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.

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.

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.

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).

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.

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]).

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.

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.

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.

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.