Subcutaneous Emphysema

Subcutaneous Emphysema Definition

Subcutaneous Emphysema (SCE or SE) is a condition that occurs if air or gas is trapped in the subcutaneous layer of the skin. The term “Subcutaneous” denotes the tissue located underneath the cutis of skin while “Emphysema” denotes trapped air.

Image Source : Wikimedia Commons

SE is also referred to by the following names:

• Tissue Emphysema
• Sub Q Air
• Crepitus
• Subcutaneous Air

Subcutaneous Emphysema Causes

The main causes for this condition include seepage of small amounts of air through lesions on the skin caused by some blunt trauma, stabbing or bullet wound. The air is immediately drawn in because of the muscular movements and Spreads quickly into the chest and neck cavity. Tissue Emphysema can occur post a Laparoscopic surgery. Other factors such as ruptured esophagus, bronchial tube and a malformed lung may also lead to SE. The therapeutic causes of the disorder are discussed below:

Pneumothorax

This condition occurs when the chest’s pleural cavity, located between the lungs and the chest wall, is filled with air or gas. The air build up applies pressure on the lung which can result in partial or complete lung collapse. A serious chest injury can lead to this condition.

Bronchial Tube Rupture

The trachea rupture can cause shortness of breath and subcutaneous crepitation. Bronchial Rupture is one of the main reasons for Subcutaneous Emphysema along with Hypotension, Tachycardia and Hemoptysis.

Esophageal Rupture

The application of certain medical instruments for diagnostic purposes can lead to perforation of the esophagus. Postoperative trauma and some esophagus disease can also cause this disorder which can result in Tissue Emphysema.

Infection

Necrotizing infections like gangrene (a late symptom of Gas Gangrene) can cause air to be trapped below the subcutaneous layer.

Dental Procedures

Subcutaneous Emphysema can occur due to certain dental procedures that uses compressed air equipments. Root canal is considered to be one of its possible causes.

Forceful vomiting due to Boerhaave’s syndrome can also cause this condition.

Subcutaneous Emphysema Pathophysiology

The air can travel from the mediastinum and retroperitoneum (the small space behind abdominal cavity) into the soft tissues located in the neck because all these areas are linked by fascial planes. The punctured airways and lungs allow the air to move up through the perivascular sheaths and enter the mediastinum. Once in the mediastinum, the air can easily travel into the subcutaneous tissues.

An alveoli rupture caused by increased pressure on the lung can result in spontaneous SE. In case of a spontaneous Tissue Emphysema, the air journeys from the perforated alveoli into interstitium. It then enters the mediastinum after traveling along blood vessels of the lungs. Finally, the air reaches the tissues of the head and neck.

Subcutaneous Emphysema Signs and Symptoms

The most common symptoms of this condition include:

• Inflammation around neck
• Chest pain
• Sore throat
• Trouble in swallowing
• Aching neck
• Wheezing
• Breathlessness

SC mainly occurs on the neck, chest and face as the air easily travels to these areas from chest cavity through the fascia. But they may also be found on the knee, thigh, hand, leg and foot. When touched, Subcutaneous Emphysema gives rise to a characteristic crackling sensation that is described to resemble the feeling of touching Rice Krispies. This feeling of air trapped under the skin is called subcutaneous crepitation.

The following symptoms can occur in severe cases of SE:

• Swelling of the entire face
• Swelling of the neck
• Change in the voice of an individual

In extremely serious conditions, the air can spread in various body parts like the abdomen and the limbs as the adipose tissue layer beneath the skin does not have any separations that can restrict the further movement of the air.

Subcutaneous Emphysema Prevention

There are no known ways of preventing Tissue Emphysema. Scientists are trying to find out some preventive methods that can decrease the chances of developing SE. Following a nutritious diet consisting of antioxidants in high amounts helps to improve the functioning of the lungs. This may help an individual to avoid the condition.

Subcutaneous Emphysema Diagnosis

Diagnosing prominent cases of Tissue Emphysema is quite simple due to its characteristic symptoms. In some instances, however, the signs are very subtle which makes it difficult to diagnose the disorder. Medical imaging procedures are used for diagnosing the presence of SE or for confirming a diagnosis done by using various clinical signs.

Subcutaneous Emphysema is visible on a chest radiograph as radiolucent striations arranged in the pattern of greater pectoral muscle group. Air present in subcutaneous tissues may make it difficult to detect serious conditions like Pneumothorax during the chest radiography. The effectiveness of a chest ultrasound can also be diminished due to this air. However, the fact that Tissue Emphysema is usually detected in a chest X-ray before a Pneumothorax becomes evident can be used to deduce the presence of the latter condition.

CT scans are also used for diagnosing Subcutaneous Emphysema. The air pockets caused by SE appear as dark spots on a CT scan. This diagnostic procedure is very sensitive and helps to locate the exact point from which the air is travelling into the soft tissues.

Subcutaneous Emphysema Differential Diagnosis

During the differential diagnosis of this condition, the following disorders which give rise to similar symptoms should be considered:

• Tracheobronchial Laceration
• Hypopharyngeal Perforation
• Barotrauma due to mechanical ventilation
• Esophageal Perforation

The absence of the above conditions can help doctors ensure that the problems experienced by sufferers are the result of SE.

Subcutaneous Emphysema Treatment and Management

Generally, Tissue Emphysema occurs as a benign condition. In most cases, SE does not require any treatment although the diseases causing the condition should be treated properly. However, if large amount of air is present in the Subcutaneous Emphysema, it may cause breathing problems, asthma and discomfort. In some rare cases, the condition advances to “Massive Subcutaneous Emphysema”, a very uncomfortable form of SE which needs surgical drainage. When massive amount of air is eliminated from the lungs, generally because of positive pressure ventilation, it causes the swollen eyelids of the patient to obstruct his or her eye sight. The air pressure may also block the blood-flow to areolae of the skin and breast of the labia or scrotum. This can cause necrosis in these skin areas. It is important to perform adequate decompression immediately if the air is causing necrosis in the body of a sufferer. In severe cases, the trachea can be compressed for the required treatment.

If the Subcutaneous Emphysema turns severe, a doctor can place catheters in the subcutaneous layer for releasing the air. “Blow holes” or small cuts can be made in the affected skin for eliminating the air.

The main aim of this treatment is to deal with the underlying disorder that is causing the SE. Due to this reason, a spontaneous Tissue Subcutaneous may need no treatment other than long bed rest, proper medication to relief the pain and supplemental oxygen (in certain serious cases). Breathing oxygen can help the body in absorbing the subcutaneous air quickly. It is also important to keep a patient under observation to see if the condition is worsening.

Subcutaneous Emphysema Chest Tube

If the condition is being caused by Pneumothorax, its treatment involves using a chest tube for understanding the situation. Placing a chest tube eliminates the source through which the air was entering the subcutaneous layer in the skin. Sometimes, the air leaking into the body is increased after the placement of the chest tube. Replacing the existing tube with a larger one helps to manage this situation.

Subcutaneous Emphysema Healing Time

The time required for the Tissue Emphysema to heal completely depends on its duration, severity and underlying causes. In some instances, the SE goes away by itself after some time while in others it requires treatment. Hence, the duration of the condition may vary greatly from one person to another.

Subcutaneous Emphysema Complications

A rare complication of using chest tube for treating SE is Tracheobronchial Laceration. This potentially serious condition can occur due to difficult and uneventful intubations. In most cases, the lacerations occur longitudinally in the posterior membranous wall of the trachea or in the place where the cartilaginous ring joins the membranous wall.

SE can also cause the following complications if left untreated:

• Compromising of airways
• Respiratory tract failure
• Internal tension in body

Subcutaneous Emphysema Prognosis

SE is not a lethal condition and does not pose any serious threat to a patient. Generally, the prognosis is positive with treatment. The body absorbs small amounts of this air. The SE generally clears up once the Pneumomediastinum or Pneumothorax causing the problem is treated properly. However, a spontaneous Tissue Emphysema can progress into a life-threatening condition in some rare instances.

SE caused by mechanical ventilation can induce ventilatory failure.

Subcutaneous Emphysema in Animals

Tissue Emphysema can occur in cats, dogs, horses and various cattle species. The main causes of SE in these animals are trauma, rib fracture and interstitial emphysema. However, early treatment can cure the condition completely.

Subcutaneous Emphysema Pictures

Here are some images displaying the appearance of patients with SE.

Picture 1 – Subcutaneous Emphysema

Picture 2 – Subcutaneous Emphysema Image

It is important to identify the SE before it progresses to an advanced stage to attain full recovery.