Veterinary Anesthesia: Best Practices on the Anesthetic Front

Medical articles

Unless you’re made of stone, you’ve experienced the anxiety associated with dropping off your pet for an anesthetic procedure. Even veterinarians are not immune.

To be sure, some of us well understand that these are largely irrational thoughts. And yet the horror stories we’re often treated to in the media and among friends and family would have us believe that anesthetic procedures in pets are necessarily fraught with significant degree of peril.

But I’m here to tell you that in animal hospitals where best practices are employed –– indeed, across the board –– adverse anesthetic events (the official term for any scary reaction under anesthesia, not just death) are far from prevalent. Consider the following statement from an article in Firstline, a veterinary publication targeting veterinary technicians:

“Anesthesia safety has vastly improved over the years, but pets still face a risk when they're anesthetized. In North and South America, the risk of anesthetic-related death in dogs is about 0.1 percent, according to an article in the Oct. 1, 2008, issue of the Journal of the American Veterinary Medical Association. This is a low number, but it's still higher than the 0.02 percent to 0.05 percent risk of anesthetic-related death humans face.”

The reason for this sizable discrepancy between human and animal medicine is multifactorial. But I break it down to three main reasons:

  • We have fewer board-certified anesthesiologists in our profession. By 2009, there were still less than 200 of these specialists in the US. Which means very little research is being undertaken to determine how we can mitigate these events.

  • The research we do have is largely based on the human medical profession’s findings. And humans, as you might imagine, aren’t always good models for animals when it comes to anesthesia.

  • The final reason has more to do with cost concerns and best practices in animal hospitals across the country. Not every hospital has access to the highly trained personnel and expensive equipment it takes to minimize adverse anesthetic events.

Yet there are still steps we can take to minimize them:

#1 Physical examination

We veterinarians screen our patients to ensure they’re healthy, taking into consideration that non-routine procedures on less robust patients must be moderated to their specific challenges. Physical examination is the most basic (and, in many ways, the most important) method of screening patients.

#2 Basic labwork

CBCs, chemistry panels and urinalyses, in particular, provide the foundation for assessing our patients’ degree of risk. Here we’re trying to assess a pet’s hydration status, electrolyte balance, basic liver and kidney function, red and white blood cell counts, platelet levels, parasite and infectious disease status, etc. so that these can be addressed before administering drugs that might challenge a pet suffering any deficiencies in this area.

Any significant findings in the above two screening approaches may find us refusing to anesthetize a pet. It’s up to additional testing to better determine the real risks involved. Advanced labwork, X-rays, ultrasounds and EKGs, or full cardiac workups are common follow-ups. CT scans, specialist consults, and MRIs may also play a role for the luckier, well-heeled pets whose owners can afford to spring for investigation into specific problem areas in advance of the procedure.

#3 Highly trained support personnel

It’s not enough for the veterinarians to know what’s happening during an anesthetic procedure. Trained technicians –– preferably certified technicians –– who know how to assess a patient’s status effectively and use the tools of the trade are essential. I cannot underscore this enough.

#4 Intravenous catheterization

No, not every vet will require every patient to sport an IV catheter throughout a procedure. But you should know that it’s always safest. In fact, it’s one of the easiest ways to make your pet safer during any given procedure, no matter how routine. If you have the extra $15-$30 to spend, you’ll definitely want to request one.

#5 Intravenous fluid administration

Fluids can make a huge difference to many pets—especially during longer procedures or when using drugs that may cause drops in blood pressure (a great many of the drugs we use for anesthesia). Again, this is always safest. But there are a few exceptions, the most notable of which includes a variety of cardiac conditions.

#6 Warmth and temperature monitoring

Some of our anesthetic monitoring equipment comes supplied with a rectal probe to continuously monitor our patients’ temperature. I’m a big fan of this feature. It’s easy to ignore temperature changes. And drops in temperature during anesthesia can be precipitous. Hot air/hot water pads (or simple, low-tech hot water bottles) can be invaluable, especially for our smaller patients whose temp drops are most likely.

#7 Heart rate monitoring

This bit of equipment is usually built into the same monitor that reads the oxygen concentration. It beeps reassuringly throughout the procedure while registering the number of beats per minute on a screen.

#8 Pulse oximetry and carbon dioxide level monitoring

Pulse oximetry is a fundamental tool, one for which no procedure is too routine to dispense with. This simple device, a blood oxygen monitor, is applied to an extremity or tongue to measure the percentage of blood, a value which appears on the monitor’s screen.

#9 Continuous EKG monitoring

This is another basic tool which may or may not be part of the pulse oximeter and heart rate monitoring equipment. And it’s simple. Just clip the lines onto a pet and watch the screen. It, too, records the heart rate and any vet can see at a glance when scary electronic changes are happening to the heart. This makes it much easier to tailor our drug administration in the event of a cardiac arrest.

#10 Blood pressure monitoring

Many hospitals also have this capacity built into the EKG and pulse oximetry system. It can be essential to know exactly where your BP is at during surgery, though it’s a shockingly underused tool in vet medicine relative to the human side of things.

#11 Judicious, individualized drug usage

Though you can easily request all of the above from the average veterinary facility (note: you may not get them all, depending on the level of care you can afford), the choice of anesthetic drugs is a far more individual –– and personal –– endeavor.

That’s because most of us stick to drugs we’re comfortable using. We’re familiar with the kinds of reactions and complications we see most often with the cocktails we’re familiar with. So, when you ask us to use a drug we’re not experienced or comfortable with, the risks can climb—not exactly the goal you had in mind.

Nonetheless, the best veterinary anesthesiologists will tell you that drug choices should always be tailored to the individual patient. And most progressive veterinarians practice according to these principles.

Note: Individual pet history is a far more critical factor here than most breed-specific warnings (many of which are way overblown if downright untrue).

Ideally, you’ll trust your veterinarian on this. If you have profound reservations about certain drugs, however, you’ll want to find a veterinarian who does not use them or can easily shift course to another protocol that he/she deems perfectly acceptable in their stead.

#12 Veterinary experience

Again, here’s another area where you’ll just have to be comfortable with your vet’s level of experience. Presumably, you’re not even considering an anesthetic procedure at a practice whose veterinarians seem to lack the kind of experience and/or training you deem acceptable for your pets, right?

But don’t assume that more years in practice equals greater competence in a crisis. Sometimes it’s the younger vets with a healthier dose of fear at the ready who make for the best practitioners in the case of an adverse anesthetic event.