Chapter 10 - Digital pressure and plethysmography

Question 1

Technique for toe plethysmography

Answer 1

1) Supine or head elevate up to 20 degrees
2) Cuff width >1.2x of toe applied to base (2-2.5 cm for most, 2.5-3cm for big toe)
3) Pressure volume curve recording
4) Note pulse recording at rest
5) inflate until no pulsation noted (20-30 mmHg above ankle pressure) - volume increase due to venous obstruction
6) pressure at which first volume spike noted = toe pressure

Question 2

Cuff width for fingers and toes and Big toe

Answer 2

> 1.2x
2-2.5 cm for most
2.5-3 cm for big toe

Question 3

Cold provocative test steps

Answer 3

1) resting study
2) immerse in ice water for 3 minutes
3) dry and test again immediately
4) test again 5 minutes after

Question 4

normal plethysmographic waveform quality

Answer 4

1) sharp upstroke
2) prolonged downstroke with dicrotic notch half way down
3) amplitude finger > toe

Question 5

Abnormal obstructive plethysmographic waveform quality

Answer 5

1) Slow upslope
2) rounded peak
3) downslope that bows away from baseline

Question 6

Abnormal peak plethysmographic waveform quality

Answer 6

1) slower upslope
2) sharp anacrotic notch
3) dicrotic notch high on downslope
4) characteristic of both normal and obstructive waveform

Question 7

Normal finger/brachial index

Answer 7

0.8-.09

Question 8

Normal toe/brachial index

Answer 8

0.6-0.8

Question 9

Difference between diabetic and nondiabetic in ankle and toe pressure

Answer 9

Diabetes affect ankle not toe

Question 10

Digital waveform difference in Raynauds phenomenon vs true vasospasm

Answer 10

Raynauds have peaked pulse described by Sumner Strandness

True vasospasm has normal contour but decreased amplitude