Our organization teaches hands only CPR according to the 2010 AHA guidelines that recommend that bystanders who witness a sudden collapse of an adult should activate the emergency medical services and provide high-quality chest compressions by pushing hard and fast in the middle of the victim’s chest, with minimal interruptions.
Cardiopulmonary resuscitation (CPR) has been used for 50 years. Traditionally, CPR involved chest compressions and rescue ventilations. Why the change in 2010? First the science. A number of animal studies have been performed and showed that the addition of rescue ventilations did not improve outcome compared with compressions alone. Several randomized trials in humans have been performed which show compressions only CPR lead to better outcomes versus traditional CPR with rescue ventilations. A large trial out of Japan showed a favorable neurologic survival of 41% at one month versus 33% with conventional CPR in witnessed cardiac arrest victims with ventricular fibrillation as the presenting rhythm. This should be the survival goal after out of hospital cardiac arrest (OHCA).
There are many reasons why compressions only CPR might more effective. First, rescue breathing increases intrathoracic pressure and this reduces cardiac venous return to the right ventricle. Rescue breathing can be difficult and often interrupts chest compressions. It is critical to minimize the interruption of compressions with a goal of less than 10 seconds on CPR provider exchanges.
This is a graph recorded from a catheter in the aorta during a pulseless electrical activity (PEA) arrest. The heart rhythm is recorded on the 2 upper lines. The pressure waveform is on the bottom with a mean pressure tracing also recorded. This shows 2 important findings. First, there is a brief break in CPR as CPR providers change. In that time, the mean arterial pressure plummets to 20 mm Hg. Second, even though it appears that the CPR is adequate, with the fresh CPR provider the mean arterial pressure is increased by 15 mm Hg. This is why changing CPR providers every 90-120 seconds is optimal if possible.
Teaching hands only CPR (compression only CPR) is relatively easy and quick to learn. Studies have shown a sustained improvement in learning, remembering and performing hands only CPR. Compared with conventional CPR, hands only CPR has been shown to lead to faster times to initiating resuscitation efforts. Because of the ease of learning of hands only CPR, it is hoped that this will reduce barriers to bystander action.
When a person collapses with a cardiac arrest most likely the arterial oxygen saturation level in their blood will be greater than 90%. The cardiac arrest victim should have enough oxygen in their blood for the next 6-8 minutes. CPR should concentrate on circulating the blood through adequate compressions, rate of 100-120 compressions per minute at a depth of compression of 2 inches on the chest. However, it is critical to activate emergency medical services (EMS) so that they can provide more advanced care upon arrival.
During compressions of the chest there is movement of air in and out of the lungs. The level of oxygen in the environment is 21% and the amount in exhaled breath is 16%. Until the oxygen level in the blood gets very low it will be hard to raise the oxygen level with bystander rescue breathing. Often during a cardiac arrest, bystanders are hesitant to act due to a risk of infection or contact with the victims mouth. Hands only alleviates this concern and simplifies the process of resuscitation.
In summary, the science and physiology supports compression only CPR. Furthermore, it is easier to teach, learn, remember and perform than conventional CPR. It is critical to activate EMS and get the expert help on the way. Push hard and fast in the center of the victim’s chest and don’t stop until help of an AED arrives.
Iwami T, et al. Chest compression-only cardiopulmonary resuscitation for out-of hospital cardiac arrest with public access defibrillation. Circ. 2012;126:2844-2851.
Sayre M, et al. Hands-only (Compression-only) cardiopulmonary resuscitation: A call to action for bystander response to adults who experience out-of-hospital sudden cardiac arrest Cir. 2008;117:2162-2167.