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CHAPTER 4
VITAL SIGNS
PRETEST
True or False
1. The heat-regulating center of the body is the medulla.
2. A vague sense of body discomfort, weakness and
fatigue that often marks the onset of a disease is
known as the blahs.
3. If an axillary temperature of 100° F was taken orally, it
would register as 101° F.
4. If the lens of a tympanic membrane thermometer is
dirty, the reading may be falsely low.
5. Chemical thermometers should be stored in the
freezer.
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2
PRETEST, CONT.
True or False
6. The femoral pulse site can be used to assess
circulation to the foot.
7. The term used to describe an irregularity in the
heart's rhythm is dysrhythmia.
8. Pulse oximetry provides the physician with
information on the amount of oxygen being delivered
to the tissues.
9. Blood pressure measures the contraction and
relaxation of the heart.
10. When taking blood pressure, the stethoscope is
placed over the brachial artery.
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Content Outline
Introduction to Vital Signs
1. Vital signs (VS): Objective guideposts that
provide data to determine a person's state of
health
2. Vital signs
a. Temperature
b. Pulse
c. Respiration
d. Blood pressure
e. Pulse oximetry: May be ordered routinely or when
patient complains of respiratory problems
(depending on office policy)
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Introduction to Vital Signs, cont.
3. Normal ranges are finely adjusted
a. Any deviation from normal may indicate
disease
4. Variations in VS may take place during
the course of an illness
5. MA should be alert to significant change
in VS and report it to physician
a. May indicate a change in patient's condition
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Introduction to Vital Signs, cont.
6. VS usually checked during each office
visit to establish:
a. Patient's state of health
b. Baseline measurements
•
Against which future measurements can be
compared
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Introduction to Vital Signs, cont.
7. Guidelines for Measuring Vital Signs:
a. Be familiar with normal ranges for VS
•
Vary based on different age groups
b. Make sure equipment is in proper working
condition
•
Ensures accurate readings
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Introduction to Vital Signs, cont.
c. Eliminate or minimize factors that affect
vital signs
•
Examples: exercise, food and beverage
consumption, emotional states
d. Use an organized approach when
measuring VS
•
If all the VS are ordered:
– Usually start with temperature, followed by
pulse, respiration, blood pressure, and
pulse oximetry
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8
Body Temperature
Regulation of Body Temperature
1. Maintained by hypothalamus
a. Functions as body's thermostat
b. Only allows temperature to vary 1° to 2° F
throughout day
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Regulation of Body Temperature
2. Temperature maintained through a
balance of:
a. Heat produced in the body
b. Heat lost from the body
3. Constant temperature range must be
maintained for body to function properly
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Regulation of Body Temperature,
cont.
4. When minor changes in temperature
occur
a. Hypothalamus senses this
•
Makes adjustments: so temperature stays
within normal range
•
Example: Playing tennis on a hot day
– Body's heat-cooling mechanism is activated
– Perspiration occurs to remove excess heat
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Heat Production
1. Heat produced through:
a. Voluntary and involuntary muscle
contractions
•
Voluntary: person can control (e.g., movement)
•
Involuntary: person cannot control (e.g.,
digestion, beating of heart, shivering)
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Heat Production
b. Cell metabolism
•
Heat produced when nutrients broken down in
the cells
c. Fever
d. Strong emotional states
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Heat Loss
1. Heat lost through:
a. Urine and feces
b. Water vapor from lungs
c. Perspiration: Moisture excreted through the
pores of the skin
•
When moisture evaporates: heat is released
– Cools body
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Heat Loss, cont.
d. Radiation: transfer of heat in the form of
waves
•
Body heat radiates to cooler surroundings
e. Conduction: transfer of heat from one
object to another by direct contact
•
Heat transferred to a cooler object it touches
f. Convection: transfer of heat through air
currents
•
Cool air currents cause body to lose heat
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Heat Loss, cont.
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Body Temperature Range
1. Purpose of measuring body
temperature:
a. Establish patient's baseline temperature
b. Monitor an abnormally high or low
temperature
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Body Temperature Range, cont.
2. Normal temperature range
a. 97º to 99º F (36.1º C to 37.2º C)
3. Average body temperature
a. 98.6º F (37º C)
4. Usually recorded using Fahrenheit
system
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Alterations in Body Temperatures
1. Fever (pyrexia): above 100.4º F
a. Heat being produced is greater than heat
being lost
2. Low-grade fever: 99º F to 100.4º F
3. Hyperpyrexia: above 105.8º F
a. Serious condition
b. Generally fatal: Above 109.4º F:
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•Alterations in Body Temperatures,
cont.
•
Hypothermia: below 97º F
•
Classified as subnormal
•
Heat being lost is greater than heat being
produced
•
Person usually cannot survive with a
temperature below 93.2º F
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Body Temperature
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Variations in Body Temperature
1. Normal fluctuations occur throughout
day
2. Factors that affect body temperature
a. Age
•
Infants and young children: higher temperature
than adults
– Heat-regulating system not yet fully
established
•
Elderly: lower temperature
– Loss of subcutaneous fat
– Loss of thermoregulatory control
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Variations in Body Temperature,
cont.
b. Diurnal variations: during sleep body
metabolism and muscle contractions slow
down
•
Causes temperature to be lowest in morning
c. Exercise: causes increase in voluntary
muscle contractions
•
Raises temperature
d. Emotional states: strong emotions increase
temperature (crying, extreme anger)
•
Infants/young children often cry during
examinations
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Variations in Body Temperature,
cont.
e. Environment
•
Cold weather: decreases temperature
•
Hot weather: increases temperature
f. Patient's normal body temperature: some
patients normally run low or high
temperatures
g. Pregnancy: cell metabolism increases
•
Raises temperature
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Fever
1. Common symptom of illness (particularly
inflammation and infection)
2. Febrile: person who has a fever
(above 100.4º F)
3. Afebrile: person who does not have a fever
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Fever, cont.
4. Pyrogen: any substance that produces fever
(e.g., pathogens)
a. Resets hypothalamus: causes temperature
to rise
5. Self-limiting fever: temperature returns to
normal after disease process completed
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Stages of a Fever
1. Onset: when temperature begins to rise
a. May be slow or sudden
b. Patient often experiences:
•
Coldness
•
Chills
•
Increase in pulse and respiratory rate
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Stages of a Fever, cont.
2. Course of a fever: temperature rises and
falls in one of three patterns:
a. Continuous: Body temperature fluctuates
minimally—always remains elevated
b. Intermittent: Body temperature alternately
rises and falls—at times returns to normal
or even becomes subnormal
c. Remittent: Wide range of temperature
fluctuations occurs
•
All are above normal
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Fever Patterns
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Stages of a Fever, cont.
•
During the course of a fever:
– Increased pulse and respiratory rate
– Feels warm to touch
– May also experience:
1) Flushed appearance
2) Increased thirst
3) Loss of appetite
4) Headache
5) Malaise
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Stages of a Fever, cont.
•
Malaise: A vague send of body discomfort,
weakness, and fatigue
– Often marks the onset of a disease
– Continues through the course of the illness
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Stages of a Fever, cont.
3. Subsiding stage: temperature returns to
normal
a. Can return gradually or suddenly (crisis)
b. Patient perspires and may become
dehydrated
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Assessment of Body Temperature
1. Assessment Sites
a. Mouth
b. Axilla
c. Rectum
d. Ear
e. Forehead
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Assessment of Body Temperature,
cont.
1. Site should have an abundant blood
supply
a. So that temperature of entire body is
obtained
2. Site must be as closed as possible
(mouth, axilla, rectum, ear)
a. Prevents air from interfering with the
reading
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Assessment of Body Temperature,
cont.
4. Site chosen depends on:
a. Patient's age, condition, and state of
consciousness
b. Type of thermometer(s) available
c. Medical office policy
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Oral Temperature
5. Oral Temperature
a. Convenient and one of most common routes
b. When MA records temperature
•
Physician assumes taken through oral route
unless otherwise noted
c. Rich blood supply under the tongue on
either side of the frenulum linguae
•
Site for placement of thermometer
d. Patient must keep mouth closed to provide
a closed space
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Oral Temperature, cont.
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Axillary Temperature
6. Axillary Temperature
a. Recommended for toddlers and
preschoolers
•
Have trouble holding thermometer under the
tongue
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Axillary Temperature, cont.
b. Also recommended for:
•
Mouth-breathing patients
•
Patients with oral inflammation or oral surgery
c. Measures 1° F lower than oral route
d. Make a notation to indicate axillary route
was used
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Axillary Temperature
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Rectal Temperature
7. Rectal Temperature
a. Rectum is highly vascular
b. Provides the most closed cavity
c. Measures 1° F higher than oral route
d. Make a notation in patient's chart to
indicate rectal route used
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Rectal Temperature, cont.
e. Recommended for:
•
Infants and young children
•
Unconscious patients
•
Mouth-breathing patients
•
When greater accuracy is desired
f. Should not be used in newborn: danger of
rectal trauma
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Rectal Temperature, cont.
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Aural Temperature
8. Aural Temperature
a. Used with tympanic membrane
thermometer
b. Closed cavity that is easily accessible
c. More comfortable for patient
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Aural Temperature, cont.
d. Easier to measure temperature in:
•
Children younger than 6 years
•
Uncooperative patients
•
Patients unable to have their temperature taken
orally
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Aural Temperature, cont.
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Forehead Temperature
9. Forehead Temperature
a. Temporal artery: Major artery of head
•
Runs laterally across forehead and down the
side of neck
•
In forehead area: Located 2 mm below skin
surface
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Forehead Temperature, cont.
b. Ideal site to measure temperature:
•
Temporal artery is close to skin surface
•
Easily accessible
•
Constant steady flow of blood
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Forehead Temperature, cont.
c. Used to measure body temperature in
individuals of all ages:
•
Newborns
•
Infants
•
Children
•
Adults
•
Elderly
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Forehead Temperature, cont.
d. Results about the same as a rectal
temperature measurement
•
Approximately 1º F higher than oral temperature
•
Approximately 2º F higher than axillary
temperature
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Types of Thermometers
1. Four types
a. Electronic
b. Tympanic
c. Temporal artery
d. Chemical
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Mercury Glass Thermometer
2. Mercury glass thermometers no longer
used
a. Break easily and release mercury
b. Mercury can damage the nervous system
c. If released into the environment: harmful to
wildlife
d. Many cities have banned sale or use of
mercury
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Electronic Thermometer
3. Electronic Thermometer
a. Frequently used in medical office
b. Measures oral, axillary, and rectal
temperature
c. Measures temperature in 4 to 20 seconds
d. Results digitally displayed on a screen
e. Consists of interchangeable probes
attached to a battery-operated portable unit
•
Blue probe: oral and axillary temperature
•
Red probe: rectal temperature
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Electronic Thermometer, cont.
f. Disposable plastic
cover placed over the
probe
•
Prevents transmission
of microorganisms
between patients
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Electronic Thermometer, cont.
g. Probe is inserted into site and is left in
place until audible tone is heard
h. Temperature is displayed on screen
i. Probe cover should be ejected into regular
waste container
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Electronic Thermometer, cont.
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Tympanic Membrane Thermometer
4. Tympanic Membrane Thermometer
a. Used at aural site
b. Detects thermal energy radiated from
tympanic membrane
c. Battery-operated handheld device with a
sensor probe
•
Disposable plastic cover placed over the probe
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Tympanic Membrane Thermometer,
cont.
d. Placed in outer third of external ear canal
e. Activation button depressed momentarily
f. Results displayed in 1 to 2 seconds on a
digital screen
g. Probe cover is ejected into regular waste
container
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Tympanic Membrane Thermometer,
cont.
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Tympanic Membrane Thermometer,
cont.
h. Guidelines for Using a Tympanic Membrane
Thermometer
•
Determine if the tympanic thermometer can be
used to measure the patient's temperature
– Should not be used:
1) Patient with inflammation of external ear
canal (e.g., otitis externa)
2) When the ear contains a discharge such
as blood or pus
3) Excessive cerumen buildup that
occludes canal
a) Causes falsely low temperature
reading
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Tympanic Membrane Thermometer,
cont.
– Can be used:
1) Patient with otitis media
2) Normal amount of cerumen
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Tympanic Membrane Thermometer,
cont.
•
Determine if external factors are present that
may influence temperature reading
– If present: remove individual from the
situation and wait 20 minutes before taking
temperature
– External factors include:
1) Has been lying on one ear or the other
2) Had ears covered (e.g., hat, ear muffs)
3) Has been exposed to very hot or very
cold temperatures
4) Has been recently swimming or bathing
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Tympanic Membrane Thermometer,
cont.
•
Select temperature measurement system
desired
– Can be displayed in Fahrenheit or Celsius
– Follow the manufacturer's instructions
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Tympanic Membrane Thermometer,
cont.
•
Place the probe properly in the patient's
ear
– Most important factor in obtaining an
accurate temperature
1) Straighten the ear canal
a) Ear canal has an S shape:
obstructs view of tympanic
membrane
b) Straightening allows probe to
obtain a clear picture of
tympanic membrane
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Tympanic Membrane Thermometer,
cont.
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Tympanic Membrane Thermometer,
cont.
1) Seal opening of the ear
a) Insert probe tightly enough to
seal opening of ear without
causing patient discomfort
b) If canal not sealed: cooler
external air causes
thermometer to register a lower
temperature
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Tympanic Membrane Thermometer,
cont.
3) Position tip of probe toward opposite
temple
a) Allows sensor to obtain best
possible picture of tympanic
membrane
b) If positioned incorrectly: may
be aimed at ear canal
4) Results in falsely low reading
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Tympanic Membrane Thermometer,
cont.
•
Verify accuracy of temperature reading (if
needed)
– Use other ear
1) Are slight but insignificant differences
between right and left ear
– Before using same ear: wait 2 minutes to
allow temperature to stabilize.
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Tympanic Membrane Thermometer,
cont.
•
Check probe lens before taking temperature
–
Probe is covered with a lens that is transparent
to heat waves
–
To ensure accuracy: keep lens clean and intact
–
Before taking a temperature: check to make sure
lens is shiny and clear
–
Fingerprints, cerumen, and dust: reduce
transparency of lens
1) Results in falsely low temperature reading
–
If lens is damaged: thermometer cannot be used
(must be repaired)
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Tympanic Membrane Thermometer,
cont.
•
Respond appropriately to digital messages
– Message displayed during following
circumstances:
1) An attempt is made to take temperature
without changing cover
2) An attempt is made to take temperature
with no probe cover in place.
3) Battery is low.
4) Thermometer in need of repair
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Tympanic Membrane Thermometer,
cont.
•
Care for thermometer properly
– Probe lens
1) Dust and other debris can build up on
lens
2) Clean as part of routine maintenance or
when it becomes dirty
a) Gently wipe surface with
alcohol wipe
b) Immediately wipe dry with
cotton swab
c) After cleaning: allow at least 5
minutes before taking
temperature
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Tympanic Membrane Thermometer,
cont.
– Thermometer casing
1) Clean casing periodically
a) Wipe dry with soft cloth
dampened with warm water
and mild detergent or
germicidal cleaner.
b) Make sure cloth is damp but not
wet: prevents cleaning solution
from running inside
thermometer (could damage it)
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Tympanic Membrane Thermometer,
cont.
•
Store thermometer properly
– Keep away from temperature extremes: could
damage thermometer
– Should not be exposed to:
1) Excessive heat (more than 95° F, or 35° C)
2) Excessive cold (less than 60° F, or 15.6° C)
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What Would You Do?
What Would You Not Do?
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What Would You Do?
What Would You Not Do?
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Temporal Artery Thermometer
5. Temporal Artery
Thermometer
a. Newest method for
measuring body
temperature
b. Electronic device:
Probe attached to a
portable unit
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Temporal Artery Thermometer,
cont.
c. To perform procedure:
•
Scan button is continually depressed
•
Probe slowly moved across forehead
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Temporal Artery Thermometer,
cont.
–
Probe sensor scans the forehead for heat given
off by temporal artery
–
Probe sensor captures highest temperature:
peak temperature
1) Represents the temperature given off by the
temporal artery (body temperature)
–
Probe sensor also measures ambient
temperature: surrounding air temperature
1) Small heat loss from the forehead due to
cooling by ambient temperature.
–
Thermometer automatically corrects for any
effect from ambient temperature
1) Displays an accurate body temperature
reading
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Temporal Artery Thermometer,
cont.
d. Avoiding Errors
•
Sweating of the forehead: causes inaccurate
temperature reading
•
Causes skin of forehead to cool: results in
falsely low temperature reading
•
Occurs when:
– A fever breaks
– Skin is clammy
1) Sweating may not be readily visible
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Temporal Artery Thermometer,
cont.
•
To avoid problem:
– Temperature of neck area behind earlobe is
measured (after scanning forehead)
1) Less affected by sweating than forehead
– During sweating: arteries behind the
earlobe dilate
1) Results in a constant, steady flow of
blood
2) Provides an accurate measurement of
body temperature when patient is
sweating
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Temporal Artery Thermometer,
cont.
– If patient's forehead has cooled from
sweating
1) Temperature behind earlobe
automatically registers as peak
temperature
2) Overrides forehead temperature
– Area behind earlobe does not normally
provide an accurate body temperature
measurement
1) Only supercedes the forehead
measurement when patient is sweating
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Temporal Artery Thermometer,
cont.
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Temporal Artery Thermometer,
cont.
e. Care and Maintenance
•
Store in clean, dry area
•
Protect from:
– Extremes in temperature
– Direct sunlight
– Dust
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Temporal Artery Thermometer,
cont.
e. Care and Maintenance
•
Clean casing periodically
– Damp cloth moistened with disinfectant
– Never splash water on or immerse the unit
in water
1) Could damage the thermometer
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Temporal Artery Thermometer,
cont.
•
Probe lens must be clean and shiny
– Dirty lens: Falsely low reading
– To clean lens:
1) Wipe with alcohol wipe
2) Immediately wipe dry with cotton-tipped
applicator stick
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Temporal Artery Thermometer,
cont.
f. Temporal Artery Thermometer Guidelines
•
Operating environmental temperature: 60º to
104º F
•
Do not take temperature over scar tissue, open
sores or abrasions
•
Make sure the side of the head to be measured
is exposed to the environment
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Temporal Artery Thermometer,
cont.
•
A falsely low temporal artery reading can result
from:
– A dirty probe lens
– Sweating of the forehead
1) Earlobe measurement becomes
overriding temperature reading
– Scanning the forehead too quickly.
– Not keeping the button depressed
1) While scanning forehead and area
behind the earlobe
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Chemical Thermometer
6. Chemical Thermometers
a. Contain chemicals that are heat-sensitive
b. Primarily used by patients at home
c. Less accurate than other thermometers
d. Store in cool area (below 86° F)
e. Do not expose to direct sunlight
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Chemical Thermometer, cont.
•
Disposable Chemical
Single-Use
Thermometers
– Contain small
chemical dots
that change color
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Chemical Thermometer, cont.
– Wrapper is peeled back to expose handle
– Thermometer is inserted under patient's
tongue (usually 60 seconds)
– Dots are observed for change in color
– Read by noting the highest reading among
dots that have changed color
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Chemical Thermometer, cont.
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Chemical Thermometer, cont.
•
Temperature-Sensitive Strips
– Reusable plastic strip
– Contains heat-sensitive crystals
– Placed on forehead and held in place until
color stops changing (generally 15 seconds)
– Results are read by:
1) Observing color change
2) Noting the corresponding temperature
indicated on strip
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Chemical Thermometer, cont.
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Pulse
Mechanism of the Pulse
1. When the left ventricle of the heart
contracts: blood is forced into the aorta
a. Aorta: major trunk of the arterial system
•
Aorta is already filled with blood
•
Must expand to accept blood from left ventricle
•
Creates a pulsating wave that travels from the
aorta through the walls of the arterial system
•
Wave is known as the pulse
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Mechanism of the Pulse, cont.
2. Pulse rate is measured by counting
number of "taps" or beats per minute
3. Heart rate is determined by taking pulse
rate
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Factors Affecting Pulse Rate
1. Age: As age increases, pulse rate decreases
a. Children have a faster pulse rate than
adults
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Factors Affecting Pulse Rate, cont.
2. Gender: Women tend to have faster pulse
rates than men
3. Physical activity: Increases pulse rate
temporarily
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Factors Affecting Pulse Rate, cont.
4. Emotional states: Increase pulse rate
temporarily
a. Anxiety
b. Fear
c. Excitement
d. Anger
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Factors Affecting Pulse Rate, cont.
5. Metabolism: Increased body metabolism
increases pulse rate
a. Example: During pregnancy
6. Fever: Increases pulse
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Factors Affecting Pulse Rate, cont.
7. Medications: May increase or decrease pulse
a. Examples:
•
Digitalis: decreases pulse
•
Epinephrine: increases pulse
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Pulse Sites
1. Pulse felt most strongly
when superficial artery
held against a firm
tissue (bone)
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Radial Pulse
2. Radial (radial artery)
a. Most common site
b. Located in a groove on the inner aspect of
the wrist just below the thumb
c. Easily accessible
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Radial Pulse, cont.
d. Used by individuals monitoring their own
heart rate:
•
Athletes
•
Patients taking heart medications
•
Individuals starting exercise program
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Radial Pulse
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Apical Pulse
3. Apical (apex of the heart)
a. Stronger beat: more easily heard than other
pulse sites
b. Should be taken if:
•
Having difficulty feeling radial pulse
•
Pulse is abnormally slow or rapid
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Apical Pulse, cont.
c. Often used for infants and children
up to 3 years
•
Other sites are difficult to palpate
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Apical Pulse, cont.
d. Is measured using a stethoscope
•
Chestpiece placed over apex of heart
– Location: Fifth intercostal space at left
midclavicular line
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Brachial Pulse
4. Brachial (brachial artery)
a. Located in antecubital space
•
Location: space at the front of the elbow
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Brachial Pulse, cont.
b. Used to:
•
Take blood pressure (BP)
•
Measure pulse in infants during
cardiac arrest
•
Assess circulation to lower arm
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Ulnar Pulse
5. Ulnar
a. Location: little finger
side of the wrist
b. Used to assess
circulation to hand
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Temporal Pulse
6. Temporal
a. Location: front of
ear just below eye
level
b. Used when radial is
not accessible
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Carotid Pulse
7. Carotid
a. Location: anterior side of
neck
•
Slightly to one side of midline
b. Best site to find a pulse
quickly
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Carotid Pulse
c. Used to:
•
Measure pulse in children and
adults during cardiac arrest
•
Monitor pulse during exercise
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Femoral Pulse
8. Femoral
a. Location: middle of the groin
b. Used to:
•
Measure pulse in infants, children,
and adults during cardiac arrest
•
Assess circulation to lower leg
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Popliteal Pulse
9. Popliteal
a. Location: back of the knee
b. Used to:
•
Measure BP when brachial not
accessible
•
Assess circulation to lower leg
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Posterior Tibial
10.Posterior tibial
a. Location: inner space of
ankle, posterior to ankle
bone
b. Used to assess circulation
to foot
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Dorsalis Pedis Pulse
11. Dorsalis pedis
a. Location: upper surface of
foot between first and
second metatarsal bones
b. Used to assess circulation
to foot
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Assessment of Pulse
1. Purpose of
measuring pulse
a. Establish patient's
baseline pulse rate
b. Assess pulse
following special
procedures,
medications, or
disease processes
that affect the heart
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Assessment of Pulse, cont.
2. Palpation used to locate pulse (except
for apical site)
a. Apply moderate pressure with the pads of
the three middle fingers
b. Use of excessive pressure: can obstruct
pulse
c. Too little pressure: may not be able to
detect pulse
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Assessment of Pulse, cont.
d. Do not use thumb: has a pulse of its own
•
Would result in measurement of MA's pulse
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Assessment of Pulse, cont.
3. Assessment of pulse includes:
a. Pulse rate
b. Rhythm
c. Volume
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Pulse Rate
1. Number of heartbeats in 1 minute
a. Measured in beats per minute (bpm)
2. Normal adult range: 60 to 100 bpm
a. Average falling between 70 and 80 bpm
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Pulse Rate, cont.
3. Tachycardia: An abnormally fast heart rate of
more than 100 bpm
a. Occurs during:
•
Hemorrhaging
•
Heart disease
•
Normally during vigorous exercise
•
Strong emotional states
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Pulse Rate, cont.
4. Bradycardia: An abnormally slow heart rate
falling below 60 bpm
a. Normally occurs:
•
During sleep
•
Trained athlete
•
Some medications
5. If patient exhibits
tachycardia/bradycardia during radial
pulse measurement:
a. Measure patient's apical pulse
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Pulse Rhythm and Volume
1. Pulse rhythm: time interval between
heartbeats
a. Normal rhythm: same interval between
beats
b. Dysrhythmia: unequal or irregular intervals
between beats
•
Also termed arrhythmia
•
Physician may order:
– Apical-radial pulse
– Electrocardiogram
– Holter monitoring
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Pulse Rhythm and Volume, cont.
2. Apical-radial pulse
a. Performed to determine if a pulse deficit is
present
b. Taking an apical-radial pulse
•
Measuring the apical pulse at the same time as
the radial pulse
– For one full minute
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Pulse Rhythm and Volume, cont.
c. Pulse deficit: Radial pulse rate is less than the
apical pulse rate
•
Example:
– One medical assistant measures an apical
pulse rate of 88 bpm
– Another medical assistant simultaneously
measures a radial pulse rate of 76 bpm
– Results in a pulse deficit of 12 beats
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Pulse Rhythm and Volume, cont.
•
Means that not all of the heartbeats are reaching
the peripheral arteries
•
Caused by an inefficient contraction of the heart
– Not strong enough to transmit a pulse wave
to peripheral pulse site
•
Frequently occurs with atrial fibrillation
(dysrhythmia)
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Pulse Rhythm and Volume, cont.
3. Pulse volume: strength of the heartbeat
a. Amount of blood pumped into aorta by each
contraction
•
Should remain constant
b. Normal pulse feels strong and full
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Pulse Rhythm and Volume, cont.
c. Thready pulse: blood volume decreases
•
Pulse feels weak
d. Bounding pulse: blood volume increases
•
Pulse feels extremely strong and full
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Pulse Rhythm and Volume, cont.
4. Record abnormalities in rhythm or
volume
5. Normal pulse: Record as regular and
strong
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Respiration
Mechanism of Respiration
1. Purpose of respiration
a. Exchange of oxygen (O2) and carbon
dioxide (CO2) between the atmosphere and
blood
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Mechanism of Respiration, cont.
2. Divided into two phases:
a. Inhalation
•
Diaphragm descends
•
Lungs expand
•
Causes air containing O2 to move into lungs
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Inhalation and Exhalation
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Mechanism of Respiration, cont.
b. Exhalation
•
Diaphragm ascends
•
Lungs return to original state
•
Causes air containing CO2 to be expelled (see
Figure 4-11)
3. One complete respiration: one inhalation
and one exhalation
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Inhalation and Exhalation
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Mechanism of Respiration, cont.
4. Classified as:
a. External respiration: exchange of O2 and
CO2 between alveoli and blood
•
Alveoli: Thin-walled air sacs of the lungs in
which the exchange of O2 and CO2 takes place
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Mechanism of Respiration, cont.
•
Blood located in small capillaries:
– Comes in contact with alveoli
– Picks up oxygen
– Carries it to the cells of the body
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Mechanism of Respiration, cont.
b. Internal respiration: exchange of O2 and CO2
between body cells and blood
•
O2 is given off to the cells
•
CO2 is picked up
– Transmitted as a waste product to lungs
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Control of Respiration
1. Involuntary respiration
a. Controlled by medulla oblongata
b. Buildup of CO2 sends message to medulla
•
Triggers respiration to occur automatically
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Control of Respiration, cont.
2. Voluntary respiration
a. Person can control (e.g., singing, talking)
b. Breath can only be held a certain length of
time
•
Medulla stimulated: causes respiration to occur
involuntarily
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Assessment of Respiration
1. Measure respiration without patient's
knowledge
a. Patient can control respiration
2. Ideal time: after pulse is taken
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Respiratory Rate
1. Normal adult range: 12 to 20
respirations per minute
2. Ratio of 1 respiration for every 4 pulse
beats
a. Example:
•
If respiratory rate is 18/minute
•
Pulse rate would be 72 bpm
•
(4 ×18 = 72)
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Respiratory Rate, cont.
3. Tachypnea: abnormal increase of more than
20 breaths/minute
4. Bradypnea: abnormal decrease of fewer than
12 breaths/minute
3. Factors that affect respiratory rate
a. Age: As age increases, respiratory rate
decreases
•
Respiratory rate of a child: faster than adult
(see Table 4-5)
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Respiratory Rate, cont.
b. Physical activity: increases rate temporarily
c. Emotional state: increases rate
d. Fever: increases rate
e. Medications: increase or decrease rate
(depends on type of medication)
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Rhythm and Depth of Respiration
1. Rhythm should be:
a. Even and regular
b. Pauses between inhalation and exhalation
should be equal
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Rhythm and Depth of Respiration,
cont.
2. Depth of respiration: amount of air
inhaled or exhaled
a. Described as
•
Normal: depth is the same
•
Deep: large volume of air is inhaled and exhaled
•
Shallow: exchange of small volume of air
b. Determined by observing the amount of
movement of chest
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Rhythm and Depth of Respiration,
cont.
3. Eupnea: normal respiration
a. Rate: 12 to 20 breaths/minute
b. Rhythm: even and regular
c. Depth: normal
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Rhythm and Depth of Respiration,
cont.
4. Hyperpnea: abnormal increase in rate
and depth
a. Patient exhibits very deep, rapid, and
labored breathing
b. Occurs normally in exercise
c. Occurs abnormally in fever and pain
d. Also occurs with any condition in which
supply of oxygen is inadequate
•
Heart disease
•
Lung disease
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Rhythm and Depth of Respiration,
cont.
5. Hyperventilation: abnormally fast and
deep breathing
a. Usually associated with acute anxiety (e.g.,
hysteria, panic attacks)
b. Individual is "overbreathing"
c. Causes dizziness and weakness
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Rhythm and Depth of Respiration,
cont.
6. Hypopnea: abnormal decrease in rate
and depth
a. Depth: Approximately half of normal
respirations
b. Often occurs with sleep disorders
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Color of the Patient
1. Observe color while taking respirations
2. Hypoxia: A reduction in the oxygen
supply to the tissues
a. Results in cyanosis
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Color of the Patient, cont.
3. Cyanosis: bluish coloration of skin and
mucous membranes
a. First observed in nailbeds and lips
•
Blood vessels lie close to the skin in these areas
b. Occurs in patients with:
•
Advanced emphysema
•
Cardiac arrest
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Color of the Patient, cont.
4. Apnea: temporary absence of respirations
a. May occur during sleep
•
Known as sleep apnea
b. Serious if breathing ceases for more than
4 to 6 breaths/minute
•
Patient could suffer brain damage and death
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Respiratory Abnormalities
1. Dyspnea: difficulty breathing or shortness of
breath
a. Normal during vigorous exercise
b. Abnormal in patients with:
•
Emphysema
•
Asthma
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Respiratory Abnormalities, cont.
2. Orthopnea: The condition in which breathing
is easier when an individual is in a sitting or
standing position
a. Occurs with disorders of heart and lungs:
•
Asthma
•
Emphysema
•
Pneumonia
•
Congestive heart failure
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Breath Sounds
1. Caused by air moving through
respiratory tract
2. Normal breath sounds: quiet and barely
audible
3. Adventitious sounds: abnormal breath
sounds
a. Indicate presence of respiratory disorder
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Abnormal Breath Sounds
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What Would You Do?
What Would You Not Do?
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What Would You Do?
What Would You Not Do?
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Pulse Oximetry
1. Painless and noninvasive procedure
2. Used to measure oxygen saturation of
hemoglobin in arterial blood
a. Hemoglobin
•
Complex compound found in red blood cells
•
Function: transports oxygen
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Pulse Oximetry, cont.
3. Pulse oximetry provides information on:
a. Cardiorespiratory status
•
Amount of oxygen being delivered to tissues
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Pulse Oximetry, cont.
4. Pulse oximeter
a. Computerized device
b. Measures oxygen saturation
c. Consists of cliplike probe connected to a
monitor
d. Also measures pulse rate in b/m
•
Beep is emitted with each pulse beat
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Pulse Oximetry, cont.
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Mechanism of Action
1. Probe attached to peripheral pulsating
capillary bed (fingertip)
2. Light emitting diode (LED):
a. Transmits infrared light and red light
through tissues to a
photodetector (light
detector)
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Mechanism of Action, cont.
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Mechanism of Action, cont.
3. Bright red hemoglobin:
a. High oxygen content (oxygen-rich)
b. Absorbs infrared light from LED
4. Dark red hemoglobin:
a. Low in oxygen (oxygen-poor)
b. Absorbs red light from LED
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Mechanism of Action, cont.
5. Computer of oximeter:
a. Calculates light transmitted from oxygenrich and oxygen-poor hemoglobin (hgb)
•
From this ratio: determines oxygen saturation
of hgb
– Measurement converted to a percentage
– Displayed on screen of monitor
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Mechanism of Action, cont.
6. SpO2: Saturation of peripheral oxygen
a. Pulse oximeter measures oxygen saturation
of peripheral capillaries
b. Abbreviation used when a pulse oximeter is
used to measure oxygen saturation level
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Mechanism of Action, cont.
7. SaO2: Saturation of arterial oxygen
a. Arterial blood gas (ABG) analysis
•
More complete, but invasive measurement of
oxygen saturation
•
Requires drawing a blood specimen from an
artery
b. Abbreviation (SaO2 ) used when ABG
analysis is used to measure oxygen
saturation level
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Interpretation of Results
1. Pulse oximetry reading: represents
percentage of hgb saturated with oxygen
a. Each molecule of hgb: can carry four
oxygen molecules
•
100 molecules of hgb: fully saturated with
oxygen
– Would be carrying 400 molecules of oxygen
– Oxygen saturation reading: 100%
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Interpretation of Results, cont.
•
100 molecules of hgb: carrying 360 molecules
of oxygen
– Oxygen saturation reading: 90%
b. The more hgb saturated with oxygen: the
higher the oxygen saturation
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Interpretation of Results, cont.
2. Oxygen saturation of healthy individuals:
95% to 99%
a. Air is only 21% saturated with oxygen
•
Unusual for hgb to be 100% saturated with
oxygen
•
Patients on supplemental oxygen may have a
reading of 100%
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Interpretation of Results, cont.
b. Oxygen saturation below 95%:
•
Results in inadequate amount of oxygen
reaching tissues
•
Some patients with chronic pulmonary disease
are able to tolerate lower saturation levels
c. Oxygen saturation between 85% and 90%:
respiratory failure resulting in tissue
damage
d. Oxygen saturation of 75%: cyanosis
appears
e. Oxygen saturation below 70%: lifethreatening
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Interpretation of Results, cont.
3. Hypoxemia: decrease in the oxygen
saturation of the blood
a. Can lead to hypoxia
4. Hypoxia: a reduction in the oxygen supply to
tissues
a. If not treated: tissue damage and death
b. Symptoms: headache, mental confusion,
nausea, dizziness, shortness of breath,
tachycardia
c. Tissues most sensitive to hypoxia: brain,
heart, pulmonary vessels and liver
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Purpose of Pulse Oximetry
1. Performed on patients c/o respiratory
problems (e.g., dyspnea)
2. Decreased SpO2 reading (along with
further testing and clinical signs and
symptoms)
a. Assists physician in diagnosis and
treatment
•
May include drug therapy and oxygen therapy
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Purpose of Pulse Oximetry, cont.
3. Decreased SpO2 value (hypoxemia)
caused by:
a. Acute pulmonary disease (pneumonia)
b. Chronic pulmonary disease (emphysema,
asthma, bronchitis)
c. Cardiac problems (congestive heart failure,
coronary artery disease)
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Purpose of Pulse Oximetry, cont.
4. Pulse oximetry used to assess:
a. Effectiveness of oxygen therapy
b. Patient tolerance to activity
c. Effectiveness of treatment such as
bronchodilators
d. Patient tolerance to analgesia and sedation
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Purpose of Pulse Oximetry, cont.
5. Most often used for 'spot-check'
measurement of oxygen saturation
(single measurement)
6. Occasionally used for short-term
continuous monitoring:
a. Patient experiencing an asthmatic attack
b. Sedated patient during minor office surgery
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Components of the Pulse Oximeter
1. Handheld pulse oximeter: used by most
offices
a. Portable and lightweight
b. Usually battery operated
2. Stand-alone oximeter
a. Used in a hospital setting
•
Continuous bedside monitoring of oxygen
saturation
3. Pulse oximeter also measures pulse rate
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Monitor
1. Contains controls, indicators and
displays
a. On/Off Control: Turns oximeter on and off
b. SpO2% Display: Digital display of oxygen
saturation
•
Expressed as a percent
•
Updated with each pulse beat
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Monitor, cont.
c. Pulse Rate Display: Indicates pulse rate in
b/m
•
Updated with each pulse beat
•
Oximeter emits a constant-pitch audible beep
with each pulse beat
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Monitor, cont.
d. Pulse Strength Bar Graph Indicator: Display
of pulse strength
•
Consists of a segmented display of bars
•
Stronger the pulse: the more segments light up
e. Pulse Search Indicator: Lights when oximeter
is searching for pulse
f. Adjustable Volume Control: Adjusts the beep
that sounds with each pulse beat
•
Settings: high, low and off
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Monitor, cont.
g. Low Battery Indicator: Warns that battery is
getting low
•
Lights up and sounds an alarm when 30 minutes
of battery use remain
h. Alarm Messages: Audible beeps that indicate a
problem or condition which may affect the reading
•
Must not be ignored
•
Must be corrected before continuing
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Monitor, cont.
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Monitor, cont.
2. Power-on self test (POST): automatically
occurs when oximeter is turned on
a. Takes approximately 3 to 5 seconds
b. Oximeter checks its internal systems to
make sure functioning properly
c. If problem detected: alarm sounds and
monitor displays an error code
•
Refer to troubleshooting section of user manual
– For interpretation of code and action to take
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Monitor, cont.
3. Oximeter begins searching for a pulse
a. Pulse search indicator lights up
b. Takes several seconds to:
•
Locate a pulse
•
Calculate and display SpO2 reading
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Monitor, cont.
4. Oximeter is unable to detect pulse or
pulse is too weak to provide necessary
data needed to calculate oxygen
saturation:
a. Alarm sounds
b. Oximeter may automatically shut off
c. Reposition probe or move probe to another
finger
•
Perform procedure again
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Probes
1. Reusable or disposable
a. Most offices use reusable clip-on probes
•
Convenient to use
•
Easy to apply
•
More susceptible to inaccurate readings from
patient movement
•
Must be cleaned and disinfected after use
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Probes, cont.
b. Disposable probes
•
Expensive to use
•
Used for long-term monitoring of oxygen
saturation in hospital
•
Made of adhesive bandage-like material
•
Discarded after use
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Probes, cont.
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Probes, cont.
2. Handle reusable probe carefully
a. Hitting probe against hard object or
dropping it: may damage it
b. Use probe designed for oximeter being
used
•
Mixing probes from different manufacturers: can
result in inaccurate reading
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Probes, cont.
3. Probe must be attached to a peripheral
site that is:
a. Highly vascular
b. Skin is thin
•
Most common site: fingertip
•
Other sites: toe and earlobe
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Probes, cont.
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Probes, cont.
4. Cable connects probe to monitor
a. Probe may be permanently attached to
cable
b. Or may be a separate device
•
Requires connection to the cable
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Probes, cont.
c. Never lift or carry monitor by the cable
•
Could damage the cable connections
•
Monitor could fall on floor or on patient
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Factors Affecting Pulse Oximetry
1. Fingernail polish or artificial nails:
a. Opaque coating on fingernail: may result in
falsely low reading
•
Interferes with light transmission through finger
•
The darker the coating: more likely SPO2
reading is affected
– Blue, black, and green nail polishes: cause
the most problems
•
Remove nail polish with acetone or fingernail
polish remover
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Factors Affecting Pulse Oximetry,
cont.
1. Fingernail polish or artificial nails:
a. Patient has artificial fingernails
•
Use another site such as the earlobe or toe
b. Avoid areas with bruises, burns, stains, or
tattoos
c. Darkly pigmented skin and jaundice
•
Do not affect reading
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Factors Affecting Pulse Oximetry,
cont.
2. Ambient (surrounding) light shining
directly on probe:
a. Examples: bright fluorescent light, direct
sunlight, overhead examination light
b. May result in inaccurate reading
c. Ambient light may be picked up by
photodetector
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Factors Affecting Pulse Oximetry,
cont.
d. Corrected by:
•
Turning off light
•
Moving probe away from light source
•
Covering probe with opaque material
(washcloth)
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Factors Affecting Pulse Oximetry,
cont.
3. Patient movement:
a. Common cause of inaccurate reading
b. Motion affects ability of light to travel from
LED to photodetector
c. Prevents probe from picking up pulse signal
d. Instruct patient to remain still during
procedure
e. Occasionally patient movement cannot be
eliminated (tremors of hands)
•
Measure at a site less affected by motion (toe or
earlobe)
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Factors Affecting Pulse Oximetry,
cont.
4. Incorrect positioning of probe:
a. Light is transmitted from LED to
photodetector
•
Must be aligned directly opposite to each other
– Automatically occurs when probe is applied
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Factors Affecting Pulse Oximetry,
cont.
b. Alignment of probe may not be possible
with:
•
Patients with very small fingers (such as a thin
patient or a child)
•
Patients with very large fingers (such as an
obese patient)
– Use another site: earlobe
– Pediatric probes can be used with thin
patients or children
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Factors Affecting Pulse Oximetry,
cont.
5. Poor peripheral blood flow:
a. Pulse oximeter works best when there is a
good strong pulse in finger to which probe
is applied
b. Poor blood flow may cause pulse to be so
weak that oximeter cannot obtain a reading
c. Conditions resulting in poor blood flow:
•
Peripheral vascular disease
•
Vasoconstrictor medications
•
Severe hypotension
•
Hypothermia
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Factors Affecting Pulse Oximetry,
cont.
5. Poor peripheral blood flow:
d. Use earlobe: less affected by decreased
blood flow
e. Patients with cold fingers (but not
hypothermic)
•
May have enough constriction that it interferes
with obtaining a reading
•
Ask patient to warm finger by rubbing hands
together
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Factors Affecting Pulse Oximetry,
cont.
f. Never attach probe to:
•
Finger of an arm to which an automatic blood
pressure cuff is applied
– Blood flow to finger cut off when cuff
inflates: results in loss of pulse signal
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Cleaning and Maintenance
1. Monitor and cable
a. Clean periodically with damp cloth and
nonabrasive cleaner
•
Do not allow water or detergent to run into
monitor
– Could damage internal components
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Cleaning and Maintenance, cont.
2. Probe
a. Clean periodically with soft cloth moistened
in water and mild detergent
•
Removes dirt and grime
– Could interfere with light transmission
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Cleaning and Maintenance, cont.
•
Disinfect by wiping thoroughly with isopropyl
alcohol and allow to dry
•
Never soak or immerse in liquid solution
– Would damage probe
b. Probe is heat-sensitive: cannot be
autoclaved
c. Store pulse oximeter: at room temperature
in a dry environment
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Blood Pressure
Mechanism of Blood Pressure
1. Blood pressure: Measurement of force exerted
by the blood on the walls of the arteries
2. Systole: phase in the cardiac cycle in which the
ventricles contract
a. Blood is pushed out of heart and into aorta
and pulmonary artery, exerting pressure on
their walls
3. Systolic pressure: point of highest pressure on
arterial walls
a. Recorded during systole
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Mechanism of Blood Pressure, cont.
4. Diastole: phase in cardiac cycle in which the
heart relaxes between contractions
5. Diastolic pressure: point of lesser pressure
on arterial walls
a. Recorded during diastole
b. Pressure is lower because the heart is
relaxed
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Interpretation of Blood Pressure
1. Blood pressure: abbreviated BP
2. Measurement expressed as a fraction:
a. Numerator: systolic pressure
b. Denominator: diastolic pressure
3. Measured in millimeters of mercury (mm
Hg)
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Interpretation of Blood Pressure,
cont.
4. New guidelines from NHLBI:
a. Normal BP: Less than 120/80 mm Hg
b. Prehypertension:
•
Sustained systolic: 120 to 139 mm Hg
OR
•
Sustained diastolic: 80 to 89 mm Hg
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Interpretation of Blood Pressure,
cont.
5. BP should be taken at every office visit
a. Several readings taken on different
occasions
•
Provide a good index of baseline BP
b. Rise or fall of 20 to 30 mm Hg in baseline BP
is significant
•
Even if still in normal range
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Interpretation of Blood Pressure,
cont.
6. Hypertension: high blood pressure
a. Hyptertension Stage I:
•
Sustained systolic: 140 to 159 mm Hg
OR
•
Sustained diastolic: 90 to 99 mm Hg
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Interpretation of Blood Pressure,
cont.
b. Hypertension Stage 2:
•
Sustained systolic: 160 or higher mm Hg
OR
•
Sustained diastolic: 100 mm Hg or higher
c. Caused by excessive pressure on arterial
walls
d. Most common condition that causes an
abnormal BP reading
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Interpretation of Blood Pressure,
cont.
7. Hypotension: low blood pressure
a. Reduced pressure on arterial walls
b. BP reading below 95/60 mm Hg
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Interpretation of Blood Pressure,
cont.
8. Pulse Pressure: difference between systolic
and diastolic pressures
a. Determined by subtracting smaller number
from larger number
•
Example: If BP is 110/70 mm Hg, pulse pressure
is 40 (110 to 70 mm Hg)
b. Normal range: between 30 and 50 mm Hg
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Factors Affecting Blood Pressure
1. Age: as age increases BP gradually increases
*In Children and adolescents, hypertension is defined as blood pressure that is, on repeated measurement,
at the 95th percentile or greater adjusted for age, height, and gender (NHBPEP, 1997).
From the National High Blood Pressure Education Program (NHBPEP); National Heart, Lung, and Blood Institute; National Institutes of Health;
The seventh report of the Joint National Committees on Detection, Evaluation, and Treatment of High Blood Pressure, JAMA 239:2560, 2003.
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Factors Affecting Blood Pressure,
cont.
2. Gender: after puberty women have a lower BP
than men of same age
a. After menopause: BP is higher in women
3. Diurnal variations: BP is lower in morning
and higher in afternoon
a. During sleep:
•
Decreased metabolism
•
Decreased physical activity
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Factors Affecting Blood Pressure,
cont.
4. Emotional states: increase BP
a. Calm patient before taking BP
5. Exercise: temporarily increases BP
a. If a patient has been involved in physical
activity
•
Allow patient to rest 20 to 30 minutes before
taking BP
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Factors Affecting Blood Pressure,
cont.
6. Body position: BP varies based on position
a. Make a notation if position is other than
sitting
•
L: lying
•
St: standing
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Factors Affecting Blood Pressure,
cont.
7. Medications: may increase or decrease BP
(depending on type of medication)
a. Important to record prescription and overthe-counter medications in patient's chart
8. Also increases BP
a. Recent meal
b. Smoking
c. Bladder distention
d. Pain
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Assessment of Blood Pressure
1. Equipment needed:
a. Stethoscope
b. Sphygmomanometer
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Stethoscope
2. Stethoscope: An instrument for amplifying
and hearing sounds produced by the body
a. Consists of four parts:
•
Earpieces
•
Sidepieces (binaurals)
•
Plastic or rubber tubing
•
Chestpiece
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Stethoscope
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Stethoscope, cont.
3. Stethoscope Chestpiece
a. Types
•
Diaphragm: large flat disc
– Most useful for hearing high-pitched sounds
1) Lung sounds
2) Bowel sounds
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Stethoscope, cont.
•
Bell: bowl-shaped appearance
– Most useful for hearing low-pitched sounds
1) Heart sounds
2) Vascular system sounds
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Chestpiece
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Stethoscope, cont.
b. If chestpiece consists
of both:
•
Must rotate desired
piece into position
before use
– Otherwise cannot
hear sounds
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Sphygmomanometer
1. Sphygmomanometer: An instrument for
measuring arterial blood pressure
1. Consists of:
a. Manometer: scale for registering the
pressure of air in the bladder
b. Inner inflatable bladder surrounded by a
covering (cuff)
c. Pressure bulb with a control valve: To
inflate and deflate inner bladder
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Sphygmomanometer, cont.
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Sphygmomanometer, cont.
3. Aneroid sphygmomanometer
a. Gauge with a round scale calibrated in
millimeters
•
Needle points to calibrations
•
Needle must be at zero before taking BP
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Sphygmomanometer, cont.
b. MA should be no farther than 3 feet from the
scale of the manometer
•
To ensure an accurate reading
c. Position manometer for direct viewing
d. Recalibrate manometer every year to
ensure accuracy
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Sphygmomanometer, cont.
4. Mercury sphygmomanometer
a. Vertical tube filled with mercury and calibrated
in millimeters
b. More accurate than aneroid
c. Use is discouraged; mercury is a hazardous
chemical
d. MA should be no further than 3 feet from scale
e. Mercury must be on zero before taking BP
f. Inflation of inner bladder: causes mercury to
rise in tube
g. BP is read at the top of the meniscus
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Mercury Sphygmomonometer
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Cuff Sizes
1. Variety of sizes: measured in
centimeters (cm)
2. Size of cuff: refers to inner bladder
rather than outer covering
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Cuff Sizes, cont.
3. Inner bladder of cuff should:
a. Encircle 80% of arm circumference
b. Be wide enough to cover two thirds of
distance from axilla to antecubital space
•
Cuff must fit properly to ensure an accurate
reading
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Cuff Sizes, cont.
4. Child cuff often used for adult with thin
arms
5. Adult cuff used for average-sized adult
arm
6. Thigh cuff used for thigh or adults with
large arms
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Cuff Sizes, cont.
7. If cuff too small: reading is falsely high
8. If cuff too large: reading is falsely low
9. Center of inflatable bag should be
directly over brachial artery
a. To allow complete compression of the
brachial artery
10.Velcro is used to secure the cuff
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Korotkoff Sounds
1. Used to determine systolic and diastolic
BP readings
a. When bladder of the cuff is inflated:
•
Brachial artery is compressed
•
No audible sounds heard
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Korotkoff Sounds, cont.
b. As cuff is deflated:
•
Sounds become audible
•
When blood flows freely, sounds can no longer
be heard
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Korotkoff Sounds, cont.
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Korotkoff Sounds, cont.
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Korotkoff Sounds, cont.
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Guidelines to Prevent Errors in
Blood Pressure Measurement
1. Before BP instruct patient not to:
a. Consume caffeine
b. Use tobacco
•
For 30 minutes before BP
2. Patient should be seated in a quiet room
for at least 5 minutes before BP
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Guidelines to Prevent Errors in
Blood Pressure Measurement, cont.
3. Always use proper cuff size
a. Cuff that is too small:
•
May come loose as the cuff is inflated
•
Reading may be falsely high
b. Cuff that is too large
•
Reading may be falsely low
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Guidelines to Prevent Errors in
Blood Pressure Measurement, cont.
c. Inner inflatable bladder of
cuff should:
•
Encircle at least 80% of
patient's arm
•
Cover two thirds of distance
from axilla to antecubital
space
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Guidelines to Prevent Errors in
Blood Pressure Measurement, cont.
4. Never take BP over clothing
a. Interferes with ability to hear Korotkoff
sounds
•
Could result in inaccurate BP
b. Roll up patient's sleeve approx 5 inches
above elbow
•
If sleeve is too tight after being rolled up:
remove arm from sleeve
– Tight sleeve: causes partial compression of
brachial artery
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Guidelines to Prevent Errors in
Blood Pressure Measurement, cont.
5. Position patient's arm properly
a. At heart level
•
Well supported
•
Palm facing upward
b. If above heart level: BP may be falsely low
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Guidelines to Prevent Errors in
Blood Pressure Measurement, cont.
6. Avoid extraneous sounds
from cuff: interferes with
accurate measurement
a. Position cuff 1 to 2 inches
above bend in elbow
b. Prevents stethoscope from
touching cuff
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Guidelines to Prevent Errors in
Blood Pressure Measurement, cont.
7. Compress brachial artery completely
a. Center bladder of cuff directly over artery
to be compressed
•
Most cuffs: labeled with arrows indicating
center of bladder for right and left arms
b. Centering allows for complete compression
of the brachial artery
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Guidelines to Prevent Errors in
Blood Pressure Measurement, cont.
8. Apply equal pressure over brachial
artery
a. Apply cuff so that it fits smoothly and snugly
around patient's arm
•
Prevents bulging or slipping
•
Permits application of equal pressure over
brachial artery
b. Loose-fitting cuff: falsely high reading
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Guidelines to Prevent Errors in
Blood Pressure Measurement, cont.
9. Position earpieces
so you can hear
sounds clearly
a. Place in ears with
earpieces directed
slightly forward
•
Allows earpieces to
follow direction of
ear canal:
facilitates hearing
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Guidelines to Prevent Errors in
Blood Pressure Measurement, cont.
10.Avoid extraneous sounds from tubing
a. Tubing of stethoscope should hang freely
•
Do not permit to rub against any object
b. If tubing rubs against an object: extraneous
sounds may be picked up
•
Could interfere with accurate measurement
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Guidelines to Prevent Errors in
Blood Pressure Measurement, cont.
11.Position chestpiece
properly
a. Palpate brachial pulse to
provide good positioning
of chestpiece over
brachial artery
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Guidelines to Prevent Errors in
Blood Pressure Measurement, cont.
b. Place chestpiece firmly, but gently, over
brachial artery
•
Assists in transmitting clear and audible sounds
c. Do not allow chestpiece to touch cuff
•
To prevent extraneous sounds from being
picked up
– Could interfere with accurate measurement
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Guidelines to Prevent Errors in
Blood Pressure Measurement, cont.
12. Release pressure at a moderate steady
rate
a. 2 to 3 mm Hg per second:
to ensure an accurate BP
a. Releasing pressure too
quickly or too slowly
•
Could cause falsely low
systolic reading and falsely
high diastolic reading
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Guidelines to Prevent Errors in
Blood Pressure Measurement, cont.
13.Avoid venous congestion
a. If you need to take the blood pressure in the
same arm again
•
Wait 1 to 2 minutes
– Allows blood trapped in veins (venous
congestion) to be released
b. Venous congestion: can result in falsely
high systolic reading and a falsely low
diastolic reading.
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Guidelines to Prevent Errors in
Blood Pressure Measurement, cont.
14.Measure and record BP in both arms
during the initial assessment of a new
patient
a. May normally be a difference of 5 to 10 mm
Hg between the two arms
b. During return visits: BP should be
measured in the arm with higher initial
reading
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What Would You Do?
What Would You Not Do?
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What Would You Do?
What Would You Not Do?
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POSTTEST
True or False
1.
2.
3.
4.
5.
A temperature of 100° F is classified as a low-grade
fever.
The rectal site should not be used to take the
temperature of a newborn.
A tympanic membrane thermometer should not be
used to measure temperature on a patient who has a
normal amount of cerumen in the ear.
A temporal artery temperature reading is the same
as an oral reading.
Excessive pressure should not be applied when
measuring pulse because it could obstruct the pulse.
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POSTTEST, CONT.
True or False
6. A child has a faster pulse rate than an adult.
7. The normal respiratory rate of an adult ranges
between 10 and 18 respirations per minute.
8. The term used to describe a bluish discoloration of the
skin due to a lack of oxygen is hypoxia.
9. The oxygen saturation level of a healthy individual falls
between 85% and 90%.
10. When measuring blood pressure, the patient's arm
should be positioned above the level of the heart.
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