Safe Anesthesia in Our Pets

By Dr. Ann Sosalla

To many people, the idea of anesthetizing the family pet is scary.   Many pet owners are concerned about the safety of anesthesia, especially in an older pet.   Will my pet survive?  What if there are complications?   How long will he be sleepy?  People are also concerned about the cost.    Modern drugs and medical equipment in veterinary medicine, just as in human medicine, are rising.  Understanding what safe anesthesia involves may help alleviate people's fears. 

Modern anesthesia can be very safe if administered correctly.  Yes, just as in human medicine, there is always a small risk involved.  However, the more things that are done to minimize the risk, the safer the anesthesia will be. 

Ideally, the patient to be anesthetized should be healthy.  Veterinarians cannot detect all health problems with a physical exam, so blood tests should be done to ensure the health of the internal organs.  These blood tests measure the glucose levels, liver enzymes, the kidney function, and the red blood cell numbers.  Older animals should have more extensive tests run, but younger animals often just have a "mini panel".  A healthy liver and kidneys allows the animal to properly metabolize (break down and excrete) the anesthetic drugs. 

Every pet undergoing anesthesia should have an intravenous catheter placed and intravenous (IV) fluids should be given.   The IV catheter can be thought of as a "life line".  If there is an adverse event during anesthesia, the IV allows instant administration of life saving medications.  The administration of fluids keeps the blood pressure at a safe level.

Every anesthetized pet should have an endotracheal (ET) tube placed and a modern safe anesthetic gas and oxygen administered.   The ET tube is a breathing tube placed through the mouth and into the trachea.   It delivers gas and oxygen to the lungs.  It also prevents accidental inhalation of stomach contents should the pet vomit or water and bacteria during a dental cleaning.  If the pet does not breathe well on its own, the ET tube allows the nurse to breath for the animal thus maintaining safe oxygen levels in the blood.   The modern anesthetic gasses (isoflurane and sevoflurane) are rapidly excreted from the body, resulting in rapid changes in depth of anesthesia if needed and quick recovery times.  Typically, the patient is awake within minutes of discontinuing the gas. 

Maintenance of all anesthetized pets should include a means to keep them warm.  Pets lose body heat during anesthesia.  Hypothermia can cause dangerously low blood pressure and slow recovery times.  Blankets that circulate warm water or air are the safest and most effective.   Heating pads and hot water bottles can cause burns.

Persistent monitoring of anesthetized pets also ensures their safety.  Measuring and recording their "vitals"  such as temperature, respiratory rate, heart rate, blood pressure, oxygen saturation, and depth of anesthesia should be done by someone other than the surgeon, preferably a Certified Veterinary Technician.   Accurate monitoring allows early recognition of trends so that changes can be made if necessary. 

Pain management (analgesia) is extremely vital for safe anesthesia.   Not only does it keep our pets comfortable, more importantly, proper analgesia allows veterinarians to use much LESS anesthesia.  Adequate pain control includes pre-emptive analgesia (blocking the pain pathways before the painful stimulus) and multimodal analgesia (blocking the pain pathways from several directions). 

The price of anesthesia may very from clinic to clinic depending on the protocols used.  Modern safe anesthesia and analgesia requires the veterinary clinic have a lot of equipment and expertise, and this unfortunately costs money.  Cutting corners, such as eliminating monitoring or warming equipment, not intubating and placing an IV catheter, inadequate pain management, and not adequately training the healthcare team can save money.   The cost, however, is decreased comfort and increased risk to your pet.