Traumatic Pneumothorax - Types, Symptoms, Diagnosis, and Management

Introduction:

Pneumothorax is the presence of air between the parietal and visceral cavities. It is also known as the collapsed lung. A pneumothorax affecting a single lung is not dangerous unless and until it is associated with some chronic underlying pulmonary such as asthma, chronic obstructive lung disease, or it is complicated by tension pneumothorax. Pneumothorax can occur due to trauma from a road traffic accident or a penetrating injury, such as a stab or gunshot injury. The injury causes air to leak and accumulate between the lungs and the pleural cavity. The resulting increased pressure outside the lungs causes the lung to collapse.

What Are the Types of Pneumothorax?

Pneumothorax can be of various types like

Traumatic Pneumothorax: Traumatic pneumothorax may occur due to trauma or injury to the chest wall. Some types of injuries that can lead to traumatic pneumothorax are:

• Road traffic accidents.
• Stab or bullet injuries in the chest.
• Blow to the chest during sports.
• Flail segment or broken ribs.

Non-Traumatic Pneumothorax: It is also a spontaneous pneumothorax, unrelated to trauma. It can be further divided into:

Primary Pneumothorax: Occurs in a person with no lung disease, such as:

• Pregnant lady.
• Smokers.
• People with Marfan's syndrome.
• People with a family history of pneumothorax.

Secondary Pneumothorax: Occurs in a person with a known history of lung disease, such as:

• Chronic obstructive lung disease (COPD) patients.
• Cystic fibrosis patients.
• Lung cancer patients.
• Asthma patients.
• Idiopathic pulmonary fibrosis patients.
• Severe acute respiratory distress.
• Acute or chronic lung infections such as tuberculosis and pneumonia.
• Collagen vascular disease.

Pneumothorax can be further classified as:

• Simple Pneumothorax: It is also known as a closed pneumothorax.
• Tension Pneumothorax: It is a severe form of pneumothorax. A rapid accumulation of air with rapid symptoms can be observed. It may be seen when:
  • A blow to the chest.
  • Stabbing or penetrating injury in the chest.
  • A spontaneous pneumothorax progresses into a tension pneumothorax.

And also can be classified as:

• Open Pneumothorax: When air moves in and out of an open wound in the chest, for example, a gunshot wound.
• Closed Pneumothorax: There is a bidirectional airflow in the pleural cavity.

What Are the Signs and Symptoms of Pneumothorax?

Patients with a traumatic pneumothorax will have the following:

• Pleuritic chest pain.
• Dyspnea or difficulty in breathing.
• Tachypnea or increased respiratory rate.
• Tachycardia or increased heart rate.
• Low blood pressure or hypotension.
• Cyanosis or bluish discoloration of the tongue, the tip of the nose, and ear lobules.
• Breath sounds: May be diminished or hyper-resonant.
• Crackles may be heard on palpation.
• Hammam Sign: It is a characteristic crunching sound synchronized with the heartbeat.
• Enlarged jugular vein.
• One-sided enlargement of the lung.

What Are the Risk Factors for Developing Pneumothorax?

The risk factors for traumatic pneumothorax are:

• Contact sports like soccer, football, and hockey.
• The patient is on mechanical ventilation.
• Patients undergoing a medical procedure that involves the chest or lungs.

The risk factors for non-traumatic pneumothorax are:

• History of smoking.
• Family history of pneumothorax.
• History of underlying secondary pulmonary diseases such as COPD or asthma.

How Is Pneumothorax Diagnosed?

Pneumothorax can be diagnosed with the help of the following:

• Chest X-Ray: A radiographic finding of more than 2.5 cm of air space is equivalent to 30 % pneumothorax.
• Ultrasonography: It has proven to be a better diagnostic tool for pneumothorax. There will be an absence of lung sliding, an absence of comet tails artifact, and the presence of a lung point. Ultrasonography has better sensitivity and specificity, and it is always better than a chest x-ray.
• Computed Tomography (CT) Scan: Occult pneumothoraces can be observed but are not clinically relevant.

What Is the Management of Pneumothorax?

An asymptomatic patient with a small primary spontaneous pneumothorax of less than 2 cm is usually discharged with a follow-up in 2 to 4 weeks. If the patient becomes symptomatic or the size increases by 2 cm, a needle decompression is required. After the needle decompression, if the patient improves and the residual depth is less than 2 cm, then no thoracostomy tube insertion is required, and the patient can be discharged.

In secondary spontaneous pneumothorax, if the size or depth is less than 1 cm, the patient is admitted, and high-flow oxygen is given and observed for the next 24 hours. If the size is between 1 to 2 cm, then a needle decompression is required. The residual depth is seen after needle decompression; if the depth is less than 1 cm, then oxygen inhalation will help reduce the feature. Still, a thoracostomy tube must be inserted if it is more than 2 cm.

First and foremost, a needle decompression should be done for hemodynamically unstable patients who are showing deteriorating signs and symptoms. It is performed with the help of a 14 to 16 gauge and 4.5 cm in length angiocatheter, just superior to the rib of the second intercostal space in the midclavicular line, followed by insertion of the thoracostomy tube, which is inserted at the 5th intercostal space anterior to the mid axillary line.

The thoracostomy tube depends upon the patient's height and weight and whether there is an association with hemothorax. An open pneumothorax should be managed with the help of a three-sided occlusive dressing followed by a thoracostomy tube insertion to drain the accumulated fluid or air.

Patients who undergo video-assisted Thoracic surgery get pleurodesis to occlude the pleural space to inhibit air accumulation in the pleural cavity. Mechanical pleurodesis with bullectomy helps decrease the recurrence rate of pneumothorax.

What Are the Differential Diagnosis of Pneumothorax?

The differential diagnosis includes:

• Myocardial infarction.

• Pulmonary embolism.

• Acute pericarditis

• Esophageal spasm.

• Esophageal rupture.

• Rib fracture.

• Diaphragmatic injuries.

• Acute aortic dissection.

What Are the Complications of Pneumothorax?

Complications of pneumothorax include:

• Respiratory failure.

• Pulmonary edema.

• Pneumohemothorax.

• Pneumopericardium.

• Pneumoperitoneum.

• Bronchopulmonary fistula.

• Cardiac arrest.

Tension pneumothorax is very severe and can rapidly progress to inability to breathe, cardiovascular collapse, and ultimately death.

Conclusion:

The management of pneumothorax is done by the emergency department physician or the intensive care unit staff. A needle decompression method is necessary for a hemodynamically unstable patient. An untreated pneumothorax is an absolute contraindication for scuba diving or flying. And if there is a persistent, recurrent pneumothorax treated before with a thoracostomy tube, then video-assisted thoracic surgery with or without pleurodesis is necessary.