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.

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.

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 (AAT) is a member of the serine proteinase inhibitor (serpin) family of proteins with a broad spectrum of biological functions including inhibition of proteases, immune modulatory functions, and the transport of hormones.

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.

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.

Occupational asthma (OA) could be divided into a nonimmunological, irritant-induced asthma and an immunological, allergy-induced asthma. In addition, allergy-induced asthma can be caused by two different groups of agents: high molecular weight proteins (>5,000 Da) or low molecular weight agents (<5,000 Da), generally chemicals like the isocyanates.
Isocyanates are very reactive chemicals characterized by one or more isocyanate groups (–N=C=O). The main reactions of this chemical group are addition reactions with ethanol, resulting in urethanes, with amines (resulting in urea derivates) and with water. Here, the product is carbamic acid which is not stable and reacts further to amines, releasing free carbon dioxide.

Diisocyanates and polyisocyanates are, together with the largely nontoxic polyol group, the basic building blocks of the polyurethane (PU) chemical industry, where they are used solely or in combination with solvents or additives in the production of adhesives, foams, elastomers, paintings, coatings and other materials.

The complex salts of platinum are one of the most potent respiratory sensitising agents having caused occupational asthma in more than 50% of exposed workers. Substitution of ammonium hexachlor platinate with platinum tetra amine dichloride in the manufacture of catalyst has controlled the problem in the catalyst industry. Ammonium hexachlorplatinate exposure still occurs in the refining process.

Rosin based solder flux fume is produced when soldering. This fume is a top cause of occupational asthma.

Bakeries, flour mills and kitchens where flour dust and additives in the flour are a common cause of occupational asthma.

Cadmium was not found to cause occupational asthma.

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.

Pulmonary metastasis is seen in 20-54% of extrathoracic malignancies. The lungs are the second most frequent site of metastases from extrathoracic malignancies. Twenty percent of metastatic disease is isolated to the lungs. The development of pulmonary metastases in patients with known malignancies indicates disseminated disease and places the patient in stage IV in TNM (tumour, node, metastasis) staging systems.
Chest radiography (CXR) is the initial imaging modality used in the detection of suspected pulmonary metastasis in patients with known malignancies. Chest CT scanning without contrast is more sensitive than CXR.
Breast, colorectal, lung, kidney, head and neck, and uterus cancers are the most common primary tumours with lung metastasis at autopsy. Choriocarcinoma, osteosarcoma, testicular tumours, malignant melanoma, Ewing sarcoma, and thyroid cancer frequently metastasize to lung, but the frequency of these tumours is low.

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.