What is the recommended joule dose for defibrillating a 3-year-old child?

Defibrillation Energy Dose for a 3-Year-Old Child

For a 3-year-old child in ventricular fibrillation or pulseless ventricular tachycardia, deliver an initial defibrillation dose of 2 J/kg, which translates to approximately 28-32 joules for an average 3-year-old weighing 14-16 kg. 1

Initial Defibrillation Strategy

• Use 2 J/kg as the initial dose for ease of teaching and consistency with current American Heart Association guidelines, though a range of 2-4 J/kg is considered reasonable. 1

• For a typical 3-year-old weighing approximately 14-16 kg, this equates to 28-32 joules for the first shock. 1

• A manual defibrillator is strongly preferred when available, as it allows precise weight-based dosing titration for this age group. 1

• If using an automated external defibrillator (AED), use one with pediatric attenuator pads that reduce the energy dose to appropriate pediatric levels. 1, 2

Critical Procedural Points

• Deliver a single shock followed immediately by chest compressions—do not deliver stacked shocks. 1

• Minimize interruptions in chest compressions to less than 10 seconds for rhythm checks and shock delivery. 1

• Continue CPR for approximately 2 minutes (5 cycles) before rechecking the rhythm. 1

• Use the largest pediatric pads that fit on the chest without touching each other (typically 4.5 cm diameter for this age). 1

Subsequent Shock Dosing

• If VF/pVT persists after the first shock, increase to 4 J/kg (approximately 56-64 joules for a 14-16 kg child). 1

• For refractory VF/pVT, subsequent doses of 4 J/kg are reasonable, with consideration of higher doses up to 10 J/kg or adult maximum dose (whichever is lower). 1

• Recent high-quality evidence from the 2020 Get With the Guidelines-Resuscitation database (422 pediatric patients) demonstrated that first shock doses outside the 1.7-2.5 J/kg range were associated with lower survival in children ≤12 years, particularly for initial VF. 3

Important Clinical Caveats

Weight estimation is critical but challenging: If the child's exact weight is unknown, use length-based resuscitation tapes (Broselow tape) or cognitive aids to estimate weight, though these tend to underestimate actual body weight. 1

The 2 J/kg dose controversy: While 2 J/kg has been standard for decades based on limited evidence from a 1976 study of only 27 children, some data suggest this may be suboptimal for terminating VF. 1, 4 However, the most recent 2020 registry data strongly supports 2 J/kg (1.7-2.5 J/kg range) as associated with better survival outcomes. 3

AED considerations for young children: If a manual defibrillator is unavailable, an AED with pediatric attenuator is preferred. 1, 2 If no pediatric-capable device exists, use an adult AED rather than withholding defibrillation, as untreated VF is uniformly fatal. 2 A case report documented successful defibrillation of a 3-year-old with 150 J (9 J/kg) without myocardial damage, though this exceeds recommended dosing. 1

Medication Timing

• Establish intravenous or intraosseous access during the second cycle of CPR if sufficient rescuers are available. 1

• Administer epinephrine 0.01 mg/kg (0.1 mL/kg of 1:10,000) IV/IO after the second shock if VF/pVT persists, then every 3-5 minutes. 1, 5

• Consider amiodarone 5 mg/kg IV/IO after the third shock for refractory VF/pVT. 1, 5

Device Selection Priority

1. Manual defibrillator with pediatric paddles/pads (first choice) 1, 5
2. AED with pediatric attenuator (second choice) 1, 2
3. Standard adult AED (only if no other option available—do not withhold defibrillation) 2

The evidence strongly supports immediate defibrillation at 2 J/kg over delaying to calculate alternative doses, as time to defibrillation is the most critical determinant of survival in pediatric VF/pVT. 1