PNEUMOTHORAX

Prepared by:Sharmin Susiwala

Contents:

1. Definition2. Types3. Etiology4. Clinical features5. Pathophysiology6. Diagnosis7. Treatment 8. Complications

• Definition:“Pneumothorax is an abnormal collection of air or gas in

the pleural space separating the lung from the chest wall which may interfere with normal breathing, causing the lungs to collapse.”

• Types:1. Spontaneous pneumothorax:• Primary: A primary pneumothorax is one that occurs

without an apparent cause and in the absence of significant lung disease.

• Secondary: A secondary pneumothorax occurs in the presence of pre-existing lung pathology.

• Catamenial: Catamenial pneumothorax refers to the development of pneumothorax at the time of menstruation.

2. Traumatic pneumothorax:• Open: Chest wall is

damaged by any wound --outside air enters pleural space and causes lungs to collapse.

• Closed: here chest wall is punctured or air leaks from a ruptured bronchus (or a perforated esophagus)

• Iatrogenic : for e.g. Postoperative Mechanical ventilation Thoracocentesis Central venous cannulation

Open Pneumothorax

3. Tension pneumothorax:• Aka pressure pneumothorax.• The amount of air in the chest

increases markedly when a one-way valve is formed by an area of damaged tissue, leading to a tension pneumothorax.

• This condition is a medical emergency that can cause steadily worsening oxygen shortage and low blood pressure.

• Unless reversed by effective treatment, these sequelae can progress and cause death.

Tension Pneumothorax

• Causes/ Risk factors:• Primary spontaneous pneumothorax: (PSP) The exact cause of primary spontaneous pneumothorax is unknown,

but established risk factors include: male sex, smoking, a family history of pneumothorax.

Usually occurs in young healthy adult men 85% patients are less than 40 years old Male : female ratio is 6:1 Bilateral in 10% of cases Occurs as result of rupture of an acquired subpleural bleb Blebs have no epithelial lining and arise from rupture of the alveolar

wall Apical blebs found in 85% of patients undergoing thoracotomy Frequency of spontaneous pneumothorax increases after each

episode Most recurrences occur within 2 years of the initial episode

A schematic drawing of a bulla and a bleb, two lung abnormalities that may rupture and lead to pneumothorax.

• Secondary spontaneous pneumothorax: (SSP) Accounts for 10-20% of spontaneous pneumothorax can be due to: COPD- 70% of cases. Diseases of the airways:- COPD (especially when emphysema and lung bullae are present)- Acute severe asthma - Cystic fibrosis. Infections of the lung :

- Pneumocystis pneumonia (PCP)- Tuberculosis- Necrotizing pneumonia. Interstitial lung disease :

- Sarcoidosis- Idiopathic pulmonary fibrosis- Histiocytosis X- Lymphangioleiomyomatosis (LAM)

Connective tissue diseases :

- RA- Ankylosingspondylitis- polymyositis - dermatomyositis Cancer like sarcomas involving the lung Hereditary conditions like:- Marfan's syndrome,- homocystinuria, - Ehlers–Danlos syndrome,- alpha 1-antitrypsin deficiency (which leads to emphysema), - Birt–Hogg–Dubé syndrome In children: - Measles - Echinococcosis- Inhalation of a foreign body- Certain congenital malformations.

• Catamenial pneumothorax: Catamenial pneumothorax refers to the development of

pneumothorax at the time of menstruation. represents 3-6% of spontaneous pneumothorax in women. Typically, it occurs in women aged 30-40 years with a history of pelvic

endometriosis (20-40%). It usually affects the right lung (90-95%) and occurs within 72 hours

after the onset of menses. The recurrence rate in women receiving hormonal treatment is 50%

at 1 year.

• Traumatic pneumothorax: Result from blunt trauma or penetrating injury to the chest wall. The most common mechanism is due to sharp bony points at a

new rib fracture penetrating pleura and damaging lung tissue. Exposure to an explosive blast

Knife or gunshot wounds Blunt trauma from a blow or car crash Deployment of a vehicle's air bag Ruptured air blisters

Small air blisters (blebs) can develop on the top of your lung. It's uncertain why these blebs appear on some people's lungs and not others, but they occur more often on the lungs of people who are tall and thin. Blebs themselves do not constitute a disease of the lungs. While most blebs rupture for no apparent reason, they can rupture from changes in air pressure when you're:

• Scuba diving• Flying• Mountain climbing at high altitudes

• Iatrogenic pneumothorax: Medical conditions like:- Cardiopulmonary resuscitation (CPR)- The insertion of chest tubes

- Taking biopsy samples from lung tissue, may lead to pneumothorax- Pneumonectomy - Thoracocentesis - High-pressure mechanical ventilation - Subclavian venous cannulation- Mechanical ventilation:

A severe type of pneumothorax can occur in people who need mechanical assistance to breathe. The action of the ventilator, which pushes and pulls air in and out of the lungs, can create an imbalance of air pressure within the chest. The lung may collapse completely and the heart may be squeezed to the point that it can't work properly. A severe pneumothorax is a medical emergency and can be fatal.

• Clinical features:

• Predominant symptom is acute pleuritic chest pain • Dyspnoea results form pulmonary compression • Symptoms are proportional to the size of the pneumothorax • Also depend on the degree of pulmonary reserve • On physical examination: Breath sounds may be diminished on the affected side Percussion of the chest may be perceived as hyperresonant (like a booming drum) Vocal resonance and Tactile fremitus can both be noticeably decreased.

• Physical signs include – Tachypnoea – Increased resonance – Absent breath sounds – Hypoxemia (decreased blood oxygen levels) – Cyanosis – Hypercapnia

• In a tension pneumothorax , Chest pain and respiratory distress Tachycardia Tachypnea in the initial stages. Other findings may include:- quieter breath sounds on one side of the chest- low oxygen levels and blood pressure- displacement of the trachea away from the affected side- Rarely, cyanosis- altered level of consciousness- a hyperresonant percussion note on examination of the affected side with

hyperexpansion and decreased movement- pain in the epigastrium (upper abdomen), - displacement of the apex beat (heart impulse), and resonant sound when

tapping the sternum- This is amedical emergency and may require immediate treatment without

further investigations- raised jugular venous pressure (distended neck veins)

• Pathophysiology:• The thoracic cavity is the space inside the chest that contains the lungs, heart and a

number of major blood vessels• On each side of the cavity, a pleural membrane covers the surface of

lung.Normally, the two layers are separated only by a small amount of lubricating serous fluid.

• The lungs are fully inflated within the cavity because the pressure inside the airways is higher than the pressure inside the pleural space.

• Despite the low pressure in the pleural space, air does not enter it because there are no natural connections to an air-containing passage, and the pressure of gases in the bloodstream is too low for them to be forced into the pleural space.

• Therefore, a pneumothorax can only develop if air is allowed to enter, through damage to the chest wall or damage to the lung itself, or occasionally because microorganisms in the pleural space produce gas.

• Chest wall defects are usually evident in cases of injury to the chest wall, such as stab or bullet wounds ("open pneumothorax").

• In secondary spontaneous pneumothoraces, vulnerabilities in the lung tissue are caused by a variety of disease processes, particularly by rupturing of bullae (large air-containing lesions) in cases of severe emphysema.

• Areas of necrosis (tissue death) may precipitate episodes of pneumothorax, although the exact mechanism is unclear.

blebs

• Primary spontaneous pneumothorax has for many years been thought to be caused by "blebs" (small air-filled lesions just under the pleural surface), which were presumed to be more common in those classically at risk of pneumothorax (tall males) due to mechanical factors.

• PSP may also be caused by areas of disruption (porosity) in the pleural layer, which are prone to rupture.

• Smoking may additionally lead to inflammation and obstruction of small airways, accounting for the markedly increased risk of PSP in smokers.

• Once air has stopped entering the pleural cavity, it is gradually resorbed spontaneously.

• Tension pneumothorax occurs when the opening that allows air to enter the pleural space functions as a one way valve, allowing more air to enter with every breath and but not to escape.

• The body compensates by increasing the respiratory rate and tidal volume (size of each breath), worsening the problem. Unless corrected, hypoxia (decreased oxygen levels) and respiratory arrest eventually follow.

• Diagnosis:• The symptoms of pneumothorax can be vague and

inconclusive, especially in those with a small PSP, and confirmation with medical imaging is usually required.

• Chest X-ray• Traditionally a plain radiograph of the chest, ideally with the X-

ray beams being projected from the back (posteroanterior, or "PA"), has been the most appropriate first investigation.

• Performed during maximal inspiration (holding one's breath)• The characteristics of pneumothorax- Pleural line- No lung markings• Outer margin of visceral pleura is separated from parietal

pleura by a lucent gas space devoid of pulmonary vessels

• Quantification of size:- Small: a visible rim of <2 cm between the lung margin and the chest

wall.- Large: a visible rim of >2 cm between the lung margin and the chest

wall.

• CT Scanning• In some lung diseases, especially emphysema, it is possible for abnormal lung

areas such as bullae (large air-filled sacs) to have the same appearance as a pneumothorax on chest X-ray, and it may not be safe to apply any treatment before the distinction is made and before the exact location and size of the pneumothorax is determined.

• In trauma, where it may not be possible to perform an upright film, chest radiography may miss up to a third of pneumothoraces, while CT remains very sensitive.

• A further use of CT is in the identification of underlying lung lesions. • In presumed primary pneumothorax, it may help to identify blebs or cystic

lesions and in secondary pneumothorax it can help to identify most of the causes listed above

• Ultrasound• Ultrasound is commonly used in the evaluation of people who

have sustained physical trauma.• Ultrasound may be more sensitive than chest X-rays in the

identification of pneumothorax after blunt trauma to the chest.• Ultrasound may also provide a rapid diagnosis in other

emergency situations, and allow the quantification of the size of the pneumothorax.

• Several particular features on ultrasonography of the chest can be used to confirm or exclude the diagnosis.

• Management:• The treatment of pneumothorax depends on a number

of factors, and may vary from discharge with early follow-up to immediate needle decompression or insertion of a chest tube.

• Treatment is determined by the severity of symptoms and indicators of acute illness, the presence of underlying lung disease, the estimated size of the pneumothorax on X-ray, and - in some instances - on the personal preference of the person involved.

• Goals:- To promote lung expansion.- To eliminate pathogenesis.- To decrease pneumothorax reoccurence.

• Conservative• Small spontaneous pneumothoraces do not always require

treatment, as they are unlikely to proceed to respiratory failure or tension pneumothorax, and generally resolve spontaneously.

• This approach is most appropriate if the estimated size of the pneumothorax is small, there is no breathlessness, and there is no underlying lung disease.

• It may be appropriate to treat a larger PSP conservatively if the symptoms are limited

• Secondary pneumothoraces are only treated conservatively if the size is very small (1 cm or less air rim) and there are limited symptoms.

• Admission to the hospital is usually recommended.• Oxygen given at a high flow rate may accelerate resorption as

much as fourfold.

• Aspiration:• Simple aspiration is recommended as the first line of treatment

for all PSP.• This involves the administration of local anesthetic and

inserting a needle connected to a three-way tap; up to 2.5 liters of air (in adults) are removed.

• If there has been significant reduction in the size of the pneumothorax on subsequent X-ray, the remainder of the treatment can be conservative. This approach has been shown to be effective in over 50% of cases.

• Aspiration may also be considered in secondary pneumothorax of moderate size (air rim 1–2 cm) without breathlessness, with the difference that ongoing observation in hospital is required even after a successful procedure.

• Moderately sized iatrogenic traumatic pneumothoraces (due to medical procedures) may initially be treated with aspiration.

• Intercostal drainage:

• Definition:• A chest tube (chest drain, thoracic catheter, tube thoracostomy, or intercostal drain) is a flexible

plastic tube that is inserted through the chest wall and into the pleural space or mediastinum. • It is used to remove air (pneumothorax) or fluid (pleural effusion, blood, chyle), or pus (empyema)

from the intrathoracic space. It is also known as a Bülau drain or an intercostal catheter.

• Indications:• Pneumothorax- SSP- Unstable pneumothorax- Severe dyspnoea- Lung collapse- Frequent recurrent pneumothorax- Simple or catheter aspiration drainage is unsuccessful in controlling

symptoms.• Pleural effusion

– Chylothorax– Empyema– Hemothorax– Hydrothorax– Postoperative: for example, thoracotomy, oesophagectomy, cardiac surgery

• Contraindications• Refractory coagulopathy• Presence of a diaphragmatic hernia• Hepatic hydrothorax.• Additional contraindications include scarring in the pleural space

(adhesions).

• Position of intercostal tube:• The chest tube should be positioned in the uppermost part of pleural

space, where residual sir accumulates.• This procedure permits the air to be evacuated from the pleural

space rapidly.• The site of chest tube insertion is in the midclavicular line of second

and third intercostal or anterior axillary line of fifth or sixth intercostal space.

• Observation of drainage:• No bubble released.• The lung reexpansion.• The chest tube is obstructed by blood clot or secretion.• The chest tube shifts to chest wall, the hole of chest tube is located in the chest wall.• If lung reexpands, remove the chest tube 24 hours after reexpansion.• Otherwise, the chest tube will be inserted again or regulated the position.

• Complications• Hemorrhage• Infection • Reexpansion pulmonary edema• Injury to the liver, spleen or diaphragm is possible if the tube is placed inferior to the

pleural cavity. • Injuries to the thoracic aorta and heart can also occur.• Minor complications include a subcutaneous hematoma or seroma, anxiety, shortness

of breath (dyspnea), and cough (after removing large volume of fluid)• Subcutaneous emphysema indicates backpressure created by a clogged drain or

insufficient negative pressure.• Chest tube clogging

Chest Tube Drainage Holes

Cross-Section of a Channel Drain

Size of Chest Tube:Adult or Teen Male = 28–32 Fr ( french catheter scale)Pp Adult or Teen Female = 28 FrChild = 18 FrNewborn = 12–14 Fr

• Pleurodesis:• Goals:1. Prevention of pneumothorax reoccurence.2. To produce inflammation of pleura and adhesions.• Indications: Persist air-leak and repeated pneumothorax Bilateral pneumothoraces Bullae Lung dysfuntion• Sclerosing agents like:- Tetracycline- Monocycline- Doxycline- Talc- ErythromycinAre instilled into the pleural space should lead to an aseptic inflammation

with dense adhesions, leading ultimately to pleural symphysis.