Air space lung disease is an unofficial term that refers to air caught in the space between the outside of the lung and the inside of the chest cavity, between the pleural layers that are normally air tight. Called a pneumothorax, or sometimes collapsed lung, it can have any number of causes from injury to spontaneous development.
When air leaks inside the body outside of the lung the delicate pressure balance that holds the lung open is disrupted and all or part of the lung collapses and breathing becomes difficult. In severe cases the collapsed lung can put pressure on the heart, pushing it out of place and making it hard or impossible for the heart to beat normally. This is the most serious and life-threatening kind of pneumothorax called a tension pneumothorax.
Chest trauma or puncture injuries (motor vehicle accidents, violent crime) are the most common causes for pneumothorax. A spontaneous pneumothorax is one that happens when a weakened area of the lung wall ruptures suddenly, without any direct trauma or injury. This can happen when a small weakened area of the lung gives way and breaks open, when a disease-related cyst bursts (most common in emphysema patients), or when the body is exposed to pressure extremes in sports like scuba and sky diving. Men who are tall, thin and age 20-40 are at the highest risk for spontaneous pneumothorax.
The symptoms of a mild pneumothorax usually include shortness of breath, chest pain, chest tightness, rapid breathing, little to no chest movement with breaths and a dry cough. A tension pneumothorax will have the same symptoms (severely) along with anxiety, a weak pulse, bulging neck veins, and potentially a windpipe or trachea that is obviously pushed over to one side.
The diagnosis of a pneumothorax is made primarily by examination of the patient, including symptoms and listening with a stethoscope for diminished lung sounds on the affected side. A chest X-ray can confirm the diagnosis as it's the most accurate and will show where and how big the pneumothorax is. If a tension pneumothorax is suspected an ECG (electrocardiogram) can be used to check the heart's rhythm and beating strength, along with blood tests to measure how effectively the heart is pumping oxygen around the body.
If the pneumothorax is small enough it might resolve on its own, under close observation, as the air is absorbed into the blood stream and the body heals the ruptured area. In other cases a small needle and syringe can be inserted through the chest wall to remove the air, or a chest tube with a one-way valve might be inserted and left in place for a few days to allow continued suction as the lung heals. In life-threatening cases of tension pneumothorax surgery, chest tube placement, and monitoring of the heart and blood gas levels might be indicated, along with the possibility of additional surgery to seal the pleural layers and help prevent further recurrences.