All the symptoms of this patient are characteristic features of tuberculosis. The ideal test is the acid fast bacilli test for sputum, it will confirm the preserve of Mycobacterium Tuberculosis using the Ziehl-Nelson stain.

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.

Destructive lesions of the thoracic inlet is related to the apical lung cancer called Pancoast tumour, along with the involvement of cervical sympathetic nerves (the stellate ganglion) and brachial plexus which can lead to a Horner’s syndrome

Masses in the middle mediastinum most commonly represent lymph nodes that are enlarged by a malignant, infectious, or inflammatory process. Masses in the posterior mediastinum are usually benign tumours or cysts originating from either the nerves that are present in this area (neurogenic tumours) or from the oesophagus (foregut duplication cysts). Lymph node biopsy would be the ideal choice of investigation in this case.

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.

Pneumothorax refers to a condition in which air or gases accumulate inside the pleural space causing the lungs to collapse. Because the patient did not have a history of any previous pulmonary disease or trauma, this is a case of simple pneumothorax.

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.

Lofgren’s syndrome is characterised by a triad of erythema nodosum, arthritis and bilateral lymphadenopathy. It is a variant of sarcoidosis.

Extrinsic allergic alveolitis, also known as hypersensitivity pneumonitis, is an allergic response of the lungs to an environmental allergen. Nodular shadowing in the chest X-ray is characteristic of extrinsic allergic alveolitis.
Churg-Strauss syndrome is an auto-immune disorder that is known to cause vasculitis mostly in patients having a pre-existing airway disease.
Cryptogenic organizing pneumonia is an inflammatory condition of the alveoli. The CXR of which shows ground-glass opacifications.
The CXR of progressive massive fibrosis also shows opacifications normally in the upper lung lobes.

Hypogammaglobulinemia occurs due to a variety of underlying primary or secondary immunodeficient states, including HIV which is suspected in this case. The most commonly recognised clinical feature is recurrent infection.

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.

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.

Aminophylline is a very effective bronchodilator. It is short acting and therefore very effective in acute scenarios.

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.

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.

The history of smoking with a cough and bone pain is suggestive of bronchogenic carcinoma. CXR findings are also supportive of this diagnosis. In COPD, a cough with dyspnoea and wheezing is prominent.

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.

The NICE 2019 guidelines states that in patients who are uncontrolled with a SABA (Salbutamol) and ICS (Beclomethasone), 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.

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]).