During cardiac arrest, which pulse should be assessed with a Doppler device, and is checking a vulvar or labial pulse ever appropriate?

Doppler Pulse Assessment During Cardiac Arrest

During cardiac arrest, Doppler ultrasound should be used to assess the carotid artery pulse, not vulvar or labial pulses, which have no role in cardiac arrest management. 1

Why Manual Pulse Checks Are Inadequate

The traditional carotid pulse check is fundamentally unreliable during cardiac arrest:

• Healthcare providers incorrectly identify pulse presence or absence in up to 50% of cases, making manual palpation an unreliable diagnostic tool 1
• Even experienced providers take longer than 10 seconds to assess pulses, with average times of 15 seconds to detect a pulse and 30 seconds to confirm absence 1
• Accuracy is only 80% among healthcare professionals, with false positives occurring 14-24% of the time and false negatives 21-36% of the time 1

The Doppler Solution: Carotid Artery Assessment

Carotid Doppler ultrasound provides a superior alternative to manual pulse palpation during cardiac arrest:

Technical Performance

• Spectral Doppler of the common carotid artery can detect pulsatile flow in 100% of cases after brief training, with median assessment times of 23 seconds (32% achieved within 15 seconds) 2
• High interobserver reliability (Krippendorff's α = 0.874) for pulse interpretation, with 76% of assessments completed within 10 seconds 3
• Detects blood flow at systolic pressures as low as 19 mmHg, far below the threshold where manual palpation fails (typically <60 mmHg) 4

Clinical Applications During CPR

• Identifies ventricular fibrillation (21/21 events) and pulseless electrical activity (2/2 events) with 100% accuracy in animal models 4
• Provides real-time hemodynamic feedback during chest compressions, with measurable peak systolic velocities (median 67 cm/s) and end-diastolic velocities (median 18 cm/s) 5
• Can be performed continuously without interrupting chest compressions using hands-free systems, addressing the critical problem of compression interruptions 4

Integration with Current Guidelines

The 2025 Society of Critical Care Medicine guidelines support this approach:

• Point-of-care ultrasound during cardiac arrest may reduce pulse check duration and improve diagnostic accuracy 1
• Echocardiography is reasonable for pulse checks, diagnosing arrest etiology, and assessing chest compression adequacy when performed by proficient operators 1
• The intervention requires proper training, credentialing, and quality assurance processes 1

Why Vulvar/Labial Pulses Have No Role

There is zero evidence supporting vulvar or labial pulse assessment during cardiac arrest:

• All resuscitation guidelines specify central pulse assessment (carotid, femoral, or brachial in infants) 1
• Peripheral pulses are unreliable even in stable patients and become undetectable during low-flow states 1
• Vulvar/labial pulse assessment would require patient positioning incompatible with effective CPR and chest compressions 1

Practical Implementation Algorithm

For healthcare providers during cardiac arrest:

1. If no ultrasound available: Check carotid pulse manually for maximum 10 seconds only if organized rhythm appears on monitor 1

2. If ultrasound available and operator trained:

   • Place Doppler probe on carotid artery in transverse or longitudinal view 2, 5
   • Obtain spectral Doppler waveform (target <10 seconds) 3
   • Presence of pulsatile flow = pulse present; absence = continue CPR 4
   • Can be performed during brief pauses in compressions or continuously with hands-free systems 4

3. For lay rescuers: Never interrupt chest compressions for pulse checks—rely on signs of life (breathing, movement) 1

Critical Pitfalls to Avoid

• Do not use arterial relaxation pressure <20 mmHg as sole indicator to stop CPR—this is for monitoring CPR quality, not determining ROSC 1
• Do not delay CPR initiation while attempting Doppler assessment—chest compressions remain the priority 1
• Do not assess peripheral pulses (radial, pedal, vulvar, labial) during cardiac arrest—they provide no useful information and waste critical time 1
• Do not interrupt chest compressions for >10 seconds for any pulse check method 1