Disease & Conditions

PNEUMONIA-why it had been so popular till 2021 ?

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Pneumonia is the inflammation of the lung parenchyma caused by various microorganisms like bacteria, mycobacteria, viruses, fungi, etc.

Pneumonia and influenza are the most common cause of death from infectious diseases in the United States.

Pneumonia and influenza are the eighth leading cause of death in the united states.

CLASSIFICATION OF PNEUMONIA

There are mainly four types of pneumonia

a. community-acquired pneumonia(CAP)

b. hospital-acquired pneumonia(HAP)

c. pneumonia in the immunocompromised host

d. aspiration pneumonia

COMMUNITY ACQUIRED PNEUMONIA

Community-acquired pneumonia mainly occurs in community settings or the first 48 hrs after hospitalization.

It depends on the severity of the case.

 Causative agents of community-acquired pneumonia are s. pneumonia, h. influenza, Pseudomonas, Legionella, other gram-negative rods.

  1. pneumonia is the most common cause of CAP.

It affects human being younger than 60 yrs without comorbidity and 60 yrs and older with comorbidity.

  1. pneumonia is a gram-positive organism that is present in the upper respiratory tract. then they are become colonized and cause disseminated invasive infections like that it affects the otitis media and rhinosinusitis. S. pneumonia also causes lobar and bronchopneumonia in the patients.
  2. influenza is also a causative organism for community-acquired pneumonia. It affects older people with comorbid illnesses. (alcoholism, COPD, Diabetes Mellitus)

Mycoplasma pneumonia is caused by m. pneumonia. It is spread by infected respiratory droplets through person-to-person contact. It spreads out through the entire respiratory tract including bronchioles and has the characteristics of bronchopneumonia.

Viruses are the most common cause of pneumonia in infants and children.

In immunocompromised adults, cytomegalovirus is the most common viral pathogen.

HOSPITAL ACQUIRED PNEUMONIA

It is also called nosocomial pneumonia. In this case, the onset of pneumonia symptoms more than 48 hrs after the admission of a patient with no evidence of infection at the time of admission. the ventilator-associated pneumonia is also hospital-acquired.

Bacterial pneumonia is developed in a patient with acute respiratory failure ( who receives mechanical ventilation at least 48 hrs). The factors that may predispose pt to pneumonia

a.varieties of comorbid conditions

b. supine positioning

c. hypotension

d. metabolic disorders

e. prolonged hospitalization

The organisms that cause the HAP

a. Enterobacter species

b. E.coli

c. h. influenza

d. Klebsiella species

e. proteus

f. methicillin resistance staphylococcus aureus

PNEUMONIA IN IMMUNOCOMPROMISED HOST

It includes pneumocystis and fungal pneumonia, mycobacterium tuberculosis. it occurs with the use of corticosteroids, immunosuppressive agents, chemotherapy, nutritional delectation, use of broad-spectrum anti-microbial agents, aids, a genetic immune disorder.

organisms are

a. E.coli

b. enterobacteria

c.klebsiella

d. h. influenza

ASPIRATION PNEUMONIA

It is a pulmonary consequence resulting from the entry of endogenous or exogenous substances in the lower airway. It occurs in the community and hospital settings.

organisms are:

a. s. pneumonia

b. h. influenza

c. s. features

PATHOPHYSIOLOGY

  • the upper airway prevents the potentially infectious particles from reaching the sterile respiratory tract.
  • pneumonia arises from normal flora present in patients whose resistance has altered.
  •  Also occurs from bloodborne organisms that enter the pulmonary circulation and trapped the pulmonary capillary bed.
  • it affects both diffusion and ventilation.
  • as a result of which inflammation reaction occurs in alveoli, exudate formation interferes with the diffusion of oxygen and carbohydrate.
  • WBC, neutrophils, also migrate to the alveoli and fill the normally air-filled space.
  • areas of, lungs are not ventilated because of secretion of mucus and mucosal edema that cause partial occlusion of bronchi and alveoli.
  • This results in bronchospasm and hypoventilation
  • as a result of which fever, chills, pleuritic chest pain, dyspnea occurs.

RISK FACTORS

  • heart failure
  • diabetes
  • alcoholism
  • COPD
  • aids

CLINICAL MANIFESTATION

  • sudden onset of chills
  • fever
  • pleuretic chest pain
  • aggravated deep breathing and coughing
  • dyspnea
  • bradycardia
  • myalgia
  • pleuritic pain
  • pharyngitis

DIAGNOSTIC FINDINGS

  • pulmonary function test
  • blood culture
  • chest X-ray
  • physical examination
  • sputum examination

  

PREVENTION

  • pneumococcal  vaccine
  • staff education about infection
  • infection and microorganisms surveillance
  • prevention of transmission of microorganisms

modifying host resistance for infection