Which artery pulse site is most commonly used to measure the blood pressure?

In each issue, the paramedic education team at Edge Hill University focuses on the clinical skills carried out by paramedics on the frontline, highlighting the importance of these skills and how to perform them. In this month's instalment, Andrew Kirk discusses common pulse sites and correct technique for obtaining a patient's pulse

Inhaltsverzeichnis Show

Learning Points
Pulse locations
Indications
The procedure
Interpretation
Volume and character/waveform
What site of pulse is most commonly taken?
Which pulse site is commonly used for obtaining a blood pressure and is located inside the patient's elbow or Antecubital space?
What are the sites for assessing the pulse and blood pressure?

Andrew Kirk

Pulse measurement is a key part of the assessment of a person's cardiovascular status and one of the primary vital signs assessed and recorded for every patient. Valuable information can be gained from the manual measurement of the pulse, which can be palpated at numerous sites across the body. It is therefore important to re-visit this key feature of patient assessment to ensure best practice is maintained.

This article will focus on explaining what a pulse is, the common pulse sites and correct technique in obtaining a pulse. Some, but not all, common interpretations and abnormalities will be discussed; however, these will not be explored in depth.

Learning Points

Pulse measurement is a key indicator of cardiovascular status and any subsequent improvement or deterioration in patient condition
Manual pulse measurement is a key baseline observation
Best practice technique can be ensured through the use of appropriate sites to assess the rate, rhythm, volume and character of the pulse

When the heart contracts and blood is ejected from the left ventricle, a pressure wave is generated and transmitted into the aorta and arterial tree. The flexible and elastic nature of artery walls enables this pulse wave transmission (Rawlings-Anderson and Hunter, 2008: Marieb and Hoehn, 2013). At certain points in the body, where arteries are either superficial or pass over a bone, these pulsations can be felt (Dougherty and Lister, 2015). In a healthy individual, the pulse rate represents the heart rate; however, there are circumstances whereby differences can occur such as with peripheral vascular disease or an acute arterial occlusion (Grossman and Porth, 2014; Waugh and Grant, 2018). If a peripheral artery is narrowed, damaged, occluded or diseased, the distal pulse may not represent the heart rate as a result of impaired blood supply. It is therefore important to check bilateral pulses to check for consistency (Gregory and Mursell, 2010). Manual assessment of the pulse is considered best practice as the clinician can assess for the rate, rhythm, volume and character.

Pulse locations

The most common and convenient site for pulse measurement is the radial artery due to the ease of access at the wrist and the rare requirement to remove clothing. Pulse rate and rhythm can be assessed at the radial artery, but because of its distal proximity to the heart, it is unsuitable to assess for volume or character (Docherty and Coote, 2006). The brachial, femoral and carotid pulse locations should be used to assess for volume and character as a result of their closer proximity to the heart, with the carotid artery being the preferred site. A full peripheral vascular examination should include assessment of all peripheral pulses. Pulse sites include the following:

Radial: Located at the wrist, lateral to the flexor carpi radialis tendon. This is the most common site for pulse measurement (Bickley, 2017)
Brachial: Located in the ante-cubital fossa, medial to the bicep tendon (Gregory and Mursell, 2010). This is a common site for blood pressure measurement. It is also used for pulse measurement in infants and children
Carotid: Located lateral to the larynx and anterior to the sternocleidomastoid muscle, this site should be palpated gently; furthermore, simultaneous bilateral pulses should never be palpated (Gregory and Mursell, 2010; Innes et al, 2018). The carotid artery supplies blood and oxygen to the brain, so light palpation is essential to prevent a reduction of blood flow to the brain (Alexis, 2010). This is especially important in patients with arteriosclerosis, particularly older patients. Excess pressure should be avoided to minimise the risk of stimulating baroreceptors located in the carotid arteries which can cause reflex bradycardia and syncope (Docherty and Coote, 2006). Patients should therefore be laid down when palpating the carotid artery
Femoral: Located over the superior pubic ramus, midway between the anterior superior iliac spine and the pubic tubercle, assessment of character and volume can be undertaken at the femoral site and is just as reliable as the carotid pulse (Docherty and Coote, 2006; Thomas and Monaghan, 2014). To obtain the femoral pulse, the patient should be laid flat and requires clothing removal; the clinician should therefore ensure consent is gained and dignity is respected accordingly
Popliteal: Located in the posterior popliteal fossa, this pulse site can be difficult to find. With the patient lying flat and the knee slightly flexed, press into the popliteal fossa. More pressure than expected is sometimes required to palpate this pulse (Thomas and Monaghan, 2014)
Posterior tibialis: Located at the posterior and inferior aspect of the medial malleolus of the tibia (Thomas and Monaghan, 2014)
Dorsalis pedis: Located on the superior aspect of the foot over the midtarsal bones, the pulses of the foot can be used to assess the peripheral vascular system and in cases of lower limb trauma.
Temporal: A pulse site less frequently used is the temporal pulse. This pulse is located lateral to the orbital socket of the eye, where the temporal artery passes over the temporal bone (Alexis, 2010).

Indications

Indications for pulse measurement are:

As a baseline cardiovascular assessment of the patient (Rawlings-Anderson and Hunter, 2008; Alexis, 2010)
As part of overall baseline observations of the patient
To monitor cardiovascular changes (Marieb and Hoehn, 2013)
To assess the general health and wellbeing of the patient (Alexis, 2010)
To assess for improvement or deterioration in the patient's condition (Alexis, 2010).

The procedure

The following is the generic procedure; differences with individual pulse sites are mentioned earlier within this article:

Cleanse and dry hands in accordance with local infection control requirements
Explain the procedure to the patient and gain consent (Health and Care Professions Council (HCPC), 2014)
Ensure the patient is comfortable and relaxed. Ideally, the patient should have rested for 20 minutes, and caffeine intake minimised prior to pulse measurement (Docherty and Coote, 2006; Dougherty and Lister, 2015); however, this can be difficult to ascertain in the out-of-hospital environment. Subsequent pulse measurements should occur in the same conditions to ensure consistency. Any differences or activity should be noted
Gently palpate the pulse using your first, second and third fingers, laying them across the pulse site along the line of the artery
Press gently to palpate the pulse
Best practice and the most accurate method is to palpate and count the pulse for 60 seconds (Docherty and Coote, 2006; Rawlings-Anderson and Hunter, 2008; Alexis, 2010).
- If the pulse is regular, and the patient healthy, then subsequent pulses can be taken for 30 seconds and doubled
- Variation in the literature states that a regular pulse rate can be counted for 15 seconds and multiplied by 4 (Caroline, 2014; Innes et al, 2018), with an irregular pulse counted for 30 seconds and doubled (Julian et al, 2004).
Record the findings in the appropriate documentation, noting the rate, rhythm and skin condition (e.g. cold to touch/clammy) (Rawlings-Anderson and Hunter, 2008).
Thank the patient and discuss your findings
Cleanse and dry hands.

Interpretation

Rate

The average pulse rate in a healthy adult is between 60–100 beats per minute (bpm) (Helbock and Jerin, 2011). Pulse rates can differ depending on age (Table 1), physical fitness and pre-existing medical conditions.

Table 1.

Normal heart rates

Age	Heart rate
<1 year	110–160 bpm
1–2 years	100–150 bpm
2–5 years	95–140 bpm
5–11 years	80–120 bpm
>12 years	60–100 bpm

Source: Advanced Life Support Group, 2012; JRCALC, 2016

A pulse rate less than 60 bpm is termed a bradycardia; however, this may be normal for a healthy athletic adult. Conversely, a patient who has a chronic cardiac condition may have a resting pulse rate of 65 bpm and this may be slow for them, resulting in insufficient perfusion. There are various causes of bradycardia including hypothermia, certain medications (e.g. beta-blockers) or excess vagal tone.

A pulse greater than 100 bpm is called a tachycardia, with many causes including exercise, fever, anxiety, hypovolaemia and hypoxia (Innes et al, 2018). A resting heart rate consistently over 120 bpm indicates a form of arrhythmia (Julian et al, 2004). The pulse rate may vary with posture. For example, for a healthy male lying down, the pulse rate would be 66 bpm. Sat up, the pulse rate will be 70 bpm; and stood up, 80 bpm. This is because of the extra pressure required to eject blood from the left ventricle and changes in peripheral vascular resistance to maintain effective cardiac output (Marieb and Hoehn, 2013). It is therefore important to measure a person's pulse rate in the same position, recording any changes accordingly.

Rhythm

The normal pulse rate should be regular. However, in individuals under 40 years of age, sinus arrhythmia may occur where the pulse rate quickens with inspiration and decreases with expiration (Rawlings-Anderson and Hunter, 2008; Innes et al, 2018). The pulse will be either regular or irregular; however, there are variations in irregular rhythms. The pulse can be deemed regularly irregular; for example, every 3rd or 4th beat consistently dropped owing to a second degree heart block. Regular ectopic beats may result in a regularly irregular pulse. This can be difficult to palpate and is much clearer to establish on a cardiac monitor (Thomas and Monaghan, 2014). Irregularly irregular rhythms occur where there is no set pattern such as in atrial fibrillation (Julian et al, 2004).

Volume and character/waveform

Pulse volume is also referred to as the amplitude (Gregory and Mursell, 2010). The volume/strength of the pulse can be described as bounding, weak or thready (Helbock and Jerin, 2011). Each ventricular contraction ejects between 60–80 mls of blood, also known as the stroke volume (Waugh and Grant, 2018). The more central arteries are most suitable for assessing pulse volume (Innes et al, 2018).

A reduced stroke volume will cause a reduction in pulse volume and can be caused by hypovolaemia and left ventricular failure, resulting in a weak or thready pulse (Innes et al, 2018). Estimating the blood pressure through pulse measurement is unreliable and inaccurate; however, it can be an indicator of organ perfusion if a radial pulse is present (JRCALC, 2017). Subsequently, an increased stroke volume results in an increased pulse volume and can be caused by physiological (exercise, pregnancy) and pathological factors (hypertension, thyrotoxicosis, fever, anaemia). This may be felt as a bounding pulse. The waveform/character of the pulse reflects the shape of the pulsation (Innes et al, 2018). This can be difficult to palpate initially, with practise and experience required to determine specific differences.

Conditions associated with pulses include the following:

Pulsus alternans: A beat-to-beat variation in pulse volume, which can be indicative of left ventricular failure (Thomas and Monaghan, 2014)
Pulsus paradoxus: A significant drop in pulse volume on inspiration caused by obstructive airway disease (including acute-severe asthma) or cardiac tamponade (Thomas and Monaghan, 2014). Pulse volume normally drops during inspiration owing to changes in intra-thoracic pressure; however, an excessive drop in the conditions as described is pulsus paradoxus
Collapsing pulse: Also known as a waterhammer pulse. The radial or brachial pulse is palpated and the arm raised vertically. With aortic regurgitation, a collapsing pulse is felt whereby after the initial pulsation, there is a rapid collapsing and drop of the pulse (Julian et al, 2004).
Pulsus bisferiens: A pulse of large or moderate volume where a double beat can be felt, suggestive of aortic stenosis and regurgitation combined (Julian et al, 2004; Thomas and Monaghan, 2014)
Pulsus bigeminy: A group of two heartbeats separated by a long pause; can be caused by premature ventricular contractions (Alexis, 2010)
Absence of a distal pulse can indicate arterial narrowing or occlusion and peripheral vascular disease
Radial-radial delay: Bilateral pulses should be synchronous; however, any condition that affects blood flow can result in asynchronous pulses. Coarctation (narrowing of the aorta) and aortic arch aneurysm can present as radial-radial delay
Radial-femoral delay: The radial and femoral arteries are normally synchronous; again, any condition affecting the peripheral blood flow can lead to asynchronous pulses (Innes et al, 2018).

Conclusion

Pulse measurement is an important assessment to determine the cardiovascular status of a patient and to provide a baseline observation on initial examination. Pulse measurement should not be used in isolation, but alongside other observations and assessments to provide a global picture of the patient's presenting condition. Review of best practice is important in order to maintain accuracy in undertaking clinical procedures to optimise patient care.

What site of pulse is most commonly taken?

The radial artery is one of two arteries in the upper arm that supply blood to the hand. It's commonly used as a quick measure of heart rate. When you're checking a client's pulse, you'll likely use your index finger and middle finger to do so — one on either side of the radial artery.

Which pulse site is commonly used for obtaining a blood pressure and is located inside the patient's elbow or Antecubital space?

The brachial pulse is palpated just above the angle of the elbow (the "antecubital fossa").

What are the sites for assessing the pulse and blood pressure?

The most common sites of measuring the peripheral pulses are the radial pulse, ulnar pulse, brachial pulse in the upper extremity, and the posterior tibialis or the dorsalis pedis pulse as well as the femoral pulse in the lower extremity. Clinicians measure the carotid pulse in the neck.