Pulmonary Diagnostics �Lightning Round Pro-Con

Matthew O’Brien MS RRT RPFT FAARCJeffrey Haynes RRT RPFT FAARC

Learning Objectives

•  Understand the pros and cons of the following topics:–  IOS as an appropriate substitute for spirometry–  ABGs should be part of a “complete PFT”–  Spirometry and DLCO are all you really need–  Flow-volume loops are essential for diagnosis–  ATS/ERS spirometry guidelines must be strictly

followed–  A negative methacholine challenge rules out asthma

Learning Objectives

•  Understand the pros and cons of the following topics:–  Spirometry calibration is unnecessary –  Rapid gas analyzers are superior to bag-in-box

technology for DLCO–  DLCO should always be done post BD–  Airway resistance measurements aren’t necessary–  DLCO should always be adjusted with hemoglobin–  FENO is a useful tool to manage asthma

Our pro/con positionsImpulse oscillometry is an appropriate substitute for spirometry–  Pro: Matt–  Con: JeffABGs should be part of a “complete PFT”–  Pro: Jeff–  Con: MattSpirometry and DLCO are all you really need–  Pro: Matt–  Con: JeffFlow-volume loops are essential for diagnosis–  Pro: Matt–  Con: JeffATS/ERS spirometry guidelines must be strictly followed–  Pro: Jeff–  Con: MattA negative methacholine challenge rules out asthma–  Pro: Matt–  Con: Jeff

Our pro/con positionsSpirometry calibration is unnecessary–  Pro: Matt–  Con: JeffRapid gas analyzers are superior to bag-in-box technology for DLCO–  Pro: Matt–  Con: JeffDLCO should always be done post BD–  Pro: Jeff–  Con: MattAirway resistance measurements are not necessary–  Pro: Jeff–  Con: MattDLCO should always be adjusted with hemoglobin–  Pro: Matt–  Con: JeffFENO is a useful tool to manage asthma–  Pro: Matt–  Con: Jeff

Conflict of Interest

We have affiliations with, special interests, or have conducted business with the following companies that in context with this presentation might possibly constitute a real or perceived conflict of interest:

•  Morgan Scientific Inc. (Jeff)•  ERT (Matt)•  Medical Graphics Corporation (Matt)•  Methapharm (Matt)

Conflict of Interest

Any use of brand names is not in any way meant to be an endorsement of a specific product, but to merely illustrate a point of emphasis.

Impulse oscillometry is an �appropriate substitute for spirometry

Pro

Spirometry can be challenging for…

•  Some children

•  Some adults–  “If this tube were

smaller, I could blow faster”

–  “So you want me to blow and then take a deep breath in?”

“Appropriate substitute”

•  When effort, coordination or comprehension are suspect…what other effort independent tool do you have in your pulmonary toolbox?–  Airway resistance–  Auscultation–  Pulse ox

Oscillometric data

•  Look at the curve or plot of resistance.

•  Is it in the abnormal range?

•  Is the R5 % of

predicted > 150% of predicted?

Abnormalarea

PredictedplotforResistance

R5:160%

Oscillometric data

•  Look at the breathing pattern (blue line).

•  Is the impedance (Z) signal elevated during exhalation?

Inspira;on:Expira;on:

Oscillometry is an appropriate substitute for spirometry!

•  You can give a clinician something- when all you have is a poor quality spiro result.

•  We have a CPT code!–  94728

•  Oscillometric measures could replace FEV1 in bronchoprovocations?–  Exercise–  Methacholine

Impulse oscillometry is an �appropriate substitute for spirometry

Con

IOS is a cool idea, �but is it necessary?

•  Spirometry already…–  Dx Lung Disease–  Determines Severity–  Guides Therapy–  Assesses Rx Response–  Indicates Prognosis

In a standardized and validated fashion

Enright P. Chest 2015;148:1135.

IOS is better because� it’s easier to perform

Spirometry Quality Should Not �Be A Problem in Humans

•  Gochicoa-Rangel Pediatr Pulmonol. 2013;48:1231–  5-8 years BEV>88%, FET >87%, Repeatability >90%

•  Enright AJRCCM 2004;169:235–  20-90 years All ATS criteria: 90%

•  SA.R.A. AJRCCM 2000;161:1094–  65-100 years All ATS criteria: 77%

•  Borg Respir Care 2012;57:2032–  Adults All ATS/ERS: 92%

PFT Quality: Young vs. Old

22 month sample of spirometry quality (ATS/ERS)

80+ 40-50 p Spirometry 92.6% 91.5% 0.84 Haynes JM Respir Care 2014;59(1):16

Inadequate Reference Equations

•  Device-specific•  Limited subject pool•  Different for ages ranges•  Not multi-racial

Males Females

80-year-oldmales 80-year-oldfemales

GLI Demographics 72 centers, 33 countries

n = 74,187 healthy non-smokers

Age 3-95

57% female

Caucasians (57,395) -Europe, Israel, Australia, USA, Canada, Mexican Americans, South America, Algeria, Tunisia. African Americans (3,545) South East Asians (8,255) -Thailand, Taiwan, China south of the Huaihe River and Qinling Mountains North East Asians (4,992) -Korea, China north of the Huaihe River and Qinling Mountains

ABGs should be part of a “complete PFT”�

Pro

“Complete” Pulmonary Function Test

•  Lung Volumes•  Airflow•  Resistance/Conductance•  Muscle Strength•  Transfer Factor (DLCO)•  Gas Exchange

Why not just rely on DLCO?

Identical PaO2: 75 mm Hg

Isn’t SpO2 Just As Good?

Oops!

Oops!

ABG/Hemoximetry Data

•  Acid/Base: Is acidosis the cause of breathlessness?

•  Hypercapnia: Is NIV indicated?•  Hypoxemia: Cardiac shunt?•  Anemia•  Polycythemia•  Carboxyhemoglobinemia

ABGs Are Wicked PainfulPuncture Pain 0-100 mm

Giner 28Chest 1996

France 23Eur J Emerg Med 2008

Haynes 25Respir Care 2015

ABGs Are Wicked Painful

ABGs should be part of a “complete PFT”�

Con

“ABGs should not be part of a “Complete” PFT

•  First of all….What is a “Complete”?

•  Other names:–  Formal–  Long form–  Full battery–  Full set–  Full lung PFTs–  Full complete–  Full PFT panel

Saywhatyouwant:Spiro,LV,DLCO,BDsifindicated,Loop,RMF,LCI…SpO2,ABGonRA,6MWT….

Arterial Blood Gas during “PFT”

•  Very valuable… when indicated.

•  SpO2 is low.•  Patient appears cyanotic. •  Hypercarbia is

suspected.•  Hyperventilation needs

to be ruled out.•  No previous ABG data

with known pulmonary function compromise.

•  Pre lung transplant.•  Select pre-thoracic

surgeries.•  Chain smokers.

Unnecessary ABGs…•  Drives up the cost of

healthcare.

•  Exposes patients to:–  Possible pain–  Possible infection–  Possible nerve

damage–  Possible hematoma–  Possible pseudo-

aneurysm–  Co-insurance fees

~Cost of an Arterial Blood Gas•  Blood gas with

calculated saturation

•  Blood gas with measured oxygen saturation

•  Venipuncture•  Arterial puncture

•  CPT code: 82803

•  CPT code: 82805

•  CPT code: 36415•  CPT code: 36600

HbCOHbMetHb

$195

$278

$16

Spirometry and DLCO are all you really need �

Pro

PFTs: Two Purposes�1. “Physiologic Buckets” �

2. Quantify severity of abnormality

“Simplydescrip;ve”…Be\eruseistopredictoutcomes.

%PredictedcomparedtoReference,LLN,Zscore…

PerDr.MacIntyre….

Consider the value each diagnostic test provides. How will the info guide your

care?

•  Spirometry pre/post bronchodilator $200 /399 •  Flow volume loop $ 325

•  Lung volumes $ 350•  Diffusion capacity $ 400•  Arterial Blood Gas with puncture $ 270•  FENO $90•  MIPs / MEPs $225•  Methacholine Challenge

$996 $2781

250/550

350420

4462901252401150

2014 2018

Specific market strategies

•  Spirometry with post drug option

•  Diffusion capacity•  Multi breath nitrogen

washout–  Lung volumes–  Lung clearance index

(LCI)

Case study: Lung Cancer

Pre Post LL Lobectomy and Chemotherapy

Baseline Post LLL and Chemo

Was lung volume data that helpful??? DLCO is down 21%

44 Yr old Male: 68”, 350lbs, BMI 53

Complaint:Dyspnea…neversmoked

Diffusion results…44 yr old

LLNPredActual%Pred

Lung Volume results—44 yr old

LLNPredActual%Pred

Non-specificpa\ern…ERVlowbecauseofBMI…HowdoesthisinfohelpotherthanR/Orestric;on?Howdoesitaddvalue?

Spirometry and DLCO are all you really need

Con

Disease Patterns

SERIES ‘‘ATS/ERS TASK FORCE: STANDARDISATION OF LUNGFUNCTION TESTING’’Edited by V. Brusasco, R. Crapo and G. ViegiNumber 5 in this Series

Interpretative strategies for lungfunction testsR. Pellegrino, G. Viegi, V. Brusasco, R.O. Crapo, F. Burgos, R. Casaburi, A. Coates,C.P.M. van der Grinten, P. Gustafsson, J. Hankinson, R. Jensen, D.C. Johnson,N. MacIntyre, R. McKay, M.R. Miller, D. Navajas, O.F. Pedersen and J. Wanger

CONTENTSBackground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 948

Reference equations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 949

General issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 949

Spirometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 950

Lung volumes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 950

Diffusing capacity for carbon monoxide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 952

Types of ventilatory defects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 953

General issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 953

Obstructive abnormalities. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 953

Restrictive abnormalities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 955

Mixed abnormalities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 955

Comments on interpretation and patterns of dysfunction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 955

Severity classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 957

Bronchodilator response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 958

Central and upper airway obstruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 960

Interpretation of change in lung function. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 961

DL,CO interpretation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 962

Abbreviations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 963

KEYWORDS: Bronchodilator, diffusing capacity, lung volume measurements, spirometry,reference values, ventilatory defects

BACKGROUND

This section is written to provide guidance ininterpreting pulmonary function tests (PFTs) tomedical directors of hospital-based laboratoriesthat perform PFTs, and physicians who areresponsible for interpreting the results of PFTsmost commonly ordered for clinical purposes.Specifically, this section addresses the interpreta-tion of spirometry, bronchodilator response,carbon monoxide diffusing capacity (DL,CO) andlung volumes.

The sources of variation in lung function testingand technical aspects of spirometry, lung volumemeasurements and DL,CO measurement havebeen considered in other documents publishedin this series of Task Force reports [1–4] and inthe American Thoracic Society (ATS) interpret-ative strategies document [5].

An interpretation begins with a review andcomment on test quality. Tests that are less thanoptimal may still contain useful information, butinterpreters should identify the problems and the

AFFILIATIONS

For affiliations, please see

Acknowledgements section.

CORRESPONDENCE

V. Brusasco

Internal Medicine

University of Genoa

V.le Benedetto XV, 6

Genova I-16132

Italy

Fax: 39 0103537690

E-mail: vito.brusasco@unige.it

Received:

March 24 2005

Accepted:

April 05 2005

European Respiratory Journal

Print ISSN 0903-1936

Online ISSN 1399-3003

Previous articles in this series: No. 1: Miller MR, Crapo R, Hankinson J, et al. General considerations for lung function testing. Eur Respir J 2005; 26:

153–161. No. 2: Miller MR, Hankinson J, Brusasco V, et al. Standardisation of spirometry. Eur Respir J 2005; 26: 319–338. No. 3: Wanger J, Clausen JL, Coates

A, et al. Standardisation of the measurement of lung volumes. Eur Respir J 2005; 26: 511–522. No. 4: MacIntyre N, Crapo RO, Viegi G, et al. Standardisation of the

single-breath determination of carbon monoxide uptake in the lung. Eur Respir J 2005; 26: 720–735.

948 VOLUME 26 NUMBER 5 EUROPEAN RESPIRATORY JOURNAL

Eur Respir J 2005; 26: 948–968

DOI: 10.1183/09031936.05.00035205

Copyright!ERS Journals Ltd 2005

Obstructionin patients with concomitant reductions of FVC and FEV1 confirmation of obstruction requires the measurement of lung volumes

Measurement of absolute lung volumes may assist in the diagnosis of emphysema, bronchial asthma and chronic bronchitis. It may also be useful in assessing lung hyperinflation �

RestrictionTLC < 5th percentile of predicted�

A reduced VC does not prove a restrictive pulmonary defect

Mixed Defect

FEV1/VC and TLC < 5th percentile of predicted

�

SERIES ‘‘ATS/ERS TASK FORCE: STANDARDISATION OF LUNGFUNCTION TESTING’’Edited by V. Brusasco, R. Crapo and G. ViegiNumber 5 in this Series

Interpretative strategies for lungfunction testsR. Pellegrino, G. Viegi, V. Brusasco, R.O. Crapo, F. Burgos, R. Casaburi, A. Coates,C.P.M. van der Grinten, P. Gustafsson, J. Hankinson, R. Jensen, D.C. Johnson,N. MacIntyre, R. McKay, M.R. Miller, D. Navajas, O.F. Pedersen and J. Wanger

CONTENTSBackground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 948

Reference equations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 949

General issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 949

Spirometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 950

Lung volumes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 950

Diffusing capacity for carbon monoxide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 952

Types of ventilatory defects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 953

General issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 953

Obstructive abnormalities. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 953

Restrictive abnormalities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 955

Mixed abnormalities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 955

Comments on interpretation and patterns of dysfunction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 955

Severity classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 957

Bronchodilator response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 958

Central and upper airway obstruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 960

Interpretation of change in lung function. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 961

DL,CO interpretation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 962

Abbreviations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 963

KEYWORDS: Bronchodilator, diffusing capacity, lung volume measurements, spirometry,reference values, ventilatory defects

BACKGROUND

This section is written to provide guidance ininterpreting pulmonary function tests (PFTs) tomedical directors of hospital-based laboratoriesthat perform PFTs, and physicians who areresponsible for interpreting the results of PFTsmost commonly ordered for clinical purposes.Specifically, this section addresses the interpreta-tion of spirometry, bronchodilator response,carbon monoxide diffusing capacity (DL,CO) andlung volumes.

The sources of variation in lung function testingand technical aspects of spirometry, lung volumemeasurements and DL,CO measurement havebeen considered in other documents publishedin this series of Task Force reports [1–4] and inthe American Thoracic Society (ATS) interpret-ative strategies document [5].

An interpretation begins with a review andcomment on test quality. Tests that are less thanoptimal may still contain useful information, butinterpreters should identify the problems and the

AFFILIATIONS

For affiliations, please see

Acknowledgements section.

CORRESPONDENCE

V. Brusasco

Internal Medicine

University of Genoa

V.le Benedetto XV, 6

Genova I-16132

Italy

Fax: 39 0103537690

E-mail: vito.brusasco@unige.it

Received:

March 24 2005

Accepted:

April 05 2005

European Respiratory Journal

Print ISSN 0903-1936

Online ISSN 1399-3003

Previous articles in this series: No. 1: Miller MR, Crapo R, Hankinson J, et al. General considerations for lung function testing. Eur Respir J 2005; 26:

153–161. No. 2: Miller MR, Hankinson J, Brusasco V, et al. Standardisation of spirometry. Eur Respir J 2005; 26: 319–338. No. 3: Wanger J, Clausen JL, Coates

A, et al. Standardisation of the measurement of lung volumes. Eur Respir J 2005; 26: 511–522. No. 4: MacIntyre N, Crapo RO, Viegi G, et al. Standardisation of the

single-breath determination of carbon monoxide uptake in the lung. Eur Respir J 2005; 26: 720–735.

948 VOLUME 26 NUMBER 5 EUROPEAN RESPIRATORY JOURNAL

Eur Respir J 2005; 26: 948–968

DOI: 10.1183/09031936.05.00035205

Copyright!ERS Journals Ltd 2005

•  Mayo Clinic•  n= 4774•  Age >30 years•  Spirometry & LV via plethysmography

Lung Volumes in 4,774 Patients WithObstructive Lung Disease*Brian J. Dykstra, MD; Paul D. Scanlon, MD, FCCP; Monica M. Kester, MS;Ken C. Beck, PhD; and Paul L. Enright, MD

Study objectives: To determine the correlates of static lung volumes in patients with airwaysobstruction, and to determine if static lung volumes differ between asthma and COPD.Patients and methods: We examined the data from all of the adult patients (mean age of 69) whowere referred to a pulmonary function laboratory from January 1990 through July 1994 with anFEV1/FVC ratio of < 0.70 and tested using a body plethysmograph. Correlates were determinedusing regression analysis.Measurements and results: Of the 4,774 patients observed with evidence of airways obstruction,61% were men. Self-reported diagnoses included asthma, 19%; emphysema or COPD, 23%;chronic bronchitis, 1.5%; and !1-antiprotease deficiency, 0.6%. Fifty-six percent of the patientsdid not report a respiratory disease. The degree of hyperinflation, as determined by the residualvolume (RV)/total lung capacity (TLC) ratio, or the RV % predicted (but not the TLC %predicted), was strongly associated with the degree of airways obstruction (the FEV1 %predicted). Patients with moderate to severe airways obstruction and high RV and TLC levelswere more likely to have COPD than asthma. Of the 1,872 patients with a reduced vital capacitydetermined by spirometry testing, 87% had hyperinflation as defined by the RV/TLC, and 9.5%had a low TLC (with less severe airways obstruction).Conclusion: In patients found to have airways obstruction by spirometry, the additional measure-ment of static lung volumes added little to the clinical interpretation.

(CHEST 1999; 115:68–74)

Key words: asthma; COPD; hyperinflation; lung volumes

Abbreviations: AAP ! "1-antiprotease; ATS ! American Thoracic Society; FRC ! functional residual capacity;PF ! pulmonary function; RV ! residual volume; TGV ! thoracic gas volume; TLC ! total lung capacity; VC ! vitalcapacity

S tatic lung volume tests are often routinely or-dered along with spirometry for patients with

various chronic obstructive airway diseases. Twocommon reasons for ordering the lung volumes are(1) to determine the presence or degree of lunghyperinflation, and (2) to look for a superimposedrestrictive lung disorder. Static lung volumes includethe total lung capacity (TLC), the residual volume(RV), and the functional residual capacity (FRC).The definition of airways obstruction has been stan-dardized as an abnormally low FEV1/FVC ratio anda low FEV1 % predicted.1 However, the definition ofthe term “lung hyperinflation” is currently imprecise

and is variously based on posteroanterior and lateralchest radiograph patterns, the FRC % predicted, theRV/TLC ratio, the RV % predicted, or the TLC %predicted.

Thousands of static lung volume tests are per-formed in pulmonary function laboratories each yearin the United States, with estimated costs in therange of $75 to $200 per test. The American Tho-racic Society (ATS), the National Heart, Lung, andBlood Institute, and the European Respiratory Soci-ety formed a working group in 1992 to recommendstandards for the measurement and interpretation ofstatic lung volumes for pediatric and adult patients.2The working group noted that there was a paucity ofreported data regarding the correlates of static lungvolumes in patients with obstructive lung diseases,and that the diagnostic or predictive value of staticlung volumes in these common disorders was poorlydescribed.

The goal of this study was to determine thespirometric, anthropometric, and diagnostic corre-

*From the Rehoboth McKinley Clinic (Dr. Dykstra), Gallup,NM; the Mayo Clinic (Drs. Scanlon and Beck), Rochester, NY;and the University of Arizona (Ms. Kester and Dr. Enright),Tuscon, AZ.

Manuscript received February 24, 1998; revision accepted June9, 1998.Correspondence to: Paul Enright, MD, Respiratory SciencesCenter, 1501 N Campbell Blvd, Tucson, AZ 85724; e-mail:lungguy@aol.com

68 Clinical Investigations

Downloaded From: http://journal.publications.chestnet.org/ by Jeffrey Haynes on 11/10/2014

Lung Volumes in 4,774 Patients WithObstructive Lung Disease*Brian J. Dykstra, MD; Paul D. Scanlon, MD, FCCP; Monica M. Kester, MS;Ken C. Beck, PhD; and Paul L. Enright, MD

Study objectives: To determine the correlates of static lung volumes in patients with airwaysobstruction, and to determine if static lung volumes differ between asthma and COPD.Patients and methods: We examined the data from all of the adult patients (mean age of 69) whowere referred to a pulmonary function laboratory from January 1990 through July 1994 with anFEV1/FVC ratio of < 0.70 and tested using a body plethysmograph. Correlates were determinedusing regression analysis.Measurements and results: Of the 4,774 patients observed with evidence of airways obstruction,61% were men. Self-reported diagnoses included asthma, 19%; emphysema or COPD, 23%;chronic bronchitis, 1.5%; and !1-antiprotease deficiency, 0.6%. Fifty-six percent of the patientsdid not report a respiratory disease. The degree of hyperinflation, as determined by the residualvolume (RV)/total lung capacity (TLC) ratio, or the RV % predicted (but not the TLC %predicted), was strongly associated with the degree of airways obstruction (the FEV1 %predicted). Patients with moderate to severe airways obstruction and high RV and TLC levelswere more likely to have COPD than asthma. Of the 1,872 patients with a reduced vital capacitydetermined by spirometry testing, 87% had hyperinflation as defined by the RV/TLC, and 9.5%had a low TLC (with less severe airways obstruction).Conclusion: In patients found to have airways obstruction by spirometry, the additional measure-ment of static lung volumes added little to the clinical interpretation.

(CHEST 1999; 115:68–74)

Key words: asthma; COPD; hyperinflation; lung volumes

Abbreviations: AAP ! "1-antiprotease; ATS ! American Thoracic Society; FRC ! functional residual capacity;PF ! pulmonary function; RV ! residual volume; TGV ! thoracic gas volume; TLC ! total lung capacity; VC ! vitalcapacity

S tatic lung volume tests are often routinely or-dered along with spirometry for patients with

various chronic obstructive airway diseases. Twocommon reasons for ordering the lung volumes are(1) to determine the presence or degree of lunghyperinflation, and (2) to look for a superimposedrestrictive lung disorder. Static lung volumes includethe total lung capacity (TLC), the residual volume(RV), and the functional residual capacity (FRC).The definition of airways obstruction has been stan-dardized as an abnormally low FEV1/FVC ratio anda low FEV1 % predicted.1 However, the definition ofthe term “lung hyperinflation” is currently imprecise

and is variously based on posteroanterior and lateralchest radiograph patterns, the FRC % predicted, theRV/TLC ratio, the RV % predicted, or the TLC %predicted.

Thousands of static lung volume tests are per-formed in pulmonary function laboratories each yearin the United States, with estimated costs in therange of $75 to $200 per test. The American Tho-racic Society (ATS), the National Heart, Lung, andBlood Institute, and the European Respiratory Soci-ety formed a working group in 1992 to recommendstandards for the measurement and interpretation ofstatic lung volumes for pediatric and adult patients.2The working group noted that there was a paucity ofreported data regarding the correlates of static lungvolumes in patients with obstructive lung diseases,and that the diagnostic or predictive value of staticlung volumes in these common disorders was poorlydescribed.

The goal of this study was to determine thespirometric, anthropometric, and diagnostic corre-

*From the Rehoboth McKinley Clinic (Dr. Dykstra), Gallup,NM; the Mayo Clinic (Drs. Scanlon and Beck), Rochester, NY;and the University of Arizona (Ms. Kester and Dr. Enright),Tuscon, AZ.

Manuscript received February 24, 1998; revision accepted June9, 1998.Correspondence to: Paul Enright, MD, Respiratory SciencesCenter, 1501 N Campbell Blvd, Tucson, AZ 85724; e-mail:lungguy@aol.com

68 Clinical Investigations

Downloaded From: http://journal.publications.chestnet.org/ by Jeffrey Haynes on 11/10/2014

Lung volumes in patients with airflow obstruction�Dykstra et al Chest 1999;115:68

•  TLC % pred vs. FEV1% pred•  Correlation coefficient .33

airways obstruction. Asthma has also been associatedwith increases in lung volumes during acute bron-chospasm and during asymptomatic periods.12,13

Some of the increase in TLC noted during inducedbronchospasm was due to an artifact of measure-ment, because mouth pressure does not reflectalveolar pressure well during panting maneuvers inpatients with severe airways obstruction.14,15 Morerecent measurements of the TLC using chest radio-graph planimetry showed that the TLC does increaseslightly during bronchospasm.16 However, our re-sults do not support an association of TLC with thedegree of airways obstruction in adult patients withasthma.

A population study of 2,680 subjects in Italy foundthat the RV was inversely related to weight in healthyadult women.9 Our results confirm this finding inboth men and women with airways obstruction (seeTable 3). Perhaps reference equations for RV17

should include a correction for body weight. We alsofound that current smokers (when compared withex-smokers) had higher values of RV and TLC, aftercorrecting for other factors (see Tables 3, 4), al-though the Italian study9 found this association onlyin men.

A limitation of the present study is the use ofself-reporting when classifying lung disease patients.

Some patients may not remember correctly thediagnosis given to them by their physician. Somepatients undoubtedly had lung disease but had notbeen told so by their physician. Some patients weresent to the PF lab because of a history suggestinglung disease, and the results may have thenprompted their physician to apply a lung diseasediagnosis (which we did not obtain).

The predicted values of Miller and coworkers5,6

were used because both spirometry and static lungvolume reference values were available from thesame population sample. We did not use single- ormultiple-breath helium dilution techniques (or nitro-gen washout) to measure static lung volumes, be-cause these methods are known to seriously under-estimate lung volumes in patients with moderate tosevere airways obstruction when compared withbody plethysmography.18 Errors in the measurementof lung volumes using body plethysmography (with-out using an esophageal balloon to estimate alveolarpressure changes) are also known to occur in patientswith severe airways obstruction14, but these are verysmall when compared with measurements of theTLC from chest radiographs, especially if rapidpanting during airway occlusion is avoided,15,18 as inour study.

In summary, the measurement of static lung vol-

Figure 4. The association of the % of predicted total lung capacity (TLC % predicted) with the severityof airways obstruction (FEV1 % predicted) in patients with asthma only (open circles) and COPD only(solid squares). The two regression lines are significantly different below the 59% of predicted FEV1.

CHEST / 115 / 1 / JANUARY, 1999 73

Downloaded From: http://journal.publications.chestnet.org/ by Jeffrey Haynes on 11/10/2014

What is an acceptable rate of misclassification?

“Only 9.5% of patients with a low FVC and FEV1/FVC < .7 had a TLC < LLN”

In other words

Misclassified Lung Disease!

1/10

Goal: correctly classify 100% of patientsBeing right “most of the time” is not good enough

Flow-volume loops are essential for diagnosis �

Pro

Spirometry=Flow Volume Loop

•  Value–  Allows assessment of

inspiratory and expiratory flow mechanics

–  Helps you evaluate quality of FVC effort.

–  Helps assess response to therapy.

PulmonaryFunc;onTes;ngandCardiopulmonaryStressTes;ng,V.Madama,2ndedi;on,pg41

High value health care!!

•  You have the technology!

•  Value–  Helps assess possible

vocal cord dysfunction (VCD)

–  Helps identify fixed and variable flow abnormalities.

Case study: tracheal stenosis

67 yr., female, 67 inches, 240 lbs., trach stenosis, never smoked

Numeric data-- in contrast to the flow volume loop

Pre and post balloon dilation subglottic stenosis

Responsetotherapy!

Biphasic flow-volume loop in�granulomatosis with polyangiitis

h\p://dx.doi.org/10.1016/j.resinv.2016.01.002TheJapaneseRespiratorySociety.Elsevier

Pre-opera;ve Post-opera;ve

Flow volume loops…more bang for the buck

•  You are doing a spirometry test anyway…do the inspiration.

•  It is the right thing to do!

•  CPT code: 94375 (do not use/bill in conjunction with spiro, spiro pre/post, or airway resistance with impulse oscillometry)

Flow-volume loops are essential for diagnosis

Con

Is this Patient Normal?

Does this F/V loop change� your interpretation?

Is this patient obstructed?

Does this F/V loop change� your interpretation?

Is this patient restricted?

Does this F/V loop change� your interpretation?

Is there a BD response?

Do these F/V loops change� your interpretation?

Does this patient have large airway obstruction?

Does this patient have large airway obstruction?

F/V loops lack specificity

PoorEffort SubgloicStenosis

ATS/ERS spirometry guidelines �must be strictly followed

Pro

Spirometry Quality Standards

SERIES ‘‘ATS/ERS TASK FORCE: STANDARDISATION OF LUNGFUNCTION TESTING’’Edited by V. Brusasco, R. Crapo and G. ViegiNumber 2 in this Series

Standardisation of spirometryM.R. Miller, J. Hankinson, V. Brusasco, F. Burgos, R. Casaburi, A. Coates,R. Crapo, P. Enright, C.P.M. van der Grinten, P. Gustafsson, R. Jensen,D.C. Johnson, N. MacIntyre, R. McKay, D. Navajas, O.F. Pedersen, R. Pellegrino,G. Viegi and J. Wanger

CONTENTSBackground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320

FEV1 and FVC manoeuvre . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321

Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321

Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321

Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321

Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321

Validation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322

Quality control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322

Quality control for volume-measuring devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322

Quality control for flow-measuring devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323

Test procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323

Within-manoeuvre evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324

Start of test criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324

End of test criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324

Additional criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324

Summary of acceptable blow criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325

Between-manoeuvre evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325

Manoeuvre repeatability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325

Maximum number of manoeuvres . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326

Test result selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326

Other derived indices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326

FEVt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326

Standardisation of FEV1 for expired volume, FEV1/FVC and FEV1/VC . . . . . . . . . . . . . . . . . . . . 326

FEF25–75% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326

PEF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326

Maximal expiratory flow–volume loops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326

Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326

Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327

Test procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327

Within- and between-manoeuvre evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327

Flow–volume loop examples. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327

Reversibility testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327

Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327

Comment on dose and delivery method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328

Determination of reversibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328

VC and IC manoeuvre . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329

Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329

AFFILIATIONS

For affiliations, please see

Acknowledgements section

CORRESPONDENCE

V. Brusasco

Internal Medicine

University of Genoa

V.le Benedetto XV, 6

I-16132 Genova

Italy

Fax: 39 103537690

E-mail: vito.brusasco@unige.it

Received:

March 23 2005

Accepted after revision:

April 05 2005

European Respiratory Journal

Print ISSN 0903-1936

Online ISSN 1399-3003

Previous articles in this series: No. 1: Miller MR, Crapo R, Hankinson J, et al. General considerations for lung function testing. Eur Respir J 2005; 26:

153–161.

EUROPEAN RESPIRATORY JOURNAL VOLUME 26 NUMBER 2 319

Eur Respir J 2005; 26: 319–338

DOI: 10.1183/09031936.05.00034805

Copyright!ERS Journals Ltd 2005

c

A Valsalva manoeuvre (glottis closure) or hesitation during themanoeuvre that causes a cessation of airflow in a manner thatprecludes an accurate estimate of either FEV1 or FVC [3] willrender a test unacceptable.

There must be no leak at the mouth [3]. Patients withneuromuscular disease may require manual or other assistancefrom the technician to guarantee an adequate seal.

Obstruction of the mouthpiece, e.g. by the tongue being placedin front of the mouthpiece or by teeth in front of themouthpiece, or by distortion from biting, may affect theperformance of either the device or the subject.

Summary of acceptable blow criteriaThe acceptability criteria are a satisfactory start of test and asatisfactory EOT, i.e. a plateau in the volume–time curve. Inaddition, the technician should observe that the subjectunderstood the instructions and performed the manoeuvrewith a maximum inspiration, a good start, a smoothcontinuous exhalation and maximal effort. The followingconditions must also be met: 1) without an unsatisfactory startof expiration, characterised by excessive hesitation or falsestart extrapolated volume or EV .5% of FVC or 0.150 L,whichever is greater (fig. 2); 2) without coughing during thefirst second of the manoeuvre, thereby affecting the measuredFEV1 value, or any other cough that, in the technician’sjudgment, interferes with the measurement of accurate results[3]; 3) without early termination of expiration (see End of testcriteria section); 4) without a Valsalva manoeuvre (glottisclosure) or hesitation during the manoeuvre that causes acessation of airflow, which precludes accurate measurement ofFEV1 or FVC [3]; 5) without a leak [3]; 6) without an obstructedmouthpiece (e.g. obstruction due to the tongue being placed infront of the mouthpiece, or teeth in front of the mouthpiece, ormouthpiece deformation due to biting); and 7) withoutevidence of an extra breath being taken during the manoeuvre.

It should be noted that a usable curve must only meetconditions 1 and 2 above, while an acceptable curve must meetall of the above seven conditions.

It is desirable to use a computer-based system that providesfeedback to the technician when the above conditions are notmet. The reporting format should include qualifiers indicatingthe acceptability of each manoeuvre. However, failure to meetthese goals should not necessarily prevent reporting of results,since, for some subjects, this is their best performance. Recordsof such manoeuvres should be retained since they may containuseful information.

Between-manoeuvre evaluationUsing the previously described criteria, an adequate testrequires a minimum of three acceptable FVC manoeuvres.Acceptable repeatability is achieved when the differencebetween the largest and the next largest FVC is f0.150 Land the difference between the largest and next largest FEV1 isf0.150 L [21]. For those with an FVC of f1.0 L, both thesevalues are 0.100 L. If these criteria are not met in threemanoeuvres, additional trials should be attempted, up to, butusually no more than, eight manoeuvres. Large variabilityamong tests is often due to incomplete inhalations. Somepatients may require a brief rest period between manoeuvres.

Volume–time or flow–volume curves from at least the bestthree FVC manoeuvres must be retained. Table 5 gives asummary of the within- and between-manoeuvre evaluation.

Manoeuvre repeatabilityFor FVC measurements, acceptability must be determined byascertaining that the recommendations outlined previously onperforming the FVC test are met. The guidelines of the ATS [3]contain examples of unacceptable volume–time and corre-sponding flow–volume curves. Figure 3 shows a flow chartoutlining how the criteria for blow acceptability are appliedbefore those for repeatability.

The repeatability criteria are used to determine when morethan three acceptable FVC manoeuvres are needed; thesecriteria are not to be used to exclude results from reports or toexclude subjects from a study. Labelling results as beingderived from data that do not conform to the repeatabilitycriteria described previously is recommended. In addition, therepeatability criteria are minimum requirements. Many sub-jects are able to achieve FVC and FEV1 repeatability to within0.150 L. Manoeuvres with an unacceptable start of test or acough (unusable curve) must be discarded before applying therepeatability criteria and cannot be used in determining thebest values. Manoeuvres with early termination or a Valsalvamanoeuvre may be used for selecting the largest FVC andFEV1.

TABLE 5 Summary of within- and between-manoeuvreacceptability criteria

Within-manoeuvre criteria

Individual spirograms are ‘‘acceptable’’ if

They are free from artefacts [3]

Cough during the first second of exhalation

Glottis closure that influences the measurement

Early termination or cut-off

Effort that is not maximal throughout

Leak

Obstructed mouthpiece

They have good starts

Extrapolated volume ,5% of FVC or 0.15 L, whichever is greater

They show satisfactory exhalation

Duration of o6 s (3 s for children) or a plateau in the volume–time curve or

If the subject cannot or should not continue to exhale

Between-manoeuvre criteria

After three acceptable spirograms have been obtained, apply the following

tests

The two largest values of FVC must be within 0.150 L of each other

The two largest values of FEV1 must be within 0.150 L of each other

If both of these criteria are met, the test session may be concluded

If both of these criteria are not met, continue testing until

Both of the criteria are met with analysis of additional acceptable spirograms

or

A total of eight tests have been performed (optional) or

The patient/subject cannot or should not continue

Save, as a minimum, the three satisfactory manoeuvres

FVC: forced vital capacity; FEV1: forced expiratory volume in one second.

M.R. MILLER ET AL. STANDARDISATION OF SPIROMETRY

cEUROPEAN RESPIRATORY JOURNAL VOLUME 26 NUMBER 2 325

Cough/artifacts

Extrapolated Volume

EOT Criteria: FET ≥ 6 sec (3 sec pedi)

A Valsalva manoeuvre (glottis closure) or hesitation during themanoeuvre that causes a cessation of airflow in a manner thatprecludes an accurate estimate of either FEV1 or FVC [3] willrender a test unacceptable.

There must be no leak at the mouth [3]. Patients withneuromuscular disease may require manual or other assistancefrom the technician to guarantee an adequate seal.

Obstruction of the mouthpiece, e.g. by the tongue being placedin front of the mouthpiece or by teeth in front of themouthpiece, or by distortion from biting, may affect theperformance of either the device or the subject.

Summary of acceptable blow criteriaThe acceptability criteria are a satisfactory start of test and asatisfactory EOT, i.e. a plateau in the volume–time curve. Inaddition, the technician should observe that the subjectunderstood the instructions and performed the manoeuvrewith a maximum inspiration, a good start, a smoothcontinuous exhalation and maximal effort. The followingconditions must also be met: 1) without an unsatisfactory startof expiration, characterised by excessive hesitation or falsestart extrapolated volume or EV .5% of FVC or 0.150 L,whichever is greater (fig. 2); 2) without coughing during thefirst second of the manoeuvre, thereby affecting the measuredFEV1 value, or any other cough that, in the technician’sjudgment, interferes with the measurement of accurate results[3]; 3) without early termination of expiration (see End of testcriteria section); 4) without a Valsalva manoeuvre (glottisclosure) or hesitation during the manoeuvre that causes acessation of airflow, which precludes accurate measurement ofFEV1 or FVC [3]; 5) without a leak [3]; 6) without an obstructedmouthpiece (e.g. obstruction due to the tongue being placed infront of the mouthpiece, or teeth in front of the mouthpiece, ormouthpiece deformation due to biting); and 7) withoutevidence of an extra breath being taken during the manoeuvre.

It should be noted that a usable curve must only meetconditions 1 and 2 above, while an acceptable curve must meetall of the above seven conditions.

It is desirable to use a computer-based system that providesfeedback to the technician when the above conditions are notmet. The reporting format should include qualifiers indicatingthe acceptability of each manoeuvre. However, failure to meetthese goals should not necessarily prevent reporting of results,since, for some subjects, this is their best performance. Recordsof such manoeuvres should be retained since they may containuseful information.

Between-manoeuvre evaluationUsing the previously described criteria, an adequate testrequires a minimum of three acceptable FVC manoeuvres.Acceptable repeatability is achieved when the differencebetween the largest and the next largest FVC is f0.150 Land the difference between the largest and next largest FEV1 isf0.150 L [21]. For those with an FVC of f1.0 L, both thesevalues are 0.100 L. If these criteria are not met in threemanoeuvres, additional trials should be attempted, up to, butusually no more than, eight manoeuvres. Large variabilityamong tests is often due to incomplete inhalations. Somepatients may require a brief rest period between manoeuvres.

Volume–time or flow–volume curves from at least the bestthree FVC manoeuvres must be retained. Table 5 gives asummary of the within- and between-manoeuvre evaluation.

Manoeuvre repeatabilityFor FVC measurements, acceptability must be determined byascertaining that the recommendations outlined previously onperforming the FVC test are met. The guidelines of the ATS [3]contain examples of unacceptable volume–time and corre-sponding flow–volume curves. Figure 3 shows a flow chartoutlining how the criteria for blow acceptability are appliedbefore those for repeatability.

The repeatability criteria are used to determine when morethan three acceptable FVC manoeuvres are needed; thesecriteria are not to be used to exclude results from reports or toexclude subjects from a study. Labelling results as beingderived from data that do not conform to the repeatabilitycriteria described previously is recommended. In addition, therepeatability criteria are minimum requirements. Many sub-jects are able to achieve FVC and FEV1 repeatability to within0.150 L. Manoeuvres with an unacceptable start of test or acough (unusable curve) must be discarded before applying therepeatability criteria and cannot be used in determining thebest values. Manoeuvres with early termination or a Valsalvamanoeuvre may be used for selecting the largest FVC andFEV1.

TABLE 5 Summary of within- and between-manoeuvreacceptability criteria

Within-manoeuvre criteria

Individual spirograms are ‘‘acceptable’’ if

They are free from artefacts [3]

Cough during the first second of exhalation

Glottis closure that influences the measurement

Early termination or cut-off

Effort that is not maximal throughout

Leak

Obstructed mouthpiece

They have good starts

Extrapolated volume ,5% of FVC or 0.15 L, whichever is greater

They show satisfactory exhalation

Duration of o6 s (3 s for children) or a plateau in the volume–time curve or

If the subject cannot or should not continue to exhale

Between-manoeuvre criteria

After three acceptable spirograms have been obtained, apply the following

tests

The two largest values of FVC must be within 0.150 L of each other

The two largest values of FEV1 must be within 0.150 L of each other

If both of these criteria are met, the test session may be concluded

If both of these criteria are not met, continue testing until

Both of the criteria are met with analysis of additional acceptable spirograms

or

A total of eight tests have been performed (optional) or

The patient/subject cannot or should not continue

Save, as a minimum, the three satisfactory manoeuvres

FVC: forced vital capacity; FEV1: forced expiratory volume in one second.

M.R. MILLER ET AL. STANDARDISATION OF SPIROMETRY

cEUROPEAN RESPIRATORY JOURNAL VOLUME 26 NUMBER 2 325

Wisdom of George Banks

A British bank is run with precision. A PFT Lab requires nothing less! Tradition, discipline, and rules must be the tools! Without them: disorder, catastrophe! Anarchy! In short, you have a ghastly mess!

ATS/ERS spirometry guidelines �must be strictly followed

Con

ATS/ERS spirometry guidelines �must be strictly followed…

20pagehighqualitydocument

It’s great, but more of a guide….•  “According to ATS/

ERS…” •  Reference•  Standard•  Policy•  Rules•  Instructions•  Manual•  Recommendations•  Standardization

Standardization of spirometry is fantastic…and is the goal!

•  Hurtles–  Physicians / labs are

not always held to a high standard.

–  Training time is often minimal.

–  Staff in physician practices are often medical assistants or office staff.

–  Staff don’t have sufficient education to fully understand the ATS/ERS spirometry document.

20 pages or 3 pages ?

Proficiency is still needed

Is this an acceptable curve?

“ Just the facts ma’am”

A negative methacholine challenge� rules out asthma

Pro

A negative methacholine challenge� rules out asthma

•  “Methacholine challenge testing is more useful in excluding the diagnosis of asthma than in establishing one because its negative predictive power is greater than its positive predictive power.”

•  Pretest probability: wheezing, dyspnea, chest tightness, cough… –  With exposure to cold –  After exercise –  During respiratory infections –  Following inhalant exposures in workplace

ATSGuidelinesforMethacholineandExerciseChallengeTes;ng1999,AmJRespirCritCareMed2000161:309-329.

Coates Al, Wanger J, Cockcroft DW, et.al. ERS technical standard on bronchial challenge testing, general considerations and performance of methacholine challenge tests. Eur Respir J 2017; 49: 1601526 [https://doi.org/10.1183/13993003.01526-2016].

Clinical indications•  Assess airway responsiveness •  Spirometry before and after

bronchodilators has not helped establish a diagnosis.

•  Contribute to a dx of asthma •  Evaluation of occupational

asthma •  Evaluate risk of developing

asthma •  Assess severity of asthma •  Assess response to therapy

Must be true….

•  Military•  EMS•  Law enforcement•  Clearance for scuba

diving•  Offenders seeking “boot

camp” for early release•  Inmates, it evaluate if

medications are truly indicated.

•  Athletes•  Clinicians

Whousesthistest?

HisPD20isgreaterthan400ug,I

thinkheisgoodtogo!

•  “Bronchoprovocation with methacholine is a particularly sensitive diagnostic tool and can be used to exclude a diagnosis of asthma.”

A negative methacholine challenge� rules out asthma

Con

>99.999% sensitive & specific

Anderson SD. Respir Res 2009;10:4.

115 children with clinical asthma diagnosis

MCT PC20 16 mg/ml sensitivity 66.2

specificity 62.9

Methacholine and DI

Normal and mild AHR/asthma

Cockcroft, Davis. J Clin Allergy Immunol 2006;117:1244

•  50% with PC20 > 2 had negative test with dosimeter

•  25% of all subjects had a negative test with dosimeter

•  2 had a >120 mg increase in PC20

Spirometry calibration is unnecessary

Pro

How many syringes does your lab have?

The future is here! �“no calibration is required”!

It is because the manufacturing tolerances are nearly perfect!

Pneumotachs are tough!

•  Matt demo durability of pneumotach

Spirometry calibration is unnecessary

Con

Don’t be fooled!“You don’t need to calibrate this spirometer”

REALLY MEANS“You can’t calibrate this spirometer”

BUT YOU SHOULD ALWAYS VERIFY THE CALIBRATIONS IN THE DEVICE!!

The future is here! �“no calibration is required”!

Why do we need to verify calibrations?

Oh what a burden it is!

MGC Pitot Tube: ~50 seconds (10 strokes)

Morgan Screen: ~30 seconds (12 stroke)

Calibration, it’s not just �for breakfast anymore…..

Maybe this thing is more likely to fail during use than while

turned off for the overnight??

Change of Pitot Tube

Calibration repeated and failed

ErrorFVC: +1070 mlFEV1: +900 ml

Rapid gas analyzers are superior �to bag-in-box technology for DLCO�

Pro

Bag in box measurement equipment Gosh,Ihopethatlatexballoondoes

notbreak!Iwonderhow

theycleanthesethings?

Older diffusion systems: problems

•  Greater system dead space– More difficulty for folks with small VCs or

super obstructed. •  Slower analysis•  Do you have to clean the balloon?•  Parts to replace

– Balloons, solenoids

RGA analyzers: advantages

•  Measures gas sample right by the patient

•  Ability to obtain a measurement when VCs are smaller

•  Improved ability to accurately measure alveolar volume

RGA (rapid gas analyzer): Advantages

•  They are fast.0-90% response time of <150 ms.

•  Less system dead space to clear.•  Easy to replace sample line. •  Continuous measurement of gas sample.•  Less chance for leaks.

Sample line is close to the action

Common diffusion capable systems

Most modern PFT systems use a rapid gas analyzer.

Rapid gas analyzers are superior �to bag-in-box technology for DLCO�

Con

Bag in the Box Systems Do �Not Need a Demand Valve

•  Systems use gas vs. time instead of volume

•  Reference equations are based on bag in the box

•  There are no data that rapid gas analyzers are better

RGAs are Prone to User Error

CourtesyofBrianGrahamPhD

DLCO should always be done post BD

Pro

What is lung diffusion?•  Structural factors

–  Lung volume–  Thickness of AC

membrane–  Surface area of AC

membrane–  Capillary volume

•  Functional factors–  Ventilation –  Perfusion volume–  V/Q matching–  Alveolar gas

composition– Membrane diffusivity–  Hb volume–  Hb binding properties–  Capillary gas

pressures

DLCO post-BDPre BDDLCO 17.4 73%TLC 4.75VA 3.57TLC-VA 1.18Post BDDLCO 21.4 89% +23TLC 4.65VA 4.00TLC-VA .65

DLCO post-BD

VA 3.57 TLC-VA 1.18

VA 4.00 TLC-VA .65

DLCO should always be done post BD

Con

Workflow, workflow, workflow!•  Maybe…but….

–  This is the way we have always done it!

– My report is configured for the pre DLCO measurement.

–  I have to retrain my staff.

– What does that new DLCO technical standard say again?

The MD interpretation

–  I will only confuse my physicians.

–  What if the DLCO is improved?

–  What if I don’t have to give bronchodilators?

–  Next my docs will want DLCO pre and post BD…How do I get paid for that?

?

$

What about the effect of propellents on DLCO?

•  RGA analyzers can be confused by the propellent in the MDI?

•  So if I am doing neb treatments, I don’t have to worry about this?

DLCO should always be adjusted with hemoglobin

Pro

Anemia Correct for anemia if you have a current hemoglobin level.

37 yr. old, female, Leukemia

Reasons to adjust for Hb

•  You have a recent value (<2 weeks)

•  The patient is trying to qualify for BMT transplant

•  The clinical trial says you must.

•  The patient has a slightly low DLCO value.

Several equations exist!

•  Methods – Hb correction according to ATS (Cotes)

•  13.4 g/dL females and 14.6 g/dL males •  TLCOc=actual value/1.7*Hb/(10.22+Hb) males

/1.7* Hb/(9.38+Hb) Females

– Hb correction according to Hilpert •  13.5 g/dL females and 14.6 g/dL males •  TLCOc=actual value/0.0646*Hb + 0.0568 males

/0.0646*Hb + 0.1279 females

– Hb correction according to Dinakara equation Ref: CIBMTR (Center for international bone and marrow transplant research)

•  DLCO corrected=uncorrected DLCO 0.06965*Hb

Case study: Hb correction •  68 yr old female, SOB, dyspnea on exertion, 68”, 187 lbs, BMI 29

Case study: DLCO Hb correction •  Physician order:

–  Please perform CPX on a bike with arterial line and ABG sampling at pre-test, and every 3 minutes after start of exercise and post test.

–  12 Lead ECG –  Approximate cost of

$2600 + arterial line and interpretation.

Pre exercise ABG

Case study: Hb correction

DLCO should always be adjusted with hemoglobin

Con

What is the Impact of Hemoglobin & COHb Adjustment?

Haynes, Ruppel, Kaminsky Chest 2017;151(5):1188

FENO is a useful tool to manage asthma

Pro

Asthma is often an enigma•  A person or thing that is mysterious, puzzling, or difficult to understand.

•  Multiple asthma phenotypes

Biomarker use?

Niox Vero•  Portable FENO

measurement–  FDA approved

•  Ecomedics–  Not FDA

approved

We need a variety of tools•  Spirometry•  Flow volume loops•  Bronchodilators•  Lung volumes•  Methacholine challenge•  Exercise challenge•  Eucapnic challenge•  Mannitol•  Hyperpolarized MRI

imaging•  FENO

•  $250•  $350•  $500•  $400•  $1100•  $1000•  $1000•  $ unk•  $ crazy expensive

•  $ 125

FENO…do you need a sixth sense to uses it?

•  Cough• Dyspnea•  Possible asthma

CHEST 2008•  Convenient•  Non-invasive•  Point of care•  Office test•  Helpful in the dx of

asthma•  Assessment of

adherence of medication

•  Trending•  Screening

Recent guidance

2017

Recent guidance

2017

How do you find airway inflammation? � Hit or miss or use a tool?

FENO is a useful tool to manage asthma

Con

Hospitalizations no differenceSystemic steroids no differenceICS dose no differenceFEV1 no differenceFENO no differenceSymptom scores no difference

Exacerbation rates no differenceICS dose no differenceFEV1 no differenceFENO no differenceSymptom scores no difference

Audience Participation