Respiratory
System Tests
Many laboratory, radiological, and surgical procedures are
utilized in the diagnosis and treatment of diseases of the
respiratory system. Following are brief summaries of some
of the procedures frequently used.
Arterial
Puncture
Arterial blood gas sampling measures how well the lungs are
functioning in delivering oxygen to blood and clearing carbon
dioxide from it as well as how efficiently the heart is as
a pump. In arterial puncture, a needle is inserted, usually
into the radial artery at the wrist, and a small amount of
blood is withdrawn. Because pressure is greater in arteries
than veins, pressure must be applied at the puncture site
for several minutes to be certain that bleeding has stopped.
In cases where frequent sampling is required, an indwelling
catheter or arterial line may be utilized. The arterial blood
sample is placed in a blood gas analyzer and checked for levels
of oxygen, carbon dioxide, and pH.
Bronchography
Bronchography is an x-ray of the trachea and bronchial tree
used to help locate obstruction, tumors, and cysts in the
bronchial tree. It is also used for guidance of the bronchoscope
during bronchoscopy. Local anesthetic is required for bronchography,
first with a spray and then via drip through a catheter passed
through the nose or mouth into the throat and down the trachea.
A catheter is used to administer contrast medium prior to
x-rays.
Bronchoscopy
Bronchoscopy allows for visualization of the trachea and
bronchial tree to check for tumors or foreign bodies, locate
bleeding sites, remove mucus or foreign bodies, or obtain
tissue or secretion specimens. It is utilized to diagnose
malignancy, tuberculosis, and pulmonary disease caused by
bacteria, fungi, or parasites. Local or general anesthetic
may be used. The bronchoscope is an endoscope which is designed
to pass through the trachea, allowing direct visual inspection
of the tracheobronchial tree. The flexible fiber optic bronchoscope
allows greater visualization than a rigid one and also decreases
risk of injury to the patient. A rigid hollow tube may be
used to remove foreign body or if a large biopsy sample is
required. Attachments to the bronchoscope allow suctioning
of mucus, injection of saline to wash inner surfaces, and
brushing to obtain cell samples from mucous lining.
Laryngoscopy
This procedure allows direct visualization of the interior
of the larynx for detection of foreign bodies, tumors, and
other abnormalities. The laryngoscope is similar to the bronchoscope;
however, it does not enter as far into the body. A direct
laryngoscopy is performed with a laryngeal speculum or laryngoscope.
Indirect laryngoscopy is done with a mirror.
Pulmonary
Function Test
The pulmonary function test (PFT) is used to determine the
cause of shortness of breath and the presence of disease or
injury. It is used for presurgery testing and to evaluate
disability. Nose clips prevent air from escaping through the
nostrils. The patient breathes into a flexible tube (spirometer).
The PFT tests various breathing patterns such as normal breathing,
exhaling as rapidly as possible after inhaling normally, or
inhaling and exhaling deeply. During PFT patients may also
breathe specific quantities of helium, nitrogen, or pure oxygen.
Lung Scan
There are two types of lung scans. Ventilation and perfusion
is used to detect infection, pulmonary emboli and tumors,
and to evaluate emphysema. The second type is perfusion scan
in which an isotope is mixed with a gas and inhaled.
Mediastinoscopy
Mediastinoscopy allows direct visualization of tissues and
organs behind the sternum. It is used to detect and evaluate
infections and various types of malignancies. General anesthesia
may be utilized for this procedure. A small incision is made
in the chest for insertion of the mediastinoscope. Specimens
may be collected for analysis.
Thoracentesis
This procedure is used to obtain samples of fluid from the
cavity between the lungs and chest wall in order to diagnose
malignancy, tuberculosis, and blood and lymphatic disorders.
It is also utilized to relieve pressure caused by the accumulation
of excess fluid in this area. Thoracentesis is done with the
patient seated, leaning forward, and bent over in order to
provide as much room as possible between the ribs for insertion
of the needle.
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Chronic
Obstructive
Pulmonary Disease
Chronic obstructive pulmonary disease (COPD) is a "generic"
term used to describe conditions that lead to airway obstruction.
These conditions include chronic obstructive asthma and bronchitis,
chronic bronchitis with emphysema, and emphysema. A major
contributing component of COPD is aggravation by environmental
factors. The respiratory systems of those with COPD have undergone
significant changes, resulting in limitations on the lungs’
ability to function.
Chronic bronchitis is
characterized by increased mucus secretion by the tracheobronchial
tree. A chronic productive cough is usually present for at
least three months of two consecutive years. Other diseases
that might account for these symptoms--such as bronchiectasis,
tuberculosis, and tumor--must be excluded prior to the diagnosis
of chronic bronchitis. In chronic bronchitis, the airways
have become narrowed and partially clogged with mucus, resulting
in continual difficulty of breathing. The principal pathologic
change is hypertrophy and hyperplasia of the mucus-secreting
glands of the trachea, bronchi, and bronchioles. Smoking is
associated with irritation of airways, causing narrowing of
airways and paralysis of cilia.
Chronic bronchitis is treated with bronchodilators and anti-inflammatory
drugs delivered via inhaler. Oxygen may also be administered.
Antibiotics are used for bacterial infections. Atrovent delivered
by inhalation blocks nerves in the airway, helping to reduce
cough.
Emphysema is defined
by the American Thoracic Society as "abnormal permanent
enlargement of air spaces distal to terminal bronchiole, with
destruction of their walls and without obvious fibrosis."
Emphysema reduces the normal elasticity of the lung that helps
hold airways open. As a result of impairment of elasticity,
the inflating lung does not pull the airways open. With progression
of inelasticity, the small airways of the lung collapse on
expiration, making it impossible to fully exhale "stale"
air.
Smoking is one of the major causes of emphysema. Air pollution
also contributes. An imbalance in lung chemistry can also
be responsible in the development of emphysema. A lack of
alpha1-antitrypsin allows protease, a disease-fighting
enzyme, to destroy lung tissue.
Emphysema is gradual in onset. In the beginning stages the
patient has severe colds each winter for a few years, accompanied
by heavy cough which persists and becomes chronic. In some
instances, chronic bronchitis is present. As the disease progresses,
slight morning and evening difficulties worsen until breathlessness
interferes with daily activities. As the lungs become less
able to inhale and exhale and exchange gases, normal activity
becomes impossible. Emphysema can lead to serious cardiovascular
complications as it interferes with passage of blood through
the lungs and into circulation. The heart must work harder,
causing enlargement which may eventually lead to heart failure.
Coding
If a diagnosis of chronic obstructive pulmonary disease is
given, the record must be reviewed to see if a specific condition
causing the lung obstruction can be identified. Note must
also be made whether the COPD is associated with an acute
condition. If the specific form of COPD and the presence of
acute exacerbation can be verified, 496, Chronic airway
obstruction, not elsewhere classified, should not be used.
Both the Alphabetic and Tabular Index of ICD-9-CM must be
utilized for selection of the most specific code possible.
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Respiratory System
Tests
Chronic Obstructive
Pulmonary Disease
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