Information

Pre-anaesthetic Blood Testing

Pre-anaesthetic blood testing is done to increase safety when your pet is to go under a general anaesthetic.

Anaesthesia involves injection or inhalation of medications that will place your pet in a reversible state of unconsciousness to allow us to perform surgery or diagnostic procedures.

Anaesthesia carries a certain level of unavoidable risk, but these risks can be mitigated by careful patient work-up and careful selection of the most appropriate anaesthetic agents and techniques.

Part of this work-up involves Pre-Anaesthetic Blood Testing.

Blood testing allows us more information on the health of your pet. It allows us to detect conditions or diseases that may be undetectable through superficial clinical examination. These include:

• Abnormal kidney function
• Abnormal liver function
• Abnormalities in protein levels
• Abnormal blood glucose
• Abnormal electrolyte salt levels

Some injected anaesthetic medications travel in the blood bound to circulating proteins. The liver is often responsible for processing the medication and the kidneys often play a role in eliminating it from the body. The electrolyte balance of the body can indicate the health of various body systems and can also influence the action of anaesthetic drugs within the body.

Clearly it is important that all these factors are within normal limits and that the liver and kidneys are operating properly. Pre-Anesthetic blood testing checks that this is the case. If there are pre-existing problems, and blood tests are not done, then a standard dose of anaesthetic has potential to have disastrous consequences.

As well as reducing anaesthetic risk, blood testing also confirms that it is ‘worth’ undertaking an anaesthetic in the first place. An example of this is elderly cat dental work. If the blood tests expose an underlying kidney problem then it can be unsafe and a waste of money to commit to dental work until the cause of the kidney problem can be determined and treated.

We have equipment to do blood tests in-house on the day of anaesthesia.

A small amount of blood is collected and biochemistry tests run to ensure each patient is safe and stable for anaesthesia and that we can make the best and safest choices of medication and technique.

Pre-anaesthetic blood testing is mandatory in patients beyond 8-9 years of age as we consider these senior patients to be at highest risk. It is advisable to do blood tests before anaesthetising patients of any age as we sometimes find serious problems even in younger patients. Sometimes certain aspects of a patients health and their presenting complaint might make blood testing advisable. In each case we will discuss options with you.