Week 3/4 - E - Pneumonia (Symptoms, Ix, CURB65, C.A.P, H.A.P, Atypical) and TB (pathogenesis/latent/active/diagnosis/treatment)

Question 1

Pneumonia is an acute lower respiratory tract infection causing inflammation of the lung tissue, primarily the alveoli What are the symptoms of pneumonia and what patients can present in atypical ways?

Answer 1

Symptoms * Fevers * Sweats * Rigors * Cough * Dyspnoea * Confusion * Haemoptosis * Pleuritic pain * Confusion - may be the only sign in the elderly

Question 2

What are the signs of pneumonia?

Answer 2

Cyanosis - could be in resp failure Tachypnoea Chest expansion - reduced Percussion note - dull Auscultation - crackles Also may have hypotension

Question 3

There are different investigations that can be carried out for pneumonia What investigations would usually be carried out in a patient admitted to hospital?

Answer 3

Assess oxygenation - if O2 sats <92%, then ABG Blood tests - FBC, U&Es CXR looking for new infiltrates in the lung or pleural effusion

Question 4

Do not routinely offer microbiological tests to patients with low‑severity community‑acquired pneumonia. When are tests offered and what are the microbiological tests?

Answer 4

For patients with moderate‑ or high‑severity community‑acquired pneumonia: take blood and sputum cultures and consider pneumococcal and legionella urinary antigen tests.

Question 5

When in hospital, usually a CXR is used to assists in the diagnosis of pneumonia in a patient When a clinical diagnosis of community-acquired pneumonia is made in primary care, Use clinical judgement in conjunction with the CRB65 score to inform decisions about whether patients need hospital assessment What score warrants treatment in the community and what score would you advice admittance to hospital?

Answer 5

Patients with a CRB65 score in the community of 0or1 can usually be treated in primary care Patients with a CRB65 score of 2 and above usually require hospital therapy

Question 6

What is the CRB65 (CURB65 if in hospital) criteria What score is mild/moderate and what score is severe? The score helps to determine the patients mortality risk and the treatment therapy is advised based on this

Answer 6

• CONFUSION, NEW (MSQ ≤8/10)
• UREA >7mmol/l (if available)
• RESPIRATORY RATE ≥ 30/minute
• BP <90mmHg (systolic) or ≤60mmHg (diastolic)
• 65 AGE ≥ 65 years

Mild 0-1

Moderate score = 0-2

Severe score = 3-5

Question 7

What are the different causative organisms for mild/moderate community acquired pneumonia and what is the treatment (also if pen allergic)?

Answer 7

Mild/moderate community acquired pneumonia * Strep pneumonia and haemophilus influenza B * Treatment - * Amoxicillin PO?IV * If pen allergic - doxycycline or clarithromycin IV if NBM

Question 8

What are the different causative organisms for severe community acquired pneumonia and what is the treatment (also if pen allergic)?

Answer 8

Severe community acquired pneumonia * Also strep pneumonia and haemophilus influenza B but possible coliforms and atypicals (eg legionella, mycoplasma, chlamydophila, coxiella) * Treatment * IV Co-amoxiclav + PO DOxycycline / IV Clarithromycin if NBM * If pen allergic - IV Levoflaxacin monotherapy

Question 9

What is hospital acquired pneumonia defined as?

Answer 9

Hospital-acquired pneumonia (HAP) is an acute lower respiratory tract infection that is by definition acquired after at least 48 hours of admission to hospital and is not incubating at the time of admission

Question 10

What are the causative organisms in hospital acquired pneumonia?

Answer 10

Caused by pneumococcus, haemophilus and coliforms - legionella can also be hospital acuired

Question 11

What is the treatment of hospital acquired pneumonia, severe and non severe?

Answer 11

Non sevre * Amoxicillin PO * Pen-allergic - Doxycycline Severe * IV amoxicillin + Gentamicin * Pen-allergic - IV CO-trimoxazole + Gentamicin

Question 12

Aspiration pneumonia Which patients is this more common in? What organisms are important to cover in this type?

Answer 12

Aspiration pneumonia results from inhalation of oropharyngeal contents into the lower airways that leads to lung injury and resultant bacterial infection - eg strokes, muscular palsies, decreased consciouness eg intoxicated or post-ictal Important to cover anaerobes in the treatment

Question 13

Which bacteria often seen in aspiration lobar pneumonia in alcoholics causes a red-current jelly type sputum? Which bacteria is the commonest cause of community acquired pneumonia and what type of sputum does it cause?

Answer 13

Klebsiella pneumonia - redcurrent jelly sputum Streptococcus pneumonia (pneumococcus)- causes a rsuty coloured sputum

Question 14

What is the treatment of aspiration pneumonia in non severe and sevre patients?

Answer 14

Non severe - amoxicillin + metronidazole PO Severe - Amox, metron and gent IV If pen allergic -replace amoxicillin with doxycylcine PO or Clarithrmoycin IV

Question 15

Atypical bacterial pneumonia is caused by atypical organisms that are not detectable on Gram stain and cannot be cultured using standard methods. Name the atypical causes of pneumonia How are they treated?

Answer 15

Legionella pneumonia - levoflaxacin (or macrolide eg clarithromycin) All can be treated with tetracycline eg doxycycline or macrolide eg clarithromycin * Mycoplasma pneumonia * Chlamydophila pneumonia * Chlamydophila psittaci * Coxiella pneumonia

Question 16

Legionella pneumonia usually colonizes water tanks kept at less than 60 degrees What is the classicial scenario in when a patient gets this disease? What are the symptoms?

Answer 16

Legionella typically occurs in patient returning from holiday with poor air conditioning Symptoms are typically flu like followed by a dry cough GI disturbance and confusion are common

Question 17

How is legionella pneumonia diagnosed and what is the treatmnet?

Answer 17

Diagnosed with urine antigen test for legionella Treatment - levofloaxacin (fluoroquinolone) or clarithromycin (macrolide)

Question 18

All can be treated with tetracycline eg doxycycline or macrolide eg clarithromycin * Mycoplasma pneumonia * Chlamydophila pneumonia * Chlamydophila psittaci * Coxiella pneumonia Which atypical bacteria causing pneumonia can result in the autoimmune haemolytic anaemia due to the presence of cold agglutins? Describe this disease and its symptoms

Answer 18

MYCOPLASMA PNEUMONIA Cold agglutinin disease (CAD) is a rare autoimmune disease characterized by the presence of high concentrations of circulating cold sensitive antibodies, usually IgM and autoantibodies that are also active at temperatures below 30 °C (86 °F), directed against red blood cells, causing them to agglutinate and undergo lysis Symptoms of CAD include symptoms of anaemia as well as jaundice and dark urine due to excess bilirubin

Question 19

As noted, mycoplasma pneumonia can cause an autoimmune haemolytic anaemia due to the presence of cold agglutins WHen does mycoplasma pneumonia typically occur?

Answer 19

Mycoplasma pneumonia typically occurs in epidemics about every 4 years Symptoms include that of anaemia, dark urine, jaundice and pneuomina

Question 20

How are mycoplasma pneumonia, chlamydophila pneumonia coxiella burnetti diagnosed?

Answer 20

These atypical pneumonias can be diagnosed via serology (bloods taken) howver PCR testing of sputum samples is faster

Question 21

Which atypical pneumonia is linked to sheep and goats? Which atypical pneumonia is linked to parrots and budgies? What type of sputum does it cause?

Answer 21

Coxiella burnetti- sheeps and goats Chlamydophila psittaci - parrots and budgies - mucoid sputum

Question 22

What increases the risk of complications in a patient with pneumonia? What are common complications that can arise due to pneumonia?

Answer 22

The risk of complications in a patient with pneumonia increase in the elderly and those with underying health conditions Common complications Type 1 respiratory failure - V/Q mismatch Pleural effusion - that can beocme infected, can cause pus, can cause an intrapulmonary abscess Sepsis

Question 23

What is tuberculosis and what are the two bacterial pathogens in humans?

Answer 23

Tuberculosis (TB) is a bacterial infectious disease usually caused by Mycobacterium tuberculosis (MTB) bacteria. Tuberculosis generally affects the lungs, but can also affect other parts of the body. Uusally caused by mycobacteriam tuberculosis but can also be caused by mycobacterium bovis

Question 24

Mycobacterium tuberculosis usually stains very weakly or not at all on gram staining If it does stain, what does it show?

Answer 24

If the bacteria does stain, it will show rod shaped gram positive bacilli Pink for gram positive

Question 25

About 90% of those infected with M. tuberculosis have asymptomatic, latent TB infections (sometimes called LTBI),[54] with only a 10% lifetime chance that the latent infection will progress to overt, active tuberculous disease How is tuberculosis transmitted??

Answer 25

Tuberculosis is transmitted via aerosol droplets - therefore the only route of transmission is when people have pulmonary disease (majority of cases have pulmonary disease)

Question 26

Describe the pathogenesis of how mycobacterium tuberculosis infection is able to mutliply and divide

Answer 26

Primary TB infection begins when the mycobacteria reach the alveolar air sacs of the lungs, where they are phagocytosed by the alveolar macrophages. The bacteria survives and multiplies within the macrophage and eventually the proliferating bacilli kill the macrophage and are released. It is at this stage where the immune system will be able to clear the mycobacterium or persistent latent infection / active primaryTB will occur

Question 27

What makes it more likely for the TB inhalation to result in primary tuberculosis?

Answer 27

Latent infection is the most common after infection Primary TB usually only occurs if it is an especially virulent strain or if the patient is immunocompromised

Question 28

Latent TB is infection without disease due to persistent immune system containment How is a granuloma formed in latent TB?

Answer 28

Containment of the TB is dependent on the cellular immune system primarily mediated via Th1 response. Tcells and macrophages form a granuloma consisting of; a centre containing necrotic (caseous) tissue & TB; peripherally containing macrophages and Tlymphocytes

Question 29

What type of hypersensitivity is tuberculosis said to be?

Answer 29

Tuberculosis is said to be type IV hypersensitivity as it is T-cell mediated aka delayed type hypersensitivity T helper cells (specifically Th1 cells) are activated by an antigen presenting cell. When the antigen is presented again in the future, the memory Th1 cells will activate macrophages and cause an inflammatory response. This ultimately can lead to tissue damage

Question 30

TB Granuloma- a centre containing necrotic (caseous) tissue & TB; peripherally containing macrophages and lymphocytes What is the purpose of the granuloma formation in latent TB?

Answer 30

The purpose of the granuloma is to provide immune containment of the TB infection preventing further growth and spread - image above shows a failing granuloma with TB exiting TB – granuloma with central “caseous” necrosis

Question 31

When a granuloma forms in the lung in latent TB, what is it known as?

Answer 31

Ghon Focus → An area of infection and caseous necrosis at the periphery of the lung (a small area of granulomatous infection), beneath the pleura - found in tuberculosis infection.

Question 32

What lobe of the lung does TB primarily effect? Are patients with latent TB infectious? Does latent TBshow on CXR?

Answer 32

TB typically affects the upper lobe of the lungs - doesnt show on CXR in latent infection Patients are not infectious - bacteria contained within granuloma

Question 33

How does latent TB become active infection?

Answer 33

Active TB typically occurs through a process of re-activation or the patient is re-infected with a more virulent strain. Approximately 10% of individuals with latent infection will progress to active disease over their lifetime. Certain factors increase the risk of TB overcoming the immune system to become active

Question 34

What are the risk factors for reaction of TB?

Answer 34

The risk is re-activation greatest within the 2 years following initial acquisition of M tuberculosis are at greatest risk of active infection Also immunosupressed patients eg HIV, steroids, organ transplants Also low socioeconomic status Drug users

Question 35

In patients with latent TB, they are asymptomatic and non-infectious - normal CXR/sputum Specialist screening tests are offered to close contacts of those with pulmonary TB, and other high risk populations What are the screening tests recommended to be carried out in those with latnet TB? (mantoux test, IGRA test)

Answer 35

Mantoux test = tuberculin skin test (TST) * This is a type of tuberculin skin test where tuberculin is injected intradermally. The skin is inspected for signs of a local skin reaction (induration) after 2–3 days Interferon gamma release assay (IGRA) test This is a blood test based on detecting the response of white blood cells to TB antigens. It is less likely to give false positive results compared with a Mantoux test and gives a rapid result.

Question 36

Can either the TST (Mantoux) or IGRA test diagnose or exclude active TB?

Answer 36

NO

Question 37

If a test for latent TB is carried out and comes back positive, how is the person assessed for active disease?

Answer 37

The person would be assessed based on their symptoms and any evidence of TB on CXR if there is no evidence of active infection on the basis of symptoms and chest X-ray, the person should be treated for latent TB infection by the local multidisciplinary TB team to prevent progression to active disease

Question 38

What are the advised drug regimens to treat latent TB?

Answer 38

* 3 months of isoniazid with rifampicin * or * 6 months of isoniazid

Question 39

What side effects come from rifampicin and isoniazid and what drug is given with isoniazid and why?

Answer 39

Rifampicin causes orange pee and tears Izoniazid inhibits formation of active pyridoxine (vit B6) which can lead to peripheral neuropathy- therefore give with prophylactic pyridoxine

Question 40

Suspect active TB in any person who is at high risk of developing TB and has general (consitutional symptoms) symptoms Whare the symptoms of TB (pulmonary TB)?

Answer 40

Asian man + night sweats - buzzword for TB Suspect active TB in any person who is at high risk of developing TB and has general symptoms of weight loss, fever, night sweats, anorexia, or malaise.(NICE) Pulmonary symptoms include - cough lasting longer 3 weeks - initially dry then productive, pleurisy, uncommon to see haemoptysis and pleural effusion but happens

Question 41

* In someone with suspected TB, the first test to carry out is a CXR What is seen on CXR?

Answer 41

Can see nodular opacities in upper lobes and cavitations (thick walled abnormal ags filled spaces within the lung)

Question 42

* In someone with suspected TB, the first test to carry out is a CXR * Consider arranging three respiratory samples, particularly if chest X-ray appearances suggest TB infection. How are these sputum samples ideally collected?

Answer 42

Ideally the three samples should be spontaneously produced, deep cough sputum samples with preferably one in the morning

Question 43

What are the three tests carried out on the three sputum samples? Which test although the longest is the most sensitive and specific? What test should be offered to all patients with confirmed TB?

Answer 43

Carry out * Sputum smear test- microscopy for acid fast bacilli * Nucleic acid amplification testing (NAAT) - direct and rapid detection of M.tuberculosis * Sputum culture - takes longer but MOST SENSITIVE AND SPECIFIC - can assess drug sensitivity OFFER HIV TEST TO ALL WITH CONFIRMED TB

Question 44

What is the treatment of tuberculosis? State the drug side effects

Answer 44

2 months intensive * Rifampicin - orange tears and urine, rashes * Isoniazid (with pyridoxine) - peripheral neuropathy (tingling/paraesthesia of extrimities), hepatotoxic * Pyrazinamide - joint pain worsening gout, hepatotoxic * Ethambutol - optic neuritis, colour blindness 4months continuation * Rifampicin * Isoniazid (with pyridoxine)

Question 45

What drugs should you be careful with when using rifampicin?

Answer 45

Rifampicin is an inducer of the CytP450 enzyme and therefore reduces the efficacy of many drugs eg the combined oral contraceptive and of warfarin

Question 46

What is the spread of tuberculosis in the blood stream known as? What does this cause to the CXR of the lungs?

Answer 46

A potentially more serious, widespread form of TB is called “disseminated tuberculosis”, it is also known as miliary tuberculosis - TB spreads through the bloodstream and canspread throughout the body CXR shows small nodular opacities throughout the lung in MTB