Spirometry

Physical Description
1. Age
2. Height or Span. Without . Multiply by to get cm
3. Gender
4. Weight
5. Race

3.

History
Inquire about:
Mine / work
Mill
Farming
Gas / Fume exposure
Dusty

Smoking History
Differentiate between cigars, pipes and
Pack
Does pt still

Medical / Surgical History
Disease: , TB, Chronic , Recurrent Colds, pneumonia, infections
Record presence of: Hay / allergies

Withholding Medications
SABA: hrs
LABA: hrs
Methylxanthines: hrs
Slow Release Methylxanthines: hrs
Anticholinergics: hrs
Cromolyn Sodium: - hrs
Other Meds: Inquire about Inhaled steroids, cardiac meds, antibiotics, beta blockers

Vital Signs
RR: -
HR: -
BP: 120/80
Sensorium: Alert, oriented and able to follow

Other Respiratory Modalities:
Evaluate O2 , aerosol , pulmonary
Contraindications:
within 24 hrs, unstable , unable to
Prohibited activities
No alcohol within hrs, no exercise within minutes, don't wear clothing, don't eat large meal within hours.

Other considerations:
Room , barometric , dentures stay in unless they are , wear nose clips, sitting position

Testing:

Slow Vital Capacity (SVC):
Max after a inspiration
L or mL corrected to
ATPS x = BTPS
BTPS is based on: ambient , Barometric , Humidity

Measures:
Vital
Volume
Inspiratory Volume
Expiratory Volume

Slow Vital Capacity ATS Standards
End Level of breaths before SVC must not vary more than mL
Large Variances may indicate a
At least 2 acceptable maneuvers within % or L
SVC should be within % of best FVC
SVC higher than FVC indicates disease, but evaluate pt effort

Vital Capacity (VC)
Max then max
Typical Value: 4800 mL
decreased with restrictive disease
VC = + Vt + ERV
VC = IC +
VC = TLC -

Tidal Volume (Vt)
Normal resting breathing voume
Typical value: 500 mL
Decreased with restrictive disease
Vt x RR =
Vt - - IRV
Vt = VC - IRV -
Vt = TLC - - ERV - RV

Inspiratory Reserve Volume (IRV)
Largest volume of air that can be inspired above VT
Typical Value 3100 mL
Decreased with restrictive disease
IRV = IC -
IRV = VC - - Vt

Expiratory Reserve Volume (ERV)
Largest volume of air that can be expired from end level
Typical Value: 1200 mL
Decreased with restrictive diseases
ERV = - IC
ERV = FRC -

Inspiratory Capacity (IC)
Largest Volume of air that can be inspired from resting end level .
Typical Value 3600 mL
Decreased with restrictive disease
IC = + Vt
IC = VC -
IC = - FRC

Forced Vital Capacity (FVC):
Max inspiration followed by a expiration
If SVC FVC suspect obstructive disease
If SVC FVC question pt effort
Exhale until a volume pleateau OR seconds
Modified maneuver: After seconds, relax and exhale gently.

FVC Measurements:
Peak Expiratory Flowrate (PEFR)
Maximum achieved during FVC
10 L/s
Nonspecific in significance because it is very dependent on effort
Measured in L/s ATPS corrected to BTPS

Forced Expiratory Flow 200-1200
Average flowrate that occurs during FVC after the first mL has been expired
Typical: 6 L/s
Significance: Measures airflow in airways. Decreased with mechanical airway problems and disease, can be decreased d/t poor effort

Forced Expiratory Flow 25%-75%
Average flowrate during the half of FVC
Typical: 4-5 L/s ATPS corrected to BTPS
Significance: Measures flow in the airways, is in obstructive disease. Most sensitive to detect airway disease. Can appear erroneously if FVC and FEV1 are greatly increased in post bronchodilator studies.

Forced Expiratory Volume/Time (FEVtime)
Volume Expired of time interval
Common: FEV.5, FEV1, FEV2, FEV3, FEV6
ATPS corrected to BTPS
Significance: Decreased flows indicate obstructive disease, FEV1 used to assess improvement in post BD studies, allow 10-15 minutes in between pre/post tests.

FEVT / FVC%
Forced expiratory volume for time interval expressed as a percentage of total FVC
Minimum acceptable values:
FEV.5/FVC = %
FEV1/FVC = %
FEV2/FVC = %
FEV3/FVC = %
FEV6/FVC = %
Significance: with obstructive disease, with restrictive.

FVC to Generate Flow-Volume Loop
A forced expiratory maneuver followed by forced inspiratory maneuver
Recorder plots flow () and volume () for inspiration and expiration
Expiration is baseline, inspiration baseline
Important to coach max effort without
PEF is measured with pt at
PIF is measured with pt at
Forced Expiratory Flow at 25%, 50%, and 75% of VC
% is amount of that has been exhaled
Decreases in FEF50% and FEF75% indicate disease
These values can be more sensitive in detecting small airway obstruction than FEV1.

Forced Inspiratory Flow at 25%, 50% and 75% of Inspiratory Vital Capacity
Measured on inspiratory side of loop
useful when compared to expiratory Values for determining a site of large - particularly the % value
Maximum Forced Expiratory Flow (FEFmax)
Highest flow achieved on expiratory curve
Analagous to
FEFmax used to determine

Flow Volume Studies:
FEF50%/FIF50%
Ratio of forced expiratory flow to forced inspiratory flow at 50% of VC
Helpful in evaluating obstruction
Normal: -
Variable Extrathoracic Obstruction ratio >
Variable intrathoracic obstruction ratio <
Fixed airway obstruction would cause equally reduced flows
Formula: FEF50% / FIF50%

Fixed Airway Obstruction:
Appears as decreased FEF50% and decreased FIF50% with values approximately .
Example: Tracheal

Variable Extrathoracic Obstruction:
Appears as expiratory flows with inspiratory flows
FEF50% / FIF50% is >
Example: paralysis

Variable Intrathoracic Obstruction
inspiratory flows with expiratory flows
FEF50% / FIF50% is <
Ex: Tumor near the carina

Flow Vol. Loops
Restriction:
Decreased lung with flows
Loop is and

Asthma:
Increase in resistance in airways causes a in expiratory flows
out portion on expiratory loop

Emphysema:
Increased small airways along with loss of = a reduction of expiratory flows more pronounced than asthma

Pre/Post Bronchodilator testing:
Determines degree of obstruction
Indications:
FEV1 <%, cough of unknown , asthma, suspected hyperresponsiveness

Loops can be superimposed to readily detect improvement
SABA is given via MDI, SVN, or IPPB
FEV1 must improve by at least % and L to be considered reversible.
Forumla: (post FEV1 - pre FEV1) / pre FEV1 = % change
If FVC increases in post, it is suggestive of

Spirometry Evaluation:
2 Major characteristics that Spirometry measures: Lung &
Decreased indicate obstructive disorder.
CBABE: , , ,

Decreased indicates restrictive disorder
Neuromuscular: Myasthenia Gravis, Gullian Barre, Muscular Dystrophy
Cardiovascular: CHF
Pulmonary: pneumonia, atelectasis, pulmonary fibrosis
Trauma: head trauma, rib fractures, flail chest

Interpretation:
>= % Predicted : Normal
<% Predicted: Mild dysfunction
<% Predicted: Moderate dysfunction
<% predicted: Moderate/severe dyfunction
<% Predicted: Severe Dysfunction
<% predicted: Very Severe Dysfunction

FVC: ATS Standards
Maximal effort and smooth curve
Minimum of seconds effort or second plateau
Start of test needs to be with no hesitation
3 acceptable tests
Best Test has the highest +
Adults should stand or sit
Coughing shows as an upward deflection
Early termination is a short horizontal line at end of expiration
Back extrapolation % = (back extrapolated vol / FVC) x 100

Spirogram acceptability:
Free from artifact: No or glottis closure in 1st seond. No early . No variable effort. No leak. no obstructed mouthpiece.
Good Start: Extrapolated volume of <% of FVC OR time to PEF less than ms
Satisfactory Exhalation: 6 seconds and or volume plateau, reasonable duration or plateau, OR subject cannot continue to exhale.

Maximum Voluntary Ventilation
Largest Volume of Air inhaled and exhaled over a second period
Value is extrapolated to 1 minute and reported in L/min corrected to BTPS
Typical : L/m
Provides info about: status of muscles, compliance of and , airway
Pt Breathes as DEEPLY and as RAPIDLY as possible for 12 seconds
Significance: Large reductions = sever obstruction.
Effort dependent: If FEV1 x > MVV - question pt effort

Obstructive Spiro Results: FVC, FEV1/FVC
Restrictive Spiro Results: FVC, FEV1/FVC

Pediatric Spirometry
Same equipment
years an older can usually perform acceptable spirometry
Loops that meet criteria for good start of test and are free from artifact in the first second are considered .
If kid stops inhaling when flow is within % of PEF it is early termination and .

Spirometry ATS Standards
After tests:
Check that the 2 largest FVC are within . liters
Check that the 2 largest FEV1 are withink . liters
Save best 3 maneuvers