PREMID Flashcards
The most important function of the lungs is _____.
gas ex- change
- The diaphragm and thoracic muscles must be capable of expanding the thorax and lungs to produce a subatmo- spheric pressure.
- The airways must be unobstructed to allow gas to flow into the lungs and reach the alveoli.
- O2 and CO2 must be able to diffuse through the alveolar- capillary membrane.
- The cardiovascular system must circulate blood through the lungs and ventilated alveoli.
ability of the lungs to perform gas exchange
_______ can provide valuable information
about these important individual processes that support gas exchange.
Pulmonary function tests
Various _______ are available to aid in the diagnosis and assessment of pulmonary diseases, to determine the need for therapy, and to evaluate the effectiveness of respira- tory care.
measurements
For ________ , knowledge of these tests and the ability to interpret the measurements are essential for assessing patients objectively and for planning and imple- menting effective patient care.
respiratory therapists (RTs)
A complete evaluation of the respiratory system includes a ____
patient history, physical examination, radiographic imaging, arterial blood gas analysis, and tests of pulmonary function.
Although diagnostic ______ is performed in a laboratory setting and usually only on patients in a stable condition, RTs also perform many of these tests at the bedside on patients who are acutely ill or being evaluated for surgical readiness.
pulmonary function testing
There are three categories of pulmonary function tests, measuring ________123
(1) dynamic flow rates of gases through the airways,
(2) lung volumes and capacities, and
(3) the ability of the lungs to diffuse gases.
A combination of these measurements provides a quantitative picture of ______
lung function.
Although ______ do not diagnose specific pulmonary diseases, these tests identify the presence and type of pulmonary impairments and the degree of pulmonary disease present.
pulmonary function tests
Some basic tests of pul- monary function are often performed at the _____ to provide immediate information about the need for _______ and its effectiveness.
bedside / respiratory therapy
Generally, the primary purposes of pulmonary function testing are to identify ____ and _____
pulmonary impairment and quantify the severity of pulmonary impairment if present.
_____ has diagnostic and therapeutic roles and helps clinicians answer some general questions about patients with lung disease
Pulmonary function testing
• Is lung disease present?
• What type of lung impairment is present?
• What is the degree of lung impairment?
• Is more than one type of lung impairment present?
• Can multiple lung diseases be separated?
DIAGNOSTIC
• Is therapy indicated?
• What treatments are most effective?
• To what degree is the disease reversible?
• Can treatments be evaluated?
• Is rehabilitation feasible?
THERAPEUTIC
The indications for pulmonary function testing are as follows
• To identify and quantify changes in pulmonary function.
• To evaluate need and quantify therapeutic effectiveness.
• To perform epidemiologic surveillance for pulmonary disease.
• To assess patients for risk for postoperative pulmonary compli- cations.
• To determine pulmonary disability.
The most common purposes of pulmonary function testing are to detect the presence or absence of pulmonary disease, to classify the type of disease as either obstructive, restrictive, or both (mixed), and to quantify the severity of pulmonary impairment as mild, moderate, severe, or very severe. Over time, pulmonary function tests help quantify the progres- sion or the reversibility of the disease.
To identify and quantify changes in pulmonary function.
Pulmonary function tests may aid clinicians in selecting or modifying a specific therapeutic regimen or technique (e.g., bronchodilator medication, airway clearance therapy, reha- bilitation exercise protocol). Clinicians and researchers use pulmonary function tests to measure changes in lung func- tion objectively before and after treatment.
To evaluate need and quantify therapeutic effectiveness.
Screening programs may detect pulmonary abnormalities caused by disease or environmental factors in general popu- lations, in people in occupational settings, in smokers, or in other high-risk groups. In addition, researchers have deter- mined what normal pulmonary function is by measuring the pulmonary function of healthy people.
To perform epidemiologic surveillance for pulmonary disease.
Preoperative testing can identify patients who may have an increased risk for pulmonary complications after surgery. Sometimes the risk for complications can be reduced by preoperative respiratory care, or in some cases, the risk may be significant enough to rule out surgery.
To assess patients for risk for postoperative pulmonary compli- cations.
Pulmonary function tests can also determine the degree of disability caused by lung diseases, such as occupational asthma or coal workers’ pneu- moconiosis. Some federal entitlement programs and insur- ance policies rely on pulmonary function tests to confirm claims for financial compensation.
To determine pulmonary disability.
There are also contraindications to pulmonary function testing. Patients with acute, _________ should not be tested.
unstable cardiopulmonary problems, such as hemoptysis, pneumothorax, myocardial infarction, pulmonary embolism, and patients with acute chest or abdominal pain
Patients who have ___ and who have ____ should not be tested because there is a risk of aspiration.
nausea / recently vomited
Testing for patients who have had recent ______ should be delayed because changes in ocular pressure may be harmful to the eye.
cataract removal surgery
Pulmonary function testing requires patient ____ and ____
effort and cooperation.
Patients with ___ or ____ may not achieve optimal or repeatable results.
dementia or confusion
_____ should not be performed if valid and reliable results cannot be predicted.
Pulmonary function testing
In patients who are acutely ill or who have recently smoked a ciga- rette, the test validity of measuring the ______ may be hindered.
forced vital capacity (FVC)
Pulmonary function testing provides the basis for classifying pulmonary diseases into two major categories, ____ and ______
obstructive pulmonary disease and restrictive pulmonary disease.
These two types of lung diseases sometimes occur together as a mixed impairment.
obstructive pul- monary disease and restrictive pulmonary disease.
The primary problem in ______ is an increased airway resistance (Raw).
obstructive pulmonary disease
____ is the difference in pressure between the ends of the airways divided by the flow rate of gas moving through the airway
Raw
There is an inverse relationship between Raw and _____
flow rate V.
If the pressure difference is constant, a reduced flow rate indicates an _____.
increase in Raw
the ____ of the airways normally lessens slightly during expiration,
radius
_____ are usually measured during expiration.
flow rates
According to ______ , Raw is inversely related to the radius (r) of the airways
Poiseuille’s law
The most important point of this formula is that a small decrease in airway radius (or diameter) leads to exponential increase in the _____
airway resistance
_____ can be reduced by excessive contraction of the bronchial and bronchiolar muscles (bronchospasm), excessive secretions in the airways, swelling of the airway mucosa, airway tumors, collapse of the bronchioles, and other causes.
Airway radius
By measuring ______ pulmonary function tests measure Raw, estimate the size of the airways, and indicate the presence of obstructive disease.
flow rates
The primary problem in _______ is reduced lung compliance, thoracic compliance, or both.
restrictive lung disease
______ is the volume of gas inspired per the amount of inspiratory effort;
Compliance
____ is measured as the amount of pressure created in the lung or in the pleural space when the inspiratory muscles contract.
effort
_______is calculated according to the following formula:
C = ∆V / ∆P
Compliance
Anatomy affected
Obstructive Disease / Restrictive Disease
Obstructive Disease
- Airways
Restrictive Disease
-Lung parenchyma, thoracic pump
Breathing phase difficulty
Obstructive Disease / Restrictive Disease
Obstructive Disease
- Expiration
Restrictive Disease
- Inspiration
Pathophysiology
Obstructive Disease
Restrictive Disease
Obstructive Disease
-Increased airway resistance
Restrictive Disease
-Decreased lung or thoracic compliance
Useful measurements
Obstructive Disease
Restrictive Disease
Obstructive Disease
- Flow rates
Restrictive Disease
- Volumes or capacities
If the pressure difference is constant, a reduced inspi- ratory volume indicates a reduction in ______.
compliance
________ is usually the result of alveolar inflammation (pneumonia), swelling (pulmonary edema), or scarring (pulmonary fibrosis);
Reduced lung compliance
a _____ may be the result of thoracic wall abnormalities, such as kyphoscoliosis, or exogenous pressure exerted on the thoracic cavity, such as asci- tes or pregnancy.
reduced thoracic compliance
____ diseases also can result in reduced lung volumes and restrictive-type pulmonary impairments, mainly by affecting the function of the inspiratory muscles.
Neuromuscular
lung compliance and thoracic compliance may be normal, but the patient is unable to generate enough ______ pressure to take a _____
sub-atmospheric / full, deep breath.
Some _____ and some ______ also may affect the ability of the lung to diffuse gases.
obstructive diseases and restrictive diseases
In some dis- eases, there is damage to the alveolar-capillary membrane, or less alveolar surface area is accessible for diffusion. Measuring the _______ can identify the destruction of alveolar tissue or the loss of functioning alveolar surface area.
diffusing capacity of the lung for carbon monoxide (DLCO)
For each measurement of pulmonary function, there is a predicted ____ and _____
value and upper and lower limit of normal
It is expected that most healthy individuals would fall between the values of ___ and ___
LLN and ULN
The percent predicted value can be used to quantify ____
severity of impairment.
______ is generally regarded as a very low- risk procedure. However, there is potential to transmit infective microorganisms to ____ and _____
Pulmonary function testing / patients and technologists
Transmission can occur by
______
direct or indirect contact.
Standard precautions should be applied because of the potential exposure to ______ which can harbor potentially hazardous microorganisms.
saliva, mucus, or blood,
Patients with ____ or ______ pose the greatest potential hazard, and patients with ______ are at the greatest risk.
oral lesions or active respiratory infections / compromised immune systems
Practitioners should wear ____ when handling potentially contaminated mouthpieces, valves, tubing, and equipment surfaces.
gloves
When performing procedures on patients with potentially infectious airborne diseases, practitioners should wear a ____ or _____ , especially if the testing induces coughing.
personal respirator or a close-fitting surgical mask
Practitioners should always ______ between testing patients and after contact with testing equipment.
wash their hands
it is ____ to clean the interior surfaces of the testing instruments routinely between patients, the mouthpiece, nose clips, tubing, and any parts of the instrument that come into direct contact with a patient should be ______ between patients.
unnecessary / disposed, sterilized, or disinfected
Any equipment surface showing visible condensation from exhaled air should be _____ before reuse.
discarded, disinfected, or sterilized
When testing instruments are disassembled for cleaning and disinfecting, ______ should be considered and _____ may be necessary before testing resumes.
manufacturer recommendations / recalibration
The routine use of ______, in-line barrier filters is controversial.
low-resistance
____ may be appropriate when internal surfaces of manifolds and valves proximal to mouthpieces are inaccessible or difficult to disassemble for cleaning and disinfecting.
Filters
____ provide visible evidence to reassure patients that their protection has been considered.
Filters
_______ requires measurement of gas volume or flow, and various instruments and measurement principles are used to make these measurements.
Pulmonary function testing
There are two general types of measuring instruments: _____
instruments that measure gas volume and instruments that measure gas flow.
instruments that measure gas volume and instruments that measure gas flow. Both types of instruments simultaneously measure ____ , and both compute various ___ and ___ used in pulmonary function testing.
time / volumes and flow rates
The term _____ is sometimes used as a generic term for all volume-measuring and flow-measuring devices.
spirometer
Volume-measuring devices are specifically called______ and include water-sealed, bellows, and dry rolling seal types. These devices expand as they collect gas volumes.
spirometers
The magnitude of the expansion is the ____ measured,
volume
the speed of expansion represents the _____
flow rate
Flow-measuring devices are commonly called _____ , although some practitioners reserve this term for only the device originally designed by Fleisch. These devices measure flow using a variety of unique principles.
pneumotachometers
The Fleisch-type ______ measures the change in pressure as gas flows through it.
pneumotachometer
Known as _____ , another type of flow-measuring device measures the tempera- ture change created by gas flowing through it.
thermistors or mass flowmeters
There are also ____, which use rotation of a fan or blades similar to a windmill.
tubinometers
The _____ of an instrument refers to the range or limits of how much it can measure.
capacity
____refers to the accuracy of the instru- ment over its entire range of measurement, or its capacity.
Linearity
For tests of pulmonary function, these general principles should be considered:
test sensitivity and specificity, validity, and reliability.
_______ address the test’s ability to detect disease, or absence of it, respectively.
Sensitivity and specificity
_____ of the test relates to its meaningfulness or the ability to measure what it is intended to measure.
Validity
____ of the test is its consistency.
Reliability
Never report test results that are ______
invalid or unreliable.
______ —the measurement of air entering and leaving the lungs—includes measurement of several values of forced airflow and volume during inspiration and expiration.
Spirometry
the purpose of _____ is to assess the ability of the lungs to move large volumes of air quickly through the airways to identify airway obstruction.
spirometry
To a lesser extent, _____ can also identify and quantify a restrictive pattern of pulmonary disease.
spirometry
_____ is an effort-dependent test that requires careful patient instruction, understanding, coordination, and cooperation.
Spirometry
