The Nuts and Bolts of CPR
Dog owners should be aware that in no way is CPR a guarantee that a dog will start breathing again. “Papers have shown that the actual success rate of CPR is not great, which is the same as for people,” says Armelle de Laforcade, DVM, an emergency and critical care veterinarian at Tufts. “We can in many cases get the heart beating again, but the dog will have a high chance of arresting again or not leaving the hospital.”
In certain types of instances, however, CPR has a higher chance of success, and in those cases, Dr. de Laforcade says, “we try to be very aggressive.”
One of those instances is a dog who’s healthy and has an anesthetic complication during surgery. Many times, such dogs undergo CPR and end up “back home with their families,” Dr. de Laforcade notes. “We did a study at Tufts that showed that animals that die under anesthesia are more likely to leave the hospital after CPR than animals who get CPR for other reasons,” she points out. A dog who has a fit of vomiting and whose heart slows down because the vomiting affects vagal tone may also do fine with CPR. With chest compressions and some drugs, the animal starts breathing normally again. A little tear in the lung that causes air to leak out and breathing to become compromised, perhaps from a car accident, can also result in successful CPR because the dog’s other organs and systems are all fine.
Veterinary nurses (vet technicians, as they are called formally) can receive certification in CPR as well as veterinarians themselves. Part of the training is learning how to do effective chest compressions to get a return of circulation, that is, to promote blood flow to the brain and all other body systems. “People are more or less shaped the same,” Dr. de Laforcade says, “but with dogs, you have a 3-pound Chihuahua and a 200-pound mastiff. Getting blood to flow so that oxygen is delivered to the brain, the heart, and the lungs is going to be different for the two animals. If you have a small animal, it’s easier to physically compress the heart and cause the blood to move forward. The bigger the dog, the harder it is to compress the heart through the chest. It’s tricky.”
That’s what some of the training is about. “You have to give good-strength compressions and not go too fast,” Dr. de Laforcade says. “The heart needs time to fill between beats.”