CURB-65 Management Approach for Pneumonia
Use CURB-65 to stratify pneumonia patients into clear disposition categories: scores 0-1 can be treated at home, score 2 requires clinical judgment for short hospital stay or supervised outpatient management, and scores 3-5 mandate hospital admission with ICU assessment for scores 4-5.
CURB-65 Scoring System
Calculate one point for each of the following five criteria 1:
- Confusion (mental test score <8 or new disorientation in person, place, or time)
- Urea >7 mmol/L (blood urea nitrogen >19 mg/dL)
- Respiratory rate ≥30 breaths/minute
- Blood pressure (systolic <90 mmHg or diastolic ≤60 mmHg)
- 65 years of age or older
Risk-Stratified Management Algorithm
CURB-65 Score 0-1: Low Risk (Mortality 0.7-2.1%)
- Consider home treatment for these patients as they are at low risk of death 1, 2
- Outpatient oral antibiotics are appropriate 1
- No routine hospitalization required unless social factors preclude safe home care 1
Common pitfall: Even with low scores, 6.4% of patients with CURB-65 0-1 may still require critical care interventions, so ensure adequate outpatient follow-up 3
CURB-65 Score 2: Intermediate Risk (Mortality 9.2%)
- Consider short inpatient stay or hospital-supervised outpatient management 1, 2
- This decision requires clinical judgment and assessment of additional factors 1, 2
- Evaluate for comorbidities not captured by CURB-65 (HIV, immunosuppression, inability to take oral medications) 1
Critical consideration: 15.4% of patients with score 2 receive critical care interventions, so maintain low threshold for admission if clinical concern exists 3
CURB-65 Score 3-5: High Risk (Mortality 14.5-57%)
- Hospitalize immediately and manage as severe pneumonia 1, 2
- Scores 4-5 have 40-57% mortality and require ICU assessment 1, 2
- Score 3 has 14.5% mortality and warrants hospital admission with ICU evaluation 2
Special Circumstances Requiring Severe Pneumonia Management
Bilateral chest radiograph infiltrates consistent with primary viral pneumonia mandate severe pneumonia management regardless of CURB-65 score 1
Essential Hospital Investigations
For all hospitalized patients, obtain 1:
- Full blood count, urea and electrolytes, liver function tests
- Chest radiograph
- Pulse oximetry (if <92% on room air, obtain arterial blood gases)
- C-reactive protein if influenza-related pneumonia suspected
- ECG for patients with cardiac/respiratory complications or comorbidities
ICU Transfer Criteria
Consider HDU/ICU transfer for 1:
- CURB-65 scores 4-5
- Primary viral pneumonia (bilateral infiltrates)
- Persistent hypoxia (PaO₂ <8 kPa) despite maximal oxygen
- Progressive hypercapnia
- Severe acidosis (pH <7.26)
- Septic shock
Oxygen and Supportive Care
- Maintain oxygen saturation >92% or PaO₂ >8 kPa 1
- Assess need for intravenous fluids 1
- Treat worsening comorbid conditions according to disease-specific guidelines 1
Simplified Alternative: CRB-65
When blood urea nitrogen testing is unavailable, use CRB-65 (omits urea measurement, scored 0-4) 1, 2:
- Particularly useful in outpatient settings and resource-limited environments 2, 4
- Provides 90% availability compared to 65% for CURB-65 4
- Validated with comparable mortality prediction to CURB-65 4, 5
Important caveat: CRB-65 may misclassify 26% of deaths as low-risk in hospitalized patients, so use full CURB-65 when laboratory values are available 4
Key Clinical Limitations
- CURB-65 may underestimate severity in young patients with severe respiratory failure and elderly patients with multiple comorbidities 2
- The score performs less effectively for ICU admission decisions compared to IDSA/ATS severe CAP criteria 2
- Use CURB-65 as an adjunct to clinical judgment, not as the sole determinant for disposition decisions 1, 2, 6
- Consider factors not captured by the score: HIV status, failure of outpatient therapy, social barriers to medication adherence 1, 2