6 ml/kg of 0.5% lidocaine. In 10 dogs (GBPB) the BPB was performed at the axillary level with the help of a nerve stimulator and 0.3 ml/kg of a 1:1 solution of 2% lidocaine and 1% ropivacaine was injected. During surgery fentanyl (0.002 mg/kg IV) was administered if there was a 15% increase of HR and/or MAP compared to the values before surgical stimulation. All the standard cardiovascular and respiratory parameters were continuously monitored during surgery. The duration of surgery and the time of extubation were recorded. Data were compared with a 1-way ANOVA test (P<0.05). No patients required fentanyl administration during surgery. All the recorded parameters were similar in the two groups. The two techniques were similar in providing intra-operative analgesia in dogs undergoing orthopaedic surgery.

Alveolar recruiting maneuver in dogs under general anesthesia: effects on alveolar ventilation, gas exchange, and respiratory mechanics.

The aim of this study was to evaluate the effects of a recruiting maneuver (RM) on lung aeration, gas exchange, and respiratory mechanics during general anesthesia in mechanically ventilated dogs. A thoracic computed tomography (CT) scan, an arterial blood sample, and measurement of respiratory mechanics were performed 10 min before (baseline) and both 5 and 30 min after a vital capacity RM in 10 dogs under general anesthesia. The RM was performed by inflating the lung at 40 cm H(2)O for 20 s. Lung aeration was estimated by analyzing the radiographic attenuation of the CT images. Lung aeration and gas exchange improved significantly 5 min after the RM compared to baseline and returned to values similar to baseline by 30 min. Static lung compliance was not significantly affected by the RM. An RM induces a temporary improvement in lung function in healthy dogs under general anesthesia.

Effects of culture, sex, and age on the distribution of handedness: an evaluation of the sensitivity of three measures of handedness.

The present study examined the effects of culture, age, and sex on three measures of handedness: writing hand, Annett's primary handedness items, and a measure based on hand preference for 11 activities. Using data from a large international study, the relationship between the culture in which participants learned to write (as defined by Hofstede's cultural dimensions) and adult handedness was examined. Participants who learned to write in formal cultures were less likely to be classified as left-handed than those who learned in less formal cultures. Older participants and those who learned to write in formal cultures were more likely to be classified as left-handed by the Annett and 11 item measures than by the writing hand classification. Across measures females were less likely to be classified as left-handed than males. Handedness for writing was found to be more sensitive to cultural influences than the other measures. These results suggest that some measures of handedness may be more sensitive to specific handedness aetiologies than others.