Distinguish a compensatory fast rate from the adenosine or urgent-cardioversion pathway.
OCEMS source summary · Updated 2026-09-16
Key cautions & base contact
Do not administer adenosine to a wide, irregular rhythm.
A regular narrow rhythm does not by itself prove a primary arrhythmia; assess suspected hypovolemia and stability first.
Confirm the rhythm & assess perfusion
This adult order applies to a regular rhythm above 100/min with QRS width below 0.12 seconds. Record a rhythm strip.
Assess BP, consciousness, chest symptoms, oxygenation, and evidence of hypovolemia. Provide oxygen for SpO₂ below 95% as described by the source.
Address suspected volume depletion
For suspected hypovolemia with clear lungs/no CHF, give 250 mL normal saline, repeating up to 1 L to maintain perfusion.
Reassess lung sounds; stop fluid infusion if rales develop. This assessment applies to both the 100–150 range and the faster-rate pathway.
Rate at least 150: choose the branch
With mild chest discomfort, lightheadedness, or diaphoresis: attempt Valsalva. If the regular narrow-complex rhythm persists, give adenosine 12 mg rapid IV; may repeat once after 3 minutes.
With cardiac chest discomfort, altered mental status, or systolic BP below 90: synchronized cardioversion at 100 J initially, then once at maximum energy if needed, or use the manufacturer’s recommended settings.
Reassess & transport
Document conversion or persistent rhythm and reassess BP, consciousness, chest symptoms, and perfusion. Provide ALS escort to the nearest ERC or contact base as needed.
A regular rate near 150 may represent flutter and may not respond to adenosine. The source warns that an unstable patient may require immediate cardioversion without premedication; if synchronization fails, unsynchronized treatment may be needed.