Pleura

By:Sharmin Susiwala

TY BPTCTS

• Each lung is invested by an exceedingly delicate serous membrane, the pleura, which is arranged in the form of a closed invaginated sac.

Each pleura has two parts: Parietal layer Visceral layer

• A portion of the serous membrane covers the surface of the lung and dips into the fissures between its lobes; it is called the pulmonary pleura( or visceral pleura).

• The rest of the membrane lines the inner surface of the chest wall, covers the diaphragm, and is reflected over the structures occupying the middle of the thorax; this portion is termed the parietal pleura.

• The two layers are continuous with one another around and below the root of the lung; in health they are in actual contact with one another, but the potential space between them is known as the pleural cavity.

Parietal pleura• The portion of the pleura external to the pulmonary pleura lines the

inner surface of the chest wall, covers the diaphragm, and is reflected over the structures occupying the middle of the thorax; this portion is termed the parietal pleura.

• Parietal pleura lines the thoracic wall, covers the superior surface of the diaphragm and separates the pleural cavity from the mediastinum.

• Different portions of the parietal pleura have received special names which indicate their position:

thus, that portion which lines the inner surfaces of the ribs and Intercostales is the costal pleura;

that clothing the convex surface of the diaphragm is the diaphragmatic pleura;

that which rises into the neck, over the summit of the lung, is the cupula of the pleura (cervical pleura); and

that which is applied to the other thoracic viscera is the mediastinal pleura.

RECESSES OF PLEURA

Recesses of pleura

• Costodiaphragmatic Recess: The lower area of the pleural cavity into which the lung expands

on inspiration is referred to as the costodiaphragmatic recess. Are slitlike spaces between the costal and diaphragmatic

parietal pleura Separated only by a capillary layer of pleural fluid During inspiration, the lower margins of the lungs descend into

the recesses During expiration, the lower margins of the lungs ascend so that

the costal and diaphragmatic pleurae come together again Pleural effusions collect in the costodiaphragmatic recess when

in standing position.

• Costomediastinal Recesses: Are situated along the anterior margins of the pleura They are slitlike spaces between the costal and the

mediastinal parietal pleurae Separated by a capillary layer of pleural fluid During inspiration and expiration, the anterior borders

of the lungs slide in and out of the recesses

Visceral Pleura

• The visceral pleura is attached directly to the lungs, as opposed to the parietal pleura, which is attached to the opposing thoracic cavity.

• The space between these two delicate membranes is known as the intrapleural space (pleural cavity).

• The inner pleura (visceral pleura) covers the lungs and adjoining structures, viz. blood vessels, bronchi and nerves.

Pulmonary Ligament • The root of the lung is covered in

front, above, and behind by pleura, and that at its lower border the investing layers come into contact.

• Here they form a sort of mesenteric fold, the pulmonary ligament, which extends between the lower part of the mediastinal surface of the lung and the pericardium.

• Just above the diaphragm the ligament ends in a free falciform border.

• It serves to retain the lower part of the lung in position.

Nerve Supply Parietal pleura::: The parietal pleura is sensitive to pain, temperature, touch and

pressure, and is supplied as follows: The costal pleura is segmentally supplied by the intercostal nerves The mediastinal pleura is supplied by the phrenic nerve The diaphragmatic pleura is supplied over the domes by the phrenic

nerve and around the periphery by the lower six intercostal nerves Visceral pleura::: The visceral pleura covering the lungs is sensitive to stretch It is insensitive to common sensations such as pain and touch It receives an autonomic nerve supply from the pulmonary plexus

Pleural Fluid The pleural space normally contains 5 to 10 ml of clear fluid It lubricates the opposing surfaces of the visceral and parietal pleurae during

respiration The formation of the fluid results from hydrostatic and osmotic pressures

between the capillaries The pleural fluid is normally absorbed into the capillaries of the visceral

pleura Any condition that increases the production of the fluid or impairs the

drainage of the fluid results in the abnormal accumulation of fluid, called pleural effusion

The presence of 300 ml of fluid in the costodiaphragmatic recess in an adult is sufficient to enable its clinical detection

The clinical signs include decreased lung expansion on the side of the effusion, with decreased breath sounds and dullness on percussion over the effusion

Diseases of Pleura

Pleurisy

• Definition:“Pleurisy (also known as pleuritis) is an inflammation of the pleura, the

lining of the pleural cavity surrounding the lungs.”

• Signs and symptoms: The main symptom of pleurisy is a sharp or stabbing pain in the chest

that gets worse with deep breathing, coughing, sneezing or laughing. The inflamed pleural layers rub against each other every time the

lungs expand to breathe in air. This can cause severe sharp pain with inhalation (also called pleuritic chest pain).

The pain may stay in one place, or it may spread to the shoulder or back. Sometimes it becomes a fairly constant dull ache.

Depending on its cause, pleurisy may be accompanied by other symptoms:

Shortness of breath Cough Fever and chills

Rapid, shallow breathing Unexplained weight loss Sore throat followed by pain and swelling in the joints Diarrhea Ventricular tachycardia Coughing up blood

• Causes:o Viral infection is the most common cause of pleurisy. o However, many different conditions can cause pleurisy:• Pneumothorax• Bacterial infections like pneumonia and tuberculosis• Autoimmune disorders like systemic lupus erythematosus (or drug-induced

lupus erythematosus) and rheumatoid arthritis• Lung cancer and lymphoma• Other lung diseases like Cystic

Fibrosis, sarcoidosis, asbestosis, lymphangioleiomyomatosis, and mesothelioma

• Pulmonary embolism, a blood clot in the blood vessels that go into the lungs

• Inflammatory bowel disease• Familial Mediterranean fever, an inherited condition that often causes fever and swelling

in the abdomen or lung• Infection from a fungus or parasite• Heart surgery, especially coronary artery bypass grafting• High blood pressure• Chest injuries• Aortic dissection• Can occur with no illness or infection• Some cases of pleurisy are idiopathic

• Diagnosis:A diagnosis of pleurisy or another pleural condition is based on medical histories, physical

exams, and diagnostic tests. The goals are to rule out other sources of the symptoms and to find the cause of the pleurisy so the underlying disorder can be treated.

• Physical exam---• A doctor uses a stethoscope to listen to the breathing. • This detects any unusual sounds in the lungs. • A person with pleurisy will have inflamed layers of the pleura that make a rough, scratchy

sound as they rub against each other during breathing. This is called pleural friction rub, and it is a likely sign of pleurisy.

• Diagnostic tests---1. Chest x-ray• A chest x-ray takes a picture of the heart and lungs. It may show air or fluid in the

pleural space. It also may show what's causing the pleurisy –for example; pneumonia, a fractured rib, or a lung tumor.

• Sometimes an x-ray is taken while lying on the painful side. This may show fluid that did not appear on the upright x-ray as well as showing changes in fluid position.

2. Computed tomography (CT) scan• A CT scan provides a computer-generated picture of the lungs that can show pockets of

fluid. It also may show signs of pneumonia, a lung abscess, or a tumor.3. Ultrasound• Ultrasonography uses sound waves to create an image. It may show where fluid is

located in the chest. It also can show some tumors. Although ultrasound may detect fluid around the lungs, also known as a pleural effusion, sounds beams cannot penetrate through air or bone. Therefore, an actual picture of the lungs cannot be obtained with ultrasonography.

4. Magnetic resonance imaging (MRI)• Magnetic resonance imaging(MRI), also called nuclear magnetic resonance (NMR)

scanning, uses powerful magnets to show pleural effusions and tumors.5. Blood tests• Blood tests can detect bacterial or viral infection, pneumonia, rheumatic fever,

a pulmonary embolism, or lupus.

6. Arterial blood gas• In arterial blood gas sampling a small amount of blood is taken from an artery

usually in the wrist. The blood is then checked for oxygen and carbon dioxide levels. This test shows how well the lungs are taking in oxygen.

7. Thoracentesis• The person sits upright and leans on a table. Excess fluid from the pleural space is

drained into a bag.• Once the presence and location of fluid is confirmed, a sample of fluid can be

removed for testing. The procedure to remove fluid in the chest is called thoracentesis.

• The doctor inserts a small needle or a thin, hollow, plastic tube through the ribs in the back of the chest into the chest wall and draws fluid out of the chest.

• Thoracentesis can be done in the doctor's office or at the hospital. Ultrasound is used to guide the needle to the fluid that is trapped in small pockets around the lungs.

• Thoracentesis usually does not cause serious complications. Generally, a chest x-ray is done after the procedure to evaluate the lungs.

8. Pleural biopsy • If tuberculosis or lung cancer is a suspected cause of your condition, your doctor

may perform thoracentesis with pleural biopsy — removal of a sample of tissue to

Thoracentesis

• be examined in a pathology laboratory. The biopsy needle has a small hook on the end that lifts away a small piece of tissue. Your doctor may use ultrasound guidance for this procedure as well.

9. Thoracoscopy. • This procedure, performed while you're under a general anesthetic,

allows a surgeon to see inside your chest and obtain a sample of pleural tissue. First, the surgeon makes one or more small incisions between your ribs. A tube with a tiny video camera is then inserted into your chest cavity - a procedure sometimes called video-assisted thoracoscopic surgery (VATS). Tools designed for this type of surgery allow your surgeon to cut away tissue for testing.

• Treatment: Treatment has several goals:1. Remove the fluid, air, or blood from the pleural space2. Relieve symptoms3. Treat the underlying condition

• Procedures• If large amounts of fluid, air, or blood are not removed from the pleural space, they may put

pressure on the lung and cause it to collapse.• The surgical procedures used to drain fluid, air, or blood from the pleural space are as

follows:• During thoracentesis, a needle or a thin, hollow, plastic tube is inserted through the ribs in

the back of the chest into the chest wall. A syringe is attached to draw fluid out of the chest. This procedure can remove more than 6 cups (1.5 litres) of fluid at a time.

• When larger amounts of fluid must be removed, a chest tube may be inserted through the chest wall. The doctor injects a local painkiller into the area of the chest wall outside where the fluid is. A plastic tube is then inserted into the chest between two ribs. The tube is connected to a box that suctions the fluid out. A chest x-ray is taken to check the tube's position.

• A chest tube also is used to drain blood and air from the pleural space. This can take several days. The tube is left in place, and the patient usually stays in the hospital during this time.

• Sometimes the fluid contains thick pus or blood clots, or it may have formed a hard skin or peel. This makes it harder to drain the fluid. To help break up the pus or blood clots, the doctor may use the chest tube to put certain medicines into the pleural space. These medicines are called fibrinolytics. If the pus or blood clots still do not drain out, surgery may be necessary.

• Medications• A couple of medications are used to relieve pleurisy symptoms:

• Paracetamol (acetaminophen) or anti-inflammatory agents to control pain and decrease inflammation. Only indomethacin (brand name Indocin) has been studied with respect to relief of pleurisy.[2]

• Codeine-based cough syrups to control a cough• There may be a role for the use of corticosteroids (for tuberculous

pleurisy), tacrolimus (Prograf) and methotrexate (Trexall, Rheumatrex) in the treatment of pleurisy.

• Lifestyle changes• Lying on the painful side may be more comfortable• Breathing deeply and coughing to clear mucus as the pain eases. • Getting rest• Treating the cause• Ideally, the treatment of pleurisy is aimed at eliminating the underlying cause of the disease.• If the pleural fluid is infected, treatment involves antibiotics and draining the fluid. If the

infection is tuberculosis or from a fungus, treatment involves long-term use of antibiotics or antifungal medicines.

• If the fluid is caused by tumors of the pleura, it may build up again quickly after it is drained. Sometimes antitumor medicines will prevent further fluid buildup. If they don't, the doctor may seal the pleural space. This is called pleurodesis. Pleurodesis involves the drainage of all the fluid out of the chest through a chest tube. A substance is inserted through the chest tube into the pleural space. This substance irritates the surface of the pleura. This causes the two layers of the pleura to squeeze shut so there is no room for more fluid to build up.

• Chemotherapy or radiation treatment also may be used to reduce the size of the tumors.• If congestive heart failure is causing the fluid buildup, treatment usually includes diuretics

and other medicines.• The most common and known treatment for pleurisy is generally to carry on as normal,

ibuprofen and amoxicilin being common treatments prescribed by doctors. Milder forms of Pleurisy can be noticed by less inflammatres of the arms and legs. If this is the case Pleurisy will clear of all symptoms within two weeks.

• Complications:• Pleurisy is often associated with complications that affect the pleural space.• Pleural effusion• In some cases of pleurisy, excess fluid builds up in the pleural space. This is called a pleural

effusion. The buildup of fluid usually forces the two layers of the pleura apart so they don't rub against each other when breathing. This can relieve the pain of pleurisy. A large amount of extra fluid can push the pleura against the lung until the lung, or a part of it, collapses. This can make it hard to breathe.

• In some cases of pleural effusion, the extra fluid gets infected and turns into an abscess. This is called an empyema.

• Pleural effusion involving fibrinous exudates in the fluid may be called fibrinous pleurisy. It sometimes occurs as a later stage of pleurisy.

• A person can develop a pleural effusion in the absence of pleurisy. For example, pneumonia, heart failure, cancer, or a pulmonary embolism can lead to a pleural effusion.

• Pneumothorax• Air or gas also can build up in the pleural space. This is called a pneumothorax. It

can result from acute lung injury or a lung disease like emphysema. Lung procedures, like surgery, drainage of fluid with a needle, examination of the lung from the inside with a light and a camera, or mechanical ventilation, also can cause a pneumothorax.

• The most common symptom is sudden pain in one side of the lung and shortness of breath. A pneumothorax also can put pressure on the lung and cause it to collapse.

• If the pneumothorax is small, it may go away on its own. If large, a chest tube is placed through the skin and chest wall into the pleural space to remove the air.

• Hemothorax• Blood also can collect in the pleural space. This is called hemothorax. The most

common cause is injury to the chest from blunt force or surgery on the heart or chest. Hemothorax also can occur in people with lung or pleural cancer.

• Hemothorax can put pressure on the lung and force it to collapse. It also can cause shock, a state of hypoperfusion in which an insufficient amount of blood is able to reach the organs.