Respiratory JC014: Fever And Purulent Sputum: Influenza, Pneumonia: Common Organisms And Anti-microbial Agents For Pneumonia Flashcards

Question

Amantadine / Rimantadine

Answer 1

- Interfere with viral ***uncoating inside cells - Effective ONLY against ***influenza A - Not useful in treating Avian flu - Severe toxic effects (mainly neurological) - Rapid emergence of drug ***resistance

Answer 2

Interfere with release of progeny influenza virus from infected host cells —> Stop spread of infection in respiratory tract - Effective against influenza ***A+B - Active when give asap (within ***48 hours) - Oseltamivir (Tamiflu: Oral), Zanamivir (Relenza: Inhaled)

Answer 3

- Pathological dilatation of bronchi - Chronic destruction of bronchi (***colonised by bacteria) - Generalised / Localised Causes: 1. ***Mostly idiopathic (need to look out for secondary causes before concluding idiopathic) 2. Secondary causes - ***Post-infection - ***Post-TB - ***Immunodeficiency - ***Autoimmune (e.g. RA) - Aspiration - Primary ciliary dyskinesia - Cystic fibrosis Symptoms: 1. ***Chronic sputum production + cough 2. Episodes of infective ***exacerbations (∵ retention of secretions in mucosal surface since cannot be cleared —> overgrowth of bacteria) 3. ***Haemoptysis: usually infective 4. Dyspnea, Chest pain, Weight loss, Fatigue Signs: 1. Cachexic 2. ***Clubbing 3. ***Coarse crackles, ***↓ Breath sound, ***Dull 4. Associated COPD 5. ***Respiratory failure 6. Progressive lung damage 7. ***Lung abscesses 8. ***Empyema 9. Brain abscess 10. Other complications

Answer 4

1. CXR - may be normal / ***tramline shadows (bronchi do not taper, parallel), ***signet ring sign (prominently dilated airway compared to its accompanying pulmonary vessels) 2. ***HRCT thorax (Gold standard) 3. ***Immunoglobulins - look for secondary cause (e.g. deficiency can cause repeated infections) 4. ***Auto-Ab - look for secondary cause (e.g. RA) 5. Sputum culture, ***AFB 6. Barium studies / 24 hour esophageal pH monitoring - repeated reflux / aspiration 7. Ciliary / Sperm analysis - ***Primary ciliary dyskinesia (congenital: impaired ciliary function) 8. Neutrophil functions (rare) 9. Sweat test (measure amount of Cl in sweat: very high Cl —> cystic fibrosis) - ***Cystic fibrosis

Answer 5

Acute exacerbations: - Haemophilus influenzae - Staphylococcus aureus - ***Pseudomonas aeruginosa (if long-standing) (poor prognosis) 1. Anti-pseudomonal antiobiotics - ***Extended spectrum penicillins (e.g. ***Piperacillin-Tazobactam) - ***3rd gen Cephalosporin (e.g. ***Ceftazidime) - ***Carbapenems (e.g. ***Meropenem) - Aminoglycoside (e.g. Amikacin) (Inhaled form: if colonisation by Pseudomonas + frequent exacerbation, SE: Bronchospasm, Ototoxicity, Vestibular toxicity, Nephrotoxicity (SpC Medicine)) - Fluoroquinolone (e.g. Levofloxacin) —> Only Orally available (others IV) 2. ***ICS +/- LABA - in overlapped airflow obstructive disease (- not routine use in bronchiectasis only (SpC Medicine) (支氣管擴張不用再擴張氣管)) 3. Long-term macrolides - ***Immunomodulating rather than antibiotic effect - Azithromycin, Erythromycin - watch out for ***prolonged QTc, ***sensorineural hearing impairment (- for recurrent exacerbation (SpC Medicine)) 4. ***Postural drainage - use gravity to drain retained mucus 5. Chest physiotherapy 6. Surgery - for localised bronchiectasis - very limited disease 7. Lung transplantation (SpC Medicine) 8. ***Vaccination - Streptococcus pneumoniae - Influenza 9. Pulmonary rehabilitation

Answer 6

1. ***Bronchiectasis severity index Parameters - Age - BMI - %FEV1 Predicted - Previous hospital admission (Has the patient been hospitalised with a severe exacerbation in the past 2 years?) - Number of exacerbations in previous year - MMRC Breathlessness Score - Pseudomonas colonisation (chronic colonisation is defined by the isolation of Pseudomonas aeriginosa in sputum culture on >=2 occasions, >=3 months apart in a 1 year period) - Colonisation with other organisms (chronic colonisation is defined by the isolation of potentially pathogenic bacteria in sputum culture on 2 or more occasions, at least 3 months apart in a 1 year period) - Radiological severity Score: - 0-4 points: Mild bronchiectasis - 5-8 points: Moderate bronchiectasis - >=9 points: Severe bronchiectasis 2. ***FACED score - F: FEV1 (>=50% = 0 points, <50% = 2 points) - A: Age (<70 years = 0 points, >=70 years = 2 points) - C: Chronic colonisation (no Pseudomonas = 0 points, presence of Pseudomonas = 1 point) - E: Extension (1-2 lobes affected = 0 points, >2 lobes affected= 1 point) - D: Dyspnea (modified Medical Research Council scale (mMRC)) (0-2 = 0 points, 3-4 = 1 point) Score: - 0-2 points: Mild bronchiectasis - 3-4 points: Moderate bronchiectasis - 5-7 points: Severe bronchiectasis

Answer 7

When 2 structures of similar density are side by side, their borders become undefinable on a plain XR - When a lung lobe is collapsed / consolidated —> density is similar to heart —> if on RML / LUL (where the heart situated in between) —> cannot see border of consolidation vs —> if on RLL / LLL (behind the heart) —> can see border of consolidation clearly Philip Li: - Cannot see heart border: Middle lobe - Cannot see diaphragm: Upper lobe

Answer 8

Suppurative lung lesion with cavity on CXR Cavitating organism causing lung abscess: 1. TB 2. Klebsiella 3. Staphylococci aureus Solitary lung abscess: 1. ***Inadequately treated pneumonia (esp. Staphylococcus aureus, Klebsiella) 2. ***Bronchiectasis-associated 3. Aspiration 4. FB / Tumour obstruction 5. Amoebic, from liver amoebic abscess (in RLL) Multiple lung abscesses: 1. ***Septicaemia (via RV + RA) 2. ***IV catheter (esp. prolonged use for chemotherapy (Hickmann’s catheter) / vascular access for HD) 3. ***IV drug abuse (severe phlebitis) 4. R-sided endocarditis (echo) P/E: 1. Vital signs 2. Respiratory exam 3. Heart complications - Severe phlebitis and evidence of IV drug abuse - Splinter haemorrhage - Murmurs 4. Brain abscess - Conscious level - Focal motor signs - Fundi: haemorrhage / papilloedema (increased ICP) 5. Urinalysis: RBC suggestive of microscopic haematuria Investigations: 1. CXR: Suppurative lung lesion with cavity 2. CBP + D/C 3. LRFT 4. Blood culture 5. Sputum for Gram stain, C/S 6. Sputum for ova and parasite - whenever a parasitic cause for lung abscess is suspected 7. FOB 8. Echocardiogram (despite no murmur, vegetation may still be present in heart) 9. Full septic workup: HBV, HCV, HIV, MRI brain as indicated Treatment: 1. High-dose IV empirical antibiotics - Depending on scenarios and cultures, e.g. aspiration, bronchiectatic / parasitic abscess - Prolonged duration (4-6 weeks) - No need of percutaneous drainage in most cases (because natural drainage through airway)

Answer 9

1. Addiction 2. Direct abuse drug toxicity (e.g. morphine overdose) 3. Phlebitis + thrombosis 4. Multiple lung abscesses 5. Other organ abscesses - Brain abscess —> MRI brain - Liver abscess (pathogens not completely filtered off in lung but carried to systemic circulation) 6. R-sided infective endocarditis (S. auerus) 7. HBV / HCV infections 8. HIV infections 9. Tetanus

Answer 10

- Pneumocystis jirovecii (previously P. carinii) - AIDS-defining illness —> Lymphopenia —> ***Reversed CD4:CD8 ratio (normal 1-4 (web)) —> ***CD4 <200 very likely cause opportunistic infections CXR: - ***Bilateral Diffuse ground glass opacity (Pathognomonic) (DDx: Viral infection e.g. CMV (SpC Revision)) - Lymphopenia Diagnosis: - ***Induced sputum / BAL fluid: cysts of P. jirovecii in lung tissue, stained with ***Silver stain - ***NPA for PCR - Cannot be cultured - Lung biopsy not done since too invasive Treatment: 1. ***21 days ***Co-trimoxazole (Septrin) - PO/IV (= IV Pentamidine) - CI in G6PD: must check status 2. ***Adjunctive steroid for severe PCP with PaO2 <9kP - Cytokine storm may happen after killing of microbes with cotrimoxazole —> give adjunctive steroid to damp down severe cytokine storm / inflammatory response Prophylaxis: 1. Primary: CD4 <200 2. Secondary: with history of PCP - Co-trimoxazole in prophylactic dose (unless HAART renders CD4 >200 >3m)

Answer 11

Inheritance: - Autosomal recessive mainly Clinical features: 1. Pulmonary - Chronic productive cough - Recurrent pneumonia - Recurrent rhinosinusitis 2. Eustachian tube - Otitis media 3. CNS - Headache, fatigue 4. Fertility - Immotile sperm - Ectopic pregnancy Associated symptoms: - Situs inversus - Kartagener syndrome: Triad of Situs inversus, Chronic sinusitis, Bronchiectasis - Transposition of great vessels, other cardiac abnormalities - Pyloric stenosis - Epispadias Diagnosis: - ***PICADAR score (Prerequisite question: Does patient have daily wet cough that started in early childhood?) - ***Ciliary brush - ***Nasal NO (Very low / absent) Management: 1. ***Antibiotic for infections 2. Airway clearance therapy - ***Oscillating PEP device, Chest physiotherapy - ***Nasal washing - Hypertonic saline 3. Vitamin D (for chronic lung disease) 4. Vaccination

Answer 12

1. Lymphangitis carcinomatosis 2. Miliary TB 3. Silicosis 4. Sarcoidosis 5. Pulmonary haemosiderosis

Answer 13

Ground glass: - Increased attenuation of the lung with preserved bronchial and vascular markings (web) For patients on immunosuppressants: 1. Pneumocystis jirovecii pneumonia 2. Viral infection (e.g. CMV) Self notes: 1. Atypical pneumonia (e.g. Mycoplasma pneumoniae, Chlamydophila pneumoniae, Legionella pneumophila) 2. Interstitial lung disease (Pulmonary fibrosis) 3. Pulmonary edema

Answer 14

TB: 1. ZN stain 2. AFB smear 3. PCR 4. Culture PCP: 1. Silver stain 2. Cysts of PCP 3. PCR