EMS World Instructional: How to Assess a Pedal Pulse

Produced in partnership with DistanceCME, this new series of how-to articles presents step-by-step details on performing EMS assessments, interventions and skills. Visit www.distancecme.com. Have an EMS skill you’d like to see explained in this column? Contact editor@emsworld.com

The Pedal Pulse

Dreaded by many, found by even less. This finicky pulse point, also known as the dorsalis pedis artery, is the first topic in this series.

Anatomy of a Pedal Pulse

Found on the dorsal aspect of the foot, the dorsalis pedis artery begins on the anterior aspect of the ankle joint and ends just before the proximal aspect of the first intermetatarsal space (between your big toe and your second toe).

Being a peripheral artery, the dorsalis pedis is responsible for supplying your foot with blood. Though not the most popular choice for paramedics, this artery plays an important role in helping to assess peripheral circulation.

Landmarking

This anterior-lying artery is the most distal pulse point that a paramedic assesses. Despite its location, close to the top layer of skin, the dorsalis pedis artery can be very difficult to locate.

When assessing any pulse, paramedics are encouraged to use their index and middle finger. The thumb has always been discouraged as an assessment tool as it has its own artery that runs down the center, resulting in a pulse presence that can be confused for the patient’s pulse.

Unlike the carotid, which is larger and considerably closer to the heart, the pedal pulse does not require a firm pressure to locate. In fact, the harder you push, the easier it is to miss. Use of a lighter touch might be the difference between locating and not locating the pedal pulse.

Why we Check for a Pedal Pulse

Paramedics generally agree that taking off a patient’s sock is a relatively “rookie move.” However, there are times when an assessment of the pedal pulse is a necessity. Here are a few.

Trauma:

Any trauma that results in injury to a lower limb should warrant a circulation check. When splinting a suspected fracture or when bandaging a hemorrhage, a pre- and post-circulation check should be performed.

The presence or absence of a pedal pulse alongside complaints of deficits should raise a high index of suspicion. Once found, the pedal pulse should be marked as a reference point for reassessments and for hospital staff.

Deficit complaints:

Any time a patient remarks that they are experiencing numbness or tingling, it would be wise to check circulation of that limb. Though not common without some type of associated trauma or comorbidity, such as diabetes, the absence of a pedal pulse alongside complaints of pain warrants further investigation.

Inability to ambulate:

If a patient is unable (not unwilling) to ambulate and has associated limb complaints, it would be worthwhile to assess circulation. Any spontaneous cessation of ambulation without trauma should raise a high index of suspicion.

Conditions That Complicate the Assessment of a Pedal Pulse

Peripheral Edema:

Any degree of peripheral edema increases the difficulty of locating a pedal pulse. As we know in medicine, water is not gravity-friendly and often collects in the limbs, resulting in bilateral edema that can be very painful.

Not only does increased swelling make it difficult to locate a pedal pulse, but the patient may have a very low pain tolerance toward your probing, as their skin is stretching (which can result in “seeping”—serous fluid exits the top layer of skin, with or without the presence of injury.)

Trauma:

As mentioned earlier, any type of trauma to a dependent limb can complicate the assessment of a pedal pulse. Due diligence should be performed when assessing circulation in the case of a traumatic leg injury.

Hypothermia:

When the body shunts blood to the core, peripheral circulation is affected. Pulses might be faint or absent depending on the length of time and temperature exposure.

Shock:

Any type of shock that affects central circulation brings the potential for weak or absent peripheral pulses. This includes mechanical (cardiogenic), hypovolemic, neurogenic (spinal), and systemic shocks (anaphylactic and septic).

What to do if you Cannot Find the Pedal Pulse

Fortunately, there are other techniques besides pedal pulses to determine peripheral circulation.

Sight: How does the limb present? Is it blue, pale, mottled, or normal in color? Is it attached or partially amputated? Is it in normal alignment, or does it look out of alignment?

Touch: How does the foot feel? Is it cold or warm? When you press down does the skin blanch (cap refill assessment) and immediately return to normal? Or is there a delay to return of normal coloring in the formally blanched area?

A delayed cap fill can indicate perfusion concerns and should be used in conjunction with a thorough patient exam and history. When assessing cap refill on a foot, you can use the nail beds or heel. However, a cap refill can be used on all aspects of the foot.

Listen: Listen to what your patient is saying about their foot. Is it tingling? Burning? Numb? Pins and needles? All of these complaints indicate a circulation check (yes, that means the sock has to come off).

Smarter, Not Harder

A thorough patient assessment and gathering of history helps determine a proper treatment plan. This involves any type of medical intervention, immobilization techniques, and method of extrication.

When assessments are performed correctly, we learn how to work smarter, not harder. After all, no paramedic likes it when the triage nurse asks a question we don’t have an answer to, because our assessments fell short. Stay safe out there!

Leah Sobon is a freelance writer and paramedic at the Region of Peel, Ontario, Canada.