CAP-Community Acquired Pneumonia-Definition, Etiology and Its Management Protocols!

 COMMUNITY-ACQUIRED PNEUMONIA

Definition:

"It indicates pneumonia occurring in a person in a community (outside hospital)".

Predisposing factors:

1. Cigarette smoking
2. Upper GIT infection
3. Alcohol consumption
4. Corticosteroid therapy
5. Old age (pneumonia also called as Oldman's friend)
6. Recent influenzae
7. Indoor air pollution

Mode of Spread:

• Droplet infection

Infecting agents:

• S.pneumoniae
• S.aureus
• H.influenza
• Viruses- Influenza, Measles, Herpes simplex. Parainfluenza

Clinical Features:

• Pulmonary symptoms such as: Breathlessness, cough (non-productive or productive with sputum), hemolysis, pleuritic chest pain, shortness of breath.
• Systemic symptoms such as: fever with chills, rigors, tachycardia, vomiting, Decreased appetite, headache, fatigue.
• In elderly: new onset/ progressive confusion
• In severely ill: Septic shock, organ failure, tachypnea, percussion note dull to flat, bronchial breathing with crackles.

Investigations:

1. Chest Pain: to confirm the diagnosis and exclude complication.
2. Pulse Oximetry: to monitor response to oxygen therapy, if SaO2 < 93% features of sever pneumonia, identify ventilatory failure or acidosis.
3. Cell count: ESR, Neutrophil leukocytosis
4. Microbiological studies: for severe CAP and those that do not respond to initial therapy (Gram stain, sputum culture, blood culture)
5. Renal Function test: Urea and Electrolytes
6. Liver Function test: Elevated C-Reactive protein
7. Complete Blood Count (CBC)
8. Chest X-Ray

Management / Therapy:

The goal for management involves:

• Oxygen therapy
• Fluid balance
• Antibiotic therapy
• In severe illness--Nutrition support

1. Oxygen Therapy:

• Oxygen should be administered to all the patients with tachypnea, hypoxemia, hypotension with the aim of maintaining SaO2 at >92%.
• Indicated for: Referral to Intensive Therapy Unit (ITU) including.

1. Persistent hypoxia SaO2 <90% despite high concentration of O2.
2. Severe acidosis
3. Circulatory shock
4. Reduced conscious level.

2. IV Fluids:

• should be considered in patients with severe illness, older patients, those who are vomiting. Oral fluid intake is encouraged.

3. Antibiotics:

• Administration of antibiotics depends on whether Complicated CAP or Uncomplicated CAP

For Complicated CAP: 

Clarithromycin 500mg twice daily

                                   or 

Erythromycin 500mg 4 times daily IV    plus

Co-Amoxiclav 1.2g three times daily IV

                                  or

Ceftriaxone 1-2g daily IV

                                  or

Ceftriaxome 1.5g three times daily IV

                                 or

Amoxicillin 1g four times daily IV plus

Floxacillin 2g four times daily IV

For Uncomplicated CAP:

Amoxicillin 500mg three times daily orally

                            or

• If patient is allergic to penicillin

Clarithromycin 500mg two times daily orally

                           or

Erythromycin 500mg four times daily orally

• If Staphylococcus suspected/ cultured:

Floxacillin 1-2g four times daily IV plus

Clarithromycin 500mg two times daily IV

• If Mycoplasma suspected:

Clarithromycin 500mg two times daily oral/IV

                              or

Erythromycin 500mg four times daily orally plus

Rifampicin 600mg two times daily IV