Anaesthesia for the geriatric dog and cat

380 peer reviewed Introduction Our veterinary patients are better cared for now than ever before and therefore, rather like human beings, they are living longer. In addition, the range of medical and surgical interventions is forever increasing, so most small animal veterinary surgeons will anaesthetise several geriatric patients every week. There are two main causes of increased anaesthetic morbidity and mortality in the geriatric patient. The first of these is age-related concurrent disease. In people, this is the main cause of increased mortality (Muravchick, 1998) and there is no reason to suspect it is any different in animals. This makes pre-anaesthetic assessment of our patients of paramount importance. Secondly, anaesthetic morbidity is increased because of a decline in organ function or reserve – the so-called ‘elderly normal’ patient. Under routine nonstressful conditions, the physiological changes that occur in body composition, the brain, kidney, liver, heart and lungs produce no or only minimal functional impairment. However, with acute disease or surgery, and hence stress, the diminished reserve capacity of elderly patients impairs their response to increased demand (Conzen and Peter, 1995). This article covers the following topics: definition of the geriatric dog and cat; • the ageing process; how this affects physiological • responses under anaesthesia and places the geriatric patient at increased risk; how pre-anaesthetic assessment and stabilisation can • improve the outcome when anaesthetising the geriatric patient; methods of anaesthetising the older patient and • providing care in the post-operative period; and, a summary of recommendations. •