What is chest recoil, and why is it so important?

Cardiopulmonary resuscitation (CPR) is one of the most fundamental skills for any EMS provider to know and perform well. It is the crux of emergency medicine, and is a truly straightforward physiologic principle: pump for the heart when it fails to do so for itself.

     The rules of CPR are simple: pump hard and fast. The recommended rate of compressions is 100-120 beats/min, and the recommended depth when doing compressions on an adult is one third the depth of the chest. By doing this, the provider performing compressions is able to continuously move blood throughout the body by forcibly pushing blood out of the heart. However, equally as important as adequate rate and depth of compressions is complete chest recoil. But what is chest recoil? This is the concept of taking all of one’s weight off of the chest between each compression to allow the chest to fully expand, which creates a negative pressure that draws blood back into the heart.¹ Drawing blood back into the heart is the only way tissue perfusion is actually able to occur. Tissue perfusion is the process of delivering blood - and, as a result, oxygen - to the vital tissues and organs of the body. 

     Many studies have been done to test the concept that incomplete chest recoil leads to negative outcomes for patients. In these studies, coronary and cerebral perfusion pressures, as well as mean arterial pressure and myocardial blood flow are examined when incomplete chest recoil replaces complete chest recoil. The results are consistent in demonstrating that blood flow and perfusion pressures are negatively impacted in a statistically significant way even when 10-20% of one’s body weight is “leaned” into the patient during the recoil phase of a compression,² or when the chest is only allowed to recoil to 75% of its full expansion.³ Having diminished perfusion to the brain and heart can quickly deprive these tissues of oxygen, effectively killing them, rendering your resuscitation attempt ineffective. Therefore, understanding the proper mechanics of chest compressions becomes the single most important aspect of running an effective cardiac arrest incident. 

How do we ensure full chest recoil?

Because of the delicate nature of cardiac arrest, it is important that we are educated and skilled in performing compressions of the appropriate rate and depth as well as with complete recoil for 100% of the compressions. In order to do this, regular training and practice are critical. Currently, there are devices on the market that can be used both in training and in real-life instances that are able to measure and record compression effectiveness, which includes adequacy of recoil. These devices can train and monitor providers which helps to control one aspect of an otherwise potentially hectic scene. 

     Keeping up on all EMS skills is vital to all providers, especially such fundamental ones. Therefore, be sure that you and your fellow volunteers or colleagues are maintaining your skills in order to provide the best treatment possible to each and every one of your patients. It can absolutely be the difference between life and death. 

1. Ryan, D. Emphasizing Full Recoil in CPR Instruction is Essential to Saving Lives. In Pulse CPR Website. Available at: https://inpulsecpr.com/full-recoil-cpr-essential-saving-lives.html. Accessed February 17, 2019. 
2. Zeurcher, M., Hilwig, R., Ranger-Moore, J., et. al. Leaning During Chest Compressions Impairs Cardiac Output and Left Ventricular Myocardial Blood Flow in Piglet Cardiac Arrest. NCBI Website. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3321356/. Accessed February 17, 2019. 
3. Yannopoulos, D.,  McKnite, S., Aufderheide, T. et. al. Effects of Incomplete Chest Wall Decompression During Cardiopulmonary Resuscitation on Coronary and Cerebral Perfusion Pressures in a Porcine Model of Cardiac Arrest. Science Direct Website. Available at: https://www.sciencedirect.com/science/article/abs/pii/S0300957204004149. Accessed February 17, 2019.