Retrospective computed tomography analysis of endotracheal tube constriction & mispositioning in cats & dogs

Objectives: To discover the prevalence of endotracheal tube (ETT) constriction and rostral and caudal mispositioning in anaesthetised cats and dogs, and to identify associated risk factors. Study Design: Retrospective analysis. Animal population: A total of 146 cats, 670 dogs. Methods: Computed tomography images of the head/neck/thorax from orotracheally intubated cats and dogs were visually assessed for constriction or mispositioning of the ETT. If constriction was present, measurements of the cross-sectional area (CSA) of the ETT lumen at constricted and un-constricted locations were compared. Location and cause of constriction were noted and the expected increase in resistance to gas flow was calculated. Animal information was collected from clinical records. Normality of continuous variables was assessed via the Shapiro-Wilk test. Chi square tests examined associations between variables. Kendall’s tau-b test was performed between measured ETT size and degree of constriction. Results: The ETT extended rostrally beyond incisors in 52% of cases; the connector was within the oral cavity in 19% of cases. The ETT extended beyond the first rib in 25.5% of cases. The prevalence of ETT constriction was 22.7%. Median reduction in CSA was 7.68% (0.14–64.19%). Median increase in resistance assuming laminar and turbulent flow was 16.5% (0.3–680%) and 21% (0.3–1200%), respectively. The most common cause of constriction was the presence of a radiotherapy mouth gag. Significant associations existed between presence of constriction and rostral mispositioning, and caudal mispositioning and extreme brachycephaly. Increased severity of constriction was more likely in smaller ETT. Conclusions: And clinical relevance Constriction and mispositioning of ETT occurred very commonly in this population. Checking the ETT within the oral cavity for constriction and mispositioning is recommended. Radiotherapy mouth gags increase the risk of ETT compression. Smaller ETT are at greater risk of severe constriction. Brachycephalic dogs are at particular risk of caudal mispositioning

Delayed dyspnoea in pigs possibly associated with endotracheal intubation

No abstract available

Monitoring small animal anaesthesia: Where are we now?

No abstract available

Managing patients' pain

HANDBOOK OF VETERINARY PAIN MANAGEMENT, 2ND EDN Gaynor, James S. and Muir, William W. 672 pages, softback, £30.99. Mosby Elsevier. 2008. ISBN 978 0 323 04679

Attitudes of dog owners in Edinburgh towards canine blood donation

The establishment of animal blood banks following legislative changes in the UK in 2005 has led to increasing accessibility and use of animal blood products. However, the supply of animal blood is currently not meeting demand. This study aims to identify potential methods of increasing donor recruitment to meet this demand. A questionnaire was constructed, consisting of three sections designed to evaluate owner perceptions, identify incentives for donation and to obtain demographic data. Seventy-nine responses were included, 76 of which were previous non-donors. The top three reasons for not donating in this group were uncertainty over where to donate, veterinarians not expressing the need for donors and lack of awareness. Considering these results, one method of potentially increasing donor recruitment is encouraging more veterinarians to actively advertise local donor programmes. Emphasising the mandatory inclusion of a free annual health check in the donor process may also be helpful as many respondents rated this highly. It is the authors’ hope that this preliminary data may lead to increased willingness of owners to nominate their dogs for donation by guiding the provision of appropriate incentives and education to quell owner concerns as highlighted by this study

Accuracy of fluid infusion pumps using different administration sets: preliminary observations

No abstract available

Investigating the effect of anxiety on pain scores in dogs

Objective: To investigate the relationship between anxiety and pain scores using the Glasgow Composite Measure Pain Scale–Short Form (CMPS-SF) in dogs. Study: Prospective observational study. Animals: A group of 18 dogs undergoing surgical management of stifle disease. Methods: Preoperatively dogs were scored using the CMPS-SF, the anxiety behaviour-based Reactivity Evaluation Form (REF), a Visual Analogue Scale (VAS) for anxiety and a sedation score. Assessments of pain, anxiety and sedation were repeated approximately 2–6 hours postoperatively. Dogs were divided into groups based on preoperative REF (‘Low REF’ and ‘High REF’), and VAS scores (‘Low VAS’ and ‘High VAS’). Scores (CMPS-SF, REF, VAS and sedation) were compared between groups using Mann–Whitney U tests. Preoperative and postoperative CMPS-SF, REF and VAS scores were compared using Wilcoxon signed-rank tests. Relationships between anxiety and CMPS-SF scores were assessed using a Spearman rank correlation coefficient. Scores are presented as median (range). A p value of < 0.05 was considered significant. Results: When divided based on REF, CMPS-SF scores did not differ between groups preoperatively [Low REF: 2 (0–3), High REF: 2 (1–3); p = 0.509] or postoperatively [Low REF: 3 (2–5), High REF: 3 (2–5); p = 0.624]. When divided based on VAS, CMPS-SF scores did not differ between groups preoperatively [Low VAS: 2 (0–2), High VAS: 2 (1–3); p = 0.215] or postoperatively [Low VAS: 3 (2–5), High VAS: 3 (2–5); p = 1]. Postoperative REF [pre: 4.5 (2–8), post: 5 (4–10); p = 0.0105] and CMPS-SF scores [pre: 2 (0–3), post: 3 (2–5); p = 0.0318] increased significantly compared with preoperative scores. Conclusions and clinical relevance: No apparent relationship exists between baseline anxiety levels and CMPS-SF scores. Understanding the influence of anxiety when using the CMPS-SF is important when assessing pain in dogs. Anxiety and pain may increase postoperatively in dogs undergoing orthopaedic surgery

Automatic ventilators

Automatic ventilators enable the provision of intermittent positive pressure ventilation (IPPV) to support ventilation in anaesthetized or heavily sedated patients. An automatic ventilator is an invaluable tool that provides repeated, controlled breaths, so allowing the anaesthetist to attend to other aspects of patient monitoring and support. This chapter deals with indications for IPPV, when to initiate IPPV, physiological effects of IPPV, classification of automatic ventilators and their practical use

Complete tracheal obstruction during anaesthesia for ventral slot decompression surgery in a dog

An 8-year-old, female Yorkshire terrier presented to the neurology department with a 3-month history of progressive ambulatory tetraparesis. A diagnosis of intervertebral disc protrusions at the levels of C3–C4 and C6–C7 was made using magnetic resonance imaging. Ventral slot decompressive surgery was carried out at both sites. When accessing the C6–C7 disc space, placement of Gelpi retractors resulted in complete tracheal obstruction, characterised by an absence of end tidal carbon dioxide measurement. This occurred in conjunction with the cessation of abdominal and thoracic respiratory movement despite the use of positive pressure ventilation. Removal of the Gelpi retractors resolved the tracheal occlusion and permitted the resumption of ventilatory support. To facilitate this surgical approach, the trachea was reintubated with a longer endotracheal tube to protect the patency of the airway. To the authors’ knowledge, this is the first report of tracheal obstruction as a complication of a ventral slot procedure

Possible delayed respiratory depression following intrathecal injection of morphine and bupivacaine in an alpaca

OBJECTIVE: To describe general anesthesia and successful treatment of an alpaca, which developed respiratory arrest 2 hours after intrathecal injection of morphine and bupivacaine. CASE SUMMARY: A 10-day-old female alpaca weighing 7.3 kg was presented to our hospital with a fractured right tibia. The cria was anesthetized to repair the fracture with a dynamic compression plate. Anesthesia was induced with IV propofol and maintained with sevoflurane in 100% oxygen. Prior to the start of surgery the alpaca received an unintended intrathecal injection of 0.6 mL of a solution of 0.5 mg morphine (0.068 mg/kg) and 1.5 mg bupivacaine (0.2 mg/kg), after an attempted lumbo-sacral epidural. The alpaca developed respiratory arrest 120 minutes after the intrathecal injection was administered. Adequate hemoglobin-oxygen saturation was maintained despite minimal intermittent manual ventilation, but marked hypercapnia developed (PaCO2 of 17.3 KPa [130 mm Hg]). Delayed respiratory depression resulting from cephalad migration of intrathecal morphine was suspected. Ventilation was supported until the end of surgery when sevoflurane was discontinued. The trachea remained intubated, 100% oxygen was supplied, and ventilation was supported at 2-4 breaths/min for the next 60 minutes, but no attempts to breathe spontaneously were detected. Intravenous naloxone (0.3 mg [0.04 mg/kg]) was administered slowly to effect until adequate spontaneous ventilation and full consciousness returned. The anesthetic recovery of the alpaca was rapid and uneventful after the opioid antagonist was given. NEW INFORMATION PROVIDED: Delayed respiratory depression is a potential complication after intrathecal administration of morphine. Careful dose-adjustment may reduce the risk, and close monitoring will result in early detection and treatment of this complication