3.3 Infant CPR: Two Fingers, Two Thumbs, and Ventilation

Hand Placement and Technique

Infant compressions are delivered on the lower half of the sternum, just below the nipple (intermammary) line, avoiding the xiphoid. Two techniques are tested, and the correct one depends on the number of rescuers:

• Two-finger technique (lone rescuer): place two fingers on the lower sternum. This lets a single rescuer compress and then quickly move to the head to ventilate.
• Two-thumb–encircling-hands technique (two rescuers): encircle the infant's chest with both hands, place both thumbs side by side (or stacked on a tiny infant) on the lower sternum, and compress with the thumbs while the fingers support the back. The AHA prefers this technique when two rescuers are present because it produces higher coronary artery perfusion pressure and more consistent depth and force than two fingers. If a lone rescuer cannot reach adequate depth with two fingers, it is reasonable to use the heel of one hand.

Compress about one third of the chest's anterior-posterior diameter, roughly 1.5 inches (4 cm), at 100–120/min, with full recoil and minimal interruptions. As with children, the most common error is too-shallow compression.

Assessment

Check a pulse at the brachial artery (inner upper arm) — the carotid is impractical on a short infant neck. Take no more than 10 seconds. If there is no pulse, or a pulse under 60/min with poor perfusion, begin compressions.

Ratios, Ventilation, and the AED

Infant ratios mirror the child's and turn on rescuer count:

Ventilation must be gentle: deliver just enough air over about 1 second to produce visible chest rise. Over-aggressive breaths inflate the stomach (gastric insufflation), raise the risk of regurgitation and aspiration, and impede the diaphragm. If the chest does not rise, the most likely problem is airway position — reopen the airway with a head-tilt/chin-lift to a neutral "sniffing" position (an infant's large occiput tends to flex the neck) and try again. Do not simply squeeze the bag harder.

For a pulseless infant, the defibrillation priority order is: a manual defibrillator (preferred, set to 2 J/kg first dose), then an AED with a pediatric dose attenuator, and only if neither is available, a standard AED.

Rescue Breathing for an Infant With a Pulse

If an infant has a pulse but inadequate or absent breathing, give rescue breathing at 1 breath every 2 to 3 seconds (20 to 30 breaths per minute) — the rate raised in the 2020 AHA update from the older 12–20/min. Reassess the pulse and breathing at least every 2 minutes. This faster pediatric rate is a frequent test point: it is much faster than the adult rescue-breathing rate of 1 breath every 6 seconds (10/min), reflecting the infant's higher metabolic demand and the asphyxial nature of pediatric deterioration.

Scenario: an infant is pulseless and apneic with two rescuers present. One rescuer applies the two-thumb–encircling-hands technique at 15:2 while the other ventilates to chest rise; if a breath fails to move the chest, the airway is repositioned before the next attempt.

Skills Testing and the Mechanics That Get Graded

Infant CPR is a hands-on skill graded in the AHA BLS course, so questions often probe the precise mechanics an instructor watches for. For the two-thumb–encircling-hands technique, the thumbs sit side by side over the lower half of the sternum (stacked for a very small infant), the fingers wrap around the thorax to support the back, and the rescuer can gently squeeze the thorax with the encircling hands to augment each compression — while still allowing full recoil so the chest re-expands completely. For the two-finger technique, two fingertips press the lower sternum just below the imaginary line connecting the nipples.

5 inches (4 cm)**.

A practical detail that shows up in scenarios: when a lone rescuer using two fingers must move to the head to ventilate after every 30 compressions, the airway is opened to a neutral or slightly extended "sniffing" position — over-extending an infant's neck can kink the soft trachea and obstruct the airway, while under-extension lets the tongue fall back. Both extremes produce a chest that will not rise.

Coordinating Two Rescuers and Avoiding Hyperventilation

With two rescuers, the compressor and ventilator coordinate the 15:2 cadence: the compressor pauses briefly after 15 compressions so the ventilator can deliver 2 breaths to chest rise, then compressions resume. The most common quality failure in pediatric resuscitation is over-ventilation — too many breaths or too much volume. This raises intrathoracic pressure, reduces venous return, and lowers cardiac output, and in an infant it also distends the small stomach and forces regurgitation. The fix is discipline: each breath is a gentle puff to visible chest rise over about 1 second, no more.

Rotating compressors every 2 minutes preserves depth, exactly as in adult and child CPR. A useful habit during any infant resuscitation is to count compressions aloud, so the partner can anticipate the pause for ventilations and so the rate does not drift below 100 or climb above 120 per minute, both of which reduce the blood flow each compression generates.