Juliet Duncan

The bispectral index during recovery from halothane and sevoflurane anaesthesia in horses

OBJECTIVE To record the bispectral index (BIS) when horses moved during either halothane or sevoflurane anaesthesia and when they made volitional movements during recovery from these anaesthetics. STUDY DESIGN Randomized prospective clinical study. ANIMALS Twenty-five client-owned horses undergoing surgery aged 8.8 (± 5.3; 1-19) years (mean ± SD; range). METHODS Baseline BIS values were recorded before pre-anaesthetic medication (BISB) and during anaesthesia (BISA) maintained with halothane (group H; n = 12) or sevoflurane (group S; n =13) at approximately 0.8-0.9 × minimum alveolar concentrations (MAC). Bispectral indices were recorded during the surgery when unexpected movement occurred (BISMA), during recovery when the first movement convincingly associated with consciousness was observed (BISM1) and once sternal recumbency was achieved (BISST). RESULTS No significant difference in BISM1 was found between halothane- (85 ± 7; 75-93) and sevoflurane- (87 ± 10; 70-98) anaesthetized horses although BISA was significantly (p = 0.0002) lower in group S (62 ± 7; 53-72) than group H (74 ± 7; 60-84). Differences between BISM1 and BISA were significant in sevoflurane (p = 0.00001) and halothane recipients (p = 0.002) but were greater in group S (25 ± 9; 4-38) compared with group H (12 ± 10; -9-25). In six of eight horses, BISMA values ranged between those recorded during anaesthesia and at first movement. CONCLUSIONS AND CLINICAL RELEVANCE Bispectral indices appear to approximate levels of unconsciousness, suggesting that monitoring the BIS may assist equine anaesthesia. However, it does not predict intra-operative movement.

Drawing the line in clinical treatment of companion animals: recommendations from an ethics working party

Modern veterinary medicine offers numerous options for treatment and clinicians must decide on the best one to use. Interventions causing short-term harm but ultimately benefitting the animal are often justified as being in the animal’s best interest. Highly invasive clinical veterinary procedures with high morbidity and low success rates may not be in the animal’s best interest. A working party was set up by the European College of Veterinary Anaesthesia and Analgesia to discuss the ethics of clinical veterinary practice and improve the approach to ethically challenging clinical cases. Relevant literature was reviewed. The ‘best interest principle’ was translated into norms immanent to the clinic by means of the ‘open question argument’. Clinical interventions with potential to cause harm need ethical justification, and suggest a comparable structure of ethical reflection to that used in the context of in vivo research should be applied to the clinical setting. To structure the ethical debate, pertinent questions for ethical decision-making were identified. These were incorporated into a prototype ethical tool developed to facilitate clinical ethical decision-making. The ethical question ‘Where should the line on treatment be drawn’ should be replaced by ‘How should the line be drawn?’

Management of an anaphylactoid crisis due to mast cell degranulation in a dog during general anaesthesia

It is widely stated within the veterinary literature that manipulation of a mast cell tumour can lead to an anaphylactoid reaction; however, there is limited information on the frequency or management of such cases in companion animals. A nine-year-old, 38.4 kg, female neutered, labrador (retriever) presented for excision of a cutaneous mast cell tumour located on the left lower eyelid. This report describes a Grade III anaphylactoid crisis (hypotension, bradycardia and bronchospasm) that occurred when the dog was under general anaesthesia following mast cell degranulation. Prompt management following fluid resuscitation, administration of an aerosolised bronchodilator and intravenous atropine, successfully addressed the underlying pathophysiology of anaphylactoid crisis.

Pets in clinical trials

We have been concerned for some time with an apparent progressive loss of clarity between acts of veterinary surgery and animal experimentation, particularly with respect to companion animals. Our concerns were heightened by an editorial published in Nature in December 2016 entitled ‘Pet projects need a helping hand’ (Anon 2016). This article proposed that the EU directive 2010/63 be relaxed so that veterinarians can conduct clinical trials on pet animals. In the editorial, it was suggested that ‘overzealous regulations’ are stifling scientific progress by limiting the use of companion animals in clinical trials of treatments of both human and animal disease. While we accept the possibility of some benefit arising from such studies, we feel Nature significantly underestimates the potential for harms to be caused to the animals used. We argue that robust regulation is necessary for clinical trials carried out using companion animals, just as it is for all scientific uses of animals and for human clinical trials. Indeed, ethical oversight for trials on companion animals which involve the potentially competing interests of animals, owners, treating clinicians and trial funders may be in even more need of independent ethical review and oversight than most other forms of animal research. The editorial suggests that using pets for clinical trials is scientifically more valid because they are the ‘real McCoy’: they are genetically diverse, develop …

Comparison of anaesthesia ‘Day 1 skills’ expectations between veterinary anaesthetists and general practitioners

Day One Skills (DOS) were introduced by the Royal College of Veterinary Surgeons (RCVS) in 2006 as a guideline for minimum skills required by a veterinary graduate. However, the RCVS anaesthesia DOS are broad and do not specify differences in skills required for different species. The aims of this study were: (1) to determine which anaesthesia skills were considered essential for day one practice by UK-based veterinary practitioners (GPs) and anaesthetists; and (2) to explore current opinions on veterinary undergraduate anaesthesia training. Questionnaires for veterinary GPs (QGPs) and veterinary anaesthetists (QVAs) were developed which asked general information on expectations of anaesthesia skills as well as specific expectations for the common veterinary species. Fifty-five UK-based members of the Association of Veterinary Anaesthetists responded, with a random sample of veterinary practices stratified by UK county generating 234 responses and a convenience sample targeted at more specialist veterinary specialities in the UK generating 161 responses. There was close overall agreement between the two groups of GPs and anaesthetists on essential anaesthesia DOS. However, expectations varied with species—greatest in cats and dogs, lowest in exotics. Many respondents commented that new veterinary graduates lack practical skills and should not be expected to be omnicompetent across all species. In conclusion, anaesthesia undergraduate training should prioritise essential practical DOS.