Pneumothorax

                     Pneumothorax

Definition

Pneumothorax is generally a collapsed lung. Normally, the pressure in the lungs is greater than the pressure in the pleural space surrounding the lungs. If air enters the pleural space, the pressure in the pleura then becomes greater than the pressure in the lungs, causing the lung to collapse partially or completely. Pneumothorax can be caused spontaneously or because of unfortunate trauma. If the cause of pneumothorax is unknown, it is called spontaneous pneumothorax. Such condition often strikes the thin, tall men between 20 – 40 ages.

Pneumothorax may also be described as either a simple pneumothorax, without effects on the heart or mediastinal structures, or as a tension pneumothorax, which is a life-threatening condition. Tension pneumothorax can occur as a result of trauma, lung infection, or medical procedures, such as high-pressure mechanical ventilation, chest compression during cardiopulmonary resuscitation (CPR), or thoracoscopy (closed-lung biopsy).

Pathophysiology

• Intrapleural pressure is normally negative (less than atmospheric pressure) because of inward lung and outward chest wall recoil.
• In pneumothorax, air enters the pleural space from outside the chest or from the lung itself via mediastinal tissue planes or direct pleural perforation.
• Intrapleural pressure increases, and lung volume decreases.

Types of Pneumothorax and their causes

There are several major types of pneumothorax and various causes for each. Each kind may result in a partial or total collapse of one or both lungs depending on circumstances.

Tension pneumothorax

Tension pneumothorax refers to the condition in which air builds up under pressure and usually totally collapses one or both of the lungs. This causes severe dysfunction of the cardiovascular system. The pressure developed in the cavity of lung slows down or arrest the return of blood to the heart from the veins. Hence, the heart receives less blood to pump into the main arteries, blood pressure drops, and other vital organs are rapidly affected.

Simple pneumothorax

In this type of pneumothorax, there is a partial collapse of the lung. The pressure built up in the lung cavity is not sufficient to cause cardiovascular dysfunction. The partially collapsed lung may be lead to decreased amounts of oxygen in blood and shortness of breath. This type of pneumothorax can be small and stable and doesn’t require emergency treatment. However, it may gradually develop to cause severe cardiovascular dysfunction and may need to be monitored very often.

Spontaneous pneumothorax

This refers to a condition in which the lung collapses with no apparent injury or trauma. Abnormal, small, air-filled sacs in the lung called “blebs” typically rupture and leak air into the pleural space, leading to the spontaneous pneumothorax.

Traumatic pneumothorax

Direct trauma to the chest wall from either blunt or penetrating trauma causes this condition. Trauma also can come from diagnostic or therapeutic medical procedures that can result in a punctured lung such as needle aspiration of fluid from the pleural space, a lung biopsy, or insertion of a large IV catheter into a vein near the neck.

Disease-related pneumothorax

Disease-related pneumothorax can occur due to abnormalities in the lung tissue. A collapsed lung can arise as a complication of the following conditions:

• Asthma
• Cystic fibrosis
• Chronic obstructive pulmonary disease (COPD),
• Pneumocystis jirovecii pneumonia (PCP)

Risk factors

• Very tall, thin people are prone to a spontaneous pneumothorax
• Cigarette smoking
• Recreational drug use or abuse
• age <40 li="" years="">
• Chest trauma
• FHx of pneumothorax
• Tuberculosis

Symptoms

Common symptoms of a collapsed lung include:

• Sharp chest or shoulder pain, made worse by a deep breath or a cough
• Shortness of breath
• Nasal flaring (from shortness of breath)

A larger pneumothorax causes more severe symptoms, including:

• Bluish color of the skin due to lack of oxygen
• Chest tightness
• Lightheadedness and near fainting
• Easy fatigue
• Rapid heart rate
• Shock and collapse

Complications

Some of the complications which includes

• In future, there may be a chance for another collapsed lung
• Shock, if there are serious injuries or infection, severe inflammation, or fluid in the lung develop
• Air may sometimes continue to leak if the opening in the lung won’t close.

Diagnosis and test

The diagnosis can be based on the presence of airspace around the lungs. Detecting this can be difficult. Some imaging tests may be compromised by the air’s position between the chest wall and lung.

Imaging tests commonly used to diagnose pneumothorax include:

• An upright posteroanterior chest radiograph
• A CT scan
• Lung sonography
• A thoracic ultrasound

Treatment and medications

Maintain a closed chest drainage system: Be sure to tape all connections, and secure the tube carefully at the insertion site with adhesive bandages. Regulate suction according to the chest tube system directions; generally, suction does not exceed 20 to 25 cm H2O negative pressure.

Autotransfusion: Autotransfusion involves taking the patient’s own blood that has been drained from the chest, filtering it, and then transfusing it back into the vascular system.

Monitor a chest tube unit for any kinks or bubbling: These could indicate an air leak, but do not clamp a chest tube without a physician’s order because clamping may lead to tension pneumothorax.

Chest tube: A small chest tube is inserted near the second intercostal space to drain the fluid and air. For patients with the jeopardized gas exchange, chest tube insertion may be necessary to achieve lung re-expansion. The priority is to maintain airway, breathing, and circulation. The most important interventions focus on rein flatting the lung by evacuating the pleural air. Patients with a primary spontaneous pneumothorax that is small with minimal symptoms may have spontaneous sealing and lung re-expansion.

Antibiotics: Antibiotics are usually prescribed to combat infection from contamination.

Oxygen therapy: The patient with possible tension pneumothorax should immediately be given a high concentration of supplemental oxygen to treat the hypoxemia.

Prevention

There is no known way to prevent a collapsed lung. Following standard procedure can reduce the risk of a pneumothorax when scuba diving. You can decrease your risk by not smoking.