Peak flow / Spirometry Flashcards
What is peak flow?
Measures how quickly you can blow air out of your lungs
What counselling is given to a patient when taking a peak flow reading?
Take your peak flow before using the preventer inhaler
Always use the same peak flow meter
What factors can cause variation in a normal peak flow?
Age
Height
Gender
What would diurnal variation suggest?
Asthma
Poor control of pre-existing condition
What would a low score avg suggest?
Narrowed airways
What is spirometry?
Method to assess lung function
Measures the vol of air a person is able to expire after maximal inspiration
Measures functional lung volumes.
What is spirometry used for?
To diagnose and monitor certain lung diseases
Distinguishing between obstructive and restrictive lung disease
What is FEV1?
Vol exhaled in 1sec after deep inspiration + forced expiration
FORCED EXPIRATION IN 1 SEC
What does FEV1 depend on?
Age
Sex
Height
Mass
Ethnicity
What is FVC?
Total vol of air that a person can forcibly exhale in 1 breath
FORCED VITAL CAPACITY
What are the predicted % based on?
Predicted normal for a person of the same sex / gender, age, ethnicity and height
What would an obstructive picture on spirometry look like?
FEV1 < FVC
FEV1/FVC < 0.7
FEV1 < 80% predicted.
FVC is lower but not as low as FEV1
Why does obstructive spirometry have that pattern?
Takes a long time to exhale (wheeze) so not much breathed out at 1 second but volumes not bad overall.
Give examples of Obstructive lung diseases that are :
a) Reversible
b) Irreversible
c) other causes?
a) Asthma
b) COPD
c) CF, emphysema, bronchiectasis, inhaled foreign body and
tumour
What would an restrictive picture on spirometry look like?
FEV1/FVC > 70% w/ FEV1 + FVC being <80% predicted
Why does restrictive spirometry have that pattern?
Restriction, lung volumes are small and most of breath is out in the first second.
True or False:
- restrictive lung diseases are usually diseases of the interstitial affecting chest wall movement and elasticity
True
Give some pulmonary causes of restrictive lung disease
Pulmonary fibrosis
Pneumoconiosis
Pulmonary oedema
Lobectomy / Pneumonectomy
Parenchymal lung tumours
Give some non pulmonary causes of restrictive lung disease
Skeletal abnormality - Kyphosis
NMD - MND / Myasthenia gravis / Guillain-Barre syndrome
Connective tissue disorders
Obesity
Pregnancy
What focused questions would you ask about medications?
Adherence to tx
current meds
inhalers they use and how often
other medications?
any beta blockers?
SE?
check inhaler technique
check inhaler use has been assessed by the nurse.
What focused questions would you ask about SHx?
Any (new) pets?
Recent travel anywhere?
- Particularly to places that are polluted.
Housing situation(damp)?
Hayfever.
Smoking? Alcohol? Impact of condition on life.
What red flags would you ask about?
worsening wheeze
Affecting ADLS
waking up at night w/ sx (SOB, cough)
using reliever inhaler more than usual
Any other questions you would ask?
recent illnesses / infection
SOB?
worse at any specific time?
What advice would you give a patient?
Stop / reduce smoking
Avoid precipitants
Vaccinations - flu / COVID 19
Exercise
Eating
Support
