Flashcards in Chest infections Deck (26):
Common organisms causing pneumonia (7)
Streptococcus pneumoniae: (80%) high fever, rapid onset, herpes labialis (cold sore)
Haemophilus influenza: Common in COPD
Staphylococcus aureus: Following influenza virus
Mycoplasma pneumoniae: Atypical, dry cough atypical chest signs/ x-rays. Autoimmune haemolytic anaemia and erythema multiforme may be seen.
Legionella pneumophilia: Atypical, Hyponatraemia, lymphopenia common
Klebsiella pneumoniae: Common in alcoholics
Pneumocystis jiroveci: Typically seen in patients with HIV. Presents with a dry cough, exercise-induced desaturations and the absence of chest signs
Upper zone fibrosis causes (7)
Extrinsic allergic alveolitis/hypersensitivity pneumotits
coal worker's pneumoconiosis, silicosis
ankylosing spondylitis (rare)
Lower zones fibrosis causes (4)
idiopathic pulmonary fibrosis
most connective tissue disorders (except ankylosing spondylitis)
drug-induced: amiodarone, bleomycin, methotrexate
What is hypersensitivity pneumonitis?
Inhalation of organic dust resulting in inflammation of the alveoli
Signs and symptoms of hypersensitivity pneumonitis
Clubbing (Chronic HP)
Bibasalar or diffuse crackles
Risk factors for hypersensitivity pneumonitis (6)
Acid anhydride (paint finisher)
Metal working fluid
Nitrofurantoin, methotrexate, roxithromycin, and rituximab
Treatment for hypersensitivity pneumonitis
prednisolone: 0.5 to 1 mg/kg/day orally, taper dose by 5-10 mg/day every other day for 6 weeks
If chronic: prednisolone: 10 mg orally once daily on alternate days
What is pneumoconioses? (silicosis and coal workers' pneumoconiosis)
Interstitial lung disease due to inhalation of metals or minerals.
Interstitium is a collection of support tissues within the lung that includes the alveolar epithelium, pulmonary capillary endothelium, basement membrane, perivascular and perilymphatic tissues.
Pathophysiology of Silicosis
Silica which accesses the alveoli is ingested by macrophages, causing cytolysis of macrophages
Results in further inflammatory response
Signs and symptoms of pneumoconioses
Dyspnoea on exertion
Normal chest examination (at early stage)
Main diagnosis is history (ie exposure to silica, coal, beryllium)
Investigations for pneumoconioses
CXR: progressive upper zone non-calcified, small, rounded opacities, 'egg shell calcification' specific for silicosis
Spirometry: May show restrictive changes, obstructive or mixed.
Restrictive patterns on spirometry test
reduced FVC, normal FEV1/FVC ratio, reduced slow vital capacity, reduced total lung capacity (TLC), reduced lung diffusion capacity testing (DLCO).
Obstructive patterns in spirometry test
reduced FEV1, reduced FEV1/FVC ratio, increased residual volume/TLC ratio
Treatment for chronic pneumoconioses
Stop smoking, remove from occupational exposure
Prednisolone 40-70 mg initially
If hypoxic: oxygen supplement
If COPD: Bronchodilator
If end stage respiratory failure: Refer for lung transplant
What is sarcoidosis?
a chronic granulomatous disorder. Typically affects lungs and lymph nodes in >90% of cases. Can affect any part of the body
Collection of lymphocytes and macrophages
Sarcoidosis signs and symptoms
Auscultation: Rhonchi (low pitch rattling noise resembling snoring)
Enlarged and non tender lymph nodes (mainly cervical and sub-mandibular)
Sarcoidosis risk factor
Investigation to order if sarcoidosis suspected
CXR: Hilar and/or paratracheal adenopathy
FBC: Anaemia?, leukopenia?
Serum Ca: Hypercalcaemia
Skin biopsy: non-caseating granulomas
Acute treatment of sarcoidosis
Unable to take oral: IV methylprednisolone (40 mg every 6 hrs)
Able to take oral: Prednisolone (40 mg OD)
Chronic treatment of sarcoidosis
Symptomatic Stage I with progressive adenopathy: Prednisolone 20-40 for 1-3 months, Inhaled budenoside
Symptomatic stage II, III, IV: Same as stage I,
DMARD (methotrexate, azathioprine, hydroxychloroquine)
Infectious disease caused by Mycobacterium tuberculosis. In many cases, M tuberculosis becomes dormant before it progresses to active TB
Tuberculosis. Signs and Symptoms
Investigations to order if TB suspected (5)
1. CXR: Fibronodular opacities in upper lobes with/without cavitation
Can be middle/lower lobes or in pleural effusion (atypical)
2. Sputum Acid Fast Bacilli smear (AFB smear): 3 tests 8 hours apart
3. Sputum culture: positive; no growth; or other mycobacteria
While on treatment patients should have sputum cultures done until two consecutive negative tests
4. FBC: Raised WBC in particular monocyte and eosinophil count.
5. Nucleic acid amplification test (NAAT): Positive for M tuberculosis
6. HIV test: HIV and Pulmonary TB is an AIDs defining diagnosis
Treatment for active TB in HIV negative, non pregnant.
Initial Phase (1st 2 months): Rifampin + Isoniazid + Pyrazinamide + Ethambutol (stopped if isolate sensitive to RIF and INH)
Continuous phase: Isoniazid + Rifampin for 4 months. 7 months if there are cavities on CXR.