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.

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.

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.

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.

The vas deferens is a long tube that connects the epididymis to the ejaculatory ducts. It acts as a canal through which mature sperm may pass through the penis during ejaculation.

Most men with CF (97-98 percent) are infertile because of a blockage or absence of the vas deferens, known as congenital bilateral absence of the vas deferens (CBAVD). The sperm never makes it into the semen, making it impossible for them to reach and fertilize an egg through intercourse. The absence of sperm in the semen can also contribute to men with CF having thinner ejaculate and lower semen volume.

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.

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.

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.

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.

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.