Ventricular Fibrillation Pediatric Dose — Defibrillation
Defibrillation is the definitive electrical treatment for ventricular fibrillation (VF) and pulseless ventricular tachycardia (pVT) in pediatric patients. It delivers an unsynchronized electrical shock to terminate chaotic ventricular activity and restore an organized cardiac rhythm. VF and pVT are shockable rhythms encountered during pediatric cardiac arrest and require immediate recognition and rapid defibrillation as part of the PALS resuscitation algorithm.
Pediatric Dosing
- Initial shock: 2 J/kg unsynchronized
- Subsequent shocks: 4 J/kg unsynchronized
Doses are weight-based and delivered as unsynchronized shocks. The initial energy is 2 J/kg; if VF or pVT persists, increase to 4 J/kg for subsequent attempts. For doses beyond the initial shock, consult institutional protocol regarding maximum energy limits.
Worked example — 20 kg child: Initial shock: 20 × 2 J/kg = 40 J. Subsequent shock: 20 × 4 J/kg = 80 J.
Indications and Clinical Context
Defibrillation at 2–4 J/kg is indicated for pediatric patients in confirmed ventricular fibrillation or pulseless ventricular tachycardia. These are shockable rhythms identified during rhythm analysis in a pulseless arrest. Per PALS guidelines, high-quality CPR should be resumed immediately after each shock without delay for rhythm reassessment, and defibrillation should be integrated into the broader resuscitation cycle including epinephrine and antiarrhythmic therapy as indicated.
Early defibrillation is a time-critical intervention; shorter time-to-shock intervals are associated with improved outcomes. VF is less common in pediatric arrest than in adults but must be promptly identified via cardiac monitoring or AED analysis.
Administration and Monitoring
Deliver defibrillation as an unsynchronized shock using a manual defibrillator or AED with pediatric dose-attenuation capability for smaller children. Select appropriately sized pediatric paddles or self-adhesive pads; ensure good contact and avoid placement over implanted devices. Resume CPR immediately after shock delivery and reassess rhythm after approximately 2 minutes of high-quality CPR.
- Use unsynchronized mode — do not confuse with synchronized cardioversion used for perfusing tachyarrhythmias
- Confirm VF/pVT on monitor before charging to avoid inappropriate shock
- Minimize interruptions to chest compressions; charge the defibrillator while CPR continues
- Monitor for return of spontaneous circulation (ROSC) and post-resuscitation dysrhythmias
- Consult institutional protocol for maximum single-dose energy and escalation strategy
Disclaimer: This article is an educational reference summarizing standard pediatric dosing values. It is not a substitute for clinical judgment. Always verify doses against institutional protocols, the current edition of authoritative references (e.g., Lexicomp, Harriet Lane Handbook, PALS guidelines), the patient’s accurate weight, and any patient-specific factors (renal/hepatic function, allergies, comedications) before administration.