Chapter 44
Postoperative Atelectasis
B
A
B
A
Figure 44-1. Alveoli in postoperative atelectasis. A, Total alveolar collapse.
B, Partial alveolar collapse.
Slide 1
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Anatomic Alterations of the Lungs
Slide 2

Alveoli of primary lobules (micro-atelectasis
or subsegmental atelectasis)—very common

Lung segment—fairly common

Lung lobe—less common

Entire lung—rare
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Etiology
Decreased Lung Expansion

Thoracic and upper abdominal procedures

Slide 3
Considered high risk for atelectasis
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Etiology
Decreased Lung Expansion
 Other precipitating factors

Anesthesia
 Postoperative pain
 Supine position
 Obesity
 Advanced age
 Inadequate tidal volumes during mechanical ventilation
 Malnutrition
 Ascites
 Diaphragmatic apraxia
 The presence of a restrictive lung disorders
Slide 4
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Etiology
Alveolar Degassing
Atelectasis associated with airway secretions and mucus plugs

Slide 5
Precipitating factors

Decreased mucociliary transport

Excessive secretions

Inadequate hydration

Weak or absent cough

General anesthesia

Smoking history

Gastric aspiration

Certain preexisting conditions (e.g., chronic bronchitis, asthma)
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Overview of the Cardiopulmonary
Clinical Manifestations Associated
with POSTOPERATIVE
ATELECTASIS
The following clinical manifestations result from
the pathophysiologic mechanisms caused (or
activated) by Atelectasis (see Figure 9-7)—the
major anatomic alterations of the lungs
associated with postoperative atelectasis (see
Figure 44-1)
Slide 6
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Figure 9-7. Atelectasis clinical scenario.
Slide 7
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Clinical Data Obtained at the
Patient’s Bedside
Vital signs
Slide 8

Increased respiratory rate

Increased heart rate, cardiac output,
blood pressure
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Clinical Data Obtained at the
Patient’s Bedside
Slide 9

Cyanosis

Cough, sputum production, and hemoptysis

Chest assessment findings

Increased tactile and vocal fremitus

Dull percussion note

Bronchial breath sounds

Diminished breath sounds
(when mucus plugs present)

Crackles

Whispered pectoriloquy
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Figure 2-11. A short, dull, or flat percussion note is typically produced over areas
of alveolar consolidation.
Slide 10
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Figure 2-16. Auscultation of bronchial breath sounds over a consolidated lung unit.
Slide 11
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Figure 2-19. Whispered voice sounds auscultated over a normal lung
are usually faint and unintelligible.
Slide 12
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Clinical Data Obtained from
Laboratory Tests and Special
Procedures
Slide 13
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Pulmonary Function Study:
Expiratory Maneuver Findings
FVC

FEVT
N or 
FEF25%-75%
N or 
FEF200-1200
N
PEFR
MVV
FEF50%
FEV1%
N
Slide 14
N or 
N
N or 
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Pulmonary Function Study:
Lung Volume and Capacity Findings
VT
Slide 15
RV
FRC
TLC
N or 



VC

IC

ERV

RV/TLC%
N
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Arterial Blood Gases
Small or Localized Postoperative Atelectasis

Acute alveolar hyperventilation with
hypoxemia
pH

Slide 16
PaCO2

HCO3 (Slightly)
PaO2

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Time and Progression of Disease
Disease Onset
Alveolar Hyperventilation
100
90
PaO2 or PaCO2
80
Point at which PaO2
declines enough to
stimulate peripheral
oxygen receptors
70
60
PaO2
50
40
30
20
10
0
Figure 4-2. PaO2 and PaCO2 trends during acute alveolar hyperventilation.
Slide 17
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Arterial Blood Gases
Widespread Postoperative Atelectasis

Acute ventilatory failure with hypoxemia
pH

Slide 18
PaCO2

HCO3 (Slightly)
PaO2

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Time and Progression of Disease
Disease Onset
Alveolar Hyperventilation
Acute Ventilatory Failure
100
90
80
70
Point at which PaO2
declines enough to
stimulate peripheral
oxygen receptors
Point at which disease
becomes severe and patient
begins to become fatigued
60
50
40
30
20
10
0
Figure 4-7. PaO2 and PaCO2 trends during acute ventilatory failure.
Slide 19
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Oxygenation Indices
QS/QT
DO2
VO2


Normal
O2ER

Slide 20
C(a-v)O2
Normal
SvO2

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Radiologic Findings
Chest radiograph
Slide 21

Increased density in areas of atelectasis

Air bronchograms

Elevation of the hemidiaphragm on the
affected side

Mediastinal shift toward the affected side
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General Management of
Postoperative Atelectasis

Precipitating factors for postoperative atelectasis
should be identified

High-risk patients should be monitored closely

Preventive measures should be prescribed for
high-risk patients

Slide 22

Incentive spirometry

Chest physical therapy
Whenever possible, treatment of the underlying
cause of atelectasis should be prescribed
immediately
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General Management of
Postoperative Atelectasis
Respiratory care treatment protocols
Slide 23

Oxygen therapy protocol

Bronchopulmonary hygiene therapy protocol

Hyperinflation therapy protocol

Mechanical ventilation protocol
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