Prior to 2012, veterinary medicine had no consensus guidelines for veterinary CPR procedures. In addition, less than 6% of animals survived cardiopulmonary arrest to discharge, whereas human survival was 20%. The Reassessment Campaign on Veterinary Resuscitation (RECOVER) initiative involved over 100 board-certified veterinary specialists who developed evidence-based guidelines in hopes of improving the application, training, and ultimately survival-to-discharge in veterinary patients. This blog will address the most clinically-relevant guidelines, leaving the plethora of information behind the guideline to the reader to investigate on their own. The guidelines are available for free on the VECCS website.
How do we recognize a patient in cardiopulmonary arrest?
Rapidly assess whether the patient is unresponsive and is apneic (not breathing). If so, basic life support can proceed.
What is the best procedure for basic life support?
After rapid identification of an unresponsive and apneic patient, a rapid assessment of heartbeat and the presence or absence of palpable pulses should be performed. It’s unlikely that performing chest compressions for a short time at the onset of CPR will harm a patient that has a heartbeat so rescuers should not spend a long time looking for these. If absent heartbeat and pulses, chest compressions should be started immediately at 100-120 compressions per minute. These should be performed (typically) in lateral recumbency and the chest compressed by 1/3 to 1/2 the width of the thorax. Dogs and cats that are < 10 kg should be compressed directly over the cardiac apex (cardiac pump theory). Larger patients (> 10 kg) should be compressed over the widest portion of the thorax (thoracic pump theory). Recoil of the compression should be equally as important as the compression. Lateral intubation should occur to minimize any interruption of compression technique. After intubation, the ET tube should be tied in and the cuff inflated. A ventilation rate of approximately 10 breaths per minute with a tidal volume of about 10mL/kg and an inspiratory time of 1 second are recommended. This continues for a full two-minute cycle before advanced life support is initiated.
How often should the person doing chest compressions change to maximize efforts?
A switch every two minutes is recommended to be maximally effective.
After a full two-minute cycle of basic life support, what do you do then?
Advanced life support involves identification of cardiac arrhythmias, drug administration, defibrillation, and other interventions. After a two-minute cycle of CPR, if an ECG is available, the rescuers can pause, assess the cardiac rhythm on the ECG monitor, and then resume chest compressions and manual ventilation. The treatment of any cardiac arrhythmia can then be decided while another cycle of BLS is occurring.
How do you know if you are doing “good” CPR?
End-tidal capnography will indicate if appropriate compression and ventilation technique is occurring and, therefore, creating gas exchange. Rescuers should target >15 mmHg in dogs and >20 mmHg in cats to increase the chance of return of spontaneous circulation (ROSC).
What arrhythmias typically occur in CPR?
In veterinary patients, asystole, pulseless electrical activity (PEA), and ventricular fibrillation are the three most commonly-identified arrhythmias, with asystole being the most common.
If asystole is identified, what do you do?
When asystole and/or PEA are identified, the rescuers may administer epinephrine and/or vasopressin every other cycle of CPR. So an initial approach could be to administer epinephrine and/or vasopressin, then perform a round of BLS, reassess the rhythm, and if the patient is still in asystole perform another round of BLS, reassess the rhythm, and then administer another dose of vasopressor medications at that time. Low-dose epinephrine should be used for the first 10 minutes of CPR. After 10 minutes of CPR, high-dose epinephrine may then be used. Atropine should still be considered despite the lack of published scientific evidence in veterinary medicine.
What is the best way to give drugs during CPR?
Several routes of drug administration are possible during CPR such as intravenous (IV), intratracheal (IT), and intraosseous (IO). IV and IO routes are preferred over IT due to rapid delivery into the circulatory system, but IT may be used in patients where IV or IO access is unavailable.
Do you administer IV fluids routinely in CPR?
There was no specific recommendation made in the RECOVER guidelines, but human guidelines recommend administering IV fluids only if the arrest was hypovolemic and that patients with euvolemic or hypervolemic arrest should not receive IV fluids.
If ventricular fibrillation is identified, what do you do?
Defibrillation is the appropriate treatment for ventricular fibrillation (v-fib). Once v-fib is identified, BLS should be continued and the defibrillator should be prepared and charged. Once it is ready, a shock should be administered and then basic life support continued for two minutes until an effect is assessed. If the initial shock does not achieve ROSC, defibrillation may be repeated. If v-fib is prolonged, amiodarone or lidocaine may be administered and epinephrine and/or vasopressin considered every other CPR cycle. The defibrillator dose may also be increased by 50% with each subsequent shock.
How long is a routine CPR procedure?
The answer depends on how long the veterinarian would like to continue CPR and the cause (if known) for the arrest, in conjunction with the owner’s wishes regarding continued CPR. If you count the initial cycle of BLS, then an ECG assessment, then an additional two cycles of CPR after a drug is administered, and you continue that, say, for three drug administrations you are at approximately 14-16 minutes of CPR. That seems reasonable, although that is entirely up to the veterinarian’s discretion. CPR can last as long as the veterinarian deems it appropriate to do so.
About the author
David Liss, MS, RVT, VTS (ECC, SAIM), CVPM has an incredibly rich and diverse background in the field of veterinary technology. A registered veterinary technician in California, David holds a Bachelor’s in Sociology and an Associate’s Degree in Veterinary Technology. He also holds double board-certifications as a veterinary technician specialist in emergency/critical care and small animal internal medicine and has a diverse background in emergency and critical care nursing in addition to being a certified veterinary practice manager (CVPM). He has been technician manager at two different twenty-four-hour referral/specialty facilities in the Los Angeles area, has contributed to numerous veterinary texts and was awarded the Veterinary Technician Educator of the Year award by Western Veterinary Conference. David also holds a Master’s in Biomedical Science. David currently directs the veterinary technology program at Platt College in Los Angeles, works as an ICU technician at VCA Veterinary Specialists of the Valley in Woodland Hills, CA, runs his own consulting business: Veterinary Training and Consulting, Inc., and lectures worldwide.