Asthma Spirometry

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AsthmaSpirometry Devices

• BUMED Asthma Action Team

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Objectives

• To understand the basic mechanics of respiration
• To have a basic understanding of how to properly
  administer spirometry to pediatric asthma
  patients.
• To understand the value of spirometry in the
  asthma clinic setting
• To provide patient education relating to testing
  and treatment

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Dynamics of Breathing

• Inspiration Negative intrathoracic pressure
  relative to atmosphere. Diaphragm and
  inspiratory muscles contract, lungs fill
  passively.
• Expiration Passive process resulting from
  elastic recoil of expanded lung walls. During
  rapid breathing, internal intercostal and
  abdominal muscles contract to force air out of
  lungs.

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Spirometry

• The measurement of the flow and volume of air
  entering and leaving the lungs.

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Pulmonary Function Testing

• Dependent upon
• Age
• Body Size (height and weight)
• Gender
• Pulmonary Health
• Altitude
• Irritants
• Effort dependant, (patient tech)

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Dynamic Lung Volumes

• Valuable in spirometry for following the progress
  of a patient with asthma
• Can be used to assess response to treatment
  (pre/post bronchodilator)
• Help assess lung health
• Does not provide the diagnosis, but can
  demonstrate if lung function is consistent with a
  diagnosis

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Dynamic Lung Volumes

• Forced Vital Capacity (FVC) Volume expired by a
  forced maximal expiration after maximal
  inhalation, also known as FEV6.
• Forced Exp. Volume in 1 second (FEV1) Volume of
  air forcefully expired in the first 1 second from
  a position of maximal inspiration.

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• FVC
• The largest volume of air
• that can be forcefully
• expired from
• the lungs

exp

insp
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• FEV1
• The largest
• volume of air that can be forcefully
• expired in the first second
• Indication of long-term risk in asthma

exp

1sec
insp
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• FEV1/FVC
• The ratio of FEV1
• to FVC expressed as
• a percentage. It is
• the most commonly
• used measurement
• of airway obstruction.
• Provides severity classification level of
  asthma control.

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• FEFmax (PEFR)
• The maximal
• expiratory flow
• generated during
• a forced maneuver.
• Referred to as the
• effort or the blast.

FEF Max

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Administering PFTs in Children

• Requires pt cooperation (unlikely in children
  less than 5-6 yrs).
• Requires a technician who is sensitive to the
  needs of children.
• Practice makes perfect!
• Calm, success-oriented
• environment.

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Administering PFTs in Children

• Ask child to take a full breath (to maximal
  inflation), followed by a brief hold.
• Next, perform a maximal forced exhalation for at
  least 3 seconds.
• Blow out all your birthday
• candles.

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Standards for the Testing Environment

• Torso and head should be erect in sitting or
  standing posture
• Nose clip should be used
• Special training is required for test
  administrators

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Standards for the Testing Environment

• All reports should include date of birth, date of
  test, weight/height, sex, race, absolute values
  of all measurements with percent of predicted
  values and conditions of test
• VC should be reported as the largest value
  obtained from any of the respiratory maneuvers
• Best of three
• Best test is the one with the greatest sum of
  FEV1 and FVC

Data from Taussig LM, Chernick V, Wood R, et al
Standardization of lung function testing in
children. J Pediatr 97 668-676, 1980
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Performing the Test

• Obtain height and weight by physically taking the
  patient to the scales to measure height weight
• Explain and demonstrate the testing maneuver to
  the patient and parents, practice, and get the
  child to feel comfortable with procedure
• Perform testing, 3 consistent tests with
  repeatable results
• Administer bronchodilator if indicated, retest

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Coaching during testing

• Perhaps the MOST important aspect of testing.
• Deep breath in, BLAST it out, keep blowing,
  blowing, blowing, DEEP breath in, and that's
  done!
• Techs should become competent by TAD training,
  civilian PFT labs, extend out a Medivac to
  include time in the PFT lab of a major MTF, or
  manufacturer inservice.

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• ATS (American Thoracic Society) criteria
• Acceptability and reproducibility criteria
  include

• Expiration minimum of 6 seconds or until no
  volume change for at least 1 sec
• Three acceptable efforts should be saved for
  interpretive purposes
• The two largest FVC and FEV1values should agree
  within 150ml

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• ATS (American Thoracic Society) criteria
• Acceptability and reproducibility criteria
  include

• No hesitation at the start of the test
• Back extrapolation should be less than 5 of the
  FVC or 150cc
• Absence of coughing during test
• No glottic closure, mouthpiece obstruction by
  tongue, and/or leaks

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• ATS (American Thoracic Society) criteria

Testing should continue until - Three
acceptable tests have been achieved, -
Patient just cant perform testing,
and/or - The patient just cannot continue.
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The technicians job is to also be able to
recognize poor efforts

• glottic closure
• poor expiratory
• flows
• inconsistencies in
• volumes flows
• coughing

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Interpreting Results

• Spirometry allows comparison of patients lung
  function to reference values.
• Technicians should refrain from diagnosing any
  test directly to the patient.
• Should be interpreted by a pediatric asthma
  specialist until competencies are demonstrated
  for certification.

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Example of Glottic Closure
Glottic closure
Normal
Flow ceased (red) Continuous flow (white)
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Poor Expiratory Efforts, inconsistencies, and
coughing examples
Hesitation, causing back extrapolationloss of
volume in first 10 of flow
No effort heredid not blast
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Poor Expiratory Efforts, inconsistencies, and
coughing examples
Stopped flow prematurely Glottic closure
By placing the flow loops on top of each other,
you can see the inconsistencies
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Interpreting Results

• Flow-volume loop highest point of curve is the
  peak flow rate
• Volume expired versus time helpful in
  determining FEV1

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Interpreting Results

• Numerical data Patient values compared to
  predicted values for dynamic lung volumes

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Interpreting Results

• Assess quality of study!
• Appropriate curve shape without artifact.
• Sustained expiration for 3 seconds.
• At least 3 FVCs within 150ccs of best effort
  (except in very young).
• Satisfactory effort as determined by tester.
• Response to bronchodilator gt12 increase in FEV1

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Pattern Recognition
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Recognizing Artifact
Poor Effort
Coughing
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Recognizing Artifact
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Quality Assurance for Interpretations

• Studies should be entered into AHLTA
• Results should be made available to Dr. Wojtczak
  or Dr. Lee for review pending asthma treatment
  certification

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Literature for testing

• Outcomes Associated With Spirometry for Pediatric
  Asthma in a Managed Care Organization, Pediatrics
  2006118151-156
• Forced Expiratory Volume in 1 Second Percentage
  Improves the Classification of Severity Among
  Children With Asthma, Pediatrics
  2006118347-355
• Office Spirometry in Primary Care Pediatrics,
  Pediatrics 2005 116792-797
• Guidelines for the Diagnosis and Management of
  Asthma, NIH, Nov 1997

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Spirometry in Asthma Care

• Should be a tool for diagnosis and treatment.
• Can be used to help determine appropriate
  medications

1. Office spirometry in primary care pediatrics
a pilot study. Pediatrics. 2005
Dec116(6)e792-7 2. The influence of pulmonary
function testing on the management of asthma in
children. J Pediatr. 2005 Dec147(6)797-801. 3.
Evaluating the use of a portable spirometers in a
study of pediatric asthma. Chest. 2003
Jun123(6)1899-907.
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Summary

• Spirometry is an important diagnostic tool which
  should be used in the primary care setting.
• Requires proper training for physicians, nurses,
  techs.
• Portable spirometry equipment produces quality
  studies and allows for testing in clinical
  setting.

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Asthma Treatment Tools
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Spirometers

• Ferraris KoKo Spirometer
• PC based, easy to use, ability to network, and a
  pediatric display.

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Spirometers

• Creative Biomedics DX-Portable Plus
• Self-contained portable unit, pediatric display

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Spirometers

• SDI Diagnostics, Spirolab II
• Small self-contained unit, no pediatric display,
  cant network
• into AHLTA

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Treatment Inhaler use

• Shake Medication
• Exhale
• Inhale medication slowly
• Hold your breath 10 seconds
• Slowly Exhale

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Treatment . . . Is my Inhaler empty?

• Keep track of your puffs
• Controller inhalers have between 60-120 puffs
• Rescue inhalers have 200 puffs
• Replace when EMPTY
• Rinse mouth after using steroids!

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Home Nebulizers

• Most MTFs have units for home use.
• Open unit, attach nebulizer, add medication, turn
  on, and breath till meds are done.

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Treatment . . . Valved Holding
Chamber

• Insert the inhaler into the back piece of the
  chamber
• Shake, exhale, squirt, inhale slowly, hold 10
  seconds and then exhale slowly
• Clean your spacer initially and weekly, warm
  soapy water, rinse well, air dry only.

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Aerochamber with mask

• If using a mask, spend time getting the child
  used to it, seal it well over face, watch for
  flapper valve movement, administer meds, hold on
  face for 15 seconds.

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Monitoring Asthma

• Peak flow meter
• A simple test that can be completed at home or
  school
• Follow package directions to determine zones
• Deep breath in, blast out
• Best of 3 efforts
• Record results