clinical skills session without slide 4

Clinical Skills Session

Update day March 2016

Non-vis rates………. Myths Sonosite machines have higher non-vis rates than GE machines

• The non-vis rates are very similar • The sonosite has less functionality • One of the reasons for it being chosen • Newer machines do have better imaging at depth but not sufficient to

warrant new machines as yet Areas with high non-vis rates have higher levels of obese patients

• All screening programmes have mixed degrees of socio-economic and ethnic backgrounds

• Very similar across the country • No obesity epidemic within Oxfordshire

Part time staff have higher non-vis rates than full time staff • Very similar rates across the programmes • May take longer time to stabilise once training has been completed

• High non vis rates are usually down to technician confidence at measuring the aorta at depth

• National average is 1.43%

• Achievable standard is 3.0%

• NAAASP are looking at reducing the threshold for non-visualisation

How to improve the images….. • What’s the point?

• Hopefully reduce the non-vis rates • Provides a better service to the subjects being screened • Improves performance and cost effectiveness of the programme • Ensures that the screening programmes and technicians are

providing a quality service to the community based on quality standards that can be measured

• May seem like a blunt tool

• Every image should be optimised before taking a measurement • The images on obese patients will never be as good as those on

slimmer patients • Use the non-vis guidance

4 Thames Valley Update 12/11/14

• Increase depth • Sounds counter intuitive • Sonosite machines have the focal zone in the middle of the screen

• Decrease the dynamic range • Reduces the number of shades of grey and therefore should help

highlight the vessel walls • Can be reduced to -3 in obese patients on sonosite • Alter as much as required on the other machines

• Reduce the frequency of the probe/ultrasound • Reducing the frequency of the probe will increase the wavelength • Improves penetration • Reduces image quality


• Remove harmonic imaging • Improves the frame rate • US machine has to wait less time before acquiring the

image • Can make image worse

• Remove compound imaging • Improves frame rate • Can make image worse • Always adjust the gain when taking this on or off


• Press harder • Brings aorta nearer to the probe • Mindful of patient comfort level

• Image in transverse • Easier to image in transverse • Think of transverse as your friend • If you get stuck rotate probe

• Don’t get obsessed with anterior vessels or IVC • Might not see them in obese patients • 50% visualisation rate


• Use two hands to press the probe down • Mindful of MSK injury • Get colleague to freeze

• Get patient to breath in and hold breath • Relaxes the diaphragm • Push probe down when breathing in

• Stop the scan • Get colleague to have a look • 2 mins away can give you different perspective • Know your limitations


Hints and tips Increase depth

Decrease dynamic range

Reduce frequency of the probe

Remove harmonic imaging

Remove compound imaging

Press harder

Transverse imaging

Anterior vessels

Use two hands

Get patient to breath in, hold it and then breath out

Ask colleague to look/take a break/know when to stop

Tell patient to wait outside

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clinical skills session without slide 4

Healthcare