Snapshot
- A 77-year-old man is brought in by EMS after waking up in the middle of the night covered in sweat, with a high fever, and a coughing up yellow sputum. A chest xray is shown.
Introduction
- Definition
- infection of lung parenchyma that usually occurs in defined lobar patterns, though may also present more diffusely
- Clinically defined as fever, cough and new infiltrate on CXR
- Pathophysiology
- Risk factors
- damage to respiratory cilia
- mucus plugs
Classification
- Classic patterns include
- lobar
- may involve entire lung or be confined to 1 lobe
- brochopnuemonia
- acute inflammatory infiltrates from bronchioles into adjacent alveoli
- patchy distribution
- involves ≥ 1 lobes
- interstitial
- diffuse patchy inflammation localized to interstitial areas of alveolar walls
- distribution involving ≥ 1 lobes
- lobar
- generally less severe than lobar or bronchopneumonia
Presentation
- Symptoms
- classically presents with sudden-onset of
- fever
- dyspnea
- night sweats
- pleuritic chest pain
- atypical presentations are gradual in onset and flu-like
- dry cough
- headaches
- myalgias
- sore throat
- classically presents with sudden-onset of
- Physical exam
- auscultation of the lungs reveals
- decreased or bronchial breath sounds
- crackles/rales
- wheezing
- E-to-A egophany
- with consolidation
- percussion reveals
- dullness over affected lobe(s)
- tactile fremitus
- increased with consolidation
- auscultation of the lungs reveals
- decreased with pleural effusion
Evaluation
- CXR
- may show lung opacification/consolidation in affected lobe(s)
- establishes diagnosis in combination with Gram stain or culture
- CBC
- elevated WBC count
- Sputum Gram stain and cultures
- identify pathogen
- directs antimicrobial therapy
Treatment
- Pharmacologic
- empiric antibiotics directed at most likely pathogens (depends on clinical scenario)
- organism-specific antibiotics if organism identified