For most adults who collapse from cardiac arrest, CPR does not require mouth-to-mouth. The American Heart Association recommends “hands-only” CPR for bystanders witnessing an adult collapse: call 911, then push hard and fast in the center of the chest. No breathing into the person’s mouth is needed. There are important exceptions, though, particularly for children, infants, and drowning victims.
Why Mouth-to-Mouth Is No Longer Standard for Adults
When an adult’s heart suddenly stops, their blood still contains several minutes’ worth of oxygen. The priority is keeping that oxygenated blood moving to the brain and vital organs, which chest compressions accomplish on their own. Pausing compressions to deliver rescue breaths interrupts blood flow during the moments it matters most.
The survival numbers back this up. A nationwide study published in Circulation found that 30-day survival for out-of-hospital cardiac arrest was 13.5% with compression-only CPR and 13.8% with traditional CPR that included rescue breaths. Both were dramatically better than the 5.8% survival rate when no CPR was performed at all. The takeaway: for a typical adult cardiac arrest, compressions alone are nearly as effective as the full technique, and far better than doing nothing.
Fear of mouth-to-mouth contact has long kept bystanders from stepping in. Survey data found that only 15% of people would “definitely” perform CPR with rescue breaths on a stranger, compared to 68% who would “definitely” do chest compressions alone. Even with friends and family, willingness jumped from 74% to 88% when mouth-to-mouth was removed from the equation. Hands-only CPR eliminates that barrier completely.
How to Perform Hands-Only CPR
The technique is straightforward. Place the heel of one hand in the center of the person’s chest, put your other hand on top, and push straight down at least 2 inches but no more than 2.4 inches. Push at a rate of 100 to 120 compressions per minute, which is roughly the tempo of the song “Stayin’ Alive.” Let the chest fully rise between each compression, and don’t stop until emergency medical services arrive or an AED becomes available.
If you call 911, the dispatcher will typically walk you through these steps in real time. About 83% of 911 call centers use a structured script for giving CPR instructions over the phone. AHA guidelines specifically recommend that dispatchers give “straightforward chest compression-only instructions” for adults who suddenly collapse. You don’t need prior training to follow along.
When Rescue Breaths Still Matter
Hands-only CPR works well for adults whose hearts stop due to a cardiac problem, because the issue is circulation, not oxygen supply. But several situations are different because the person’s core problem is that they’ve stopped breathing, and their blood oxygen has already dropped dangerously low. In these cases, compressions alone aren’t enough.
Drowning
Updated AHA guidelines released in 2024 state that all people pulled from the water with no signs of normal breathing or consciousness should receive CPR with rescue breaths and chest compressions. Cardiac arrest from drowning is caused by severe oxygen depletion, not a heart rhythm problem. Research shows drowning victims are more likely to survive when CPR includes rescue breaths. Trained rescuers should start with two rescue breaths, then alternate 30 compressions with 2 breaths.
Infants and Children
Children and infants are more likely to experience cardiac arrest from breathing problems (choking, respiratory infections, suffocation) rather than from heart conditions. Rescue breaths are a critical part of pediatric CPR. The standard ratio is 30 compressions to 2 breaths for a single rescuer. With two rescuers, the ratio shifts to 15 compressions and 2 breaths. If the child has a pulse but isn’t breathing, rescue breathing alone at a rate of about 20 to 30 breaths per minute is recommended.
Drug Overdose and Choking
Opioid overdoses and choking incidents cause the person to stop breathing before the heart stops. Like drowning, the underlying problem is oxygen deprivation. Rescue breaths help restore oxygen levels that compressions alone can’t address. If you’re trained in conventional CPR, use it in these situations.
What If You’re Not Trained in Rescue Breaths?
Even in drowning, choking, or pediatric emergencies, compression-only CPR is better than no CPR. If you don’t know how to give rescue breaths or aren’t comfortable doing so, start chest compressions immediately and keep going. The worst outcome is hesitating and doing nothing. The 911 dispatcher can guide you through whatever technique is appropriate for the situation while help is on the way.
Using an AED Alongside Compressions
An automated external defibrillator (AED) pairs naturally with hands-only CPR. If someone nearby can grab an AED while you’re doing compressions, it can analyze the person’s heart rhythm and deliver a shock if needed. The device gives voice prompts, so no training is required. Resume compressions immediately after the shock. The combination of early compressions plus early defibrillation gives someone in cardiac arrest the best chance of survival.
AEDs are increasingly common in airports, gyms, schools, and office buildings. Knowing their location ahead of time can save critical minutes. Every minute without CPR or defibrillation reduces the chance of survival by roughly 7% to 10%.