Pneumonia - Community-Acquired Công cụ chẩn đoán

Imaging

Patients with severe community-acquired pneumonia should be managed in a hospital setting. Direct ICU admission is recommended for patients with hypotension or shock requiring vasopressors or respiratory failure needing mechanical ventilation, altered mental status, or pneumonia with multiorgan impairment.  

CRB65 or CURB65 Score for Mortality Risk Assessment  

CRB65 or CURB 65 scoring may be used as a prognostic baseline for patients with community-acquired pneumonia. CRB65 is used in primary care while CURB65 is used for hospitalized patients.  

The prognostic features for CRB65 or CURB65 are as follows wherein 1 point is given for each feature present:

• C stands for confusion or having an abbreviated mental test score <8 or new disorientation
• U stands for uremia or increased blood urea nitrogen (BUN) of >7 mmol/L or >20 mg/dL
• R stands for respiratory rate that is increased at ≥30 breaths/minute
• B stands for blood pressure that is decreased at 90/≤60 mmHg
• 65 stands for an age of ≥65 years old

• CRB65:
  • CRB65 0: Low-risk (<1% mortality risk)
  • CRB65 1-2: Intermediate-risk (1-10% mortality risk), other features include:
    • Extrapulmonary evidence of sepsis, suspected aspiration, or unstable comorbid conditions
    • Chest X-ray findings of multilobar involvement, pleural effusion abscess, or progression of the lesion to >50% of initial within 24 hours
    • Urea >7 mmol/L
  • CRB65 3-4: High-risk (>10% mortality risk), other features include:
    • Shock or signs of hypoperfusion (ie hypotension, altered mental state, urine output <30 mL/hr)
    • Acute hypercapnia (PaCO₂ >50 mmHg)
• CURB65:
  • CURB65 0-1: Low-risk (<3% mortality risk)
  • CURB65 2: Intermediate-risk (3-15% mortality risk)
  • CURB65 3-5: High-risk (>15% mortality risk)

• Demographic factors:
  • Men: Age (year)
  • Women: Age (year) - 10
• Nursing home residents: + 10
• Comorbid illnesses:
  • Neoplastic disease: + 30
  • Liver disease: + 20
  • Congestive heart failure: + 10
  • Cerebrovascular disease: + 10
  • Renal disease: + 10
• Physical examination findings:
  • Altered mental status: + 20
  • RR ≥30 breaths/minute: + 20
  • Systolic BP <90 mmHg: + 20
  • Temperature <35°C or ≥40°C: + 15
  • Pulse ≥125 beats/minute: + 10
• Laboratory and imaging findings:
  • Arterial pH <7.35: + 30
  • BUN ≥30 mg/dL (≥10.7 mmol/L): + 20
  • Sodium <130 mEq/L: + 20
  • Glucose ≥250 mg/dL (≥13.9 mmol/L): + 10
  • Hematocrit <30% PaO₂ <60 mmHg or O₂ saturation <90%: + 10
  • Pleural effusion: + 10 

Based on the score, patients are classified according to their risk class, and listed here are the management strategies for each:

• For Class I (Low-risk): No predictors are present: Outpatient therapy
• For Class II (Low-risk): ≤70 points; mortality estimated at 0.6%: Outpatient therapy except for patients with respiratory rate of ≥30 breaths/minute, PaO₂/FiO₂ ratio of ≤250 mmHg, systolic blood pressure of <90 mmHg, diastolic blood pressure of <60 mmHg, multilobar infiltrates and confusion
• For Class III (Low-risk): 71-90 points; mortality estimated at 0.9%: May be managed as an outpatient depending on clinical status, available resources, and other factors; and an option for at-home parenteral antibiotic therapy or brief hospitalization (<24 hours)
• For Class IV (Moderate-risk): 91-130 points; mortality estimated at 9.3%: Inpatient therapy
• For Class V (High risk): >130 points; mortality estimated at 27%: Inpatient therapy 

Laboratory Tests and Ancillaries

A chest X-ray is useful for determining the severity the of disease and the presence of complications. It typically shows lobar consolidation and may also show bilateral, more diffuse infiltrates. It may also suggest possible etiology, reveal associated conditions, and assist in differentiating pneumonia from other conditions that may present similarly.