A pulmonary laceration is a
chest injury
A chest injury, also known as chest trauma, is any form of physical injury to the chest including the ribs, heart and lungs. Chest injuries account for 25% of all deaths from traumatic injury. Typically chest injuries are caused by blunt mechanism ...
in which
lung
The lungs are the primary organs of the respiratory system in humans and most other animals, including some snails and a small number of fish. In mammals and most other vertebrates, two lungs are located near the backbone on either side of t ...
tissue is torn or cut.
[
] An injury that is potentially more serious than
pulmonary contusion
A pulmonary contusion, also known as lung contusion, is a bruise of the lung, caused by chest trauma. As a result of damage to capillaries, blood and other fluids accumulate in the lung tissue. The excess fluid interferes with gas exchange, pot ...
, pulmonary
laceration
A wound is a rapid onset of injury that involves lacerated or punctured skin (an ''open'' wound), or a contusion (a ''closed'' wound) from blunt force trauma or compression. In pathology, a ''wound'' is an acute injury that damages the epiderm ...
involves disruption of the architecture of the lung,
[
] while pulmonary contusion does not.
Pulmonary laceration is commonly caused by
penetrating trauma
Penetrating trauma is an open wound injury that occurs when an object pierces the skin and enters a tissue of the body, creating a deep but relatively narrow entry wound. In contrast, a blunt or ''non-penetrating'' trauma may have some deep dama ...
but may also result from forces involved in
blunt trauma
Blunt trauma, also known as blunt force trauma or non-penetrating trauma, is physical traumas, and particularly in the elderly who fall. It is contrasted with penetrating trauma which occurs when an object pierces the skin and enters a tissue ...
such as
shear stress
Shear stress, often denoted by (Greek: tau), is the component of stress coplanar with a material cross section. It arises from the shear force, the component of force vector parallel to the material cross section. ''Normal stress'', on the ot ...
. A cavity filled with blood, air, or both can form.
The injury is diagnosed when collections of air or fluid are found on a
CT scan of the chest. Surgery may be required to stitch the laceration, to drain blood, or even to remove injured parts of the lung. The injury commonly heals quickly with few problems if it is given proper treatment; however it may be associated with scarring of the lung or other complications.
Presentation
Complications
Complications are not common but include infection,
lung abscess
Lung abscess is a type of liquefactive necrosis of the lung tissue and formation of cavities (more than 2 cm) containing necrotic debris or fluid caused by microbial infection.
This pus-filled cavity is often caused by aspiration, which may ...
, and
bronchopleural fistula A bronchopleural fistula (BPF) is a fistula between the pleural space and the lung. It can develop following pneumonectomy, lung ablation, post-traumatically, or with certain types of infection. It may also develop when large airways are in communi ...
(a
fistula
A fistula (plural: fistulas or fistulae ; from Latin ''fistula'', "tube, pipe") in anatomy is an abnormal connection between two hollow spaces (technically, two epithelialized surfaces), such as blood vessels, intestines, or other hollow or ...
between the
pleural space
The pleural cavity, pleural space, or interpleural space is the potential space between the pleurae of the pleural sac that surrounds each lung. A small amount of serous pleural fluid is maintained in the pleural cavity to enable lubrication bet ...
and the
bronchial tree).
A bronchopleural fistula results when there is a communication between the laceration, a bronchiole, and the pleura; it can cause air to leak into the pleural space despite the placement of a chest tube.
The laceration can also enlarge, as may occur when the injury creates a valve that allows air to enter the laceration, progressively expanding it.
One complication,
air embolism
An air embolism, also known as a gas embolism, is a blood vessel blockage caused by one or more bubbles of air or other gas in the circulatory system. Air can be introduced into the circulation during surgical procedures, lung over-expansion i ...
, in which air enters the bloodstream, is potentially fatal, especially when it occurs on the left side of the heart.
Air can enter the circulatory system through a damaged
vein
Veins are blood vessels in humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated b ...
in the injured chest and can travel to any organ; it is especially deadly in the heart or brain.
Positive pressure ventilation
Modes of mechanical ventilation are one of the most important aspects of the usage of mechanical ventilation. The mode refers to the method of inspiratory support. In general, mode selection is based on clinician familiarity and institutional pref ...
can cause pulmonary embolism by forcing air out of injured lungs and into blood vessels.
Causes
Pulmonary laceration is a common result of
penetrating trauma
Penetrating trauma is an open wound injury that occurs when an object pierces the skin and enters a tissue of the body, creating a deep but relatively narrow entry wound. In contrast, a blunt or ''non-penetrating'' trauma may have some deep dama ...
but may also be caused by
blunt trauma
Blunt trauma, also known as blunt force trauma or non-penetrating trauma, is physical traumas, and particularly in the elderly who fall. It is contrasted with penetrating trauma which occurs when an object pierces the skin and enters a tissue ...
;
broken ribs may perforate the lung, or the tissue may be torn due to
shearing force
In solid mechanics, shearing forces are unaligned forces acting on one part of a Rigid body, body in a specific direction, and another part of the body in the opposite direction. When the forces are collinear (aligned with each other), they ...
s
[
] that result from different rates of acceleration or deceleration of different tissues of the lung.
Violent compression of the chest can cause lacerations by rupturing or shearing the lung tissue.
[
] Pulmonary laceration may result from blunt and penetrating forces that occur in the same injury and may be associated with pulmonary contusion.
[
][
] Lacerations of the lung tissue can also occur by compression of the alveoli against the ribs or spine.
As with contusions, pulmonary lacerations usually occur near solid structures in the chest such as ribs.
Pulmonary laceration is suspected when rib fractures are present.
Pathophysiology
![Pneumothorax CT](https://upload.wikimedia.org/wikipedia/commons/5/57/Pneumothorax_CT.jpg)
A pulmonary laceration can cause air to leak out of the lacerated lung
[
] and into the
pleural space
The pleural cavity, pleural space, or interpleural space is the potential space between the pleurae of the pleural sac that surrounds each lung. A small amount of serous pleural fluid is maintained in the pleural cavity to enable lubrication bet ...
, if the laceration goes through to it.
Pulmonary laceration invariably results in
pneumothorax
A pneumothorax is an abnormal collection of air in the pleural space between the lung and the chest wall. Symptoms typically include sudden onset of sharp, one-sided chest pain and shortness of breath. In a minority of cases, a one-way valve ...
(due to torn
airway
The respiratory tract is the subdivision of the respiratory system involved with the process of respiration in mammals. The respiratory tract is lined with respiratory epithelium as respiratory mucosa.
Air is breathed in through the nose to th ...
s),
hemothorax
A hemothorax (derived from hemo- lood+ thorax hest plural ''hemothoraces'') is an accumulation of blood within the pleural cavity. The symptoms of a hemothorax may include chest pain and difficulty breathing, while the clinical signs may incl ...
(due to torn
blood vessel
The blood vessels are the components of the circulatory system that transport blood throughout the human body. These vessels transport blood cells, nutrients, and oxygen to the tissues of the body. They also take waste and carbon dioxide away ...
s), or a
hemopneumothorax
Hemopneumothorax, or haemopneumothorax, is the condition of having both air (pneumothorax) and blood (hemothorax) in the chest cavity. A hemothorax, pneumothorax, or the combination of both can occur due to an injury to the lung or chest.
Cause
T ...
(with both blood and air in the chest cavity).
[
] Unlike hemothoraces that occur due to pulmonary contusion, those due to lung laceration may be large and long lasting.
However, the lungs do not usually bleed very much because the blood vessels involved are small and the pressure within them is low.
Therefore, pneumothorax is usually more of a problem than hemothorax.
A pneumothorax may form or be turned into a
tension pneumothorax
A pneumothorax is an abnormal collection of air in the pleural space between the lung and the chest wall. Symptoms typically include sudden onset of sharp, one-sided chest pain and shortness of breath. In a minority of cases, a one-way valve is ...
by
mechanical ventilation
Mechanical ventilation, assisted ventilation or intermittent mandatory ventilation (IMV), is the medical term for using a machine called a ventilator to fully or partially provide artificial ventilation. Mechanical ventilation helps move air ...
, which may force air out of the tear in the lung.
The laceration may also close up by itself, which can cause it to trap blood and potentially form a
cyst
A cyst is a closed sac, having a distinct envelope and cell division, division compared with the nearby Biological tissue, tissue. Hence, it is a cluster of Cell (biology), cells that have grouped together to form a sac (like the manner in which ...
or
hematoma
A hematoma, also spelled haematoma, or blood suffusion is a localized bleeding outside of blood vessels, due to either disease or trauma including injury or surgery and may involve blood continuing to seep from broken capillary, capillaries. A he ...
.
Because the lung is elastic, the tear forms a round cyst called a ''traumatic air cyst'' that may be filled with air, or blood and air, and that usually shrinks over a period of weeks or months.
[
] Lacerations that are filled with air are called
pneumatoceles, and those that are filled with blood are called
pulmonary hematoma
A pulmonary hematoma is a collection of blood within the tissue of the lung. It may result when a pulmonary laceration fills with blood. A lung laceration filled with air is called a pneumatocele. In some cases, both pneumatoceles and hematoma ...
s.
In some cases, both pneumatoceles and hematomas exist in the same injured lung.
A pneumatocele can become enlarged, for example when the patient is mechanically ventilated or has
acute respiratory distress syndrome
Acute respiratory distress syndrome (ARDS) is a type of respiratory failure characterized by rapid onset of widespread inflammation in the lungs. Symptoms include shortness of breath (dyspnea), rapid breathing (tachypnea), and bluish skin colo ...
, in which case it may not go away for months.
Pulmonary hematomas take longer to heal than simple pneumatoceles and commonly leave the lungs scarred.
[
]
Over time, the walls of lung lacerations tend to grow thicker due to edema and bleeding at the edges.
Diagnosis
![Pulmonary contusion](https://upload.wikimedia.org/wikipedia/commons/f/f2/Pulmonary_contusion.jpg)
Pulmonary laceration may not be visible using
chest X-ray
A chest radiograph, called a chest X-ray (CXR), or chest film, is a projection radiograph of the chest used to diagnose conditions affecting the chest, its contents, and nearby structures. Chest radiographs are the most common film taken in med ...
because an associated
pulmonary contusion
A pulmonary contusion, also known as lung contusion, is a bruise of the lung, caused by chest trauma. As a result of damage to capillaries, blood and other fluids accumulate in the lung tissue. The excess fluid interferes with gas exchange, pot ...
or
hemorrhage
Bleeding, hemorrhage, haemorrhage or blood loss, is blood escaping from the circulatory system from damaged blood vessels. Bleeding can occur internally, or externally either through a natural opening such as the mouth, nose, ear, urethra, vag ...
may mask it.
As the lung contusion clears (usually within two to four days), lacerations begin to become visible on chest X-ray.
[
] CT scanning is more sensitive and better at detecting pulmonary laceration than
X-ray
An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30&nb ...
s are,
[
] and often reveals multiple lacerations in cases where chest X-ray showed only a contusion.
Before CT scanning was widely available, pulmonary laceration was considered unusual because it was not common to find with X-ray alone.
On a CT scan, pulmonary lacerations show up in a contused area of the lung,
[
] typically appearing as cavities filled with air or fluid
[
] that usually have a round or ovoid shape due to the lung's elasticity.
Hematomas appear on chest radiographs as smooth masses that are round or ovoid in shape.
Like lacerations, hematomas may initially be hidden on X-ray by lung contusions, but they become more apparent as the contusion begins to heal.
Pneumatoceles have a similar shape to that of hematomas but have thin, smooth walls.
[
] Lacerations may be filled completely with blood, completely with air, or partially with both.
Lacerations filled with both blood and air display a distinctive air-fluid level.
A single laceration may occur by itself, or many may be present, creating an appearance like Swiss cheese in the radiography of the lung.
Pulmonary laceration is usually accompanied by
hemoptysis
Hemoptysis is the coughing up of blood or blood-stained mucus from the bronchi, larynx, trachea, or lungs. In other words, it is the airway bleeding. This can occur with lung cancer, infections such as tuberculosis, bronchitis, or pneumonia, and ...
(coughing up blood or of blood-stained sputum).
[
]
Thoracoscopy
Thoracoscopy is a medical procedure involving internal examination, biopsy and/or resection/drainage of disease or masses within the pleural cavity, usually with video assistance. Thoracoscopy may be performed either under general anaesthesia o ...
may be used in both diagnosis and treatment of pulmonary laceration.
A healing laceration may resemble a
lung nodule
A lung nodule or pulmonary nodule is a relatively small focal density in the lung. A solitary pulmonary nodule (SPN) or coin lesion, is a mass in the lung smaller than three centimeters in diameter. A pulmonary micronodule has a diameter of less th ...
on radiographs, but unlike pulmonary nodules, lacerations decrease in size over time on radiographs.
Classification
In 1988, a group led by R.B. Wagner divided pulmonary lacerations into four types based on the manner in which the person was injured and indications found on a
CT scan.
[
] In type 1 lacerations, which occur in the mid lung area, the air-filled lung bursts as a result of sudden compression of the chest.
Also called compression-rupture lacerations, type 1 are the most common type and usually occur in a central location of the lung.
They tend to be large, ranging in size from 2–8 cm.
[
] The shearing stress in type 2 results when the lower chest is suddenly compressed and the lower lung is suddenly moved across the
vertebra
The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic ...
l bodies.
Type 2, also called compression-shear,
tends to occur near the spine and have an elongated shape.
Type 2 lacerations usually occur in younger people with more flexible chests.
[
] Type 3, which are caused by punctures from fractured ribs, occur in the area near the chest wall underlying the broken rib.
Also called rib penetration lacerations, type 3 lacerations tend to be small
and accompanied by pneumothorax.
Commonly, more than one type 3 laceration will occur.
Type 4, also called adhesion tears,
occur in cases where a
pleuropulmonary adhesion had formed prior to the injury, in which the chest wall is suddenly fractured or pushed inwards.
They occur in the
subpleural area and result from shearing forces at sites of transpleural adhesion.
Treatment
As with other chest injuries such as pulmonary contusion, hemothorax, and pneumothorax, pulmonary laceration can often be treated with just supplemental oxygen, ventilation, and drainage of fluids from the chest cavity.
[
] A
thoracostomy tube
A chest tube (also chest drain, thoracic catheter, tube thoracostomy or intercostal drain) is a surgical drain that is inserted through the chest wall and into the pleural space or the mediastinum in order to remove clinically undesired substance ...
can be used to remove blood and air from the chest cavity.
[
] About 5% of cases require surgery, called
thoracotomy
A thoracotomy is a surgical procedure to gain access into the pleural space of the chest. It is performed by surgeons (emergency physicians or paramedics under certain circumstances) to gain access to the thoracic organs, most commonly the hea ...
.
Thoracotomy is especially likely to be needed if a lung fails to re-expand; if pneumothorax, bleeding, or coughing up blood persist; or in order to remove clotted blood from a hemothorax.
Surgical treatment includes suturing,
stapling, oversewing, and wedging out of the laceration.
Occasionally, surgeons must perform a
lobectomy
Lobectomy means ''surgical excision of a lobe''. This may refer to a lobe of the lung (also simply called a lobectomy), a lobe of the thyroid (hemithyroidectomy), a lobe of the brain (as in anterior temporal lobectomy), or a lobe of the liver (h ...
, in which a lobe of the lung is removed, or a
pneumonectomy
A pneumonectomy (or pneumectomy) is a surgical procedure to remove a lung first successfully done in 1933 by Dr. Evarts Graham. This is not to be confused with a lobectomy or segmentectomy, which only removes one part of the lung.
There are two ...
, in which an entire lung is removed.
Prognosis
Full recovery is common with proper treatment.
Pulmonary laceration usually heals quickly after a chest tube is inserted and is usually not associated with major long-term problems.
Pulmonary lacerations usually heal within three to five weeks,
and lacerations filled with air will commonly heal within one to three weeks but on occasion take longer.
However, the injury often takes weeks or months to heal, and the lung may be
scar
A scar (or scar tissue) is an area of fibrous tissue that replaces normal skin after an injury. Scars result from the biological process of wound repair in the skin, as well as in other organs, and tissues of the body. Thus, scarring is a na ...
red.
Small pulmonary lacerations frequently heal by themselves if material is removed from the
pleura
The pulmonary pleurae (''sing.'' pleura) are the two opposing layers of serous membrane overlying the lungs and the inside of the surrounding chest walls.
The inner pleura, called the visceral pleura, covers the surface of each lung and dips bet ...
l space, but surgery may be required for larger lacerations that do not heal properly or that bleed.
See also
*
Pulmonary toilet Pulmonary hygiene, formerly referred to as pulmonary toilet,
is a set of methods used to clear mucus and secretions from the airways. The word ''pulmonary'' refers to the lungs. The word ''toilet'', related to the French ''toilette'', refers to ...
References
External links
{{DEFAULTSORT:Pulmonary Laceration
Medical emergencies
Chest trauma
Lung disorders