Pneumonia & Chest Infections Flashcards
Define pneumonia
- symptoms and signs consistent with an acute LRTI
- associated with new radiographic shadowing
- no other explanation
Local symptoms
- cough AND 1 of - pleural pain - tachypnoea - dyspnoea
Systemic symptoms
- sweating
- fevers
- shivers
- aches
- pains
AND/OR - fever>38
Signs
New and focal chest signs
- new radiographic shadowing with no other explanation
Types
CAP
HAP
VAP (ventilator acquired)
What common organism causing it?
S. pneumoniae
Just under 50% of all
Other organisms causing it
H. influenzae Leigonella spp Staphylococcus M. catarrhalis M. pneumoniae Chlamydophilia spp Viruses
Most common causes for HAP
- H. influenzae
- Gram negative
- Staph aureus
- low legionella
RF
- elderly
- chronic illness
- alcoholism
- immunodeficiency
Common organisms causing pneumonia in elderly
M. pneumoniae
Legionella
Presentation less classical
Common chronic illnesses causing it
diabetes
COPD
Cause of pneumonia with steroid use
Legionella
Cause of pneumonia if on chemo
Fungal
Cause of pneumonia if have HIV/AIDs
TB
Lung defence mechanisms
Filtration/deposition in upper airways Cough reflex Mucociliary clearance Alveolar macrophages Humoral and cellular immunity Oxidative metabolism of neutrophils
How are lung defence mechanisms defected?
- anatomical abnormalities
- aspiration
- CF/bronchiectasis
- alcoholism
- HIV
- chemo
How are defence mechanisms overcome?
- defected in host defence
- virulent organism
- overwhelming inoculum = aspiration
Ix for diagnosis
- CXR
- FBC
FBC Results
WCC >15 x10^9/l
CRP >100mg/l
Ix for risk assessing
U&E
FBC/CRP/LFTs
Ox sats
ABG
Ix to assess targeted therapy need
- blood culture
- sputum culture
- pneumococcal urinary antigen
- legionella urinary antigen
- mycoplasma ACT
- chamydophilia PCR
- viral PCR
Ix in hospitalised
CXR FBC U&E CRP Ox sats
MC&S
- microbiology
- to identify pathogenic bacteria
- test sensitivity to antibiotics
- send quickly
Urinary Antigens
- highly sensitive and specific
- rapid result
- remain positive when treat
- no info. on AB sensitivity
- only for pneumococcal and legionella
- if positive = specific sputum culture
Influenza Ix
Nose/throat swab PCR
Radiological Ix
- consolidation
- shadowing
- air bronchograms!!!
- pleural effusion
- lymphadenopathy
- 6w mostly resolved
- if diagnostic doubt or to check if underlying cause = cancer
Procedure for predicted prognosis
- decision to admit
- microbiological Ix
- treatment
- refer to ICU
Factors for poor prognosis
Old age Pre-existing comorbidities High RR Confusion Low BP RF/hypoxaemia WCC>20 or <4 Bilateral progressive CXR changes Positive blood cultures Biochemical markers = CRP, lactate, troponin
CURB 65 measurements
C = confusion (AMTS ≤ ) U = urea >7 RR ≥ 30 BP <90 and/or <60 ≥ 65
CURB 65 criteria
0-1 treat at home
2 = short admission, oral AB
3 = admit and urgent senior review
4-5 = admit and critical care (ITU/HDU) review
CURB 65 0-1 Risks
- low risk of VTE, HAP
Mortality low
management of pneumonia
Oxygen = aim for 88-92%
IV fluids, analgesia, DVT prophylaxis
Chest physio/sitting out and nutritional support
Smoking cessation
AB Used
Beta lactam (+macrolide if moderate-severe)
e.g amoxicillin 500mg
Immediately after diagnosis by CXR
Oral unless CURB 65≥3 or unable
Which organisms are resistant?
Legionella and mycoplasma penicillin resistant but not macrolide
S. penumoniae most sensitive to pen and macrolides
How long is the AB course?
Mild = 5 days Mod-severe = 7-10 days Atypical = 14-21 days
Alternative treatment to amoxicillin
doxycycline 200mg loading then 100mg orally
OR
clarithromycin 500mg bd orally
Moderate severity AB treatment
- amoxicillin 500mg -1g tds orally
PLUS - clarithromycin 500mg bd orally
Moderative severity AB treatment if oral not possible
- amox 500mg tds IV
OR - benzypenicillin 1.2g qds IV plus clarithromycin 500mg bd IV
High severity AB treatment
co-amoxiclav 1.2g tds IV
PLUS
Clarithromycin 500mg bd IV
If legionella strongly suspected = consider adding levofloxacin
AB for gram negative bacilli
Cefuroxime 1.5g tds or cefotaxime 1-2g tds IV or ceftriaxone 1-2g bd IV
S. aureus with MRSA AB
vancromycin 1g bd IV OR linezolid 600mg bd IV OR teicoplanin 400mg bd IV OR Rifampicin 600mg OD or bd orally/IV
What to check on follow up?
- CXR
- CRP
- at 3-4 days
What if failure to improve on follow up?
- incorrect diagnosis
- atypical/mixed/resistant pathogens
- impaired immunity
- complications = effusion, empyema
- CXR lags behind clinical picture
- slower in elderly and if multilobar
- repeat at 6w if no improvement
- consider CT/bronchoscopy
- up to 50 days full return
Adverse consequences of AB
- C difficile
- MRSA
- society AB resistance
Who is influenza vaccine offered to?
- > 65
- 2-4 yrs
- asthma
- COPD
- chronic resp/heart/kidney/liver/neuro disease
- diabetes
- immunosuppressed
- pregnant
- healthcare workers
Who is pneumococcal vaccine offered to?
>65 >2 yrs and at risk of - splenic dysfunction - cochlear implants - CSF leaks - revacc every 5 yrs if asplenia or CKD otherwise once
Atypical pathogens e.g.
M. penumoniae = young, less systmic
Chlamidophilia penumoniae = old, headache
Chlamidophila Psittaci
Coxiella burnetiid = young male, fever, dry cough
Properties of atypical pathogens
- difficult to diagnose
- resistant to beta lactams
- replicate IC
Legionella who?
- men
- healthy young
- smokers
- neurological or GI
- less respiratory symptoms
HAP define
In patient >48 hours
OR
<10 days since discharge
