A. TLC < 80% predicted and all other volumes reduced proportionally = restriction
A. RV, FRC, and RV/FRC increased = air trapping
B. If airtrapping continues and grows, retrosternal air develops and you move into hyperinflation
C. TLC > 95% predicted = probable hyperinflation
Diffusion (DLCO) results should be examined with spirometry and lung volumes in mind
DLCO/VA used for interpretation (alveolar volume) A. DLCO/VA low + obstruction (airtrapping, hyperinflation?) =
emphysema
B. DLCO/VA low + restriction (all volumes reduced) = fibrosis C. DLCO/VA normal + obstruction (airtrapping, hyperinflation?) =
bronchitis
D. DLCO/VA low + no lung obstruction or restriction = low hemoglobin , decreased blood flow (PE)
No bronchodilators, antihistamines, coffee, tea, chocolate (methylxanthines and
theobromines)
Do a complete PFT - must be free of air flow obstruction (AFO)
Bland aerosol to start to check for reaction F/V loop at 30 seconds and 90 seconds .
Low dose of *methacholine (provacholine) inhaled.
Progressively increase if negative. Start at
0.025mg/ml, 0.25 mg, 2.5mg , 10mg, up to 25mg. Positive response is a 20% decrease in FEV1
Finish with a bronchodilator - FEV1 must be within 5% of baseline to go home
*Histamine has also been used in other countries
The absence of airways obstruction does not rule out asthma.
(Normal spirometry?)
A negative response to bronchial provocation does.
A positive response is not totally clear but adds to the pieces that say “asthma” (COPD, sinusitis may be positive)
OR – if you have asthma, you have “twitchy” airways that will react to provocation. No response? no
asthma.
Spirometry – 6 standards
◦ Minimum 3 spirograms recorded
◦ 2 of the 3 have + 150 ml in FVC and FEV1, +10% in
◦ PEF Start of test is acceptable (BEV < 5% of FVC)
◦ 6 second exhalation
◦ End of test criteria met (plateau)
MVV – 2 standards
◦ 1 breath/second or total rate 60 to 75 breaths/minute
◦ Goal = FEV1 x 40 (or 35 based on textbook)
Lung Subdivisions
◦ Gas analysis… machine is in good calibration, no leaks
◦ Gas reaches acceptable level
N2 - stop after 7 minutes if not at ~ 1%
He % is constant (plateau at + 0.02% for 30 seconds)
Plethysmography
◦ Shutter closes to measure VTG at FRC level
◦ Panting at about 60/min (1 Hz)
◦ Two recordings have to be within +10% in all measured values to be acceptable
DLCO
◦ Inspired volume is > 90% of best FVC
◦ Breath hold time 9 – 11 seconds, no leaks
◦ Discard first 750 ml before analyzing
◦ Tracer gas and CO calibration is good
◦ Two tests needed that are within + 10 % or 3 ml CO (using the raw DLCO number)
Review the demographics
◦ Age, height, gender, race, weight
Check the symptoms
◦ Cough (dry?), SOB, wheezing, chest tightness
◦ Any patterns? Seasonal, occupational?
When was the last time they had a SABA? LABA?
ICS?
Look over the history and chief complaint
◦ Smoker? Pack yrs? Include pipe, cigar, waterpipe
◦ Comorbidities?
Ischemic heart disease (CAD), hypertension, CHF, pulmonary hypertension, M.I., stroke
Lung cancer
Restrictive lung diseases (asbestosis, sarcoidosis)
Pulmonary embolism
Pneumonia, CF, bronchiectasis
DM, obesity, OSA, malnutrition, GERD
Dementia, Alzheimers, depression
Neuromuscular diseases
Osteoporosis, arthritis, gout, hearing loss, vision loss
Read the comments made by the person coaching the test
“C/O chest pain”
“Frequent coughing”
“Unable to perform test, unable to follow instructions”
Look at the graphs
Study the numbers and check against the predicted values
<80 % predicted or <LLN to define abnormalities
History
The patient is a 73-year-old black woman with a previous
history of COPD. She denies cough or sputum production. She states that any activity results in breathlessness. She has a 50 pack-year smoking history but quit 4 years ago.
She had repeated bouts of pneumonia as a child, but has no other occupational or exposure history. She currently takes Advair and uses albuterol as a rescue inhaler. She has not used either medication this morning
66.5 inches tall, 230 lbs
African-American
Hb 12.21 g/dl
Spirometry Predicted Measured
Pre-tx % Predicted Measured
Post -tx % Predicted % Change
Diffusion Pred Actual %Pred DLCO(ml/min/mm HG)
18.1 8.8 49
DLCOcor (ml/min/mm
HG) 18.1 9.3 51
DL/VA
4.31 2.79 55
VA (L)
4.38 3.32 76
Hb 12.21 g/dl
Good example of a common pattern of pulmonary pathology associated with COPD.
PFT shows severe airway obstruction seen in the FEV1 and FEV1ratio.
MVV – patient reached her goal (FEV1 x 40)
Lung volumes show air trapping (increased RV and RV/TLC ratio) and hyperinflation
(increased TLC). The slow VC is significantly larger than even the post-bronchodilator
FVC.
These findings are suggestive of emphysema
Patient’s response to inhaled bronchodilator suggests some reversibility of the
obstruction (Asthma too?).
Her DLCO shows a severe reduction in diffusion
(DLCO/VA) suggestive of emphysema (e.g., loss of alveolar surface area, destruction of capillaries, and increased diffusion distance from the terminal
airways).
40 yr old white male c/o SOB with activities.
Has had problems from childhood with wheeze, SOB
Also snores and makes loud noises during sleep
Has been taking DPI flucticasone/salmeterol (250/50) 1 puff BID and albuterol MDI 2 puffs PRN- did not feel that they did much
Had a sleep study that was read as negative but patient stated that he “couldn’t sleep”.
Being treated for asthma. We saw him at the Victory clinic on his 5th visit
PMH includes obesity, renal stones, deviated septum, HTN (controlled) He is 6’3” tall and 320 lbs.
Only hospitalization was in 2000 for a catfish puncture to his hand.
Family history: Son has asthma, Mother – DM, renal stones. Father has hyperlipidemia
Occcupation: Commercial fisherman
Married , never smoked, drinks about 3 beers a month and about 3 glasses of tea or coffee a day.
1st visit in July with c/o bilateral swelling in
his legs, 30 lb weight gain in 3 months. Some DOE noted. Had some labs drawn
2nd visit - August F/U with lab work, c/o lumbar pain – Tx with moist heat and
stretching
3rd visit Oct. c/o dry cough, sinusitis. More issues with DOE, SOB
4th visit 2 weeks later in Oct. – nothing remarkable noted
Referred to Pulmonary clinic in Nov. for his 5th visit. Spirometry done with frequent
errors, hard to get a good quality recording.
Odd phonation noted.
FVC- 4.89 L (79% predicted) FEV1- 3.74 L (76% predicted FEV1/FVC – 76%
No time to get pre/post… we had class
Rescheduled for further testing
51 yr old female -chief complaint: SOB and cough
Arrived to the ED with cough, chest congestion, fever, chills. Prod cough- thick yellow sputum
PMH includes CHF,COPD, HTN, ASCVD with stents placed in 2007
Current medications include carvedilol (Coreg), Albuterol MDI 2 puffs BID, lovenox (Enoxaparin), HCTZ, lisinopril (Zestril)
No known allergies
Social history: Divorced, 2 PPD for 30 yrs (60 pk/yr)
Family history includes Cancer, COPD
Vitals: BP 145/92 mm Hg, HR 128 beats/min, Resp.
24 breaths/min, Temp 97.8 F. SpO2 on Room air- 88%
Physical exam
◦ General – pleasant 51 year old female, awake and alert, mildly dyspneic, occaissional congested cough
◦ HEENT: Not remarkable
◦ Neck: trachea midline without JVD
◦ Chest: Bilat BS equal with scattered wheezing and basilar crackles
◦ Heart: Regular S1 and S2. No gallops or murmurs
◦ Abdomen: Soft, nontender, nondistened
◦ Extremities: no cyanosis, some mild clubbing, no edema
◦ Ht 5’3”, Wt 113 lbs
CBC:
◦ WBC 14.2 (H) 3.8 – 11.0 k/uL
◦ RBC 4.36 3.8 – 5.1 m/uL
◦ Hemoglobin 10.1 (L) 11.0 – 16.0 g/dL
◦ Hematocrit 33.2 34-47%
Metabolic panel: Meas. Normal range Units
◦ Sodium 131 (L) 135 – 148 mmol/L
Sorry - Post
SABA results are missing
Spirometry shows Mrs. Jones has very severe COPD by GOLD guidelines
Her only pulmonary medication on admission was albuterol MDI, 2 puffs BID
GOLD recommends vaccinations, SABA, LABA (one or more), pulmonary rehabilitation, ICS if repeated exacerbations (at medium dose),
oxygen therapy if in chronic respiratory failure, and consideration for LVRS
Diagnosis: Stage IV - Very Severe COPD
◦ Oxygen at 2 L/min. Keep SpO2 > 90%
◦ Albuterol, 2 mg Q4 w/a and PRN a night
◦ Symbicort, 160/4.5 mcg 2 puffs BID (rinse after)
◦ Ceftriaxone (Rocephin), 2 g IV daily
◦ Prednisone, 80 mg daily for 7 days
◦ Nicotine replacement patch, 21 mg/day
◦ Bupropion, 150 mg once daily
Smoking cessation counseling
Nutritional consult
Social services to discuss end-of-life issues, patient assistance program for medications
At discharge: Set-up home oxygen, nebulizer, start pulmonary rehabilitation
Consider metered dose inhaler for LABA, ICS combination (Symbicort, Advair MDI,
Dulera)… her inspiratory flow is likely too low to administer a DPI (cannot access Spiriva,
Advair diskus)
Technologist must be well-trained and should have quality checks performed periodically for competency
Quality should include calibration checks daily?
Abnormal spirometry showing obstruction
should have pre/post SABA assessment made
Abnormal spirometry often calls for more testing to evaluate lung volumes and
diffusion
Spirometry provides best diagnostic evidence, clear, objective measurement, basis for tracking changes, guides best practice for treatment
Spirometry results should not exist in a vacuum – history, symptoms, demographics, current
medications, co-morbidities, technologist
comments on the test, etc. must be included.
To get a correct interpretation and to decide on treatment – other PFT tests may be needed (in addition to lab, radiologic tests)