Pneumonia

Classification

• community-acquired pneumonia (CAP), acquired outside of hospital
• nosocomial pneumonia, acquired in hospital, further subdivided into
  • hospital-acquired pneumonia (HAP), acquired >= 48 hours after admission
  • ventilator-associated pneumonia (VAP), acquired >= 48 hours after intubation

Therapeutic decisions are further guided by immunocompetence, with immunocompromised patients having different potential pathogens, including fungal infections, parasites and uncommon viral/bacterial species.

Diagnosis

• history with fever, cough, dyspnea and sputum production
• vital signs including blood pressure, breathing rate, SpO2, mental state (GCS)
  • calculate qSOFA score
• laboratory findings
  • leukocytosis, early sign
  • elevated CRP, can lag behind leukocytes
  • elevated PCT is highly specific for bacterial infections
  • urea is needed for CURB-65 score
• arterial blood gases for respiratory insufficiency
• auscultation
• imaging
  • chest X-ray can often identify consolidations/infiltrates/cavitations
  • CT can provide further clarification in inconclusive or negative radiographs
  • ultrasound can identify pleural effusions

Microbiological testing

• blood cultures
• sputum cultures/stain
• urinary testing for S. pneumoniae
• testing for Legionella spp. (PCR or urinary antigen test)
• viral testing (SARS-CoV-2, influenza and other seasonal viruses depending on season)
• severe pneumonia: bronchoscopic samples
• tuberculosis and fungi in cavitary pneumonia
• consider extended spectrum of pathogens (including fungi, uncommon viruses, Pneumocystis jirovecii, etc.) in immunocompromised patients

Further management

• CURB-65 score

  • C = confusion
  • U = urea > 7 mmol/L (= 19,6 mg/dL)
  • R = respiratory rate >= 30/min
  • B = blood pressure, diastolic <= 60 mmHg/systolic < 90 mmHg
  • 65 = age >= 65

• PSI-Score

• CURB-65 > 1 or PSI-Score >= III: hospitalize patient

• CURB-65 >= 3 or PSI-Score V consider intensive care

Therapy

• CAP
  • outpatient:
    • amoxicillin (addition of macrolide is sometimes recommended)
    • amoxicillin-clavulanate plus macrolide can be considered in smokers or patients with comorbidities
  • hospitalized patients:
    • beta-lactam antibiotic, addition of macrolide is sometimes recommended. Alternatively fluoroquinolones can be considered (monotherapy)
    • check history for recent antibiotics or prior infections with Pseudomonas, consider antipseudomonal beta-lactam (piperacillin-tazobactam, etc.)
    • in known/suspected MRSA infection consider vancomycin or linezolid
• HAP/VAP
  • therapeutic decisions should be guided by local distribution of pathogens, use local guidelines for antibiotic therapy
  • account for risk for multi drug resistant pathogens
    • recent IV antibiotics
    • long hospitalization
    • patient history
  • account for risk for MRSA
    • based on local distribution of pathogens
    • previous history of MRSA

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