CURB Pneumonia Severity Score:
– 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) Based on the CURB Pneumonia Severity Score, the patient has severe pneumonia. According to the 2009 Centres for Medicare and Medicaid Services (CMS) and Joint Commission consensus guidelines, inpatient treatment of pneumonia should be given within four hours of hospital admission (or in the emergency department if this is where the patient initially presented) and should consist of the following antibiotic regimens, which are also in accordance with IDSA/ATS guidelines. For non-intensive care unit (ICU) patients:
Beta-lactam (intravenous [IV] or intramuscular [IM] administration) plus macrolide (IV or oral [PO])
Beta-lactam (IV or IM) plus doxycycline (IV or PO)
Antipneumococcal quinolone monotherapy (IV or IM)

If the patient is younger than 65 years with no risk factors for drug-resistant organisms, administer macrolide monotherapy (IV or PO)

For ICU patients:
IV beta-lactam plus IV macrolide
IV beta-lactam plus IV antipneumococcal quinolone

If the patient has a documented beta-lactam allergy, administer IV antipneumococcal quinolone plus IV aztreonam.

The most suitable antibiotic therapy for this patient is therefore Intravenous co-amoxiclav + clarithromycin.

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

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.

Infection with Klebsiella organisms occurs in the lungs, where they cause destructive changes. Necrosis, inflammation, and haemorrhage occur within lung tissue, sometimes producing a thick, bloody, mucoid sputum described as currant jelly sputum.
The illness typically affects middle-aged and older men with debilitating diseases such as alcoholism, diabetes, or chronic bronchopulmonary disease. An increased tendency exists toward abscess formation, cavitation, empyema, and pleural adhesions.

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.

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.

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.

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.

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.

Asthma is a condition characterized by airway hyperresponsiveness, which results in reversible increases in bronchial smooth muscle tone, and variable amounts of inflammation of the bronchial mucosa.
During an acute asthma attack, the already inflamed airways narrow further due to bronchospasm, which leads to increased airway resistance. Because of the increased smooth muscle tone during an asthma attack, the airways also tend to close at abnormally high lung volumes, trapping air behind occluded or narrowed small airways. Thus the acute asthmatic will breathe at high lung volumes, his functional residual capacity will be elevated, and he will inspire close to total lung capacity. The accessory muscles of respiration are often used to maintain the lungs in a hyperinflated state.

During episodes of acute asthma, pulmonary function tests reveal an obstructive pattern. This includes a decrease in the rate of maximal expiratory air flow (a decrease in FEV1 and the FEV1/FVC ratio) due to the increased resistance, and a reduction in forced vital capacity (FVC) correlating with the level of hyperinflation of the lungs. Because these patients breathe at such high lung volumes (near the top of the pressure-volume curve, where lung compliance greatly decreases), they must exert significant effort to create an extremely negative pleural pressure, and consequently fatigue easily. Overinflation also reduces the curvature of the diaphragm, making it less efficient in generating further negative pleural pressure.

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.

Churg-Strauss disease (CSD) is one of three important fibrinoid, necrotizing, inflammatory leukocytoclastic systemic small-vessel vasculitides that are associated with antineutrophil cytoplasm antibodies (ANCAs).
The first (prodromal) phase of Churg-Strauss disease (CSD) consists of asthma usually in association with other typical allergic features, which may include eosinophilia. During the second phase, the eosinophilia is characteristic (see below) and ANCAs with perinuclear staining pattern (pANCAs) are detected. The treatment would therefore be different from asthma. For most patients, especially those patients with evidence of active vasculitis, treatment with corticosteroids and immunosuppressive agents (cyclophosphamide) is considered first-line therapy

Postmenopausal oestrogen therapy and hormone therapy are associated with an increased risk of thromboembolism. The relative risk seems to be even greater if the treated population has pre-existing risk factors for thromboembolism, such as obesity, immobilization, and fracture. Cor pulmonale can occur secondary to small recurrent pulmonary embolisms. Pneumonias and bronchiectasis usually present with purulent sputum, and in case of carcinoma there may be other associated symptoms like weight loss, etc.

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.

Acute exacerbations of chronic obstructive pulmonary disease (COPD) are immediately treated with inhaled beta2 agonists and inhaled anticholinergics, followed by antibiotics (if indicated) and systemic corticosteroids. Methylxanthine therapy may be considered in patients who do not respond to other bronchodilators.
High flow oxygen would worsen his symptoms. Usually titrated oxygen (88 to 92 %) is given in such patients to avoid the risk of hyperoxic hypercarbia in which increasing oxygen saturation in a chronic carbon dioxide retainer can inadvertently lead to respiratory acidosis and death.

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.

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.

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.

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.

Lofgren’s syndrome is an acute form of sarcoidosis characterized by erythema nodosum, bilateral hilar lymphadenopathy (BHL), and polyarthralgia or polyarthritis. Other symptoms include anterior uveitis, fever, ankle periarthritis, and pulmonary involvement.

Löfgren syndrome is usually an acute disease with an excellent prognosis, typically resolving spontaneously from 6-8 weeks to up to 2 years after onset. Pulmonologists, ophthalmologists, and rheumatologists often define this syndrome differently, describing varying combinations of arthritis, arthralgia, uveitis, erythema nodosum, hilar adenopathy, and/or other clinical findings.

Cystic fibrosis (CF) is a multisystemic, autosomal recessive disorder that predominantly affects infants, children, and young adults. CF is the most common life-limiting genetic disorder in whites, with an incidence of 1 case per 3200-3300 new-borns in the United States.

People with CF can have a variety of symptoms, including:
Very salty-tasting skin
Persistent coughing, at times with phlegm
Frequent lung infections including pneumonia or bronchitis
Wheezing or shortness of breath
Poor growth or weight gain in spite of a good appetite
Frequent greasy, bulky stools or difficulty with bowel movements
Male infertility

Signs of bronchiectasis include the tubular shadows; tram tracks, or horizontally oriented bronchi; and the signet-ring sign, which is a vertically oriented bronchus with a luminal airway diameter that is 1.5 times the diameter of the adjacent pulmonary arterial branch.

Bronchiectasis is characterized by parallel, thick, line markings radiating from hila (line tracks) in cylindrical bronchiectasis. Ring shadows represent dilated thick-wall bronchi seen in longitudinal section or on-end or dilated bronchi in varicose bronchiectasis.

Pseudomonas aeruginosa is the key bacterial agent of cystic fibrosis (CF) lung infections, and the most important pathogen in progressive and severe CF lung disease. This opportunistic pathogen can grow and proliferate in patients, and exposure can occur in hospitals and other healthcare settings.

Haemophilus influenzae is regularly involved in chronic lung infections and acute exacerbations of CF patients

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.

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.

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.

Cavitating pneumonia is a complication that can occur with a severe necrotizing pneumonia and in some publications it is used synonymously with the latter term. It is a rare complication in both children and adults. Albeit rare, cavitation is most commonly caused by Streptococcus pneumoniae, and less frequently Aspergillus spp., Legionella spp. and Staphylococcus aureus.

In children, cavitation is associated with severe illness, although cases usually resolve without surgical intervention, and long-term follow-up radiography shows clear lungs without pulmonary sequelae
Although the absolute cavitary rate may not be known, according to one series, necrotizing changes were seen in up to 6.6% of adults with pneumococcal pneumonia. Klebsiella pneumoniae is another organism that is known to cause cavitation.

Causative agents:
Mycobacterium tuberculosis
Klebsiella pneumoniae
Streptococcus pneumoniae
Staphylococcus aureus

Enterococcus faecalis was not found to be a causative agent.

Lambert-Eaton myasthenic syndrome (LEMS) is a rare presynaptic disorder of neuromuscular transmission in which release of acetylcholine (ACh) is impaired, causing a unique set of clinical characteristics, which include proximal muscle weakness, depressed tendon reflexes, post-tetanic potentiation, and autonomic changes.

In 40% of patients with LEMS, cancer is present when the weakness begins or is found later. This is usually a small cell lung cancer (SCLC). However, LEMS has also been associated with non-SCLC, lymphosarcoma, malignant thymoma, or carcinoma of the breast, stomach, colon, prostate, bladder, kidney, or gallbladder.

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.

Type I pneumocyte: The cell responsible for the gas (oxygen and carbon dioxide) exchange that takes place in the alveoli. It is a very thin cell stretched over a very large area. This type of cell is susceptible to a large number of toxic insults and cannot replicate itself.
Type II pneumocyte: The cell responsible for the production and secretion of surfactant (the molecule that reduces the surface tension of pulmonary fluids and contributes to the elastic properties of the lungs). The type 2 pneumocyte is a smaller cell that can replicate in the alveoli and will replicate to replace damaged type 1 pneumocytes. Alveolar macrophages are the primary phagocytes of the innate immune system, clearing the air spaces of infectious, toxic, or allergic particles that have evaded the mechanical defences of the respiratory tract, such as the nasal passages, the glottis, and the mucociliary transport system. The main role of goblet cells is to secrete mucus in order to protect the mucous membranes where they are found. Goblet cells accomplish this by secreting mucins, large glycoproteins formed mostly by carbohydrates.

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.

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]).