Atelectasis


Atelectasis

DiseaseDisorder infobox
Name = Atelectasis
ICD10 = ICD10|J|98|1|j|95
ICD9 = ICD9|518.0
ICDO =


Caption =
OMIM =
OMIM_mult =
MedlinePlus = 000065
eMedicineSubj = med
eMedicineTopic = 180
DiseasesDB = 10940
MeshID = D001261

Atelectasis is a collapse of lung tissue affecting part or all of one lung. [Medical Terminology Systems: A Body Systems Approach, 2005] It is a condition where the alveoli are deflated, as distinct from pulmonary consolidation. Infant respiratory distress syndrome includes another type of atelectasis, and is described and discussed in its own article.

Causes

The most common cause is post-surgical atelectasis, characterized by splinting, 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 an increase in surface tension 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 Atelectasis may also occur during suction, as along with sputum, air is withdrawn from the lungs.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.

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).

Acute Atelectasis

Acute atelectasis is a common postoperative complication, especially after chest or abdominal surgery. Acute atelectasis may also occur with an injury, usually to the chest (such as that caused by a car accident, a fall, or a stabbing). Atelectasis following surgery or injury, sometimes described as massive, involves most alveoli in one or more regions of the lungs. In these circumstances, the degree of collapse among alveoli tends to be quite consistent and complete. Large doses of opioids or sedatives, tight bandages, chest or abdominal pain, abdominal swelling (distention), and immobility of the body increase the risk of acute atelectasis following surgery or injury, or even spontaneously.

In acute atelectasis that occurs because of a deficiency in the amount or effectiveness of surfactant, many but not all alveoli collapse, and the degree of collapse is not uniform. Atelectasis in these circumstances may be limited to only a portion of one lung, or it may be present throughout both lungs. When premature babies are born with surfactant deficiency, they always develop acute atelectasis that progresses to neonatal respiratory distress syndrome. Adults can also develop acute atelectasis from excessive oxygen therapy and from mechanical ventilation.

Chronic Atelectasis

Chronic atelectasis may take one of two forms—middle lobe syndrome or rounded atelectasis. In 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.

Another cause of Atelectasis is a Pulmonary Embolism (PE).

ymptoms

* cough, but not prominent
* chest pain (rare)
* breathing difficulty
* low oxygen saturation
* fever -- debatable; no evidence to support this, although it is widely accepted
* pleural effusion (transudate type)
* cyanosis (late sign)
* increased heart rate

Diagnosis

* chest X-rayPost-surgical atelectasis will be bibasal in pattern.
* computed tomography
* bronchoscopy

Treatment

Treatment is directed at correcting the underlying cause. Post-surgical 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 often is 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.

Footnotes

Incentive Spirometer is also used to prevent or help treat atelectasis after surgery.

References

*cite|author=Gylys, Barbara A. and Mary Ellen Wedding|title=Medical Terminology Systems|publisher=F.A. Davis Company|date=2005 Paul H. Park

External links

*


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Look at other dictionaries:

  • atelectasis — incomplete expansion of the lungs, 1836, medical Latin, from Gk. ateles imperfect, incomplete, lit. without an end, (from a , privative prefix, + telos completion ) + ektosis extention. Related: Atelectatic …   Etymology dictionary

  • atelectasis — [at΄ə lek′tə sis] n. pl. atelectases [at΄ə lek′təsēz΄] [ModL < Gr atelēs, incomplete ( < a , without + telos, end: see WHEEL) + ektasis, a stretching out < ek , out + teinein, to stretch: see THIN] the collapse of all or part of a lung …   English World dictionary

  • atelectasis — atelectatic /at l ek tat ik/, adj. /at l ek teuh sis/, n. Pathol. 1. incomplete expansion of the lungs at birth, as from lack of breathing force. 2. collapse of the lungs, as from bronchial obstruction. [1855 60; < NL; see ATELIOSIS, ECTASIS] * * …   Universalium

  • atelectasis — Decreased or absent air in the entire or part of a lung, with resulting loss of lung volume. Loss of lung volume itself. SEE ALSO: pulmonary collapse. [G. ateles, incomplete, + ektasis, extension] adhesive a. alveolar …   Medical dictionary

  • atelectasis — n. failure of part of the lung to expand. This occurs when the cells lining the air sacs (alveoli) are too immature, as in premature babies, and unable to produce the wetting agent (surfactant) with which the surface tension between the alveolar… …   The new mediacal dictionary

  • atelectasis — noun (plural atelectases) Etymology: New Latin, from Greek atelēs incomplete, defective (from a 2a + telos end) + ektasis extension, from ekteinein to stretch out, from ex + teinein to stretch more at telos, thin Date …   New Collegiate Dictionary

  • atelectasis — noun The collapse of a part of or the whole lung caused by inner factors rather than a pneumothorax …   Wiktionary

  • atelectasis — n. collapse of the lungs (Medicine) …   English contemporary dictionary

  • atelectasis — [ˌatɪ lɛktəsɪs] noun Medicine partial collapse or incomplete inflation of the lung. Origin C19: from Gk atelēs imperfect + ektasis extension …   English new terms dictionary

  • atelectasis — at·el·ec·ta·sis …   English syllables


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