One of the more apprehensive events for a pet owner to experience is for their dog or cat to undergo an anesthetic procedure. In fact, these procedures are now often more stressful for the average pet owner to experience than for their dog or cat. At the same time One certainly can understand their anxiety. Some of you who are long time pet owners may have experienced or heard of someone who has had a cat or dog die during an anesthetic procedure. Fortunately the veterinary profession has grown dramatically over the past 20 – 25 years to increase the safety of anesthesia for pets.
Tremendous steps that have been taken to improve all aspects of anesthetic and surgical procedures for our patients. To appreciate these changes, it is important to understand the stages of an anesthetic procedure. Patient preparation begins with a thorough history from the pet owner regarding any medical problems they may be noticing in their dog or cat. The veterinarian should then perform a complete physical examination. Our clients can trust us with the lives of their pets and no shortcuts will be taken.
All anesthetic patients have a pre-anesthetic blood panel performed to screen for any underlying problems, such as kidney or liver disease. These conditions may not be evident in the history or examination, but may certainly affect how a patient performs under anesthesia. In numerous cases we have discovered serious abnormalities on pre-anesthetic blood profiles that were not detectable in the examination. Dogs, and especially cats, are very good at hiding an illness, often until they are very sick. Pre-anesthetic blood panels decrease this risk.
If the history, physical examination and blood profile are all within normal, the patient is then given a pre-anesthetic sedative and analgesic (pain reliever). I feel very strongly that for any procedure that has even the slightest chance of causing a patient pain, analgesics should be given prior to the surgery. It has been proven that pre-emptive analgesia not only decreases pain, but also decreases the need later for higher post-operative doses of the analgesic, as well as anesthetic induction medications, thus increasing the safety of the procedure. Over the past decade the veterinary profession has significantly improved it’s understanding of pain relief for dogs and cats, which in turn has greatly improved the recovery time for our patients after surgery.
After the pre-anesthetic medications are administered, an intravenous catheter is placed in one of the front or back legs. Induction anesthetic drugs are usually administered through this catheter, causing the animal to completely fall asleep. Newer and significantly safer anesthetic drugs are now available that are ultra-short acting or even reversible, allowing patients to be up and walking within minutes of being anesthetized. Intravenous fluids are also administered while the patient is under anesthesia to prevent dehydration and help maintain blood pressure. This catheter also serves as a portal for emergency medications in the event of an anesthetic crisis. For most procedures a patient is then intubated through its mouth with an endotracheal tube after being given an induction agent. Oxygen and inhalation anesthetics are given through this tube into the lungs, allowing the patient to be maintained under anesthesia for the duration of the procedure. Inhalation anesthetics currently used are very short acting, allowing us to more precisely control the depth of anesthesia for a patient.
One of the greatest areas of advancement is that of patient monitoring. Instruments now available allow us to monitor a dog or cat’s heart rate, respiratory rate, oxygen saturation, carbon dioxide level, temperature and blood pressure. If any one of these values start to approach an abnormal level, we are aware of it usually before it causes a problem, and able to take necessary steps to correct it. These values are monitored until the patient is awake and sitting up or standing.
Due to the increased safety of anesthetic procedures, the age of a cat or dog is much less of a concern. With the drugs and instruments now available to the veterinary profession a 15 year-old-cat may be just as good of an anesthetic candidate as a kitten. Though old age in a cat or dog has added health issues, it is not a reason by itself to avoid anesthetic procedures.
Anesthesia is never risk free, but in most situations the benefits of the procedure greatly outweigh the risks. With proper preparation, pre-anesthetic screening, drug selection and anesthetic monitoring, these risks are greatly reduced.