Respiratory Flashcards
(11 cards)
Upper RTIs
Acute Tracheitis
Bronchitis
Bronchiolitis
Tracheitis
Inflamm of the trachea, usually after nose or throat infection
Bacterial tracheitis is a bacterial infection of the trachea and is capable of producing airway obstruction.
One of the most common causes is Staphylococcus aureus and often follows a recent viral upper respiratory infection. Bacterial tracheitis is a rare complication of influenza infection. It is the most serious in young children, possibly because of the relatively small size of the trachea that gets easily blocked by swelling. The most frequent sign is the rapid development of stridor. It is occasionally confused with croup. If it is inflamed, a condition known as tracheitis can occur. In this condition there can be inflammation of the linings of the trachea. A condition called tracheo-bronchitis can be caused, when the mucous membrane of the trachea and bronchi swell. A collapsed trachea is formed as a result of defect in the cartilage, that makes the cartilage unable to support the trachea and results in dry hacking cough. In this condition there can be inflammation of the linings of the trachea. If the connective nerve tissues in the trachea degenerate it causes tracheomalacia. Infections to the trachea can cause tracheomegaly.
Bronchitis
Bronchitis can be either acute or chronic.
Symptoms of acute bronchitis usually last days to a few weeks. However, bronchitis that lasts up to 90 days is still usually classified as acute bronchitis. Bronchitis that lasts longer, sometimes for months or years, is usually classified as chronic bronchitis. When people say “bronchitis,” they usually mean acute bronchitis.
When chronic bronchitis occurs together with a decrease in the rate of airflow from the lungs when the person breathes out (expiratory airflow), it is considered a defining characteristic of chronic obstructive pulmonary disease (COPD).
Exposure to irritants, such as smoke, smog, dust particles, and fumes (from irritants such as strong acids, ammonia, some organic solvents, chlorine, hydrogen sulfide, sulfur dioxide, and bromine), can also inflame the windpipe and bronchi, causing symptoms similar to those of acute bronchitis.
Bronchitis occurs most often during the winter and is most often caused by viruses. Viral bronchitis may be caused by a number of common viruses, including the influenza virus. Even after a viral infection has cleared up, the irritation it causes can continue to cause symptoms for weeks.
Bronchitis may also be caused by bacteria. Bacterial bronchitis occasionally follows a viral upper respiratory infection. Mycoplasma pneumoniae, Chlamydia pneumoniae, and Bordetella pertussis infection (which causes whooping cough) are among the bacteria that cause acute bronchitis. Bacterial causes of acute bronchitis are more likely when many people are affected (an outbreak).
If people who have chronic lung disorders such as COPD, bronchiectasis, or cystic fibrosis develop inflammation of their trachea and bronchi, the inflammation is considered a flare (exacerbation) of the underlying disorder rather than acute bronchitis.
The onset of cough (usually dry at first) signals the beginning of acute bronchitis. With viral bronchitis, small amounts of white mucus are often coughed up. This mucus often changes from white to green or yellow. The color change does not mean there is a bacterial infection. Color change means only that cells associated with inflammation have moved into the airway and are coloring the sputum.
When bronchitis is severe, fever may be slightly higher at 101° to 102° F (38° to 39° C) and may last for 3 to 5 days, but higher fevers are unusual unless bronchitis is caused by influenza. Cough is the last symptom to subside and often takes 2 to 3 weeks or even longer to do so. Viruses can damage the epithelial cells lining the bronchi, and the body needs time to repair the damage.
Airway hyperreactivity, which is a short-term narrowing of the airways with impairment or limitation of the amount of air flowing into and out of the lungs, is common in acute bronchitis. The impairment of airflow may be triggered by common exposures, such as inhaling mild irritants (for example, perfume, strong odors, or exhaust fumes) or cold air. If the impairment of airflow is severe, the person may be short of breath. Wheezing, especially after coughing, is common.
Older people may have unusual bronchits symptoms, such as confusion or rapid breathing, rather than fever and cough.
Serious complications, such as acute respiratory failure or pneumonia, usually occur only in people who are older, or who have problems with immune defenses.
Diagnosis of Acute Bronchitis
Doctors usually make a diagnosis of bronchitis based on the symptoms. Fevers that are high or prolonged or both could indicate the presence of pneumonia. Doctors may hear wheezing during the physical examination. A chest x-ray is sometimes done to exclude pneumonia, for example, when doctors hear crackles or congestion in the lungs or when the person is short of breath.
A sample taken from the throat or nose can be used to detect influenza viruses or Bordetella pertussis if infections with those organisms seem likely. Sputum is generally only examined if doctors find evidence of pneumonia on a chest x-ray or during the examination. If a cough persists for more than 2 months, a chest x-ray is done to exclude an underlying lung disease, such as lung cancer.
Treatment of Acute Bronchitis
Adults may take aspirin, acetaminophen, or ibuprofen to reduce fever and general feelings of illness, but children should take only acetaminophen or ibuprofen, not aspirin, because children taking aspirin are at higher risk for Reye syndrome. People with acute bronchitis, especially those who have a fever, should drink plenty of fluid.
Antibiotics are not used to treat bronchitis except for people whose infection is caused by bacteria (for example, during an outbreak). When an antibiotic is used, a drug such as azithromycin or clarithromycin is most often given. Antibiotics do not help people with viral bronchitis. Treatment with an antiviral drug for influenza such as oseltamivir or zanamivir may help speed recovery from influenza (whether or not it causes acute bronchitis) if given within 48 hours of the onset of symptoms.
Bronchiolitis
Inflamm of the bronchioles. Usually in children less than 2 years of age. Presents with coughing, wheezing and shortness of breath. Usually caused by repiratory syncitial virus.
COPD
Persistent narrowing (obstruction) of the airways occurring with emphysema, chronic obstructive bronchitis, or both disorders.
Chronic bronchitis is defined as cough that produces sputum repeatedly during two successive years. When chronic bronchitis involves airflow obstruction, it qualifies as chronic obstructive bronchitis.
Emphysema is defined as widespread and irreversible destruction of the alveolar walls (the cells that support the air sacs, or alveoli, that make up the lungs) and enlargement of many of the alveoli.
The small airways (bronchioles) of the lungs contain smooth muscles and are normally held open by their attachments to alveolar walls. In emphysema, the destruction of alveolar wall attachments results in collapse of the bronchioles when a person exhales, causing airflow obstruction that is permanent and irreversible. In chronic bronchitis, the glands lining the larger airways (bronchi) of the lungs enlarge and increase their secretion of mucus. Inflammation of the bronchioles develops and causes smooth muscles in lung tissue to contract (spasm), further obstructing airflow. Inflammation also causes swelling of the airway passages and secretions in them, further limiting airflow. Eventually, the small airways in the lung become narrowed and destroyed. Asthma is also characterized by airflow obstruction. However, unlike airflow obstruction in COPD, airflow obstruction in asthma is completely reversible in most people, either spontaneously or with treatment.
Causes
Cigarette smoking is the most important cause of COPD, although only about 15% of smokers develop the disease. Pipe and cigar smokers develop COPD more often than nonsmokers but not as often as cigarette smokers. It is not clear whether smoking marijuana contributes to COPD. With aging, susceptible cigarette smokers lose lung function more rapidly than nonsmokers. Lung function improves only a little if people stop smoking. However, the rate of decline of lung function returns to that of nonsmokers when people stop smoking, thus delaying development and progression of symptoms.
COPD tends to occur more often in some families, so there may be an inherited tendency.
Working in an environment polluted by chemical fumes or dust or by heavy smoke from indoor cooking fires may increase the risk of COPD (see page Overview of Environmental Lung Diseases). Exposure to air pollution and to smoke from nearby cigarette smokers (secondhand or passive smoke exposure) may cause flare-ups in people who have COPD but probably does not cause COPD.
A rare cause of COPD is a hereditary condition in which the body does not produce enough of the protein alpha1-antitrypsin. The main role of this protein is to prevent neutrophil elastase (an enzyme in certain white blood cells) from damaging the alveoli. Consequently, emphysema develops by early middle age in people with severe alpha1-antitrypsin deficiency (also called alpha1-antiprotease inhibitor deficiency), especially in those who also smoke.
Symptoms
COPD takes years to develop and progress.
In people with COPD, a mild cough that produces clear sputum develops during their 40s or 50s. The cough and sputum production are usually worse when the person first gets out of bed in the morning. Cough and sputum production can persist throughout the day. Shortness of breath may occur during exertion. People often think at first that aging or being in poor physical condition is the cause, and they tend to decrease their physical activity in response. Sometimes, shortness of breath first occurs only when the person has a lung infection (usually bronchitis), during which time the person coughs more and has an increased amount of sputum. The color of the sputum changes from clear or white to yellow or green.
By the time people with COPD reach their middle to late 60s, especially if they continue smoking, shortness of breath during exertion becomes more troublesome. Pneumonia and other lung infections occur more often. Infections may result in severe shortness of breath even when the person is at rest and may require hospitalization. Shortness of breath during activities of daily living, such as toileting, washing, dressing, and sexual activity, may persist after the person has recovered from the lung infection.
About one third of people with severe COPD experience severe weight loss. The cause of weight loss is not clear, and causes may differ among different people. Possible causes include shortness of breath that makes eating difficult and increased levels in the blood of a substance called tumor necrosis factor. Swelling of the legs develops in people who have cor pulmonale. People with COPD may intermittently cough up blood, which is usually due to inflammation of the bronchi, but which always raises the concern of lung cancer. Morning headaches may occur because breathing decreases during sleep, which causes increased retention of carbon dioxide and decreased levels of oxygen in the blood.
As COPD progresses, some people, especially those who have emphysema, develop unusual breathing patterns. Some people breathe out through pursed lips. Others find it more comfortable to stand over a table with their arms outstretched and their weight on their palms or elbows, a maneuver that improves the function of some of the respiratory muscles. Over time, many people develop a barrel chest as the size of the lungs increases because of trapped air. Low oxygen levels in the blood can give a blue tint to the skin (cyanosis). Clubbing of the fingers is rare (see page Clubbing) and raises the suspicion of lung cancer or other lung disorders.
Diagnosis
Chronic bronchitis is diagnosed by the history of a prolonged productive cough. People with chronic obstructive bronchitis have chronic bronchitis, plus evidence of airflow obstruction on pulmonary function tests.
Emphysema is diagnosed on the basis of findings observed during a physical examination and on pulmonary function test results. However, by the time the doctor notices these abnormalities, emphysema is moderately severe. Findings on a chest x-ray or computed tomography (CT) of the chest may also help in diagnosis of emphysema and sometimes chronic bronchitis. It is not important for doctors to differentiate between chronic obstructive bronchitis and emphysema. The most important determinant of how the person feels and functions is the severity of the airflow obstruction.
In mild COPD, doctors may find nothing unusual during the physical examination. As the disease progresses, doctors may hear wheezing or notice a decrease in the normal sounds of breathing (decreased breath sounds) when they listen to the lungs with a stethoscope. Doctors may note that it takes a long time for the person to exhale air that has been inhaled (prolonged expiration). Chest movement diminishes during breathing, and the person may use the neck and shoulder muscles to breathe.
Stopping smoking when the airflow obstruction is mild or moderate often lessens cough, reduces the amount of sputum, and slows the development of shortness of breath. Stopping smoking at any point in the disease process provides some benefit. Trying several strategies at once is most likely to be effective. Among these strategies are committing to a specific date for quitting, using behavioral modification techniques (for example, making cigarettes difficult to obtain or rewarding oneself for abstaining for increasingly long periods of time), group counseling and support sessions, and nicotine replacement (for example, by chewing nicotine gum, wearing a nicotine skin patch, or using a nicotine inhaler, nicotine lozenge, or nicotine nasal spray). The drugs varenicline and bupropion may also help decrease tobacco craving. However, even with the most effective methods, less than half of people who try have quit smoking after one year.
People should also try to avoid exposure to other airborne irritants, including secondhand smoke and air pollution.
Contracting influenza or developing pneumonia may worsen COPD markedly. Therefore, all people with COPD should receive an influenza vaccination every year. Pneumococcal vaccination every 5 or 6 years also probably helps.
Because COPD can cause severe weight loss, people should eat a balanced, nutritious diet.
Bronchial Asthma
The most important characteristic of asthma is narrowing of the airways that can be reversed. The airways of the lungs (the bronchi) are basically tubes with muscular walls. Cells lining the bronchi have microscopic structures, called receptors. These receptors sense the presence of specific substances and stimulate the underlying muscles to contract or relax, thus altering the flow of air. There are many types of receptors, but two main types of receptors are important in asthma:
Beta-adrenergic receptors respond to chemicals such as epinephrine and make the muscles relax, thereby widening (dilating) the airways and increasing airflow.
Cholinergic receptors respond to a chemical called acetylcholine and make the muscles contract, thereby decreasing airflow.
Causes
Affected people usually carry genes that make them susceptible to asthma. Environmental conditions, including conditions before and around the time of birth, can then influence the development of asthma.
Narrowing of the airways is often caused by abnormal sensitivity of cholinergic receptors, which cause the muscles of the airways to contract when they should not. Certain cells in the airways, particularly mast cells, are thought to be responsible for initiating the response. Mast cells throughout the bronchi release substances such as histamine and leukotrienes, which cause smooth muscle to contract, mucus secretion to increase, and certain white blood cells to move to the area. Eosinophils, a type of white blood cell found in the airways of people with asthma, release additional substances, contributing to airway narrowing.
In an asthma attack (sometimes called an exacerbation), the smooth muscles of the bronchi contract, causing the bronchi to narrow (called bronchoconstriction) The tissues lining the airways swell due to inflammation and mucus secretion into the airways. The top layer of the airway lining can become damaged and shed cells, further narrowing the airway. A narrower airway requires the person to exert more effort to breathe. In asthma, the narrowing is reversible, meaning that with appropriate treatment or on their own, the muscular contractions of the airways stop, inflammation resolves so that the airways widen again, and airflow into and out of the lungs returns to normal.
Symptoms
Asthma attacks vary in frequency and severity. Some people who have asthma are symptom-free most of the time, with only an occasional brief, mild episode of shortness of breath. Other people cough and wheeze most of the time and have severe attacks after viral infections, exercise, or exposure to other triggers. Wheezing is a musical sound that occurs when the person breathes out (see page Wheezing). Coughing may be the only symptom in some people (cough-variant asthma). Some people with asthma produce a clear, sometimes sticky (mucoid) phlegm (sputum).
Asthma attacks occur most often in the early morning hours when the effects of protective drugs wear off and the body is least able to prevent airway narrowing.
An asthma attack may begin suddenly with wheezing, coughing, and shortness of breath. At other times, an asthma attack may come on slowly with gradually worsening symptoms. In either case, people with asthma usually first notice shortness of breath, coughing, or chest tightness. The attack may be over in minutes, or it may last for hours or days. Itching on the chest or neck may be an early symptom, especially in children. A dry cough at night or while exercising may be the only symptom.
During an asthma attack, shortness of breath may become severe, creating a feeling of severe anxiety. The person instinctively sits upright and leans forward, using the muscles in the neck and chest to help in breathing, but still struggles for air. Sweating is a common reaction to the effort and anxiety. The heart rate usually quickens, and the person may feel a pounding in the chest.
In a very severe asthma attack, a person is able to say only a few words without stopping to take a breath. Wheezing may diminish, however, because hardly any air is moving in and out of the lungs. Confusion, lethargy, and a blue skin color (cyanosis) are signs that the person’s oxygen supply is severely limited, and emergency treatment is needed.
Treatment
Anti-inflammatory drugs suppress the inflammation that narrows the airways. Anti-inflammatory drugs include corticosteroids (which can be inhaled, taken by mouth, or given intravenously), leukotriene modifiers, and mast cell stabilizers.
Bronchodilators help to relax and widen (dilate) the airways. Bronchodilators include beta-adrenergic drugs (both those for quick relief of symptoms and those for long-term control), anticholinergics, and methylxanthines.
Other types of drugs that directly alter the immune system (called immunomodulators) are sometimes used for people with severe asthma, but most people do not need immunomodulators.
Bronchiectasis
An irreversible widening (dilation) of portions of the breathing tubes or airways (bronchi) resulting from damage to the airway wall.
Bronchiectasis can result when conditions directly injure the bronchial wall or indirectly lead to injury by interfering with normal airway defenses. Airway defenses include tiny projections (cilia) on the cells that line the airways. These cilia beat back and forth, moving the thin liquid layer of mucus that normally coats the airways. Harmful particles and bacteria trapped in this mucus layer are moved up to the throat and coughed out or swallowed.
Whether airway injury is direct or indirect, areas of the bronchial wall are damaged and become chronically inflamed. The inflamed bronchial wall becomes less elastic, resulting in the affected airways becoming widened (dilated) and developing small outpouchings or sacs that resemble tiny balloons. Inflammation also increases secretions (mucus). Because cells with cilia are damaged or destroyed, these secretions accumulate in the widened airways and serve as a breeding ground for bacteria. The bacteria further damage the bronchial wall, leading to a vicious circle of infection and airway damage.
Complications
The inflammation and infection can extend to the small air sacs of the lungs (alveoli) and cause pneumonia, scarring, and a loss of functioning lung tissue. Severe scarring and loss of lung tissue can ultimately strain the right side of the heart as the heart tries to pump blood through the altered lung tissue. The right-sided heart strain can lead to a form of heart failure called cor pulmonale
Causes
The most common cause is severe or repeated respiratory infections. Other causes include
Cystic fibrosis
Other hereditary disorders, such as primary ciliary dyskinesia, in which the ability to clear the airway of organisms that cause infection is impaired
Immunodeficiency disorders
Certain autoimmune disorders, such as rheumatoid arthritis, ulcerative colitis, or Sjögren syndrome
Mechanical factors, such as airway obstruction caused by an inhaled object, chronically enlarged lymph nodes, changes after lung surgery, or a lung tumor
Inhaling toxic substances that injure the airways, such as noxious fumes, gases, smoke (including tobacco smoke), and injurious dust (for example, silica and coal dust)
Symptoms
Bronchiectasis can develop at any age, but the process often begins in early childhood. However, symptoms may not appear until much later. In most people, symptoms begin gradually, usually after a respiratory infection, and tend to worsen over the years. Most people develop a chronic cough that produces thick sputum. The amount and type of sputum depend on the extent of the disease and whether there is a complicating infection (often called a disease flare). Often, people have coughing spells only early in the morning and late in the day. Coughing up of blood (hemoptysis) is common because the damaged airway walls are fragile and have increased numbers of blood vessels. Hemoptysis may be the first or only symptom.
Recurrent fever or chest pain, with or without frequent bouts of pneumonia, may also occur. People with widespread bronchiectasis may develop wheezing or shortness of breath. People whose bronchiectasis progresses to cor pulmonale or respiratory failure also have fatigue, lethargy, and worsening shortness of breath, particularly during exertion. If bronchiectasis is severe and chronic, people commonly lose lean body mass.
Treatment and Prognosis
Treatment of bronchiectasis is directed toward eradicating infections when possible, preventing certain infections with vaccines, decreasing the build-up of mucus, decreasing inflammation, and relieving airway obstruction. Drugs that suppress coughing may worsen the condition and generally should not be used. Early, effective treatment can reduce complications such as hemoptysis, low oxygen levels in the blood, respiratory failure, and cor pulmonale.
Pulmonary Thromboembolism
The pulmonary arteries carry blood from the heart to the lungs. The blood picks up oxygen from the lungs and travels back to the heart. From the heart, the blood is pumped to the rest of the body to provide oxygen to the tissues. When a pulmonary artery is blocked by an embolus, people may not be able to get sufficient oxygen into the blood. Large emboli may cause so much blockage that the heart has to strain to pump blood through the pulmonary arteries that remain open (massive pulmonary embolism). If too little blood is pumped or the heart is strained excessively, the person can go into shock and die. Sometimes, the blockage of blood flow causes lung tissue to die (a condition called pulmonary infarction ).
The body usually breaks up small clots more quickly than larger clots, keeping damage to a minimum. Large clots take much longer to disintegrate, so more damage may be done.
Causes
The most common type of pulmonary embolism is a blood clot
Usually the blood clot forms in a leg or pelvic vein when blood flow slows down or stops, as may occur in the leg veins when a person stays in one position for a long time after an injury (for example, a hip fracture) or major surgery. Other causes include conditions that make the blood clot more easily or the presence of a foreign substance within the bloodstream (for example, an intravenous catheter).
Small emboli may not cause any symptoms, but when symptoms do occur, they often develop abruptly.
Symptoms of pulmonary embolism may include
Shortness of breath
Chest pain
Light-headedness or fainting
Shortness of breath may be the only symptom, especially if pulmonary infarction does not develop. Often, the breathing is very rapid, and the person may feel anxious or restless and appear to have an anxiety attack.
Some people have pain in the chest. The heartbeat may become rapid, irregular, or both.
In some people, particularly those with very large emboli, the first pulmonary embolism symptoms are light-headedness or loss of consciousness. If people suddenly lose consciousness, their body may shake, appearing to be seizures. Blood pressure may drop dangerously low (a condition called shock), the skin may be cool and have a blue color (cyanosis), and the person could suddenly die.
In older people, the first symptom of pulmonary embolism may be confusion or deterioration of mental function. These symptoms usually result from a sudden decrease in the heart’s ability to deliver enough oxygen-rich blood to the brain and other organs.
Pulmonary infarction
Pulmonary infarction is when some of the lung tissue dies due to blockage of a lung blood vessel by a pulmonary embolus. Usually the embolus causing pulmonary infarction is small. The symptoms of pulmonary infarction develop over hours. If pulmonary infarction occurs, the person experiences coughing that may produce blood-stained sputum, sharp chest pain when breathing in, and in some cases fever. Symptoms of infarction often last several days but usually become milder every day.
Tests that suggest pulmonary embolism
A chest x-ray may reveal subtle changes in the blood vessel patterns that occur after embolism and may reveal signs of pulmonary infarction. However, the x‑ray results are often normal, and even when they are abnormal, they rarely enable doctors to establish the diagnosis with certainty.
Electrocardiography (ECG) may show abnormalities. These abnormalities can support or suggest the diagnosis of pulmonary embolism but cannot confirm it.
The level of oxygen in the blood is measured with a sensor that is attached to a fingertip (oximetry). Because pulmonary embolism blocks pulmonary arteries, the level of oxygen in the blood may be low.
Treatment Heparin Wafarin Supportive therapy IVC filter
Pneumonia
Community Acquired
Is lung infection that develops in people with limited or no contact with medical institutions or settings.
Causes Streptococcus pneumoniae ( pneumococcus) causes about 500,000 cases of pneumonia in the United States each year. There are over 90 types of pneumococci, but most serious disease is caused by only a small number of types. Pneumococcal pneumonia can be very severe, particularly in young children and the elderly.
Haemophilus influenzae pneumonia may occur in adults but is more common in children. However, childhood infection has become much less common since children have been routinely vaccinated against H. influenzae.
Chlamydophila pneumoniae is the second most common cause of lung infections in healthy people aged 5 to 35 years. C. pneumoniae is commonly responsible for outbreaks of respiratory infection within families, in college dormitories, and in military training camps. It causes a pneumonia that is rarely severe and infrequently requires hospitalization. Chlamydia psittaci pneumonia (psittacosis) is a rare infection caused by a different strain of chlamydia and occurs in people who own or are often exposed to birds.
Mycoplasma pneumoniae causes infection very similar to that caused by C. pneumoniae. Mycoplasma pneumoniae is more common in older children and adults younger than 40, especially those living in crowded environments, such as schools, college dormitories, and military barracks. Although the illness is rarely severe, symptoms can last for weeks or even months.
Legionella pneumophila (see Legionella infection) causes pneumonia and flu-like symptoms sometimes called Legionnaires’ disease. It accounts for about 1 to 8% of all pneumonias and about 4% of fatal pneumonias acquired in hospitals. Legionella bacteria live in water, and outbreaks have occurred primarily in hotels and hospitals when the organism has spread through the air conditioning systems or water supplies, such as showers. No cases have been identified in which one person directly infected another.
“Walking pneumonia” is a nonmedical term used to describe a mild case of community-acquired pneumonia that does not require bedrest or hospitalization. Some people even feel well enough to go to work and participate in other daily activities. The cause is often a viral lung infection or a bacterial infection with Mycoplasma pneumoniae or Chlamydophila pneumoniae.
Common viral causes include: Respiratory syncytial virus (RSV) Adenoviruses Influenza viruses Metapneumovirus Parainfluenza viruses The virus that causes chickenpox can also cause a lung infection. Hantavirus and severe acute respiratory syndrome (SARS) are also viral causes of pneumonia. Sometimes a bacterial pneumonia can occur after a lung infection caused by a virus.
Fungal causes of pneumonia
Common fungal causes of pneumonia include
Histoplasma capsulatum ( histoplasmosis)
Coccidioides immitis ( coccidioidomycosis)
Less common fungi include Blastomyces dermatitidis ( blastomycosis) and Paracoccidioides braziliensis ( paracoccidioidomycosis). Pneumocystis jirovecii commonly causes pneumonia in people who have HIV infection or are immunocompromised.
Parasites that cause pneumonia Parasites that cause pneumonia in people who live in developed countries include Toxocara canis (visceral larva migrans) T. catis (visceral larva migrans) Dirofilaria immitis (dirofilariasis) Paragonimus westermani (paragonimiasis)
Symptoms A general feeling of weakness (malaise) Cough Shortness of breath Fever Chills Chest pain Cough typically produces sputum (thick or discolored mucus) in older children and adults, but the cough is dry in infants, young children, and older people. Shortness of breath usually is mild and occurs mainly during activity. Chest pain is typically worse when breathing in or coughing. Sometimes people have upper abdominal pain
Treatment depends on causative pathogen
Pneumonia
Hospital Acquired
Hospital-acquired pneumonia develops in people who have been hospitalized, typically after about 2 days or more of hospitalization. Health care–associated pneumonia develops in people who reside in nursing homes or who have contact with medical settings, such as dialysis centers.
Pneumonia acquired in the hospital or in another health care setting is usually more severe than pneumonia acquired in the community because the infecting organisms tend to be more aggressive. They are also less likely to respond to antibiotics (called resistance) and are, therefore, harder to treat. Additionally, people in hospitals and nursing homes and those who have contact with medical settings tend to be sicker even without pneumonia than those living in the community and therefore are not as able to fight the infection.
Causes
People who are hospitalized and seriously ill, especially if they require assistance in breathing from a breathing machine (mechanical ventilator), are at greatest risk of acquiring pneumonia. Other risk factors include
Previous antibiotic treatment
Coexisting illness such as heart, lung, liver, or kidney dysfunction
Age older than 70
Recent abdominal or chest surgery
Possibly the use of proton pump inhibitors (omeprazole, esomeprazole, lansoprazole, or pantoprazole) for treatment of gastroesophageal reflux disease
Debilitation, particularly among nursing home residents
Organisms that do not normally cause pneumonia in healthy people can cause pneumonia in people who are hospitalized or debilitated. Many such people have an immune system that is not able to resist even mild infectious challenges. The most likely organisms depend on what organisms are prevalent in the hospital and sometimes depend on what other illnesses the person has.
Symptoms
Symptoms are generally the same as those for community-acquired pneumonia
Treatment is with antibiotics that are chosen based on which organisms are most likely to be the cause and the specific risk factors the person has. Because of the seriousness of the infection, people who developed pneumonia while in a nursing home are often treated in the hospital. People who are seriously ill may be placed in an intensive care unit and sometimes put on a ventilator. Treatments include intravenous antibiotics, oxygen, and intravenous fluids.
Suppurative Pneumonia
any pneumonia associated with the formation of pus and destruction of pulmonary tissue; abscess formation may occur.
Suppurative pneumonia is the term used to describe a form of pneumonic consolidation in which there is destruction of the lung parenchyma by the inflammatory process. Although microabscess formation is a characteristic histological feature of suppurative pneumonia, it is usual to restrict the term ‘pulmonary abscess’ to lesions in which there is a fairly large localized collection of pus, or a cavity lined by chronic inflammatory tissue, from which pus has escaped by rupture into a bronchus.
Suppurative pneumonia and pulmonary abscess may be produced by infection of previously healthy lung tissue with Staph. aureus or Klebsiella pneumoniae. These are, in effect, primary bacterial pneumonias associated with pulmonary suppuration. More frequently, suppurative pneumonia and pulmonary abscess develop after the inhalation of septic material during operations on the nose, mouth or throat under general anaesthesia, or of vomitus during anaesthesia or coma. In such circumstances gross oral sepsis may be a predisposing factor. Additional risk factors for aspiration pneumonia include bulbar or vocal cord palsy, achalasia or esophageal reflux and alcoholism.
Lung Abscess
A lung abscess is usually caused by bacteria that normally live in the mouth or throat and that are inhaled (aspirated) into the lungs, resulting in an infection. Often, gum (periodontal) disease is the source of the bacteria that cause a lung abscess. The body has many defenses (such as a cough) to help prevent bacteria from getting into the lungs. Infection occurs primarily when a person is unconscious or very drowsy because of sedation, anesthesia, alcohol or drug use, or a disease of the nervous system and is thus less able to cough to clear the aspirated bacteria. In people whose immune system functions poorly, a lung abscess may be caused by organisms that are not typically found in the mouth or throat, such as fungi or Mycobacterium tuberculosis (the organism that causes tuberculosis). Other bacteria that can cause lung abscesses are streptococci and staphylococci, including methicillin-resistant Staphylococcus aureus (MRSA), which is a serious infection.
Obstruction of the airways also can lead to abscess formation. If the branches of the windpipe (bronchi) are blocked by a tumor or a foreign object, an abscess can form because secretions (mucus) can accumulate behind the obstruction. Bacteria sometimes enter these secretions. The obstruction prevents the bacteria-laden secretions from being coughed back up through the airway.
Less commonly, abscesses result when bacteria or infected blood clots travel through the bloodstream to the lung from another infected site in the body (septic pulmonary emboli).
Primary Tumours of the Lung
Cancer that originates from lung cells is called a primary lung cancer. Primary lung cancer can start in the airways that branch off the trachea to supply the lungs (the bronchi) or in the small air sacs of the lung (the alveoli). Cancer may also spread (metastasize) to the lung from other parts of the body (most commonly from the breasts, colon, prostate, kidneys, thyroid gland, stomach, cervix, rectum, testes, bones, or skin).
There are two main categories of primary lung cancer:
Non–small cell lung carcinoma: About 85 to 87% of lung cancers are in this category. This cancer grows more slowly than small cell lung carcinoma. Nevertheless, by the time about 40% of people are diagnosed, the cancer has spread to other parts of the body outside of the chest. The most common types of non–small cell lung carcinoma are squamous cell carcinoma, adenocarcinoma, and large cell carcinoma.
Small cell lung carcinoma: Sometimes called oat cell carcinoma, this cancer accounts for about 13 to 15% of all lung cancers. It is very aggressive and spreads quickly. By the time that most people are diagnosed, the cancer has metastasized to other parts of the body.
Causes
Cigarette smoking is the leading cause of cancer, accounting for about 85% of all lung cancer cases. About 10% of all smokers (former or current) eventually develop lung cancer, and both the number of cigarettes smoked and number of years of smoking seem to correlate with the increased risk. In people who quit smoking, the risk of developing lung cancer decreases, but former smokers will still always have a higher risk of developing lung cancer than people who never smoked.
About 15 to 20% of people who develop lung cancer have never smoked or have smoked only minimally. In these people, the reason why they develop lung cancer is unknown, but certain genetic mutations may be responsible. Other possible risk factors include air pollution, exposure to cigar smoke and secondhand cigarette smoke and exposure to carcinogens such as asbestos, radiation, radon, arsenic, chromates, nickel, chloromethyl ethers, polycyclic aromatic hydrocarbons, mustard gas, or coke-oven emissions, encountered or breathed in at work, and exclusively using open fires for cooking and heating. The risk of contracting lung cancer is greater in people who are exposed to these substances and who also smoke cigarettes.
In rare incidences, lung cancers, especially adenocarcinoma and bronchioloalveolar cell carcinoma (a type of adenocarcinoma), develop in people whose lungs have been scarred by other lung disorders, such as tuberculosis.
Also, smokers who take beta-carotene supplements may have an increased risk of developing lung cancer.
Diagnosis
Doctors explore the possibility of lung cancer when a person, especially a smoker, has a persistent or worsening cough or other lung symptoms (such as shortness of breath or coughed-up sputum tinged with blood), or weight loss. Usually, the first test is a chest x-ray, which can detect most lung tumors, although it may miss small ones. Sometimes a shadow detected on a chest x-ray done for other reasons (such as before surgery) provides doctors with the first clue, although such a shadow is not proof of cancer.
Computed tomography (CT) may be done next. CT can show characteristic patterns that help doctors make the diagnosis. They also can show small tumors that are not visible on chest x-rays and reveal whether the lymph nodes inside the chest are enlarged.
Prevention and Treatment
Prevention of lung cancer includes quitting smoking ( Smoking) and avoiding exposure to potentially cancer-causing substances.
Doctors use various treatments for both small cell and non–small cell lung cancer. Surgery, chemotherapy, and radiation therapy can be used individually or in combination. The precise combination of treatments depends on the type, location, and severity of the cancer, whether the cancer has spread, and the person’s overall health. For example, in some people with advanced non–small cell lung cancer, treatment includes chemotherapy and radiation therapy before, after, or instead of surgical removal. Some people with non–small cell lung cancer survive significantly longer when treated with chemotherapy, radiation therapy, or some of the newer targeted therapies. Targeted therapies include drugs, such as biologic agents that specifically target lung tumors.
Surgery is the treatment of choice
Pleurisy. Pleural Effusion
Pleurisy is inflammation of the pleurae which impairs their lubricating function and causes pain when brathing. Caused by pneumonia and other diseases of the chest or abdomen.
Pleural effusion is the abnormal accumulation of fluid in the pleural space (the area between the two layers of the thin membrane that covers the lungs.
Types of fluid
Depending on the cause, the fluid may be either
Rich in protein (exudate)
Watery (transudate)
Doctors use this distinction to help determine the cause. For example, heart failure and cirrhosis are common causes of watery fluid in the pleural space. Pneumonia, cancer, and viral infections are common causes of pleural effusion with an exudative fluid.
Blood in the pleural space (hemothorax) usually results from a chest injury. Rarely, a blood vessel ruptures into the pleural space when no injury has occurred, or a bulging area in the aorta (aortic aneurysm) leaks blood into the pleural space.
Pus in the pleural space (empyema) can accumulate when pneumonia or a lung abscess spreads into the space. Empyema may also complicate an infection due to chest wounds, chest surgery, rupture of the esophagus, or an abscess in the abdomen.
Lymphatic (milky) fluid in the pleural space (chylothorax) is caused by an injury to the main lymphatic duct in the chest (thoracic duct) or by a blockage of the duct by a tumor.
Urine in the pleural space (urinothorax) is uncommon and can accumulate if the tubes that drain urine from the kidneys (ureters) are blocked.
Fluid in the pleural space that contains excessive amounts of cholesterol results from a long-standing pleural effusion caused by a condition such as tuberculosis or rheumatoid arthritis.
Symptoms
Many people with pleural effusion have no symptoms at all. The most common symptoms, regardless of the type of fluid in the pleural space or its cause, are shortness of breath and chest pain. Chest pain is usually of a type called pleuritic pain (the term pleurisy is no longer or only rarely used). It may be felt only when the person breathes deeply or coughs, or it may be felt continuously but may be worsened by deep breathing and coughing. The pain is usually felt in the chest wall right over the site of the inflammation. However, the pain may be felt also or only in the upper abdominal region or neck and shoulder as referred pain
Diagnosis
Chest x-ray
Sometimes laboratory tests done on a sample of the fluid
Computed tomography (CT) angiography
Treatment
Treatment of the disorder causing pleural effusion
Drainage of large pleural effusions
Small pleural effusions may not require treatment, although the underlying disorder must be treated. Sometimes the person is given analgesics until the fluid is drained or drains away on its own.
Larger pleural effusions, especially those that cause shortness of breath, may require drainage. Usually, drainage dramatically relieves shortness of breath. Often, fluid can be drained using thoracentesis. An area of skin between two lower ribs is anesthetized, then a small needle is inserted and gently pushed deeper until it reaches the fluid. A thin plastic catheter is often guided over the needle into the fluid to lessen the chance of puncturing the lung and causing a pneumothorax. Although thoracentesis is usually done for diagnostic purposes, doctors can safely remove as much as about 1½ quarts (1.5 liters) of fluid at a time using this procedure.
Spontaneous Pneumothorax
Normally, the pressure in the pleural space is lower than that inside the lungs or outside the chest. If a perforation develops that causes a connection between the pleural space and the inside of the lungs or outside the chest, air enters the pleural space until the pressures become equal or the connection closes. When there is air in the pleural space, the lung partially collapses. Sometimes most or all of the lung collapses, leading to severe shortness of breath.
Primary spontaneous pneumothorax is a pneumothorax that occurs without any apparent cause in people without a known lung disorder. Primary spontaneous pneumothorax usually occurs when a small weakened area of lung (bulla) ruptures. The condition is most common in tall men younger than age 40 who smoke. Most people recover fully. However, primary spontaneous pneumothorax recurs in up to 50% of people.
Secondary spontaneous pneumothorax occurs in people with an underlying lung disorder. This type of pneumothorax most often occurs when a bulla ruptures in an older person who has chronic obstructive pulmonary disease (COPD), but it also occurs in people with other lung conditions, such as cystic fibrosis, asthma, Langerhans cell histiocytosis, sarcoidosis, lung abscess, tuberculosis, and Pneumocystis pneumonia. Because of the underlying lung disorder, the symptoms and outcome are generally worse in secondary spontaneous pneumothorax. The recurrence rate is similar to that of primary spontaneous pneumothorax.
Catamenial pneumothorax is a rare form of secondary spontaneous pneumothorax. It occurs within 48 hours of the onset of menstruation in premenopausal women and sometimes in postmenopausal women taking estrogen. Tissue from the lining of the uterus (endometrium) moves to the lungs through an opening in the diaphragm or through the veins (called endometriosis—see page Endometriosis).
A pneumothorax may also occur after an injury or a medical procedure that introduces air into the pleural space, such as thoracentesis, bronchoscopy, or thoracoscopy
Symptoms
Symptoms vary greatly depending on how much air enters the pleural space, how much of the lung collapses, and the person’s lung function before the pneumothorax occurred. They range from none to a little shortness of breath or chest pain to severe shortness of breath, shock, and life-threatening cardiac arrest.
Most often, sharp chest pain and shortness of breath and occasionally a dry hacking cough begin suddenly. Pain may also be felt in the shoulder, neck, or abdomen. Symptoms tend to be less severe in a slowly developing pneumothorax than in a rapidly developing one.
Treatment
Air removal
A small, primary spontaneous pneumothorax usually requires no treatment. It usually does not cause serious breathing problems, and the air is absorbed in several days. People may be given oxygen though the nose or a face mask to help speed the absorption of air. The full absorption of air in a larger pneumothorax may take 2 to 4 weeks. However, the air can be removed more quickly by inserting a catheter or chest tube into the pneumothorax.
If a primary spontaneous pneumothorax is large enough to make breathing difficult, the air can be removed (aspirated) with a large syringe attached to a plastic catheter inserted into the chest. The catheter can be removed or sealed and then left in place for a time so that any air that reaccumulates can be removed.
A chest tube is used to drain the air if catheter aspiration is unsuccessful and when any other type of pneumothorax (such as a secondary spontaneous pneumothorax or a traumatic pneumothorax) occurs. The chest tube is inserted through an incision in the chest wall and is connected to a water-sealed drainage system or a one-way valve that allows the air to exit without allowing any air to get back in. A suction pump may be attached to the chest tube if air keeps leaking in from an abnormal connection (fistula) between an airway and the pleural space.
