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.

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.

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.

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.

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.

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.

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.

Alpha1-antitrypsin (AAT) deficiency, first described in 1963, is one of the most common inherited disorders amongst white Caucasians. Its primary manifestation is early-onset of pan acinar emphysema. In adults, alpha1-antitrypsin deficiency leads to chronic liver disease in the fifth decade. As a cause of emphysema, it is seen in non-smokers in the fifth decade of life and during the fourth decade of life in smokers.

Symptoms of alpha1-antitrypsin (AAT) deficiency emphysema are limited to the respiratory system. Dyspnoea is the symptom that eventually dominates alpha1-antitrypsin deficiency. Similar to other forms of emphysema, the dyspnoea of alpha1-antitrypsin deficiency is initially evident only with strenuous exertion. Over several years, it eventually limits even mild activities.
The serum levels of some of the common genotypes are:
•PiMM: 100% (normal)
•PiMS: 80% of normal serum level of A1AT
•PiSS: 60% of normal serum level of A1AT
•PiMZ: 60% of normal serum level of A1AT, mild deficiency
•PiSZ: 40% of normal serum level of A1AT, moderate deficiency
•PiZZ: 10–15% (severe alpha 1-antitrypsin deficiency)

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.

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.

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.

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).

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.

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

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.

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.

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.

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.

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.

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.