Pneumonia and its treatment -1


What is pneumonia?
How do people "catch pneumonia"?
What are pneumonia symptoms?
Physical examination
How is pneumonia diagnosed?
Organisms cause pneumonia

Quinolones: Past, Present, and Future

Adverse effects

What are the organisms that cause pneumonia?


The Lung

  • The Lung
  • The lung is the essential respiration organ in air-breathing animals, including most tetra pods, a few fish and a few snails. The most primitive animals with a lung are the lungfish (vertebrate) and the pulmonate snails (invertebrate). In mammals and the more complex life forms, the two lungs are located in the chest on either side of the heart. Their principal function is to transport oxygen from the atmosphere into the bloodstream, and to release carbon dioxide from the bloodstream into the atmosphere.
    This exchange of gases is accomplished in the mosaic of specialized cells that form millions of tiny, exceptionally thin-walled air sacs called alveoli.

    Medical terms related to the lung often begin with pulmo-, from the Latin pulmonarius ("of the lungs"), or with pneumo- (from Greek πνεύμω "breath")

What is pneumonia?

  • Pneumonia
  • Pneumonia fills the lung's alveoli with fluid, keeping oxygen from reaching the bloodstream. The alveolus on the left is normal, while the alveolus on the right is full of fluid from pneumonia. Pneumonia is an inflammatory illness of the lung.Frequently, it is described as lung parenchyma/alveolar (microscopic air-filled sacs of the lung responsible for absorbing oxygen from the atmosphere) inflammation and (abnormal) alveolar filling. Pneumonia can result from a variety of causes, including infection with bacteria, viruses, fungi, or parasites, and chemical or physical injury to the lungs. Its cause may also be officially described as idiopathic, that is unknown, when infectious causes have been excluded.

Prior to the discovery of antibiotics, one-third of all people who developed pneumonia subsequently died from the infection. Currently, over 3 million people develop pneumonia each year in the United States. Over a half a million of these people are admitted to a hospital for treatment. Although most of these people recover, approximately 5% will die from pneumonia.

How do people "catch pneumonia"?
Some cases of pneumonia are contracted by breathing in small droplets that contain the organisms that can cause pneumonia. These droplets get into the air when a person infected with these germs coughs or sneezes. In other cases, pneumonia is caused when bacteria or viruses that are normally present in the mouth, throat, or nose inadvertently enter the lung.
During sleep, it is quite common for people to aspirate secretions from the mouth, throat, or nose. Normally, the body's reflex response (coughing back up the secretions) and immune system will prevent the aspirated organisms from causing pneumonia.
However, if a person is in a weakened condition from another illness, a severe pneumonia can develop. People with recent viral infections, lung disease, heart disease, and swallowing problems, as well as alcoholics, drug users, and those who have suffered a stroke or seizure are at higher risk for developing pneumonia than the general population.

Once organisms enter the lungs, they usually settle in the
air sacs'Pulmonary alveolus, informally known as an air sac, one of innumerable spherical outcroppings of the respiratory bronchioles in the mammalian lung, the primary sites of gas exchange with the blood'
of the lung where they rapidly grow in number. This area of the lung then becomes filled with fluid and pus as the body attempts to fight off the infection.

What are pneumonia symptoms?
Most people who develop pneumonia initially have symptoms of a cold which are then followed by:
  • High fever (sometimes as high as 104 degrees Fahrenheit),
  • Shaking chills
  • Cough with
    sputum'matter, as saliva mixed with mucus or pus, expectorated from the lungs and respiratory passages.'
    production. The sputum is usually discolored and sometimes bloody.

Patients may become:
  • Short of breath
  • Chest pain may develop if the outer aspects of the lung are involved. This pain is usually sharp and worsens when taking a deep breath, known as pleuritic pain.
In other cases of pneumonia, there can be a slow onset of symptoms. A worsening cough, headaches, and muscle aches may be the only symptoms. In some people with pneumonia, coughing is not a major symptom because the infection is located in areas of the lung away from the larger airways. At times, the individual's skin color may change and become dusky or purplish (a condition known as
cyanosis'Cyanosis is a blue coloration of the skin and mucous membranes due to the presence of deoxygenated hemoglobin in blood vessels near the skin surface. It occurs when the oxygen saturation of arterial blood falls below 85-90% (1.5g/dl deoxyhemoglobin)'
) due to their blood being poorly oxygenated.
Children and babies who develop pneumonia often do not have any specific signs of a chest infection, but develop a fever, appear quite ill, and can become lethargic.
Elderly people may also have few symptoms with pneumonia.

Physical examination
Persons with symptoms of pneumonia need immediate medical evaluation.

Physical examination by a health care provider may reveal:
  • Fever
  • Sometimes low body temperature
  • An increased respiratory rate
  • Low blood pressure
  • Fast heart rate
  • Low oxygen saturation, which is the amount of oxygen in the blood as indicated by either pulse oximetry or blood gas analysis.
    People who are struggling to breath, who are confused, or who have cyanosis (blue-tinged skin) require immediate attention.

Pneumonia as seen on chest x-ray
  • X- Ray
  • A: Normal chest x-ray.
    B: Abnormal chest x-ray with shadowing from pneumonia in the right lung (white area, left side of image).
    Listening to the lungs with a stethoscope (auscultation) can reveal several things.
    A lack of normal breath sounds, the presence of crackling sounds (rales), or increased loudness of whispered speech (whispered pectoriloquy) can identify areas of the lung that are stiff and full of fluid, called "consolidation".
    The examiner may also feel the way the chest expands (palpation) and tap the chest wall (percussion) to further localize consolidation.
    The examiner may also palpate for increased vibration of the chest when speaking (tactile fremitus).

How is pneumonia diagnosed?
Pneumonia may be suspected when the doctor examines the patient and hears coarse breathing or crackling sounds when listening to a portion of the chest with a stethoscope. There may be wheezing, or the sounds of breathing may be faint in a particular area of the chest. A chest x-ray is usually ordered to confirm the diagnosis of pneumonia.

Sputum samples:
Can be collected and examined under the microscope. If the pneumonia is caused by bacteria or fungi, they can often be detected by this examination. A sample of the sputum can be grown in special incubators, and the offending bacteria can be subsequently identified. It is important to understand that the sputum specimen must contain little saliva from the mouth and be delivered to the laboratory fairly quickly. Otherwise, overgrowth of no infecting bacteria may predominate.

A blood test:
A complete blood count may show a high white blood cell (WBC) count, indicating the presence of an infection or inflammation. In some people with immune system problems, the white blood cell count may appear deceptively normal. Blood tests may be used to evaluate kidney function (important when prescribing certain antibiotics) or to look for low blood sodium. Low blood sodium in pneumonia is thought to be due to extra anti-diuretic hormone produced when the lungs are diseased (SIADH).

Specific blood serology tests for other bacteria (Mycoplasma, Legionella and Chlamydophila) and a urine test for Legionella antigen are available. Respiratory secretions can also be tested for the presence of viruses such as influenza,
respiratory syncytial virus'Human respiratory syncytial virus (RSV) is a negative-sense, single-stranded RNA virus of the family Paramyxoviridae, which includes common respiratory viruses such as those causing measles and mumps.'
adenvirus'Adenoviruses are medium-sized (90–100 nm), nonenveloped (naked) icosahedral viruses composed of a nucleocapsid and a double-stranded linear DNA genome.'

Is a procedure in which a thin, flexible, lighted viewing tube is inserted into the nose or mouth after a local anesthetic is administered. The breathing passages can then be directly examined by the doctor, and specimens from the infected part of the lung can be obtained.
Sometimes, fluid collects in the pleural space around the lung as a result of the inflammation from pneumonia. This fluid is called a pleural effusion. If the amount of this fluid that develops is large enough, it can be removed by inserting a needle into the chest cavity and withdrawing the fluid with a syringe in a procedure called a thoracentesis. In some cases, this fluid can become severely inflamed (par pneumonia effusion) or infected (emphysema) and may need to be removed by more aggressive surgical procedures.