The Hepatitis C Pilot
Lynnaire Matthews, Community Hepatitis Nurse
I www.hepatitisfoundation.org.nz I 0800 33 20 10
Community Assessment and Support (CAS) Programme
I www.hepatitisfoundation.org.nz I 0800 33 20 10
CAS Programme Working in partnership with other service providers to provide care, including: •
Initial assessment
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FibroScan®
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Appropriate tests and follow-up
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Treatment options
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Lifestyle changes
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Multidisciplinary meetings (MDMs)
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Long term follow-up or long term support
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GPs kept up-to-date on their patients’ plan of care (with patient consent)
Staging Liver Fibrosis by Transient Elastography (Fibroscan)
www.hepatitisfoundation.org.nz I 0800 33 20 10
Fibroscan in Wellington Pilot •
Community assessment and support programme, including the Fibroscan service, began November 2013 in Greater Wellington Region
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It is a Nurse led community service
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More than 250 examinations performed using the portable Fibroscan
The Examination •
A mechanical pulse is generated at the skin surface, creating a shear wave which is propagated through the liver.
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The velocity of the shear wave is measured by ultrasound.
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The velocity of the shear wave is directly correlated to liver stiffness (fibrosis).
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Result is delivered at the end of 10 acquisitions – measurement expressed in kPa
The Probe
Ultrasonic transducer emits and receives ultrasound waves
Button
Vibrator generates the shear elastic wave
What is elasticity (stiffness)? Quantify the ability of a medium not to get out of shape when under mechanical stress 10000000000 1000000000 100000000
Stiffness (Pa)
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10000000 1000000
Bone Cartilage Muscle Cirrhotic liver
100000 10000 1000 100 10 1
Breast Normal liver
How do we measure stiffness? •
In soft tissues, stiffness is related to the velocity of elastic waves that are named shear waves
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Shear waves are widely present in biological tissues…
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The stiffer the tissue, the faster the shear waves Generate a shear wave within the liver Measure its speed of propagation VS Elasticity E ∝ VS2
Patient’s positioning
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Patients in dorsal decubitus and the right arm in maximal abduction.
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Measurement on the right lobe of the liver between the rib bones.
10
Probe positioning •
Place the probe between the rib bones opposite to the right lobe of the liver in the middle of the parenchyma far from the border of the liver. If you are too close to the borders the liver stiffness will be overestimated.
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The location where the liver biopsy would be performed should suit. Dullness at percussion Sternum and mid axillary line
No O
K
No
11
Ultrasonic imaging M
S1/S2
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10 20 30 40 50 60 70 80 Time (ms)
20 25 30 35 40 45 50 55 60 65 70 75 80 0
Depth (mm)
20 25 30 35 40 45 50 55 60 65 70 75 80 0
Depth (mm)
Depth (mm)
Examples in human liver
10 20 30 40 50 60 70 80 Time (ms)
VS = 1.1 m/s
VS = 1.7 m/s
No fibrosis
Significant fibrosis
E ~ 3 kPa
E ~ 9 kPa
20 25 30 35 40 45 50 55 60 65 70 75 80 0
10 20 30 40 50 60 70 80 Time (ms)
VS = 3.6 m/s E ~ 40 kPa
Cirrhosis
Technical causes of stiffness overestimation •
Region of measurements is too close to the border of the liver (interferences and capsula)
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Liver is located too deep below the skin surface (overweight patients)
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Tip of the probe in contact with a rib bone (narrow intercostals space or probe resting against a rib)
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Probe not perpendicular to the skin surface (operator’s responsibility)
14
Interpreting Results •
Is this a valid examination?
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10 valid readings, > 60% success rate, IQR < 30%
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Is the ALT >200
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Is the probe size the right match for patient size?
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Does the result ‘fit’ the clinical picture?
FibroScan reveals the numbers with Cirrhosis Fibroscans to September 2013 n = 254
Severe fibrosis 6%
Cirrhosis 17%
No or mild disease 77%
Referral process Referrals can be sent to the Foundation via: •
Your online health network / e-referral (where available);
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Contacting the Foundation: •
Email:
[email protected];
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Fax: 07 571 2548;
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Website: www.hepatitisfoundation.org.nz;
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Post: PO Box 15 347, Tauranga;
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Phone: 0800 33 20 10
Together we can confront hepatitis C. Know it. Test it. Treat it.
The Hepatitis Foundation of New Zealand I www.hepatitisfoundation.org.nz I 0800 33 20 10
Thank you
The Hepatitis Foundation of New Zealand I www.hepatitisfoundation.org.nz I 0800 33 20 10
