Atelectasis - definition, symptoms and treatment
What is Atelectasis and Definition
Atelectasis is the collapse of a segment or lobe of the lung, or an entire lung. Atelectasis is fairly common and most often spontaneously corrects itself for full recovery. The collapse may result from obstruction, structural damage to lung tissue, fibrosis that destroys bronchial segments, PNEUMOTHORAX, PLEURAL EFFUSION, and other causes. A form of chronic atelectasis, right middle lobe syndrome, results from chronic INFLAMMATION of the LYMPH nodes near the area, which are beneath the right lung’s middle lobe. A common cause of atelectasis is taking shallow breaths, which is common in people coming out of ANESTHESIA but still sedated after surgery or who have abdominal or chest wall pain.
Symptoms of Atelectasis and Diagnostic Path
Symptoms of atelectasis vary with the rate of onset and the extent of lung area involved. Rapid collapse may cause sharp PAIN and sudden DYSPNEA and may also cause severe COUGH. Chronic atelectasis or atelectasis that develops gradually may produce few symptoms, though many people develop a persistent, nonproductive cough.
The diagnostic path begins with careful AUSCULTATION for BREATH SOUNDS. Typically the collapsed segment causes displacement within the thoracic cavity of the affected lung, and often the unaffected lung as well as the HEART. Breath sounds may be normal though heard in abnormal locations. The doctor may also hear wheezes or rales, abnormal breath sounds that suggest blocked airways. Chest X-RAY clearly shows the displacement and the extent of the collapse. In the simplest case, coughing and deep breathing may resolve the atelectasis. In other cases, the doctor may desire additional diagnostic imaging such as COMPUTED TOMOGRAPHY (CT) SCAN to precisely identify the site of the atelectasis as well as the possible cause (such as a tumor or an obstruction). BRONCHOSCOPY may allow the pulmonologist to directly visualize the collapsed area and remove an obstruction such as a foreign object or mucus plug, if that is the cause of the collapse. Bronchoscopy also permits BRONCHOALVEOLAR LAVAGE or biopsy, if indicated.
Atelectasis Treatment Options and Outlook
Often, segmental atelectasis requires no treatment beyond watchful waiting or encouraging deep breathing. The lung will correct itself. Infection requires treatment with ANTIBIOTIC MEDICATIONS; inflammation may require treatment with CORTICOSTEROID MEDICATIONS. Other medications that sometimes relieve discomfort and help the lung restore itself include bronchodilators, which relax and open the airways. CHEST PERCUSSION AND POSTURAL DRAINAGE help keep the lungs free from accumulated secretions, and the doctor may recommend the person lie on his or her unaffected side to allow gravity to help restore the collapsed segment. Rarely, the doctor may consider surgery for chronic atelectasis that fails to respond to medical treatment. Most people recover from atelectasis without complications.
Risk Factors and Preventive Measures
Risk factors for atelectasis include obstructive pulmonary conditions such as CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD), CYSTIC FIBROSIS, chronic BRONCHITIS, and BRONCHIECTASIS. Recent surgery with general anesthesia is a common cause of atelectasis. Though avoiding these circumstances may not be possible, being alert to the possibility of atelectasis allows medical evaluation and intervention before complications such as infection or PNEUMONIA establish themselves.
See also CYSTIC FIBROSIS AND THE LUNGS; LUNG CANCER; SMOKING AND PULMONARY DISEASE; SURGERY BENEFIT AND RISK ASSESSMENT.
