Pneumonia Flashcards
(68 cards)
1
Q
Why is pneumonia important
A
- common disease with high rates of hospitalisation
- it kills
- expensive to treat
- treatable
Presents to all specialities
- GP
- A and E
- acute/general medicine
- respiratory medicine
- ITU
- surgeons
- Oncology
- HIV
- Radiology
- Paediatrics
- care the elderly
2
Q
describe the epidemiology of pneumonia
A
• Incidence 5-11 cases/1000 adults
– 5-12% of respiratory infections presenting to GP’s
• Highest incidence in very young and very old
– BTS Audit – Mean age 71 (16-105) – 25% ≥85
• 22-42% require hospital admission in UK
• 5-7% need intensive care = 5% of ITU admissions – 50% Mortality
• 18.3% 30 day mortality
– 20% in first 24 hours – Median 5 days
• HAP affects 0.5-1% of inpatients
3
Q
What is pneumonia
A
Symptoms and signs consistent with an acute lower respiratory tract infection associated with new radiographic shadowing for which there is no other explanation
4
Q
What are the symptoms of pneumonia
A
Localised
- Cough and at least one other from:
- pleural pain
- dyspnoea
- tachypnoea
Systemic
- sweating, fevers, shivers, aches and pains and/or
- fever greater than 38 degrees
5
Q
What are the signs of pneumonia
A
- new and focal chest signs
- new radiographic shadowing with no other explanation
6
Q
How can you classify pneumonia
A
- aetiology
- patient factors
- clinical features
7
Q
how do you classify pneumonia according to the aetiology
A
Organism
Source of infection
- community acquired
- health care associated - hospital acquired, ventilator associated, nursing home
8
Q
How do you classify pneumonia according to patient factors
A
- underlying disease
- immunocompromise states
9
Q
how do you classify pneumonia according to clinical features
A
- severity
- symptoms and signs
10
Q
What organisms causes the most pneumonia
A
Strep Pneumoniae - greater than 50% of all cases
11
Q
in approximately 50% of pneumonia cases there is…
A
no pathogen identified
12
Q
what other factors can be used to help predict the organism that is causing the pneumonia
A
- Source of infection
- patient factors
- clinical features
13
Q
How do you define hospital acquired pneumonia
A
- defined as someone who has developed pneumonia who has been in hospital for more than 48 hours or 10 days post discharge
14
Q
What pathogens can cause hospital acquired pneumonia
A
Increased risk of
- aspiration
- H.influenzae
- Gram negative
- Staph aureus
15
Q
What patient factors can help predict the most likely pathogen causing pneumonia
A
- Elderly are less likely to have M.pneumoniae and Legionella
- Diabetes - increase in bacteraemic pneumococcal pneumonia
- COPD - increase in H.influenzae and M. Catarrhalis
- Alcoholism - more likely to have all organisms - consider aspiration as more likely to aspirate and more likely to be infected with anaerobic bacteria
- Immunodeficiency - still the most common cause but more likely to be due to legionella, neutropenic sepsis and TB, PCP etc
16
Q
clinical features cannot …
A
predict the likely pathogen
17
Q
what pathogens do you need to cover in hospital acquired pneumonia
A
- Most commonly gram negative enterobacteria or staph Aureus
- pseudomonas
- Klebsiella
- bactericides
- clostridia
– Cover Gram Negatives
– No need to cover Legionella
18
Q
what are the lung defence mechanisms
A
designed to treat a decrease in particle size as you go down the respiratory tract
- filtration/deposition in upper airways
- cough reflex
- mucociliary clearance
- alveolar macrophages
- humeral and cellular immunity
- oxidative metabolism of neutrophils
19
Q
what can cause defects in the airway host defences
A
- filtration/deposition in upper airways = anatomical abnormalities
- cough reflex = aspiration e.g. post stroke
- mucociliary clearance = cystic fibrosis, bronchiectasis
- alveolar macrophages = alcoholism
- humeral and cellular immunity = HIV
- oxidative metabolism of neutrophils = chemotherapy
20
Q
What has to happen in order for pneumonia to infect the body
A
Immune defence
- defect in host defence
- virulent organism
- overwhelming inoculum such as aspiration
21
Q
What investigations are needed in pneumonia
- aid and confirm diagnosis
- stratify severity/risk
- target therapy
A
Aid/confirm diagnosis
- chest radiograph - within 4 hours
- FBC (WCC usually >15x109/l)/CRP (usually >100mg/l)
Stratify severity/Risk
- urea and electrolytes
- FBC/CRP/(LFT)
- Oxygen saturations
- ABG
Target therapy
- blood and sputum cultures – Pneumococcal urinary antigen
– Legionella urinary antigen +sputum culture
– Mycoplasma PCR (Sputum/Throat swab)
– Chlamydophilia PCR/Complement fixation
– Viral PCR(Nose/Throat swab)
22
Q
What is the aim of microbiology
A
– Identify Pathogenic Bacteria
• Microscopy
– Test Sensitivity to Antibiotics
• Culture and Sensitivities
23
Q
what cultures can be used to assess the microbiology of the pneumonia
A
- Blood and/or Sputum Cultures
- urinary antigens - only for pneumococcus and legionella
- PCR - nose or throat swab for viruses
24
Q
what is urinary antigen test supposed to be for
A
- Pneumococcoal
- legionella – Only tests for Serogroup 1 (90% of European cases)
25
Describe urinary antigen tests
– Highly Sensitive (>80%) and Specific (>95%) – Rapid Result
– Remain Positive on Treatment
– No information on Antibiotic Sensitivities
– If positive → Specific sputum culture
26
When does staph aureus usually cause pneumonia
- winter
- 39% influenza symptoms
- 39% influenza virus - 50% of those admitted to ITU
27
What radiographic changes might you see in pneumonia
- Consolidation
- air bronchograms - highly suggestive on pneumonia
- shadowing
- collapse
- pleural effusion
- lymphadenopathy
28
What are air bronchograms
- dark lines going through a white area of lung
| - air bronchi surrounded by the pus in the alveoli
29
How long does it take for pneumonia changes on a radiograph
- 73% at 6 weeks, slower in the elderly or multi lobar
30
When would you use CT scanning in pneumonia
- diagnostic doubt
| - underlying cause such as cancer
31
How can you guide your treatment of pneumonia
CURB65
32
what is CURB65 made out of
- C - new confusion (AMTS less than or equal to 8)
- U - urea greater than 7mmol/l
- R - respiratory rate greater than 30/min
- B - blood pressure hypotensive
- 65 age over 65
33
What is the downside of CURB65
- requires a blood test result as you need to know the urea
- has binary cut offs
- young people blood pressure doesn't decrease until they are severely ill
34
as CURB65 score increases....
mortality increases
35
How do you treat pneumonia according to the CURB65 score
```
– 0-1 – Treat at home
• >50% of cost related to admission
• ↓Mortality
• ↓RiskofVTE
• ↓ Risk of Hospital Acquired Infection
```
– 2 – Short admission, oral antibiotics
– 3+ – Admit + urgent senior review
– 4-5 – Admit + Critical Care (ITU/HDU) Review
36
What else should be used in the treatment of pneumonia
* Oxygen – Aim for target saturations
* i.v. Fluids, analgaesia & DVT prophylaxis
* Chest Physio/sitting out + Nutritional support
* Smoking cessation
37
What antibiotics are used in pneumonia
- Beta lactam in mild pneumonia with a macrolide added in moderate to severe pneumonia
38
What organisms are resistant to penicillin that can cause pneumonia
– Legionella & Mycoplasma
| - but these are usually susceptible to macrolide
39
What is there route of antibiotics that should be given
Oral – Unless:
• CURB65 ≥3
• Unable to swallow
40
How long should the antibiotics be given for pneumonia
* Mild 5/7
* Moderate-Severe 7-10/7
* Atypicals 14-21/7
41
What can cause a failure to improve
Worried 3-4 days if not improving or getting worse
- repeat CXR/CRP at 3-4 days
Think about
– Incorrect diagnosis or complicating condition – Unexpected/resistant pathogen
– Impaired local or systemic immunity
– Local or distant complications of CAP
42
What should you consider if the CXR does not improve at 6 weeks
- consider bronchoscopy
| - CT
43
Why do you not give everyone broad spectrum antibiotics
Individual
- adverse consequences of antibiotics - MRSA and clostridium difficile
Society
- antibiotic resistance
44
what are strategies for antibiotic stewardship
* Ensure diagnosis secure
* Discontinue if not appropriate
* Narrow spectrum if specific pathogen identified
* i.v. → oral switch
* Stop dates on drug charts
45
Who is give the influenza vaccine
- all greater than 65 years + 2-4
greater than 6 months in an at risk group:
- asthma
- COPD
- chronic respiratory, heart, kidney, liver or neurological disease
- diabetes
- immunosuppression
- pregnant women
- healthcare workers
46
What are the benefits of the influenza vaccine
51-67% protection
– ↓Bronchopneumonia
– ↓Hospital Admissions
– ↓Mortality
47
Who is given the pneumococcal vaccination
- all over 65s
Greater than 2 years in an at risk group:
- same as influenza
- asplenia/splenic dysfunction - give 4-6/52 prior to splenectomy if possible
- cochlear implants
- CSF leaks
Revaccinate every 5 years
- Asplenia/splenic dysfunction
- CKD
48
Who should you revaccinate with pneumococcoal vaccination
- Asplenia/splenic dysfunction
| - CKD
49
describe what the pneumococcal vaccination does
- poorly protective
| - reduces septicaemia
50
define atypical pneumonia
The term ‘atypical pneumonia’ has outgrown its historical usefulness and we do not recommend its continued use as it implies (incorrectly) a distinctive clinical pattern
51
what is atypical pathogens used to define
• “The term ‘atypical pathogens‘ is used to define infections caused by:
– Mycoplasma pneumoniae – Chlamidophila pneumoniae – Chlamidophila psittaci
– Coxiella burnetii
52
What do atypical pathogens all share
•Difficult to diagnose early in illness
• Resistant to β-lactams
• Replicate intracellularly
• Mixed reports regarding specific symptoms:
– Mycoplasma:
• ?Younger & less systemic features.
• Epidemics
– C.pneumoniae – ?Headaches, longer prodrome & older
– C.psittaci – Acquired from birds but only 20% have bird contact
– C.burnetii – Younger males, dry cough & high fever
53
What is legionella caused by
Inhalation of aerosol from infected water source e.g. air conditioning
54
How do you differentiate clinically legionella
– Men
– Healthy younger patients
– Smokers
– Neurological or GI symptoms – Less respiratory symptoms
55
Who do you need to inform in legionella outbreak
Inform HPU to perform source investigation
56
When do you do the follow up for pneumonia
- follow up is at 6 weeks
57
How do you treat low severity pneumonia CURB65=0-1
```
Home
- amoxicillin 500mg tis orally
or
- Doxycycline 200mg loading dose then 100mg orally
or
- clarithromycin 500mg bd orally
```
58
How do you treat moderate severity pneumonia = CURB65=2
Hospital
- amoxicillin 500mg-1g tis orally plus clarithromycin 500mg bd orally
- if oral administration not possible amoxicillin 500mg tds IV or benzylpenicillin 1-2g QDS IV plus clarithromycin 500mg bd IV
or
- doxycycline 200mg daoding dose then 100mg orally
or
levofloxacin 500mg od orally or moxiflocaxin 400mg od orally
59
How do you treat high severity pneumonia CURB65=3-5
Hospital (consider critical care)
- antibiotics given as soon as possible
- Co-amoxiclav 1.2g tis IV plus clarithromycin 500mg bd IV
- if legionella strongly suspected consider adding levofloxacin
or
- benzylpencillin 1.2g qds IV plus either levofloxacin 500mg bd IV or ciprofloxacin 400mg bd IV
or
- cefuroxime 1.5g tds IV or cefotaxime 1g tds IV or ceftriaxone 2g od IV, plus clarithromycin 500mg bd IV
60
What are the clinical signs in consolidation
- expansion is decreased on affected side
- percussion is dull
- tactile vocal remits is increased over the affected area
- breath sounds are bronchial over the affected area
- vocal resonance is increased over the affected area
61
What are the clinical signs of lung collapse
- mediastinum is shifters toward the abnormal side
- expansion is decreased on the affected side
- percussion is dull over the affected area
- breath sounds are reduced
62
What are the clinical signs of pleural effusion
- the mediastinum is shifted away from the abnormal side
- expansion is decreased on the affected side
- percussion is dull
- tactile vocal remits is decreased over the effect side
- breath sounds are reduced over the affected area
- vocal resonance is decreased over the affected area
63
What is the difference between low pitched and high pitched sounds in pleural effusion
- Low pitched sounds have poorer transmission through a pleural effusion than a normal lung
- high pitched sounds appear to have slightly higher auscultatory transmission through a pleural effusion than a normal lung
64
describe the clinical signs for a pneumothorax
- expansion is decreased on affected side
- percussion is resonant over the affected area
- tactile vocal fremitus is decreased over affected area
- breath sounds are reduced over the affected area
- vocal resonance is decreased over the affected area
65
What antibiotics are used against pneumococcal pneumonia
- Amoxicillin
- benzylpenicillin
- cephalosporin
66
What antibiotics is used against staphylococcal pneumonia
- flucloxacillin and rifampicin
67
What antibiotics is used against klebsillea pneumonia
- cefotaxime
| - imipenem
68
What does the healing process of pneumonia look like
- 1 week – fever should have resolved
- 4 weeks – chest pain and sputum production should have reduced
- 6 weeks – cough and breathlessness should have reduced
- 3 months – most symptoms should have resolved but fatigue may still be present
- 6 months – people will feel back to normal
