Idiopathic pulmonary fibrosis (IPF) is a condition in which the lungs become scarred and breathing becomes increasingly difficult.
The most common signs and symptoms of idiopathic pulmonary fibrosis are shortness of breath and a persistent dry, hacking cough. Many affected individuals also experience a loss of appetite and gradual weight loss.

The clinical findings of IPF are bibasilar reticular abnormalities, ground glass opacities, or diffuse nodular lesions on high-resolution computed tomography and abnormal pulmonary function studies that include evidence of restriction (reduced VC with an increase in FEV1/FVC ratio) and/or impaired gas exchange (increased P(A-a)O2 with rest or exercise or decreased diffusion capacity of the lung for carbon monoxide [DLCO]).

Cystic fibrosis (CF) is a multisystemic, autosomal recessive disorder that predominantly affects infants, children, and young adults. CF is the most common life-limiting genetic disorder in whites, with an incidence of 1 case per 3200-3300 new-borns in the United States.

People with CF can have a variety of symptoms, including:
Very salty-tasting skin
Persistent coughing, at times with phlegm
Frequent lung infections including pneumonia or bronchitis
Wheezing or shortness of breath
Poor growth or weight gain in spite of a good appetite
Frequent greasy, bulky stools or difficulty with bowel movements
Male infertility

Signs of bronchiectasis include the tubular shadows; tram tracks, or horizontally oriented bronchi; and the signet-ring sign, which is a vertically oriented bronchus with a luminal airway diameter that is 1.5 times the diameter of the adjacent pulmonary arterial branch.

Bronchiectasis is characterized by parallel, thick, line markings radiating from hila (line tracks) in cylindrical bronchiectasis. Ring shadows represent dilated thick-wall bronchi seen in longitudinal section or on-end or dilated bronchi in varicose bronchiectasis.

Pseudomonas aeruginosa is the key bacterial agent of cystic fibrosis (CF) lung infections, and the most important pathogen in progressive and severe CF lung disease. This opportunistic pathogen can grow and proliferate in patients, and exposure can occur in hospitals and other healthcare settings.

Haemophilus influenzae is regularly involved in chronic lung infections and acute exacerbations of CF patients

In asthma, a reversible increase in residual volume (RV), functional residual capacity (FRC), and total lung capacity (TLC) may occur. There is a fall in FEV1, FVC and gas transfer.

Squamous-cell carcinoma is the most common histological type of lung cancer to cavitate (82% of cavitary primary lung cancer), followed by adenocarcinoma and large cell carcinoma. Multiple cavitary lesions in primary lung cancer are rare, however, multifocal bronchoalveolar cell carcinoma can occasionally have multiple cavitary lesions. Small cell carcinoma is not known to cavitate.

In adult practice, biochemical analysis of pleural fluid plays an important part in the management of pleural effusions. Protein levels or Light’s criteria differentiate exudates from transudates, while infection is indicated by pleural acidosis associated with raised LDH and low glucose levels. In terms of treatment, the pH may even guide the need for tube drainage, suggested by pH <7.2 in an infected effusion, although the absolute protein values are of no value in determining the likelihood of spontaneous resolution or chest drain requirements. pH is therefore the most important factor.

Serial Peak Expiratory Flow measurement at work and home is a feasible, sensitive, and specific test for the diagnosis of occupational asthma. For a diagnosis of occupational asthma, it is important to establish a relationship objectively between the workplace exposure and asthma symptoms and signs. Physiologically, this can be achieved by monitoring airflow limitation in relation to occupational exposure(s). If there is an effect of a specific workplace exposure, airflow limitation should be more prominent on work days compared with days away from work (or days away from the causative agent). Airflow limitation can be measured by spirometry, with peak expiratory flow (PEF) and/or forced expiratory volume in 1 s(FEV1) being the most useful for observing changes in airway calibre. Other tests mentioned are less reliable and would not help in establishing a satisfactory diagnosis of occupational asthma.

In any patient with asthma, a decreasing PaO2 and an increasing PaCO2, even into the normal range, indicates severe airway obstruction that is leading to respiratory muscle fatigue and patient exhaustion.

Chest tightness and cough, which are the most common symptoms of asthma, are probably the result of inflammation, mucus plugs, oedema, or smooth muscle constriction in the small peripheral airways. Because major obstruction of the peripheral airways can occur without recognizable increases of airway resistance or FEV1, the physiologic alterations in acute exacerbations are generally subtle in the early stages. Poorly ventilated alveoli subtending obstructed bronchioles continue to be perfused, and as a consequence, the P(A-a)O2 increases and the PaO2 decreases. At this stage, ventilation is generally increased, with excessive elimination of carbon dioxide and respiratory alkalemia.

Allergic bronchopulmonary aspergillosis (ABPA) is a form of lung disease that occurs in some people who are allergic to Aspergillus. With ABPA, this allergic reaction causes the immune system to overreact to Aspergillus leading to lung inflammation. ABPA causes bronchospasm (tightening of airway muscles) and mucus build-up resulting in coughing, breathing difficulty and airway obstruction.

Treatment of ABPA aims to control inflammation and prevent further injury to your lungs. ABPA is a hypersensitivity reaction that requires treatment with oral corticosteroids. Inhaled steroids are not effective. ABPA is usually treated with a combination of oral corticosteroids and anti-fungal medications. The corticosteroid is used to treat inflammation and blocks the allergic reaction. Examples
of corticosteroids include: prednisone, prednisolone or methylprednisolone. Inhaled corticosteroids alone – such as used for asthma treatment – are not effective in treating ABPA. Usually treatment with an oral corticosteroid is needed for months.

The second type of therapy used is an anti-fungal medication, like itraconazole and voriconazole. These medicines help kill Aspergillus so that it no longer colonizes the airway. Usually one of these drugs is given for at least 3 to 6 months. However, even this treatment is not curative and can have side effects.

If a pleural effusion is present, a diagnostic thoracentesis may be performed and analysed for pH, lactate dehydrogenase, glucose levels, specific gravity, and cell count with differential. Pleural fluid may also be sent for Gram stain, culture, and sensitivity. Acid-fast bacillus testing may also be considered and the fluid may be sent for cytology if cancer is suspected.

The following findings are suggestive of an empyema or parapneumonic effusion that will likely need a chest tube or pigtail catheter for complete resolution:
-Grossly purulent pleural fluid
-pH level less than 7.2
-WBC count greater than 50,000 cells/µL (or polymorphonuclear leukocyte count of 1,000 IU/dL)
-Glucose level less than 60 mg/dL
-Lactate dehydrogenase level greater than 1,000 IU/mL
-Positive pleural fluid culture

The most often used golden criteria for empyema are pleural effusion with macroscopic presence of pus, a positive Gram stain or culture of pleural fluid, or a pleural fluid pH under 7.2 with normal peripheral blood ph.

Pulmonary mycobacterium avium complex (MAC) infection in immunocompetent hosts generally manifests as cough, sputum production, weight loss, fever, lethargy, and night sweats. The onset of symptoms is insidious.
In patients who may have pulmonary infection with MAC, diagnostic testing includes acid-fast bacillus (AFB) staining and culture of sputum specimens.

The ATS/IDSA guidelines include clinical, radiographic, and bacteriologic criteria to establish a diagnosis of nontuberculous mycobacterial lung disease.

Clinical criteria are as follows:

Pulmonary signs and symptoms such as cough, fatigue, weight loss; less commonly, fever and weight loss; dyspnoea

Appropriate exclusion of other diseases (e.g., carcinoma, tuberculosis).

At least 3 sputum specimens, preferably early-morning samples taken on different days, should be collected for AFB staining and culture. Sputum AFB stains are positive for MAC in most patients with pulmonary MAC infection. Mycobacterial cultures grow MAC in about 1-2 weeks, depending on the culture technique and bacterial burden.

Long-term oxygen therapy (LTOT) ≥ 15 h/day improves survival in hypoxemic chronic obstructive pulmonary disease (COPD). It significantly helps in reducing pulmonary hypertension associated with COPD and treating underlying pathology of future heart failure. There is little to no benefit of oxygen therapy for less than 15 hours.

The right and left lung anatomy are similar but asymmetrical. The right lung consists of three lobes: right upper lobe (RUL), right middle lobe (RML), and right lower lobe (RLL). The left lung consists of two lobes: right upper lobe (RUL) and right lower lobe (RLL). The right lobe is divided by an oblique and horizontal fissure, where the horizontal fissure divides the upper and middle lobe, and the oblique fissure divides the middle and lower lobes. In the left lobe there is only an oblique fissure that separates the upper and lower lobe.

The lobes further divide into segments which are associated with specific segmental bronchi. Segmental bronchi are the third-order branches off the second-order branches (lobar bronchi) that come off the main bronchus.

The right lung consists of ten segments. There are three segments in the RUL (apical, anterior and posterior), two in the RML (medial and lateral), and five in the RLL (superior, medial, anterior, lateral, and posterior). The oblique fissure separates the RUL from the RML, and the horizontal fissure separates the RLL from the RML and RUL.

There are eight to nine segments on the left depending on the division of the lobe. In general, there are four segments in the left upper lobe (anterior, apicoposterior, inferior and superior lingula) and four or five in the left lower lobe (lateral, anteromedial, superior and posterior). The medium sized airways offer the maximum airway resistance, not smaller ones.

The following drugs should be used as normal during pregnancy:
short acting β2 -agonists
long acting β2- agonists
inhaled corticosteroids
oral and intravenous theophyllines

Use steroid tablets as normal when indicated during pregnancy for severe asthma. Steroid tablets should never be withheld because of pregnancy.
If leukotriene receptor antagonists are required to achieve adequate control of asthma then they should not be withheld during pregnancy.

Postmenopausal oestrogen therapy and hormone therapy are associated with an increased risk of thromboembolism. The relative risk seems to be even greater if the treated population has pre-existing risk factors for thromboembolism, such as obesity, immobilization, and fracture. Cor pulmonale can occur secondary to small recurrent pulmonary embolisms. Pneumonias and bronchiectasis usually present with purulent sputum, and in case of carcinoma there may be other associated symptoms like weight loss, etc.

Nice guidelines for lung reduction surgery:

FEV1 > 20% predicted
PaCO2 < 7.3 kPa
TLco > 20% predicted
Upper lobe predominant emphysema

This patient has pCO2 of 7.4 so she is unsuitable for referral for lung reduction surgery.

Small cell lung cancer (SCLC) is characterized by rapid growth and early dissemination. Prompt initiation of treatment is important.

Patients with clinical stage Ia (T1N0) after standard staging evaluation may be considered for surgical resection, but combined treatment with chemotherapy and radiation therapy is the standard of care. Radiation therapy is often added at the second cycle of chemotherapy.

Historically, patients undergoing surgery for small cell lung cancer (SCLC) had a dismal prognosis. However, more recent data suggest that patients with true stage I SCLC may benefit from surgical resection.

Common sites of hematogenous metastases include the brain, bones, liver, adrenal glands, and bone marrow. The symptoms depend upon the site of spread.

Pneumonia is the predominant clinical manifestation of Legionnaires disease (LD). After an incubation period of 2-10 days, patients typically develop the following nonspecific symptoms:
Fever
Weakness
Fatigue
Malaise
Myalgia
Chills

Respiratory symptoms may not be present initially but develop as the disease progresses. Almost all patients develop a cough, which is initially dry and non-productive, but may become productive, with purulent sputum and, (in rare cases) haemoptysis. Patients may experience chest pain.
Common GI symptoms include diarrhoea (watery and non bloody), nausea, vomiting, and abdominal pain.

Fever is typically present (98%). Temperatures exceeding 40°C occur in 20-60% of patients. Lung examination reveals rales and signs of consolidation late in the disease course.

Males are more than twice as likely as females to develop Legionnaires disease.

Age
Middle-aged and older adults have a high risk of developing Legionnaires disease while it is rare in young adults and children. Among children, more than one third of reported cases have occurred in infants younger than 1 year.

Situations suggesting Legionella disease:
-Gram stains of respiratory samples revealing many polymorphonuclear leukocytes with few or no organisms

-Hyponatremia

-Pneumonia with prominent extrapulmonary manifestations (e.g., diarrhoea, confusion, other neurologic symptoms)

Specific therapy includes antibiotics capable of achieving high intracellular concentrations (e.g., macrolides, quinolones, ketolides, tetracyclines, rifampicin).
Clarithromycin, a new macrolide antibiotic, is at least four times more active in vitro than erythromycin against Legionella pneumophila. In this study the safety and efficacy of orally administered clarithromycin (500 to 1,000 mg bid) in the treatment of Legionella pneumonia were evaluated.
Clarithromycin is a safe effective treatment for patients with severe chest infections due to Legionella pneumophila.

Chronic obstructive pulmonary disease (COPD) is a complex and progressive chronic lung disease. Typically, COPD includes emphysema and chronic bronchitis. COPD is characterized by the restriction of airflow into and out of the lungs. The obstruction of airflow makes breathing difficult. The causes of COPD include smoking, long-term exposure to air pollutants and a rare genetic disorder.

The Global Initiative for Chronic Obstructive Lung Disease (GOLD) developed the GOLD Staging System. In the GOLD System, the forced expiratory volume in one second (FEV1) measurement from a pulmonary function test is used to place COPD into stages. Often, doctors also consider your COPD symptoms.

COPD has four stages. The stages of COPD range from mild to very severe. COPD affects everyone differently. Because COPD is a progressive lung disease, it will worsen over time.
The Stages of COPD:
Mild COPD or Stage 1—Mild COPD with a FEV1 about 80 percent or more of normal.
Moderate COPD or Stage 2—Moderate COPD with a FEV1 between 50 and 80 percent of normal.
Severe COPD or Stage 3—Severe emphysema with a FEV1 between 30 and 50 percent of normal.
Very Severe COPD or Stage 4—Very severe or End-Stage COPD with a lower FEV1 than Stage 3, or people with low blood oxygen levels and a Stage 3 FEV1.

This patient has a FEV1 percent of 63 which falls within the stage 2 or moderate COPD.

A single dose of intravenous magnesium sulphate is safe and may improve lung function and reduce intubation rates in patients with acute severe asthma. Intravenous magnesium sulphate may also reduce hospital admissions in adults with acute asthma who have had little or no response to standard treatment.

Consider giving a single dose of intravenous magnesium sulphate to patients with acute severe asthma (PEF <50% best or predicted) who have not had a good initial response to inhaled bronchodilator therapy. Magnesium sulphate (1.2–2 g IV infusion over 20 minutes) should only be used following consultation with senior medical staff.

Smoking cessation is the most effective intervention in stopping the progression of COPD, as well as increasing survival and reducing morbidity. This is why smoking cessation should be the top priority in the treatment of COPD. Long term oxygen therapy (LTOT) may increase survival in hypoxic patients. The rest of the options dilate airways, reduce inflammation and thereby improve symptoms but do not necessarily increase survival.

Historically, high rates of maternal and fetal death have been reported for pregnant women with pulmonary hypertension (30–56% and 11–28%, respectively). The causes of poor maternal outcomes are varied and include risk of death from right heart failure and stroke from intracardiac shunting. Furthermore, there is a high peri-/post-partum risk due to haemodynamic stress, bleeding complications and the use of general anaesthesia, which can all lead to right heart failure.
The most common risk to the foetus is death, with premature birth and growth retardation being reported in successfully delivered children.
CXR is not contraindicated in pregnancy. D-dimers are not used as a diagnostic aid as they are almost always elevated in pregnancy. Nifedipine, although contraindicated in pregnant women may be used judiciously if the need arises.

Pneumothorax is defined as air in the pleural space and may be classified as spontaneous, traumatic or iatrogenic. Primary spontaneous pneumothorax occurs in patients without clinically apparent lung disease.
Primary pneumothorax has an incidence of 18-28 per 100,000 per year for men and 1.2-6 per 100,000 per year for women. Most patients present with ipsilateral pleuritic chest pain and acute shortness of breath. Shortness of breath is largely dependent on the size of the pneumothorax and whether there is underlying chronic lung disease.

Young patients may have chest pain only. Most episodes of pneumothorax occur at rest. Symptoms may resolve within 24 hours in patients with primary spontaneous pneumothorax. The diagnosis of a pneumothorax is confirmed by finding a visceral pleural line displaced from the chest wall, without distal lung markings, on a posterior-anterior chest radiograph.

Breathless patients should not be left without intervention regardless of the size of pneumothorax. If there is a rim of air >2cm on the chest X-ray, this should be aspirated.
Aspiration is successful in approximately 70 per cent of patients; the patient may be discharged subsequently. A further attempt at aspiration is recommended if the patient remains symptomatic and a volume of less than 2.5 litres has been aspirated on the first attempt.

If unsuccessful, an intercostal drain is inserted. This may be removed after 24 hours after full re-expansion or cessation of air leak without clamping and discharge may be considered.

Burkholderia cepacia is an aerobic gram-negative bacillus found in various aquatic environments. B cepacia is an organism of low virulence and is a frequent colonizer of fluids used in the hospital (e.g., irrigation solutions, intravenous fluids).
B cepacia, as a non-aeruginosa pseudomonad, is usually resistant to aminoglycosides, antipseudomonal penicillin, and antipseudomonal third-generation cephalosporins and polymyxin B.
B cepacia is often susceptible to trimethoprim plus sulfamethoxazole (TMP-SMX), cefepime, meropenem, minocycline, and tigecycline and has varying susceptibility to fluoroquinolones.
Based on the options available, ceftazidime and aminoglycoside would be the best option.

The tumour has only invaded the visceral pleura and measures 3cm in the greatest dimension. Hence it is designated at T2. Ipsilateral peribronchial and/or hilar lymph node involvement would make it N1. There is no distal metastasis so M would be 0.

β-blockers are the class of drug most often chosen to treat glaucoma, although other medical therapies are available. Systemic absorption of timolol eye drops can cause unsuspected respiratory impairment and exacerbation of asthma. Physicians should be alert to the possibility of respiratory side-effects of topical therapy with β-blockers. Leukotriene antagonists and salbutamol are used in asthma treatment. HRT and ferrous sulphate do not lead to the exacerbation of asthma.

Pulmonary alveolar proteinosis (PAP) is a lung condition that is caused by a build-up of proteins and other substances in the alveoli. The alveoli are the part of the lungs that contain air. PAP has the following symptoms:
Shortness of breath, also called dyspnoea
Chest pain or tightness
Fever
Weight loss
Cough (sometimes, but not always)
Low levels of oxygen in the blood
Nail clubbing (abnormal growth of toenails or fingernails)

Serologic studies are generally not useful for PAP. Flexible bronchoscopy with bronchoalveolar lavage (BAL) remains the criterion standard. Elevated levels of the proteins SP-A and SP-D in serum and BAL fluid may be useful. Elevated titer of neutralizing autoantibody against GM-CSF (immunoglobulin G [IgG] isotype) in serum and BAL fluid may be useful. Recent studies have proposed that deficiency of GM-CSF causes pulmonary alveolar proteinosis (PAP); all patients studied had the antibody to GM-CSF. Serum lactate dehydrogenase (LDH) level is usually elevated, but this finding is nonspecific.

High-resolution computed tomography (HRCT) scan of the chest demonstrates areas of patchy ground-glass opacification with smooth interlobular septal thickening and intralobular interstitial thickening, which produces a polygonal pattern referred to as crazy paving.

Light microscopy of the lung parenchymal tissue shows alveoli filled with a granular PAS base-reactive and diastase-resistant eosinophilic material.

High Altitude Cerebral Oedema (HACE) is a severe and potentially fatal manifestation of high altitude illness and is often characterized by ataxia, fatigue, and altered mental status. HACE is often thought of as an extreme form/end-stage of Acute Mountain Sickness (AMS). Although HACE represents the least common form of altitude illness, it may progress rapidly to coma and death as a result of brain herniation within 24 hours, if not promptly diagnosed and treated.

HACE generally occurs after 2 days above 4000m but can occur at lower elevations (2500m) and with faster onset. Some, but not all, individuals will suffer from symptoms of AMS such as headache, insomnia, anorexia, nausea prior to transitioning to HACE. Some may also have concomitant High Altitude Pulmonary Oedema (HAPE). HACE in isolation is rare, but the absence of concomitant HAPE or symptoms of AMS prior to deterioration does not rule-out the presence of HACE.

Most cases develop as a progression of AMS and will include a history of recent ascent to altitude and prior complaints/findings of AMS including a headache, fatigue, nausea, insomnia, and/or light-headedness. Some may also have signs/symptoms of HAPE. Transition to HACE is heralded by signs of encephalopathy including ataxia (usually the earliest clinical finding) and altered mentation which may range from mild to severe. Other symptoms may include a more severe headache, difficulty speaking, lassitude, a decline in the level of consciousness, and/or focal neurological deficits or seizures.

The mainstay of treatment is the immediate descent of at least 1000m or until symptoms improve. If descent is not an option, one may use a portable hyperbaric chamber and/or supplemental oxygen to temporize illness, but this should never replace or delay evaluation/descent when possible. If available, dexamethasone 8mg for one dose, followed by 4mg every 6 hours should be given to adults via PO, IM, or IV routes.
Acetazolamide has proven to be beneficial in only a single clinical study. The suggested dosing regimen for Acetazolamide is 250 mg PO, given twice daily. Though effective in alleviating or temporizing symptoms, none of the adjunct treatment modalities are definitive or a replacement for an immediate descent.

Malignant mesothelioma is a type of cancer that occurs in the thin layer of tissue that covers the majority of the internal organs (mesothelium).
Malignant Mesothelioma (MM) is a rare but rapidly fatal and aggressive tumour of the pleura and peritoneum. Aetiology of all forms of mesothelioma is strongly associated with industrial pollutants, of which asbestos is the principal carcinogen.

Thoracoscopically guided biopsy should be performed if mesothelioma is suggested; the results are diagnostic in 98% of cases. No specific treatment has been found to be of benefit, except radiotherapy, which reduces seeding and invasion through percutaneous biopsy sites.

Median survival for patients with malignant mesothelioma is 11 months. It is almost always fatal.

Silicosis is a common occupational lung disease that is caused by the inhalation of crystalline silica dust. Silica is the most abundant mineral on earth. Workers that are involved for example in construction, mining, or glass production are among the individuals with the highest risk of developing the condition. Acute silicosis causes severe symptoms (e.g., exertional dyspnoea, cough with sputum) and has a very poor prognosis.
Chronic silicosis has a very variable prognosis and affected individuals may remain asymptomatic for several decades. However, radiographic signs are usually seen early on. Typical radiographic findings are calcifications of perihilar lymph nodes, diffuse ground glass opacities, large numbers of rounded, solitary nodules or bigger, confluent opacities. Avoiding further exposure to silica is crucial, especially since the only treatment available is symptomatic (e.g., bronchodilators). Silicosis is associated with an increased risk of tuberculosis and lung cancer. Berylliosis typically affects individuals who are exposed to aerospace industry. Histoplasmosis and tuberculosis do not form eggshell calcifications.

Salbutamol stimulates beta-2 adrenergic receptors, which are the predominant receptors in bronchial smooth muscle (beta-2 receptors are also present in the heart in a concentration between 10% and 50%).

Stimulation of beta-2 receptors leads to the activation of enzyme adenyl cyclase that forms cyclic AMP (adenosine-mono-phosphate) from ATP (adenosine-tri-phosphate). This increase of cyclic AMP relaxes bronchial smooth muscle and decrease airway resistance by lowering intracellular ionic calcium concentrations. Salbutamol relaxes the smooth muscles of airways, from trachea to terminal bronchioles.

Increased cyclic AMP concentrations also inhibits the release of bronchoconstrictor mediators such as histamine and leukotriene from the mast cells in the airway.

COPD is commonly associated with progressive hypoxemia. Oxygen administration reduces mortality rates in patients with advanced COPD because of the favourable effects on pulmonary hemodynamics.

Long-term oxygen therapy improves survival 2-fold or more in hypoxemic patients with COPD, according to 2 landmark trials, the British Medical Research Council (MRC) study and the US National Heart, Lung and Blood Institute’s Nocturnal Oxygen Therapy Trial (NOTT). Hypoxemia is defined as PaO2 (partial pressure of oxygen in arterial blood) of less than 55 mm Hg or oxygen saturation of less than 90%. Oxygen was used for 15-19 hours per day.

Therefore, specialists recommend long-term oxygen therapy for patients with a PaO2 of less than 55 mm Hg, a PaO2 of less than 59 mm Hg with evidence of polycythaemia, or cor pulmonale. Patients should be evaluated after 1-3 months after initiating therapy, because some patients may not require long-term oxygen.

The carotid body consists of chemosensitive cells at the bifurcation of the common carotid artery that respond to changes in oxygen tension and, to a lesser extent, pH. In contrast to central chemoreceptors (which primarily respond to PaCO2) and the aortic bodies (which primarily have circulatory effects: bradycardia, hypertension, adrenal stimulation, and also bronchoconstriction), carotid bodies are most sensitive to PaO2. At a PaO2 of approximately 55-60 mmHg, they send their impulses via CN IX to the medulla, increasing ventilatory drive (increased respiratory rate, tidal volume, and minute ventilation). Thus, patients who rely on hypoxic respiratory drive will typically have a resting PaO2 around 60 mm Hg.

Classic clinical features associated with active pulmonary TB are as follows (elderly individuals with TB may not display typical signs and symptoms):
– Cough
– Weight loss/anorexia
– Fever
– Night sweats
– Haemoptysis
– Chest pain (can also result from tuberculous acute pericarditis)
– Fatigue

Test:
Acid-fast bacilli (AFB) smear and culture – Using sputum obtained from the patient.
AFB stain is quick but requires a very high organism load for positivity, as well as the expertise to read the stained sample. This test is more useful in patients with pulmonary disease.
Obtain a chest radiograph to evaluate for possible associated pulmonary findings. If chest radiography findings suggest TB and a sputum smear is positive for AFB, initiate treatment for TB.

Meconium ileus equivalent (MIE) can be defined as a clinical manifestation in cystic fibrosis (CF) patients caused by acute intestinal obstruction by putty-like faecal material in the cecum or terminal ileum. A broader definition includes a more chronic condition in CF patients with abdominal pain and a coecal mass which may eventually pass spontaneously. The condition occurs only in CF patients with exocrine pancreatic insufficiency (EPI). It has not been seen in other CF patients nor in non-CF patients with EPI. The frequency of these symptoms has been reported as 2.4%-25%.

The treatment should primarily be non-operative. Specific treatment with N-acetylcysteine, administrated orally and/or as an enema is recommended. Enemas with the water soluble contrast medium, meglucamine diatrizoate (Gastrografin), provide an alternative form for treatment and can also serve diagnostic purposes. It is important that the physician is familiar with this disease entity and the appropriate treatment with the above mentioned drugs. Non-operative treatment is often effective, and dangerous complications following surgery can thus be avoided.

Type I pneumocyte: The cell responsible for the gas (oxygen and carbon dioxide) exchange that takes place in the alveoli. It is a very thin cell stretched over a very large area. This type of cell is susceptible to a large number of toxic insults and cannot replicate itself.
Type II pneumocyte: The cell responsible for the production and secretion of surfactant (the molecule that reduces the surface tension of pulmonary fluids and contributes to the elastic properties of the lungs). The type 2 pneumocyte is a smaller cell that can replicate in the alveoli and will replicate to replace damaged type 1 pneumocytes. Alveolar macrophages are the primary phagocytes of the innate immune system, clearing the air spaces of infectious, toxic, or allergic particles that have evaded the mechanical defences of the respiratory tract, such as the nasal passages, the glottis, and the mucociliary transport system. The main role of goblet cells is to secrete mucus in order to protect the mucous membranes where they are found. Goblet cells accomplish this by secreting mucins, large glycoproteins formed mostly by carbohydrates.

In mild-to-moderate heroin overdoses, arterial blood gas (ABG) analysis reveals respiratory acidosis. In more severe overdoses, tissue hypoxia is common, leading to mixed respiratory and metabolic acidosis.

The normal range for PaCO2 is 35-45 mmHg (4.67 to 5.99 kPa). Respiratory acidosis can be acute or chronic. In acute respiratory acidosis, the PaCO2 is elevated above the upper limit of the reference range (i.e., >45 mm Hg) with an accompanying academia (i.e., pH < 7.35). In chronic respiratory acidosis, the PaCO2 is elevated above the upper limit of the reference range, with a normal or near-normal pH secondary to renal compensation and an elevated serum bicarbonate levels (i.e., >30 mEq/L).

Arterial blood gases with pH = 7.31; pCO2 = 7.4 kPa; pO2 = 8.1 kPa would indicate respiratory acidosis.

The normal partial pressure reference values are:
– PaO2 more than 80 mmHg (11 kPa)
– PaCO2 less than 45 mmHg (6.0 kPa).
This patient has an elevated PaCO2 (7.4kPa)
Hypoxemia (PaO2 <8kPa) with hypercapnia (PaCO2 >6.0kPa).
The pH is also lower than 7.35 at 7.3

Type 2 respiratory failure is caused by inadequate alveolar ventilation; both oxygen and carbon dioxide are affected. Defined as the build-up of carbon dioxide levels (PaCO2) that has been generated by the body but cannot be eliminated. The underlying causes include:
– Increased airways resistance (chronic obstructive pulmonary disease, asthma, suffocation)
– Reduced breathing effort (drug effects, brain stem lesion, extreme obesity)
– A decrease in the area of the lung available for gas exchange (such as in chronic bronchitis)
– Neuromuscular problems (Guillain–Barré syndrome, motor neuron disease)
– Deformed (kyphoscoliosis), rigid (ankylosing spondylitis), or flail chest.

Whilst asthma and COPD are different diseases they cause similar symptoms, which can present a challenge in identifying which of the two diseases a patient is suffering from. COPD causes chronic symptoms and narrowed airways which do not respond to treatment to open them up. In the case of asthma the constriction of the airways through inflammation tends to come and go and treatment to reduce inflammation and to open up the airways usually works well.

COPD is more likely than asthma to cause a chronic cough with phlegm and is rare before the age of 35 whilst asthma is common in under-35s. Disturbed sleep caused by breathlessness and wheeze is more likely in cases of asthma, as is a history of allergies, eczema and hay fever. Differentiating between COPD and asthma requires a history of both symptoms and spirometry. The spirometry history should include post bronchodilator measurements, the degree of reversibility and, ideally, home monitoring which gives a history of diurnal variation.

Airflow Obstruction: Both asthma and COPD are characterised by airflow obstruction. Airflow obstruction is defined as a reduced FEV1 and a reduced FEV1/FVC ratio, such that FEV1 is less than 80% of that predicted, and FEV1/FVC is less than 0.7.

These episodes are usually associated with widespread, but variable, airflow obstruction within the lung that is often reversible either spontaneously or with treatment.

COPD: COPD is a chronic, slowly progressive disorder characterised by airflow obstruction (reduced FEV1 and FEV1/VC ratio) that does not change markedly over several months. The airflow obstruction is not fully reversible.

Spirometry COPD Asthma
VC Reduced Nearly normal
FEV1 Reduced Reduced in attack
FVC (or FEV6) Reduced Nearly normal
FEV1 Ratio
(of VC/FVC/FEV6) Reduced in attack

This man has a low FEV1 and FVC. His diffusions capacity is also low despite having a normal total lung capacity. These values confirm a diagnosis of COPD.

Peak Expiratory Flow (PEF), also called Peak Expiratory Flow Rate (PEFR) is a person’s maximum speed of expiration, as measured with a peak flow meter. Measurement of PEFR requires some practise to correctly use a meter and the normal expected value depends on a patient’s gender, age and height.
It is classically reduced in obstructive lung disorders, such as Asthma, COPD or Cystic Fibrosis.

Sarcoidosis is an inflammatory disease that affects one or more organs but most commonly affects the lungs and lymph glands. The inflammation may change the normal structure and possibly the function of the affected organ(s).
The presentation in sarcoidosis varies with the extent and severity of organ involvement, as follows:
Asymptomatic (incidentally detected on chest imaging): Approximately 5% of cases.
Systemic complaints (fever, anorexia): 45% of cases
Pulmonary complaints (dyspnoea on exertion, cough, chest pain, and haemoptysis [rare]): 50% of cases

Löfgren syndrome (fever, bilateral hilar lymphadenopathy, and polyarthralgias): Common in Scandinavian patients, but uncommon in African-American and Japanese patients.

Dermatologic manifestations may include the following:
– Erythema nodosum
– A lower-extremity panniculitis with painful, erythematous nodules (often with Löfgren syndrome)
– Lupus pernio (the most specific associated cutaneous lesion)
– Violaceous rash on the cheeks or nose (common)
– Maculopapular plaques (uncommon)

Staging of sarcoidosis is as follows:
Stage 0: Normal chest radiographic findings
Stage I: Bilateral hilar lymphadenopathy
Stage II: Bilateral hilar lymphadenopathy and infiltrates
Stage III: Infiltrates alone
Stage IV: Fibrosis

Nonsteroidal anti-inflammatory drugs (NSAIDs) are indicated for the treatment of arthralgias and other rheumatic complaints. Patients with stage I sarcoidosis often require only occasional treatment with NSAIDs.

Treatment in patients with pulmonary involvement is as follows:
Asymptomatic patients may not require treatment
In patients with minimal symptoms, serial re-evaluation is prudent
Treatment is indicated for patients with significant respiratory symptoms
Corticosteroids can produce small improvements in the functional vital capacity and in the radiographic appearance in patients with more severe stage II and III disease.

This patient has Stage 1 Sarcoidosis so observation is the most appropriate action.

Cavitating pneumonia is a complication that can occur with a severe necrotizing pneumonia and in some publications it is used synonymously with the latter term. It is a rare complication in both children and adults. Albeit rare, cavitation is most commonly caused by Streptococcus pneumoniae, and less frequently Aspergillus spp., Legionella spp. and Staphylococcus aureus.

In children, cavitation is associated with severe illness, although cases usually resolve without surgical intervention, and long-term follow-up radiography shows clear lungs without pulmonary sequelae
Although the absolute cavitary rate may not be known, according to one series, necrotizing changes were seen in up to 6.6% of adults with pneumococcal pneumonia. Klebsiella pneumoniae is another organism that is known to cause cavitation.

Causative agents:
Mycobacterium tuberculosis
Klebsiella pneumoniae
Streptococcus pneumoniae
Staphylococcus aureus

Enterococcus faecalis was not found to be a causative agent.

The NICE 2017 guidelines state that in patients who are uncontrolled with a SABA (Salbutamol) and ICS (Inhaled corticosteroid e.g. Beclomethasone), a leukotriene receptor antagonist (LTRA) should be added.
If asthma is uncontrolled in adults (aged 17 and over) on a low dose of ICS as maintenance therapy, offer a leukotriene receptor antagonist (LTRA) in addition to the ICS and review the response to treatment in 4 to 8 weeks.

This recommendation is also stated in NICE 2019 guidelines.

Lambert-Eaton myasthenic syndrome (LEMS) is a rare presynaptic disorder of neuromuscular transmission in which release of acetylcholine (ACh) is impaired, causing a unique set of clinical characteristics, which include proximal muscle weakness, depressed tendon reflexes, post-tetanic potentiation, and autonomic changes.

In 40% of patients with LEMS, cancer is present when the weakness begins or is found later. This is usually a small cell lung cancer (SCLC). However, LEMS has also been associated with non-SCLC, lymphosarcoma, malignant thymoma, or carcinoma of the breast, stomach, colon, prostate, bladder, kidney, or gallbladder.

Phrenic nerve palsy causing hemidiaphragm paralysis is a very uncommon feature of thoracic aortic aneurysm.

Thoracic aortic aneurysms are usually asymptomatic however chest pain is most commonly reported symptom. Left hemidiaphragm paralysis, because of left phrenic nerve palsy, is a very rare presentation of thoracic aortic aneurysm.
Thoracic aortic aneurysm may present atypical symptoms such as dysphagia due to compression of the oesophagus; hoarseness due to vocal cord paralysis or compression of the recurrent laryngeal nerve; superior vena cava syndrome due to compression of the superior vena cava; cough, dyspnoea or both due to tracheal compression; haemoptysis due to rupture of the aneurysm into a bronchus; and shock due to rupture of the aneurysm.
Common causes of phrenic nerve palsy include malignancy such as bronchogenic carcinoma, as well as mediastinal and neck tumours. Phrenic nerve palsy can also occur due to a penetrating injury or due to iatrogenic causes arising, for example, during cardiac surgery and central venous catheterization. Many cases or phrenic nerve palsy are idiopathic.

Assess the need for oxygen therapy in people with:
– very severe airflow obstruction (FEV1 below 30% predicted)
– cyanosis (blue tint to skin)
– polycythaemia
– peripheral oedema (swelling)
– a raised jugular venous pressure
– oxygen saturations of 92% or less breathing air.

Also consider assessment for people with severe airflow obstruction (FEV1 30–49% predicted).

Consider long-term oxygen therapy for people with COPD who do not smoke and who:
have a partial pressure of oxygen in arterial blood (PaO2) below 7.3 kPa when stable or have a PaO2 above 7.3 and below 8 kPa when stable, if they also have 1 or more of the following:
– secondary polycythaemia
– peripheral oedema
– pulmonary hypertension.

High-resolution CT (HRCT) scanning is more sensitive than standard chest radiography and is highly specific for diagnosing emphysema (outlined bullae are not always visible on a radiograph).

HRCT scanning may provide an adjunct means of diagnosing various forms of COPD (i.e., lower lobe disease may suggest AAT deficiency) and may help the clinician to determine whether surgical intervention would benefit the patient.

Studies have shown that benefits of Long-tern oxygen therapy (LTOT) include improved exercise tolerance, with improved walking distance, and ability to perform daily activities, reduction of secondary polycythaemia, improved sleep quality and reduced sympathetic outflow, with increased sodium and water excretion, leading to improvement in renal function.

CURB Pneumonia Severity Score estimates the mortality of community-acquired pneumonia to help determine inpatient vs. outpatient treatment.
Select Criteria:
Confusion (abbreviated Mental Test Score <=8) (1 point)
Urea (BUN > 19 mg/dL or 7 mmol/L) (1 point)
Respiratory Rate > 30 per minute (1 point)
Blood Pressure: diastolic < 60 or systolic < 90 mmHg (1 point) The CURB-65 scores range from 0 to 5. Clinical management decisions can be made based on the score:
Score Risk Disposition
0 or 1 – 1.5% mortality – Outpatient care
2 – 9.2% mortality – Inpatient vs. observation admission
≥ 3 – 22% mortality – Inpatient admission with consideration for ICU admission with score of 4 or 5

Extrinsic allergic alveolitis (EAA) refers to a group of lung diseases that can develop after exposure to certain substances. The name describes the origin and the nature of these diseases:

‘extrinsic’ – caused by something originating outside the body
‘allergic’ – an abnormally increased (hypersensitive) body reaction to a common substance
‘alveolitis’ – inflammation in the small air sacs of the lungs (alveoli)

Symptoms can include: fever, cough, worsening breathlessness and weight loss. The diagnosis of the disease is based on a history of symptoms after exposure to the allergen and a range of clinical tests which usually includes: X-rays or CT scans, lung function and blood tests.

EAA is not a ‘new’ occupational respiratory disease and occupational causes include bacteria, fungi, animal proteins, plants and chemicals.

Examples of EAA include:

Bird fancier’s lung (BFL) is a type of hypersensitivity pneumonitis (HP). It is triggered by exposure to avian proteins present in the dry dust of the droppings and sometimes in the feathers of a variety of birds. The lungs become inflamed, with granuloma formation. Birds such as pigeons, parakeets, cockatiels, shell parakeets (budgerigars), parrots, turtle doves, turkeys and chickens have been implicated.

People who work with birds or own many birds are at risk. Bird hobbyists and pet store workers may also be at risk. This disease is an inflammation of the alveoli in the lungs caused by an immune response to inhaled allergens from birds. Initial symptoms include shortness of breath (dyspnoea), especially after sudden exertion or when exposed to temperature change, which can resemble asthma, hyperventilation syndrome or pulmonary embolism. Chills, fever, non-productive cough and chest discomfort may also occur.

A definitive diagnosis can be difficult without invasive testing, but extensive exposure to birds combined with reduced diffusing capacity are strongly suggestive of this disease. X-ray or CT scans will show physical changes to the lung structure (a ground glass appearance) as the disease progresses. Precise distribution and types of tissue damage differ among similar diseases, as does response to treatment with Prednisone.

Infection with Klebsiella organisms occurs in the lungs, where they cause destructive changes. Necrosis, inflammation, and haemorrhage occur within lung tissue, sometimes producing a thick, bloody, mucoid sputum described as currant jelly sputum.
The illness typically affects middle-aged and older men with debilitating diseases such as alcoholism, diabetes, or chronic bronchopulmonary disease. An increased tendency exists toward abscess formation, cavitation, empyema, and pleural adhesions.

Alveolar haemorrhage (AH) is a rare, but serious manifestation of SLE. It may occur early or late in disease evolution. Extrapulmonary disease may be minimal and may be masked in patients who are already receiving immunosuppressants for other symptoms of SLE.

DLCO or TLCO (diffusing capacity or transfer factor of the lung for carbon monoxide (CO)) is the extent to which oxygen passes from the air sacs of the lungs into the blood.
Factors that can increase the DLCO include polycythaemia, asthma (can also have normal DLCO) and increased pulmonary blood volume as occurs in exercise. Other factors are left to right intracardiac shunting, mild left heart failure (increased blood volume) and alveolar haemorrhage (increased blood available for which CO does not have to cross a barrier to enter).

Carbon monoxide (CO) is a colourless, odourless gas produced by incomplete combustion of carbonaceous material. Clinical presentation in patients with CO poisoning ranges from headache and dizziness to coma and death. Hyperbaric oxygen therapy can significantly reduce the morbidity of CO poisoning, but a portion of survivors still suffer significant long-term neurologic and affective sequelae.

Complaints:
Malaise, flulike symptoms, fatigue
Dyspnoea on exertion
Chest pain, palpitations
Lethargy
Confusion
Depression
Impulsiveness
Distractibility
Hallucination, confabulation
Agitation
Nausea, vomiting, diarrhoea
Abdominal pain
Headache, drowsiness
Dizziness, weakness, confusion
Visual disturbance, syncope, seizure
Faecal and urinary incontinence
Memory and gait disturbances
Bizarre neurologic symptoms, coma

Vital signs may include the following:
Tachycardia
Hypertension or hypotension
Hyperthermia
Marked tachypnoea (rare; severe intoxication often associated with mild or no tachypnoea)
Although so-called cherry-red skin has traditionally been considered a sign of CO poisoning, it is in fact rare.

The clinical diagnosis of acute carbon monoxide (CO) poisoning should be confirmed by demonstrating an elevated level of carboxyhaemoglobin (HbCO). Either arterial or venous blood can be used for testing. Analysis of HbCO requires direct spectrophotometric measurement in specific blood gas analysers. Elevated CO levels of at least 3–4% in non-smokers and at least 10% in smokers are significant.

A study conducted showed that the average post smoking cessation weight gain was about 2 kg.
Withdrawal symptoms usually peak after 1–3 days and then decrease over a period of 3–4 weeks. After this time, the body has expelled most of the nicotine, and the withdrawal effects are mainly psychological.

Bronchiectasis is a long-term condition where the airways of the lungs become abnormally widened, leading to a build-up of excess mucus that can make the lungs more vulnerable to infection. The most common symptoms of bronchiectasis include:
– a persistent productive cough
– breathlessness.

The 3 most common causes in the UK are:
– a lung infection in the past, such as pneumonia or whooping cough, that damages the bronchi
– underlying problems with the immune system (the body’s defence against infection) that make the bronchi more vulnerable to damage from an infection
– allergic bronchopulmonary aspergillosis (ABPA) – an allergy to a certain type of fungi that can cause the bronchi to become inflamed if spores from the fungi are inhaled

Acute epiglottitis is a life-threatening disorder with serious implications to the anaesthesiologist because of the potential for laryngospasm and irrevocable loss of the airway. There is inflammatory oedema of the arytenoids, aryepiglottic folds and the epiglottis; therefore, supraglottitis may be used instead or preferred to the term acute epiglottitis.

Acute epiglottitis can occur at any age. The responsible organism used to be Hemophilus influenzae type B (Hib), but infection with group A b-haemolytic Streptococci has become more frequent after the widespread use of Hemophilus influenzae vaccination.

The typical presentation in epiglottitis includes acute occurrence of high fever, severe sore throat and difficulty in swallowing with the sitting up and leaning forward position in order to enhance airflow. There is usually drooling because of difficulty and pain on swallowing. Acute epiglottitis usually leads to generalized toxaemia. The most common differential diagnosis is croup and a foreign body in the airway. A late referral to an acute care setting with its serious consequences may result from difficulty in differentiation between acute epiglottitis and less urgent causes of a sore throat, shortness of breath and dysphagia.

V/Q scanning carries a slightly increased risk of childhood cancer compared with CTPA – 1/280,000 versus less than 1/1,000,000 – but carries a lower risk of maternal breast cancer. The rest of the options are true.

Asthma is a condition characterized by airway hyperresponsiveness, which results in reversible increases in bronchial smooth muscle tone, and variable amounts of inflammation of the bronchial mucosa.
During an acute asthma attack, the already inflamed airways narrow further due to bronchospasm, which leads to increased airway resistance. Because of the increased smooth muscle tone during an asthma attack, the airways also tend to close at abnormally high lung volumes, trapping air behind occluded or narrowed small airways. Thus the acute asthmatic will breathe at high lung volumes, his functional residual capacity will be elevated, and he will inspire close to total lung capacity. The accessory muscles of respiration are often used to maintain the lungs in a hyperinflated state.

During episodes of acute asthma, pulmonary function tests reveal an obstructive pattern. This includes a decrease in the rate of maximal expiratory air flow (a decrease in FEV1 and the FEV1/FVC ratio) due to the increased resistance, and a reduction in forced vital capacity (FVC) correlating with the level of hyperinflation of the lungs. Because these patients breathe at such high lung volumes (near the top of the pressure-volume curve, where lung compliance greatly decreases), they must exert significant effort to create an extremely negative pleural pressure, and consequently fatigue easily. Overinflation also reduces the curvature of the diaphragm, making it less efficient in generating further negative pleural pressure.

A single dose of intravenous magnesium sulphate is safe and may improve lung function and reduce intubation rates in patients with acute severe asthma. Intravenous magnesium sulphate may also reduce hospital admissions in adults with acute asthma who have had little or no response to standard treatment.

Consider giving a single dose of intravenous magnesium sulphate to patients with acute severe asthma (PEF <50% best or predicted) who have not had a good initial response to inhaled bronchodilator therapy. Magnesium sulphate (1.2–2 g IV infusion over 20 minutes) should only be used following consultation with senior medical staff.

A retrospective cohort study of the primary care records of 247 lung cancer patients diagnosed between 1998–2002 showed that 10% of the X-rays were reported as normal.
Other tests may include:
– Imaging tests: A CT scan can reveal small lesions in your lungs that might not be detected on an X-ray.
– Sputum cytology: sputum may reveal the presence of lung cancer cells.
– Tissue sample (biopsy): A sample of abnormal cells may be removed for histological analysis. A biopsy may be performed in a number of ways, including bronchoscopy, mediastinoscopy and needle biopsy. A biopsy sample may also be taken from adjacent lymph nodes.

Community-acquired pneumonia (CAP) is one of the most common infectious diseases and is an important cause of mortality and morbidity worldwide. Typical bacterial pathogens that cause CAP include Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis.
The CURB-65 is used as a means of deciding the action that is needed to be taken for that patient.
Score 3-5: Requires hospitalization with consideration as to whether they need to be in the intensive care unit

Recent studies have suggested that the use of a beta-lactam alone may be noninferior to a beta-lactam/macrolide combination or fluoroquinolone therapy in hospitalized patients.

Therapy in ICU patients includes the following:
– Beta-lactam (ceftriaxone, cefotaxime, or ampicillin/sulbactam) plus either a macrolide or respiratory fluoroquinolone
– For patients with penicillin allergy, a respiratory fluoroquinolone and aztreonam

Therefore the appropriate treatment would be Cefotaxime and erythromycin.

Extrinsic allergic alveolitis (EAA) refers to a group of lung diseases that can develop after exposure to certain substances. The name describes the origin and the nature of these diseases:

‘extrinsic’ – caused by something originating outside the body
‘allergic’ – an abnormally increased (hypersensitive) body reaction to a common substance
‘alveolitis’ – inflammation in the small air sacs of the lungs (alveoli)

Symptoms can include: fever, cough, worsening breathlessness and weight loss. The diagnosis of the disease is based on a history of symptoms after exposure to the allergen and a range of clinical tests which usually includes: X-rays or CT scans, lung function and blood tests.

EAA is not a ‘new’ occupational respiratory disease and occupational causes include bacteria, fungi, animal proteins, plants and chemicals.

Examples of EAA include:

Farmer’s lung
This is probably the most common occupational form of EAA and is the outcome of an allergic response to a group of microbes, which form mould on vegetable matter in storage. During the handling of mouldy straw, hay or grain, particularly in a confined space such as a poorly ventilated building, inhalation of spores and other antigenic material is very likely.

There also appears to be a clear relationship between water content of crops, heating (through mould production) and microbial growth, and this would apply to various crops and vegetable matter, with the spores produced likely to cause EAA.

Farmer’s lung can be prevented by drying crops adequately before storage and by ensuring good ventilation during storage. Respiratory protection should also be worn by farm workers when handling stored crops, particularly if they have been stored damp or are likely to be mouldy.

Caplan’s syndrome is defined as the association between silicosis and rheumatoid arthritis (RA). It is rare and usually diagnosed in an advanced stage of RA. It generally affects patients with a prolonged exposure to silica.

Caplan’s syndrome presents with rheumatoid lung nodules and pneumoconiosis. Originally described in coal miners with progressive massive fibrosis, it may also occur in asbestosis, silicosis and other pneumoconiosis. Chest radiology shows multiple, round, well defined nodules, usually 0.5 – 2.0 cm in diameter, which may cavitate and resemble tuberculosis.

Churg-Strauss disease (CSD) is one of three important fibrinoid, necrotizing, inflammatory leukocytoclastic systemic small-vessel vasculitides that are associated with antineutrophil cytoplasm antibodies (ANCAs).
The first (prodromal) phase of Churg-Strauss disease (CSD) consists of asthma usually in association with other typical allergic features, which may include eosinophilia. During the second phase, the eosinophilia is characteristic (see below) and ANCAs with perinuclear staining pattern (pANCAs) are detected. The treatment would therefore be different from asthma. For most patients, especially those patients with evidence of active vasculitis, treatment with corticosteroids and immunosuppressive agents (cyclophosphamide) is considered first-line therapy

The phrenic nerve provides the primary motor supply to the diaphragm, the major respiratory muscle.
Phrenic nerve paralysis is a rare cause of exertional dyspnoea that should be included in the differential diagnosis. Fluoroscopy is considered the most reliable way to document diaphragmatic paralysis. During fluoroscopy a patient is asked to sniff and there is a paradoxical rise of the paralysed hemidiaphragm. This is to confirm that the cause is due to paralysis rather than unilateral weakness.

Methotrexate lung disease (pneumonitis and fibrosis) is the specific etiological type of drug-induced lung disease. It can occur due to the administration of methotrexate which is an antimetabolite, which is given as disease-modifying antirheumatic drugs (DMARDs) in patients with rheumatoid arthritis. The typical clinical symptoms include progressive shortness of breath and cough, often associated with fever. Hypoxemia and tachypnoea are always present and crackles are frequently audible. Symptoms typically manifest within months of starting therapy. Methotrexate withdrawal is indicated in such cases.

An aspergilloma is a fungus ball (mycetoma) that develops in a pre-existing cavity in the lung parenchyma. Underlying causes of the cavitary disease may include treated tuberculosis or other necrotizing infection, sarcoidosis, cystic fibrosis, and emphysematous bullae. The ball of fungus may move within the cavity but does not invade the cavity wall. Aspergilloma may manifest as an asymptomatic radiographic abnormality in a patient with pre-existing cavitary lung disease due to sarcoidosis, tuberculosis, or other necrotizing pulmonary processes. In patients with HIV disease, aspergilloma may occur in cystic areas resulting from prior Pneumocystis jiroveci pneumonia. Of patients with aspergilloma, 40-60% experience haemoptysis, which may be massive and life threatening. Less commonly, aspergilloma may cause cough and fever.

Lofgren’s syndrome is an acute form of sarcoidosis characterized by erythema nodosum, bilateral hilar lymphadenopathy (BHL), and polyarthralgia or polyarthritis. Other symptoms include anterior uveitis, fever, ankle periarthritis, and pulmonary involvement.

Löfgren syndrome is usually an acute disease with an excellent prognosis, typically resolving spontaneously from 6-8 weeks to up to 2 years after onset. Pulmonologists, ophthalmologists, and rheumatologists often define this syndrome differently, describing varying combinations of arthritis, arthralgia, uveitis, erythema nodosum, hilar adenopathy, and/or other clinical findings.

Allergic bronchopulmonary aspergillosis (ABPA) is a form of lung disease that occurs in some people who are allergic to Aspergillus. With ABPA, this allergic reaction causes the immune system to overreact to Aspergillus leading to lung inflammation. ABPA causes bronchospasm (tightening of airway muscles) and mucus build-up resulting in coughing, breathing difficulty and airway obstruction.

Blood tests are used to look for signs of an allergic reaction. This includes evaluating your immunoglobulin E (IgE) level. This level is increased with any type of allergy. Many people with asthma have higher than normal IgE levels. In ABPA however, the IgE level is extremely high (more than 1000 ng/ml or 417 IU/ml). In addition to total IgE, all patients with ABPA have high levels of IgE that is specific to Aspergillus. A blood test can be done to measure specific IgE to Aspergillus. A blood or skin test for IgE antibodies to Aspergillus can be done to see if a person is sensitized (allergic) to this fungus. If these skin tests are negative (i.e. does not show a skin reaction) to Aspergillus fumigatus, the person usually does not have ABPA.
Therefore, there should be no change in medication since this patient does not have ABPA.

Flow-volume loop is an easy, non-invasive diagnostic tool that can be used even in severely-ill patients. It can provide information about the location of the obstruction and can differentiate between obstructive pulmonary disease and upper-airway obstruction. Therefore, it is recommended to obtain a flow-volume loop during the assessment of patients with upper airway obstruction.

Alpha-1 antitrypsin deficiency is an inherited disorder that may cause lung and liver disease. The signs and symptoms of the condition and the age at which they appear vary among individuals. This would be the most likely option as it is the only disease that can affect both liver and lung functions.
People with alpha-1 antitrypsin deficiency usually develop the first signs and symptoms of lung disease between ages 20 and 50. The earliest symptoms are shortness of breath following mild activity, reduced ability to exercise, and wheezing. Other signs and symptoms can include unintentional weight loss, recurring respiratory infections, fatigue, and rapid heartbeat upon standing. Affected individuals often develop emphysema. Characteristic features of emphysema include difficulty breathing, a hacking cough, and a barrel-shaped chest. Smoking or exposure to tobacco smoke accelerates the appearance of emphysema symptoms and damage to the lungs.
About 10 percent of infants with alpha-1 antitrypsin deficiency develop liver disease, which often causes yellowing of the skin and sclera (jaundice). Approximately 15 percent of adults with alpha-1 antitrypsin deficiency develop liver damage (cirrhosis) due to the formation of scar tissue in the liver. Signs of cirrhosis include a swollen abdomen, swollen feet or legs, and jaundice. Individuals with alpha-1 antitrypsin deficiency are also at risk of developing hepatocellular carcinoma.

The normal partial pressure reference values are: oxygen PaO2 more than 80 mmHg (11 kPa), and carbon dioxide PaCO2 lesser than 45 mmHg (6.0 kPa).
This patient has an elevated PaCO2 of 6.8kPa which exceeds the normal value of less than 6.0kPa.
The pH is also lower than 7.35 at 7.32

In any patient with asthma, an increasing PaCO2 indicates severe airway obstruction that is leading to respiratory muscle fatigue and patient exhaustion.

According to the British Thoracic Society guidelines:
Indications for admission to intensive care or high-dependency units include
patients requiring ventilatory support and those with acute severe or life-threatening asthma who are failing to respond to therapy, as evidenced by:
• deteriorating PEF
• persisting or worsening hypoxia
• hypercapnia
• arterial blood gas analysis showing fall in pH or rising hydrogen concentration
• exhaustion, feeble respiration
• drowsiness, confusion, altered conscious state
• respiratory arrest

Transfer to ICU accompanied by a doctor prepared to intubate if:
• Deteriorating PEF, worsening or persisting hypoxia, or hypercapnia
• Exhaustion, altered consciousness
• Poor respiratory effort or respiratory arrest

A single dose of intravenous magnesium sulphate is safe and may improve lung function and reduce intubation rates in patients with acute severe asthma. Intravenous magnesium sulphate may also reduce hospital admissions in adults with acute asthma who have had little or no response to standard treatment.

Consider giving a single dose of intravenous magnesium sulphate to
patients with acute severe asthma (PEF <50% best or predicted) who have not had a good initial response to inhaled bronchodilator therapy.
Magnesium sulphate (1.2–2 g IV infusion over 20 minutes) should only be used following consultation with senior medical staff.

Post-primary pulmonary tuberculosis is a chronic disease commonly caused by either endogenous reactivation of a latent infection or exogenous re-infection by Mycobacterium tuberculosis.
Post-primary pulmonary tuberculosis (also called reactivation tuberculosis) develops in 5%–20% of patients infected with M. tuberculosis.

Found mainly in adults, this form of tuberculosis arises from the reactivation of bacilli that lay dormant within a fibrotic area of the lung. In adults, reinfection with a strain of mycobacterium that differs from that which caused the primary infection is also possible. Predisposing factors include immunosuppression, diabetes, malnutrition and alcoholism.

Infliximab is a monoclonal antibody against tumour necrosis factor α (TNF-α). It is FDA approved for many autoimmune conditions, including rheumatoid arthritis and Crohn’s disease. One of the many known side effects of infliximab therapy is reactivation of latent tuberculosis (TB). Because of the resemblances in clinical and radiological features, tubercular lesions in the lung may mimic malignancy. TB accounts for 27% of all infections initially presumed to be lung cancer on imaging studies.

Bronchial carcinoids are uncommon, slow growing, low-grade, malignant neoplasms, comprising 1-2% of all primary lung cancers.
It is believed to be derived from surface of bronchial glandular epithelium. Mostly located centrally, they produce symptoms and signs of bronchial obstruction such as localized wheeze, non resolving recurrent pneumonitis, cough, chest pain, and fever. Haemoptysis is present in approximately 50% of the cases due to their central origin and hypervascularity.
Central bronchial carcinoids are more common than the peripheral type and are seen as endobronchial nodules or hilar/perihilar mass closely related to the adjacent bronchus. Chest X-ray may not show the central lesion depending on how small it is.

Acute exacerbations of chronic obstructive pulmonary disease (COPD) are immediately treated with inhaled beta2 agonists and inhaled anticholinergics, followed by antibiotics (if indicated) and systemic corticosteroids. Methylxanthine therapy may be considered in patients who do not respond to other bronchodilators.
High flow oxygen would worsen his symptoms. Usually titrated oxygen (88 to 92 %) is given in such patients to avoid the risk of hyperoxic hypercarbia in which increasing oxygen saturation in a chronic carbon dioxide retainer can inadvertently lead to respiratory acidosis and death.

The Stages of COPD:
Mild COPD or Stage 1—Mild COPD with a FEV1 about 80 percent or more of normal.
Moderate COPD or Stage 2—Moderate COPD with a FEV1 between 50 and 80 percent of normal.
Severe COPD or Stage 3—Severe emphysema with a FEV1 between 30 and 50 percent of normal.
Very Severe COPD or Stage 4—Very severe or End-Stage COPD with a lower FEV1 than Stage 3, or people with low blood oxygen levels and a Stage 3 FEV1.

This patient has a FEV1 percent of 40 which falls within the stage 2 or moderate COP

The chance of two carriers of a recessive gene having a child that is homozygous for that disease (that is both genes are transmitted to the child) is 25%. Therefore, the chances of this couple having a child with CF are 25%(1/4) x 1/20 = 1/80.

The Stages of COPD:
Mild COPD or Stage 1—Mild COPD with a FEV1 about 80 percent or more of normal.
Moderate COPD or Stage 2—Moderate COPD with a FEV1 between 50 and 80 percent of normal.
Severe COPD or Stage 3—Severe emphysema with a FEV1 between 30 and 50 percent of normal.
Very Severe COPD or Stage 4—Very severe or End-Stage COPD with a lower FEV1 than Stage 3, or people with low blood oxygen levels and a Stage 3 FEV1.

This patient has a FEV1 percent of 37 which falls within the stage 3 or severe COPD.
During stage 3 COPD, you will likely experience significant lung function impairment. Many patients will experience an increase in COPD flare-ups or exacerbations. For some people, the increase in flare-ups means they could need to be hospitalized at times as well.

Inhaled corticosteroid (ICS) use in combination with long-acting β2-agonists (LABAs) was shown to provide improved reductions in exacerbations, lung function, and health status. ICS-LABA combination therapy is currently recommended for patients with a history of exacerbations despite treatment with long-acting bronchodilators alone. The presence of eosinophilic bronchial inflammation, detected by high blood eosinophil levels or a history of asthma or asthma–COPD overlap, may define a population of patients in whom ICSs may be of particular benefit.

The Towards a Revolution in COPD Health (TORCH) trial was a pivotal, double-blind, placebo-controlled, randomized study comparing salmeterol plus fluticasone propionate (50 and 500 µg, respectively, taken twice daily) with each component alone and placebo over 3 years.26 Patients with COPD were enrolled if they had at least a 10-pack-year smoking history, FEV1 <60% predicted, and an FEV1:FVC ratio ≤0.70.26 Among 6,184 randomized patients, the risk of death was reduced by 17.5% with the ICS-LABA combination vs placebo (P=0.052). ICS-LABA significantly reduced the rate of exacerbations by 25% compared with placebo (P<0.001) and improved health status and FEV1 compared with either component alone or placebo.

Primary spontaneous pneumothorax is an abnormal accumulation of air in the space between the lungs and the chest cavity (called the pleural space) that can result in the partial or complete collapse of a lung. This type of pneumothorax is described as primary because it occurs in the absence of lung disease such as emphysema. Spontaneous means the pneumothorax was not caused by an injury such as a rib fracture. Primary spontaneous pneumothorax is likely due to the formation of small sacs of air (blebs) in lung tissue that rupture, causing air to leak into the pleural space. Air in the pleural space creates pressure on the lung and can lead to its collapse. A person with this condition may feel chest pain on the side of the collapsed lung and shortness of breath. Patients are typically aged 18-40 years, tall, thin, and, often, are smokers.

In small pneumothoraxes with minimal symptoms, no active treatment is required. These patients can be safely discharged with early outpatient review and should be given written advice to return if breathlessness worsens. Patients who have been discharged without intervention should be advised that air travel should be avoided until a radiograph has confirmed resolution of the pneumothorax.

Subcutaneous low molecular weight heparin (LMWH) is the preferred treatment for most patients with acute DVT, including in pregnancy. A large meta-analyses comparing LMWH to unfractionated heparin (UFH) showed that LMWH decreased the risk of mortality, recurrent veno-thrombo embolism (VTE), and haemorrhage compared with heparin. Other advantages of LMWH may include more predictable therapeutic response, ease of administration and monitoring, and less heparin-induced thrombocytopenia. Disadvantages of LMWH include cost and longer half-life compared with heparin.

Warfarin, which is administered orally, is used if long-term anticoagulation is needed. The international normalized ratio (INR) is followed, with a target range of 2-3. Warfarin crosses the placenta and is teratogenic, causing a constellation of anomalies known as warfarin embryopathy, with greatest risk between the sixth and twelfth week of gestation.
Other options are not indicated for use.

Bronchopneumonia presents as a patchy consolidation involving one or more lobes, usually the dependent lung zones, a pattern attributable to aspiration of oropharyngeal contents.

Symptoms of bronchopneumonia may be like other types of pneumonia. This condition often begins with flu-like symptoms that can become more severe over a few days. The symptoms include:
– fever
– a cough that brings up mucus
– shortness of breath
– chest pain
– rapid breathing
– sweating
– chills
– headaches
– muscle aches
– pleurisy, or chest pain that results from inflammation due to excessive coughing
– fatigue
– confusion or delirium, especially in older people

There are several factors that can increase your risk of developing bronchopneumonia. These include:
– Age: People who are 65 years of age or older, and children who are 2 years or younger, have a higher risk for developing bronchopneumonia and complications from the condition.
– Environmental: People who work in, or often visit, hospital or nursing home facilities have a higher risk for developing bronchopneumonia.
– Lifestyle: Smoking, poor nutrition, and a history of heavy alcohol use can increase your risk for bronchopneumonia.
– Medical conditions: Having certain medical conditions can increase your risk for developing this type of pneumonia. These include: chronic lung disease, such as asthma or chronic obstructive pulmonary disease (COPD), HIV/AIDS, having a weakened immune system due to chemotherapy or the use of immunosuppressive drugs.