Separate stable transport from unstable synchronized cardioversion and medication steps.
OCEMS source summary · Updated 2026-09-16
Key cautions & base contact
Use synchronized cardioversion for the pulsed pathway and confirm synchronization before each shock.
Do not substitute the 300 mg arrest amiodarone dose for this 150 mg slow-infusion pathway.
Assess and document
Confirm a pulse, monitor rhythm, and obtain a rhythm strip or 12-lead. Assess BP, mental status, chest symptoms, and perfusion.
If an implanted defibrillator fires at least twice in 15 minutes, contact base for possible CVRC destination. For SpO₂ below 95%, provide oxygen as directed by the source.
Stable patient
The stable branch describes systolic BP above 90, appropriate mental status, and minimal chest discomfort. Monitor serial vital signs and provide ALS escort to the nearest ERC.
The treatment guideline favors transport without cardioversion or pharmacologic treatment for stable wide-complex tachycardia. Continue looking for deterioration.
Unstable patient
Systolic BP at or below 90, altered consciousness, chest pain, or poor perfusion activates the unstable branch. Synchronized cardioversion starts at 100 J biphasic or the manufacturer-recommended setting; do not delay for IV access if deteriorating.
If unsuccessful, give amiodarone 150 mg slow IV/IO OR lidocaine 1 mg/kg IV/IO. After 2–3 minutes of infusion, persistent unstable tachycardia leads to synchronized full-output/manufacturer-setting cardioversion.
If persistent, repeat amiodarone 150 mg slow IV/IO OR lidocaine 0.5 mg/kg IV/IO, followed after 2–3 minutes by the next synchronized cardioversion step if needed.
Reassess and transport
Reassess pulse, rhythm, BP, consciousness, and perfusion after every intervention. Amiodarone can cause hypotension, especially if administered too rapidly.
Provide ALS escort to the nearest ERC or contact base as needed. If the pulse is lost, switch immediately to the arrest pathway.