CPR Technique

Part of First Aid

When someone’s heart stops, you have about 4-6 minutes before brain damage begins. CPR is the only tool you have without modern medicine.

Understanding Cardiac Arrest

Cardiac arrest is not the same as a heart attack. A heart attack means blood flow to the heart muscle is blocked — the person is usually conscious and in pain. Cardiac arrest means the heart has stopped pumping entirely. The person collapses, stops breathing, and has no pulse. Without intervention, they die within minutes.

In a post-collapse world, cardiac arrest will most commonly result from:

• Drowning (river crossings, fishing accidents)
• Electrocution (improvised electrical systems)
• Severe allergic reactions (insect stings, unknown plant ingestion)
• Choking (see Choking Response)
• Hypothermia (cold water immersion, exposure)
• Trauma and blood loss leading to heart failure

CPR without a defibrillator has a low long-term success rate — roughly 5-10% in the best modern studies. But “low” is not “zero,” and for drowning and hypothermia victims, success rates are significantly higher. The person in front of you deserves the attempt.

Assessment: The 10-Second Check

Before starting CPR, you need to confirm cardiac arrest. This should take no more than 10 seconds.

Step 1 — Ensure scene safety. Do not become a second victim. Check for electrical hazards, unstable structures, or ongoing threats.

Step 2 — Tap the person’s shoulders firmly and shout their name or “Are you okay?” No response means unconscious.

Step 3 — Look at the chest for 10 seconds. Watch for rise and fall. Occasional gasping (agonal breathing) is NOT normal breathing — it looks like fish-out-of-water gulping and means the brain is starving for oxygen. Treat agonal breathing as no breathing.

Step 4 — Optional pulse check. Place two fingers (not your thumb — it has its own pulse) on the side of the neck in the groove between the windpipe and the large neck muscle. If you cannot feel a pulse within 10 seconds, begin CPR. Do not waste time searching for a pulse — if the person is not breathing normally, start compressions.

Hand Placement

Correct hand position is critical. Too high and you compress the upper chest ineffectively. Too low and you press on the xiphoid process (the small cartilage tip at the bottom of the breastbone), which can break off and puncture the liver.

Step 1 — Place the heel of your dominant hand on the center of the chest, on the lower half of the breastbone (sternum). A reliable landmark: draw an imaginary line between the nipples. Place your hand on the sternum at that line.

Step 2 — Place your other hand directly on top of the first. Interlace your fingers and pull them upward so only the heel of the bottom hand contacts the chest.

Step 3 — Position your shoulders directly over your hands. Lock your elbows. You will compress using your body weight, not arm strength — arm muscles alone will exhaust you within 2 minutes.

Compression Technique

Depth: Push the chest down at least 5 cm (2 inches) but no more than 6 cm (2.4 inches). This feels aggressive. You may hear or feel ribs crack — this is common, especially in older patients. Broken ribs heal. Dead people do not. Continue compressions.

Rate: 100-120 compressions per minute. Count out loud: “one-and-two-and-three-and-four…” at a steady, brisk pace. Each number plus its “and” should take about half a second.

Recoil: Allow the chest to come fully back up between compressions. Do not lean on the chest during the upstroke. Full recoil lets the heart refill with blood. Incomplete recoil dramatically reduces CPR effectiveness.

Minimize interruptions: Every time you stop compressions, blood pressure drops to zero and takes several compressions to rebuild. Keep pauses under 10 seconds.

Common Error	Why It Fails	Correction
Too shallow (<5 cm)	Blood is not adequately circulated	Push harder — use body weight
Too fast (>120/min)	Chest cannot fully recoil between compressions	Count out loud, maintain rhythm
Leaning on chest	Heart cannot refill, reducing output by 25-50%	Lift hands slightly between compressions
Hands too high	Compresses upper sternum, not the heart	Recheck nipple-line landmark
Bent elbows	Arms fatigue in 1-2 minutes	Lock elbows, compress from shoulders

Rescue Breathing

If you are trained and willing, add rescue breaths to improve oxygen delivery. This is especially important for drowning victims, children, and prolonged resuscitation attempts where oxygen in the blood has been depleted.

The cycle: 30 compressions, then 2 breaths. Repeat.

Step 1 — After 30 compressions, tilt the head back by placing one hand on the forehead and lifting the chin with two fingers of your other hand. This opens the airway by moving the tongue away from the back of the throat.

Step 2 — Pinch the nose shut with the hand on the forehead.

Step 3 — Seal your mouth completely over theirs. Deliver one breath over 1 second, watching for the chest to rise. If the chest does not rise, reposition the head tilt and try again.

Step 4 — Give a second breath (1 second). Then immediately resume compressions.

Warning

If the chest does not rise after repositioning, suspect a blocked airway. Perform 30 compressions (which may dislodge the obstruction), check the mouth for visible objects, then attempt breaths again. See Choking Response for airway obstruction protocols.

If you cannot or will not give breaths: Hands-only CPR (continuous compressions without breaths) is still effective, especially in the first 5-10 minutes when residual oxygen remains in the blood. Do not let reluctance to give breaths stop you from doing compressions.

Special Situations

Drowning victims: Always give rescue breaths. Drowning is an oxygen-deprivation emergency — the heart stopped because the lungs stopped. Give 5 initial rescue breaths before starting the 30:2 cycle. CPR success rates for drowning victims are much higher than for other causes.

Hypothermia: Cold-water drowning or severe hypothermia patients may appear dead but can sometimes be revived after prolonged CPR. The cold slows brain metabolism and provides some protection. The saying in emergency medicine: “They’re not dead until they’re warm and dead.” Continue CPR while rewarming (see First Aid for rewarming protocols). CPR may need to continue for over an hour.

Children (ages 1-8): Use one hand instead of two for compressions. Compress approximately one-third of the chest depth (about 5 cm). Give 2 initial rescue breaths before starting compressions, then use a 30:2 ratio.

Infants (under 1 year): Use two fingers (index and middle) placed just below the nipple line. Compress one-third of chest depth (about 4 cm). Cover both the nose and mouth with your mouth for breaths. Use a 30:2 ratio.

Managing Fatigue

Effective CPR is physically exhausting. Quality compressions degrade significantly after about 2 minutes, even in fit individuals.

• If a second rescuer is available, switch every 2 minutes (approximately 5 cycles of 30:2). Switch quickly — aim for under 5 seconds of interruption.
• Kneel close to the patient to reduce strain on your lower back.
• Use your core and body weight, not your arms.
• If alone with no relief, compress as long as you physically can. Even degraded compressions are better than none.

When to Stop

Stop CPR when:

• The person starts breathing normally and has a pulse — move them to the Recovery Position
• You are physically unable to continue and no one can relieve you
• The scene becomes unsafe
• It has been 30 minutes or more with no response (no breathing, no pulse, no signs of life at any point). In the absence of hypothermia or cold-water drowning, survival after 30 minutes of CPR without advanced medical equipment is essentially zero

Key Takeaways

• Start compressions within 10 seconds of confirming no normal breathing — speed matters more than perfection
• Push hard (5 cm), push fast (100-120/min), let the chest fully recoil, and minimize interruptions
• Broken ribs are expected and acceptable — ineffective compressions are not
• Add rescue breaths (30:2 ratio) when possible, especially for drowning and child victims
• If the person recovers, immediately place them in the Recovery Position and monitor continuously — re-arrest is common