Case 12 - Pneumonia + TB Flashcards
How is pneumonia transmitted?
Aspiration of airborne pathogens or aspiration from stomach contents.
What is community acquired pneumonia?
Which organisms normally lead to CAP?
- Pneumonia not acquired in healthcare setting.
- Streph.pneumoniae
- H.influenza
What is hospital acquired pneumonia?
Pneumonia originating in the hospital with onset >48 hours after admission or within 1 month after discharge.
What ventilation acquired pneumonia?
HAP occurring in patients with mechanical ventilation.
Which micro-organism leads to VAP?
Pseudomonas aeruginosa
What is typical pneumonia?
- Classic symptoms, typical findings on auscultation and percussion.
- Can be cultured using standard methods in the lab
What is atypical pneumonia?
- Less distinct classical symptoms and often remarkable findings on auscultation and percussion
- Cannot be cultured in the lab, needs alternative tools
How is pneumonia classified based on location?
- Bronchopneumonia
- Atypical or interstitial pneumonia
- Lobar pneumonia
How does bronchopneumonia appear on CXR?
Poorly defines patchy infiltrates scattered across lungs
How does interstitial pneumonia appear on CXR?
Diffuse reticular opacity
How does lobar pneumonia appear on CXR?
Extensive opacity restricted to one pulmonary lobe
What are the typical pathogens that lead to pneumonia?
- Streptococcus pneumoniae
- Haemophilus influenzae
- Klebsiella pneumoniae
- Staphylococcus aureus
What are the atypical pathogens that lead to pneumonia?
Legions of psittaci MCQs:
- Legionella pneumophila
- Chlamydia psittaci
- Mycoplasma pneumoniae
- Chlamydia pneumoniae
- Coxiella burnetti
Which organisms are likely to cause HAP?
- Enterobacteria
- Pseudomonas aeruginosa
- Staphylococcus aureus
- Streptococcus pneumoniae
Who is more likely to get pneumocystis jirovecii pneumonia?
Immunocompromised and HIV patients
What type of pathogen is pneumocystis jirovecii?
Fungal
How do people with pneumocystis jirovecii pneumonia present?
- Dry cough without sputum
- SoB on exertion
- Night sweats
How to treat pneumocystis jirovecii pneumonia?
Co-trimoxazole (trimethoprim/sulfamethoxazole)
Which bacteria is the cause of pneumonia in COPD patients?
Haemophilus influenzae
Which bacteria is the cause of pneumonia in cystic fibrosis patients?
- Pseudomonas aeruginosa
- Staphylococcus aureus
How is legionella pneumophila (Legionnaires’ disease) spread?
What can it also cause?
- Infected water supplies or air conditioning units
- Hyponatreamia due to SIADH
How might an exam question about legionella pneumophila (Legionnaires’ disease) present?
Recently had a cheap hotel holiday and presents with hyponatraemia.
Who is at more risk of chlamydia psittaci?
- Typical exam question
- Typically contracted from contact with infected birds
- Patient is parrot owner
Who is at more risk of coxiella burnetii?
- Typical exam question
- Exposure to animals and their bodily fluids.
- Farmer with a flu like illness
How might chlamydophila pneumoniae present?
School aged child with a mild to moderate chronic pneumonia and wheeze
What sign might be present for mycoplasma pneumoniae?
Erythema multiforme rash - “target lesions” formed by pink rings with pale centres.
How might mycoplasma pneumoniae present?
Young patient has neurological symptoms
What are the risk factors for CAP?
- Very old/young people
- Cystic fibrosis
- COPD, HF, bronchial asthma
- Immunosuppressed: HIV, DM
- Smoking
What are the risk factors for HAP?
- ICU stay
- Mechanical ventilation
- COPD, CF
- Abdominal surgery
- Vomiting/aspiration
What are the symptoms of pneumonia?
- Severe malaise
- High fever and rigors
- Productive cough with purulent sputum (rusty with strep pneumonia)
- Tachypnoea
- Dyspnoea
- Pleuritic chest pain
- Pain projecting to the abdomen and epigastric region
What are the signs of pneumonia?
- Coarse crackles, bronchial, and decreased breath sounds
- Enhanced bronchophony, egophony, and increased tactile vocal fremitus
- Dullness on percussion over affected sites
How to test for streptococcus pneumoniae and legionella antigen?
Send a urine sample for antigen testing
What investigations to do in pneumonia?
- FBC: WCC raised in acute infection
- CRP levels
- Lactate: sepsis, shock
- Urinary antigen testing
- U+Es
- Sputum culture
- Blood culture
How does typical pneumonia appears on CXR?
Lobar pneumonia
How does atypical pneumonia appears on CXR?
Interstitial pneumonia
In which CXR (effusion or consolidation) are margins of opacification are not clear?
Consolidation
In which CXR (effusion or consolidation) are opacifications dense and there are no markings visible in the lung field?
Effusions
In which CXR (effusion or consolidation) is the diaphragm, angles more visible?
Effusions
What is the CURB 65 score?
Confusion Urea > 7 mmol/L Respiratory rate ≥ 30/min Blood pressure: systolic BP ≤ 90 mm Hg or diastolic BP ≤ 60 mm Hg Age ≥ 65 years
What do the results of CURB 65 mean?
- Score 0-1: The patient may be treated as an outpatient.
- Score 2: Hospitalisation is indicated.
- Score 3-5: Admit to ICU
What is the mortality risk with each CURB 65 score?
- Score 0-1: <3%
- Score 2: 3-15%
- Score 3-5: >15%
How soon after admission into hospital for pneumonia should someone receive antibiotics?
4 hours
How is CAP treated?
- Low severity (0 or 1): oral amoxicillin
- Moderate (score 2) – oral amoxicillin and clarithromycin
- Severe (score 3 to 5) - IV co-amoxiclav + clarithromycin
How is HAP treated?
- Non severe signs or symptoms – Co-amoxiclav
- Severe signs or symptoms (or high risk of resistance) – IV Piperacillin with tazobactam
What antibiotics should be considered for pseudomonas?
Tazocin and quinolones
What antibiotics should be considered for legionella pneumophilia?
Levofloxacin and rifampicin
What are the complications of pneumonia?
- Para-pneumonic exudative pleural effusion
- Para-pneumonic pleuritis
- Empyema
- Lung abscess
- Metastatic infections
- Pulmonary VTE
- Sepsis
- Respiratory failure, ARDS
What is the follow up after pneumonia?
- 1 week: fever should have resolved
- 4 weeks: chest pain and sputum production should have reduced
- 6 weeks: cough and breathlessness should have substantially reduced
- 3 months: most symptoms should have resolved but fatigue may still be present
- 6 months: most people will feel back to normal.
How soon after should a CXR be done to ensure opacity has cleared?
6 weeks
What are the 2 types of bacterias that lead to TB?
- Mycobactrium tuberculosis: 95% of cases
- Mycobacterium bovis (cow’s milk)
How is TB transmitted?
- Inhalation of infected droplets through the air
- Infected milk (M. bovis)
What is: 1- Active TB 2- Latent TB 3- Secondary TB 4- Extra-pulmonary TB
1- Active infection in various areas within the body
2- Person is infected with TB but does not have any symptoms of disease and is not infectious.
3- TB reactivates again with symptoms and they are contagious.
4- Immune system is unable to control the disease this causes disseminated TB
What are the common sites of extra-pulmonary TB?
What is miliary TB?
Bones, pleura, lymphatic system (known as miliary TB and is the most dangerous spread of TB), liver and urinary.
What is the chance of getting primary TB if exposed to an infectious cause?
30%
What are the symptoms of active TB?
- Fever,
- Weight loss
- Night sweats
- Fatigue
- Lymphadenopathy
- Dyspnea
- Productive cough (possibly haemoptysis) lasting > 3 weeks
- Pleuritic pain and bone pain
What can be seen on a CXR for primary TB?
- Patchy consolidation
- Pleural effusions
- Hilar lymphadenopathy
What can be seen on a CXR for reactivated TB?
- Patchy or nodular consolidation with cavitation (gas filled spaces in the lungs) typically in the upper zones
What stain do you use to identify TB on sputum microscopy?
- What colour does it stain?
- Acid fast stain (Zeihl-Neelsen)
- Stains red
How is the tuberculin skin test (mantoux test) used?
- A test to assess for latent TB, in which 5 units of purified protein derivative tuberculin is injected intradermally.
- The skin reaction should be read 48–72 hours
- The test only becomes positive 6–8 weeks after infection.
- A healthy individual without any risk factors for TB infection who has an induration smaller than 15 mm is considered negative for TB
How is the IGRA (interferon gamma release assay) used in the assessment of TB?
- An ELISA test that measures the level of interferon-γ expressed by T cells after coming into contact with Mycobacterium tuberculosis.
- Used to diagnose latent tuberculosis infection in at-risk populations.
- Elevated interferon-γ levels indicate a positive result.
- In contrast to tuberculin skin testing, there are no false-positive results with IGRA in patients who received the bacillus Calmette-Guérin (BCG) vaccine.
When is IGRA test used?
Patients that do not have features of active TB but do have a positive Mantoux test to confirm a diagnosis of latent TB.
What is the treatment for active TB?
- Initiation phase: 2 months of isoniazid + rifampin + pyrazinamide + ethambutol
- Continuation phase: 4 months of isoniazid + rifampin
What is the treatment for latent TB for those at risk of reactivation?
- Isoniazid and rifampicin for 3 months OR
- Isoniazid for 6 months
What are the side effects of isoniazid?
- Hepatotoxicity (acute hepatitis, chronic liver failure).
- Peripheral polyneuropathy and other symptoms of pyridoxine deficiency (e.g., stomatitis, glossitis, convulsions, and anemia).
What should be prescribed with isoniazid to reduce side effects?
Pyridoxine (vitamin B6)
What are the side effects of rifampicin?
- Hepatotoxicity
- Red or orange body fluids (e.g., urine, tears).
- Thrombocytopenia.
- Flu/GI sx.
What are the side effects of pyrazinamide?
- Hepatotoxicity
- Hyperuricemia
- Arthralgia
- Myopathy
- GI symptoms
What are the side effects of ethambutol?
Retrobulbar neuritis: can lead to blindness
Poly-resistance to TB meds is resistance to….
More than one medication other than both Rifampicin and Isoniazid
Multi-drug resistant TB is resistant to….
Both Rifampicin and Isoniazid
Which bacteria is the more likely cause of pneumonia in alcoholic misusers and elderly?
Klebsiella pneumonia