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Chapter 25
Assessment:
Respiratory System
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1
Structures and Functions of
Respiratory System (1 of 18)

Primary purpose: gas exchange


Transfer of oxygen (O2) and carbon dioxide (CO2)
between atmosphere and blood
Two parts (Fig. 25-1)


Upper respiratory tract
Lower respiratory tract
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2
Structures and Functions of
Respiratory System (2 of 18)
Fig. 25-1
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Structures and Functions of
Respiratory System (3 of 18)

Upper respiratory tract

Nose
• Warm, filter, humidify
Mouth
 Pharynx
 Epiglottis
 Larynx
 Trachea

• Carina—bifurcation
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4
Structures and Functions of
Respiratory System (4 of 18)

Lower respiratory tract
Bronchi
Bronchioles
 Alveolar ducts
 Alveoli



Lung lobes
• Right—3
• Left—2
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5
Structures and Functions of
Respiratory System (5 of 18)




Structures of the lower
airways
Trachea and bronchi—
anatomic dead space (VD);
no gas exchange
Bronchioles—smooth
muscle constricts and
dilates
Alveoli—terminal part of
respiratory tract; gases
exchange
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Structures and Functions of
Respiratory System (6 of 18)

Alveoli


Primary site for gas
exchange with
pulmonary capillaries
Pores of Kohn
Interconnections
between alveoli
 Allow air to pass; also
bacteria

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7
Structures and Functions of
Respiratory System (7 of 18)
Surfactant

Lipoprotein secreted by alveoli when stretched
Reduces surface tension to make alveoli less
likely to collapse

Atelectasis—collapsed alveoli

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Structures and Functions of
Respiratory System (8 of 18)

Blood supply

Pulmonary circulation—gas exchange
• Artery—deoxygenated blood from right ventricle
• Capillaries—exchange gases at alveoli
• Veins—return oxygenated blood to left atrium

Bronchial circulation
• Arteries—oxygen to bronchi and lung tissues
• Azygos vein—deoxygenated blood to superior vena
cava
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Structures and Functions of
Respiratory System (9 of 18)

Chest wall

Ribs and sternum

Mediastinum

Pleura
• Thoracic cage—protect lungs and heart
• Heart, aorta, and esophagus
• Parietal—chest cavity
• Visceral—lungs
• Intrapleural space: 20 to 25 mL fluid provides
lubrication; facilitates expansion
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10
Structures and Functions of
Respiratory System (10 of 18)

Chest wall

Diaphragm—major muscle of respiration
• Inspiration—contracts toward abdomen; increases
intrathoracic volume
• Works with intercostal and scalene muscles
• Innervated by right and left phrenic nerves; arise from
cervical vertebrae 3 to 5
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11
Structures and Functions of
Respiratory System (11 of 18)

Physiology of respiration

Oxygenation—O2 from atmosphere to organs and
tissues
• Oxygen dissolved in plasma = Partial pressure of
oxygen in arterial blood (PaO2); normal 80 to 100 mm
Hg
• Oxygen bound to hemoglobin = Arterial oxygen
saturation (SaO2); normal greater than 95%

Diffusion—O2 and CO2 exchange at alveolar-capillary
membrane; move from high to low concentration until
equal
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Structures and Functions of
Respiratory System (12 of 18)


Physiology of respiration
Ventilation
Inspiration and expiration occur due to intrathoracic
pressure changes and muscle action
 Expiration—passive

• Elastic recoil—lungs return to original size after
expansion
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Structures and Functions of
Respiratory System (13 of 18)


Physiology of respiration
Compliance—measures ease of lung expansion;
elasticity and elastic recoil



Decreased—hard for lungs to inflate
Increased—hard for lungs to recoil
Resistance—airflow impeded during inspiration
and/or expiration; altered airway diameter

Narrowed by constriction or secretions
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Structures and Functions of
Respiratory System (14 of 18)

Control of respiration

Medulla is respiratory center
• In brainstem
• Responds to chemical and mechanical signals
• Sends impulses from spinal cord and phrenic nerve to
respiratory muscles
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Structures and Functions of
Respiratory System (15 of 18)


Control of respiration
Chemoreceptors
Respond to changes in PaCO2 and pH in surrounding fluid
Central chemoreceptors—medulla


Increase H+ concentration—acidosis results in increased
RR and VT
 Decrease H+ concentration—alkalosis results in
increased RR and VT
 Increased PaCO2 results in increased H2CO3 resulting in
decreased pH of CSF resulting in increased RR
 Decreased PaCO2 results in decreased H2CO3 resulting
in increased pH of CSF resulting in decreased RR

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Structures and Functions of
Respiratory System (16 of 18)


Control of respiration
Chemoreceptors

Peripheral chemoreceptors—carotid bodies and aortic
bodies
• Respond to decreased PaO2, decreased pH, and
increased PaCO2
• Stimulate respiratory center to increase RR

COPD—chronically increased PaCO2 does not
stimulate increased RR; hypoxic drive
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Structures and Functions of
Respiratory System (17 of 18)


Control of respiration
Mechanical receptors
Located conducting upper airways, chest wall,
diaphragm, and alveolar capillaries
 Three types respond to stimuli

• Irritant
• Stretch—Hering-Breuer reflex
• j-receptors—juxtacapillary receptors
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Structures and Functions of
Respiratory System (18 of 18)


Respiratory defense mechanisms
Protect lungs
Filtration of air
Mucociliary clearance
 system -escalator
 Cough reflex
 Reflex bronchoconstriction
 Alveolar macrophages


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19
Gerontologic Considerations:
Effects of Aging on Respiratory
System

Structural changes

Defense mechanisms

Respiratory control


Reduced chest expansion and functional alveoli
Reduced immune function
More gradual responses to changes in O2 and CO2
levels
 See Table 25-2

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20
Assessment of Respiratory System
(1 of 16)

Health history and physical examination

Subjective data


Consider degree of respiratory distress
Important health information
• Past health history—respiratory, allergies, other body
systems
• Medications—prescription, OTC, Illicit, O2
• Surgery or other treatments
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Assessment of Respiratory System
(2 of 16)

Subjective data

Functional health patterns (Table 25-3)
• Health perception–health management pattern
Smoking history/exposure to smoke
Change in respiratory status; respiratory problems;
characteristics of cough and sputum; international travel
 Immunizations


• Genetic risk

Family history of cystic fibrosis, COPD, asthma
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22
Assessment of Respiratory System
(3 of 16)

Subjective data

Functional health patterns
• Nutritional–metabolic pattern

Weight changes; fluid intake
• Elimination pattern

Incontinence; constipation
• Activity–exercise pattern
Dyspnea limitations (Table 25-4)
Positions make better or worse
 ADLs


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23
Assessment of Respiratory System
(4 of 16)

Subjective data

Functional health patterns
• Sleep–rest pattern

Awakened during night; HOB increase; apnea; night
sweats
• Cognitive–perceptual pattern

Neurologic changes; pain with breathing
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Assessment of Respiratory System
(5 of 16)

Subjective data

Functional health patterns
• Self-perception–self-concept pattern
 Social interactions; body image; self-esteem
• Role–relationship pattern
Family, job, social life
Work—exposure to fumes, toxins, asbestos, coal, fibers,
or silica
 Hobbies—exposure to dust or allergens


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25
Assessment of Respiratory System
(6 of 16)

Subjective data

Functional health patterns
• Sexuality–reproductive pattern

Change in sexual activity; positions
• Coping–stress tolerance pattern

Anxiety-dyspnea cycle; support group or pulmonary
rehab referral
• Value-belief pattern

Adherence to treatment; explore constraints
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26
Assessment of Respiratory System
(7 of 16)

Objective data

Physical examination
• VS with pulse oximetry
• Nose

Patency, inflammation, deformity, symmetry, discharge
• Mouth and pharynx

Color lesions, masses, gums, dentition, bleeding
• Neck

Symmetry, tenderness, swollen nodes
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Assessment of Respiratory System
(8 of 16)

Objective data

Physical examination
• Thorax and lungs
Inspection
Palpation
 Percussion
 Auscultation


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28
Assessment of Respiratory System
(9 of 16)

Inspection
Appearance: position; evidence of respiratory distress
Shape, symmetry, and movement
 Respiratory rate, depth, and rhythm
 Skin and nails: cyanosis, clubbing


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29
Assessment of Respiratory System
(10 of 16)




Palpation
Tracheal position
Expansion
Fremitus
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10
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Assessment of Respiratory System
(11 of 16)
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31
Assessment of Respiratory System
(12 of 16)

Sequence of examination
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32
Assessment of Respiratory System
(13 of 16)

Percussion
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Assessment of Respiratory System
(14 of 16)

Percussion
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Assessment of Respiratory System
(15 of 16)

Auscultation: Three normal sounds
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35
Assessment of Respiratory System
(16 of 16)

Abnormal/adventitious breath sounds

Crackles
• Fine
• Coarse
Wheezes
Stridor
 Pleural friction rub



Abnormal voice sounds
Egophony
Bronchophony
 Whispered pectoriloquy


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Diagnostic Studies of Respiratory
System (1 of 10)

Pulse oximetry—SpO2 = 94% to 99%
• Nursing: Be aware of factors affecting accuracy
• See Tables 25-9 and 25-10

Arterial blood gases (ABG)
• Oxygenation and acid-base balance
• PaO2, PaCO2, pH, HCO3− , SaO2

See Table 25-11
• Nursing: No changes to O2 15 minutes before sample;
use heparinized syringe; apply pressure
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Diagnostic Studies of Respiratory
System (2 of 10)

CO2 monitoring (capnography)



Transcutaneous—electrode on skin
End-tidal—sensor analyzes exhaled air
Mixed venous blood gases (SvO2)
Sample from pulmonary artery using PA catheter or
fiberoptic sensor on central line
 Normal SvO2 = 60% to 80%

• Early warning of change in cardiac output or O2
delivery to tissues
• See Table 25-12
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38
Diagnostic Studies of Respiratory
System (3 of 10)

Sputum studies (See Table 25-13)

Expectoration, suctioning, or bronchoscopy for
sample; or induced
• Nursing: teach effective specimen production

Skin tests—intradermal injection


Allergies
TB (See Table 25-14)
• Nursing: read induration, not reddened area for
interpretation
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Diagnostic Studies of Respiratory
System (4 of 10)


Bronchoscopy
Direct visualization of bronchi
through scope



Obtain specimens
Remove mucous or foreign
bodies
A
Nursing:


Fiberoptic
bronchoscope
Before: verify consent; NPO;
sedated
After: NPO until gag returns;
monitor for hemorrhage or
pneumothorax
Smaller
bronchus
B
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Diagnostic Studies of Respiratory
System (5 of 10)


Bronchoscopy
Bronchoalveolar lavage (BAL)
 Sterile
saline injected through scope and
withdrawn to examine cells
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Diagnostic Studies of Respiratory
System (6 of 10)

Lung biopsy (Table 25-15)—verify consent
Transbronchial
Percutaneous/transthoracic needle aspiration (TTNA)
 Video-assisted thoracic surgery (VATS)
 Open lung biopsy
 Nursing—may include:


• Monitor for distress, pneumothorax, or bleeding; obtain
chest X-ray; incision or chest tube care; monitor breath
sounds; encourage deep breathing
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Diagnostic Studies of Respiratory
System (7 of 10)

Thoracentesis


Needle inserted through
chest wall to obtain
specimens, remove pleural
fluid, or instill medication
Nursing
Before—verify consent,
explain procedure
 During—position and
monitor
 After—monitor breath
sounds and for hypoxia and
pneumothorax; chest tube

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Diagnostic Studies of Respiratory
System (8 of 10)

Pulmonary function tests (PFTs)
Measures lung volumes and airflow
Diagnose and monitor disease progression; evaluate
treatment; determine disability
 Spirometer and computer calculate values; coaching
from trained personnel


• At home—peak flow meter

See Tables 25-16 and 25-17 in the textbook
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Diagnostic Studies of Respiratory
System (9 of 10)

Radiology—no metal; check pregnancy


Chest x-ray—most common
Computed tomography (CT)
• Nursing: check allergy to contrast/iodine; renal function;
encourage hydration before and after; feel warm and
flushed with injection

Magnetic resonance imaging (MRI)
• Nursing: screen for/remove all metal; check implantable
devices; address claustrophobia (sedation)

Ventilation-perfusion (V/Q) scan
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Diagnostic Studies of Respiratory
System (10 of 10)

Radiology

Pulmonary angiogram
• Nursing: contrast media precautions, pressure dressing
to injection site; monitor distal circulation

Positron emission tomography (PET)
• Nursing: NPO prior; monitor glucose levels; encourage
fluids
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46
Audience Response Question (1 of
2)
A patient’s arterial blood gas (ABG) results include
the following: pH 7.32, PaO2 84 mm Hg, PaCO2 49
mm Hg, and SaO2 84%. For what should the nurse
assess the patient?
a. Tetany
b. Tachypnea
c. Pleural friction rub
d. Kussmaul respirations
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47
Audience Response Question (2 of
2)
Answer: B
Tachypnea
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Audience Response Question (1 of
2)
The nurse would interpret an induration of 5 mm resulting
from tuberculin skin testing as a positive finding in which
patient?
a. A patient with a history of IV drug use
b. A patient who immigrated from India 3 months ago
c. A patient with diabetes and end-stage kidney disease
d. A patient with human immunodeficiency virus- infected
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49
Audience Response Question (2 of
2)
Answer: D
A patient who is human immunodeficiency virusinfected
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