The importance of keeping patients warm
Published 22/10/2016 | 00:00
There has always been a steady trickle down of improved knowledge and techniques from human medical advances to the veterinary world. This does not always happen, for a number of reasons.
First, some human diseases are so radically different from the animal equivalents that innovative treatments aren't always relevant.
Second, some human treatments are so costly that their use in the veterinary world isn't economically feasible. The use of cochlear implants to give hearing back to a deaf person is an example: very few dog owners are prepared to stump up €20000 per ear to give their pet the chance of hearing again.
Third, even short periods of extra life are highly valued for humans, and medical science is geared to give everyone as long a life as possible, despite the ongoing hurdles that a disease may throw up along the way. In the veterinary world, quality of life is valued over length of life: animals live in the moment, savouring the present rather than reflecting on the future as humans do. So if an animal has a disease involves continual discomfort despite treatment, euthanasia is an option that many owners will choose. This is why complex treatments for chronic diseases are not used as commonly in the veterinary world.
Despite these three exceptions, there are many examples where veterinary medicine follows in the footsteps of medicine. I suspect that animals benefit from medical advances around a decade after they've become widespread in the human world. Examples include diagnostic imaging, such as CAT and MRI scans, and some chemotherapies for cancer treatments.
Vets also follow doctors in many practical areas of their work. One area that has come to my attention recently involves the monitoring of body temperature of patients during and after surgical operations.
Traditionally, this was always left to common sense. We've always known that animals are prone to chilling if steps are not taken to keep them warm during operations, and as they recover from surgery. Soft, insulated bedding is placed beneath them, rather than setting them up on the plain metal of an operating table. And warm blankets are placed over patients when they are returned to their recovery kennels after operations, until they are fully awake.
More recently, a rigorous scientific approach has been taken to assessing the impact of body temperature in patients. Human medics discovered if the body temperature is not monitored very closely, hypothermia can still occur, resulting in prolonged recovery times after anaesthesia, extended hospitalisation times, increased bleeding and infection at operation sites, and a depressed immune system. Additionally, patients suffer the physical signs of shivering and discomfort. For these reasons, efforts to keep patients warm have been stepped up in the human medical world.
Veterinary researchers decided to investigate the scale of these issues in animals, taking temperatures at different phases of hospital visits: before anaesthesia, during the operation, at the end of the operation, when the patient wakes up, and finally, a few hours later when the patient is ready to go home. The results were sobering: nearly 90% of dogs and almost 100% of cats were found to be suffering from some degree of hypothermia. These figures are high compared to humans: only 30 to 60% of humans suffer from some chilling after operations. This means that animals have a higher risk than humans of complications caused by hypothermia.
When this research was published, vets started to tackle the problem more seriously. Body temperature is now measured more regularly, and all veterinary staff are acutely aware of the need to focus on keeping pets warm before, during and after surgery.
It's possible to buy special warming devices, such as warm air blowers, heated water-filled mattresses and warm chambers, but studies have shown that these are often not necessary. Instead, simple steps suffice.
Anaesthetised patients should be kept off the cold surfaces made of metal, rubber and plastic at all times, instead being allowed to lie on blankets. When fluids are used for the patient (e.g. given directly as intravenous drips, or applied to the animal as a way of cleaning the operation site), these should be warmed first, where possible.
Blankets should be used at all times, beneath and on top of the patient: there are many types of fabric that can be used. Ideally, the blankets should be warmed first (e.g. in a tumble drier).
Direct heat - such as hot water bottles - has to be used with caution, as it's easy to burn an anaesthetised animal (they cannot move away if something is too hot).
The final part of this challenge is the most important: monitoring the temperature. The only way that you can tell if an animal is getting chilled is by measuring their body temperature. Through a process known as "clinical audit", many vets now monitor their clinic rates of optimal temperature in their patients, continually aiming to improve their patient care.
Minimising patient chilling is just one of many lessons that vets have learned from our medical doctor colleagues.