Protocols for General Anesthetic

Anesthesia and patient monitoring varies greatly among clinics!
When you choose your veterinarian, be sure to question the types of anesthetics used and the protocols for monitoring anesthesia.

Often, the more expensive anesthetics are safer to use; however, anesthetics are also chosen for other reasons including their ability to control pain.

Your pet’s safety under general anesthetic is very important to us!

We have developed the following protocols to minimize the risk associated with general anesthetic

Before Anesthesia:

1.)  Bloodwork prior to surgery.  This is a vital precaution in reducing the risks of anesthesia. It provides us with information about how your pet’s internal organs and blood cells are functioning. It can help us pick up early signs of disease that may not be detectable on a complete physical examination.

2.)  Thorough physical examination on the day of surgery.  A complete physical exam is performed on the morning of surgery by a veterinarian to ensure your pet is not affected by any illness that would increase their risk during anesthesia.

During Anesthesia:

1.)  IV fluid therapy.  Blood pressure tends to drop during anesthesia and if it drops too low it can cause damage to your pet’s internal organs. Intravenous fluids are used to maintain blood pressure to prevent this damage. As well, administering IV fluids allows us access to provide drugs rapidly in case of an emergency situation. We find pets on IV fluids tend to wake up from anesthesia faster and with fewer complications. We also use an IV line warmer (shown) to help maintain a normal body temperature during general anesthesia.


2.)  Isoflurane gas for maintenance of anesthesia.  There are multiple types of inhalant gas available to be used for maintenance during anesthesia. Halothane, used to be widely used for this purpose, but has fallen out of favour due to newer, safer anesthetics. Our clinic uses the newer isoflurane, as it is one of the safest available.



Hot water pad, thermometer and oat bags.

IV Line Warmer

3.)  Thermoregulation.  To help maintain your pet’s normal body temperature under anesthesia, they will be kept warm on a circulating hot water pad. Extra warmth is provided by either heated oat bags placed near your pet’s body or a Bair Hugger (this is a machine that surrounds your pets body with warm air).  We also use an IV line warmer to ensure that the IV fluids are the same as your pet’s body temperature, since this is warmer than room temperature).  We have a thermometer to measure core body temperature continuously during general anesthesia.

4.)  Apnea alert.  This machine is attached to the end of the endotracheal tube where we deliver oxygen and gas anesthetic, and alerts us every time your pet takes a breath. When several seconds have gone by without a breath taken, an alarm will sound.


5.)  Blood pressure, heart rate, heart waves, respirations, exhaled carbon dioxide, temperauture and oxygen saturation of the blood. All of the above parameters are measured continually using the Cardell monitoring device (pictured). Continual monitoring allows us to detect any problems early so they can be treated appropriately.  We will also attach another blood pressure monitor called a Doppler.  The Doppler’s probe is placed on the skin directly in contact with a small artery on your pet’s foot and converts each pulsation from the heart into a sound.  This way we can directly listen to your pet’s heart rate and rhythm during the entire anesthetic.

Blood pressure – Monitoring blood pressure is very important because a decrease in blood pressure can be a side effect of anesthetic drugs. Increased periods of low blood pressure can lead to irreversible damage to vital organs such as the liver, kidneys and brain. If we detect a decreased blood pressure in your pet during surgery we can correct it by decreasing the amount of gas anesthetic or increasing their IV fluid rate.

Heart Waves (ECG) – This allows us to detect abnormal rhythms immediately so they can be treated appropriately.

Exhaled Carbon Dioxide – This allows us to determine how well your pet is brething under anesthesia. Hypoventilation can occur in an animal under anesthesia, which if left untreated can lead to cardiac arrest. We use a side-stream monitor, which is especially good for small patients.

Oxygen Saturation of the Blood – A non-invasive pulse oximeter measures the amount of oxygen in your pet’s blood during anesthesia. This allows us to make sure your pet is receiving enough oxygen during surgery.

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