what is pneumonia? classification symptoms preventions and treatment of pneumonia.

PNEUMONIA:

DEFINITION :

Pneumonia is an acute inflammation of lungs parenchyma resulting  from  infection of alveoli and respiratory bronchioles , characterized pathologically by consolidation of lung parenchyma and clinically by fever , cough , dyspnea  and chest pain in most cases .

EPIDEMOLOGY:

·        Its is a common illness affecting approximately 450 million people a year and occurring in all parts of the world. It is a major cause of death among all age groups, resulting in 1.4 million deaths in 2010 (7% of the worlds yearly total)

·        It was the 4th leading cause of death in the world in 2016, resulting in 3.0 million deaths worldwide.

^·         Rates are greatest in children less than five and adults older than 75 years of age.

^·         It occurs about five times more frequently in the developing countries then developed countries.

·         Viral pneumonia accounts for about 200 million cases.

CLAASIFICATION  :

There are a number of classification based on etiologic agent , morphological  features  and health status of the individual .

A.    ETIOLOGICAL CLASSIFICATION ;

Bacterial                                                             80 – 90%

Streptococcus pneumonia                                   60 -75%

Mycoplasma pneumonia                                     5 – 18%

Haemophilis influenza                                        4 – 5 %

Legionella                                                           2 – 5 %

Chlamydia                                                          2 – 3 %

Staphylococcus aureus                                      1 – 5 %

Gram negative bacilli                                        rare

Anaerobes                                                          rare



Rickettsial                                                         1%

Coxiella burnetti 



Viral                                                                 10 – 20 %

Influenza                                                           8 %

Other viruses                                                     2 – 8 %

B.    CLINICAL CLASSIFICATION :

1 ) . COMMONLY ACQUIRED PNEUMONIA ;

·        It occur in previously healthy individual  .

·        Depending upon the causative organism , rapidity of onset , radiographic evaluation and laboratory finding this is further classified into typical and atypical pneumonia .

TYPICAL PNEUMONIA :

·         Onset  is rapid

·        Organisms:

§  Streptococcus pneumonia                                  

§  Haemophilis influenza                                      

§  Gram negative bacilli

·        Clinical features :

§  Fever

§  Cough

§  Pleuritic chest pain

     ATYPICAL PNEUMONIA :

·        Onset is slow

·        Organisms:

§  Mycoplasma

§  Chlamydia pneumonia

§  Viral pneumonia

·        Clinical features :

·        Fever

·        Cough   

2. HOSPITAL  ACQUIRED PNUEMONIA :

       Pneumonia that develop in hospital in a patient who has been admitted for more than 48 hours are considered hospital acquired pneumonia .

Organisms :

·        Staphylococcus pneumonia      10%

·        Gram negative bascilli             60%

·        Staphylococcus pneumonia      10 %

·        Anaerobes

3. ASPIRATION PNEUMONIA :

Aspiration of gastric content during seizures , coma  , anesthesia and other condition may lead to pneumonia called aspiration pneumonia .

Organisms:

·        Aerobic

·        Anaerobic

C.MORPHOLOGICAL CLASSIFICATION :

 1.LOBAR PNEUMONIA :

 The pneumonia that involves a large portion of or a complete lobe of lung homogenously is called lobar pneumonia .

 Organisms :

·        Staphylococcus pneumoniae ( most commonly )

·        Klebsiella staphylococci

·        H.influyneza

2. BRONCHOPNEUMONIA :

  This pneumonia is characterized by patch inflammation of lung parenchyma involving more than one lobe.

·        Organisms ;

o   Staphylococci

o   Streptococcal pneumonia

o   H.influenza

o   Psedumonas

·        Clinical features :

§  Shaking chills

§  High fever 

§  Productive cough

§  Rusty sputum

C.    CLASSIFICATION ACCORDING TO THE PATIENT PREVIOUS HEALTH STATUS

 1.PRIMARY PNEUMONIA :

Pneumonia that occur in previously healthy person is called primary pneumonia .

·        Organisms :

o   Mycoplasma

o   Chlamydia

o   Viruses

o   Coxiella burnetti

o   Pneumocystis carnii

2. SECONDRY PNEUMONIA :

Pneumonia occurring in a person who have underlying lung abnormality that     predispose them to pneumonia is called secondary pneumonia  such as COPD.

RISK FACTORS:

Pneumonia can affect anyone. But the two age groups at highest risk are:

·         Children who are 2 years old or younger

·         People who are age 65 or older

OTHER RISK FACTORS INCLUDE:

·         Being hospitalized. You're at greater risk of pneumonia if you're in a hospital intensive care unit, especially if you're on a machine that helps you breathe (a ventilator).

·         Chronic disease. You're more likely to get pneumonia if you have asthma, chronic obstructive pulmonary disease (COPD) or heart disease.

·         Smoking. Smoking damages your body's natural defenses against the bacteria and viruses that cause pneumonia.

·         Weakened or suppressed immune system. People who have HIV/AIDS, who've had an organ transplant, or who receive chemotherapy or long-term steroids are at risk.

COMPLICATIONS:

Even with treatment, some people with pneumonia, especially those in high-risk groups, may experience complications, including:

Bacteria in the bloodstream (bacteremia) :

·         Bacteria that enter the bloodstream from your lungs can spread the infection to other organs, potentially causing organ failure.

Difficulty breathing

·          If your pneumonia is severe or you have chronic underlying lung diseases, you may have trouble breathing in enough oxygen.

·          You may need to be hospitalized and use a breathing machine (ventilator) while your lung heals.

Fluid accumulation around the lungs (pleural effusion):

·          Pneumonia may cause fluid to build up in the thin space between layers of tissue that line the lungs and chest cavity (pleura).

·          If the fluid becomes infected, you may need to have it drained through a chest tube or removed with surgery.

Lung abscess. :

·         An abscess occurs if pus forms in a cavity in the lung. An abscess is usually treated with antibiotics.

·         Sometimes, surgery or drainage with a long needle or tube placed into the abscess is needed to remove the pus.

PREVENTION :

To help prevent pneumonia:

Get vaccinated :

·          Vaccines are available to prevent some types of pneumonia and the flu.

·         Talk with your doctor about getting these shots.

·         The vaccination guidelines have changed over time so make sure to review your vaccination status with your doctor even if you recall previously receiving a pneumonia vaccine.

Make sure children get vaccinated. :

·         Doctors recommend a different pneumonia vaccine for children younger than age 2 and for children ages 2 to 5 years who are at particular risk of pneumococcal disease.

·          Children who attend a group child care center should also get the vaccine.

·         Doctors also recommend flu shots for children older than 6 months.

DIAGNOSIS :

If  pneumonia is suspected, your doctor may recommend the following tests:

1.Blood tests :

·        Blood tests are used to confirm an infection and to try to identify the type of organism causing the infection.

·        However, precise identification isn't always possible.

2.Chest X-ray :

·        This helps your doctor diagnose pneumonia and determine the extent and location of the infection.

·        However, it can't tell your doctor what kind of germ is causing the pneumonia.

3.Pulse oximetry :

·        This measures the oxygen level in your blood.

·        Pneumonia can prevent your lungs from moving enough oxygen into your bloodstream.

4.Sputum test. :

·        A sample of fluid from your lungs (sputum) is taken after a deep cough and analyzed to help pinpoint the cause of the infection.

“ Your doctor might order additional tests if you're older than age 65, are in the hospital, or have serious symptoms or health conditions”

 These may include:

1.CT scan :

·         If your pneumonia isn't clearing as quickly as expected, your doctor may recommend a chest CT scan to obtain a more detailed image of your lungs.

2.Pleural fluid cultur :

·        A fluid sample is taken by putting a needle between your ribs from the pleural area and analyzed to help determine the type of infection.

TREATMENTS :

      Antibiotics

      Cough medicines

      Fever reducer / pain relievers .

REFERENCES :

1. https://www.mayoclinic.org/diseases-conditions/pneumonia/symptoms-causes/syc-20354204

2.https://www.lung.org/lung-health-and-diseases/lung-disease-lookup/pneumonia/symptoms-and-diagnosis.html

3.Textbook of pathology , 3^rd edition , written by ihsaan Danish , 153 page.