7 - Lung Infections Flashcards
What are the most likely organisms causing the following types of pneumonia:
- Community acquired
- Hospital acquired (>48h post admission)
- Aspiration
- Immunocompromised
Community: S.Pneumoniae, Haemophilus influenzae, Moraxella cattarhalis (atypical include Mycoplasma pneumoniae, S.Aureus, Legionella, Chlamydia)
Hospital: Gram -ve enterobacteria, Staph Aureus, Pseudomonas, Klebsiella
Aspiration: oropharyngeal anaeorobes
Immunocompromised: fungi, viruses (CMV, HSV), Pneumocystis jirovecii, S.Pneumoniae, S.Aureus
What are some signs and symptoms of pneumonia?
Symptoms: fever, rigors, malaise, dyspnea, cough, purulent sputum, pleuritic pain, haemoptysis
Signs: pyrexia, consolidation on CXR, crackles, dull to percussion, reduced expansion, confusion, increased vocal resonance, pleural rub
What investigations should you do if a patient comes in with suspected pneumonia and what will they show?
- O2 sats and ABGs if <92%
- Blood tests: FBC, U+Es, LFTs, CRP
- Blood cultures: if febrile
- CXR: consolidation, cavitation or pleural effusion
- Sputum culture and microscopy
- Check legionella/pneumonococcal urinary antigens
- ?Pleural effusion aspiration and culture
What are some causes of consolidation on a CXR?
- Pneumonia
- TB
- Lung cancer
- Lobar collapse
- Haemorraghe
How is pneumonia severity graded?
CURB-65
Higher mortality with higher score
If someone has a high CURB65 score, what do you need to screen for?
Atypical pneumonia screen by doing serology and urine legionella test
How is pneumonia managed in hospital?
- Antibiotics
- Oxygen to keep sats>94% and PaO2>8
- IV fluids if dehydration, shock or anorexia
- Paracetamol for pleurisy
- VTE prophylaxis
- ITU referral if high CURB65
What antibiotics are generally used for community acquired pneumonia in UHL?
Mild/CURB 1: amoxicillin or doxycycline
Moderate/CURB2: amoxicillin + doxycycline (or clarithromycin) or higher dose doxycycline
Severe/CURB3 upwards: co-amoxiclav and clarithromycin
PROPHYLACTIC DALTEPARIN FOR VTE PREVENTION
What antibiotics are generally used for hospital acquired pneumonia in UHL?
Mild/Moderate: Co-amoxiclav for 5 days or Doxycyline
Severe: Co-amoxiclav higher strength for 5 days or Meropenem
What antibiotics are generally used for aspiration pneumonia in UHL?
Mild/Moderate: co-amoxiclav, if atypical pathogen suspected add doxycycline or clarithromycin
Severe: co-amoxiclav or penicillin
How is pneumonia followed up?
Need a repeat CXR and CRP in 6 weeks to check full resolution and no underlying malignancy/complications
What are some causes of non-resolving pneumonia?
CHAOS
What are some complications of pneumonia?
- Pleural effusion
- Empyema
- Lung abscess
- Respiratory failure
- Septic shock
- Pericarditis/myocarditis
- AFib
- Jaundice secondary to sepsis or antibiotic therapy
What are some features of a lung abscess and how is it treated?
Who should be offered a pneumoncoccal vaccine and which patients is it contraindicated in?
Who are more likely to suffer from the following pneumonias:
- Pneumococcal
- Staphylococcal
- Klebsiella
- Most common. More prevalent in elderly, alcoholics, post-splenectomy, immunosupressed, heart failure
- IVDU, CF, lymphoma, leukaemia. Causes bilateral cavitating bronchopneumonia
- Rare. In elderly, diabetics, alcoholics. Usually drug resistant
How does legionella pneumophilia present and how is it treated?
Presentation: flu like symptoms (malaise, fever, myalgia) then dry cough and dyspnea. Can have D+V, hepatitis, renal failure
Treatment: diagnose with urine antigen/culture and give fluoroquinolone or clarithromycin for 2-3 weeks
Colonises water tanks kept at <60 degrees, e.g hotel air conditioning and hot water systems
What is chlamydophila psittaci and how is it treated?
Causes psittacosis and comes from infected birds (often parrots)
Symptoms: headache, dry cough, fever, lethargy, arthralgia, D+V
Diagnosis: chlamydophila serology
Treatment: Doxycycline or Clarithromycin
What are some causes of viral pneumonia?
- Influenza (most common)
- Swine flu
- Measles
- CMV
- Varicella zoster
Treat with oseltamivir, zanamivir, nebulisers and high flow oxygen
How do you diagnose and treat pneumoncystis pneumonia?
What are the clinical features of respiratory TB?
- Low grade fever
- Drenching night sweats
- Cough that starts dry then becomes purulent
- Haemoptysis
- Fever
- Weight loss
- Malaise
- Clubbing
- Pleural effusion
What are some non-respiratory manifestions of TB?
- Erythema nodosum
- Lymphadenopathy
- Bone/joint tenderness
- Abdominal (colicky pain)
- Meningitis
- Milliary (disseminated)
- Cardiac (pericardial effusion)
- Genitourinary
What are some differentials for haemoptysis?
What are some risk factors for TB?
- Past history of TB
- Known history of TB contact
- Born in a coutry with high TB incidence
- Foreign travel to area with high TB levels
- Immunosuppression e.g IVDU, HIV, Diabetes, low BMI, dialysis, alcoholism
How is latent TB diagnosed?
- Tuberculin skin testing Mantoux
- Interferon gamma release assays
How is active TB diagnosed?
- CXR
- Sputum smear (Ziehl-Neelsen Acid fast)
- Sputum culture
- NAAT (rapid diagnosis in 8 hrs and can detect drug resistance)
If TB is diagnosed, what further testing is offered?
HIV