No abstract

Summary Our objective was to test the hypothesis that the prevalence and type of post‐operative equine morbidity at a single centre does not change over time with a retrospective and prospective observational study. The post‐operative case records of 92 (of 96) horses undergoing nonabdominal procedures, and surviving to discharge, were compared with previous data from the same centre. Predefined morbidities were recorded from horses undergoing surgery between August 2013 and July 2014. This was compared with data collected from the same institute from April 2004 to June 2005 and published in a previous study. The overall prevalence of morbidities increased from 13.4% to 25%. The prevalence of post‐anaesthetic colic, thrombophlebitis, pyrexia, lameness, neuropathy and myopathy increased while the proportion of incidence of diarrhoea, respiratory distress and wounds sustained in recovery decreased. There was a statistically significant association (P = 0.045) between the duration of surgery and the prevalence of post‐anaesthetic colic. Geldings were less likely (odds ratio 0.12, 95% confidence interval 0.02–0.84) to develop swelling at the catheter site and the likelihood of thrombophlebitis increased by 1.20 (95% confidence interval 1.01–1.41) for every year of life. Tracking morbidities and changes in their prevalence may elucidate their possible causation and allow prophylactic measures to be taken.

Intravenous fluid therapy is routinely administered to animals during the perianaesthetic period. The purpose of fluid therapy is the maintenance of circulating blood volume, arterial blood pressure and tissue perfusion. In addition, fluid administration aims to meet losses due to ventilation and urinary production. Current guidelines for maintenance fluid rates are 5 ml/kg/h in dogs and 3 ml/kg/h in cats. These doses are considerably less that the 10 m/kg/h used previously. Studies have demonstrated that iatrogenic fluid overdose leads to perianaesthetic mortality in humans, while studies using more restrictive rates of fluid administration have shown shorter duration of hospitalisation and faster return of gastrointestinal motility. Assessment of hypovolaemia is challenging; changes in heart rate and arterial blood pressure are commonly used; however, these indicators are relatively insensitive indicators of hypovolaemia. Goal-directed therapy is advocated, using pulse-pressure variation and systolic-pressure variation. Treatment options for fluid therapy include crystalloids and colloids. Crystalloids are used to treat deficits in the extracellular fluid volume. Colloids may be used to support intravascular fluid deficits. However, evidence-based guidelines for the selection of different fluid types are not clearly defined. Fluid therapy plans should be tailored to the needs of an individual animal.

V-gels® (Docsinnovent Ltd, UK) are the first veterinary supraglottic airway devices (SADs) that have been developed. They can be used as an alternative to endotracheal intubation. Species that would benefit from the use of v-gels include cats and rabbits. In both species orotracheal intubation may be difficult, due to specific anatomical features in lagomorphs and due to laryngospasm in cats. As a result of difficulties related to rabbit intubation, anaesthesia is often induced and maintained with a facemask, which commonly leads to inadequate ventilation. Rapid achievement of a secure airway allows mechanical ventilation should hypoventilation or apnoea occur — common problems following anaesthetic induction in rabbits and cats. In patients where endotracheal intubation is not possible, v-gels can provide a secure and patent airway, enable intermittent positive pressure ventilation and reduce the environmental contamination with anaesthetic gases. Use of capnography is highly advisable with SADs, as this will provide rapid notification if the device becomes dislodged or blocked, in addition to providing useful information regarding patient ventilation and cardiovascular status.