A vital component of CPR is Rescue breathing, and may be part of your upcoming CPR certification or CPR course. Rescue breathing, however, can be daunting to some. Commonly known as “mouth-to-mouth resuscitation”, it has typically been part of every CPR class. It requires class participants to go mouth-to mouth on a victim of cardiac arrest, and breathe into their mouth while ensuring a clear airway. Most current guidelines recommend that rescuers perform two rescue breaths for every 30 corresponding compressions.