Perform chest compressions for a child at a rate of 100 to 120 per minute. Push hard to about one-third the depth of the chest, let the chest recoil fully, and minimize interruptions. The American Heart Association sets this rate for children and for adults alike, and the number is not arbitrary.
Rate is the variable most easily lost in a real resuscitation, and it drifts in predictable directions. Untrained and trained rescuers alike tend to start too fast. Fatigue then drags the rate down. Both errors degrade the one thing compressions exist to do: keep enough oxygenated blood moving to the brain until circulation returns or advanced care arrives.
The hemodynamics of compression rate
Every compression is a small pump stroke. The chest wall and heart are squeezed between the sternum and spine, and blood is ejected into the aorta and pulmonary arteries. Release lets the chest spring back, and the resulting negative intrathoracic pressure pulls blood back into the heart. This is why recoil matters as much as the push.
Cardiac output during CPR is the product of stroke volume and compression rate. Stroke volume is small, perhaps 20 to 30 percent of normal at best, which is why rate cannot be allowed to sag. But rate and stroke volume trade against each other. Beyond a certain frequency, the heart does not have time to refill between compressions, and each subsequent stroke gets smaller.
There is a second reason the ceiling exists. Coronary perfusion pressure, the gradient that drives blood into the heart muscle itself, depends on the duration of the release phase. That pressure builds during diastole, when the chest is relaxed. Compress too fast and the diastolic window shrinks, coronary flow falls, and the heart has less chance to restart. Too slow and total forward flow drops, starving the brain.
The 100–120 window is the compromise the evidence supports. It keeps minute output high enough while preserving a diastolic interval long enough for coronary filling. The physiology is the same in a child and an adult; only the depth, and the force needed to reach it, differ.
What the numbers mean in context
The pediatric rate matches the adult rate, but the reason is worth stating plainly: the compression rate is set by what the heart needs, not by the size of the patient. Depth scales with body size. Rate does not.
The AHA's 2020 guidelines set high-quality CPR at 100 to 120 compressions per minute for all ages, with a compression-to-ventilation ratio of 30:2 for a single rescuer and 15:2 for two rescuers trained in pediatric resuscitation. Depth for a child is at least one-third the anterior-posterior chest diameter, roughly 5 cm (about 2 inches). For an infant under 1 year, the technique changes to two fingers or two thumbs, but the same rate window applies.
Minute output is easier to grasp as a fraction. Normal resting cardiac output in a child is roughly 3 to 4 L/min, indexed to body surface area. CPR generates a small fraction of that, often cited as 10 to 30 percent of baseline. At 100 compressions per minute, that is 100 pump strokes per minute of a small volume. At 80, you lose a fifth of your strokes. At 140, you gain strokes but lose filling.
Hands-on time is the operational lever. A resuscitation with good rate but frequent pauses can have compression fractions below 60 percent. The AHA target is a chest compression fraction above 60 percent, ideally higher. Two rescuers should swap every 2 minutes, before fatigue erodes both rate and depth.
Table 1: Rate alternatives and their trade-offs
| Compression rate (per min) | Forward flow | Coronary filling | Practical note |
|---|---|---|---|
| Under 80 | Low minute output | Adequate diastolic time | Common with fatigue; brain and heart underperfused |
| 80–100 | Marginal | Good | Below the guideline window; acceptable only transiently |
| 100–120 | Guideline target | Preserved | The evidence-supported compromise |
| 120–140 | Higher but falling stroke volume | Shortened diastole | Rate often drifts here unintentionally |
| Over 140 | Refill incomplete | Reduced | Fast, shallow, ineffective pushes; recoil often lost |
The counterintuitive detail: faster is not better. Rescuers who sprint at 140 to 150 per minute often compress too shallowly because the pace outruns the mechanics. The result looks vigorous and moves less blood.
Where the guidance gets nuanced
The rate recommendation is stable across pediatric and adult guidelines, but several edge cases change how you apply it.
An infant under 1 year is not a small child for compression purposes. Use two fingers or the two-thumb encircling technique, and keep the same 100–120 rate. The depth target is about 4 cm (1.5 inches), or one-third the chest diameter. Rate stays constant while technique changes.
A child in cardiac arrest from a respiratory cause is common in pediatrics. Hypoxia precedes arrest far more often than in adults. That is why the pediatric sequence emphasizes ventilation, and why two-rescuer teams use 15:2 rather than 30:2. If you are alone, the AHA still directs you to call for help and begin CPR with compressions, but ventilation quality matters more in children than the adult-focused mantra implies.
An adolescent who has reached puberty is treated with adult depth and technique, but the rate window is unchanged. There is no pediatric-specific rate that differs from the adult rate.
A witnessed sudden collapse in a child, especially during sports, raises the possibility of a shockable rhythm. In that setting, an automated external defibrillator should be applied as soon as it arrives, and compressions should resume immediately after each shock. The rate does not change, but the pauses around defibrillation are where compression fraction is lost.
Rescue-breathing and compression red flags
Compressions faster than 120 per minute, often accompanied by shallow depth and incomplete recoil. Leaning on the chest between compressions, which prevents refill and raises intrathoracic pressure. Pauses longer than 10 seconds for breathing, pulse checks, or rescuer changes. Ratio drift: single rescuers defaulting to 15:2 or forgetting to ventilate entirely. Depth short of one-third chest diameter, especially as fatigue sets in after 2 minutes. Chest compression fraction below 60 percent, usually from stacking interruptions.
Misconceptions that degrade real CPR
The most common misconception is that a faster rate compensates for shallow compressions. It does not. Stroke volume depends on depth and recoil, and rate cannot rescue a stroke that was never generated. Speed without depth produces a flurry of useless motion.
Another is that the pediatric rate differs from the adult rate. It does not. What differs is depth, hand placement, compression-to-ventilation ratio, and the emphasis on ventilation. Rescuers who learn "child CPR" sometimes internalize a different tempo, which adds confusion in a crisis.
A third is that pulse checks should be frequent and thorough. In practice, pulse checks are the main source of pause time. The AHA limits pulse checks to no more than 10 seconds, and in children with a likely hypoxic cause, the emphasis is on minimizing any interruption.
A fourth is that compressions alone are sufficient in children. For a hypoxic arrest, ventilation restores the oxygen that compressions are trying to circulate. Compressions move blood; they do not oxygenate it.
Table 2: The first minutes of pediatric CPR
| Time from recognition | Action | Rate and ratio focus |
|---|---|---|
| 0–10 seconds | Confirm unresponsiveness and abnormal breathing | Call for help; begin compressions |
| 10–30 seconds | First compression cycle | 100–120/min; 30:2 solo or 15:2 two rescuers |
| 30 seconds–2 minutes | Continue cycles; apply AED when available | Keep pauses under 10 seconds |
| 2 minutes | First rescuer swap | Swap before fatigue drops rate or depth |
| 2–4 minutes | Continue cycles; advanced help en route | Maintain compression fraction above 60 percent |
| 4 minutes onward | Ongoing cycles with 2-minute swaps | Reassess rhythm per protocol |
This timeline is a general teaching framework, not a patient-specific protocol. Actual resuscitation follows local emergency medical protocols and the guidance of arriving clinicians.
Practical actions for hitting the target
Use a metronome or a familiar song at 100 to 120 beats per minute. Many training programs use songs in that tempo range, and the beat removes the guesswork. If no metronome is available, count aloud in a steady cadence and have a second rescuer watch the clock.
Push to one-third the chest depth, which for most children is about 5 cm (2 inches). Let the chest come all the way back up between compressions. Do not lean on the chest during the release phase.
Keep interruptions under 10 seconds. That includes pulse checks, rhythm analysis, and rescuer changes. Prepare the swap before you make it, and perform it during the release phase rather than as a separate pause.
Swap rescuers every 2 minutes. Fatigue is the main cause of rate decay and depth loss. A fresh rescuer at 2 minutes preserves quality better than a tired one at 4.
Maintain the compression-to-ventilation ratio for your team size: 30:2 if you are alone, 15:2 if two trained rescuers are present. Deliver each breath over about 1 second and watch for visible chest rise.
Call emergency services immediately and apply an AED as soon as it is available. In a child, the AED should be used with pediatric pads or an attenuator if available, and compressions resume right after each shock.
Limits of the evidence and what rate cannot fix
The 100–120 window rests on physiologic reasoning and observational data, not on large randomized trials in children. Pediatric cardiac arrest is uncommon, and trials that isolate compression rate as a variable are scarce. The recommendation is extrapolated from adult and animal evidence plus pediatric consensus.
Rate is also only one component of high-quality CPR. Depth, recoil, compression fraction, and ventilation all interact with it. A resuscitation with perfect rate and poor depth will underperform one with slightly imperfect rate and excellent depth and recoil. No single number guarantees return of circulation.
Outcomes after pediatric cardiac arrest remain poor, and in-hospital arrest survival to discharge is substantially higher than out-of-hospital arrest survival. Rate optimization is one lever among several, and it cannot compensate for delayed recognition or prolonged pauses.
This article is general educational information about CPR physiology and guideline-based technique, not a diagnosis, treatment plan, or substitute for certified training. It does not promise any outcome. Learn CPR through a recognized course and follow local emergency protocols; for an actual emergency, call your local emergency number immediately.