Key Points
- Use the highest‑yield diagnostic test early; do not let testing delay time‑critical therapy.
- Set objective targets (hemodynamic, neurologic, respiratory) and reassess frequently.
- Plan definitive source control or immunomodulation when indicated; document follow‑up and patient education.
Algorithm
- Confirm radiographic pneumonia and assess severity with ATS/IDSA criteria.
- Start empiric antibiotics tailored to MRSA/PsA risk; obtain cultures and viral PCR before antibiotics if feasible.
- Provide oxygen/ventilatory support as needed; consider corticosteroids per guideline nuances.
- Reassess at 48–72 h; de‑escalate based on culture/PCR; transition to PO when stable; plan early mobilization and vaccination.
Clinical Synopsis & Reasoning
Use 2019 ATS/IDSA severe criteria (major/minor) and consider MRSA/Pseudomonas risk factors. Start guideline‑concordant empiric antibiotics, add anti‑MRSA only with risk factors, and support with oxygenation and early mobilization; de‑escalate by cultures and viral testing.
Treatment Strategy & Disposition
Stabilize ABCs. Initiate guideline‑concordant first‑line therapy with precise dosing and continuous monitoring. Escalate to advanced or procedural interventions based on explicit failure criteria. Define ICU, step‑down, and ward disposition triggers; involve specialty teams early.
Epidemiology / Risk Factors
- Risk varies by comorbidity and precipitants; see citations for condition‑specific data.
Investigations
| Test | Role / Rationale | Typical Findings | Notes |
|---|---|---|---|
| CXR or lung ultrasound | Diagnosis | Infiltrate consistent with pneumonia | LUS improves sensitivity |
| Severity assessment (ATS/IDSA) | Disposition | Major/minor criteria | ICU vs ward |
| Microbiology (blood/sputum), viral PCR | Pathogen ID | MRSA/PsA risk evaluation | De‑escalate by results |
Pharmacology
| Medication/Intervention | Mechanism | Onset | Role in Therapy | Limitations |
|---|---|---|---|---|
| Ceftriaxone + Azithromycin (or Doxycycline) | β‑lactam + macrolide | Hours | Severe CAP without MRSA/PsA risk | QT prolongation (macrolide) |
| Levofloxacin monotherapy (alternative) | Respiratory fluoroquinolone | Hours | β‑lactam allergy | Tendinopathy/CNS effects |
| Vancomycin or Linezolid (if MRSA risk) | Anti‑MRSA | Hours | Add only with risk factors (prior MRSA, recent influenza, cavitation) | Monitor levels/platelets (linezolid) |
Prognosis / Complications
- Outcome depends on timeliness of diagnosis and definitive therapy; monitor for complications.
Patient Education / Counseling
- Provide red‑flag education, adherence guidance, and explicit return precautions; arrange timely specialty follow‑up.
References
- 2019 ATS/IDSA Community‑Acquired Pneumonia Guideline — Link