Pneumonia and its classification

Pneumonia and its classification

Hello students and friends, today we are going to discuss what is pneumonia and its classification with their signs and symptoms and causes.

Pneumonia is an inflammatory condition of the lungs affecting primarily the alveoli (microscopic air sacs).
The bacterium Streptococcus pneumonia is a common cause of pneumonia.
Pneumonia is usually caused by infection -viruses or bacteria.
Less commonly caused by other microorganisms, certain drugs, and other conditions such as autoimmune diseases.

SIGNS AND SYMPTOMS

    SYMPTOMS                                                        FREQUENCY

  

       COUGH                                                                  79- 91%

       FATIGUE                                                                    90%

       FEVER                                                                    71-75%

       SHORTNESS OF BREATH                                    65-75%

       SPUTUM                                                                 60-65%

       CHEST PAIN                                                           39-49%

The typical signs and symptoms in the children under 5years of age are:

Fever, Cough, and fast or difficult breathing.

• People have symptoms like productive cough, fever accompanied by shaking chills, shortness of breath, sharp or stabbing chest pain during a deep breath as well as their rate of breathing also gets increased in case of infectious pneumonia.
• In children less than 2 months, a cough is frequently absent.

More severe signs and symptoms may include:

• Blue tinged skin
• convulsions
• consciousness is decreased
• persistent vomiting
• temperature is increased
• thirst decreases

CAUSES OF PNEUMONIA:

• Pneumonia is primarily caused by bacteria or viruses.
• Streptococcus pneumonia is the common cause of pneumonia.
• Less commonly by fungi and parasites.

RISK FACTORS:

1. Smoking
2. Alcoholism
3. Asthma
4. COPD(Chronic Obstructive Pulmonary Disease)
5. Liver disease
6. Chronic Kidney Disease
7. Drugs including proton pump inhibitor or H2- blockers
8. Old age

Let's discuss bacteria, viruses, fungi, and parasites involved in causing pneumonia.

BACTERIA

• Bacteria are the main cause of community-acquired pneumonia(CAP).
• Streptococcus pneumonia is mostly involved in causing pneumonia.
• Nearly 50% of cases are caused by Streptococcus pneumonia.
• Other bacteria's involve in causing pneumonia are:

1. Haemophilus influenzae
2. Chlamydophilia pneumonia
3. Mycoplasma pneumonia
4. Staphylococcus aureus
5. Moraxella catarrhalis
6. Legionella pneumophilia
7. Gram-negative bacilli

• Pneumonia caused by Legionella may occur abdominal pain.
• Pneumonia caused by Streptococcus pneumonia is associated with rusty colored sputum.
• Pneumonia caused by Klebsiella has bloody sputum(hemoptysis).
• Mycoplasma pneumonia may occur in association with swelling of lymph nodes in the neck region, pain in the joints, or a middle ear infection.
• Alcoholism is associated with Streptococcus pneumonia, anaerobic organisms, and Mycobacteria tuberculosis.
• Smoking facilitates the effect of Streptococcus pneumonia, Haemophilus influenza, Moraxella catarrhalis, and Legionella pneumophilia.
• Streptococcus pneumonia is more common in winters.

VIRUSES

1. Rhinovirus
2. Influenza virus
3. Coronavirus
4. Adenovirus
5. Parainfluenza virus
6. Respiratory syncytial virus
7. Herpes simplex virus(rarely causes pneumonia)

• Cytomegalovirus pneumonia is mainly seen in patients with organ transplants.
• Influenza viruses may account for over half of all viral cases.
• Outbreaks of other viruses also occasionally occur, including coronavirus and hantavirus.

FUNGI

• Uncommon, but occurred in those individuals who have a weaker immune system due to any immunosuppressive drugs and AIDS.
• Fungi which cause pneumonia are:

1. Histoplasma capsulatum
2. Blastomyces
3. Cryptococcus neoformans
4. Coccidioides immitis

PARASITES

1. Toxoplasma gondii
2. Ascaris lumbricoids
3. Plasmodium malariae

• Parasites enter in the body through direct contact with the skin, or via insect (vector)
• Except for Paragonimus westermani, the most parasite doesn't affect especially lungs but they involve the lungs secondarily to other sites.
• Parasites cause eosinophilic pneumonia.

MECHANISM

In pneumonia, lung alveoli are filled with blood, so that the supply of oxygen gets hinders.

It frequently starts as an upper respiratory tract infection which then moves into the lower respiratory tract.

Let's discuss the mechanism of viral and bacterial pneumonia:

VIRAL:

• When people touch any contaminated object and then touch their eyes or nose then respiratory syncytial virus entered into the body.
• Some viral infections occur through contaminated airborne droplets that get inhaled by the nose or mouth.
• Once the virus entered into the upper respiratory tract and reaches the lungs, then the virus invades the cells lining the airways, lung parenchyma, or alveoli.
• Some viruses such as herpes simplex may reach the lung via blood.
• When viruses invade the lungs, varying degrees of cell death occurs.
• When the immune system starts responding to the infection, even more, lung damage may occur.
• Primarily WBC, mainly mononuclear cells, generates inflammation.
• Viruses that damage the lungs simultaneously affect other organs and thus body functions get disrupted.
• Viruses also make the body more susceptible to bacterial infections; in this way, bacterial pneumonia can arise as a co-morbid condition.

BACTERIAL:

• Most bacteria enter into the lungs via small aspirations of organisms residing in the throat or nose.
• Mycobacterium tuberculosis and Legionella pneumophila reach the lungs via contaminated airborne droplets.
• Bacteria can also spread via blood.
• Once bacteria enter into the lungs, it may invade the spaces between alveoli; where the macrophages and neutrophils (defensive WBC) attempt to inactivate the bacteria.
• The immune system gets activated by the release of cytokines through neutrophils. Then this leads to fever, chills, & fatigue.
• The neutrophils, bacteria, and fluid from the surrounding blood vessels fill the alveoli, resulting in the consolidation.

CLASSIFICATION OF PNEUMONIA

• It is most commonly classified by where/how it was acquired:

1. Community-Acquired Pneumonia ( CAP)
2. Healthcare-associated pneumonia
3. Hospital-Acquired Pneumonia (HAP)
4. Aspiration
5. Ventilator-Associated Pneumonia

• By the area of the lung affected:

1. Lobar Pneumonia
2. Bronchial Pneumonia
3. Acute interstitial pneumonia

• In children, classified on the basis of signs and symptoms:

1. Non-severe
2. Severe
3. Very severe

DIAGNOSIS

1. Chest X-Ray
2. Pulse oximetry
3. Chest radiograph
4. Blood test(CBC, Serum electrolyte, C- reactive protein)
5. Liver Function Test
6. CT- Scan
7. Culture for Mycobacterium tuberculosis
8. Sputum and blood cultures
9. Urine test - for antigens with culture or PCR(Polymerase Chain Reaction)
10. Physical examination

• Physical examination reveals low blood pressure, increased heart rate, decreased oxygen saturation
• Examination of the chest may be normal, but it may show decreased chest expansion on the other side and may show consolidation.
• Auscultation by stethoscope reveals the harsh sounds from the larger airways that are transmitted through the inflamed lung(bronchial breathing).
• Percussion may be dull over the affected area of the lung, its dullness increases in case of pneumonia.
• Vocal resonance distinguishes pneumonia from a pleural effusion.

MEDICATIONS

1. Amantadine
2. Levaquin
3. Azithromycin (Zithromax)
4. Rimantadine
5. Zanamivir

Hope you all find this helpful for you, if you have any query related to this topic or any other topic then you all are free to contact me via contact us or you can also ask your doubts on the comment box. Thank you! 

Disclaimer for https://physioworldblog.blogspot.com/ If you require any more information or have any questions about our site's disclaimer, please feel free to contact us by email at deepikajoshi12347@gmail.com. Disclaimers for Physioworld's blog All the information on this website - https://physioworldblog.blogspot.com/ - is published in good faith and for general information purpose only. Update Should we update, amend or make any changes to this document, those changes will be prominently posted here.