Anatomy of Foot Circulation

Pulse Assessment

• Two pulse sites used to determine circulation of the foot: posterior tibial and dorsalis pedis
• Posterior tibial pulse is located on the medial surface of the ankle, where the posterior tibial artery passes behind the medial malleolus
• Dorsalis pedis pulse is located on the foot, over the bones of the foot, on an imaginary line drawn from the middle of the ankle to the space between the big and second toes

Assessing the Pulse

• Pulse is commonly assessed by palpation (feeling) or auscultation (hearing)
• Middle three fingertips are used for palpating all pulse sites, applying moderate pressure (except apical pulse)
• Stethoscope is used for apical pulses
• Doppler Ultrasound Stethoscope (DUS) is used for pulses that are difficult to assess

Factors to Consider When Assessing the Pulse

• Medications that affect heart rate
• Patient's resting heart rate (e.g., physically fit athlete will have a resting heart rate below 60 beats/min)
• Position of patient (e.g., sitting position can affect heart rate)
• Baseline data about the normal heart rate

What to Obtain When Assessing the Pulse

• Rate
• Rhythm
• Volume
• Arterial wall elasticity
• Presence or absence of bilateral equality

Abnormal Pulse

• Tachycardia: excessively fast heart rate, over 100 beats/min in an adult
• Bradycardia: heart rate of less than 60 beats/min in an adult
• Dysrhythmia/arrhythmia: pulse with an irregular rhythm

Pulse Volume

• Refers to the force of blood with each beat
• Can range from absent to bounding
• A normal pulse can be felt with moderate pressure of the fingers and can be obliterated with greater pressure

Apical Pulse Assessment

• Purposes: obtain heart rate of an adult with irregular peripheral pulse or unavailable, monitor patient with cardiovascular, pulmonary, or renal diseases, and administer medications that affect heart rate
• Location: palpate the angle of Louis (angle between the manubrium and the body of the sternum) or the fifth intercostal space towards the medial to mid-clavicle line

Respiration

• Respiration: act of breathing
• Inhalation/inspiration: intake of air into the lungs
• Exhalation/expiration: breathing out or movement of gases from the lungs to the atmosphere
• Ventilation: movement of air in and out of the lungs

Types of Breathing

• Costal (thoracic) breathing: normal
• Other types of breathing: in response to lowered blood pressure or increased metabolic rate

Factors Affecting the Pulse Rate

• Medications: some decrease pulse rate, while others increase it
• Hypovolemia/dehydration: loss of blood from the vascular system increases pulse rate
• Stress: sympathetic nervous stimulation increases heart rate and force
• Position: sitting or standing can affect heart rate
• Pathology: certain diseases can alter resting pulse rate

Pulse Sites

• Temporal pulse: located on the temporal bone of the head, used when radial pulse is not accessible
• Carotid pulse: located at the side of the neck, used during cardiac arrest/shock in adults
• Apical pulse: located at the apex of the heart, used for infants and children up to 3 years old
• Brachial pulse: located at the inner aspect of the bicep muscles of the arms, used to measure blood pressure
• Radial pulse: located on the thumb side of the inner aspect of the wrist, readily accessible
• Femoral pulse: located alongside the inguinal ligament, used in cardiac arrest/shock
• Popliteal pulse: located behind the knee, used to determine circulation to the lower leg

Assessment of Patients

• Pulse: a wave of blood created by contraction of the left ventricle of the heart
• Pulse wave represents the stroke volume output or the amount of blood that enters the arteries with each ventricular contraction
• Compliance of the arteries: ability to contract and expand

Factors Affecting the Pulse

• Age: pulse rate gradually decreases with age
• Sex: average male pulse rate is slightly lower than the female pulse rate after puberty
• Exercise: pulse rate normally increases with activity
• Fever: pulse rate increases