How can I confirm true return of spontaneous circulation (ROSC) instead of a transient epinephrine‑induced pulse?

Confirming True ROSC vs. Transient Epinephrine-Induced Pulse

True return of spontaneous circulation (ROSC) requires sustained perfusion lasting at least 30 seconds with evidence of more than an occasional gasp, sustained palpable pulse, or measurable arterial waveform—not just a fleeting pulse that disappears within seconds after epinephrine administration. 1

Defining True ROSC

The International Liaison Committee on Resuscitation consensus defines ROSC as restoration of spontaneous perfusing rhythm that produces:

• More than occasional gasping 1
• Sustained palpable pulse (not fleeting or intermittent) 1
• Measurable blood pressure 1
• Visible arterial waveform on invasive monitoring 1

The critical distinction is duration: "any ROSC" represents approximately 30 seconds of sustained spontaneous circulation, not just a transient pulse that lasts only a few seconds. 1

Clinical Signs That Confirm True ROSC

Primary Indicators

• Breathing (more than occasional gasps) 1
• Coughing 1
• Purposeful movement 1
• Palpable carotid pulse that persists beyond 30 seconds 1, 2
• Measurable blood pressure (target mean arterial pressure ≥65 mmHg) 3, 2

Objective Monitoring Parameters

End-tidal CO₂ (PETCO₂) is the most reliable real-time indicator:

• Abrupt sustained increase in PETCO₂ to ≥40 mmHg strongly suggests ROSC 3, 2, 4
• In one study, PETCO₂ increased significantly from 41 mmHg three minutes before ROSC to 57 mmHg one minute after ROSC 4
• PETCO₂ values are significantly higher with pulsed rhythms (46 mmHg) compared to pulseless electrical activity (20 mmHg) 4

Arterial line monitoring (if available):

• Spontaneous arterial pressure waveforms confirm perfusing rhythm 3, 2
• Provides continuous real-time assessment superior to manual pulse checks 2

How to Distinguish Epinephrine-Induced Pulse from True ROSC

Characteristics of Transient Epinephrine Pulse

An epinephrine-induced pulse typically:

• Appears within 1-2 minutes after epinephrine administration (epinephrine is given every 3-5 minutes) 1, 3
• Lasts only seconds to <30 seconds before disappearing 1
• Shows no sustained increase in PETCO₂ 4
• Produces no spontaneous breathing, coughing, or movement 1
• Does not generate measurable blood pressure 1

Characteristics of True ROSC

True ROSC demonstrates:

• Sustained pulse >30 seconds that persists between epinephrine doses 1
• Abrupt sustained rise in PETCO₂ ≥40 mmHg 3, 4
• Clinical signs of perfusion: breathing, coughing, movement 1
• Measurable blood pressure 1, 3
• Persistent arterial waveform if invasive monitoring present 3

Practical Algorithm for Confirmation

Step 1: During CPR Cycles

• Do NOT check pulse immediately after shock delivery or epinephrine administration—this wastes critical compression time 3, 2
• Continue CPR for full 2-minute cycles 3, 5
• Monitor PETCO₂ continuously during compressions 3, 4

Step 2: At 2-Minute Rhythm Check

• Pause compressions briefly (<10 seconds) 3, 5
• Check monitor for organized rhythm 3
• If organized rhythm present, immediately check carotid pulse 2, 5
• Simultaneously observe for breathing, coughing, or movement 1

Step 3: If Pulse Detected

Confirm sustained ROSC by assessing ALL of the following:

1. Pulse persists >30 seconds (time it) 1
2. PETCO₂ shows abrupt sustained increase ≥40 mmHg 3, 4
3. Patient demonstrates breathing (not just gasps), coughing, or movement 1
4. Blood pressure is measurable (obtain immediately) 1, 3

If pulse disappears within seconds: This was likely a transient epinephrine effect—immediately resume CPR 1, 3

If all criteria met for >30 seconds: True ROSC is confirmed—transition to post-ROSC care 1, 3

Step 4: Post-ROSC Confirmation

Once ROSC is suspected, do not resume compressions prematurely—instead:

• Obtain blood pressure measurement (target MAP ≥65 mmHg) 3, 2
• Verify sustained PETCO₂ ≥40 mmHg 3, 4
• Assess for spontaneous respirations 1
• Obtain 12-lead ECG immediately 3, 5

Common Pitfalls and How to Avoid Them

Pitfall 1: Checking Pulse Too Frequently

Problem: Interrupting compressions for pulse checks reduces coronary perfusion pressure and decreases ROSC likelihood 3, 5

Solution: Only check pulse at designated 2-minute intervals during rhythm analysis, or when PETCO₂ shows abrupt sustained increase suggesting ROSC 3, 5

Pitfall 2: Mistaking Transient Pulse for ROSC

Problem: Stopping CPR after detecting a fleeting pulse that disappears within seconds 1

Solution: Require sustained pulse >30 seconds PLUS confirmatory signs (PETCO₂ increase, breathing, measurable BP) before declaring ROSC 1, 3, 4

Pitfall 3: Checking Pulse Immediately After Epinephrine or Shock

Problem: Wastes critical time when compressions should be ongoing; any pulse detected is likely transient 3, 2

Solution: Immediately resume compressions after shock or medication and continue for full 2-minute cycle 3, 5

Pitfall 4: Relying on Manual Pulse Check Alone

Problem: Manual pulse assessment can be unreliable and does not confirm adequate perfusion 2

Solution: Use multiple confirmation methods: sustained pulse PLUS PETCO₂ increase PLUS clinical signs PLUS measurable blood pressure 3, 2, 4

Pitfall 5: Prolonged Pulse Checks

Problem: Pulse checks >10 seconds significantly worsen outcomes 3, 5

Solution: Limit pulse checks to <10 seconds; if uncertain about pulse presence, immediately resume compressions 3, 5

Evidence for PETCO₂ as Superior Indicator

Machine learning analysis combining ECG, thoracic impedance, and PETCO₂ achieved:

• Area under curve of 0.92 for pulse detection 4
• Sensitivity 96.6% and specificity 94.5% for ROSC detection 4
• Adding PETCO₂ improved performance by >2 percentage points over ECG and impedance alone 4

This evidence strongly supports using PETCO₂ as the primary objective indicator to distinguish true ROSC from transient epinephrine-induced pulses. 4

Post-ROSC Stability Indicators

Even after confirming ROSC, sustained ROSC (defined as lasting until hospital admission for out-of-hospital arrests, or 20 minutes for in-hospital arrests) requires:

• Normal heart rate 6
• Normal blood pressure (MAP ≥65 mmHg) 3, 6
• Urine output >1 mL/kg/hour 6
• Normal skin color 6

Rearrest occurs in approximately 36% of patients after initial ROSC, with median time to rearrest of 3.1 minutes. 7 Therefore, continuous monitoring for at least 20 minutes is essential to confirm sustained ROSC versus transient ROSC. 1, 7