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

1. Offer an antibiotic(s) within 4 hours of diagnosis

2. Consider severity assessment when selecting antibiotic

3. Refer to secondary care if symptoms worsen rapidly (e.g. systemic sepsis) or do not improve <3d

4. Stop antibiotic treatment after 5 days
   unless microbiological results suggest a longer course is needed or the person is not clinically stable.

5. Mycoplasma pneumoniae infection occurs in outbreaks approximately every 4 years

6. Do not routinely offer microbiological tests for patients with low-severity CAP.

7. 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?

1. Give oral antibiotics first line if possible

2. Review intravenous antibiotics by 48 hours and consider switching to oral antibiotics if possible

3. 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

1. In children and young people, severity is assessed by clinical judgement.

2. 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)