ATELECTASIS
INNOCENT OKOLO
1007
• Atelectasis is defined as the collapse or closure of
the lung resulting in reduced or absent gas
exchange. It may affect part or all of one lung. If
only a small area or a few small areas of lung are
affected, you may have no signs or symptoms. It is a
condition where the alveoli are deflated, as distinct
from pulmonary consolidation
• It is a very common finding in chest x-rays and other
radiological studies. It may be caused by normal
exhalation or by several medical conditions.
Although frequently described as a collapse of lung
tissue, atelectasis is not synonymous with a
pneumothorax, which is a more specific condition
that features atelectasis. Acute atelectasis may
occur as a post-operative complication or as a result
of surfactant deficiency. In premature neonates, this
leads to infant respiratory distress syndrome.
CLASSIFICATION
• Atelectasis may be an acute or chronic condition.
In acute atelectasis, the lung has recently collapsed
and is primarily notable only for airlessness. In
chronic atelectasis, the affected area is often
characterized by a complex mixture of airlessness,
infection, widening of the bronchi (bronchiectasis),
destruction, and scarring (fibrosis).
CHRONIC ATELECTASIS
• . In right middle lobe syndrome, the middle lobe of
the right lung contracts, usually because of pressure
on the bronchus from enlarged lymph glands and
occasionally a tumor. The blocked, contracted lung
may develop pneumonia that fails to resolve
completely and leads to chronic inflammation,
scarring, and bronchiectasis.
• In rounded atelectasis (folded lung syndrome), an
outer portion of the lung slowly collapses as a result
of scarring and shrinkage of the membrane layers
covering the lungs (pleura). This produces a
rounded appearance on x-ray that doctors may
mistake for a tumor. Rounded atelectasis is usually a
complication of asbestos-induced disease of the
pleura, but it may also result from other types of
chronic scarring and thickening of the pleura.
ABSORPTION ATELECTASIS
• The atmosphere is composed of 78% nitrogen and
21% oxygen. Since oxygen is exchanged at the
alveoli-capillary membrane, nitrogen is a major
component for the alveoli's state of inflation. If a
large volume of nitrogen in the lungs is replaced
with oxygen, the oxygen may subsequently be
absorbed into the blood, reducing the volume of
the alveoli, resulting in a form of alveolar collapse
known as absorption atelectasis.
SYMPTOMS
• May have no signs and symptoms or they may
include:
• Cough, but not prominent;
• chest pain, (not common);
• breathing difficulty, (fast and shallow);
• low oxygen saturation;
• pleural effusion (transudate type);
• Cyanosis (late sign);
• increased heart rate.
NO FEVER!!!!
• It is a common misconception that atelectasis
causes fever. A study of 100 post-op patients
followed with serial chest X-rays and temperature
measurements showed that the incidence of fever
decreased as the incidence of atelectasis
increased. A recent review article summarizing the
available published evidence on the association
between atelectasis and post-op fever concluded
that there is no clinical evidence supporting this
dogma.[
CAUSES
• The most common cause is post-surgical atelectasis,
characterized by splinting, i.e. restricted breathing
after abdominal surgery. Smokers and the elderly
are at an increased risk. Outside of this context,
atelectasis implies some blockage of a
bronchiole\or bronchus, which can be within the
airway (foreign body, mucus plug), from the wall
(tumor, usually squamous cell carcinoma) or
compressing from the outside (tumor, lymph node,
tubercle).
• Another cause is poor surfactant spreading during
inspiration causing the surface tension to be at its
highest which tends to collapse smaller alveoli.
Atelectasis may also occur during suction, as along
with sputum, air is withdrawn from the lungs. There
are several types of atelectasis according to their
underlying mechanisms or the distribution of
alveolar collapse; resorption, compression,
microatelectasis and contraction atelectasis
DIAGNOSIS
• chest X-ray
• computed tomography
• bronchoscopy
TREATMENT
• Treatment is directed at correcting the underlying cause. Postsurgical atelectasis is treated by physiotherapy, focusing on
deep breathing and encouraging coughing. An incentive
spirometer is often used as part of the breathing exercises.
Ambulation is also highly encouraged to improve lung
inflation. People with chest deformities or neurologic
conditions that cause shallow breathing for long periods may
benefit from mechanical devices that assist their breathing.
One method is continuous positive airway pressure, which
delivers pressurized air or oxygen through a nose or face mask
to help ensure that the alveoli do not collapse, even at the
end of a breath. This is helpful, as partially inflated alveoli can
be expanded more easily than collapsed alveoli. Sometimes
additional respiratory support is needed with a mechanical
ventilator
• The primary treatment for acute massive atelectasis
is correction of the underlying cause. A blockage
that cannot be removed by coughing or by
suctioning the airways often can be removed by
bronchoscopy. Antibiotics are given for an
infection. Chronic atelectasis is often treated with
antibiotics because infection is almost inevitable. In
certain cases, the affected part of the lung may be
surgically removed when recurring or chronic
infections become disabling or bleeding is
significant. If a tumor is blocking the airway,
relieving the obstruction by surgery, radiation
therapy, chemotherapy, or laser therapy may
prevent atelectasis from progressing and recurrent
obstructive pneumonia from developing.
CASE STUDY
• A 57 yr man is admitted to the hospital with CC: SOB for
3-4 days. He is confused and c/o cough productive of
yellow sputum. He remembers falling 4 times over the last
3 weeks without loosing consciousness. In the ER the
patient was very tachypneic and hypoxic, and was
intubated.
Chest x-ray showed a right lung opacification.
What is the most likely reason for the lung opacification?
Pneumonia?
Effusion?
Atelectasis?
WHAT DID WE LEARN FROM THIS
CASE?
• The sequence of events was: falls, multiple rib
fractures, hypoventilation, atelectasis, pneumonia
and respiratory failure
REFERENCES
• Wedding, Mary Ellen; Gylys, Barbara A. (2005). Medical
Terminology Systems: A Body Systems Approach: A Body
Systems Approach.
• White, Gary C. (2002). Basic Clinical Lab Competencies
for Respiratory Care, 4th ed. Delmar Cengage Learning.
p. 230
• http://www.mayoclinic.org/diseasesconditions/atelectasis/basics/symptoms/con-20034847
Engoren M (January 1995).
• "Lack of association between atelectasis and fever".
Chest 107 . Mavros MN, Velmahos GC, Falagas ME
(2011). "Atelectasis as a cause of postoperative fever:
where is the clinical evidence?". Chest 140 (2)