understanding spirometry spirometry interpretation workshop south/sat_room6_1100... · this is a...

Understanding Spirometry

Spirometry Interpretation Workshop

Saturday 13 August 2016

Presenters

Professor Lutz Beckert, Professor of Medicine, University of Otago, Christchurch Respiratory

Physician, Canterbury District Health Board, Christchurch

Dr Maureen P Swanney, Scientific Director, Respiratory Physiology Laboratory, Canterbury

District Health Board, Christchurch

Contributors to case presentations

Clinical Respiratory Physiologists: Laura Ploen, Emily Ingram and Verity Blakemore

Guideline for Spirometry Interpretation

1 Quanjer PH, Pretto JJ, Brazzale DJ, Boros PW. ‘Grading the severity of airways obstruction: new wine in new bottles’, Eur Respir J, 2014; 43: 505-512

2 ATS/ERS Task Force 2005, ‘Standardisation of lung function testing: Interpretative strategies for lung function testing’, Eur Respir J, 2005; 26: 948–968

Interpretation of Bronchodilator Response

An increase in FEV1 and/or FVC of 12% and 200 mL from the control (baseline value)

constitutes a positive bronchodilator response1.

Case 1A

A fifty-eight year old motor mechanic is coming to see you for an opinion about his shortness of breath

when changing car tires. He has smoked all his life and it has never caused any symptoms, however he

has significant exposure to exhaust fumes. He wonders if these may have damaged his lungs.

You request spirometry.

Interpretation

This is a technically accurate and repeatable spirometry test.

The FEV1/FVC ratio of 45% is well below the Lower Limit of Normal (LLN) of 66%. Based on an FEV1 z-

score of -4.09 these spirometry results indicate very severe airways obstruction.

Based on percent predicted FEV1 at 36%, the severity of the obstruction is severe.

Spirometry after the administration of a bronchodilator may inform the presence of any reversible

component.

Case 2A

Mike (55 years) had a recent admission to hospital following an episode of chest pain. Coronary

angiography had shown significant ischemic heart disease and he had four stents inserted 2 years ago;

the cardiologist commented his cardiac function is now ‘good as gold’. He is still short of breath and

comes to see you for an opinion as to whether he may need more stents.


Interpretation

This is a technically accurate pre- and post-bronchodilator spirometry test.

The FEV1/FVC ratio of 32% is well below the LLN of 66%. Based on an FEV1 z-score of -4.81 these

spirometry results indicate very severe airway obstruction.

Based on percent predicted FEV1 at 25% the severity of obstruction is classified as very severe.

Post-bronchodilator FEV1 shows a 1260 mL and 121% improvement, the FVC also improves by 1820mL

and 57%.

Case 3A

A 79 year old woman who has never smoked comes to see you for an opinion about her dyspnoea. After

the death of her husband she joined a local walking group but finds it hard to keep up with the rest of the

group. Her late husband used to smoke, she never did. She wonders why she is short of breath.


Interpretation

Spirometry is acceptable and repeatable.

The FEV1/FVC ratio of 51% is below the LLN of 63%. Based on an FEV1 z-score of -2.48 these spirometry

results indicate a moderate airway obstruction.

Based on percent predicted FEV1 at 54% the obstruction is classified as moderately severity.

Spirometry before and after a bronchodilator could be useful to investigate any reversibility of the

airways obstruction.

Case 4A

A 26 year old woman admits that she was rather nervous during spirometric testing. Her lung function

was requested by the anaesthetist as part of the work up for a lung biopsy. She took a photo of her lung

function report prior to her anaesthetic assessment and comes to ask you why her lung function is more

than 200% of the predicted value.

Below is her spirometry report.

Interpretation

The woman is clearly more than 122 cm tall which explains why she has such high %predicted values.

Therefore, before these results can be interpreted the correct height is required.

Case 5A

Roger (57 years) has just been released from prison. He is coming to see you because he is short of

breath walking up and down the local beach; he wonders if he has lost fitness during his time in prison.


Interpretation

End of test plateau not met - but after 21 seconds of exhalation this is unlikely to make a clinical

difference.

The FEV1/FVC ratio of 23% is well below the LLN of 66%. Based on an FEV1 Z-score of -4.70 these

spirometry results indicate very severe airway obstruction.

Based on percent predicted FEV1 at 25% the obstruction is classified as very severe.

Spirometry before and after the administration of a bronchodilator would be useful to identify any

reversibility of the airways obstruction.

Case 6A

Neil (49 years) is training for the Coast to Coast race and finds his fitness regimen is progressing very

slowly. He is coming to see you to have his lung function checked because he used to smoke during his

teenage years.


Only two repeatable spirometry results obtained. End of test plateau not achieved due to patient experiencing abdominal pain.

FVC may be underestimated. Flow variation was noted on best manoeuvre. Interpret with caution. All other spirometry test

criteria have been met.

Interpretation

Poor spirometry technique, the patient stopped after 5 seconds because of abdominal pain.

The FEV1/FVC ratio of 71% is above the LLN of 69%.

The FVC has a significantly reduced Z-score of -2.72 and falls below the LLN. This indicates a restriction

spirometric pattern which may be because of an early stop to the test.

The spirometry should be repeated when Neil is pain free. The shape of the expiratory curve suggests

airways obstruction. However, if the results still show a restrictive pattern this should be confirmed by

referral for lung volumes to measure his Total Lung Capacity.

Case 7A

Nathan (18 years) was born in New Zealand but grew up overseas and attended several international

schools, because his parents worked for the New Zealand embassy. He comes to see you with a year-long

productive cough, stomach pains and shortness of breath playing sports.


Interpretation


The FEV1/FVC ratio of 76% is within normal limits because it is above the LLN of 74%.

The FVC has a significantly reduced Z-score of -3.24 and falls below the LLN. This indicates a restriction

spirometric pattern.

This restrictive pattern should be confirmed by measuring the Total Lung Capacity.

Case 8A

This 84 year old woman gave up smoking when she retired almost 20 year ago. She is now becoming

short of breath on exertion, which is associated with some chest pain. You are concerned that she may

have developed COPD.


Interpretation


The FEV1/FVC ratio of 68% is within normal limits because this is above the LLN of 61% and the Z-score is -

1.00.

The FVC of 1.84 L is also above the LLN of 1.65 L and the Z-score of -1.21 is within normal limits. While the

percent predicted FVC is at 77% this does not represent a restrictive pattern.

This is normal spirometry, therefore a referral to cardiology is suggested to investigate angina.

Note: The FEV1/FVC ratio is below 70%, thus if the GOLD guidelines were used it would erroneously

suggest an obstructive pattern.

Case 9A

Alison is a fit 76 year old farmer who was rescued by helicopter from Fairlie with sudden onset of chest

pain. She had a pneumothorax, which responded well to treatment with a chest drain. After inflation a

chest X-ray showed her lung parenchyma wasn’t quite normal.


Interpretation

The FEV1/FVC ratio is 74% which is above the LLN of 63% and the Z-score is 0.00.

The FVC at 1.05 L is below the LLN of 2.00 L and has a Z-score of -3.75 indicating that spirometry is

showing a restrictive pattern. The reduction in FVC is also reflected by the low percent predicted value of

37%.

To confirm this spirometric restrictive pattern a referral for the measurement of Total Lung Capacity is

required.

Case 10A

It has become increasingly difficult for Faye (50 years) to climb stairs and she is currently under

investigation by a neurologist, however no diagnosis has been made as yet. Because she has a distant

smoking history you are concerned she may have developed COPD.


Spirometry was performed using a face-mask. Slow start to forced expiration, FEV1 may be overestimated.

All other spirometry criteria were met.

Interpretation

Spirometry was performed using a face-mask. Slow start to forced expiration, all other spirometry criteria

met. (FEV1 may be overestimated).

The FEV1/FVC ratio at 90% is within normal limits because it is above the LLN of 69%, and has a Z-score of

2.00.

The FVC at 2.50 L is significantly reduced below the LLN of 3.00 L, and the Z-score of -2.67 is reduced

suggesting a restrictive spirometric pattern. The predicted FVC is 65% of the predicted value.

This restrictive pattern should be confirmed by measuring the Total Lung capacity.

Case 11A

Brent is a 14 year-old school boy coming to see you because he is not quite keeping up when playing

school sports. He looks fit, however he says he can’t really run the distance of a rugby field.

You request spirometry before and after a bronchodilator.

Interpretation

End of test criteria not met therefore FVC may be underestimated.

The FEV1/FVC ratio of 43% is well below the LLN of 75%. Based on an FEV1 z-score -4.46 these spirometry

results indicate very severe airway obstruction.

Based on percent predicted FEV1 at 44% the obstruction is classified as severe.

Although the end of test criteria was not met the additional volume that may have been measured after

13.8 seconds is unlikely to change the spirometric pattern.

Post-bronchodilator FEV1 shows a 780 mL and 49% improvement, and the FVC also improves by 830 mL

and 23% indicating a significant bronchodilator response.

Case 12A

Verity is a successful accountant, who has never smoked. She has taken up running and is training for the

Christchurch Marathon. She comes to see you because she feels short of breath running and occasionally

hears wheezing noises. These ‘funny sounds’ are particularly pronounced in cold air or after speed

training. Her sister has been diagnosed with asthma.

You request spirometry before and after a bronchodilator.

Interpretation



The FVC is also normal because it is above the LLN and has a z-score of -0.60.

This is a normal spirometry test.

There was no significant improvement in the FEV1 or FVC after administration of the bronchodilator.

Case 13A

As part of a Hauora Maori initiative at Tuahiwi Marae, Ray managed to stop smoking after 30 years, lost

about 10 kg of weight, and is now training to walk the Buller Half-marathon. He comes to see you to be

checked out because despite his efforts he is still short of breath when walking.


Interpretation


The FEV1/FVC ratio of 44% is well below the LLN of 68%. Based on an FEV1 z-score of -3.83 these

spirometry results indicate severe airway obstruction.

Based on the FEV1 percent predicted of 45%, the results indicate severe airway obstruction.

Post-bronchodilator FEV1 shows a 670 mL and 43% improvement. No significant improvement has been

seen in the FVC.

Case 14A

Joseph came to see you because the inhalers the hospital prescribed are not working; he cannot recall the

names of the inhalers, but he remembers they are red, purple and blue.


Interpretation


The FEV1/FVC ratio of 35% is well below the LLN of 61%. Based on an FEV1 z-score -3.38 these spirometry

results indicate severe airway obstruction.

Based on the FEV1 percent predicted of 34%, these results indicate very severe airway obstruction.

Post-bronchodilator FEV1 shows a 320 mL and 37% improvement, the FVC also improves by 630 mL and

25%.

Case 15A

Nicola (22 years) comes to see you because her asthma medications are not working. She reports

frequent asthma attacks triggered by fights with her mother and cheap perfume, and often suffers from a

hoarse voice.

You request spirometry and flow – volume curves.

Interpretation

Spirometry was accurate and repeatable.

The FEV1/FVC ratio of 73% is just below the LLN of 76%. Based on a FEV1 z-score of -0.56, these results

indicate a mild obstruction.

Based on the FEV1 percent predicted of 93%, these results indicate mild obstruction.

A bronchodilator test would be helpful.

The FEF50/FIF50 ratio is 1.2 which is slightly above the expected normal ratio of <1.0. The shape of the

inspiratory flow volume curve also shows a truncated pattern. Upper airway obstruction should be

investigated.

Case 16A

Chris has been sent home from school because he became short of breath and wheezy during a football

game. His mother reports that he has longstanding asthma and that Chris often coughs during the night.


Interpretation

The FEV1/FVC ratio of 76% is borderline for the LLN of 75%. All z-scores are within normal limits.

The FVC is also above the LLN.

Post-bronchodilator FEV1 shows a 340 mL and 13% improvement, there was no significant improvement

in the FVC.

Case 17A

Teresa, a 26 year old woman is seeking some reassurance. Her mother is suffering from scleroderma and

while her lungs are becoming more scarred she is becoming increasingly short of breath. While Teresa

has no symptoms she is seeking reassurance that she has no early lung scarring.


Interpretation

These results are sub-optimal because of poor maximal inhalation prior to the forces expiration.

The FEV1/FVC ratio of 87% is above the LLN of 74%. The FVC is below the LLN and has a reduced z-score

of -2.35 suggesting a restrictive pattern.

This test should be repeated with stronger encouragement to inspire to TLC. If the restrictive pattern

remains apparent the TLC should be measured to establish the presence of restriction.

Case 18A

Tom is 16 years old and is considering joining the army after finishing the school year. He knows he needs to lose some weight, however he wants to know about his breathing because he used to have asthma. He doesn’t participate in sport very much because he is very unfit and stopped taking any inhalers a long time ago. You request a hypertonic saline challenge test.

Interpretation


Baseline spirometry FEV1/FVC ratio of 68% is below the LLN of 75%. Based on the FEV1 Z-score of -1.45

this indicates mild obstruction.

Based on the percent predicted FEV1 of 83%, these results indicate mild airways obstruction.

After 1.2 ml of nebulised 4.5% saline the FEV1 decreased by 15% which represents severe bronchial

hyper-responsiveness. A bronchodilator was administered after the challenge test and showed a

significant improvement in FEV1 from baseline spirometry.

Case 19A

Seventy five year old Grace is planning to do some extensive trekking during her holiday in Kathmandu.

She can’t recall as history of asthma, but sometimes takes her sister’s blue inhaler.


Interpretation

The quality of the test is acceptable.


The FVC at 2.38 L is just below the LLN of 2.39 L thus indicating a possible restrictive pattern.

Based on an FVC Z-score of -1.67 these spirometry results indicate a restrictive pattern which should be

confirmed by referral for lung volumes to measure his Total Lung Capacity.

STOP - This patient is female not male, so another report with the correct gender is required.

Interpretation


The FEV1/FVC ratio of 76% is above the LLN of 63%. The FVC at 2.38 L is above the LLN of 1.92 L, this

spirometry is normal.

All Z-scores are in the normal range.

Case 20A

Beverley has become increasingly short of breath as she has gained weight after menopause. She

occasionally notices night time wheezing and viral infections tend to cause a prolonged episode of cough

lasting for about three months at the time.


Interpretation


The FEV1/FVC ratio of 82% is above the LLN of 69%. The FVC is also within normal limits. All z-scores are

within normal limits.

Post-bronchodilator FEV1 shows a 300 mL and 12% improvement. There was no significant improvement

in the FVC. This is a borderline bronchodilator response.

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