What is pneumothorax?

A pneumothorax is a collapsed lung, a condition that occurs when air leaks into the cavity between the lungs and chest wall. This cavity is known as the pleural space.

A pneumothorax can range in its severity. Small pneumothoraces that are not associated with any complications can heal on their own, whereas more serious cases that involve large volumes of trapped air may become fatal if medical care is not sought.

 

Pleural space

The space in between the two thin linings that coat the lungs and internal chest cavity.

Causes

Air can enter the pleural space if there is a hole in the lung or the chest wall. The air accumulates inside the pleural space, pushes on the outside of the lung and causes it to collapse. A collapsed lung cannot expand as normal, and therefore breathing is restricted and the body cannot receive as much oxygen as it normally does.

Pleural space

The space in between the two thin linings that coat the lungs and internal chest cavity.

Risk factors

Some factors that can increase the risk of developing a pneumothorax include:

Marfan syndrome

A genetic disorder that affects the body's connective tissue. This condition can affect many different parts of the body, but commonly affects the heart, blood vessels, bones, joints and eyes.

Thoracic endometriosis

The migration of the lining of the uterus from a woman's pelvis to the chest cavity.

Types

There are different types of pneumothoraces, and each is classified according to its specific cause.

Primary spontaneous pneumothorax

This occurs when there is no known underlying lung condition, and without any inciting event. It:

  • Is most common in thin and tall adult men aged between 18-40 years;
  • Rarely occurs over the age of 40;
  • Typically occurs during rest, but may also occur during diving or high-altitude flying due to pressure changes in the lungs;
  • Is more common in smokers;
  • Is often caused by the rupture of an air-filled sac within the lung, called a bleb, and;
  • Has a recurrence rate of around 20%.

Secondary spontaneous pneumothorax

This occurs as a complication of an underlying lung condition, typically in people over 60 years of age. Secondary spontaneous pneumothorax:

  • Is most often caused by the rupture of a bleb or bulla, and;
  • Tends to be more serious than primary spontaneous pneumothorax, due to the more compromised health of the people in this group.

Traumatic pneumothorax

A traumatic pneumothorax is caused by a blunt or penetrating chest injury, such as from:

  • A stab wound;
  • A fractured rib, or;
  • An airbag impact in a motor vehicle accident.

Catamenial pneumothorax

A catamenial pneumothorax occurs in women only, within 72 hours from the onset of menstruation. It is caused by thoracic endometriosis. This generally occurs in women between 30-40 years of age, and more commonly occurs in the right lung.

Menstruation

The periodic shedding of the lining of a woman's uterus. Typically occurring about every four weeks between puberty and menopause (except during pregnancy). The menstrual period varies between individuals, but typically lasts 3-5 days.

Thoracic endometriosis

The migration of the lining of the uterus from a woman's pelvis to the chest cavity.

Bulla

Fluid-filled sacs or lesions that appear when fluid is trapped under a thin layer of your skin.

Bleb

1. Fluid-filled sacs, which can develop within different tissues. 2. Air-filled sacs within the lining of the lung, which can spontaneously rupture, causing a collapsed lung.

Signs and symptoms

The symptoms of pneumothorax may vary depending on the size and type of pneumothorax, and whether there is an underlying medical condition.

Some people may not experience any symptoms. If symptoms do occur, they may include:

  • Shortness of breath;
  • Chest pain;
  • A bluish discolouration of the skin, caused by a lack of oxygen (cyanosis);
  • Fatigue, and;
  • A rapid heart rate.

Fatigue

A state of exhaustion and weakness.

Methods for diagnosis

Diagnosis of a pneumothorax is typically based on a physical examination to assess lung function, and to see if there is any compression on one side of the chest.

A pneumothorax is usually diagnosed with a chest X-ray. Other tests that may be carried out to confirm a pneumothorax include:

  • Pulse oximetry - to measure blood oxygen levels;
  • An electrocardiogram (ECG) - to measure the electrical activity of the heart, and;
  • Computerised tomography (CT) scan or ultrasound - to obtain more detailed images of the lungs.

Computerised tomography

A scan that uses X-rays to create a 3D image of the body. This can detect abnormalities more effectively than a simple X-ray can.

Ultrasound

A scan that uses high-frequency soundwaves to produce images of the body’s internal structures.

Types of treatment

Treatment of a pneumothorax is aimed at removing air from the pleural space and preventing its recurrence. Treatment will vary depending on the symptoms, the size of the pneumothorax and its cause.

There are both surgical and non-surgical treatment options:

Non-surgical treatment

Non-surgical treatment can be used for most cases of uncomplicated primary spontaneous pneumothorax.

Observation

'Watchful waiting' may be sufficient for small and symptomatic primary spontaneous pneumothoraces.

Needle aspiration and chest tube insertion

Needle aspiration may be used to remove excess air from the pleural space. Needle aspiration involves inserting a tube between the ribs and using a syringe or suction device to extract the air. Larger pneumothoraces may require a chest tube that will stay in place for a few days.

Surgical treatment

Surgical treatment may be used for repeated episodes, or when the lung has not expanded after five days with a chest tube in place.

Video-assisted thoracoscopic surgery (VATS)

Video-assisted thoracoscopic surgery is effective both in treating a spontaneous pneumothorax and preventing it from recurring. Surgery may involve the removal of the bleb or bullae, and manipulation of the lung to make it stick to the chest wall. The rate of recurrence is reduced to less than 5% with VATS. [1] Alternatively, chemical pleurodesis can be used to prevent further pneumothorax.

Chemical pleurodesis

Chemical pleurodesis involves the insertion of a chemical irritant into the pleura through a chest tube to cause the pleura to stick together. It decreases the recurrence rate to around 20-25%.

Thoracotomy

Thoracotomy - making an open incision in the chest - has mostly been replaced by VATS (see above) in treating pneumothorax, as VATS involves a shorter hospitalisation and less pain. Thoracotomy is recommended in certain cases where VATS is not available, or if it has failed.

Pleura

The pleura is the two thin linings that coat the lungs and internal chest cavity.

Bullae

Fluid-filled sacs or lesions that appear when fluid is trapped under a thin layer of your skin.

Bleb

1. Fluid-filled sacs, which can develop within different tissues. 2. Air-filled sacs within the lining of the lung, which can spontaneously rupture, causing a collapsed lung.

Pleural space

The space in between the two thin linings that coat the lungs and internal chest cavity.

1. Hwong, Thomas M. T., Calvin S. H. Ng, Tak Wai Lee, Song Wan, Alan D. L. Sihoe, Innes Y. P. Wan, Ahmed A. Arifi, and Anthony P. C. Yim. “Video-Assisted Thoracic Surgery for Primary Spontaneous Hemopneumothorax.” European Journal of Cardio-Thoracic Surgery: Official Journal of the European Association for Cardio-Thoracic Surgery 26, no. 5 (November 2004): 893–96. doi:10.1016/j.ejcts.2004.05.014.

Potential complications

Tension pneumothorax

This serious complication can occur in any person with a pneumothorax, but is more common in people who are receiving positive-pressure ventilation, such as mechanical ventilation or during resuscitation. It occurs when air becomes trapped in the pleural space and creates enough pressure to put pressure on nearby organs and blood vessels. The pressure can limit the flow of blood back to the heart, which can quickly lead to loss of heart function and loss of breathing.

A tension pneumothorax is a life-threatening emergency, and is treated by performing an emergency needle decompression, which involves inserting a needle into the pleural space to relieve any pressure.

Air leaks

Air leaks are usually caused by the original problem that led to the development of the pneumothorax. They are more common in secondary spontaneous pneumothoraces and most cases will resolve on their own within a week.

Failure of lung expansion

The lung can fail to expand when there is a persistent air leak, the lung is trapped, or a chest tube has been poorly positioned. If the lung remains collapsed for more than a week, treatment may involve VATs.

Re-expansion pulmonary oedema

This rare complication can occur in certain situations when air is emptied quickly from the pleural space. The lung may fill up with fluid, causing difficulty breathing. Treatment of re-expansion pulmonary oedema involves supportive care with oxygen, diuretics and cardiopulmonary support as required.

Diuretics

A substance that promotes the production and excretion of urine.

Pleural space

The space in between the two thin linings that coat the lungs and internal chest cavity.

1. Hwong, Thomas M. T., Calvin S. H. Ng, Tak Wai Lee, Song Wan, Alan D. L. Sihoe, Innes Y. P. Wan, Ahmed A. Arifi, and Anthony P. C. Yim. “Video-Assisted Thoracic Surgery for Primary Spontaneous Hemopneumothorax.” European Journal of Cardio-Thoracic Surgery: Official Journal of the European Association for Cardio-Thoracic Surgery 26, no. 5 (November 2004): 893–96. doi:10.1016/j.ejcts.2004.05.014.

Prognosis

The outcome for pneumothorax depends on its size and type. Smaller pneumothoraces can heal on their own, whereas pneumothoraces associated with underlying conditions require treatment. While death from pneumothorax is rare, there is a high rate of recurrence.

1. Hwong, Thomas M. T., Calvin S. H. Ng, Tak Wai Lee, Song Wan, Alan D. L. Sihoe, Innes Y. P. Wan, Ahmed A. Arifi, and Anthony P. C. Yim. “Video-Assisted Thoracic Surgery for Primary Spontaneous Hemopneumothorax.” European Journal of Cardio-Thoracic Surgery: Official Journal of the European Association for Cardio-Thoracic Surgery 26, no. 5 (November 2004): 893–96. doi:10.1016/j.ejcts.2004.05.014.

Prevention

Quitting smoking can decrease the chance of pneumothorax.  

1. Hwong, Thomas M. T., Calvin S. H. Ng, Tak Wai Lee, Song Wan, Alan D. L. Sihoe, Innes Y. P. Wan, Ahmed A. Arifi, and Anthony P. C. Yim. “Video-Assisted Thoracic Surgery for Primary Spontaneous Hemopneumothorax.” European Journal of Cardio-Thoracic Surgery: Official Journal of the European Association for Cardio-Thoracic Surgery 26, no. 5 (November 2004): 893–96. doi:10.1016/j.ejcts.2004.05.014.