Week 3/4 - G - Chronic pulmonary infection - Lung Abscess, empyema, bronchiectasis/Chronic bronchial sepsis

Question 1

* What do patients with primary antibody deficiencies usually present with? What are the major hallmarks of an immune deficinecy?

Answer 1

Patients with primary antibody deficiencies usually present with sinusitis, otitis media and lung infections - rare but important not to miss * Serious infections - unresponsive to oral antibiotics * Persistent infections - early structural damage or chronic infections * Unusual infections - unusual organisms or sites * Recurrent infections- Two major or one major and recurrent minor infections in one year

Question 2

What is the difference between the innate and adaptive immune system?

Answer 2

* The first line of defense against non-self pathogens is the innate, or non-specific, immune response.The main purpose of the innate immune response is to immediately prevent the spread and movement of foreign pathogens throughout the body. * The adapative (acquired / specific) immunity is the second line of defence and consists of B and T cells. Acquired immunity creates immunological memory after an initial response to a specific pathogen, and leads to an enhanced response to subsequent encounters with that pathogen.

Question 3

The innate immune response consists of physical, chemical and cellular defenses against pathogens. Give examples of these defenses WHat does adaptive immune response consist of?

Answer 3

The innate immune response consists of * physical (eg skin, mucocilairy escalator, tears, saliva) * chemical (eg cytokines( * and cellular defenses eg natural killer cells, phagocytes, esooinophils, basophils) The adaptive immune response consists of T and B cells - Acquired immunity creates immunological memory after an initial response to a specific pathogen, and leads to an enhanced response to subsequent encounters with that pathogen.

Question 4

Which immune response is the basis of vaccination?

Answer 4

The adaptive immunity is the basis of vaccination - exposure to antigen results in creating of memory B and T cells - subsequent exposure results in enhanced response to pathogen

Question 5

Abnormal innate host defence is a risk factor for chronic pulmonary infection (problem with the barrier defences) * Damaged bronchial mucosa * Abnormal cells * Abnormal secretions What conditions are linked to each of the bullet points?

Answer 5

Damaged bronchial mucosa - eg due to smoking, recent pneumonia, maignancy Abnormal cilia - eg Kartagener’s syndrome, Young’s syndrome Abnormal secretions - Cystic fibrosis (other channelopathies)

Question 6

In these flashcards we are going to discuss forms of chronic pulmonary infection * Remember these can be caused by immunodeficiency, immunosuppresion, abnormal innate host defence and repeated insult What are some of the forms of chronic pulmonary infection?

Answer 6

* Intrapulmonary abscess * Empyema * Bronchiectasis * Chronic bronchial sepsis * Abnormal cilia - Kartageners, Young’s * Abnormal secretions - Cystic fibrosis,

Question 7

INTRAPULMONARY ABSCESS What is a lung abscess? aka intrapulmonary abscess

Answer 7

A lung abscess is a localised collection of puss which leads to the formation of a cavity usually with a thick wall (cavity is a gas filled space in the lung)

Question 8

What are the risk factors for of a lung abscess?

Answer 8

Common risk factors of a lung abscess include a preceding illness such as * pneumonia or * a predisposition to aspiration of gastric contents such as alcoholic stupour, or neurological disease * Bronchial obstruction eg by tumour or foreign body is a big risk factor

Question 9

What are the symptoms of a lung abscess?

Answer 9

Cough Swinging fever Purulent sputum production - foul smelling (aka putrid sputum) Pleuritic chest pain Weight loss

Question 10

What investigations are carried out in the diagnosis of a lung abscess? What do you see on CXR?

Answer 10

Blood culture and FBC - could show anaemia if haemoptysis and a neutrophilia Sputum microscopy, culture and cytology CXR - walled cavity often with an air-fluid level

Question 11

What are the common pathogens involved in a lung abscess? When is staphlococcus causing a lung abscess particularly common?

Answer 11

Bacteria Streptococcus pneumonia and staphylococcus (common particularly post-flu) E-coli and gram negatives Fungi - aspergillus

Question 12

How are lung abscess treated?

Answer 12

Treated according to antibiotics sensitivities May need to drain the abscess - postural drainage

Question 13

What conditions could cause septic emboli that may lead to a lung absces?

Answer 13

Septic emboli may enter the lung causing a lung abscess conditions that cause this include * Infected DVT * Septicaemia * Bacterial endocarditis - usually tricuspid valve (right heart endocarditis) * PWID - inject into groin, can cause infected emboli Due to the blood in these conditions passing through right side of heart and into the lungs, can cause a lung abscess

Question 14

EMPYEMA 57 % of all patients with pneumonia develop a pleural effusion What type of effusion is it? What is pus in the pleural fluid known as?

Answer 14

Pneumonia causing a pleural effusion is an exudative pleural effusion - caused by inflammation of the pleura by adjacent pneumonia leading to increased leakiness of the pleural capillaries Pus in the pleural space - empyema

Question 15

What is a pleural effusion caused by pneumonia or a lung abscess known as? There are three types of this effusion, what are they?

Answer 15

This is a parapneumonic effusion * Simple parapneumonic effusion * Complicated parapneumonic effusion * Empyema

Question 16

How is a pleural effusion diagnosed and what is best for diagnosing empyema? What is the D-sign (buzzword) in reference to for a pleural effusion)

Answer 16

Pleural effusion normally diagnosed on CXR - looks for the D-sign signifying loculation has occurred - fluid density that does not correspond to anatomical fissures Ultrasound is the preferred method for diagnosing pleural effusion - also shows septations

Question 17

There are different criteria for a simple parapneumonic effusion, complicated parapneumonic effusion and an empyema What are these? (think pH, glucose, LDH, pus)

Answer 17

Simple parapneumonic effusion * pH>7.2 * Glucose normal * LDH normal Complicated parapneumonic effusion or empyema * pH However in empyemea , there is pus present (no other tests required if pus has been identified)

Question 18

What is the treatment of a pleural effusion be it simple, complicated or empyema?

Answer 18

Simple parapneumonic effusion - drain via thoracentesis If complicated parapneumonic effusion - drain using a chest tube aka chest drain Also prescribe antibiotics

Question 19

What can an empyema cause that makes drainage difficult and how can this be managed?

Answer 19

Empyema can have adhesions/septations and form loculations (Fibrotic scar tissue may form in the pleural cavity (called loculation), preventing effective drainage of the fluid - these are small pockets of pus pleural fluid) Fibrinolytic (eg alteplase) or mucolytic (eg dornase alfa) might improve drainage by breaking down the thickened fluid

Question 20

What is the usual type of organism found in empyema? What are the broad spectrum antibiotics given in the intial treatment of empyema? When are anaerobic bacteria seen in empyem?

Answer 20

Normally gram positive bacteria are found in empyema Anaeorbic usually in severe pneumonia or poor dental hygiene cases causing empyema Usually initially IV amoxicllin (coverage against gram positive and negative bacteria) and metronidazole (coverage against anaerobic)

Question 21

BRONCHIECTASIS Define bronchiectasis?

Answer 21

Bronchiectasis is the result of chronic inflammation of the bronchi and bronchioles leading to leading to irreversible (permannet) dilatation and thinning of the airways

Question 22

What is the presentation of patients with bronchiectasis?

Answer 22

Patients will often present with recurrent chest infections with a persistent productive cough with mucupurulent sputum - may be bloody There is often no response or a short lived response to antibiotics for the infections

Question 23

What are signs of bronchiectasis on examination?

Answer 23

Patients presen with finger clubbing, coarse inspiratory crepitations, wheeze

Question 24

Why are recurrent infections a presenting symptom of bronchiectasis? ie how does the damage to the bronchi/bronchioles lead to an increased risk of infection

Answer 24

The inside walls of the bronchi are coated with sticky mucus, which protects against damage from particles moving down into the lungs. In bronchiectasis, one or more of the bronchi are abnormally widened. This means more mucus than usual gathers there, which makes the bronchi more vulnerable to infection. If an infection does develop, the bronchi may be damaged again, so even more mucus gathers in them and the risk of infection increases further.

Question 25

Bronchiectasis is often caused as a consequence of recurrent and/or severe infections secondary to an underlying disorder What are some of the causes of bronchiectasis? Does smoking cause it?

Answer 25

Congenital causes include Cystic fibrosis, Kartagener’s and Young’s syndrome Post invective causes are common eg after penumonia A causal role for tobacco smoke in bronchiectasis has not been demonstrated. Nonetheless, tobacco smoking can worsen pulmonary function and accelerate the progression of disease that is already present

Question 26

In patients who have been diagnosed with bronchiectasis, diagnostic testing for potential aetiology should be performed How is bronchiectasis diagnosed? What is seen on CXR? What is the diagnostic procedure?

Answer 26

Sputum culture is carried out to identify organism CXR carried out - can often see abnormal dilatation of the airways High resolution CT (HRCT) chest is the diagnostic procedure

Question 27

What is seen on HRCT when looking at bronchiectasis?

Answer 27

Can see dilatation of the bronchiii/bronchiole There is a specific sign called the Signet sign - where the bronchiole is wider than the neighbouring arteriole (should be the same size) White - artiole (head of signet ring) Red - bronchiole (actual ring part)

Question 28

What is the difference between bronchiectasis and chronic bronchial spesis?

Answer 28

Chronic bronchil sepsis has all the hallmarks of bronchiectasis (recurrent infections that are often unresponsive to antibiotics, cough with mucuopurluent sputum, shortness of breath) however there is no bronchiectasis on the HRCT Treatment of both conditions remains the same

Question 29

What are the main organisms causing bronchiectasis/chronic bronchial sepsis? Which organsim is often seen in patients with CF?

Answer 29

Main organisms are H.Influenza and strep pneumonia Pseudomonas is often seen in patients with CF having bronchiectasis

Question 30

What is the treatment of bronchiectasis? What guides the choice of antibiotics treatment?

Answer 30

Treatment inolves aiway clearance techniques and mucolytics eg dornase alfa Bronchodilators may be useful * Antibiotics choice are guided by previous sputum cultures * haemophilus influenza and strep - amoxicillin * Pseudomonas treated with oral ciprfoloxaicin (IV antibitoics in primary care)

Question 31

When patients are having 3 or more acute exacerbations of bronchectasis per year, what can be offered for treatment?

Answer 31

Low dose macrolide antibiotic have been shown to be effective in non-smokers

Question 32

IN ALL PATIENTS WITH CHRONIC PULMONARY INFECTIONS (ie intrapulmonary abscess, empyema, bronchiectasis, chronic bronchial sepsis) WHAT SHOULD BE SEARCHED FOR?

Answer 32

The diagnosis of chronic infection must lead to a search for underlying immune deficiency Ie an immunodeficinecy (congenital or acquired eg cancer) Immunosupression Abnormal innate host defence - eg abnormal cilia or secretions Repeated insult -ie aspiration or indwelling material