Pneumonia Overview and Classification

Pneumonia Overview

• Pneumonia is an acute infection of the lung tissue.
• About 4-5 million people in the US develop pneumonia annually, resulting in approximately 55,000 deaths.
• It ranks as the 9th leading cause of death.
• It's the most common cause of death in medically underserved areas.
• Pneumonia is an infection of the lung parenchyma.

Classification of Pneumonia

• Etiology: Bronchopneumonia vs. lobar pneumonia (segmental, lobar, or multilobar).
• Morphology:
  • Lobar pneumonia: Radiological and pathological; homogenous consolidation of one or more lung lobes, often with pleural inflammation.
  • Bronchopneumonia: Patchy alveolar consolidation linked to bronchial and bronchiolar inflammation, usually affecting both lower lobes.
• Community-acquired vs. hospital-acquired (nosocomial) pneumonia: Different pathogens and risk factors.
• Patient's immune status: Impacts susceptibility and severity.

Pathological Phases of Lobar Pneumonia

• Congestion (1-2 days): Pulmonary capillaries dilate; fluid leaks into alveoli. Symptoms: Fever, shortness of breath (SOB), cough.
• Red hepatization (2-4 days): Alveoli fill with red blood cells, neutrophils, and fibrin. Gas exchange is impaired. Symptoms: Breathlessness, hypoxic, blood-tinged or rusty sputum.
• Grey hepatization (4-8 days): Neutrophils and fibrinous strands fill the alveoli, leading to grey appearance. Symptoms: Purulent sputum, breathlessness.
• Resolution (8-10+ days): Monocytes clear debris, restoring normal lung tissue architecture. Improvement in patient condition.

Etiology of Pneumonia

• Bacterial: Streptococcus pneumoniae (most frequent).
• Viral: Adenoviruses, influenza, among others.
• Fungal: Histoplasma, Blastomyces, Coccidioides.
• Parasitic: Ascaris.

Lobar Pneumonia (Details)

• Affects a large, continuous area of a lung lobe.
• One of two major pneumonia classifications (the other being bronchopneumonia).

Pneumonia Symptoms

• High fever.
• Tiredness/fatigue.
• Sweating or chills.
• Cough (sometimes with yellow, green, or bloody mucus).
• Rapid breathing or increased heart rate.
• Shortness of breath (dyspnea).
• Chest or abdominal pain.
• Loss of appetite.
• Bluish skin, lips, or nails (cyanosis).
• Confusion or altered mental state

Pneumonia: Common Risk Factors and Presentations

• Community-acquired pneumonia (CAP):
  • Age extremes (very young and very old).
  • Alcohol misuse.
  • Chronic steroid use.
  • Cardiac, liver, or pulmonary diseases.
  • HIV/AIDS, immunosuppression.
  • Recent influenza.
  • Smoking.
• Hospital-acquired pneumonia (HAP):
  • Aspiration.
  • Supine positioning.
  • Swallowing problems.
  • Intubation, tracheostomy.
  • Elevated gastric pH.
  • ICU admission.
  • Immunosuppression.
  • Poor glycemic control.
  • Mechanical ventilation.

Pneumonia Treatment

• Assess airway, breathing, and circulation.
• Monitor SpO2 (oxygen saturation).
• Assess severity – severe pneumonia mandates hospitalization.
• Supplemental oxygen (to maintain SpO2 >94%).
• Supportive treatment (fluids, nutrition, fever management).
• Investigations (X-rays, blood tests).
• IV antibiotics (as indicated).

Explore the key aspects of pneumonia, a severe lung infection that affects millions annually. Understand the different types, including bronchopneumonia and lobar pneumonia, along with their classifications based on etiology and morphology. This quiz also highlights the impacts of the patient's immune status and the prevalence of pneumonia in various communities.