PNEUMONIA


Definition:

  • Pneumonia is defined as inflammation with exudative solidification of lung parenchyma, generally acute.
  • Infection that inflames air sacs in one or both lungs, which may filled with fluid.

Classification:-

  • Anatomically

  1) Lobar/Lobular

  2) Bronchopneumonia

  3) Interstitial

  • Etiologically

  1) Primary pneumonia

  2) Secondary pneumonia

  3) Suppurative pneumonia

  • According to mode of acquiring:

  1) Community-acquired

  2) Nosocomial

  3) Pneumonia in immunocompromised patients

1) Primary pneumonia

       Caused by specific pathogenic organism

       No pre-existing respiratory abnormality

       Common organisms are Streptococcus pneumoniae, Haemophilus influenzae,                 Staphylococcus aureus, Moraxella catarrhalis, Legionella pneumophila, Mycoplasma peumoniae

  2) Secondary pneumonia

       Absence of specific pathogenic organism

       Presence of pre-existing abnormality of respiration

       E.g. Aspiration pneumonia– aspiration of food, secretion etc.

  3) Suppurative pneumonia

       Destruction of lung tissue by inflammation, abscess formation

Pathology:

  • Four stages:

   1) stage of congestion

   2) stage of red hepatization

   3) stage of grey hepatization

   4) stage of resolution/complication

Clinical features:

  •  Onset of rigors followed by fever
  •   Pleuritic chest pain
  •   Productive cough with purulent sputum  
  •   Haemoptysis
  •   Tachypnoea in elderly
  •   Tachycardia
  •   Crepitations over involved area
  •   Myalgia, arthralgia, headache, mental confusion

Investigations:

  •   DLC–leucocytosis
  •   Blood culture
  •   Respiratory secretions- culture, microscopy
  •   Serological and antigen detecting tests
  •   Radiological studies- chest radiograph confirms diagnosis

Complications:

  •  Parapneumonic effusion
  •   Meningitis
  •   Arthritis
  •   Endocarditis
  •   Pericarditis
  •   Peritonitis
  •   Empyema
  •   ARDS
  •   Septicemia

Treatment:

  • General measures:

 – check airway, breathing, circulation

 – iv fluids

 – oxygen

 – mild analgesics

  • Antimicrobial therapy:

– uncomplicated pneumonia:

     Erythromycin 250 mg 6 hourly alone or in combination with cefuroxime, fluoroquinolones may be given

  • moderate sick pts:

     Ceftriaxone 2 g once a day IV and erythromycin 500 mg 6 hourly

  • severely sick pts:

     Ceftriaxone 2 g once a day IV and azithromycin 500 mg IV or levofloxacin 5000mg IV once a day.