Rhythm check. Not shockable leads to CPR 2 min and treat reversible causes. Shockable leads to step 5
Step 12 (no shockable rhythm at check)
No signs of ROSC: go to step 10.
ROSC: go to post-cardiac arrest care.
Consider appropriateness of continued resuscitation.
Key contrast
Shockable: shock first; epinephrine starts after the second shock; amiodarone or lidocaine after the third shock.
Nonshockable: never shock; epinephrine as soon as possible.
Circular algorithm
The circular version shows the same care as a loop: continuous CPR, rhythm check every 2 minutes, shock if VF/pVT, and between checks give drug therapy (IV/IO access, epinephrine every 3-5 minutes, amiodarone or lidocaine for refractory VF/pVT), consider an advanced airway with quantitative waveform capnography, treat reversible causes, and monitor CPR quality. ROSC exits the loop to post-cardiac arrest care.
Change compressor every 2 minutes, or sooner if fatigued.
No advanced airway: 30:2 compression-ventilation ratio.
Advanced airway in place: 1 breath every 6 seconds (10 breaths/min) with continuous chest compressions.
Continuous waveform capnography. If ETCO2 is low or decreasing, reassess CPR quality.
Shock energy for defibrillation
Biphasic: manufacturer recommendation (for example, initial dose 120-200 J); if unknown, use the maximum available. Second and later doses should be equivalent, and higher doses may be considered.
Monophasic: 360 J.
Drug therapy (arrest)
Drug
Dose
Epinephrine IV/IO
1 mg every 3-5 minutes
Amiodarone IV/IO
First dose 300 mg bolus; second dose 150 mg
Lidocaine IV/IO (alternative to amiodarone)
First dose 1-1.5 mg/kg; second dose 0.5-0.75 mg/kg
Advanced airway
ET intubation or supraglottic advanced airway.
Continuous waveform capnography or capnometry to confirm and monitor ET tube placement.
Reversible causes (Hs and Ts)
Hs
Ts
Hypovolemia
Tension pneumothorax
Hypoxia
Tamponade, cardiac
Hydrogen ion (acidosis)
Toxins
Hypo-/hyperkalemia
Thrombosis, pulmonary
Hypothermia
Thrombosis, coronary
Adult Bradycardia With a Pulse
Assess appropriateness for clinical condition. Heart rate is typically < 50/min if bradyarrhythmia.
Cardiopulmonary compromise? (see signs above)
No: identify and treat underlying causes (support ABCs, consider oxygen, obtain 12-lead ECG) and observe.
Yes: assessment and support. Maintain patent airway and provide oxygen; assist breathing with positive-pressure ventilation as necessary; attach cardiorespiratory monitor; monitor pulse.
Bradycardia persists with cardiopulmonary compromise?
No: treat underlying causes and observe.
Yes: give atropine.
If atropine is ineffective: transcutaneous pacing and/or dopamine or epinephrine infusion.
Consider expert consultation and transvenous pacing.
Doses
Drug
Dose
Atropine IV
1 mg bolus; repeat every 3-5 minutes; maximum total 3 mg
Dopamine IV infusion
5-20 mcg/kg per minute; titrate to response; taper slowly
Epinephrine IV infusion
2-10 mcg per minute; titrate to response
Possible causes
Myocardial ischemia/infarction.
Drugs/toxicologic (for example, calcium channel blockers, beta-blockers, digoxin).
Hypoxia.
Electrolyte abnormality (for example, hyperkalemia).
Adult Tachyarrhythmia With a Pulse
Assess appropriateness of heart rate for clinical condition. Heart rate is typically >= 150/min if tachyarrhythmia.
Initial assessment and support:
maintain patent airway; assist breathing as necessary;
oxygen (if hypoxemic);
continue cardiac monitoring to identify rhythm; monitor blood pressure and oximetry;
Yes: consider adenosine only if regular and monomorphic; antiarrhythmic infusion; expert consultation.
No (narrow): vagal maneuvers (if regular); adenosine (if regular); beta-blocker or calcium channel blocker; consider expert consultation.
If refractory, consider: the underlying cause; need to increase energy for the next cardioversion; addition of an antiarrhythmic drug; expert consultation.
Doses
Treatment
Dose/details
Synchronized cardioversion
Use the device’s recommended energy level or the 2025 Guidelines to maximize first-shock success; if not known, use the maximum energy setting
Adenosine IV
First dose 6 mg rapid IV push, follow with NS flush; second dose 12 mg if required
Procainamide IV (stable wide-QRS)
20-50 mg/min until arrhythmia suppressed, hypotension ensues, QRS widens > 50%, or maximum 17 mg/kg given. Maintenance 1-4 mg/min. Avoid if prolonged QT or CHF
Amiodarone IV (stable wide-QRS)
First dose 150 mg over 10 minutes; repeat as needed if VT recurs. Then maintenance infusion 1 mg/min for the first 6 hours
Nursing Pearls
Synchronized cardioversion is for an unstable patient with a pulse; unsynchronized defibrillation is for pulseless VF/pVT. Sedate before cardioversion when feasible.
Adenosine is given as a rapid IV push followed immediately by a saline flush (half-life is seconds); warn the patient about a brief feeling of doom or flushing and expect a short pause on the monitor.
Atropine maximum is 3 mg total. If it fails, move to pacing or a dopamine/epinephrine infusion rather than repeating.
Procainamide is avoided with prolonged QT (see prolonged-qtc).
Asystole and PEA are never shocked; the priority is CPR, early epinephrine, and finding a reversible cause (Hs and Ts).