What treatment should be administered as soon as feasible in a cardiac arrest patient with no pulse?

Immediate Treatment for Cardiac Arrest Without Pulse

Initiate high-quality CPR immediately with chest compressions at 100-120 per minute and a depth of 5-6 cm, and administer epinephrine 1 mg IV/IO as soon as feasible—the specific timing depends on whether the rhythm is shockable or non-shockable. 1, 2

Initial Management Algorithm

Step 1: Confirm Cardiac Arrest and Begin CPR

• Check for pulse within 10 seconds while simultaneously assessing for normal breathing 1, 2
• If no pulse is detected, immediately begin chest compressions before any other intervention 2, 3
• Perform compressions at 100-120 per minute with depth of 5-6 cm, allowing complete chest recoil between compressions 1, 2, 3
• Use 30:2 compression-to-ventilation ratio for adults 3
• Minimize interruptions in compressions—this is critical for survival 2, 3

Step 2: Establish IV/IO Access and Prepare Medications

• Establish intravenous or intraosseous access as soon as possible 2
• IV administration is preferred, but if unsuccessful, IO access should be utilized immediately 4

Step 3: Rhythm-Specific Epinephrine Administration

For Non-Shockable Rhythms (Asystole/PEA):

• Administer epinephrine 1 mg IV/IO as soon as feasible—ideally within 1-3 minutes of arrest 1
• This is a strong recommendation from the 2022 International Consensus guidelines 1
• Earlier administration significantly improves outcomes: each 3-minute delay decreases survival (adjusted OR 0.91 for 4-6 minutes, 0.74 for 7-9 minutes, 0.63 for >9 minutes compared to 1-3 minutes) 5
• Repeat epinephrine 1 mg every 3-5 minutes throughout the resuscitation 1, 2

For Shockable Rhythms (VF/pVT):

• Deliver shock immediately, then resume CPR for 2 minutes 2, 3
• Administer epinephrine 1 mg IV/IO after initial defibrillation attempts are unsuccessful 1
• This is a weaker recommendation as epinephrine shows benefit for ROSC but uncertain effect on neurological outcomes in shockable rhythms 1
• Repeat epinephrine 1 mg every 3-5 minutes 1, 2

Step 4: Consider Antiarrhythmics for Refractory VF/pVT

• For refractory VF/pVT (after multiple shocks), consider amiodarone 300 mg IV/IO bolus 1, 2, 4
• Alternative: lidocaine 1 mg/kg IV/IO if amiodarone unavailable 1
• Important caveat: Antiarrhythmics likely do not improve survival or neurologic outcomes, but may be considered for rhythm control 4

Critical Timing Considerations

The evidence strongly supports time-dependent benefit of epinephrine in non-shockable rhythms—median time to first dose should be 3 minutes, with stepwise worsening outcomes for each delay 5. For non-shockable rhythms, there should be no delay in epinephrine administration once IV/IO access is established 1.

Common Pitfalls to Avoid

• Do not delay compressions to establish IV access or administer medications—compressions take absolute priority 2, 3
• Do not interrupt compressions for more than 10 seconds except for defibrillation 3
• Do not routinely administer calcium or sodium bicarbonate—these are not indicated in standard cardiac arrest 4
• Do not use vasopressin instead of or in addition to epinephrine—evidence shows no benefit 1
• Change compressor every 2 minutes to prevent fatigue-related decline in compression quality 3

Important Evidence Nuances

While epinephrine improves ROSC and short-term survival, the evidence for improved neurologically intact survival remains uncertain 1, 4. The 2019 ILCOR review noted that epinephrine increases survival to discharge but has not been definitively shown to increase survival with favorable neurological outcome 1. However, given the strong evidence for improved ROSC and survival, and the lack of superior alternatives, epinephrine remains the standard of care with strong guideline support 1.