OSCE Steps for Radial Pulse Examination
The radial pulse should be examined systematically using proper positioning, palpation technique at the lateral flexor surface of the wrist, and assessment of rate, rhythm, character, and volume over a minimum of 15-30 seconds.
Patient Preparation and Positioning
- Position the patient comfortably with their arm relaxed and supported at heart level (midsternum), with the wrist slightly extended and palm facing upward 1
- Ensure the patient is seated with back supported and feet on the ground, having rested for 3-5 minutes prior to examination 1
- Instruct the patient to avoid smoking, caffeine, and exercise for at least 30 minutes before examination 1
- Both examiner and patient should refrain from talking during the examination period 1
Anatomical Localization
- Locate the radial artery on the lateral (thumb side) flexor surface of the wrist, where it lies superficially just over the radius bone 1, 2
- Identify the anatomical landmark at the distal wrist crease, with the pulse palpable between the distal wrist crease and the prominent bone (styloid process) 3
- The radial pulse is positioned laterally compared to the ulnar pulse, which is palpable on the medial flexor surface 2
Palpation Technique
- Use the pads of your index and middle fingers (some practitioners include the ring finger) to palpate the artery, avoiding use of your thumb which has its own pulse 3
- Apply gentle to moderate pressure progressively until the pulse is optimally felt—excessive pressure will obliterate the pulse 4, 5
- Palpate at multiple depths if needed, as the radial artery can be examined at different layers to achieve optimal pulse waveform 5
- If the radial pulse is difficult to locate, consider using ultrasound guidance or palpating the digital artery at the proximal phalanx of the index finger as an alternative 1, 6
Assessment Parameters
Rate
- Count the pulse for a full 60 seconds for accuracy, or minimum 30 seconds and multiply by two if rhythm is regular 7
- Normal adult resting heart rate ranges from 60-100 beats per minute 7
Rhythm
- Assess for regularity by noting the intervals between beats—irregular rhythms require full 60-second counting 7
- Identify any pattern to irregularity (regularly irregular vs. irregularly irregular) 7
Character and Volume
- Assess pulse character as normal, weak, or bounding 7
- A weak radial pulse character correlates with lower systolic blood pressure (mean 26 mmHg lower) and significantly increased mortality in trauma patients (odds ratio 15.2) 7
- Weak pulse suggests systolic blood pressure may be below 100 mmHg and warrants immediate further assessment 7
- Evaluate pulse volume by assessing the strength and amplitude of the arterial pulsation 4
Bilateral Comparison
- Always compare both radial pulses simultaneously or sequentially 1
- Measure bilateral upper extremity blood pressures to determine suitability and identify any asymmetry suggesting arterial pathology 1
- Differential arm findings may indicate venous obstruction or arterial stenosis 1
Special Considerations and Pitfalls
- If radial pulse is absent, this represents an absolute contraindication to radial artery cannulation and requires investigation for arterial occlusion 1, 8
- Avoid examining through clothing—remove any garments at the examination site 1
- In patients with splints, casts, or swelling where radial pulse is inaccessible, digital artery palpation or pulse oximetry waveform can serve as alternatives 6
- Digital pulse palpation has high positive predictive value—when present, radial pulse can be assumed present 6
- Pulse oximetry waveform is more sensitive than pulse palpation and may detect perfusion before pulses become palpable 6
- Consider performing Allen's test if evaluating collateral circulation, though recent evidence suggests this is not necessary for most clinical scenarios as hand ischemia remains rare due to robust ulnar collateralization 1, 2