CURB-65 Guided Treatment for Pneumonia in Older Adults
For older adults with pneumonia, use CURB-65 to stratify treatment: scores 0-1 warrant outpatient oral antibiotics, score 2 requires hospitalization or intensive home monitoring, and scores ≥3 mandate hospital admission with immediate ICU assessment. 1, 2
Understanding CURB-65 Scoring
CURB-65 assigns one point for each of five criteria: Confusion, Urea >19 mg/dL (>7 mmol/L), Respiratory rate ≥30 breaths/min, Blood pressure (systolic <90 mmHg or diastolic ≤60 mmHg), and age ≥65 years, yielding a 0-5 point scale. 1, 2
The mortality risk escalates dramatically with each point:
- Score 0: 0.7-1.1% mortality 2, 3
- Score 1: 2.1% mortality 1, 3
- Score 2: 9.2% mortality 1, 2
- Score 3: 14.5-21% mortality 1, 3
- Score 4: 40-41.9% mortality 1, 3
- Score 5: 57-60% mortality 1, 3
Treatment Algorithm by CURB-65 Score
Low Risk: CURB-65 Score 0-1
Outpatient treatment is safe and appropriate. 4
For healthy adults without comorbidities: Use amoxicillin 1 g three times daily OR doxycycline 100 mg twice daily. 1
For adults with comorbidities (diabetes, heart disease, COPD, immunosuppression): Use combination therapy with amoxicillin/clavulanate or cephalosporin PLUS a macrolide. 1
Expect clinical improvement within 3 days; patients should contact their physician if no improvement occurs. 1
Intermediate Risk: CURB-65 Score 2
This score carries 9.2% mortality and requires hospitalization or intensive in-home health services where available. 1, 2 The American Academy of Family Physicians emphasizes that clinical judgment is particularly critical in this intermediate risk group. 5
- Consider hospitalization for most patients given the substantial mortality risk. 2
- If intensive home health services are available and social circumstances permit, supervised outpatient treatment may be considered. 5
High Risk: CURB-65 Score ≥3
Hospital admission is mandatory with prompt evaluation for ICU care. 1, 2 Mortality ranges from 14.5% to 60% in this group. 1, 3
- Assess immediately for ICU admission using IDSA/ATS severe CAP criteria (see below). 2, 5
- Direct ICU admission is required for septic shock requiring vasopressors or acute respiratory failure requiring intubation. 5
Critical ICU Triage Considerations
CURB-65 alone performs poorly for ICU decisions (sensitivity only 78.4% for predicting critical care interventions); use IDSA/ATS severe CAP criteria instead. 5, 6
Major Criteria (Either One Mandates ICU):
- Septic shock requiring vasopressors 5
- Acute respiratory failure requiring intubation and mechanical ventilation 5
Minor Criteria (≥3 Warrant ICU or High-Level Monitoring):
- Respiratory rate ≥30/min 5
- PaO2/FiO2 ratio ≤250 5
- Multilobar infiltrates 5
- Confusion/disorientation 5
- Uremia 5
- Leukopenia 5
- Thrombocytopenia 5
- Hypothermia 5
- Hypotension requiring aggressive fluid resuscitation 5
Critical Pitfalls and Limitations
Age-Related Underestimation
CURB-65 may dangerously underestimate severity in young patients (<65 years) with severe respiratory failure who lack age points despite significant physiologic derangement. 1, 2 A previously healthy 45-year-old with severe hypoxemia may score only 1-2 points yet require ICU care. 5
Overestimation in Stable Elderly
Conversely, elderly patients with multiple stable comorbidities may have falsely elevated scores without true severity. 2, 5
Low Blood Pressure Variability
Research shows that low blood pressure may not consistently predict mortality in very low-mortality settings, though confusion shows the strongest association (odds ratio 22.148). 7
ICU Admission Performance
Among patients with CURB-65 scores 0-1,15.6% were admitted to ICU and 6.4% received critical care interventions in one large study, highlighting the score's limitations for disposition decisions. 6
Non-Clinical Factors Requiring Hospitalization
Consider hospitalization despite low CURB-65 scores for:
- Inability to maintain oral intake 2, 5
- Homelessness or lack of social support 2, 5
- Severe psychiatric illness 2, 5
- Injection drug abuse 2
- Failure of prior adequate outpatient antibiotic therapy 4
- Important comorbidities not captured by CURB-65 (HIV, active malignancy) 4
Simplified Alternative: CRB-65
When laboratory testing is unavailable, use CRB-65, which omits the urea measurement and scores 0-4 points. 4 This is particularly useful in outpatient settings and resource-limited environments. 5
Implementation Best Practices
Use CURB-65 as an adjunct to clinical judgment, not as the sole determinant for site-of-care decisions. 4, 2 The American Thoracic Society, British Thoracic Society, and IDSA all emphasize that prediction tools support but do not replace clinical judgment. 4
Implement CURB-65 as part of a systematic pneumonia care bundle including pulse oximetry and point-of-care lactate, as postponing oxygenation assessment adversely affects outcomes. 5
Reassess for treatment failure, resistant organisms, or complications if fever persists beyond 72 hours. 1