In the Field
The radial pulse is the most useful piece of physical exam data you can collect in a tactical environment. You can feel it through gloves, in low light, behind cover, without exposing the patient. Whether it is present, how fast it is, and whether it is strong or weak tells you more about the patient's circulatory status than almost anything else available at the point of injury. When you do not have time, light, or space for a full assessment, the radial pulse is what you have.
Common Mistake
Skipping the radial pulse check in favor of waiting for a blood pressure measurement that is not feasible to obtain at the point of injury.
Technical Detail
The radial pulse is the palpable pulsation of the radial artery at the wrist, on the thumb side of the inner forearm. It is the most commonly assessed peripheral pulse in clinical and field medicine.
How to assess. Place the index and middle fingers (not the thumb, which has its own pulse) on the wrist on the thumb side, applying gentle pressure until the pulsation is felt. Note three things:
Presence or absence. Whether a pulse can be felt at all.
Rate. The number of beats per minute, typically counted over 15 seconds and multiplied by four, or over a longer interval for more accuracy.
Quality. Whether the pulse is strong (full, easily palpable) or weak (thready, difficult to feel).
What the radial pulse indicates. The radial pulse is one of the more peripheral pulses in the body. As perfusion fails, peripheral pulses are lost first while central pulses (carotid, femoral) remain. The radial pulse therefore serves as an early indicator of circulatory compromise.
Three findings carry significant prognostic weight in trauma:
Absent radial pulse. A radial pulse that cannot be palpated suggests a systolic blood pressure below approximately 80 to 90 mmHg. In a trauma patient with potential blood loss, this indicates significant hemorrhagic shock requiring immediate intervention.
Weak or thready radial pulse. A pulse that is present but difficult to feel suggests compensated shock with reduced stroke volume. The cardiovascular system is keeping up but is straining.
Rapid pulse rate. A radial pulse rate above approximately 100 beats per minute in an adult, particularly when combined with a weak quality, suggests compensatory tachycardia from blood loss. Rates above 120 in an adult patient are concerning.
Why it matters in tactical medicine. The radial pulse is reliably accessible in tactical conditions when other assessment methods are not:
Available through tactical gloves with practice.
Assessable in low light or zero-light conditions.
Does not require exposing the patient.
Does not require equipment.
Can be checked while the patient is in any position, including behind cover, on a stretcher, or in a vehicle.
In contrast, blood pressure measurement, pulse oximetry, ECG monitoring, capillary refill assessment, and skin color evaluation all require time, equipment, lighting, or patient exposure that may not be feasible at the point of injury. The radial pulse is the fallback indicator when those tools are not available.
When to use other pulses. If the radial pulse is absent or unreliable, more central pulses can be assessed:
Femoral pulse. Felt in the groin. Indicates a systolic pressure of approximately 60 to 70 mmHg or higher.
Carotid pulse. Felt in the neck. Indicates a systolic pressure of approximately 60 mmHg or higher.
A patient with a palpable carotid pulse but absent radial pulse is in significant shock and requires immediate intervention.
In MARCH and shock assessment. The radial pulse is a key data point in the C (Circulation) component of the MARCH algorithm and is the primary observable used in field shock assessment. See the Shock entry for detail on tactical shock assessment.
