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Chapter 5

Vital Signs

This chapter reviews three procedures and five skills: measuring body temperature, assessing radial pulse, assessing apical pulse, assessing radial-apical pulse, assessing respirations, assessing arterial blood pressure, assessing blood pressure electronically, and measuring oxygen saturation.

Vital Signs

Reveal changes in patient condition

Include temperature, pulse, blood pressure, respirations, oxygen saturation

Sometimes pain is included

Performed during routine physical assessment

Vital signs
Indicate whether body systems are functioning normally.
Reveal sudden changes in a patient’s condition.
Reveal changes that occur progressively over time.
Any difference between a patient’s normal baseline measurement and present vital signs may indicate a need for therapies/medical interventions.
Pain, a subjective symptom, is often referred to as a vital sign.
Vital signs are included in routine physical assessment.

[Ask students: what are some examples of how vital sign measurements can be used? Discuss.]

Always obtain a baseline measurement of vital signs on first contact with a patient to serve as a basis for comparison with later vital sign measurements.
Frequency of vital sign measurements depend on the specific patient’s condition; you apply clinical judgement to decide which vital sign to measure, when to obtain measurements and the frequency of assessments.

[Review with students Box 5-1, When to Take Vital Signs.]

Be culturally sensitive when taking vital sign measurements
Protect patient privacy
Observe patient cultural norms
Be considerate of patient anxiety

Patient-Centered Care

Privacy
Vital sign measurements require removing clothing or exposing areas considered inappropriate or offensive to patients from other cultures.
Be sensitive to each patient’s need for privacy and observe cultural norms.
Provide privacy when performing apical pulse assessment, especially for traditional female patients and elders from Asian, Middle Eastern, Hispanic, and African cultures.
Anxiety
Even noninvasive procedures sometimes produce anxiety because of cultural variables of touch, privacy, and gender.
Cultural norms and health information
When findings are reported, patients from cultures with paternalistic values rely on a male elder to receive information on their behalf.
Consult the health care provider and the family decision maker about giving information to the patient regarding abnormal vital signs.
Collectivistic cultures (e.g., Hispanics, Africans, Asians) demonstrate their caring for ill members by protecting them from bad news about their health and well-being.

Measurement considerations
Deep breathing during BP measurement
Talking

Evidence-Based Practice

Obtaining an accurate and reliable blood pressure requires consideration of measurement conditions.
Deep breathing during blood pressure measurement decreases systolic and diastolic blood pressure nearly 5 mm Hg.
Talking, especially when communicating sensitive or stressful information, increases systolic and diastolic blood pressure up to 6 mm Hg
Two studies established that placing a blood pressure cuff over a sleeved arm in either hypertensive patients (Pinar, 2010) or normotensive patients (Ki et al., 2013) had no effect on blood pressure measurements

Safety Guidelines

Nurses analyze vital signs to interpret their significance and to make decisions about appropriate interventions.

2. [Ask students: how does function of the equipment affect safety?]

3. A patient’s usual values may differ from the acceptable range for that age or physical state. They serve as a baseline for comparison with later findings; thus you detect changes in condition over time.

Safety Guidelines (Cont.)

Some illnesses or treatments cause predictable vital sign changes. Most medications affect at least one of the vital signs.
Environmental factors: for example, assessing the patient’s temperature in a warm, humid room may yield a value that is not a true indicator of the patient’s condition.
[Ask students: why does a step-by-step approach ensure accuracy when vital signs are taken? Discuss.]

Safety Guidelines (Cont.)

After surgery or treatment intervention, measure vital signs more frequently to detect complications. In a clinic or outpatient setting, take vital signs before the health care provider examines the patient and after any invasive procedures are performed. As a patient’s physical condition worsens, it is important to monitor the vital signs as often as every 5 to 15 minutes. You are responsible for judging whether more frequent assessments are necessary.
Do not interpret vital signs in isolation. You need to know related physical signs or symptoms and must be aware of the patient’s ongoing health status.
Baseline measurements allow a nurse to identify changes in vital signs. When vital signs appear abnormal, it helps to have another nurse repeat the measurement. Inform the health care provider when vital signs become abnormal, and report any changes to the nurse in charge.

Measuring Body Temperature
Skill 5-1

Goal: to obtain a representative average temperature of core body tissues
Normal range: 36C to 38C (96.8F to 100.4F)

Body temperature
Difference between the amount of heat produced by body processes and the amount of heat lost to the external environment.
Core temperature is under control of the hypothalamus and remains in a narrow range.
Body surface temperature fluctuates dramatically in response to the environment.
No single temperature is normal for all people.
Body tissues and cells function best within a relatively narrow temperature range, from 36C to 38C (96.8F to 100.4F).

[Shown is Figure 5-1: Ranges of normal temperature values and physiological consequences of abnormal body temperature.]

For healthy young adults, the average oral temperature is 37C (98.6F).
An acceptable temperature range for adults depends on age, gender, range of physical activity, hydration status, and state of health.
Physiological and behavioral control mechanisms act to maintain a constant core temperature.
Control mechanisms have failed when heat produced by the body is not equal to heat lost to the environment. [Ask students: what are some examples of failed control mechanisms? Discuss: patients without sweat gland function.]
Fever occurs when heat loss mechanisms are unable to keep pace with excess heat production, resulting in an abnormal rise in body temperature.
When an individual has a febrile condition (i.e., pyrexia), initiate temperature-control measures such as controlling environmental temperatures, removing external coverings, and administering ordered antipyretics to achieve better temperature control.

Core temperature measurement sites
Tympanic membrane
Urinary bladder
Temporal artery
Rectum
Esophagus
Pulmonary artery

Measuring Body Temperature
Skill 5-1 (Cont.)

Average usual temperature varies, depending on the measurement site used.
Rectal temperatures are usually 0.5° C (0.9° F) higher than oral temperatures.
Axillary and tympanic temperatures are usually 0.5° C (0.9° F) lower than oral temperatures.
Sites reflecting core temperature (e.g., tympanic membrane) are more reliable indicators of body temperature than sites reflecting surface temperatures.
To ensure accurate temperature readings, you need to measure each site correctly.
Use the same site when repeated measurements are necessary or when temperature measurements are compared over time.

[Review with students Box 5-3, Advantages and Limitations of Select Temperature Measurement Sites.]

Several types of thermometers are commonly available to measure body temperature.
Mercury-in-glass thermometers are no longer used in health care settings but may be found in patients’ homes.

[Ask students: why are mercury-in-glass thermometers no longer used in health care settings? Discuss: potential mercury hazards.]

[Review with students Box 5-4, Types of Thermometers.]

The nurse is checking the patient’s core temperature. Which site is the nurse using?

Skin

Tympanic membrane

Axilla

Oral cavity

Quick Quiz!

Correct answer: B

Rationale: All other sites are considered surface measurement sites.

The task of temperature measurement can be delegated to nursing assistive personnel (NAP)
The nurse instructs NAP to:
Communicate the appropriate route, device, and frequency of temperature measurement
Explain any rectal positioning precautions
Review temperature values/significant changes to report to the nurse

Delegation and Collaboration

The nurse instructs nursing assistive personnel (NAP) to:
Communicate the appropriate route, device, and frequency of temperature measurement.
Explain any precautions needed in positioning the patient for rectal temperature measurement.
Review the usual temperature values and significant changes to report to the nurse.

Recording and Reporting

Record temperature and route on vital sign flow sheet or in electronic health record (EHR)

Record temperature site on vital sign flow sheet or in EMR or nurses’ notes

Report abnormal findings to nurse in charge or health care provider

Teaching
Maintaining body temperature
Risk factors for hypothermia, frostbite, and heatstroke
Taking antibiotics as directed
Pediatric
Physiological differences

Special Considerations

Teaching
Identify patient’s ability to initiate preventive health measures and recognize alterations in body temperature. Teach patients and family members about measures to prevent body temperature alterations.
Teach patients about risk factors for hypothermia and frostbite including fatigue; malnutrition; hypoxemia; cold, wet clothing; and alcohol intoxication.
Teach patients about risk factors for heatstroke: strenuous exercise in hot, humid weather; tight-fitting clothing in hot environments; exercising in poorly ventilated areas; sudden exposure to hot climates; and poor fluid intake before, during, and after exercise.
Teach patients about the importance of taking and continuing antibiotics as directed until the course of treatment for infection is completed
Pediatric
Infants and young children may lose more heat to the environment because of their increased body surface area/volume ratios.
Critically ill children sometimes have cool skin but a high core temperature because of poor perfusion to the skin.
Use axillary temperatures for screening purposes only; axillary temperature cannot be relied on to detect fever in infants and young children.
Children may assume a prone position for rectal temperature measurement.
With children who cry or become restless, it is best to take temperature as the last vital sign.

Gerontological
Lower normal temperature
Physiological differences
Home care
Environmental conditions that influence temperature
Mercury-in-glass thermometers

Special Considerations (Cont.)

Gerontological
The temperature of older adults is at the lower end of the acceptable temperature range: 36° C (96.8° F).
Temperatures considered within normal range often reflect a fever in an older adult.

[Ask students: what are some of the physiological differences in older adults that cause complications with getting an accurate temperature reading? Discuss:]

Adults without teeth or older adults with poor muscle control may be unable to close their mouth tightly enough to provide an accurate oral temperature reading.
Older-adult thermoregulatory systems are not as efficient as those of younger adults.
Tympanic temperature measurements can be inaccurate because of a buildup of cerumen.
Decreased sweat gland reactivity, loss of subcutaneous fat reducing the insulating capacity of the skin, diminished sensation to cold, abnormal vasoconstrictor responses, and impaired shivering can interfere with temperature regulation in the older adult.
With aging a loss of subcutaneous fat reduces the insulating capacity of the skin.
Older adults are at high risk for hypothermia because of diminished sensation to cold, abnormal vasoconstrictor responses, and impaired shivering
Home care
Assess temperature and ventilation of patient’s environment to determine the existence of any environmental conditions that may influence patient’s temperature.
Mercury-in-glass thermometers.
Assess safe storage of these thermometers.
Teach patient and family caregiver about proper use of the thermometer, mercury hazards, and proper disposal of any mercury-containing devices.
Suggest alternative temperature measurement devices for home use.

Assessing Radial Pulse
Skill 5-2

Goal: to assess the integrity of the cardiovascular system
Radial and carotid arteries commonly used

The ejection of blood from the heart distends the walls of the aorta. Because of the force of the blood exiting the heart, aortic distention creates a pulse wave that travels rapidly toward the extremities. When the pulse wave reaches a peripheral artery, you can feel it by palpating the artery lightly against underlying bone or muscle.
The pulse is the palpable bounding of the blood flow.
The number of pulsing sensations occurring in 1 minute is the pulse rate.
Assessing a patient’s peripheral pulses determines the integrity of the cardiovascular system.
An abnormally slow, rapid, or irregular pulse indicates an inability of the heart to deliver adequate blood to the body; a pulse deficit may be present.
The strength or amplitude of a pulse reflects the volume of blood ejected against the arterial wall with each heart contraction.
If volume decreases, the pulse often becomes weak and difficult to palpate.
A full bounding pulse is an indication of increased volume.
The integrity of peripheral pulses indicates the status of blood perfusion to the area distributed by the pulse.

[Ask students: what does it indicate if a pulse distal to an injured area of an extremity feels week on palpation? Discuss: the volume of blood reaching tissues below the affected area may be inadequate, and surgical intervention may be necessary.]

The radial and carotid arteries are commonly used because they are easy to palpate.
Other peripheral pulses are assessed when a complete physical is conducted, or when the radial artery is not available for assessment because of surgery, trauma, or impaired blood flow.

[Review with students Table 5-1, Pulse Sites.]

[Shown is Figure 5-6: Palpating right radial pulse.]

Radial pulse measurement task can be delegated to NAP if patient is stable
The nurse instructs NAP to:
Communicate appropriate pulse rate site; measurement frequency; and factors related to patient history
Review and report patient’s usual pulse rate and significant changes
Report specific abnormalities

Delegation and Collaboration

The task of radial pulse measurement cannot be delegated when the patient’s condition is unstable because the patient is at high risk for acute or cardiac problems, or when the nurse is evaluating patient response to treatment or medication.
The nurse instructs the NAP to:
Communicate the appropriate site for pulse rate; frequency of measurement; and factors related to the patient history such as risk for abnormally slow, rapid, or irregular pulse.
Review patient’s usual pulse rate and significant changes to report to the nurse.
Report specific abnormalities to the nurse for further nursing assessment.

Recording and Reporting

Record pulse rate and assessment site on vital sign flow sheet or in EHR or chart

Document in EHR or chart the measurement of pulse rate after administration of specific therapies

Report abnormal findings to nurse in charge or health care provider

Record apical pulse rate and rhythm on vital sign flow sheet or nurses’ notes in chart or EHR. If apical pulse not found at fifth ICS and left MCL, document location of PMI.

Teaching
Self-assessment of pulse rates

Response to medications/exercise

Pediatric
Apical, femoral, or brachial pulse is best for young children
Sinus dysrhythmia
Breath holding

Special Considerations

Teaching
Teach family caregivers of patients taking prescribed cardiotonic or antidysrhythmic medications how to assess apical pulse rates to detect side effects of medications.
Patients undergoing cardiac rehabilitation need to learn to assess their own pulse rates to determine their response to exercise.
Teach patients taking heart medications or starting a prescribed exercise regimen how to monitor carotid pulse rate.
Pediatric
Radial artery is difficult to assess in an infant. Apical, femoral, or brachial pulse is best site for assessing pediatric heart rate and rhythm until 2 years of age.
Children often have a sinus dysrhythmia, which is an irregular heartbeat that speeds up with inspiration and slows down with expiration.
Breath holding in a child temporarily lowers pulse rate.

Gerontological
Reduced heart rate with exercise
Slow cardiovascular response increase/decrease
Peripheral vascular disease makes radial pulse assessment difficult
Home care
Self-assessment of pulse rates

Special Considerations (Cont.)

Gerontological
Older adults have a reduced heart rate with exercise because of decreased responsiveness to catecholamines
It takes longer for the heart rate to rise in an older adult to meet sudden increased demands that result from stress, illness, or excitement. Once elevated, the pulse rate of an older adult takes longer to return to a normal resting rate.
Peripheral vascular disease is more common among older adults, making radial pulse assessment difficult.
Home care
Patients taking certain prescribed cardiac medications should learn to assess their own pulse rate to detect side effects of medications.

Assessing Apical Pulse
Skill 5-3

Goal: to assess cardiac function
Each apical pulse is the combination of two sounds: S1 and S2

The apical pulse is the most reliable noninvasive way to assess cardiac function.
The apical pulse rate is the assessment of the number and quality of apical sounds in 1 minute.
S1 is the sound of the tricuspid and mitral valves closing at the end of ventricular filling, just before systolic contraction begins; S2 is the sound of the pulmonic and aortic valves closing at the end of the systolic contraction.
A stethoscope is used to auscultate sound waves of the apical pulse.
The five major parts of the stethoscope are the earpieces, binaurals, tubing, bell, and diaphragm.
Diaphragm
Transmits high-pitched sounds created by high-velocity movement of air and blood.
Position to make a tight seal against the patient’s skin. Exert enough pressure to complete the seal, leaving a temporary red ring on the patient’s skin after you remove the diaphragm.
Bell
Transmits low-pitched sounds created by the low-velocity movement of blood.
Hold lightly against the skin for sound amplification.

[Shown is Figure 5-7: Acoustic stethoscope.]

The task of apical pulse measurement can be delegated to NAP if the patient is stable and is not at high risk for acute or serious cardiac problems
The nurse instructs NAP to:
Communicate measurement frequency and factors related to patient history
Review patient values and report to the nurse any abnormalities

Delegation and Collaboration

Often you measure the apical pulse when you suspect an irregularity in the radial pulse, or when a patient’s condition requires a more accurate assessment; in this situation, pulse assessment cannot be delegated to NAP.
When measurement of apical pulse is a routine practice, the nurse instructs the NAP to:
Communicate the frequency of measurement and factors related to the patient history, such as risk for abnormally slow, rapid, or irregular pulse.
Review the patient’s usual pulse values and the need to report to the nurse any abnormalities in rate or rhythm.

Recording and Reporting

Record rate and rhythm on vital sign flow sheet or in EMR or nurses’ notes

Document in appropriate area of EMR apical pulse rate measurement after administration of therapies

If apical pulse not found at fifth intercostal space (ICS) and left midclavicular line (LMCL), document location of point of maximal impulse (PMI)

Report abnormal findings

Record apical pulse rate and rhythm on the vital sign flow sheet or in the EMR or nurses’ notes.
Document in the appropriate area of the EMR measurement of apical pulse rate after administration of specific therapies, as per agency policy.
If apical pulse is not found at the fifth intercostal space (ICS) and the left midclavicular line (LMCL), document the location of the point of maximal impulse (PMI).
Report abnormal findings to the nurse in charge or the health care provider.

Teaching
Caregivers of patients prescribed cardiotonic/antidysrhythmic medications
Pediatric
PMI differences
Count apical pulse for 1 full minute until age 2 years
Breath holding affects pulse rate

Special Considerations

Teaching
Teach caregivers of patients taking prescribed cardiotonic or antidysrhythmic medications how to assess apical pulse rates.

[Ask students: why should caregivers of patients taking prescribed cardiotonic or antidysrhythmic medications learn to assess apical pulse rates? Discuss: to detect side effects of medications.]

Pediatric
The PMI of an infant is usually located at the third to fourth ICS near the left sternal border.
In infants and children younger than 2 years, an apical pulse is more reliable and is counted for 1 full minute because of possible irregularities in rhythm.
Breath holding in an infant or child affects apical pulse rate.

Gerontological
Physiological changes can make the PMI difficult to palpate
Lift sagging breast tissue if necessary
Decreased resting heart rate
Home care
Quiet location for auscultation

Special Considerations (Cont.)

Gerontological
The PMI is often difficult to palpate in some older adults because the anterior-posterior diameter of the chest increases with age and the heart becomes repositioned because of left ventricular enlargement.
When assessing older adult women with sagging breast tissue, gently lift the breast tissue and place the stethoscope at the fifth ICS or at the lower edge of the breast.
Heart sounds are sometimes muffled or difficult to hear in older adults because of increased air space in the lungs.
The older adult has a decreased heart rate at rest.
Home care
Assess the home environment to determine which room affords a quiet environment for auscultation of apical rate.

Assessing Respirations
Skill 5-4

Respiration: the exchange of oxygen (O2) and carbon dioxide (CO2)
Assess ventilation
by observing rate, depth, and rhythm
of respiratory movements

Respiration is the exchange of oxygen (O2) and carbon dioxide (CO2) between cells of the body and the atmosphere.
Three processes of respiration are ventilation, diffusion, and perfusion.
You assess ventilation by observing the rate, depth, and rhythm of respiratory movements.
On inspiration, the diaphragm contracts and the abdominal organs move down to increase the size of the chest cavity. At the same time, the ribs and the sternum lift outward to promote lung expansion.
On expiration, the diaphragm relaxes upward, and the ribs and the sternum return to their relaxed position.
During quiet breathing the chest wall gently rises and falls.
The body uses more energy during inspiration than during expiration.

[Shown is Figure 5-8: Diaphragmatic and chest wall movement during inspiration and expiration.]

The task of counting respirations can be delegated to NAP unless the patient is considered unstable
The nurse instructs the NAP to:
Communicate measurement frequency and factors related to patient history/risk for respiratory rate changes
Review and report unusual respiratory values and significant changes

Delegation and Collaboration

The task of counting respirations can be delegated to NAP unless the patient is considered unstable (e.g., complaints of dyspnea).
The nurse instructs the NAP to:
Communicate the frequency of measurement and factors related to patient history or risk for increased or decreased respiratory rate or irregular respirations.
Review any unusual respiratory values and significant changes to report to the nurse.

Recording and Reporting

Record respiratory rate on vital sign flow sheet or in EHR or chart

Document respiratory rate measurement after administration of specific therapies

Record type and amount of oxygen therapy, if used

Report abnormal findings to nurse in charge or health care provider

Record respiratory rate on vital sign flow sheet or in EMR or nurses’ notes.
Document in the EMR or nurses’ notes measurement of respiratory rate after administration of specific therapies.
Record in EMR or nurses’ notes the type and amount of oxygen therapy, if used.
Report abnormal findings to the nurse in charge or the health care provider.

Teaching
Deep-breathing and coughing exercises
Pediatric
Assess respiratory rates first, before other vital signs
Be aware of physiological differences

Special Considerations

Teaching
Patients who demonstrate decreased ventilation often benefit from learning deep-breathing and coughing exercises.
Instruct family caregiver to contact home care nurse or health care provider if unusual fluctuations in respiratory rate occur.
Pediatric
Assess respiratory rates before other vital signs or assessments if you are able to view movement of the chest wall or abdomen. This allows assessment of rate and rhythm before child becomes anxious because of stranger anxiety or fear of other assessment procedures.
Average respiratory rate (breaths per minute) for newborns is 30 to 60; for infants (6 months to 1 year) 30; for toddlers (2 years) 25 to 32; and for children from 3 to 12 years 20.
Children up to age 7 breathe abdominally; thus respirations are observed by abdominal movement.
An irregular respiratory rate and short apneic spells are normal for newborns.
Nurses can simply observe the infant or young child while the chest and abdomen are exposed.
Use cardiorespiratory monitors for infants or newborns who are at risk for respiratory compromise or sustained apnea.

Gerontological
Restricted chest expansion
Reduced depth of respirations
Change in lung function
Dependence on accessory muscles
Home care
Assess for environmental factors that influence patient respiratory rate

Special Considerations (Cont.)

Gerontological
Aging causes ossification of costal cartilage and downward slant of ribs, resulting in a more rigid rib cage, which reduces chest wall expansion. Kyphosis and scoliosis, frequent in older adults, may also restrict chest expansion.
Depth of respirations tends to decrease with aging.
Change in lung function with aging generally results in respiratory rates that are higher in older adults, with a range of 16 to 25 breaths/min.
Some older adults depend more on accessory abdominal muscles than weakened thoracic muscles during respiration.
Home care
Assess for environmental factors in the home that influence patient’s respiratory rate, such as secondhand smoke, poor ventilation, or gas fumes.

The nurse receiving the report is told that her patient is having Cheyne-Stokes respirations. What will the nurse expect to find when assessing this patient?

Slow but normal breathing rate

Increased depth of respirations

Alternating periods of apnea and hyperventilation

Cessation of respirations for several seconds

Quick Quiz!

Correct answer: C

Rationale: In Cheyne-Stokes respiration, the respiratory rate and depth are irregular, characterized by alternating periods of apnea and hyperventilation. The respiratory cycle begins with slow, shallow breaths that gradually increase to abnormal rate and depth.

Assessing Arterial Blood Pressure
Skill 5-5

Blood pressure (BP)
is commonly
assessed with a sphygmomanometer and a stethoscope
Korotkoff phases: five sounds heard over an artery

Blood pressure (BP) is the force exerted by blood against the vessel walls. Peak pressure occurs when the ventricular contraction of the heart, or systole, forces blood under high pressure into the aorta. When the ventricles relax, the blood remaining in the arteries exerts a minimal or diastolic pressure. Diastolic pressure is the minimal pressure exerted against the arterial wall at all times.
The standard unit for measuring blood pressure is millimeters of mercury (mm Hg).
As the sphygmomanometer cuff is deflated, the five different sounds heard over an artery are called Korotkoff phases.
The sound in each phase has unique characteristics.
Blood pressure is recorded with the systolic reading (first Korotkoff sound) before the diastolic reading (beginning of the fifth Korotkoff sound).

[Shown is Figure 5-9: The sounds auscultated during blood pressure measurement can be differentiated into five Korotkoff phases. In this example, the blood pressure is 140/90 mm Hg.]

The difference between systolic and diastolic pressure is the pulse pressure. (For a blood pressure of 120/80, the pulse pressure is 40.)

Assessing Arterial Blood Pressure Skill 5-5 (Cont.)

Hypertension
Prehypertension
Hypotension
Orthostatic
Blood pressure equipment

Hypertension
Defined as systolic blood pressure (SBP) of 140 mm Hg or greater, diastolic blood pressure (DBP) of 90 mm Hg or greater, or taking antihypertensive medication.
Prehypertension is a designation for patients at high risk for developing hypertension. [Ask students, what can you do to help a patient promote a healthy lifestyle and avoid a hypertension diagnosis?]
The diagnosis of hypertension in adults requires the average of two or more readings taken at each of two or more visits after an initial screening.

[Review with students Table 5-2, Classification of Blood Pressure for Adults Ages 18 Years and Older.]

[Review with students Table 5-3, Recommendations for Blood Pressure Follow-up.]

Hypotension
Occurs when the systolic blood pressure falls to 90 mm Hg or below. Although some adults normally have a low blood pressure, for most people a low blood pressure is an abnormal finding associated with illness.
Orthostatic hypotension, also referred to as postural hypotension, occurs when a normotensive person develops symptoms (e.g., light-headedness, dizziness) and low blood pressure when rising to an upright position.
Blood pressure equipment
You can measure arterial blood pressure directly (invasively) or indirectly (noninvasively).
The direct method requires electronic monitoring equipment and the insertion of a thin catheter into an artery.
The more common noninvasive method requires use of the sphygmomanometer and stethoscope.
Cloth or disposable vinyl compression cuffs contain an inflatable bladder and come in several different sizes.
An improperly fitting cuff produces inaccurate blood pressure measurements.

[Shown is Figure 5-10: Guidelines for proper blood pressure cuff size. Cuff width equals 20% more than upper arm diameter or 40% of circumference around upper arm and two thirds of upper arm length.]

[Review with students Box 5-6, Common Mistakes in Blood Pressure Assessment.]

Electronic or automatic blood pressure machines consist of an electronic sensor positioned inside a blood pressure cuff attached to an electronic processor.
Electronic devices have limitations but are useful when frequent measurements are necessary.

[Review with students Box 5-7, Advantages and Limitations of Assessing Blood Pressure Electronically.]

The task of blood pressure measurement can be delegated to NAP unless patient is unstable
The nurse instructs NAP to:
Explain the procedure
Communicate frequency and factors related to patient history
Review and report blood pressure values, changes, or abnormalities

Delegation and Collaboration

The task of blood pressure measurement can be delegated to NAP unless the patient is considered unstable (e.g., hypotensive)
The nurse instructs NAP to:
Explain the appropriate limb for measurement, blood pressure cuff size, and equipment (manual or electronic) to be used.
Communicate the frequency of measurement and factors related to the patient’s history such as risk for orthostatic hypotension.
Review the patient’s usual blood pressure values and significant changes or abnormalities to report to the nurse.

Recording and Reporting

Record blood pressure and site assessed on vital sign flow sheet or in EHR or chart

Document measurement of blood pressure after administration of specific therapies

Report abnormal findings to nurse in charge or health care provider

Record blood pressure and site assessed on vital sign flow sheet or in EHR or chart.
Where should BP be documented after administration of specific therapies? EMR or nurses’ notes.
Report abnormal findings to nurse in charge or health care provider.

[Ask students: why is it important to report abnormal findings to the nurse in charge?]

Teaching
Risks for hypertension
Time and position to take blood pressure
Pediatric
Not routine for children younger than 3 years old
Risk of anxiety
Korotkoff sounds difficult to hear

Special Considerations

Teaching
People with family history of hypertension, premature heart disease, lipidemia, or renal disease are at significant risk. Obesity, cigarette smoking, heavy alcohol consumption, high blood cholesterol and triglyceride levels, and continued exposure to stress from psychosocial and environmental conditions are factors linked to hypertension.
Primary prevention of hypertension includes lifestyle modifications (e.g., lose weight, exercise daily, reduce sodium and saturated fat intake, maintain adequate intake of dietary potassium and calcium). Cigarette smoking is a significant risk factor; thus encourage patients to avoid tobacco in any form.
Instruct primary caregiver to take blood pressure at the same time each day and after patient has had a brief rest. Take blood pressure sitting or lying down; use the same position and arm each time you take pressure.
Instruct primary caregiver that if the blood pressure is difficult to hear, this is probably caused by one of the following: cuff too loose, not large enough, or too narrow; stethoscope not over arterial pulse; cuff deflated too quickly or too slowly; or cuff not pumped high enough for systolic readings.
Pediatric
Blood pressure measurement is not a routine part of assessment in children younger than 3 years.
Blood pressure measurement can frighten children. Prepare child for the squeezing feeling of an inflated blood pressure cuff by comparing sensation with an elastic band on the finger or a tight hug on the arm.
Obtain blood pressure reading in a child before performing anxiety-producing tests or procedures.
Blood pressure sounds are difficult to hear in children because of low frequency and amplitude. Using the bell of a pediatric stethoscope is often helpful.

Gerontological
Susceptible to cuff pressure injury
Increased systolic pressure
Fall in blood pressure after eating
Postural hypotension
Home care
Equipment/environment recommendations

Special Considerations (Cont.)

Gerontological
Older adults, especially frail older adults, have lost upper arm mass, requiring special attention to selection of blood pressure cuff size.
Skin of older adults is more fragile and susceptible to cuff pressure when measurements are frequent. More frequent assessment of skin under the cuff or rotation of measurement sites is recommended.
Older adults have an increase in systolic pressure related to decreased vessel elasticity.
Older adults often experience a fall in blood pressure after eating.
Instruct older adults to change position slowly and to wait after each change to avoid postural hypotension and prevent injury.
Home care
Assess home noise level to identify the room that provides the quietest environment for assessing blood pressure.
Instruct patient on the importance of a blood pressure cuff of appropriate size for home use.
Assess family’s financial ability to afford a sphygmomanometer for performing blood pressure evaluations on a regular basis.
Recommend electronic devices or aneroid sphygmomanometers that have proved accurate according to standard testing and cuffs of appropriate size.
Finger blood pressure monitors are inaccurate.

Noninvasive Electronic Blood Pressure Measurement
Procedural Guideline 5-1

Used when frequent assessment is required
Critically ill/potentially unstable patients; during/after invasive procedures; therapies requiring frequent monitoring

[Shown is Figure 5-12: Noninvasive electronic blood pressure machine.]

Electronic machines rely on an electronic sensor to detect vibrations caused by the rush of blood through an artery.
These devices are used when frequent assessment is required, as in critically ill or potentially unstable patients, during or after invasive procedures, or when therapies require frequent monitoring.
Verify assessment of an abnormal blood pressure by an electronic machine with a sphygmomanometer and a stethoscope.

The task of blood pressure measurement using an electronic blood pressure machine can be delegated to NAP unless the patient is considered unstable
The nurse instructs NAP to:
Communicate measurement information
Select appropriate blood pressure cuff
Review and report patient information

Delegation and Collaboration

[Ask students, what is an example of the patient being considered unstable?]

The nurse instructs NAP to:

Communicate the frequency and extremity for measurement.
Select a blood pressure cuff of appropriate size for the designated extremity and an appropriate cuff for the machine.
Review patient’s usual blood pressure and report significant changes or abnormalities to the nurse.

The nurse is preparing to assess the blood pressure of an adult patient, using a thigh cuff on an electronic BP monitor. The nurse should use a cuff of what size for this patient?

17 to 25 cm

23 to 33 cm

31 to 40 cm

38 to 50 cm

Quick Quiz!

Correct answer: D

Rationale: This is the correct size of cuff for a thigh measurement. All other answers are incorrect because they are not measurements for a thigh cuff.

Noninvasive measurement of arterial blood oxygen saturation
A probe with a light-emitting diode (LED) measures oxygenated hemoglobin molecules
Probes can be applied to the earlobe, finger, toe, bridge of nose, or forehead
Normal pulse oximetry (SpO2) is greater than 95%

Measuring Oxygen Saturation (Pulse Oximetry)
Procedural Guideline 5-2

A pulse oximeter is a probe with a light-emitting diode (LED) connected by a cable to an oximeter.
The LED emits light wavelengths that are absorbed differently by oxygenated and deoxygenated hemoglobin molecules.
The more hemoglobin is saturated by oxygen, the higher is the oxygen saturation.
Measurement of oxygen saturation is simple and painless.
A vascular, pulsatile area is needed to detect the change in transmitted light when measurements are taken with a digit or earlobe probe.
Complications
Conditions that decrease arterial blood flow such as peripheral vascular disease, hypothermia, pharmacological vasoconstrictors, hypotension, or peripheral edema affect accurate determination of oxygen saturation.
Carbon monoxide in the blood, jaundice, and intravascular dyes can influence the light reflected from hemoglobin molecules.
The patient must remain still and outside light sources should be limited for optimal measurements.
Probe placement
A forehead sensor can be used for patients with decreased peripheral perfusion.
In adults, you can apply reusable and disposable oximeter probes to the earlobe, finger, toe, bridge of the nose, or forehead.
Pulse oximetry is indicated in patients who have an unstable oxygen status or are at risk for impaired gas exchange.

The task of oxygen saturation measurement can be delegated to NAP
The nurse instructs NAP to:
Explain to the patient factors that falsely lower O2 saturation
Use specific sensor site, probe, and frequency of oxygen saturation measurements for the patient
Notify the nurse of low O2 saturation readings
Not use pulse oximetry to assess heart rate

Delegation and Collaboration

The task of oxygen saturation measurement can be delegated to NAP.
The nurse instructs NAP to:
Communicate specific factors related to the patient that can falsely lower oxygen saturation.
Provide information about appropriate sensor site and probe.
Notify the nurse of frequency of oxygen saturation measurements for a specific patient.
Notify the nurse immediately of any reading lower than pulse oximetry (SpO2) of 95% or value for a specific patient.
Refrain from using pulse oximetry as an assessment of heart rate because an oximeter will not detect an irregular pulse.