8.1 Arrest Recognition & Systematic Approach

Recognizing Pediatric Cardiac Arrest

Cardiac arrest means the heart is not producing effective forward flow. In children you diagnose it clinically—not by waiting for a perfect monitor strip. The classic recognition package is:

1. Unresponsive (no purposeful response to voice or pain)
2. Absent or abnormal breathing (apnea, only gasping/agonal breaths, or ineffective respiratory effort)
3. No definite pulse within 10 seconds (brachial in infants; carotid or femoral in children)

Agonal gasping is not adequate breathing. Gasps are a late brainstem reflex and count as a sign of arrest, not a reason to skip CPR. On the exam, a vignette that describes an unresponsive child with occasional gasps and no pulse is cardiac arrest—start compressions.

The 10-second rule

Healthcare providers perform a simultaneous breathing and pulse check lasting no more than 10 seconds. If you are not sure a pulse is present, treat as arrest and start CPR. Prolonged pulse hunting is a classic megacode failure mode: every extra second without compressions costs coronary and cerebral perfusion.

Pediatric physiology: why arrest looks different from adults

In adults, sudden collapse is often primary cardiac—ventricular fibrillation (VF) from coronary disease. In infants and children, arrest is usually secondary: progressive respiratory failure (hypoxia → bradycardia → asystole/PEA) or progressive shock (hypoperfusion → metabolic failure → arrest). Primary VF is less common but still possible (channelopathies, myocarditis, congenital heart disease, post-operative settings, electrocution, drug toxicity).

Exam implication: Do not manage a pediatric code as if it were adult ACLS with only smaller drug doses. Prioritize oxygenation, ventilation, and reversible causes while you still apply the shockable/nonshockable branches correctly when VF/pVT appears.

Immediate Actions: CPR, Help, Monitor/Defibrillator

Once arrest is recognized, actions run in parallel, not as a single-file checklist that freezes compressions.

1. Start high-quality CPR within 10 seconds

Begin chest compressions immediately. High-quality pediatric CPR (detailed in Chapter 7) remains the foundation of every advanced intervention:

• Rate 100–120/min
• Depth at least one-third the anterior–posterior chest diameter (about 1.5 in / 4 cm in infants; about 2 in / 5 cm in children)
• Full chest recoil; minimize interruptions
• Avoid excessive ventilation
• Single-rescuer 30:2; two-rescuer 15:2 for infants and children until an advanced airway allows continuous compressions with asynchronous ventilation

2. Activate help and get equipment

Shout for help / activate the emergency response or code team. Send someone for the defibrillator/AED, airway equipment, and code cart. In a lone-rescuer unwitnessed pediatric arrest outside the hospital, current BLS teaching often prioritizes a brief period of CPR before leaving to phone/AED because hypoxia is so often the driver—but once a team is present, tasks are simultaneous.

3. Attach monitor/defibrillator early

Apply pediatric pads or paddles (or an AED with pediatric capability/attenuator when available) as soon as the device arrives. Analyze the rhythm during a brief pause (ideally <10 seconds) and decide the branch:

Do not delay the first shock for IV starts, intubation, or history-taking when VF/pVT is present. Do not shock asystole or PEA.

4. Obtain vascular access without stopping the algorithm

Establish IV or IO access as soon as practical. If peripheral IV attempts fail quickly, place IO rather than spending minutes on veins. Access enables epinephrine and other drugs but never replaces CPR or timely defibrillation.

5. Support airway and ventilation continuously

Because many pediatric arrests are hypoxic, effective bag-mask ventilation with oxygen is lifesaving. Avoid hyperventilation. Consider advanced airway when indicated without prolonged interruptions (Chapter 4). Use quantitative waveform capnography when available to monitor CPR quality and detect ROSC.

Systematic Approach During the Code

After CPR is running and the rhythm branch is known, keep using the PALS evaluate–identify–intervene loop and a simplified ABCDE frame without stopping compressions for leisurely exams.

Circulation priorities during arrest

• Continuous high-quality compressions with planned compressor switches about every 2 minutes
• Rhythm check every ~2 minutes; shock if indicated; immediate resume CPR after any shock
• Epinephrine and other meds on the correct timing (Sections 8.2–8.4)
• Search and treat reversible causes (H’s and T’s)—especially hypoxia and hypovolemia in children

Airway and breathing priorities

• Open airway; bag-mask with oxygen; ensure visible chest rise
• Correct reversible airway obstruction
• Advanced airway if bag-mask is inadequate or prolonged resuscitation is expected—confirm placement and continue high-quality CPR

Disability and exposure (brief, during pauses)

• Glucose check when feasible (hypoglycemia common in critically ill infants)
• Look for trauma, bleeding, rash (anaphylaxis/sepsis), temperature extremes, toxin clues, and medical alert information

Why “secondary arrest” changes team focus

Clinical scenario (synthesis)

A 2-year-old with progressive viral pneumonia becomes unresponsive. The nurse finds only gasping breaths and cannot feel a definite brachial pulse in 8 seconds. This is cardiac arrest. The team starts CPR immediately, calls a code, applies pads, and finds asystole. They continue CPR, bag with oxygen, place IO access, give epinephrine 0.01 mg/kg, and treat hypoxia aggressively—not a defibrillation attempt. Two minutes later the rhythm is organized with a pulse: transition to post-arrest care. If the monitor had shown VF, the first action after recognition would have been defibrillation (teaching first dose 2 J/kg), then immediate CPR.

Bottom line for 8.1: Unresponsive + abnormal breathing/gasping + no definite pulse ≤10 s → CPR within 10 seconds → monitor/defibrillator → shockable vs nonshockable → continuous high-quality CPR, access, airway/ventilation, and reversible causes. Pediatric arrest is usually secondary to respiratory failure or shock—treat that reality while executing the algorithm precisely.