Patho..Pneumonia

Causative Agent S. Pneumoniae

Pathophysiology of Pneumonia

Failure of First Line of Defense ( Cough and Sneezing Reflex)

Microbes multiply in trachea

Ciliary Action Overwhelmed

Failure of Second Line Defense ( Ciliary Action )

Microbes reach alveoli

WBC migrate & accumulate in the alveoli

Inflammatory reaction occurs in alveoli

Red Hepatization

Neutrophils, RBC’s & fibrin accumulate in alveolar exudate

WBC & macrophage release pyrogen

Consolidation

Forms a solid mass in the lobe

Pyrogen circulates in the blood

Consolidation exudate undergoes enzymatic digestion (Purulent fluid)

Stimulation of  hypothalamus to reset at high level

Release of chemical mediators such as histamine, cytokines and prostaglandins

Capillary Permeability

Accumulation of fluid in alveoli Gray Hepatization

B

C

Alveolar Edema

A

Vasodilation

Blood flow

RALES

B

C

Inflammatory exudate is absorbed/expectorated

Activation of heat production mechanisms

Allows Expectoration

PRODUCTIVE COUGH WITH RUSTY SPUTUM

CHILLS

FEVER

A

Pleural Effusion occurs

Flow of air in the alveolus is blocked

Inadequate ventilation of  the lungs

Infection of  the pleural membrane

Impaired gas exchanged

Alveolar  oxygen tension

O2 in the blood

Ventilationperfusion mismatch

O2 supply in

DYSPNEA

HR

Local irritation of  nerve endings during coughing and deep breathing

PLEURITIC CHEST PAIN

o2 supply in muscles

Anaerobic respiration

Production of lactic acid

MUSCLE PAIN

tissues

Stimulation of  carotid & aortic chemoreceptors

Stimulation of  the respiratory Center 

RR

o2 supply in brain

HEAD ACHE