Anaesthesia · CPCR/BLS/ACLS Protocols

In ventricular fibrillation (VF) cardiac arrest, the recommended energy for the THIRD defibrillation attempt using a biphasic defibrillator as per current guidelines is:

  • A 200 J for all subsequent shocks
  • B 360 J (maximum monophasic equivalent)
  • C Escalating dose up to 360 J equivalent biphasic for third and subsequent shocks
  • D 150–200 J for second shock; manufacturer's recommended dose for subsequent
Correct answer: C. Escalating dose up to 360 J equivalent biphasic for third and subsequent shocks

Explanation

AHA 2020 and ERC 2021 guidelines recommend: first biphasic shock at 120–200 J (device-specific), second shock at same or higher energy, and third and subsequent shocks at the maximum energy the device allows (approximately 200–360 J for biphasic devices, as equivalent to 360 J monophasic). Current guidance allows escalating energy for refractory VF. Fixed-dose 200 J protocols are device-specific and acceptable if evidence-based. The key principle is that shocks should be followed by immediate resumption of CPR without rhythm check; shocks should not be interrupted by prolonged pauses.

Reference: Morgan & Mikhail's Clinical Anesthesiology, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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