Pneumonia is a respiratory disease characterized by inflammation of the alveoli.
The respiratory tract is composed of various organs with an internal cavity that allows the passage of air.
When we breathe in, the air flows through the following “tubes”:
- pharynx (pharynx),
- larynx (larynx),
- trachea (trachea),
- bronchioles (branches of the bronchi),
Alveoli are very small flexible sacs in the lungs:
- they expand when inhaled,
- they contract on exhalation.
The alveoli are surrounded by many capillaries to allow:
- that oxygen passes from the alveoli into the blood,
- that carbon dioxide from the bloodstream into the lungs
Pneumonia can be caused by:
- harmful microorganisms (viruses, bacteria, parasites or fungi),
- irritants (for example, smoke).
The respiratory tract has small hairs along the inner mucous membrane, which serve to transport these pollutants to the outside.
In addition, the cells of the respiratory tract generate mucus to promote the expulsion of microorganisms and harmful substances.
If these protective functions do not function correctly due to age or other changes in the mucosa, harmful substances can penetrate into the small alveoli.
In pneumonia, the alveoli fill with:
- inflammatory fluid,
► Children (the immune system is not yet sufficiently developed).
► Elderly people (the immune system is weakened).
► People with chronic illness.
► People with weakened immune systems due to:
- diseases, for example AIDS or a tumour (lymphoma, leukaemia, etc.),
- Taking medication for a long time, for example corticosteroids.
► Smokers, cigarette smoke harms the cilia located on the mucous membrane of the respiratory system. It also blocks the activity of macrophages (white blood cells) that protect the organism.
► People who have recently had an organ transplant.
► Convalescence after surgery.
Pneumonia is characterized by flu-like symptoms, which can be strong.
It can affect one or both lungs. In the latter case, it is called bilateral.
Protective mechanism against pneumonia
Normally, the lungs are in a sterile environment, but possible are:
- 1. temporarily inhaled micro-organisms;
- latent microorganisms (humans are healthy, but laboratory tests indicate the presence of microorganisms).
At the level of the upper respiratory tract (nasal cavity, pharynx, etc.), bacterial flora is important because it acts as a barrier against the entry of harmful microorganisms.
Local protection mechanisms
1) Mechanical mechanisms
Mucociliary system – mucus secretion is a very important cleansing mechanism.
The mucus contains substances with antimicrobial action, which:
- guarantee control over the microorganisms present,
- prevent the formation of severe infections.
Mucociliary cleansing refers to the simultaneous movement of cilia towards the mouth and nose to transport solid particles to the outside. This process is important to keep the respiratory system clean.
There are bacteria that are able to inhibit this process.
The result is a multiplication of these germs and also other, normally not harmful microorganisms, which, however, can become harmful in this situation.
Mechanisms that inhibit the descent of microorganisms are:
- epiglottis (closing of the epiglottis),
2) Immunological mechanisms
- Phagocytes, especially alveolar macrophages, represent an important defense, but are also the gateway of microorganisms such as Mycobacterium tuberculosis, Legionella pneumophila, Pneumocystis jirovecii, etc.
- Secretory IgA, however, some microorganisms have IgA proteases (a type of enzyme) and can therefore destroy these antibodies.
Types of pneumonia
This species is most common in children and in the elderly (over 65 years).
In children, the viruses responsible are, mainly:
- respiratory syncytial virus (RSV),
- influenza virus,
- herpes simplex virus,
In adults and the elderly, influenza viruses are the viruses that usually cause pneumonia.
The symptoms observed in viral pneumonia are mild and flu-like.
If the bacteria later enter the lungs, the patient develops serious symptoms.
Bacterial infections are more common in adults and the elderly.
Most bacterial pneumonia is caused by Streptococcus pneumoniae.
Viral pneumonia – Bacterial pneumonia
Type of patient: Personswith normal immune systems. A patient with a weakened immune system or hospitalized for other respiratory infections.
Therapy: Antibiotics do not help, the doctor can prescribe antivirals, The doctor can prescribe antibiotics.
Prognosis: Adolescents can recover within a week or two, older people and people suffering from other diseases need a few weeks. This can be life-threatening and lead to death. Is more aggressive and difficult to treat.
Causes of pneumonia
Pneumonia is mainly caused by:
Viral pneumonia is more common in children.
The bacterial cause is the most common and severe.
Sintomi della PolmonitePneumonia can occur as a result of other diseases such as:
- seasonal influenza.
Other causes of pneumonia:
- smoking (damaging the cilia of the respiratory tract),
- alcohol (changes the bacterial colonization in the mouth),
- Radiation and radiation therapy.
Risk factors of pneumonia
1) Decreased cough reflex: the cough reflex may be absent in:
- Diseases that prevent the closure of the glottis: paralysis of the recurrent laryngeal nerve, reclining tracheal catheter, etc.
- Insufficient contraction of the respiratory muscles due to neuromuscular diseases or serious changes in the chest.
2) Decreased mucociliary cleansing: Some factors can affect the movement of cilia, for example:
- viral infections of the upper respiratory tract (which can lead to necrosis of ciliary cells),
- Low temperature of inhaled air (cold leads to paralysis of mucociliary activity),
- The use of general anesthetics in surgical interventions (such drugs have a paralyzing effect on ciliary movements and inhibit the cough reflex).
3) Reduction of macrophage activity: There are conditions that impair the phagocytic abilities of the alveolar macrophage compartment, such as
- diabetes, in which there are functional changes in the phagocytic activity of cells (granulocytes and macrophages),
- Cigarette smoking
- Air pollution, which leads to overloading of cilia.
4) Alveolar ambience conditions: The alveolar ambience may become dry with fluid excretion at the interstitial or alveolar level, especially in acute or chronic left ventricular insufficiency (in which the left ventricle cannot pump enough blood).
Other rare risk factors:
Change in the physico-chemical properties of bronchial mucus, which adversely affects protective functions, for example:
- Increase in viscosity (as in cystic fibrosis, a hereditary disease in which the viscosity of all exocrine secretions changes).
- Reduction of secretory IgA (this can occur with congenital defects of this Ig class.)
Patients with immunosuppression or those taking corticosteroids or immunosuppressive medications
People who are generally susceptible to pneumonia:
- alcohol addicts,
- Elderly patients.
Contamination by extrapulmonary infection
Contamination of the blood flowing to the lungs is usually caused by Staphylococcus aureus, in patients:
- who inject drugs into the vein,
- with endocarditis,
- with infections caused by venous catheters.
Is pneumonia contagious?
Even though pneumonia is not a contagious disease, the viruses and bacteria that cause it could be transmitted to third parties by:
- direct contact,
- Inhalation of respiratory secretions.
The microbial agent can spread in the air by:
Symptoms of pneumonia
In most cases, patients show flu-like symptoms before pneumonia develops.
These are followed by:
The severity of symptoms varies depending on the age of the patient.
Chest pain is a common sign in all types.
Bacterial pneumonia: This condition is characterized by symptoms such as:
- High fever.
- Chest pain.
- Cough with viscous sputum of yellow or greenish color.
- Shortness of breath.
- Accelerated breathing.
- Extreme fatigue.
- loss of appetite.
- Mental confusion, sometimes elderly people have only coughing and confusion as the first sign of pneumonia.
- Blue discolored lips and fingernails, indicating a decrease in oxygen in the body.
Viral pneumonia: This infection is characterized by flu-like symptoms.
As a rule, it begins with:
If the disease is advanced, it leads to:
- Shortness of breath
- Cough with clear or whitish sputum.
With this disease, the risk of developing secondary bacterial pneumonia increases.
Diagnosis of pneumonia
The doctor can diagnose pneumonia by:
- Physical examination
- Review of anamnesis.
After that, auscultation of the lungs is done with the stethoscope to hear if there is fluid in the lungs.
Some people may require other examinations, including:
- Transcutaneous oximetry (a small device that measures oxygen saturation in the blood is placed on the finger),
- Blood test to measure the number of white blood cells. If these are elevated, this indicates an infection.
- Examination of sputum (sputum test). Allows detection of the bacteria causing the infection.
- CT or X-ray to confirm the infection or determine its extent. This does not make it possible to distinguish between viral and bacterial disease, but can indicate whether the patient has interstitial pneumonia, foreign body pneumonia or bronchopneumonia.
- pleural culture (the doctor uses a syringe to remove some fluid from the chest),
- Bronchoscopy – a control of the lungs using an endoscope.
The doctor must rule out other respiratory diseases, such as:
- lung tumor and metastases,
- pulmonary edema,
- Pulmonary embolism.
- Chronic obstructive pulmonary disease (COPD).
Treatment of pneumonia
As a rule, patients suffering from pneumonia can be treated at home. However, if there is a very severe or fulminant form, the doctor decides to hospitalize the patient in order to be able to provide him with further help.
- Fever is treated by giving aspirin or a nonsteroidal anti-inflammatory drug (NSAID). The active ingredients are helpful because they can:
- reduce hyperthermia,
- regulate body temperature.
Mild fever is not problematic, but if it rises very high, it can be dangerous.
- Cough medications are used to relieve the discomfort. These should only be taken after consulting the doctor.
There are few anti-cough drugs that regulate sputum. One risks an increase in nasal congestion.
- Treatment of pneumonia in the elderly is similar to the treatments listed above. If the person is over 65 years of age and suffers from respiratory diseases such as asthma, a lung abscess, septicaemia or any other chronic disease, the doctor may advise hospitalization.
- The medical researchers have led to the production of a vaccine that can be administered as a preventive measure. These compounds are given to infants to build and boost their immune systems.
If the immune system is weakened, pneumonia can recur.
Clinical course and mortality in bacterial pneumonia
- For pneumococci: low
- For Pseudomonas / Enterobacteriaceae: 60 %
- Viruses are less dangerous or deadly
The mortality rate is 12 per 100,000: this figure is not very high, but it is relevant and increases especially in older people, where there is a mortality rate of 70 per 100,000 diseases.