Community-acquired pneumonia
Following a diagnosis of community-acquired pneumonia,
determine whether patients are at low, intermediate or high risk of death using the CRB65 score (mortality risk assessment).
CURB-65 Score (max=5)
Confusion No= 0 Yes= +1 (AMTS ≤8)
Urea>7 mmol/L No= 0 Yes= +1
Respiratory rate ≥ 30 No= 0 Yes= +1
SBP<90 or DBP≤60 No= 0 Yes= +1
Age ≥ 65 No= 0 Yes= +1
low severity CURB65 score 0 or 1 CRB65 score 0 Consider home-based
moderate severity CURB65 score 2 CRB65 score 1 or 2 Hospital asssessment
high severity CURB65 score 3 to 5 CRB65 score 3 or 4 Intensive care
CURB65 score risk of death as follows:
0 or 1: low risk (less than 3% mortality risk)
2: intermediate risk (3‑15% mortality risk)
3 to 5: high risk (more than 15% mortality risk)
Patient clinically unstable:
Temp>37.5 in the past 48 hours
Systolic BP <90 mm Hg
Heart rate >100/min
Respiratory rate >24/min
O2 sat<90% or PaO2 <60 mmHg in room air
Abnormal mental status
ADULTS
Assess severity
Clinical judgement AND guided by mortality risk score (CRB65 or CURB65)
Treatment
Offer an antibiotic(s) within 4 hours of diagnosis
Consider severity assessment when selecting antibiotic
Refer to secondary care if symptoms worsen rapidly (e.g. systemic sepsis) or do not improve <3d
Stop antibiotic treatment after 5 days
unless microbiological results suggest a longer course is needed or the person is not clinically stable.Mycoplasma pneumoniae infection occurs in outbreaks approximately every 4 years
Do not routinely offer microbiological tests for patients with low-severity CAP.
For patients with moderate‑ or high‑severity CAP test:
blood culture
sputum cultures
consider urinary antigen testing (pneumococcal and legionella)
low severity CURB65= 0 or 1
<3% mortality risk
Amoxicillin
+ atypical or penicillin allergy
Doxycycline
Clarithromycin
Erythromycin (in pregnancy)
moderate severity CURB65= 2
3-15% & mortality risk
Amoxicillin + Clarithromycin
Amoxicillin + Erythromycin (pregnancy)
Doxycycline
Clarithromycin
high severity CURB65= 3 to 5
>15% & mortality risk
Co-amoxiclav + Clarithromycin
Co-amoxiclav + Erythromycin (pregnancy)
+ penicillin allergy
*Levofloxacin
*Levofloxacin:
Very rare irreversible side effects affecting musculoskeletal and nervous systems.
Stop treatment if serious adverse reaction (such as tendonitis)
Caution in using antibiotic if age>60y
Avoid co-administration with corticosteroid
Oral or intravenous antibiotics?
Give oral antibiotics first line if possible
Review intravenous antibiotics by 48 hours and consider switching to oral antibiotics if possible
Failure to respond to antibiotics may indicate resistance or non-bacterial cause (e.g. flu)
Send a respiratory sample for microbiological testing?
If symptoms have not improved after antibiotics, send a sample (for example, a sputum sample) for microbiological testing.
How long symptoms are likely to last?
1 week: fever should have resolved
4 weeks: chest pain and sputum production reduce
6 weeks: cough and breathlessness reduce
3 months: most symptoms resoled, fatigue remains
6 months: normalised
Presentation with lower respiratory tract infection in the primary care
Consider a point of care C‑reactive protein test if there is diagnostic uncertainty.
Do not routinely offer antibiotic therapy if the CRP<20 mg/litre
Consider a delayed antibiotic prescription if CRP is 20-100 mg/litre
Offer antibiotic therapy if the CRP>100 mg/litre.
CHILDREN
In children and young people, severity is assessed by clinical judgement.
Consider sending sample (for example, a sputum sample) for microbiological testing
Non-severe symptoms
Amoxicillin
+ Atypical or penicillin allergy
Doxycycline
Clarithromycin
Severe symptoms
Co-amoxiclav
Co-amoxiclav + Clarithromycin (if atypical pathogen)