Clinical review of the pharmacological and anaesthetic effects of alfaxalone in dogs.

This clinical review summarises the pharmacological and anaesthetic properties of alfaxalone in the dog. Available pharmacokinetic-pharmacodynamic data and factors affecting the induction dose have been reported. Furthermore, quality of induction and recovery after alfaxalone administration, the use of alfaxalone for total intravenous anaesthesia, and its effects on the cardio-respiratory system, on laryngeal motion, on intraocular pressure and tear production have been evaluated. Finally, the use of alfaxalone in dogs undergoing caesarean section and the effect of intramuscular alfaxalone administration have been considered.

Development of implantation substrates for the collection of radionuclides of medical interest produced via ISOL technique at INFN-LNL.

Accelerator-based techniques with electromagnetic mass separation are considered among the most innovative and promising strategies to produce non-conventional radionuclides for nuclear medicine. Such approach was successfully used at CERN, where the dedicated MEDICIS facility was built, and at TRIUMF, where the ISAC radioactive beam facility was used to produce unconventional α-emitters. In such framework, the Legnaro National Laboratories of the Italian Institute of Nuclear Physics (INFN-LNL) proposed the ISOLPHARM project (ISOL technique for radioPHARMaceuticals), which will exploit radionuclides producible with the SPES (Selective Production of Exotic Species) ISOL (Isotope Separation On-Line) facility to develop novel radiopharmaceuticals. The ISOL technique utilizes the irradiation with a primary beam of particles/nuclei of a production target where radionuclides are produced. A radioactive ion beam is subsequently extracted from the production target unit, and transported up to an analyzing magnet, where non-isobaric contaminants are filtered out. The so-obtained purified radioactive beam is dumped onto an implantation substrate, referred as collection target. Then, the desired nuclides can be chemically harvested from the collected isobars, and the isotopically pure atom collection can be employed to radiolabel high specific activity radiopharmaceuticals. Metallic deposition targets in the form of coated metal foils were mostly used at TRIUMF and CERN. At ISOLPHARM, a different approach is under investigation which foresees the use of soluble cold-pressed collection targets, possibly facilitating the chemical purification process of the collected radionuclides. In this study, the production and characterization of some of the ISOLPHARM collection targets is presented, in particular, soluble salts (NaCl and NaNO3) and organic materials widely used for pharmaceutical tablets production are considered. All such materials proved to be potentially suitable as collection targets, since solid samples were easily produced and resulted compatible with the vacuum conditions required for the ion implantation process. Furthermore, some of the selected substrates were used for proof-of-concept deposition tests with stable silver, to prove their suitability as ISOLPHARM deposition substrates for silver-111, a promising candidate for radiotherapy. Such tests highlighted possible scenarios useful for the development of new alternative materials, as the use of insoluble organic targets.

Cervical hyperaesthesia in dogs: an epidemiological retrospective study of 185 cases.

OBJECTIVES: To describe the prevalence, clinical findings and predictors of disease in dogs with cervical hyperaesthesia. MATERIALS AND METHODS: Medical records of dogs referred for neurological investigation of cervical hyperaesthesia between 2009 and 2013 were retrospectively reviewed. Dogs were assigned to one of the following groups according to the final diagnosis: Non-Neurologic, Brain, Cervical Spine, Multifocal, and Chiari-like Malformation/Syringomyelia. Demographic data, clinical and neurological signs and laboratory findings were compared between groups using univariate analysis; predictors of disease location were assessed by multivariate analysis. RESULTS: Final diagnostic allocations of the 185 records included in the study were as follows: 2.7% Non-Neurologic, 2.2% Brain, 63.2% Cervical Spine, 22.2% Multifocal and 9.7% Chiari Malformation/Syringomyelia. Intervertebral disc extrusion and steroid-responsive meningitis arteritis were the most common diseases. Compared to Multifocal dogs, those allocated a Cervical Spine diagnosis were older, heavier, more frequently ataxic and lame on a thoracic limb; furthermore, they were less frequently depressed or hyperthermic at presentation. Leucocytosis, neutrophilia and monocytosis were more frequent in dogs allocated a Multifocal diagnosis. Dogs with cervical hyperaesthesia older than 36 months and non-hyperthermic at presentation were more likely to have a lesion of the cervical region rather than a multi-focal disease. CLINICAL SIGNIFICANCE: Although non-specific, these results may be useful to guide clinicians in management of dogs presenting with cervical hyperaesthesia. Animal age and body temperature may support the suspicion of either focal or multi-focal cervical spinal disease.

Effect of 5% transdermal lidocaine patches on postoperative analgesia in dogs undergoing hemilaminectomy.

OBJECTIVES: To investigate the effect of 5% lidocaine patches on postoperative analgesia in dogs undergoing hemilaminectomy. MATERIALS AND METHODS: Client-owned dogs undergoing hemilaminectomy for a single acute intervertebral thoracolumbar disc extrusion were enrolled in this prospective, randomised, blinded clinical trial. Following methadone administration, anaesthesia was induced with propofol, and maintained with isoflurane in oxygen and fentanyl infusion, in both groups. After skin closure, two 1∙5 cm wide 5% lidocaine patch strips were attached along both sides of the wound in dogs allocated to Group L. In Group C, the two lidocaine patch strips were applied but the transparent isolating liner was not removed. Postoperatively, all dogs received a non-steroidal anti-inflammatory drug, gabapentin and diazepam. Methadone was administered according to the short form of Glasgow Composite Pain Scale with pain assessed every 2 hours for 48 hours by observers unaware of the treatment. RESULTS: Thirty-nine dogs completed the study. Demographic data, end-expiratory fraction of isoflurane, fentanyl consumption, anaesthesia and surgical times were similar between groups. The number of dogs requiring postoperative methadone and the number of doses of methadone administered were not different between groups. No macroscopic skin reaction was noticed once the patches were removed. CLINICAL SIGNIFICANCE: In this setting, 5% lidocaine patches did not provide additional postoperative analgesia in dogs undergoing hemilaminectomy.

A preliminary study for the production of high specific activity radionuclides for nuclear medicine obtained with the isotope separation on line technique.

Radiopharmaceuticals represent a fundamental tool for nuclear medicine procedures, both for diagnostic and therapeutic purposes. The present work aims to explore the Isotope Separation On-Line (ISOL) technique for the production of carrier-free radionuclides for nuclear medicine at SPES, a nuclear physics facility under construction at INFN-LNL. Stable ion beams of strontium, yttrium and iodine were produced using the SPES test bench (Front-End) to simulate the production of 89Sr, 90Y, 125I and 131I and collected with good efficiency on suitable targets.

Retrospective clinical evaluation of hypobaric spinal anaesthesia in dogs undergoing pelvic limb orthopaedic surgery.

OBJECTIVE: To evaluate intraoperative effects, complications, postoperative rescue analgesia requirement and presence of postoperative unilateral blockade after hypobaric spinal anaesthesia in dogs. METHODS: Retrospective review of case records of dogs that underwent pelvic limb orthopaedic surgery and received hypobaric spinal anaesthesia. Cases that contained complete information on perioperative analgesia, end tidal anaesthetic agent, arterial blood pressure, postoperative urination, motor function and assessment at the sixth week re-examination were selected. RESULTS: Twenty-four of forty-eight records were sufficiently complete to meet the selection criteria. Local anaesthetic dose and volume of the solution administered were 0 · 22 (±0 · 06) mg/kg and 0 · 16 (±0 · 05) mL/kg, respectively. Fentanyl was administered intraoperatively in seven dogs (29%); mean ± sd end-expired isoflurane was 1 · 09 ± 0 · 17%; hypotension was observed in nine dogs (37 · 5%). Unilateral blockade was documented in 18 dogs (75%); 6 dogs (25%) required methadone postoperatively; urinary retention was not observed. One dog developed steroid responsive meningitis arteritis. CLINICAL SIGNIFICANCE: Hypobaric spinal anaesthesia achieved unilateral postoperative pelvic limb motor blockade in dogs, although bilateral block occurred in a proportion of animals; intraoperative hypotension was not infrequent. Fentanyl and postoperative methadone might be required to control nociception and pain, despite technical success in performing spinal anaesthesia.

Retrospective comparison of two peripheral lumbosacral plexus blocks in dogs undergoing pelvic limb orthopaedic surgery.

OBJECTIVES: To compare the lateral pre-iliac approach to the lumbar plexus combined with lumbar paravertebral sciatic nerve block, and the dorsal paravertebral approach to the lumbar plexus combined with sciatic nerve block in dogs. METHODS: Retrospective examination of case records of dogs that received the blocks and underwent pelvic limb orthopaedic surgery between 2010 and 2012. Success rate (intraoperative fentanyl consumption <2·1 µg/kg/hour), type and dose of local anaesthetic used, multiple of minimum alveolar concentration of volatile anaesthetic agent administered, incidence of intraoperative hypotension, postoperative methadone administration, postoperative contralateral limb paralysis and neurological complication at 6 weeks re-examination were analysed. RESULTS: Ninety-six and 95 records were retrieved in which lateral pre-iliac - lumbar paravertebral sciatic nerve and dorsal paravertebral - sciatic nerve were used, respectively. Success rates were 82·3% in lateral pre-iliac - lumbar paravertebral sciatic nerve and 74·7% in dorsal paravertebral - sciatic nerve groups. Bupivacaine, levobupivacaine and ropivacaine were used. Total local anaesthetic doses, intraoperative hypotension and postoperative methadone administered were similar between groups; minimum alveolar concentration multiple was significantly (P<0·001) lower in lateral pre-iliac - lumbar paravertebral sciatic nerve group. No neurological complications were noted. CLINICAL SIGNIFICANCE: Although success rates and perioperative analgesic requirements were not significantly different, the different exposure to anaesthetic agents suggests that the two techniques may not be equivalent.

Peripheral nerve blocks of the pelvic limb in dogs: a retrospective clinical study.

OBJECTIVE: To evaluate the success rate and complications of lumbar plexus (LP) and femoral nerve (FN) blocks, each combined with a sciatic nerve (SN) block, in dogs undergoing pelvic limb orthopaedic surgery. DESIGN: Retrospective clinical study. PROCEDURE: The intra-operative and postoperative clinical records of dogs that underwent orthopaedic surgery of the pelvic limb were reviewed. Dogs were divided into two groups according to the analgesic technique used during surgery: dogs that received a peripheral nerve block (group PNB) and dogs in which opioid analgesia alone was used (group C). RESULTS: The PNB and C groups included 265 and 31 dogs, respectively. Complete statistical analysis was performed in 115/265 dogs of PNB group. The overall success rate of the PNB performed was 77% (89/115): 76% (72/95) and 85% (17/20) for LP-SN and FN-SN blocks, respectively. In group PNB, the prevalence of intra-operative hypotension was 7.8% (9/115). Only one (out of 95 [1.05%]) LP-SN block manifested transient postoperative bilateral pelvic limb paralysis. None of the 265 dogs in group PNB manifested neurological complications at six weeks postoperatively. CONCLUSION: The success rate and the absence of neurological complications obtained support the use of LP-SN and FN-SN for loco-regional anaesthesia and analgesia in dogs undergoing orthopaedic surgery of the pelvic limb.

A comparison of the sedative and analgesic properties of pethidine (meperidine) and butorphanol in dogs.

OBJECTIVES: To compare the analgesic and sedative effects of butorphanol and pethidine (meperidine) in dogs. METHODS: Twenty-eight female dogs undergoing ovariectomy (20) or ovariohysterectomy (8) were randomly divided into two groups. Pre-anaesthetic medication in group B consisted of 20 µg/kg intramuscular (im) acepromazine and 0·4 mg/kg butorphanol, while group P received 20 µg/kg acepromazine with 5 mg/kg pethidine. The resulting sedation (simple descriptive scale), propofol dose required to induce anaesthesia, several intraoperative cardiorespiratory variables and postoperative pain (Colorado Pain Scoring System) were compared between the two groups. A 0·2 mg/kg meloxicam dose was administered intravenously to all animals at the end of the 4 hours observation period, or earlier if the pain score was more than 13. RESULTS: Sedation scores, propofol induction doses and intraoperative cardiorespiratory variables were not different between groups. Postoperative pain scores were also similar although one dog in group B required rescue analgesia. Five dogs in group P vomited postoperatively. CLINICAL SIGNIFICANCE: Either butorphanol and pethidine, combined with acepromazine, produced reliable sedation and analgesia up to 4 hours after intramuscular injection in dogs.

Pharmacokinetics, intraoperative effect and postoperative analgesia of tramadol in cats.

Tramadol is a synthetic codeine analogue used as an analgesic in human and veterinary medicine, but not approved for use in cats. Tramadol (2 mg/kg) was administered intravenously (IV) as preoperative analgesic in 12 cats (6 males) undergoing surgical gonadectomy. The pharmacokinetic profile of the drug and its O-desmethyl metabolite were determined in 8 animals (4 males), while intraoperative effects and postoperative analgesia, estimated by subjective pain score (0-24), were evaluated in all. Mean intraoperative isoflurane consumption was reduced, but hypoventilation was not observed. Sex-related differences were not observed, particularly in terms of postoperative analgesia: rescue analgesic was never administered. Concentrations of the active O-desmethyl metabolite were persistently high in all the animals. Considering the results obtained in this study, tramadol, at the dose of 2 mg/kg IV, did not produce any evident intraoperative cardiorespiratory side effects and with additional investigation may prove to be an appropriate intraoperative analgesic in cats undergoing gonadectomy.

A comparison of four systems for scoring recovery quality after general anaesthesia in horses.

REASON FOR PERFORMING STUDY: The recovery quality scoring systems (RQSSs) in current use have not been critically reviewed for reliability. OBJECTIVE: To examine reliability (reproducibility) of 4 RQSSs when applied to a ranked series. METHODS: A DVD incorporating the recordings of 9 horses recovering from general anaesthesia was evaluated by final year students over 5 days. On Day 1, each evaluator ranked recoveries from 1-9 (1 = best). Over the following 4 days, each evaluator scored the same recoveries using 4 different RQSSs (3 of them in common usage and previously published) applied in random order. The scores from each RQSS were ranked and plotted against the Day 1 ranking of each evaluator to establish the extent of agreement using generalisability theory. The same 9 recoveries were also ranked by 12 experienced equine anaesthetists and the Spearman Rank Correlation coefficient calculated to determine the agreement between experienced and inexperienced evaluators. RESULTS: The recoveries were evaluated by 117 students. All 4 RQSSs were equally reliable with low (<4%) interobserver variability. The main (80%) source of total variation arose from differences between horses. The overall ranking within each RQSS was strongly correlated with Day 1 ranking. There was strong correlation (r = 0.983) between the students' ranking and that established by experienced anaesthetists. Interobserver reliability was similar with all 4 RQSSs. CONCLUSION: All 4 RQSSs studied were similarly reliable. POTENTIAL RELEVANCE: The selection of a universally acceptable RQSS from amongst the 4 examined can be based on criteria other than reliability, e.g. ease of use. This will facilitate wider scale multi-centre studies in recovery quality after anaesthesia in horses.