PULSE

The pulse is a wave of blood created by contraction of the left ventricle of the heart. Generally, the pulse wave represents the stroke volume output or the amount of blood that enters the arteries with each ventricular contraction. Compliance of the arteries is their ability to contract and expand. When a person’s arteries lose their distensibility, as can happen with age, greater pressure is required to pump the blood into the arteries. 

Pulse rate: The number of pulsing sensations occurring in 60 seconds.

Cardiac output: This the volume of blood pumped by the heart within 60 seconds and it equals the product of HR and the ventricular SV. In an adult the heart normally pumps 5L of blood per minute.

When an adult is resting, the heart pumps about 5 liters of blood each minute. In a healthy person, the pulse reflects the heartbeat; that is, the pulse rate is the same as the rate of the ventricular contractions of the heart. However, in some types of cardiovascular disease, the heartbeat and pulse rates can differ. For example, a client’s heart may produce very weak or small pulse waves that are not detectable in a peripheral pulse far from the heart. In these instances, the nurse should assess the heartbeat and the peripheral pulse. 

A peripheral pulse is a pulse located away from the heart, for example, in the foot or wrist. The apical pulse, in contrast, is a central pulse; that is, it is located at the apex of the heart. It is also referred to as the point of maximal impulse (PMI).

FACTORS AFFECTING THE PULSE

The rate of the pulse is expressed in beats per minute (beats/min). A pulse rate varies according to a number of factors. The nurse should consider each of the following factors when assessing a client’s pulse:

• Age. As age increases, the pulse rate gradually decreases.

Variations in Pulse with Age:

                    Pulse Average                          Ranges

Newborn          130                                        80–180

1 year               120                                       80–140

5–8 years         100                                        75–120

10 years            70                                         50–90

Teen                  75                                         50–90

Adult                 80                                          60–100

• Sex. After puberty, the average male’s pulse rate is slightly lower than the female’s.
• Exercise. The pulse rate normally increases with activity. The rate of increase in the professional athlete is often less than in the average person because of greater cardiac size, strength, and efficiency.
• Fever. The pulse rate increases;

(a) in response to the lowered blood pressure that results from peripheral vasodilation associated with elevated body temperature and 

(b) because of the increased metabolic rate.

• Medications. Some medications decrease the pulse rate, and others increase it. For example, cardiotonics (e.g., digitalis preparations) decrease the heart rate, whereas epinephrine increases it.
• Hypovolemia/dehydration. Loss of blood from the vascular system increases the pulse rate. In adults, the loss of circulating volume results in an adjustment of the heart rate to increase blood pressure as the body compensates for the lost blood volume.
• Stress. In response to stress, sympathetic nervous stimulation increases the overall activity of the heart. Stress increases the rate as well as the force of the heartbeat. Fear and anxiety as well as the perception of severe pain stimulate the sympathetic system.
• Position. When a person is sitting or standing, blood usually pools in dependent vessels of the venous system. Pooling results in a transient decrease in the venous blood return to the heart and a subsequent reduction in blood pressure and increase in heart rate.
• Pathology. Certain diseases such as some heart conditions or those that impair oxygenation can alter the resting pulse rate.

Characteristics of the normal pulse which should be noted are:

1. The rate at which the heart beats

2. Rhythm; The pulse rhythm is the pattern of the beats and the intervals between the beats. Equal time elapses between beats of a normal pulse (The length of time between each beat should the same). Therefore, the Nurse\Midwife should note the regularity with which the heart beats occur. 

3. Volume or strength of the beat. It should require moderatepressure to obliterate the blood vessel.

4.Tension; The vessel should feel pliant and soft i.e. it should not feel hard and tortuous under the Nurse’s hand.

PULSE SITES

A pulse may be measured in nine sites: 

1. Temporal: Where the temporal artery passes over the temporal bone of the head. The site is superior (above) and lateral to (away from the midline of) the eye.

2. Carotid: It is located at the side of the neck where the carotid artery runs between the trachea and the sternocleidomastoid muscle.

NB: Never press both carotids at the same time because this can cause a reflex drop in blood pressure or pulse rate.

3. Apical: Located at the apex of the heart. In an adult, this is located on the left side of the chest, about 8 cm to the left of the sternum (breastbone) at the fifth intercostal space (area between the ribs). In older adults, the apex may be further left if conditions are present that have led to an enlarged heart. Before 4 years of age, the apex is left of the midclavicular line (MCL); between 4 and 6 years, it is at the MCL for a child 7 to 9 years of age, the apical pulse is located at the fourth or fifth intercostal space. 

4. Brachial: Located at the inner aspect of the biceps muscle of the arm or medially in the antecubital space. 

5. Radial: Located where the radial artery runs along the radial bone, on the thumb side of the inner aspect of the wrist. The radial site is most commonly used in adults. It is easily found in most people and readily accessible.

6. Femoral: Located where the femoral artery passes alongside the inguinal ligament. 

7. Popliteal: Located where the popliteal artery passes behind the knee. 

8. Posterior tibial: Located on the medial surface of the ankle where the posterior tibial artery passes behind the medial malleolus. 

9. Dorsalis pedis: Located where the dorsalis pedis artery passes 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. 

REASONS FOR USING SPECIFIC PULSE SITE

Radial: Readily accessible

Temporal: It is usually used when radial pulse is not accessible

Carotid: It is used during cardiac arrest/shock in adults, it can be used to determine circulation to the brain

Apical: It is routinely used for infants and children up to 3 years of age, also used to determine discrepancies with radial pulse and can be used in conjunction with some medications.

Brachial: It is used to measure blood pressure, used during cardiac arrest for infants.

Femoral: It is used in cases of cardiac arrest/shock and can be used to determine circulation to a leg

Popliteal: It is used to determine circulation to the lower leg

Posterior tibial: : It is used to determine circulation to the foot

Dorsalis pedis: It is used to determine circulation to the foot

ASSESSING THE PULSE

A pulse is commonly assessed by palpation (feeling) or auscultation (hearing). The middle three fingertips are used for palpating all pulse sites except the apex of the heart. A stethoscope is used for assessing apical pulses. A pulse is normally palpated by applying moderate pressure with the three middle fingers of the hand. The pads on the most distal aspects of the finger are the most sensitive areas for detecting a pulse. With excessive pressure, one can obliterate a pulse, whereas with too little pressure one may not be able to detect it. 

Before the nurse assesses the resting pulse, the client should assume a comfortable position. The nurse should also be aware of the following:

• Any medication that could affect the heart rate.
• Whether the client has been physically active. If so, wait 10 to 15 minutes until the client has rested and the pulse has slowed to its usual rate.
• Any baseline data about the normal heart rate for the client. For example, a physically fit athlete may have a resting heart rate below 60 beats/min.
• Whether the client should assume a particular position (e.g., sitting). In some clients, the rate changes with the position because of changes in blood flow volume and autonomic nervous system activity. When assessing the pulse, the nurse collects the following data: the rate, rhythm, volume, arterial wall elasticity, and presence or absence of bilateral equality.

Pulse volume, also called the pulse strength or amplitude, refers to the force of blood with each beat. Usually, the pulse volume is the same with each beat. It 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. A forceful or full blood volume that is obliterated only with difficulty is called a full or bounding pulse. A pulse that is readily obliterated with pressure from the fingers is referred to as weak, feeble, or thready. The elasticity of the arterial wall reflects its expansibility or its deformities. A healthy, normal artery feels straight, smooth, soft, and pliable. Older adults often have inelastic arteries that feel twisted (tortuous) and irregular on palpation. When assessing a peripheral pulse to determine the adequacy of blood flow to a particular area of the body (perfusion), the nurse should also assess the corresponding pulse on the other side of the body. The second assessment gives the nurse data with which to compare the pulses. For example, when assessing the blood flow to the right foot, the nurse assesses the right dorsalis pedis pulse and then the left dorsalis pedis pulse. If the client’s right and left pulses are the same volume and elasticity, the client’s dorsalis pedis pulses are bilaterally equal. The pulse rate does not need to be counted when assessing for perfusion and equality. When a peripheral pulse is located, it indicates that pulses more proximal to that location will also be present. For example, if the dorsalis pedis, the most distal pulse of the lower extremity, cannot be felt, the nurse next palpates for the posterior tibial pulse. If it is not felt, the popliteal pulse must be assessed. If the popliteal pulse is found, it is not necessary to assess the femoral pulse since it must also be present in order for the more distal pulse to exist.

ABNORMALITIES IN PULSE

Tachycardia is an abnormally elevated heart rate i.e an increase in heart rate above 100 beats/min in an adult. This is found in certain hearty diseases, in some anaemias, and in thyrotoxicosis. Tachycardia may be continuous or paroxysmal i.e. occurring at irregular periods and for varying lengths of time.

Bradycardia is an abnormally slow heart rate, i.e. heart rate in an adult of less than 60 beats/min. It occurs in most cases of head injury, cerebral tumour and in diseases of the liver associated with jaundice etc.

Dysrhythmia or Arrhythmia is a pulse with an irregular rhythm. It may consist of random, irregular beats or a predictable pattern of irregular beats. When a dysrhythmia is detected, the apical pulse should be assessed. An electrocardiogram (ECG) is necessary to define the dysrhythmia further. 

RESPIRATIONS

Respiration is the act of breathing i.e. Inhalation and Expiration.

Inhalation or Inspiration refers to the intake of air into the lungs and exhalation or expiration refers to breathing out or the movement of gases from the lungs to the atmosphere. The apparent movement of the chest wall (the rise and fall) denotes respiration and must be counted and recorded by the midwife.

Ventilation is also used to refer to the movement of air in and out of the lungs. There are basically two types of breathing: costal (thoracic) breathing and diaphragmatic (abdominal) breathing. Costal breathing involves the external intercostal muscles and other accessory muscles, such as the sternocleidomastoid muscles. It can be observed by the movement of the chest upward and outward. By contrast, diaphragmatic breathing involves the contraction and relaxation of the diaphragm, and it is observed by the movement of the abdomen, which occurs as a result of the diaphragm’s contraction and downward movement. 

Assessing Respirations

Resting respirations should be assessed when the client is relaxed because exercise affects respirations, increasing their rate and depth. Anxiety is likely to affect respiratory rate and depth as well. Respirations may also need to be assessed after exercise to identify the client’s tolerance to activity. Before assessing a client’s respirations, a nurse should be aware of the following:

• The client’s normal breathing pattern
• The influence of the client’s health problems on respirations
• Any medications or therapies that might affect respirations
• The relationship of the client’s respirations to cardiovascular function. The rate, depth, rhythm, quality, and effectiveness of respirations should be assessed. The respiratory rate is normally described in breaths per minute. Breathing that is normal in rate and depth is called eupnea.

FACTORS AFFECTING RESPIRATIONS

Several factors influence respiratory rate. They are:

• Exercise: It increases metabolism increases thereby increasing the rate and depth to meet the need of the body for additional oxygen and to rid the body of CO2.
• Acute Pain alters rate and rhythm of respirations; breathing becomes shallow. Patient inhibits or splints chest wall movement when pain is in area of chest or abdomen.
• Anxiety/ stress (readies the body for “fight or flight”); Increases respiration rate and depth as a result of sympathetic stimulation.
• Smoking: Chronic smoking changes pulmonary airways, resulting in increased rate of respirations at rest when not smoking.
• Body Position: A straight, erect posture promotes full chest expansion. A stooped or slumped position impairs ventilatorymovement while lying flat prevents full chest expansion. People in a supine position experience two physiological processes that suppress respiration: an increase in the volume of blood inside the thoracic cavity and compression of the chest. Consequently, clients lying on their back have poorer lung aeration, which predisposes them to the stasis of fluids and subsequent infection.
• Medications: Opioid analgesics, general anesthetics, and sedative hypnotics depress rate and depth. Amphetamines and cocaine sometimes increase rate and depth. Bronchodilators slow rate by causing airway dilation.
• Neurological Injury: Injury to brainstem impairs respiratory center and inhibits respiratory rate and rhythm.
• Hemoglobin Function: Decreased hemoglobin levels (anemia) reduce oxygen-carrying capacity of the blood, which increases respiratory rate. Increased altitude lowers amount of saturated hemoglobin, which increases respiratory rate and depth. Abnormal blood cell function (e.g., sickle cell disease) reduces ability of hemoglobin to carry oxygen, which increases respiratory rate and depth.
• Environmental temperature: Increased environmental temperature increases respiratory rate while decrease in environmental temperature decreases it.
• Age/Sex: Respiratory rate is lower in adult than in children and it is usually more slightly higher in women than in men.

Age                     Respirations Average (and Ranges) 

Newborn                          35                  30–60 

1 year                               30                   20–40 

5–8 years                         20                   15–25 

10 years                           19                   15–25 

Teen                                18                   15–20 

Adult                               16                   12–20 

Older adult                      16                    15–20

ALTERATIONS IN BREATHING PATTERN

Bradypnea: Rate of breathing is regular but abnormally slow (less than 12 breaths/min).

Tachypnea: Rate of breathing is regular but abnormally rapidwith shallow breath (greater than 20 breaths/min).

Dyspnea: Difficult and labored breathing during which the individual has a persistent, unsatisfied need for air and feels distressed

Apnea: Respirations cease for several seconds. Persistent cessation results in respiratory arrest. Hyperventilation;Overexpansion of the lungs characterized by rapid and deep breaths. Hypocarbia sometimes occurs.

Hypoventilation: Underexpansion of the lungs, characterized by shallow respirations. Respiratory rate is abnormally low, and depth of ventilation is depressed. Hypercarbia sometimes occurs.

Cheyne-Stokes Respiration: Respiratory rate and depth are irregular, characterized by alternating periods of apnea and hyperventilation. Respiratory cycle begins with slow, shallow breaths that gradually increase to abnormal rate and depth. The pattern reverses; breathing slows and becomes shallow, concluding as apnea before respiration resumes.

Kussmaul’s respiration: Respirations are abnormally deep, regular, and increased in rate. 

Biot’s respiration: Respirations are abnormally shallow for two to three breaths, followed by irregular period of apnea.

Orthopnea: Ability to breathe only in upright sitting or standing positions

BREATH SOUNDS

They are usually audible without amplification.

• Stridor—a shrill, harsh sound heard during inspiration with laryngeal obstruction
• Stertor—snoring or sonorous respiration, usually due to a partial obstruction of the upper airway
• Wheeze—continuous, high-pitched musical squeak or whistling sound occurring on expiration and sometimes on inspiration when air moves through a narrowed or partially obstructed airway
• Bubbling—gurgling sounds heard as air passes through moist secretions in the respiratory tract

CHEST MOVEMENTS

• Intercostal retraction—indrawing between the ribs
• Substernal retraction—indrawing beneath the breastbone
• Suprasternal retraction—indrawing above the clavicles

SECRETIONS AND COUGHING

• Hemoptysis—the presence of blood in the sputum
• Productive cough—a cough accompanied by expectorated secretions
• Nonproductive cough—a dry, harsh cough without secretion

 

BLOOD PRESSURE

Arterial blood pressure is a measure of the pressure exerted by the blood as it flows through the arteries. Because the blood moves in waves, there are two blood pressure measurements. The systolic pressure is the pressure of the blood as a result of contraction of the ventricles, that is, the pressure of the height of the blood wave. The diastolic pressure is the pressure when the ventricles are at rest. Diastolic pressure, then, is the lower pressure, present at all times within the arteries. The difference between the diastolic and the systolic pressures is called the pulse pressure. 

A normal pulse pressure is about 40 mmHg but can be as high as 100 mmHg during exercise. Blood pressure is measured in millimeters of mercury (mmHg) and recorded as a fraction: systolic pressure over the diastolic pressure. A typical blood pressure for a healthy adult is 120/80 mmHg (pulse pressure of 40). Because blood pressure can vary considerably among individuals, it is important for the nurse to know a specific client’s baseline blood pressure. For example, if a client’s usual blood pressure is 180/100 mmHg, and it is assessed following surgery to be 120/80 mmHg, this significant drop in pressure may indicate complications and must be reported to the primary care provider. 

DETERMINANTS OF BLOOD PRESSURE ARTERIAL BLOOD PRESSURE

Pumping action of the heart: When the pumping action of the heart is weak, less blood is pumped into arteries (lower cardiac output), and the blood pressure decreases. When the heart’s pumping action is strong and the volume of blood pumped into the circulation increases (higher cardiac output), the blood pressure increases.

Peripheral vascular resistance: This is the resistance supplied by the blood vessels through which the blood flows. Peripheral resistance can increase blood pressure. The diastolic pressure especially is affected. Some factors that create resistance in the arterial system are the capacity of the arterioles and capillaries, the compliance of the arteries, and the viscosity of the blood. The internal diameter or capacity of the arterioles and the capillaries determines in great part the peripheral resistance to the blood in the body. The smaller the space within a vessel, the greater the resistance. Normally, the arterioles are in a state of partial constriction. Increased vasoconstriction, such as occurs with smoking, raises the blood pressure, whereas decreased vasoconstriction lowers the blood pressure. If the elastic and muscular tissues of the arteries are replaced with fibrous tissue, the arteries lose much of their ability to constrict and dilate. This condition, most common in middle-aged and older adults, is known as arteriosclerosis.

Blood volume: When the blood volume decreases (for example, as a result of a hemorrhage or dehydration), the blood pressure decreases because of decreased fluid in the arteries. Conversely, when the volume increases (for example, as a result of a rapid intravenous infusion), the blood pressure increases because of the greater fluid volume within the circulatory system.

Blood viscosity: Blood pressure is higher when the blood is highly viscous (thick), that is, when the proportion of red blood cells to the blood plasma is high. This proportion is referred to as the hematocrit. The viscosity increases markedly when the hematocrit is more than 60% to 65%.

FACTORS AFFECTING BLOOD PRESSURE

• Age: Newborns have a systolic pressure of about 75 mmHg. The pressure rises with age, reaching a peak at the onset of puberty, and then tends to decline somewhat. In older adults, elasticity of the arteries is decreased, the arteries are more rigid and less yielding to the pressure of the blood. This produces an elevated systolic pressure. Because the walls no longer retract as flexibly with decreased pressure, the diastolic pressure may also be high.
• Exercise: Physical activity increases the cardiac output and hence the blood pressure. For reliable assessment of resting blood pressure, wait 20 to 30 minutes following exercise.
• Stress: Stimulation of the sympathetic nervous system increases cardiac output and vasoconstriction of the arterioles, thus increasing the blood pressure reading; however, severe pain can decrease blood pressure greatly by inhibiting the vasomotor center and producing vasodilation.
• Race: African Americans older than 35 years tend to have higher blood pressures than European Americans of the same age although the exact reasons for these differences are unclear
• Sex: After puberty, females usually have lower blood pressures than males of the same age; this difference is thought to be due to hormonal variations. After menopause, women generally have higher blood pressures than before.
• Medications: Many medications, including caffeine, may increase or decrease the blood pressure.
• Obesity: Both childhood and adult obesity predispose to hypertension.
• Diurnal variations: Pressure is usually lowest early in the morning, when the metabolic rate is lowest, then rises throughout the day and peaks in the late afternoon or early evening.
• Medical conditions. Any condition affecting the cardiac output, blood volume, blood viscosity, and/or compliance of the arteries has a direct effect on the blood pressure.
• Temperature: Because of increased metabolic rate, fever can increase blood pressure. However, external heat causes vasodilation and decreased blood pressure. Cold causes vasoconstriction and elevates blood pressure.

ABNORMALITIES IN BLOOD PRESSURE

HYPERTENSION: A blood pressure that is persistently above normal is called hypertension. A single elevated blood pressure reading indicates the need for reassessment. Hypertension cannot be diagnosed unless an elevated blood pressure is found when measured twice at different times. It is usually asymptomatic and is often a contributing factor to myocardial infarctions (heart attacks). An elevated blood pressure of unknown cause is called primary hypertension.

An elevated blood pressure of known cause is called secondary hypertension. Hypertension is a widespread health problem. Individuals with diastolic blood pressures of 80 to 89 mmHg or systolic blood pressures of 120 to 139 mmHg should be considered prehypertensive and, without intervention, may develop cardiac disease. Hypertension is when either the systolic BP is higher than 140 mmHg or when the diastolic blood pressure (BP) is 90 mmHg or higher 

Factors associated with hypertension include thickening of the arterial walls, which reduces the size of the arterial lumen, and inelasticity of the arteries as well as such lifestyle factors as cigarette smoking, obesity, heavy alcohol consumption, lack of physical exercise, high blood cholesterol levels, and continued exposure to stress. 

HYPOTENSION: Hypotension is a blood pressure that is below normal, that is, a systolic reading consistently between 85 and 110 mmHg in an adult whose normal pressure is higher than this. Orthostatic hypotension is a blood pressure that decreases when the client sits or stands. It is usually the result of peripheral vasodilation in which blood leaves the central body organs, especially the brain, and moves to the periphery, often causing the person to feel faint.

Hypotension can also be caused by analgesics such as meperidine hydrochloride (Demerol), bleeding, severe burns, and dehydration. It is important to monitor hypotensive clients carefully to prevent falls.