Dependent atelectasis is a condition where all or part of a lung or lobe of a lung collapses. The condition is caused when the alveoli (tiny air sacs) inside the lung become deflated.
Atelectasis is a common complication following respiratory surgery. The condition can also occur as a complication of conditions such as lung tumors, cystic fibrosis, and respiratory weakness in older people.
Other causes of atelectasis include:
These causes of atelectasis are referred to as ‘obstructive’ atelectasis.
Atelectasis can also be caused by chest trauma and scarring of the lung tissue by disease or surgery. Some forms of pneumonia can cause temporary atelectasis, as can a leakage of air into the lungs and chest wall (pneumothorax). An accumulation of fluid between the lining of the lungs and inside of the chest wall (pleural effusion) can cause atelectasis.
The most common signs of atelectasis include:
If you experience any of these symptoms, especially following an accident in which you suffered chest trauma or after surgery, you should seek medical advice, especially if you have recently had surgery or fall into one of the aforementioned risk groups.
In order to make a definitive diagnosis of atelectasis, a number of tests will be carried out.
Chest X-rays are the first diagnostic tool that will be used. X-rays will clearly show any foreign bodies that may have entered the lungs and also highlight the areas of atelectasis that are present within the lungs.
CT scans are also used as part of the diagnostic process, as they are more accurate in helping doctors to measure lung volumes and are also more efficient in showing up tumors that may be sited deep within the lung tissue.
Oximetry will also be carried out via a small device that is placed on one of the fingers and is used to measure the oxygen saturation in the blood. Poor oxygen saturation may indicate that the lungs are compromised.
If your doctor thinks that you may have a mucus plug obstructing your airway, he may carry out a bronchoscopy. This entails having a flexible, illuminated tube inserted into your throat to confirm the diagnosis and remove the obstruction.
The treatment approach taken will depend on the underlying cause of the atelectasis. Small areas of atelectasis may often subside without the need for treatment.
Sometimes physiotherapy can help to re-expand the lung tissue and is usually carried out after surgery. Techniques employed include coughing, clapping percussion on the chest over the collapsed area to loosen accumulated mucus, use of an air-pulse vibrator vest or hand-held instrument.
Deep breathing exercises are often used and device-assisted deep coughing is also very effective. You may be encouraged to position your body with your head below your chest to encourage better drainage of mucus from the bottom of the lungs. This technique is called ‘postural drainage’.
In patients who are too weak to carry out deep coughing exercises and have low post-surgery oxygen levels continuous positive pressure on the chest may be used.
Throughout your recuperative treatments, supplemental oxygen may be used to help relieve any shortness of breath that you may be suffering.
If an airway obstruction is identified as the cause of the atelectasis, a bronchoscopy may be carried out in order to suck out mucus plugs or other foreign objects.
Dependent atelectasis is the term used to describe a collapsed area of the lung or a lobe of the lung. Atelectasis is a common post-surgery complication that surgical teams will be aware of.
However, there are other causes, and if you are concerned that you may have atelectasis, always seek the advice of a medical professional.