Respiratory infections Flashcards
Allergic bronchopulmonary aspergillosis (ABPA)
a) Presentation
b) Investigation results
c) Management
d) Differentiated from aspergilloma and invasive aspergillosis how?
e) Differentiated from EGPA how?
a) - Chronic wheezy breathlessness (asthma), bronchiectasis, haemoptysis
- Commonly cough up mucus plugs, these may be in the shape of the bronchial tree
b) - Bloods - eosinophilia, raised IgE, aspergillus precipitins
- Rule out via skin prick testing for aspergillus fumigatus (may be false positive)
- CXR - may show upper/middle lobe infiltrates
- HRCT - proximal bronchiectasis
c) - Avoid exposure to compost and to damp
- Steroids until symptoms resolve
- Antifungals added for steroid-sparing effect
- Monitor IgE (clinical response) and LFTs (due to antifungal hepatotoxicity)
d) Aspergilloma:
- solid lesion on CXR with surround halo of air- ‘crescent sign’ (vs ABPA which cause proximal bronchiectasis)
- common in previous TB infection
- haemoptysis (vs ABPA which causes SOB/wheeze)
- Rx: surgical resection (if not candidates for surgery, try antifungals like itraconazole)
Invasive aspergillosis
- negative for Aspergillus IgE and IgG
(requires Galactomannan test)
- Signs of sepsis and consolidation on CXR
- Occurs only in immunosuppressed patients. Those with diabetes/alcohol abuse may get semi-invasive aspergillosis
Galactomannan test
(n.b. not detected on skin prick/precipitin tests)
e) - EGPA does not have raised IgE or aspergillus precipitins
- ABPA does not have ANCA, sinusitis or other vasculitic involvement (e.g. RPGN, neuropathy)
Mycoplasma pneumonia
a) Presentation
b) Findings on investigations
c) Management and why
a) - Fever, headache, myalgia, muscle tenderness, dry cough
- Often in previously fit young adults
- Risk higher in those living in close quarters (e.g. barracks)
- High frequency of extrapulmonary complications (e.g. pericarditis, myocarditis, rash*, aseptic meningitis, encephalitis, haemolytic anaemia)
*Erythema multiforme or viral exanthem
b) - Bronchopneumonia on CXR (increased interstitial markings)
- 50% have raised cold agglutinins ?haemolytic anaemia
c) Macrolide
(note: penicillins will not work as mycoplasma doesn’t have a cell wall)
TB
a) When and how to treat latent TB
b) First pulmonary lesion - name
c) What is a Ranke complex?
d) Pleural TB diagnosis and management
e) Miliary TB diagnosis
a) - If recent contact with suspected infected persons and positive skin test/IGRA
- Rifampicin + isoniazid for 3 months (or isoniazid alone for 6 months)
b) Ghon focus
c) Ranke complex = Ghon focus + lymphangitis + ispilateral calcified LN
d) Pleural tissue biopsy (US-guided)
Treatment as for pulmonary TB: anti-TB medication for 6 months (4 months RIPE, 2 months R&I)
e) Bronchoscopy + lavage
Treatment as for pulmonary TB
MDR-TB
a) Define MDR and XDR
b) Risk factors
c) Management
a) MDR - resistance to rifampicin and isoniazid
XDR - resistance to the above + fluoroquinolones + injectable alternatives (e.g. linezolid, bedaquilline, amikacin)
b) Poor compliance, HIV infection, contact with TB resistant infection, previous TB treatment
c) 1st line generally fluoroquinolones, linezolid, bedaquilline (+ amikacin)
Chlamydia psittaci
a) Treatment
b) Abnormality on blood
a) Macrolides
b) LFT derangement in 50%
Antibodies diagnostic
CURB-65
a) Features
b) Management of each score
c) Prognosis: approx 30 day mortality
a) Confusion, urea >7, RR >30, BP <90/60, age >65
b) CURB 0-1 = outpatient preferred, oral ABx
CURB 2 = inpatient admission (consider adding macrolide)
CURB 3+ = HDU/ICU considered
c) 0 = <1%
1 = 3%
2 = 10%
3 = 20%
4 = 40%
5 = 60%
Histoplasmosis
a) What is it?
b) Who is at risk?
c) Presentation
d) CXR/CT findings
e) Diagnosis
f) Treatment
a) - Fungal infection, caused by histoplasma capsulatum
b) - Travellers to endemic areas (e.g. North America)
- Workers with bats/ infected birds
- AIDS (risk of invasive histoplasmosis if CD4 <150)
- Chronic lung disease (risk of chronic histoplasmosis)
c) - LRTI
- Substernal pain
- Dysphagia due to oesophageal compression
d) - Patchy infiltrates and mediastinal widening on CXR
- Histoplasmoma - “target lesions”
e) Histoplasma culture (sputum, blood, urine)
- Yeast on culture
f) Antifungal meds
e.g. amphotericin B (AmBisome), itraconazole
Bronchiectasis
a) Tests to identify cause
b) Empirical management of LRTI
a) - Immunoglobulins - raised IgE (ABPA), IgA/IgM deficiency
- If sinusitis/infertility - ciliary function tests
- If young/strong suspicion - CF sweat test
- Bronchoscopy may be used to rule out obstructive cause in localised bronchiectasis
b) - Send sputum sample
- Amoxicillin 500mg TDS or 1g TDS for 14 days (most common organism is haemophilus influenzae)
- If grow pseudomonas - PO ciprofloxacin 14 days, or if very unwell - 14 days of IV ABx (e.g. ceftazidime, meropenem, tazocin). Can also consider nebulised colistin. If resistant to any of the above, add IV gentamicin or tobramycin
Cavitating pneumonias
a) 2 main types and their differentiating features
a) Staph aureus:
- Often follows influenza infection
- Bilateral lower lobe pneumonia
- Common in immunosuppressed patients (e.g. CF, cancer), those with a central line, and IVDUs
b) Klebsiella:
- Common in alcoholics/ immunosuppressed
- Upper lobes
Pneumonias
a) Which pathogen leads to HSV reactivation in 40%
b) Causes of early HAP/VAP
c) Causes of later HAP/VAP
a) Strep pneumoniae
b) As for CAP - strep, haemophilus, also MSSA
c) Pseudomonas, klebsiella, MSRA
Infections in CF:
a) 2 common gram negative rods
a) - Pseudomonas
- Cepacia
Legionnaires disease
a) Risk factors
b) Clinical features
c) Diagnosis
d) Management
a) - Holidays to Spain
- Contaminated air conditioning/showers - spas, hotels, resorts
b) - Pneumonia (uni/multilobar, sometimes with effusions)
- Confusion
- D&V
- Lymphopenia
- Hypoalbuminaemia and raised ALT/GGT
- Hyponatraemia
- Renal involvement - haematoproteinuria
c) - Urine antigen
- Note: legionella bacteria doesn’t gram stain
d) - Macrolides or quinolone
- Add rifampicin in severe infection
- High mortality - 15-30%, involve ICU
Pneumocystis pneumonia (PCP)
a) Prophylaxis
b) Management
c) Always suspect when
d) Diagnosis
a) If CD4 count <200:
- PO co-trimoxazole
- If intolerant, pentamidine nebulisers
b) - IV co-trimoxazole + macrolide
- If intolerant to septrin, primaquine and macrolide
- If pO2 <9.3, add steroids
c) - HIV positive or known risk factors for HIV eg IVDU, MSM, endemic area
- Exertional hypoxia in young person
d) Sputum samples - often low yield
BAL and Transbronchial biopsy - much better yield
Chronic eosinophilic pneumonia
a) Risk factors
b) Clinical features
c) Diagnosis
d) Treatment
a) Female, asthmatic, vasculitis
b) - Fever, cough, SOB, wheeze, weight loss
- No clubbing
c) - Pulmonary eosinophilia (sputum or lavage), whereas serum eosinophils may be normal
- Serum IgG and ESR raised
- CXR shows peripheral infiltrates
d) Steroids
Parapneumonic effusion
a) Indications for drain
a) Empyema:
- Frank pus on aspiration
- pH <7.2
- Glucose <2.2
- LDH >1,000
- Cultured organism
