Chapter 1
Patient Evaluation
Prevention is the Best Medicine!
Lesley J. Smith
Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin, USA
- Q. Why is it important to perform a complete patient evaluation?
- A. Almost without exception, all anesthetic and analgesic drugs have potential toxic effects on organ systems. For example, the inhalant anesthetics significantly decrease blood pressure and organ perfusion such that an animal with pre-existing renal compromise may suffer irreversible renal damage if inhalants are used without monitoring and support of blood pressure. This damage may be even worse if nonsteroidal anti-inflammatory drugs (NSAIDs) are used prior to or during anesthesia.
A complete patient evaluation allows the veterinarian to identify potential health concerns and temperament issues that will affect how that animal responds to the various anesthetic drugs that may be used. In some cases, it may be important to avoid certain anesthetic or analgesic drugs because of identified health concerns. Often many, if not most, anesthetic drugs can be used in patients with significant health problems, but the dose of those drugs may need to be adjusted to minimize known side effects that may be harmful to that particular patient. To continue with the example provided above, in a patient with renal disease inhalants can still be used to maintain anesthesia, but the dose of those inhalants should be kept as low as possible to minimize their negative effects on blood pressure and renal perfusion. Keeping the inhalant dose very low can be achieved by adding other anesthetic or analgesic drugs to the anesthetic protocol, as will be covered in depth in later chapters.
- Q. Under what circumstances may patient evaluation be less than complete?
- A. Occasionally a patient may be simply too aggressive or unhandled to allow for any physical examination to be conducted safely. Some animals, for example birds, may undergo significant stress from excessive handling and will benefit from a more limited physical examination. Even under these circumstances, however, careful observation “from a distance” can provide important information such as body condition (obese, thin, or just right?), haircoat and general appearance of health, posture and gait (normal or abnormal?), respiratory pattern and effort.
- Q. What important questions should I ask the owner when taking a history?
- A. The owner may volunteer a lot of information in the history that is or isn’t relevant to anesthesia. Some questions that should be asked include:
- Has your pet had anesthesia previously and how was his/her recovery at home? – This may alert you to risks of prolonged effects of sedative or other drugs used in the anesthetic protocol.
- Are you aware of any problems that your pet had with anesthesia in the past? – Often owners will not know, or will be unsure of, which anesthetic drugs were used previously, but if they recall a specific event (e.g., the vet said he/she had a rough recovery) this can alert you to potential drugs to avoid or to use (e.g., perhaps the rough recovery was because the dog experienced emergence delirium, so this time a longer acting sedative may be indicated).
- Are you aware of any relatives of your pet that have experienced complications with anesthesia? – For example, herding breeds of dogs may experience prolonged and profound sedation from certain sedatives and opioids.
- Is your pet allergic to any foods or medications that you know of? – Clearly, known allergies to certain medications would indicate that those medications, or ones that are in the same class, should be avoided. Rarely, dogs will have an allergy to eggs, which would make propofol contra-indicated, as propofol contains egg lecithin.
- How is your pet’s general energy level? Does he/she tire easily or get out of breath quickly during exercise? – Exercise intolerance is a red flag to be on the lookout for cardiovascular or respiratory disease, anemia, or endocrine disease!
- Are there any recent changes in drinking or urination habits? – Increases in frequency of water intake should put you on the medical hunt for diseases that cause PU/PD, such as renal disease or diabetes.
- Has there been any weight loss or gain that you’ve noticed recently? – Again if these cannot be explained by a diet change or lifestyle change, then you should be on the hunt for underlying medical issues that could lead to weight gain or loss (e.g., thyroid disorders).
- What medications is your pet currently taking? What about nutraceuticals or herbal remedies? – Some medications can directly and significantly impact how the animal responds to anesthetics. For example, ACE inhibitors (e.g., enalapril) can lead to low blood pressure under anesthesia that is unresponsive to most normal interventions.
Stay updated, free articles. Join our Telegram channel
- Has your pet had anesthesia previously and how was his/her recovery at home? – This may alert you to risks of prolonged effects of sedative or other drugs used in the anesthetic protocol.
Full access? Get Clinical Tree
