If you read last week’s post, you know that performing cardiopulmonary resuscitation (CPR) on pets is often unsuccessful, as seen with Echo. If this veterinary specialist can’t revive her own cat at home (granted, I didn’t have my crash cart and emergency drugs at hand), it’s pretty unlikely a pet owner would be able to, especially without appropriate training. So, in Echo’s memory, I wanted to talk about cardiopulmonary cerebral resuscitation, now called CPCR, and how to adequately perform it on pets.
 

Unfortunately, CPCR is not like what you see on TV shows such as ER or Grey’s Anatomy. In these TV shows, people spring back from death, and are back to eating and talking within a few minutes. In veterinary medicine, the likelihood of getting an animal back with CPCR once their heart has stopped (i.e., cardiac arrest) or they have stopped breathing (i.e., respiratory arrest) is much lower compared to human medicine, averaging approximately 4 to 10 percent in dogs and cats.  In other words, 96 percent of dogs that go into cardiopulmonary arrest and undergo CPCR don’t survive at the hospital, while in cats it’s 90 percent.

The reason why the success rate of CPCR in veterinary medicine is so low, as compared to human medicine, is multifactorial: species differences, advances in human medicine, and causes for why the cardiopulmonary arrest occurred in the first place.

Humans typically go into cardiac arrest due to heart attacks (i.e., ventricular fibrillation) and can be defibrillated to stop the arrhythmia. That’s why you see so many automated external defibrillators (AEDs) around the airport. Pets, on the other hand, rarely have heart attacks due to ventricular fibrillation (which explains why there are no AEDs in dog parks), unless they have primary heart disease (like my cat Echo).

Remember that famous YouTube video where Ron Pace, a dog trainer, performed CPR on a Boxer while the pet owner looked on? The veterinarian in me ventures that the dog likely had ventricular fibrillation from arrhythmiogenic right ventricular cardiomyopathy (previously renamed from "Boxer cardiomyopathy"), and that’s why he was able to be resuscitated. The majority of the time, pets undergo cardiopulmonary arrest secondary to other types of arrhythmias (e.g., asystole, pulseless electrical activity, etc.), often due to advanced disease such as kidney failure, liver disease, cancer, or other underlying problems. As such, once a pet dies, it’s unlikely that veterinarians will be able to revive it and even more unlikely that it won’t happen again (75 percent of pets that cardiopulmonary arrest typically re-arrest within 24 hours, and again, that’s typically because of their severe, underlying disease).

When it comes to CPCR, we’re basically trying to support the ABCs of emergency medicine:

• Airway
• Breathing
• Circulation

We want to make sure the pet has a patent (open) airway where they can take in oxygen. For example, is there a tennis ball lodged in their airway, preventing them from being able to take in oxygen? Next, we want to make sure they are breathing adequately to take in that oxygen and blow out the carbon dioxide. By looking to see if the rib cage is moving, we can determine if our pet is taking adequate breaths or not. Finally, we want to make sure their heart is beating, which helps push blood throughout the body, thereby providing circulation. By putting both hands on the side of the chest (just behind the elbow), we can attempt to feel for a heartbeat. If no heart beat is felt, the chest compressions should be performed.

A few years ago, I worked with Diana to write up a "how to perform CPR on dogs." JP even modeled for us for a few of the pictures. (Ed. Note: petMD also has a resource on how to perform CPR on dogs).

Most importantly, know that CPCR is often unsuccessful, no matter how hard you try. Instead, I preach on prevention instead. If you notice severe signs in your pets, bring them to a veterinarian sooner rather than later. If you get them to a veterinarian earlier, life-saving therapy like oxygen, intravenous fluids, electrolyte supplementation, etc. can be initiated sooner, hopefully negating the need for doing CPCR in the first place.

Dr. Justine Lee

_{Pic of the day: Dog Trainer Saves Dog with CPR via YouTube}