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• Fatigue/Malaise: A general feeling of being unwell, tired, and lacking energy. Sarah appears ill.
• Headache: Can be present.
• Myalgia: Muscle aches.
• Anorexia: Loss of appetite.
• Gastrointestinal symptoms: Nausea, vomiting, or diarrhea can occur, especially with certain pathogens.

2. Describe the typical findings on physical examination and chest X-ray in patients with pneumonia.

Typical Physical Examination Findings in Pneumonia:

• Vital Signs:
  • Fever: Elevated temperature (101.2∘F in Sarah’s case).
  • Tachypnea: Increased respiratory rate (20 breaths/min in Sarah’s case, which is slightly elevated).
  • Tachycardia: Increased heart rate (90 bpm in Sarah’s case, which is slightly elevated).
  • Hypoxemia: (Not directly measured in vital signs, but often present) Decreased oxygen saturation.
• General Appearance: Patients often appear ill, fatigued, or distressed, as noted for Sarah.
• Respiratory System:
  • Inspection: Increased work of breathing, use of accessory muscles, nasal flaring, cyanosis (in severe cases).
  • Palpation: Increased tactile fremitus over the affected area (vibrations felt on the chest wall when the patient speaks).
  • Percussion: Dullness to percussion over the consolidated areas of the lung (where the lung is filled with fluid or inflammatory cells).
  • Auscultation: This is key.
    • Decreased or Bronchial Breath Sounds: Over the consolidated areas. Sarah had decreased breath sounds.
    • Crackles (Rales): Fine or coarse crackles (popping sounds) heard, especially during inspiration, due to fluid in the alveoli. Sarah had crackles bilaterally.
    • Egophony: An “E” sound heard as “A” over consolidated lung.
    • Whispered Pectoriloquy: Whispered words heard clearly through the stethoscope over consolidated lung.
    • Pleural Friction Rub: If pleurisy is present (inflammation of the pleura).

Typical Chest X-ray Findings in Pneumonia:

• Infiltrates: This is the hallmark radiological finding. Infiltrates appear as areas of increased opacity (whiteness) on the X-ray. Sarah’s chest X-ray showed infiltrates in bilateral lower lung fields. These can be:
  • Lobar Consolidation: Opacification of an entire lobe or segment of the lung, often associated with bacterial pneumonia.
  • Bronchopneumonia (Patchy Infiltrates): Multiple patchy areas of consolidation scattered throughout the lungs, often involving the airways. This can be seen in both bacterial and viral pneumonia.
  • Interstitial Infiltrates: A reticular or nodular pattern, often more diffuse, suggestive of viral or atypical pneumonia.
• Air Bronchograms: Lucent (dark) air-filled bronchi visible within an opaque (white) consolidated lung. This indicates that the alveoli around the bronchi are filled, but the bronchi themselves are patent.
• Pleural Effusion: Fluid accumulation in the pleural space, appearing as blunting of the costophrenic angles or a fluid level.
• Cavitation: Formation of a cavity within the lung, which can occur with certain pathogens (e.g., Staphylococcus aureus or anaerobes).

3. What are the most common pathogens causing community-acquired pneumonia, and how would you choose empirical antibiotic therapy in this patient?

Most Common Pathogens Causing Community-Acquired Pneumonia (CAP):

The most common causes of CAP vary slightly based on patient age and comorbidities, but generally include:

1. Streptococcus pneumoniae (Pneumococcus): This is the single most common bacterial cause of CAP.
2. Mycoplasma pneumoniae: A common cause of “atypical pneumonia,” often seen in younger adults and can cause outbreaks.
3. Chlamydophila pneumoniae: Another common cause of “atypical pneumonia.”
4. Haemophilus influenzae: Especially common in patients with underlying lung disease (e.g., COPD).