What is anaesthesia?
Loss of feeling or sensation. When we talk about anaesthesia today we usually imply general anaesthesia. This indicates a state of unconsciousness produced by drugs with the absence of any pain over the whole body together with variable amounts of muscle relaxation.
Are other types of anaesthesia used in animals and what are they?
Yes. Examples are local and spinal anaesthetics which are also used in certain circumstances.
Do you think we are silly to be so worried?
You are merely showing concern for your animal. All anaesthetics do carry some risk and each animal reacts differently. Over the last few years, there have been many improvements in safety and efficacy of anaesthetic drugs.
The anaesthetic agent is tailored for each animal. Age, state of health, procedure etc. are all individually considered.
We ask you to sign an anaesthetic consent form, not because we fear the worst but to emphasise that the procedure does carry some risk and that you have been made aware of these. You can rest assured that your pet will be monitored carefully throughout the procedure and the recovery period.
What happens when I bring my dog?
At the time of admittance, your dog will be carefully examined to check that no problem has arisen since we last examined him, which could affect his tolerance of the anaesthetic. You will be asked when he last ate and drank and exactly what. The reason for this is that if we have to anaesthetize dogs with a full stomach, this sometimes causes problems with breathing when relaxed under the anaesthetic. Starving for 12 hours before an anaesthetic was at one-time routine to prevent vomiting. Modern anaesthetic agents are less likely to cause sickness.
You will also be offered to do a pre-anaesthetic blood test to ensure that there is no contraindication to administer anaesthesia. Please be aware there is always a small risk involved with anaesthesia, the same as in humans.
What happens next?
As part of the pre-anaesthetic examination, a premedicant will be administered. Today this is usually a sedative and an analgesic. This combination ensures that your dog will not worry and will be relaxed and laid back although still awake and aware of his surroundings.
The analgesic is administered so that when he wakes up after the anaesthetic he will not be feeling any pain or discomfort from the surgery.
What sort of anaesthetic will you give my dog?
Today there are many different types of anaesthetic agents. After the premedicant has had time to work, general anaesthesia will be induced and this usually involves an intravenous injection which is administered slowly usually into one of the veins of the front legs although occasionally a rear limb or the jugular vein in the neck will be used.
Once consciousness is lost the dog is laid on his side and an endotracheal tube is placed into his windpipe through the larynx. This is then connected via tubing to an anaesthetic machine and maintenance of anaesthesia begins. Usually, for this, a gaseous anaesthetic is used together with oxygen. This ensures that while unconscious sufficient oxygen reaches the brain and tissues and at the same time allows controlled amounts of the selected anaesthetic agent to be administered.
These agents have a much shorter action than any of the injectable drugs and therefore anaesthesia can be controlled very much more precisely. In some cases solely oxygen is delivered from the anaesthetic apparatus and the level of anaesthesia is controlled by drugs delivered via an intravenous line. The choice depends very much on the condition and type of surgery etc. We are more than happy to discuss these individual aspects with you.
My dog is very old, will he be able to stand all this?
Until very recently most anaesthetic agents had profound effects on heart and respiration. Today, there are anaesthetics available which have gone a long way to remove these risks, therefore they are suitable for animals considered previously to be extremely poor risks, e.g. very old animals or those with heart or chest problems.
Will my dog take very long to come round from the anaesthetic?
The aim of balanced anaesthesia today is to try to ensure that the patient is beginning to regain consciousness as he leaves the operating theatre. However, depending on the nature of the surgery, sedative agents may be administered to ensure that movement is kept to a minimum.