In atelectasis, alveolar clusters (lobules) or lung segments that expand incompletely may produce a partial or complete lung collapse. This phenomenon effectively removes certain regions of the lung from gas exchange. This allows unoxygenated blood to pass unchanged through these regions and produces hypoxia.
Atelectasis may be chronic or acute. The disorder occurs to some degree in many patients undergoing upper abdominal or thoracic surgery. The prognosis depends on prompt removal of any airway obstruction, relief of hypoxia, and reexpansion of the collapsed lung.
Signs and Symptoms
In acute atelectasis in which there is sudden obstruction of the bronchus, there may be dyspnea and cyanosis, elevation of temperature, a drop in blood pressure, or shock.
In the chronic form, the patient may experience no symptoms other than gradually developing dyspnea and weakness.
Other characteristics include diminished breath sounds, fever, and increasing dyspnea (shortness of breath).
Chest X-rays are the primary diagnostic tool, although extensive areas of "microatelectasis" can exist without abnormalities appearing on the films. In widespread atelectasis, X-ray findings define characteristic horizontal lines in the lower lung zones. With segmental or lobar collapse, the films reveal characteristic dense shadows (commonly associated with hyperinflation of neighboring lung zones).
Bronchoscopy may be used to rule out an obstructing neoplasm or a foreign body if the cause of atelectasis can't be determined.
Arterial blood gas analysis may reveal respiratory acidosis and hypoxemia resulting from atelectasis.
Incentive spirometry, chest percussion, postural drainage, and frequent coughing and deep-breathing exercises may improve oxygenation in the patient with atelectasis. If these measures fail, bronchoscopy may help remove secretions. Humidity and bronchodilator medications can improve mucociliary clearance and dilate airways. These drugs may be administered by nebulizer or by a face mask device that establishes continuous positive airway pressure. Alternatively, intermittent positive-pressure breathing therapy may be prescribed.
If the patient has atelectasis secondary to an obstructing neoplasm, he may need surgery or radiation therapy. To minimize the risk for atelectasis after thoracic and abdominal surgery, the patient requires analgesics to facilitate deep breathing.
Deep breathing, aided by the use of inspiration breathing apparatus following surgery, is helpful in preventing complications of atelectasis.
(c)Copyright Medical-clinic.org All rights reserved.
Disclaimer : All information on Medical-clinic.org is for educational and information purposes only. For specific medical advice, diagnoses, and treatment, please consult your doctor. We will not be liable for any complications, or other medical accidents arising from the use of any information on this web site.