4-12. PULSE

The pulse is the vibration of each wave of blood going through the arteries as the heart beats. The pulse rate is usually equal to heart rate, but may be lower if there is an obstruction of the artery or if the heart rhythm is weak or irregular. You can feel it by placing your fingers over one of the large arteries that lie close to the skin, especially if the artery runs across a bone and has very little soft tissue around it.

(1) Radial.

(2) Temporal.

(3) Carotid.

(4) Apical (listening to the heart directly).

(5) Brachial.

(6) Femoral.

(7) Popliteal.

(8) Pedal (dorsalis pedis)

b. The rate that the heart beats varies with the patient's age, size, and weight. The normal rate for an adult is 60 to 80 beats per minute. Women have a slightly higher average rate than men. The pulse of an infant ranges from 120 to 140 beats per minute. Rates for children vary according to the size and the age of the child.

c. Activity affects the pulse rate. Exercise or heavy physical work cause the heart to beat faster and the pulse rate to increase. Excitement, anger, and fear increase the rate. Some drugs, such as caffeine, may also increase the pulse rate. If the patient has a fever, the pulse rate increases in proportion to the body's temperature: the pulse rate goes up about 10 beats for every 1^ºF (0.56^ºC). These conditions cause a temporary increase in the heartbeat and pulse rate. The heartbeat and pulse rate that is consistently above normal may be a sign of heart disease, heart failure, hemorrhage, an overactive thyroid gland, or some other serious disturbance. The term for an abnormally rapid heartbeat is tachycardia. When the heartbeat is continuously slow, below 60 per minute, the condition is called bradycardia.

4-13. DESCRIBING THE PULSE

a. Pulse rate describes how often the heart beats.

b. Pulse volume describes the force with which the heart beats. The volume of the pulse varies with the volume of blood in the arteries, the strength of the heart contractions, and the elasticity of the blood vessels. A normal pulse can be felt with moderate pressure of the finger. When every beat is easily felt, the pulse is described as strong. When greater pressure exerted by the finger cannot blot out the pulse, it is called full or bounding. A pulse with little force is described as weak or thready.

c. Pulse rhythm is the spacing of the heartbeats. When the intervals between the beats are the same, the pulse is described as normal or regular. When the pulse skips a beat occasionally, it is described as intermittent or irregular. A pulse may be regular in rhythm but irregular in force, with every other beat being weak. To obtain an accurate assessment of the heart rate, the pulse is counted by listening directly to the heart (apical pulse).

4-14. FACTORS, WHICH AFFECT THE PULSE RATE

The pulse rate is an indicator of how fast the heart beats. The pulse rate is affected by several factors.

a. Age. A normal pulse for infants range from 90 to 170 and the rate gradually decreases up to age 14 when it is equal to the normal adult pulse rate of 60 to 100.

b. Body Build and Size. A short, fat person may have a higher rate than a tall, slender person.

c. Blood Pressure. As the blood pressure decreases, the pulse will frequently increase.

d. Medications. Stimulants will increase the pulse rate; depressants will decrease the pulse rate.

e. Exercise and Muscular Activity. An increase in pulse rate will occur with increased activity to meet increased oxygen and nutrient demands. A regular aerobic exercise program can lower the resting pulse. A person, who exercises a great deal, such as an athlete, will develop bradycardia that is a normal, health condition. The body slows the heartbeat to compensate for the greater volume of blood pumped with each beat.

f. Food Intake. Digestion increases the pulse slightly.

g. Elevated Body Temperature. The pulse increases approximately 10 beats per minute for every 1 F (0.56^º C) increase in body temperature. These conditions cause a temporary increase in the heartbeat and pulse.

h. Emotional Status. Fear, anger, and anxiety will all increase the pulse rate.

i. Pain. When the patient is in pain, the pulse rate will increase.

4-15. MEASURING THE PULSE

a. Measuring a Radial Pulse.

(1) Wash your hands to prevent the spread of infection.

(2) Supporting the patient's arm and hand with the palm down, press the first, second, and third finger of your dominant hand gently against the radius bone until you feel the contraction and expansion of the artery with each heartbeat. Do not use your thumb; it has a strong pulse of its own and you may be counting your pulse.

(3) Count the pulsations for 30 seconds using a watch with a second hand or digital display to time yourself. Multiply the count by 2 to determine the rate for 1 minute. If the pulse is abnormal in any way, count for a full minute to get a more accurate reading.

(4) The pulse rate may also be determined by the electronic vital signs monitor (see figure 4-3).

(5) If there is any doubt about the rhythm or rate of the heart, take an apical pulse.

b. Measuring an Apical Pulse.

(1) Warm the stethoscope in your hands. A cold stethoscope may surprise the patient and alter the pulse rate.

(2) Place the stethoscope at the apex (pointed end) of the heart, in the left center of the chest, just below the nipple. The pulse can usually be heard best at the apex.

(3) Count the pulse for one full minute.

c. Measuring the Apical-Radial Pulse.

(1) If the apical-radial (A-R) pulse is ordered by the physician, two nurses carry out the procedure together.

(2) Using the same watch, one nurse counts the patient's apical pulse for 1 minute while the other nurse counts the radial pulse for 1 minute. One nurse gives the signal to start counting, and both start at the same time. The two figures are identified and charted (A-R pulse 76/72, for example). Normally, these two readings should be the same. If there is a difference, it is called the pulse deficit.

NOTE: An apical pulse will never be lower than the radial pulse.