Introduction Flashcards
has a large amount of functional reserve.
pulmonary system
can result in a significant degree of pulmonary dysfunction
injury or illness
can severely limit the length or quality of an individual’s life
pulmonary dysfunction
in these forms, pulmonary disorders can cause death within minutes
acute
can take years before resulting in an individual’s death, but many of those years may be spent with serious disability and a poor quality of life.
chronic disorders
pulmonary disorders must be ___?
detected and treated at the earliest possible time.
plays a significant role in modern health care
pulmonary function testing
used to assess the integrated function of the structures that comprise the thoracic/pulmonary system.
pulmonary function testing
structures of the thoracic/pulmonary system
- lungs
- air passages serving the lungs
- thoracic abdominal structures that surround the lungs
lungs are composed of:
- parenchyma
- vasculature
entire lobe of the lungs
parenchyma
area of the lungs capable of gas exchange
parenchyma
composed of blood vessels, blood
vasculature
air passages serving the lungs are composed of:
- upper respiratory tract
- lower respiratory tract
upper respiratory tract includes:
- mouth
- nose
- larynx
lower respiratory tract includes:
- trachea
- mainstem bronchi
- all intrapulmonary airways
thoracic/abdominal structures that surround the lungs include:
- pleura
- support structures of the thoracic wall
- muscles of ventilation and controlling nerves
- abdominal contents
lung, cavity, and space between chest
pleura
covers the outer surface of the lungs
visceral pleura
forms the lining of the thoracic cavity
parietal pleura
support structures of the thoracic wall include:
- ribs
- sternum
- costal cartilages
- thoracic vertebrae
how many pairs of ribs?
12
muscles for normal inspiration
- inner intercostal muscle
- diaphragm
muscles for normal expiration
no muscles, lungs recoil naturally
muscles for forceful inspiration
SUPAS Sternocleidomastoid Upper Trapezius Pectoralis Major Anterior, Middle Posterior Scalene Serratus APS
muscles for Forceful expiration
ASI
Abdominal muscle
Serratus API
Internal Intercostal muscle
controlling nerves that keep the diaphragm alive
c3, c4, c5
the additional volume of air that the lungs can inhale and exhale when breathing to the limit of capacity in times of stress
pulmonary reserve
can cause measurable abnormalities in pulmonary function.
dysfunction of one or more of the thoracic/abdominal structural components
a reduced ability to move air into and out of the lungs because of?
airway resistance problems
key method used for evaluating and managing pulmonary disorders.
pulmonary function testing
three basic factors that can, either individually or in some combination, contribute to a person having a limited tolerance for physical activities:
Poor conditioning.
The presence of a pulmonary dysfunction.
The presence of a cardiovascular dysfunction.
Limitations caused by pulmonary or cardiovascular dysfunction may be improved, at least to some degree, through the use of
therapeutic measures.
can be used both to detect the presence of dysfunction and to monitor
a subject’s progress in either improving conditioning or benefiting from treatment.
cardiopulmonary stress testing
indications include:
medical diagnosis
surgery-related evaluation
disability evaluation
public health/research
medical diagnosis includes:
- determination of the presence of a disorder.
- Assessment of thane degree to which pulmonary function or exercise tolerance is affected by injury or disease.
- determination of the pathologic nature of a disorder.
- planning of therapy required for treating and managing a disorder
- evaluation of the therapeutic effectiveness of medical intervention for a disorder (bronchdilator therapy)
- monitoring the progression of a disorder (primary pulmonary disorders, neuromuscular disorders).
surgery-related evaluation include:
- Preoperative risk assessment (anesthesia /surgical procedure).
- postoperative assessment of the effects of thoracic surgery.
disability evaluation include:
-rehabilitation (to monitor the effects of a rehabilitation program on the progress
of a disorder).
-Insurance (documentation of baseline function or changes in function).
-Legal (doocumentation for Social Security, personal injury lawsuits, etc.)
public health/research includes:
- epidemiologic survey
- general or specific data accumulation
The most extensive studies of functio and exercise tolerance are performed in
hospitals in a laboratory setting
other settings where pft can be performed
- The bedside, either in a general patient-care setting or in an critical-care area.
- a physician’s clinic
- The workplace or other non-health care setting such as a shopping mall, school, etc.
often provide the first indication that an individual is experiencing some degree of dysfunction
Tests performed in non-health care settings
plays a significant role in the activities of a pulmonary function
laboratory.
specialized equipment
are instruments used to measure the volumes of air that are inhaled and exhaled during breathing
spirometers
published a paper on the use of water-sealed spirometer to measure vital capacities in 1846
john hutchinson
his work formed a basis for identifying pulmonary tuberculosis before it was clinically symptomatic
john hutchinson
spirometers can be classified as functioning by one of two possible operating principles:
primary volume measuring (PVM) spirometers
primary flow measuring (PFM) spirometers
the volume of air moving into and/or out of the subject’s lungs is measured directly
primary volume measuring spirometers
Air flow rates must be determined indirectly.
PVM spirometers
air flow rates may be determined by measurements on a graphic tracing of the spirometer’s movement during the breathing maneuver.
some PVM spirometers
Air flow rates can also be determined by electronic systems linked to the spirometer.
PVM spirometers
Air flow rates can also be determined by ??? linked to the spirometer
electronic systems
directly measure the flow rate of the inhaled and/or exhaled air.
PFM spirometers
Volume must be determined indirectly
PFM spirometers
Electronic systems are generally used to calculate volumes because?
air flow rates can change significantly during a single breathing maneuver.
cannot easily be performed manually
volume determinations
fv loop sign of obstructive?
scooping
fv loop sign of restrictive?
small loop
3 components
Lung volumes and Capacities
Airway Mechanics
DLCO
are measured independently
lung volumes
derived from two or more lung volumes
lung capacities
It is the amount of air that can be forcibly inhaled after a normal tidal volume
inspiratory reserve volume (irv)
irv amount
3100 mL
It is the volume of air that can be exhaled forcibly after exhalation of normal tidal volume.
Expiratory Reserve Volume(ERV)
erv amount
1200 mL
It is the volume of air remaining in the lungs after maximal exhalation.
Residual Volume(RV)
lung volume that can’t be measured normally
residual volume
can measure residual volume
nitrogen washout
helium dilution
body plethysmography
RV amount
1200 ml
It is the amount of air that can be inhaled or exhaled during one respiratory cycle
Tidal Volume(TV)
tv amount
500 ml
It is the maximum volume of air that can be inhaled following a resting state.
Inspiratory capacity(IC)
irv + tv
Inspiratory capacity(IC)
Inspiratory capacity(IC) amount
3600 ml
It is the amount of air remaining in the lungs at the end of a normal exhalation.
Function Residual Capacity(FRC)
erv + rv
Function Residual Capacity(FRC)
frc amount
2400 ml
It is the total amount of air exhaled after maximal inhalation.
Vital Capacity(VC)
TV+IRV+ERV
vital capacity
It is the maximum volume of air the lungs can accommodate
Total Lung Capacity(TLC)
vc amount
4800
tlc amount
6000 ml
lung capacities that cannot be measured by simple spirometry
FRC
TLC
ability to perform inhalation and exhalation
airway mechanics
normal action of the diaphragm
piston motion
movement of diaphragm during inspiration
downward, outward
movement of diaphragm during exhalation
upward, inward
dlco meaning
diffusing capacity of the lungs for carbon monoxide
ability of the lungs to perform gas exchange
DLCO
PVN spirometers are of two categories
- volume-collectinglvolume-dispiacement spiromeeters
- flow-through spirometers.
PVM spiroineters used iri the laboratory are generally
volume-collecting or volume-displacement devices.
the subject’s expiratory air moves into the spirometer, and his or her inspiratory air moves back out from it.
volume-collectinglvolume-dispiacement spirometers
Volume collecting or volume-displacement spirometers may be of
water-sealed
dry-sealed
beflows type
measures air as it passes completely through.
flow-through PVM spirometer
Volumes are not collected within the device.
flow-though
The only spirometer of this category is the rotor/turbine spirometer.
flow-through
The only spirometer of this flow-through is the
rotor/turbine spirometer.
consist of a double-walled, stationary cylinder that has water between the double walls
Water-sealed spirometers
is suspended above and inside the stationary cylinder of ws spirometer
freely moving cylindrical bell
serves as an airtight, low-friction seal for the bell.
water
It ensures that spirometer movement is in exact proportion to subject breathing volumes.
water
The spirometer bell moves downward as the subject ??? and upward as the subject ???.
inhales, exhales
can be simple or very complex systems
water-sealed spirometers
may have only a single breathing tube connected to the spirometer
simple system
Their use is limited to single-breath volume/flow studies
simple systems
with a double tube, one-way breathing arrangement
complex systems
can be used for studies that involve prolonged breathing on the spirometer.
complex systems
Spirorneter bells are available in different sizes, ranging from ??? of volume.
7 to 14 liters
determines the distance that the bell will need to move in response to a given breathing volume
bell diameter
small-diameter bells travel a ??? distance than do larger bells
greater
When volume determinations are made from a direct spirometer tracing, this ??? must be included in the calculations.
bell factor
there have been two configmations for watersealed spirometers
chain-compensated spirometer
Stead-Wells spirometer
was the first spirometer to be used
chain-compensated spirometer
It was originally designed with a light-weight metal bell, although today it is available with a plastic bell.
chain-compensated spirometer
is suspended from a chain that is looped over a pulley
counterweight
In simple models, a pen attached to the counterweight may be used
to make ??
spirograms
used to make spirograms
kymograph
may experience dizziness because carbon dioxide may be rebreathed
simple systems
no separate instrument for exhalation
simple systems
is very accurate for simple volume measurement.
chain-compensated
with breathing maneuvers that include rapid respiratory rates or rapid changes in air flow rates, some accuracy is lost
chain-compensated
lost accuracy in chain-compensated due to the mass of the bell and counterweight and their resulting ??
inertia
may not change in immediate response to changes in the subject’s breathing.
Spirometer movement
The use of ?? on more modern units somewhat reduces this inertia.
plastic bells
was developed in response to the inertia problems exhibited by the chain-compensated configuration
stead-wells spirometer
a system with better frequency response and better response to rapid flow rate changes
stead-wells
spirograms can be made with a pen attached directly to the spirometer bell.
stead-wells
very rugged and dependable
water-sealed spirometers
because of their size must be used primarily as stationary laboratory systems
water-sealed
Either??? or ??? may be used to make spirograms
mechanical recording systems
electronic recording system
some volume measurement error can occur if there are ?? in the system.
Leaks
what produces system leaks in water-sealed
Damage to the tubing system or bell or inadequate water levels in the spirometer
With the chain-cmpensated type of spirometer, volume measurement
error can also result when mechanical problems cause
resistance to the movement of chain
They consist of a rod-mounted piston within a cylinder
dry-sealed
ds spirometer ?? is made of plastic or a lightweight metal.
piston
Because it is designed to move ???, the piston does not
require a counterweight mechanism
horizontally
chain compensated spirometer inspiration, bell ??, pen ??
down, up
stead-well, bell up, pen ??
up
A pen for spirogram tracings can be attached to the
piston rod
is used to make the system airtight.
silicone plastic (silastic) rolling seal
consists of a tube that is approximately the same diameter as the piston/cylinder.
silicone plastic (silastic) rolling seal
The ?? is fastened to the inner wall of
the cylinder.
”outside” free end of the seal
The ?? is attached to the edge of the piston.
”inside” free end
Maintenance of ?? is less of a problem than it is for water-sealed spirometers.
dry-sealed spirometers
may cause resistance to piston movement.
mechanical malfunctions
are constructed of a flexible plastic material that is designed to collapse in folds.
bellows spirometers
unfolds and expands with the subject’s expiration and collapses with his or her inspiration.
bellows
There are two possible bellows designs
fully expanding bellows
wedge-shaped bellows
opens and closes like an accordion
fully expanding bellows
fully expands only along one edge, similar to the opening and closing of a book
wedge-shaped bellows
Smaller, more portable units generally make use of a bellows that expands
up and down vertically
Larger, primarily laboratory-based systems use bellows that expand
back and forth horizontally.
can offer the same accuracy as other PVM spirometers.
Large, horizonta1Iy expanding bellows systems
Little routine maintenance is required.
bellows spirometers
can cause the bellows folds to be more resistant to expanding
Collection of dirt and moisture within the bellows or aging of the bellows material
can occur in the bellows over time
cracks and tears
provide an excellent measure of breathing volumes.
Volume-collecting/volume-displacement devices
may be a source of error with rapid changes in air flow rates or subject respiratory rates.
inertia of their moving physical components
Laboratory-based systems of this type are used to perform complex tests that
involve prolonged subject breathing on the spirometer.
Volume-collecting/volume-displacement spirometers
Recording systems for PVM spirometers can be either
mechanical or electronic.
involve the movement pen along one axis and paper movement
along the perpendicular axis
mechanical systems
can be fastened to a rotating drum or may be moved linearly.
paper
is attached to the bell/piston/bellows
pen
electronic systems use a
potentiometer
positioned to rotate in response to movement of the bell/piston/bellows
potentiometer
the resulting electrical signal can be used to produce tracings by
the means of
electronic recorder
The air that leaves the subject is at
btps, body temperature and pressure
the only type of PVM spirometer that allow the measured air to pass completely through the device as the volume is measured.
rotor spirometers
The most frequently used rotor spirometer configuration is
wright-type spirometer
Measurement is based on the rotation of a rectangular, vanelike rotor
rotor spireometers
rotor spirometer Measurement is based on the
rotation of a rectangular, vanelike rotor
The rotor consists of a very thin, lighteight metal blade.
rotor
Measurement through the device is ?? because of how the slots and rotor blades are arranged.
unidirectional
Volume measurement by rotor spirometers is similar to the operation of a
turnstile
The instruction manual of one spirometer states that the rotor makes ?? for each liter of air passing through the chamber.
150 revolutions
Measurement error can result from ?? in rotor spirometers.
inertia of the mechanical components
Damage to the rotor can occur when flow rates exceed
300 l/min.
are limited primarly to handheld use at the bedside for measurement of unforced breathing maneuvers
rotor spirometers
Measurement of a ?? with a rotor spirometer can result in damage to the rotor
forced expiratory maneuver
provide a direct measurement of air flow rates.
PFM (primary flow measuring) spirometers
The flow-rate measurement can then be integrated electronically, on the basis of ???, into a volume measurement.
time
The different types of PFM spirometers
differential-pressure pneumotachometers
thermal anemometers
ultrasonic sensor spirometers.
have a flow-resistive structure (element) in the path of the gas stream
Differential-pressure pneumnotachometers
They function on the basis of how changes in air flow rates through the element affect upstream/downstream pressure relationships within the device
Differential-pressure pneurmotachometers
in differential pneumotachometer, ?? is greater than ??
p1, p2
As air flow rates increase, the difference between PI and P2 ???
also increases.
is used to measure the pressure difference within the device.
differential-pressure strain gauge transducer
is produced by the pressure transducer
DC analog electrical signal
Changes in the electrical signal are ??? to changes in the air flow rate.
directly proportional
V = AP/R
poiseulle’s law
This relationship is true only if air flow through the sensor is
laminar
This helps prevent condensation within the device from moisture in the subject’s exhaled air
spirometer sensor is heated to approximately body temperature
sensor makes use of a corrugated metal element.
fleisch-type/ fleisch style
2 types of differential pressure pneumotachometers
fleisch
lilly
most widely used PFM
differential pressure pneumotachometer
air flow rate is measured on the basis of how it affects the temperature of a heated element
thermal anemometer
The element is general;y a platinum wire or small metal bead that produces no resistance to air flow
thermal anemometer
used to keep the element at a fixed temperatre in termal anemometer
electrical current
Increases in electrical current are ?? to increases in air flow
rates within the sensor
directly proportional
is seriously affected by the humidity and temperature of the gas.
flow measurement by anemometers
Accuracy may also be affected by physical characteristics of the gas,
such as density
generally limited to unidirectional air flow measurement with separate inspiratory and expiratory sensors
anemometers
use a beam of ultrasonic sound waves to measure air flow
ultrasonic sensor spirometers
The beam detects a special type of gas stream turbulence called a
vortex
s are produced by a baffle in the gas stream with the ultrasonic sensor located
downstream from it.
vortices
Flow measurement in uss is based on an electronic count of the
pulses from the gas stream.
PFM spirometer sensors must be ?? in order for flow measurement to be accurate
laminar
designed to only measure peak expiratory flow rate (pefr)
dedicated peak flow meters
The main component is generally a movable vane, disk, or sphere
dedicated peak flow meter
two types of plethysmography systems.
Body plethysmography
Inductive plethysmography
requires that the subject’s entire body be enclosed within a boxlike cabinet during testing.
body plethysmography
involves the use of sensors strapped around the subject’s thorax and abdomen.
The equipment is smaller and less complicated
inductive plethysmography
used for making two kinds of pulmonary function measurements.
body pleth
. This can be used to determine total lung capacity
intrathoracic gas volume
body pleth 2 function measurements
intrathoracic gas volume
airway resistance
three types of direct measurements made with a Body pleth
- Inspiratory and/or expiratory air flow rakes during the subject’s breathing cycle.
- Air volume changes inside the sealed cabinet that result from expansion and contraction of the subject’s thorax.
- Changes in air pressure at the subject’s mouth.
are used to reflect changes in lung volume.
Cabinet air volume changes
Mouth pressure changes, when the subject’s airway is mechanically obstructed, are interpreted as
changes in alveolar pressure
Readings of mouth (alveolar) pressure compared against
changes in cabinet air volume are used to determine
lung volume.
cabinet air volume changes compared against subject ventilatory air flow rates are used to determine
airway resistance.
The cahinrt has a volume of approximately
600 liters
In newer, well-designed models, the cabinet is constructed
largely of
plexiglass.
This allows for good visibility of the subject. It also reduces any
claustrophobia that may be experienced by the subject.
plexiglass
used for measuring ventilatory air flow rates that can vary with the brand of
plethysmograph used
pneumotachometer
when activated, occludes the mechanical airway of the pneumotachometer
shutter
it is used to measure pressure at the mouth
pressure transducer
There are two very different methods for measuring body
pleth cabinet volume changes.
nonconstant-volume plethysmography cabinet
constant-volume, variable-pressure plethysmography cabinet.
referred to as volume- or flow-type plethysrmographs.
nonconstant volume pleth
These systems directly measure quantities of air that are forced to enter and leave the cabinet.
nonconstant-volume pleth
have a pressure transducer connected to an opening in the cabinet wall.
constant-volume, variable-pressure plethysmograph
pressure-type pleth
constant-volume, variable-pressure plethysmograph
The transducer directly measures changes in cabinet pressure during subject breathing.
constant-volume, variable-pressure plethysmograph
Some systems have a small leak built into the cabinet to allow for temperature
equilibrium
recording system is an important BP component
biaxial (x-y) recorder with a very good frequency response.
used to make indirect measurement of ventilatory parameters
respiratory inductive plethysmographs (rips)
They allow the operator to determine breathing volumes without a
physical connection to the subject’s airway
rips
This is done by evaluating the changes in thoracic and abdo~~al girth that the subject experiences during breathing
rips
rips are measured by a
rib-cage strap (RC) and an abdominal strap (AB)
The straps consist of ?? that are coiled like a te~ep~o~ie receiver cord.
teflon-insulated wires
produces a magnetic field around the wires
alternating current
resistance in the current flow through wires
inductance
The RC strap is placed around the subject’s
chest with its upper border just below the axilla.
The AB strap is placed at the
umbilical level with its upper border just below the rib cage
may be easier to use than a standard spirometer with infants, subjects on mechanical ventilation, sleeping subjects, and small animals
RIPS
need frequent calibration to maintain accuracy
RIPS
are often used in spirometer systems to control the movement of gas flow through the system.
Directional breathing valves and directional control valves
T- or Y-shaped valves that are used at the subject connection of a spirometer breathing circuit
directional breathing valves
have three gas flow ports, and the subject’s mouthpiece is attached to one of them.
directional breathing valve
Well-designed directional breathing valves must
- Have a low resistance to inspiratory and expiratory air flow.
- Have a small deadspace volume to minimize rebreathing of previously exhaled air.
- Be relatively easy to clean after use
The purpose of the directional breathing valve is
to separate the direction of the subject’s inspiratory air flow from the direction of the expiratory air flow.
are similar in their purpose to traffic signals
Directional control valves
They permit control and changes in the direction of gas flow within the
breathing circuit.
Directional control valves
used to direct the flow at different times as needed during a test io different portions of the breathing circuit
Directional control valves
are often necdcd when more complex tests are performed with a spirometer system.
Directional control valves
simple dcv systems controlled
manually by technologist
complex systems dcv controlled
computer
