Aspergillosis Patients Support Meeting June 2011 - Nigel Clayton

Led by Graham Atherton
Supported by
Georgina Powell, Marie Kirwan & Debbie Kennedy
NAC Centre Manager Chris Harris
Talks given by Nigel Clayton
Lung function facility
North West Lung Centre
UHSM, Manchester
National aspergillosis centre
UHSM
Manchester
Support Meeting for Aspergillosis Patients
Fungal Research Trust

Welcome to Wythenshawe Hospital

Blow me down !
Did you know:
A fit healthy person will breathe more than 270 million litres of air in a lifetime. This is equal to 90 Olympic swimming pools!
The lungs contain more than 300 million air sacs called alveoli.
If your lungs could be opened up and laid flat they would cover the area of a tennis court.
Children whose parents smoke are 1.5 times more likely to suffer from asthma.
Lung disease kills 30,000 people a year in the UK.
Smoking is the single largest preventable cause of death and illness in the UK.
Asthma is the most common chronic disease of childhood, with 1 in 7 children in the UK having a diagnosis of asthma.

Lung function testing
Why we do it
How we do it
What does it all mean?
Nigel Clayton
Respiratory Physiologist
Wythenshawe Hospital

What is Aspergillus?
Aspergillus is a fungus whose spores are present in the air we breathe
It does not normally cause illness
However an individual with a weakened immune status may be susceptible to aspergillus infection

What is Aspergillosis?
Aspergillosis describes a number of diseases involving both infection by and growth of the aspergillus fungi, as well as allergic responses against aspergillus.
Aspergillosis can occur in a variety of body organs, in both humans and animals. Infections can effect any area of the body, but by far the most common are the lungs and sinuses.
Aspergillosis includes allergic bronchopulmonary aspergillosis (ABPA), aspergilloma and invasive pulmonary aspergillosis (IPA)
Incidence rate of 1-2 per 100,000 per year.

Diagnosis
Depending on patient history a number of tests may be requested from the following list:
A blood test - Specific IgE (allergy) test
A skin test to measure sensitivity to Aspergillus allergens
X-rays or CT scan of the chest
Culture and analysis of a sputum (mucus) sample
Culture of tissue fluids e.g. lung fluid called bronchoalveolar lavage (BAL)
A bronchoscopy – where a flexible tube is passed down into
the lungs to sample or biopsy a tissue mass (if present) in a lung cavity
Lung Function Tests

The Respiratory System
Main function to supply the body with O2 and remove CO2
Respiration is actually 4 distinct processes:
Ventilation – Movement of air into & out of the lungs
External Respiration – Gas exchange between blood and air-filled chambers of the lungs
Transport of Gases – Cardio-vascular circulation
Internal Respiration – Gas exchange between systemic blood and the tissue cells

Respiratory Zone
Defined by the presence of thin-walled air sacs called alveoli.
Begins at the transition from terminal bronchioles to respiratory bronchioles – which contain scattered alveoli.
Respiratory bronchioles become alveolar ducts which lead into terminal clusters of alveoli called alveolar sacs.

Respiratory Zone

Lung Function Tests measure
How much air you can take into your lungs. This amount is compared to that of other people your age, height, and sex. This allows your doctor to see whether you're in the normal range.
How much air you can blow out of your lungs and how fast you can do it.
How well your lungs deliver oxygen to your blood.
How strong your breathing muscles are.

What is the purpose of a lung function test?
To detect the general type and severity of a lung disorder rather than defining the specific cause of problems
Useful for assessing change in lung function over time (improvement / deterioration)

Lung Function tests most often used
Spirometry. This test measures how much air you can breathe in and out. It also measures how fast you can blow air out.
Lung volume measurement. This test, in addition to spirometry, measures how much air you have left in your lungs after you breathe out completely.
Lung diffusing capacity. This test measures how well oxygen passes from your lungs to your bloodstream.

Tests to Measure Oxygen Level
Pulse oximetry and arterialised blood gases are two tests used to measure the oxygen level in the blood. They're also called blood oxygen tests.
Pulse oximetry measures blood oxygen levels using an infrared light.
If the pulse oximeter oxygen level is less than 95% the physiologist will often take a sample of blood from the earlobe. A more accurate check can be made of the oxygen level and carbon dioxide level (waste gas).

Measuring Oxygen Saturation
Pulse oximetry measures blood oxygen levels using an infrared light. Heart rate may also be monitored.

Arterialised Blood Gas Test
Measures the oxygen and carbon dioxide levels in arterial blood

Spirometry
FEV1 / VC ratio = 4.2 x 100 = 88%
4.8
5
4
3
Volume (L)
2
FVC 4.8
FEV1 4.2
1
0
1
6
2
3
4
5
Time(s)

Spirometry

Practical
Spirometry measurement showing:
Volume against time
Flow against volume

Cross-Sections of Bronchioles
Normal
Mucus
Bronchospasm
Inflamation

Question:
How much faster will container A
empty compared to container B ?
A
B
2 cm
1 cm

Volumes and Capacities

Practical
Lung volume measurement using oxygen breathing to washout and measure the volume of air in the lungs

Diffusion
The passive tendency for molecules to move from a region of high concentration to a region of lower concentration.
ie from area of high pressure to area of low pressure.
The process requires no energy or chemical reactions and is caused by movement of molecules of gas in a random fashion.

Practical
Gas transfer measurement using carbon monoxide

Obstruction
Severe
FEV1 29% predicted
Marked scooping on FV loop
Hyperinflation
increased FRC, RV and RV/TLC%
Ventilation / perfusion mismatch
Reduced DLCO
Reduced KCO
Hyperinflation confirmed
by body box data
Low PO2, normal PCO2

Thank you

Aspergillosis Patients Support Meeting June 2011 - Nigel Clayton

by Graham Atherton

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Aspergillosis Patients Support Meeting June 2011 - Nigel Clayton Presentation Transcript