Induction dose and recovery quality of propofol and alfaxalone with or without midazolam coinduction followed by total intravenous anesthesia in dogs.

OBJECTIVES: To compare propofol and alfaxalone, with or without midazolam, for induction of anesthesia in fentanyl-sedated dogs, and to assess recovery from total intravenous anesthesia (TIVA). STUDY DESIGN: Prospective, incomplete, Latin-square study. ANIMALS: Ten dogs weighing 24.5 ± 3.1 kg (mean ± standard deviation). METHODS: Dogs were randomly assigned to four treatments: treatment P-M, propofol (1 mg kg-1) and midazolam (0.3 mg kg-1); treatment P-S, propofol and saline; treatment A-M, alfaxalone (0.5 mg kg-1) and midazolam; treatment A-S, alfaxalone and saline, administered intravenously (IV) 10 minutes after fentanyl (7 µg kg-1) IV. Additional propofol or alfaxalone were administered as necessary for endotracheal intubation. TIVA was maintained for 35-55 minutes by infusions of propofol or alfaxalone. Scores were assigned for quality of sedation, induction, extubation and recovery. The drug doses required for intubation and TIVA, times from sedation to end of TIVA, end anesthesia to extubation and to standing were recorded. Analysis included a general linear mixed model with post hoc analysis (p < 0.05). RESULTS: Significant differences were detected in the quality of induction, better in A-M than A-S and P-S, and in P-M than P-S; in total intubation dose, lower in P-M (1.5 mg kg-1) than P-S (2.1 mg kg-1), and A-M (0.62 mg kg-1) than A-S (0.98 mg kg-1); and lower TIVA rate in P-M (268 µg kg-1 minute-1) than P-S (310 µg kg-1 minute-1). TIVA rate was similar in A-M and A-S (83 and 87 µg kg-1 minute-1, respectively). Time to standing was longer after alfaxalone than propofol, but was not influenced by midazolam. CONCLUSIONS AND CLINICAL RELEVANCE: Addition of midazolam reduced the induction doses of propofol and alfaxalone and improved the quality of induction in fentanyl-sedated dogs. The dose rate of propofol for TIVA was decreased.

DISTRIBUTION AND SHORT- AND LONG-TERM EFFECTS OF INJECTED GELIFIED ETHANOL INTO THE LUMBOSACRAL INTERVERTEBRAL DISC IN HEALTHY DOGS.

Radiopaque gelified ethanol preparation has been described as a useful agent for treatment of humans with intervertebral disc protrusion. The material is injected into the nucleus pulposus under image guidance with intention to cause the protruded disc material to recede. Because treatment options for dogs with chronic protrusions are limited, new and minimally invasive treatments are desirable. The aim of this experimental, descriptive, prospective study was to assess the feasibility and safety of percutaneous injection of gelified ethanol into the lumbosacral intervertebral disc of dogs. Lumbosacral intervertebral discs of normal dogs (n = 9) were imaged with magnetic resonance imaging and then injected with gelified ethanol using image guidance. The accuracy of gelified ethanol placement in the nucleus pulposus and presence of leakage of the injected material were documented. Postinjection computed tomography (CT) findings (n = 9), short-term (n = 9) and long-term (n = 4) follow-up magnetic resonance imaging and CT findings were compared to document the distribution of the injected preparation and identify effects on adjacent tissues. Percutaneous injection of the intervertebral disc was successful in delivering radiopaque gelified ethanol to the nucleus pulposus in all dogs. Leakage of the injected material into the vertebral canal was present in three dogs immediately following injection and in another additional dog at 1 year following injection. All dogs tolerated the injection well and had no clinical adverse reactions within the study period. Findings indicated that injection of the nucleus pulposus of healthy dogs was well tolerated, even in the presence of mild leakage of material from the intervertebral disc.

Intraobserver and interobserver reliability of standardized capillary refill time in dogs is high following observer training.

OBJECTIVE: To assess intraobserver and interobserver reliability of capillary refill time (CRT) measurement in dogs using a standardized technique after training. ANIMALS: 20 dogs presented to the emergency room. METHODS: Dogs presented to the emergency room were prospectively recruited. Using a timing device and standardized technique, CRT was measured at the oral mucosa of the inner lip. Measurements were performed by 2 emergency and critical care residents (observer 1 [Ob1] and observer 2 [Ob2]) and repeated 3 times by each observer for each dog. CRT values and signalment were recorded. Intraobserver and interobserver reliability were analyzed by calculation of the coefficient of variation (CV%), intraclass correlation coefficient (ICC), and minimal detectable difference. Reliability was considered high if CV% was lower than 10% and ICC was between 0.9 and 1. RESULTS: Median CRT for Ob1 was 1.22 seconds and for Ob2 was 1.19 seconds. Intraobserver reliability was high, evidenced by a median CV% of 6.2% (range, 1.0% to 18.6%) and 9.5% (range, 1.3% to 22.6%) and an ICC of 0.97 (95% CI, 0.94 to 0.99) and 0.95 (95% CI, 0.90 to 0.98) for Ob1 and Ob2, respectively. Between observers, the CV% was 4.4% (range, 0.8% to 17.5%) and the ICC was 0.98 (95% CI, 0.94 to 0.99), indicating high interobserver reliability. The minimal detectable differences for intraobserver and interobserver were 0.30 and 0.34 seconds, respectively. CLINICAL RELEVANCE: The reported high reliability of CRT despite its subjective nature enhances its usefulness in daily practice. However, further research on the validity of CRT is warranted.

Case report: Palliation of right pulmonary artery compression with overlapping, self-expanding vascular stents and toceranib phosphate in a dog with a large, compressive chemodectoma.

Acquired pulmonary artery branch stenosis without main pulmonary artery involvement due to external compression by neoplasia has been described in human and veterinary medicine. Over time, this can result in right ventricular hypertension and right-sided heart failure. Endovascular stenting offers quick relief from signs, while the underlying cause is addressed. Here, we present a dog with severe right pulmonary artery compression caused by a chemodectoma, which was treated with two, overlapping, self-expanding vascular stents and chemotherapy. The patient experienced immediate symptomatic relief, progressive stent expansion over time, and has been free of clinical symptoms for 5 months post implantation.

Description of a novel ultrasound-guided percutaneous dilatational esophagostomy tube placement in dog cadavers.

BACKGROUND: Nutritional support has become an essential part of modern veterinary medicine. Among different techniques, esophagostomy tubes have been used extensively in dogs and cats. However, general anesthesia is typically required due to the critical step of passing an instrument orally to allow identification of the esophagus in the midcervical region. Therefore, clinicians commonly face a conundrum of poor general anesthesia candidacy for those who need an esophagostomy tube placed. Additionally, esophagostomy tubes are not a viable option for patients that have difficulty opening their mouth. Ideally, a technique that circumvents the step of passing an instrument orally would be developed. KEY FINDINGS: We report the successful development of a novel technique for esophagostomy tube placement using ultrasound guidance and serial percutaneous dilatation of the stoma in canine cadavers. Ultrasound guidance allowed for identification and avoidance of several vital structures in the cervical region. SIGNIFICANCE: This is the first report of an esophagostomy tube placement technique that circumvents the step of passing any instrument orally to identify the esophagus in the midcervical region. Future studies are warranted to determine if this technique can be performed in live dogs.

Case report: Recovery and sequential imaging of a patient with osmotic demyelination syndrome.

A 4-year-old neutered-male Australian Shepherd was presented to an emergency and referral hospital for an acute onset of neurologic signs and abnormal mentation. Seven days prior, the patient had been diagnosed with hypoadrenocorticism and was treated accordingly at another hospital. Based on recent clinical history, the neurologic signs were consistent with thalamic and brainstem deficits and suspected to be caused by osmotic demyelination syndrome secondary to rapid correction of hyponatremia. A brain MRI confirmed lesions consistent with osmotic demyelination syndrome. The patient's clinical signs initially worsened, and he required intensive nursing care with multimodal sedation, close monitoring of electrolytes and tailored fluid therapy. The patient recovered and was discharged on day seven of hospitalization. Four and a half months later, re-evaluation of the patient showed complete resolution of the neurological deficits with a now unremarkable neurological exam, and follow-up MRI revealed still present, yet improved bilateral thalamic lesions. This is the first known veterinary case report of sequential brain imaging of a dog that has recovered from osmotic demyelination syndrome. In humans, patients can have evidence of near to full clinical recovery, yet imaging findings may still be abnormal several months after recovery. This report details similar imaging findings in a canine with improved clinical signs, despite persistent lesions on brain MRI. Prognosis of canines with osmotic demyelination syndrome may be better than previously perceived, despite the severity of clinical signs and brain lesions apparent on MRI.

Growth of adenocarcinoma from canine pleural fluid on aerobic bacterial culture.

We report a case of canine adenocarcinoma with multi-organ metastasis in which colonies of adenocarcinoma cells grew upon aerobic bacterial culture of pleural effusion. Stained agar colonies were highly similar to rare suspicious cells seen on cytologic examination of the pleural effusion, as well as rare cells seen on cytologic examination of pancreatic and gastric wall fine-needle aspirates. Cells from colonies growing on agar media were mildly immunoreactive for cytokeratin. Histologic examination of tissues obtained at autopsy revealed pancreatic adenocarcinoma with vascular invasion and nodal, gastric, pulmonary, and pleural metastasis.

Protective effect against focal cerebral ischemia injury in acute phase of a novel invasive device for regional hypothermia.

BACKGROUND: Systemic hypothermia is considered beneficial to stroke patients. However, many complications ensue. The aim of this study was to evaluate the effect of a new invasive regional cooling device in cerebral ischemic injury in a rat model. METHODS: After a pilot study confirming the efficiency of the cooling device, 15 adult male Sprague-Dawley rats, weighing 300-400 g, were randomly assigned into three groups: cooling device applied at 14°C and at 26°C, and a sham group. Focal cerebral ischemic injury was achieved by electrocauterization of the left middle cerebral artery through craniectomy and temporal occlusion of both common carotid arteries for 3 hours. Within 30 minutes after the end of ischemic injury, the cooling device was inserted into the rat brain through a stereotactic frame to provide regional hypothermia for 2 hours. The rats were sacrificed immediately after the 2-hour regional hypothermia. RESULTS: Although triphenyltetrazolium chloride staining showed smaller ischemic lesions in both the 26°C and 14°C groups compared to the control group, Fluoro Jade C staining showed no neuroprotective effects in the rostrum cerebral cortex in both groups. However, both triphenyltetrazolium chloride and Fluoro Jade C staining indicated significant beneficial effects in the caudal cerebral cortex in rats with cooling device applied at 26°C compared to the 14°C and control groups. CONCLUSION: Our findings indicated that the device can effectively achieve regional hypothermia and could be beneficial for patients with cerebral ischemia during the acute phase.