Pulmonary Diagnostic Testings (Mod 1) Flashcards
what are diffusion capabilities?
How thick is the a/c membrane, how hard is it to cross (or loss of surface area)
What do Pulmonary Function Tests (PFTs) measure?
- Flows and volumes
- Compliance and resistance
- Diffusion Capabilities
What is the purpose of Pulmonary Function Tests (PFTs)?
A test used to assess potential lung disease, the following are used to increase effectiveness of assessment
- Use Pt history
- Use ABG analysis
- Use cxr
- Help to determine degree of pulmonary impairment
- Help determine type of pulmonary disease (restrictive or obstructive)
Purpose of Pulmonary Function Tests (PFTs)? (5 )
- Identify and quantify change in pulmonary function due to disease
- Evaluate effectiveness of therapy
- perform epidemiological studies for pulmonary deisease
- Assess pt for risk of post op complications
- Determine pulmonary disability (how much they have)
What are 2 major categories of pulmonary disease?
Obstructive and restrictive
Main characteristics of obstructive disease?
Slide 7
main charactersitics of restrictive diseases?
slide 7
What are 2 general types of measuring devices?
- Those that measure volume
- Those that measure flow
What are volume measuring devices called?
Spirometers, these can also measure flow
What are flow measuring devices commonly called?
pneumotachometers
What variables do every measuring device have?
Slide 8
What is a Spirometer?
A device that measures volume or flow
- can be falsified by whether they measure lung volumes or airflow
Add shit from slide 9, 11,12,14,16,17, 26 (summarized slide),27
What are thermal flow meters?
- how do they work?
Have wires that are temp sensitive
- Operates on principles that as gas passes over the heated wire the sensor cools and changes its resistance
- change in resistance is proportional to the gas flow past it
- only good for unidirectional flow
What are common flow measuring devices?
What is the definition of accuracy in relation to Pulmonary Function Tests (PFTs)?
Closeness of agreement between teh results of a measurement and the true value.
- how close is the actual to the calibrated value when setting up the machine
What are 3 important elements of Pulmonary Function Tests (PFTs) testing?
- Accuracy
- Repeatability
- Reproducibility
What does repeatability mean in relation to Pulmonary Function Tests (PFTs)?
Closeness of agreement between the results of successive measurements carried out with the same conditions
What does reproducibility mean in relation to Pulmonary Function Tests (PFTs)?
Closeness of agreement between results of successive measurements carried out with changed conditions
Indications for Pulmonary Function Tests (PFTs)?
- Assess the potential effects or response to environmental or occupational exposure
- assesses risk for surgical procedures known to affect lung function
- assess impairment and/or disability
What are the AARC guidelines and indications for Pulmonary Function Tests (PFTs)?
To quantify severity of known lung disease
- to detect presence or absence of lung dysfunction suspected by other factors (s&s)
- assess the change in lung function over time as well as effectiveness of treatments (progression)
Contraindications for Pulmonary Function Tests (PFTs)?
Most contraindications for relative and time based. most involve post posing test until the reason is more beneficial with less risks
- High pressures generated in the thorax impact those pressures have on abdominal/thoracic organs/tissues
- Large BP changes affecting variou body tissue
- Chest wall/lung expansion
- communicable diseases
Hazards/complications of Pulmonary Function Tests (PFTs)?
- pneumothorax;
- Increased intracranial pressure;
- syncope, dizziness, light-headedness;
- chest pain;
- paroxysmal coughing;
- contraction of nosocomial infections;
- oxygen desaturation due to interruption of oxygen therapy;
- bronchospasm
Pt considerations for Pulmonary Function Tests (PFTs)?
Can be physically demanding, so the stress must be considered (what if the pt has suboptimal lung conditions)
- Chest/abdominal pain of any cause
- Oral or facial pain exacerbated by mouthpiece
- stress incontinence
- Demential or confusional state
Ideal patient position for Pulmonary Function Tests (PFTs)?
Sitting, standing, or supine
- position needs to be reported
- supine spirometer done for neuromuscular disease
- sitting preferable for saftey bc of potential syncope
- ideally chair would have arms and no wheels
What are pt considerations for Pulmonary Function Tests (PFTs) if the pt is standing?
Have chair close by
- may be preferred when testing obese pts (larger volumes/flows may be achieved)
- Testing is to be performed over long periods of time, the same position should always be used
Why is age, sex, height, and weight taken into considerations for Pulmonary Function Tests (PFTs)?
Could effect reference values selection and calc
- transgender pts use sex at birth
- Ethnicity is also important to note bc lung development and function is affected
How would deformities affect Pulmonary Function Tests (PFTs)?
The span from the middle finger tip to middle fingertips is used as an estimate of height (w/equation)
When should medications be taken/used for Pulmonary Function Tests (PFTs)?
It depends (add info from slide 32)
What does methacholine?
Causes bronchospasm and irritates the airway
- done on purpose to dx condition
- it is used in conjunction w/Ventolin to see if the impairment is reversible
Subject preparation for Pulmonary Function Tests (PFTs)?
- what should be avoided
Avoid the following, it needs to be reported if any of the following are a concern
- Avoid Smoking/vaping within at least 1hr of testing
- Avoid consuming intoxicants within 8hrs of testing
- Avoid vigorous exercise within 1hr of testing
- Wear clothing that could restrict full chest/ab expansion
- Eating large meals within 2hrs of testing
Lab details that need to be required to ensure the accuracy of Pulmonary Function Tests (PFTs) equipment?
All of the following are recorded daily for calculations, during calibration procedure
- Temperature
- Barometric pressure
- Relative humidity and time of day are important
- Time of day
Direct contact risk factors for transmissions of infection?
Mouthpieces or pneumotachometers, the following concerns would be associated with
- saliva
- oral mucosa
- bleeding gums
Indirect contact risk of infection during Pulmonary Function Tests (PFTs)
Aerosol and droplet
Prevention of transmission for Pulmonary Function Tests (PFTs) (infection control)?
Use disposable filters (mouthpieces) and nose clips where possible
- disposable filters, small changes in R, but not major effect on flow rates or volumes have little effect on diffusion tests
Minimal quality control for Pulmonary Function Tests (PFTs)
Record calibration procedures, recording, and record keeping
- Log of calibration results
- Documentation of repairs or alterations to equipment
- Date of computer software/hardware updates
What is the most important calibration we need to worry about on the daily for quality control of Pulmonary Function Tests (PFTs)?
volume calibration and calibration checks are performed via 3L calibration syringe
What are 3 common Volume Measuring Devices?
The following measuring using Volume Displacement
- Water sealed spirometer
- Bellows spirometer
- Dry rolling seal spirometers
What are 3 types of Flow Measuring Devices?
- Thermal (hot wire anemometer)
- Turbine flow meter
- Pneumotachographs (pressure differential and ultrasonic)
How is gas flow calculated in Thermal Flowmeters?
Calculated from the amount of power needed to maintain the temperature of the element. Changes are gathered via:
- Heated wire
- Thermistor bead
How do Heated wires in Thermal Flowmeters work?
- what variables are affected and monitored?
Cooling results in decreased resistance
- Higher gas flow -> cools -> Decreases resistance -> less power needed to maintain temp
- There is a inverse relationship between gas flow and power
How to Thermistor Beads work in Thermal flowmeters?
- What variables are affected and monitored?
Cooling results in increased resistance
- higher gas flow -> cools -> increases resistance -> more power needed to maintain temp
- Direct relationship between gas flow and power
How do Turbine Flowmeters function?
Uses a rotating vane or turbine to measure gas flow
- The vane turns at a rate dependant on the flow of the gas
- only good for unidirectional flow
- Flow is measured by counting the number of times the vane turns and can be done (mechanically and electronically)
In a Turbine flowmeter, how is flow mechanically measured?
Works by linking the vane to a needle which is attached to a calibrated display
In a Turbine flowmeter, how is flow electronically measured?
Works by using a light beam that is interrupted each time the vane turns
How do Ultrasonic Pneumotachograph measure flow?
Use struts which create a partial obstruction to gas flow, as gas flows by the struts, vortices are formed
- The ultrasonic transmitter produces sounds waves which are interrupted by the vortices
- Interruptions are counted by the receiver and are equivalent to s a specific volume
Information to Obtain from Pt Prior to Testing (All tests) 8
- Name, identify correct pt
- Age + date of birth - ensure date of birth entered calculates the correct age
- Height and weight - if the pt cannot stand for height, or if the pt has severe kyphoscoliosis, consider
substituting arm span measurement for approximation of height (tip of middle finger to tip of middle
finger) - Gender - biological
- Race
- Smoking history, time of last cigarette. Food consumption and time of last meal. Medication use and
time of last use. - Medical history pertinent to the test (see contraindications section) + recent illness
- Other info that can alter test results
Attaining this info is important for accurate results of testing.
Activities to Avoid Prior to PFT (Subject Preparation)? 6
- Smoking/vaping within 1 hour
of the test - Eating a large meal 2 hours
prior to testing - Avoid intoxicants 8 hours prior
to testing - Vigorous exercise within 1 hr of
test - Wearing restrictive clothing
during the test - No short acting inhaled drugs 4 hours prior, oral therapy and any
LABA should not be taken 12 hours prior to testing - for reversibility
testing.
