Download Chapter 20: Measuring Vital Signs

JUDITH M. WILKINSON LESLIE S. TREAS
KAREN BARNETT MABLE H. SMITH
FUNDAMENTALS OF
NURSING
Chapter 20:
Measuring Vital Signs
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Vital Signs
• A means of assessing vital or critical
physiological functions
• Variations reflect a person’s state of health and/or
functional ability of the body systems
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Vital Signs (cont’d)
• One of the most frequent assessments you will make
as a nurse
• The importance of accurate assessments,
interpretation, and documentation of VS cannot be
overemphasized.
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Monitoring Vital Signs
• Performed on a regular basis
• Frequency determined by
– Provider’s prescription and/or nursing judgment
– Client’s condition
– Facility standards
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Facility Standards for Monitoring
• Hospital: every 4 to 8 hr
• Home health setting: each visit
• Clinic: each visit
• Skilled nursing facilities (SNFs): weekly to monthly
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Temperature
• Degree of heat maintained by the body
• Heat produced minus heat lost
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Core Temperature
• The “old standby”
normal range: 97°F to
100.8°F
(36.1°C to 38.2°C) with
some variation
• Typically 1°F to 2°F
(0.6°C to 1.2°C) higher
than skin temperature
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Surface Temperature
• Lower than core temperature
• Use oral and axillary method
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Changes in Temperature Can Occur Via…
• Conduction: Transfer
of heat from a warm to
a cool surface by
direct contact
• Convection: Transfer of
heat through currents of
air or water
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Changes in Temperature Can Occur Via…
(cont’d)
• Radiation: Loss of heat
through electromagnetic
waves emitting from surfaces
that are warmer than the
surrounding air
• Evaporation: Water is
converted to vapor and lost
from the skin (as
perspiration) or the mucous
membranes (through the
breath)
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Variances in Temperature
Fever (pyrexia)
• Abnormally high body temperature (>100°F or
37.8°C)
• Occurs in response to pyrogens (e.g., bacteria)
• Pyrogens induce secretion of substances
(prostaglandins) that reset the hypothalamic thermostat
at a higher temperature
Hyperpyrexia
• Fever >105.8°F (41.0°C)
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Variances in Temperature (cont’d)
Hypothermia
• Core temperature below normal (<95°F or 35°C)
• Associated with extended exposure to cold (e.g., extreme
weather, immersion in cold water, or lack of shelter and
clothing)
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Course of Fever
• Initial—Febrile episode
• Second—Course
• Third—Defervescence or crisis
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Pulse
The “wave” that begins when the left ventricle
contracts and ends when the ventricle relaxes
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Pulse (cont’d)
• Each contraction forces blood into the already-filled
aorta, causing increased pressure within the arterial
system.
• Systole is the peak of the wave, or contraction of the
heart.
• Diastole is the trough or resting phase of the heart.
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Pulse (cont’d)
Pulse rate
• Measured in beats per minute (bpm)
– Normal range for healthy adults = 60 to 100 bpm
– Average = 70 to 80 bpm
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Obtaining a Pulse Rate
• Apical is most accurate
• Use a stethoscope to auscultate the number of
heartbeats at the apex of the heart
• A heartbeat is one series of the LUB and DUB sounds
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Common Pulse Points
• Apical: At the apex of
the heart
• Carotid: Between midline
and side of neck. Only for
CPR-trained
professional; and
assessing circulation to
the head
• Brachial: Medially in
the antecubital space
• Radial: Laterally on the
anterior wrist
• Femoral: In the
groin fold
• Popliteal: Behind
the knee
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Variances in Pulse Rates
• Bradycardia: Rate <60 bpm
• Tachycardia: Rate >100 bpm
• Is the rate regular or irregular?
• What is the quality of the pulse?
– Bounding?
– Thready?
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Cardiac Efficiency
• Stroke volume: The quantity of blood pumped out
by each contraction of the left ventricle
• Cardiac output: Stroke volume × pulse (heart) rate
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Inadequate Circulation
If circulation is compromised, pallor or cyanosis may be
present
• Pallor: Paleness of skin when compared with another
part of the body
• Cyanosis: A bluish or grayish discoloration of the
skin due to excessive carbon dioxide and deficient
oxygen in the blood
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Respiration
• The exchange of oxygen and carbon dioxide in the body
• Two separate processes
– Mechanical
– Chemical
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Respiration (cont’d)
Mechanical
• Pulmonary ventilation; breathing
• Active movement of air in and out of the
respiratory system
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Respiration (cont’d)
Chemical
• Exchange of oxygen and carbon dioxide
• Transport of oxygen and carbon dioxide throughout the
body
• Exchange of gases between capillaries and tissues
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Mechanics of Respiration/
Pulmonary Ventilation
Inspiration
• Drawing air into the lungs
• Involves the ribs and diaphragm, creating negative pressure
and allowing air to flow into the lungs
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Mechanics of Respiration/
Pulmonary Ventilation (cont’d)
Expiration
• Relaxation of thoracic muscles and diaphragm, causing air
to expel from the lungs
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Changes in the Thoracic Cavity
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Variations in Assessment Findings
• Rate
– Apnea: Cessation of breathing
– Bradypnea: Abnormally slow
– Tachypnea: Abnormally fast
• Depth
– Deep
– Shallow
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Variations in Assessment Findings (cont’d)
• Rhythm
– Assessment of the pattern of respirations
– Abnormal: Cheyne-Stokes, Biot
• Effort
– Work of breathing
– Dyspnea: Labored breathing
– Orthopnea: Inability to breathe when horizontal
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Variations in Breath Sounds
• Wheeze: High-pitched continuous musical sounds,
usually heard on expiration
• Rhonchi: Low-pitched continuous sounds caused by
secretions in the large airways
• Crackles: Discontinuous sounds usually heard on
inspiration; may be high-pitched popping sounds or
low-pitched bubbling sounds
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Variations in Breath Sounds (cont’d)
• Stridor: A piercing, high-pitched sound heard
primarily during inspiration
• Stertor: Labored breathing that produces a snoring
sound
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Ventilation and Oxygenation
Hyperventilation
• Rapid and deep breathing resulting in excess loss of CO2
(hypocapnea)
• Client may complain of feeling light-headed and tingly.
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Ventilation and Oxygenation (cont’d)
Hypoventilation
• The rate and depth of respirations are decreased and
CO2 is retained.
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Tools to Measure Oxygenation
Arterial blood gases (ABGs)
• Directly measures the partial pressures of oxygen, carbon
dioxide, and blood pH
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Tools to Measure Oxygenation (cont’d)
Pulse oximetry
• Noninvasive method of monitoring respiratory status
• Uses an external device that measures oxygen saturation
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Counting the Respiratory Rate
• The nurse should count the respiratory rate (RR)
after taking the radial pulse.
• The patient can alter the rate and pattern
of respirations.
• RR must be accurate, especially in older adults.
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Blood Pressure (BP)
Pressure of the blood as it is forced against arterial
walls during cardiac contraction
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Blood Pressure (BP) (cont’d)
Systolic pressure
• Peak pressure exerted against arterial walls as
the ventricles contract and eject blood
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Blood Pressure (BP) (cont’d)
Diastolic pressure
• Minimum pressure exerted against arterial walls between
cardiac contractions when the heart is at rest
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Blood Pressure (BP) (cont’d)
• Measured in millimeters of mercury (mm Hg)
• Recorded as systolic pressure over diastolic pressure
(e.g., 120/80 mm Hg)
• Pulse pressure: The difference between the systolic
and diastolic pressures
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BP Regulation
Influenced by three factors
• Cardiac function
• Peripheral vascular resistance
• Blood volume
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BP Regulation (cont’d)
The body constantly regulates and adjusts arterial
pressure in order to supply blood to body tissues via
perfusion of the capillary beds.
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Measuring BP
Indirect or noninvasive
• Most common
• Accurate estimate of arterial BP obtained by external
measuring devices
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Measuring BP (cont’d)
Direct method
• This is done only in in-client setting.
• A catheter is threaded into an artery under sterile
conditions.
• It is attached to tubing that is connected to an electronic
monitoring system.
• Pressure is constantly displayed as a waveform on the
monitor screen.
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Measuring BP (cont’d)
Indirect method
Equipment
• Sphygmomanometer
– Consists of a vinyl or cloth cuff, a pressure bulb with a
regulating valve, and a manometer
• Stethoscope
– Used to auscultate the systolic and diastolic pressures
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Measuring BP (cont’d)
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Measuring BP (cont’d)
(Check the procedure in Volume 2 for the complete set of
steps for measuring BP.)
• Place stethoscope over an artery.
• Inflate the cuff; the artery is occluded as the pressure of the
cuff exceeds the pressure in the artery.
• Deflate the cuff; blood begins to flow rapidly through the
partially open artery, producing turbulent flow you will hear
through the stethoscope.
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Korotkoff’s Sounds
First sound
• As you deflate the BP cuff, a sound that occurs during
systole (systolic BP)
Second sound
• As you further deflate the cuff, a soft swishing sound
caused by blood turbulence
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Korotkoff’s Sounds (cont’d)
Third sound
• Begins midway through the BP and is a sharp, rhythmic
tapping sound
Fourth sound
• Similar to the third sound, but softer and fading
Fifth sound
• Silence, corresponding with diastole (diastolic BP)
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Hypotension
• Systolic blood pressure <100 mm Hg; some clients
normally have low BP; ask if client is light-headed or
dizzy.
• Orthostatic or postural hypotension is a sudden drop
in BP on moving from a lying to a sitting or standing
position.
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Hypertension
Prehypertension
• BP reading of 120 to 130 mm Hg systolic or 80 to 89
diastolic mm Hg
• Obtained with two readings, taken 6 min apart, with the
client sitting (JNC 7, 2003)
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Hypertension (cont’d)
Hypertension
• Diagnosed when BP is persistently higher than normal.
• Diagnosed when BP is >140 mm Hg systolic or
>90 mm Hg diastolic on two or more separate occasions.
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Hypertension (cont’d)
• This is a major cause of illness and death in the
United States.
• It increases the stress on the heart and blood vessels.
• If untreated, it can lead to heart, renal, cerebral, or
respiratory complications.
• Severity is directly related to the degree of elevation.
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Hypertension (cont’d)
Primary or essential hypertension
• Diagnosed when there is no known cause for the increase
• Accounts for at least 90% of all cases of hypertension
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Vital Signs: Combination of Skills
• Vital signs
–
–
–
–
Temperature
Pulse
Respirations
BP
• Provide an indication of a person’s state of health and
functioning of the body systems.
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Responsibility and Delegation
Nurses can delegate the activity of taking vital signs,
but the nurse is responsible for interpretation of vital
signs, vital sign trends, and decisions based on
abnormal vital sign findings.
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Responsibility and Delegation (cont’d)
As a student nurse, you are responsible for
functioning within your scope of knowledge.
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Think Like a Nurse
Recall the clients you encountered at the community health fair
(Meet Your Patients, in Volume 1). Two-year-old Jason’s axillary
temperature was 101.8°F (38.8°C); his skin was warm, dry, and
flushed. His mother told you that he had been eating poorly and
was very irritable.
• What changes in behavior alert you that something is wrong?
• Do you have enough theoretical knowledge or patient data to
know what is going on?
• What, if any, additional information about the patient
situation do you need to understand the meaning of Jason’s
temperature reading?
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