Ms Priya PattniClinical Physiologist

WDHB

Hamilton

11:00 - 11:30 How to Improve Lung Function Testing

How To Improve Lung function Testing

By Priya L Pattni

Clinical Physiologist CRFS

Key Points

• Spirometry testing

• Indication and contra-indication in brief

• Requirements for the test

• Understand what it measures

• Acceptability and repeatability in detail

• Some common dialogues to improve coaching spirometry

Spirometers

• Portable with minimum moving parts

• Turbine spirometers

• Directly measure flow

• Directly measure volume

Indications

• Screening• Chest pain with no cardiac explanation

• Shortness of breath (COPD early pathology is inflammation and is asymptomatic until FEV1< 50% predicted)

• Cough (chronic or acute) (productive or not)

• Hyperinflation• Respiratory wheeze, stridor or chest tightness

• Scoliosis

• Reduced breath sounds

• Cyanosis• Monitoring

Contra-indications

• Hemoptysis

• Pneumothorax

• Unstable cardiovascular state (recent MI or pulmonary embolism).

• Aneurysm - abdominal, thoracic or cerebral.

• Recent eye surgery

• Uncontrolled hypertension

• Incontinence

• Dementia

• Acute process e.g. nausea & vomiting• Patient not willing

Complications?

• Increased intra-cranial pressure

• Dizziness

• Chest pain only minor stitch pain due to exertion, unless any unstable cardiac condition present

• Paroxysmal coughing

• Hypoxemia

• Bronchospasm

Patient Preparation

∙ No xanthine or caffeine ( tea, coffee, coke)∙ Resting for 15 minutes∙ Make note of all medications patient is taking∙ Note of patient’s smoking history ∙ Ask about any recent illness or medical procedures done∙ Ensure that patient’s clothes are loose

∙ Take standing height and weight without shoes

please note: tests may also be done on inhalers, depending on the clinical question asked

Airway network

Lung volumes

Volume-Time Graph

Components of FV-Loop

• FV-Loop labelled with components

Components of FV-Loop

• FEV1: Forced expiratory volume in first second, is the volume of air exhaled forcefully in first second after maximal inhalation

• FVC: Forced Vital capacity, is the total volume of air exhaled forcefully until no more air can be expired

• FEV1/FVC%: AKA (FER) that is forced expiratory ratio. The FEV1 is presented as a percentage of FVC

• MMEF or FEF25-75%- Maximum Mid Expiratory Flow, decreased in obstructive lung disorders with a concaving pattern of the loop

Spirometry Testing

• Simple brief instructions, followed by prompts during testing in a timely manner.

• Deep breath in and blast out with no pause or hesitation, hard and fast

• Continuous encouragement to keep exhaling is very important

• Then take hard fast deep breath in before coming off the mouthpiece

Phases of Spirometry

Spirometry Testing

• Take a deep breath in..

• Without any pause blast out…

• And keep breathing out….

• Keep going until six seconds reached or patient unable to breath out any further.

• Encourage patient right through the trial…then take a deep breath in and catch your breath.

Acceptability 1

Slow start?

Acceptability 2

Acceptability 3

Acceptability 4

• Short blow with normal ratio and restrictive indication

Acceptability 5

Acceptability 6

• Same patient with much long breath out

Acceptability 7

Acceptability 8

Acceptability 9

Acceptability 10

Acceptability

• No Coughing

• No Hesitation

• No obstruction of mouthpiece

• Full inspiration prior to forced expiratory maneuver

• Maximum efforts required

• No Glottic closure

• No Closing teeth or loose dentures

• Good seal with lips around the mouthpeice

Acceptability

• A full big breath in..

• Good start that is no hesitation

• No cough in 1st second

• Exhalation for 6 - 15 seconds or 3 seconds for children

• No leakage or obstruction

Repeatable

“3 REPEATABLE trials”

• 2 Largest FVC within 0.15 l of one another

• 2 Largest FEV1within 0.15 l of one another or within 0.10 l if FVC ≤ 1.00 l.

(not necessarily from the same attempt)OR

• 8 trials (exhausted!) - use the best 3

Repeatable 1

Repeatable 2

Repeatability

Acceptable and Repeatable?

Acceptable?

Repeatable?

Acceptable?

Acceptable?

Acceptable?

Repeatable?

Acceptable?

Repeatable?

Not getting consistent trials

• Review the trials

• Let patient know where the mistakes are, cough, hesitation, slow start or not blast hard enough etc

• Give time in between trials

• If you don’t want to perform test it will reflect on results

• Encourage patient and be enthusiastic

Try different dialogues

• Describe what is expected

• If possible demonstrate

• Explain nod emphasize the fact that this is not a relaxed test

• Exertion maximally is main part and holding the forceful breath out also as important

Timing

• Timing is everything,

• Pause in your instruction will reflect with either hesitation or pause on the test results

• Review the flow volume loop as the test is being done

• Keep encouraging right through the procedure

Spirometry

• Simply

• Describe

• Demonstrate and get patient to

• Do the test

• ☺