Download Pneumonia DRAFT Nov. 02, 2016 Pneumonia is an infection of one

Pneumonia
DRAFT
Nov. 02, 2016
Pneumonia is an infection of one or both of the lungs caused by bacteria, viruses, fungi, or chemical
irritants. Pneumonia is basically inflammation of lung tissue effecting gaseous exchange in the
patient.
Types of pneumonia
1.
Bronchial pneumonia
Also known as bronchopneumonia; affects the tubular structures of the respiratory tree. The
anterior-ventral (A-V) areas of either lungs may be affected. By definition rhinitis, laryngitis,
pharyngitis, tracheitis, bronchitis or bronchiolitis can become pneumonia when the infectious process
extends into the alveoli level of the respiratory tree. Gravity results in the migration of infectious
material into the A-V areas of the lungs. The Bronchial descriptive term reflects the route of viral or
bacterial access to the lung.
Most often bronchial pneumonia occurs in a lobar pattern affecting one or more sections (lobes) of
the lungs. In quadruped animals the A-V lobules and lobes are the areas that are first affected due to
proximity; but much larger areas of the lungs can become involved as the infectious materials fill the
lungs in untreated or neglected cases. Occasionally bronchopneumonia can initially affect the lungs
diffusely as a result of inhalation of fine particulates. The most common example if diffuse
bronchopneumonia is dust pneumonia.
Dyspnea results from interference with normal oxygenation of venous blood and excretion of carbon
dioxide waste gas. Filling of the bronchioles and alveoli with exudate results in loss of normal gas
exchange in the effected lung tissue. As bronchioles and alveoli fill with inflammatory exudate the
lung becomes wet, heavier, and firmer than normal, and is referred to as “pulmonary consolidation”.
Consolidation is sometimes referred to by pathologists as “hepatization”. Hepatization means that the
lung feels firm like liver instead of being soft and compressible. This is caused by replacement of air
in the alveoli with exudate.
2.
Pleural Pneumonia
Also sometimes referred to as Fibrinous Pneumonia in large animal veterinary medicine, is the
result of extension of an infectious process from the lung into the pleural space. This is a sporadic
pleuritis that will be seen, resulting from the same micro-organism that is causing the pulmonary
pathology. Inflammation or damage to the pleural surface will result in accumulation of exudate and
excessive amounts of pleural fluid. Often large masses and sheets of fibrin may accumulate in the
pleural cavity. If not treated; the fluids and fibrin will compress the lungs, preventing normal lung
expansion and respiratory function. The affected animal may die as a result of asphyxiation.
Contagious bovine plueuropneumonia (CBPP) is caused by: Mycoplasma mycoides mycoides.
CBPP is an exotic foreign animal disease that is not present in the US. Signs and postmortem findigs
are similar to that described above. Anytime that one see a case of pleural pneumonia it should be
cultured and Mycoplasma sp. culture should also be included in the culture request.
3.
Interstitial pneumonia
Interstitial pneumonia is a type of pneumonia that is primarily inflammation of lung interstitial
tissue instead of respiratory epithelial tissue. The route of access to the lung may be via the
respiratory tree, or it may be hematogenous. Common causes are influenza viruses (BRSV virus in
cattle.
Food origin toxins (overconsumption of l-tryptophan, an amino acid that is converted into 3
methyl indole a respiratory toxin (atypical interstitial pneumonia).
Moldy feeds can cause allergic conditions which present as interstitial pneumonia (heaves in
horses). Toxic gas inhalation, such as is nitrogen dioxide, produced by fermenting silage. In humans
it is referred to as silo filers disease. Cattle housed in buildings adjacent to fermenting silage can also
be affected.
Etiologic Agents
Viruses
Bacteria
Mycoplasma
Fungi
Dust
Toxins
Gasses
Allergens
What are the symptoms of pneumonia?
The observed symptoms of pneumonia include:
 Fever
 Depression, apprehension and decreased mentation
 Weakness
 Rapid respiration that worsens with activity
 Loss of appetite
 Hypoxia, shortness of breath, and a resulting rapid respiratory rate occurs with
bronchopneumonia or pleuropneumonia
 Difficult expiration or “Expiratory Dyspnea” occurs with interstitial pneumonia
 Nasal discharge
serous with viral infection
purulent with bacterial infection
 Hypoxia and pale or bluish mucous membranes
 Rapid pulse
 Ocular discharge, especially with viral respiratory disease
 In horses, coughing is a frequent symptom with upper and lower airway disease and with
interstitial pneumonia, such as Heaves
 In cattle, coughing occur most commonly with early upper respiratory disease. It can also be
a symptom with interstitial pneumonias such as:
BRSV, PI3,
Atypical Interstitial Pneumonia
Pulmonary Emphysema
Fog Fever
Symptoms of pneumonia caused by viruses are very similar to bacterial pneumonia, note the
characteristics of the nasal discharge for a clue to the microbial origin. Mycoplasma pneumonia has
somewhat different symptoms, which include a severe cough that may produce mucus.
Diagnosis
Usually made based on your recent health history (such as surgery, a cold, or travel exposures) and
the extent of the illness. Based on these factors, your health care provider may diagnose pneumonia
simply on a thorough history and physical exam, but the following tests may be used to confirm the
diagnosis:
Diagnostic tests
Chest X-ray. This test takes pictures of internal tissues, bones, and organs, including the lungs.
Ultrasonography
Blood tests. This test may be used to see whether infection is present and if infection has spread to
the bloodstream (blood cultures). Arterial blood gas testing checks the amount of oxygen in your
bloodstream.
Sputum culture. This test is done on the material that is coughed up from the lungs and into the
mouth. It's often used to see if there's an infection in the lungs.
Pulse oximetry. An oximeter is a small machine that measures the amount of oxygen in the blood. A
small sensor is taped or clipped onto a finger. When the machine is on, a small red light can be seen
in the sensor. The test is painless and the red light does not get hot.
Chest CT scan. This imaging procedure uses a combination of X-rays and computer technology to
produce sharp, detailed horizontal, or axial, images (often called slices) of the body. A CT scan shows
detailed images of any part of the body, including the bones, muscles, fat, and organs. CT scans are
more detailed than regular X-rays.
Bronchoscopy. This is direct exam of the bronchi (the main airways of the lungs) using a flexible
tube (called a bronchoscope). It helps to evaluate and diagnose lung problems, assess blockages, and
take out samples of tissue and/or fluid for testing,
Pleural fluid culture. In this test, a sample of a fluid sample taken from the pleural space (space
between the lungs and chest wall). A long, thin needle is put through the skin between the ribs and
into the pleural space. Fluid is pulled into a syringe attached to the needle and sent to the lab where
it’s tested to find out which bacteria is causing the pneumonia.
Treatment
Prevention