Peripheral access: centre the dot

Question 1Why do you centre the vein on the screen before puncture?

1. aIt lets you use a lower frequency
2. bIt removes the need to look at the needle
3. cA centred, round vein gives a predictable needle path to the target
4. dIt makes the vein look larger than it is

Question 2What is the dynamic check before puncture?

1. aSlide a short way along the vein and back, keeping the same vein centred and round
2. bAsk the patient to clench the fist
3. cTilt the probe until the artery is visible
4. dPress hard to see whether the vein disappears

Question 3The vein sits at the edge of the screen and looks flat. What do you do first?

1. aSlide to centre it, reduce the pressure until it is round, then recheck
2. bPuncture now, as the vein is shallow
3. cSwitch to the artery as the target
4. dIncrease the pressure to hold the image still

Question 4In which patients does ultrasound guidance help most for peripheral cannulation, according to the 2022 Cochrane review?

1. aEvery patient, by the same amount
2. bOnly children
3. cAdults with easily seen veins
4. dAdults with moderately difficult or difficult access