What are the criteria for admitting an adult patient with pneumonia to the hospital?

Hospital Admission Criteria for Adult Pneumonia

Adults with pneumonia should be hospitalized if they have a CURB-65 score ≥2, which corresponds to a mortality risk of 9.2% or higher and indicates need for active intervention. 1, 2, 3

Primary Assessment: CURB-65 Scoring System

The IDSA/ATS guidelines strongly recommend using CURB-65 as the primary tool for admission decisions because it directly measures illness severity rather than just mortality risk. 1, 2

CURB-65 Components (1 point each): 2

• Confusion (new onset)
• Uremia (BUN ≥20 mg/dL)
• Respiratory rate ≥30 breaths/min
• Blood pressure (systolic <90 mmHg or diastolic ≤60 mmHg)
• Age ≥65 years

Risk Stratification and Disposition: 2, 3

• Score 0-1: Mortality 0.7-2.1% → Consider outpatient treatment
• Score 2: Mortality 9.2% → Hospitalize or provide intensive home health services
• Score 3: Mortality 14.5% → Hospitalize and assess for ICU
• Score 4-5: Mortality 40-57% → Hospitalize and assess for ICU

Absolute Indications for Hospitalization (Regardless of CURB-65)

Physiologic Instability: 3

• Oxygen saturation <90-92% on room air or PaO₂ <60 mmHg
• Respiratory rate >30 breaths/min
• Systolic blood pressure <90 mmHg or diastolic <60 mmHg
• Septic shock or need for vasopressors
• Acute respiratory failure requiring intubation

Clinical Complications: 3

• Pleural effusion or empyema
• Multilobar involvement
• Metastatic infection
• Suspected bacteremia

Functional/Social Barriers: 1, 3, 4

• Inability to reliably take or tolerate oral medications
• Intractable vomiting
• Lack of adequate caregiver support or social resources
• Homelessness or psychiatric illness preventing adherence

High-Risk Comorbidities: 3, 4

• Immunocompromised status (HIV, immunosuppression)
• Moderate to severe COPD
• Heart failure
• Chronic renal or liver disease
• Active malignancy
• Functional asplenia

ICU Admission Criteria

Immediate ICU Admission Required: 1, 3

• Septic shock requiring vasopressors
• Acute respiratory failure requiring intubation and mechanical ventilation

ICU or High-Level Monitoring Unit When ≥3 Minor Criteria Present: 1, 3

• Respiratory rate ≥30 breaths/min
• PaO₂/FiO₂ ratio <250
• Multilobar infiltrates
• Confusion
• Blood urea nitrogen ≥20 mg/dL
• Leukopenia from infection (WBC <4,000/μL)
• Thrombocytopenia
• Hypothermia (temperature <36°C)
• Hypotension requiring aggressive fluid resuscitation

Critical Point: CURB-65 alone performs poorly for predicting ICU needs (sensitivity only 78.4% for critical care interventions). 5 Use the IDSA/ATS severe CAP criteria above for ICU triage decisions rather than relying solely on CURB-65 score. 2

Common Clinical Pitfalls to Avoid

Underestimation of Severity: 2, 3, 5

• Young patients (<65 years) with severe respiratory failure may have low CURB-65 scores despite critical illness—15.6% of patients with CURB-65 0-1 required ICU admission and 6.4% received critical care interventions 5
• Previously healthy patients can develop severe CAP requiring ICU care 1
• Approximately 27% of patients with CURB-65 score of 2 were admitted to ICU and 15.4% received critical care interventions 5

Delayed Recognition: 1

• Up to 45% of patients ultimately requiring ICU care are initially admitted to general medical floors 1
• Delayed transfer to ICU for respiratory failure or septic shock is associated with increased mortality 1

Over-reliance on Scoring Systems: 1, 3

• Objective scores must be supplemented with clinical judgment regarding ability to take oral medications and availability of support resources 1
• Approximately 7.5% of patients initially treated as outpatients require subsequent hospitalization within 10 days and have higher mortality risk 3

Mandatory Follow-Up for Outpatient Management

If treating as outpatient (CURB-65 0-1 only): 3, 4

• Clinical reassessment must be planned within 24-48 hours
• Patient must be able to reliably take oral medications
• Adequate caregiver support must be available
• Contact physician if no improvement within 3 days 2

When in doubt, hospitalize—the consequences of missed severe pneumonia far outweigh the costs of potentially unnecessary admission. 3