Transcranial Doppler

2 mHz

• 1.) Decrease power output
• 2.) Shut eye

• 1.) No response or reaction
• 2.) Flow increase
• 3.) Flow decrease
• 4.) Reversal of flow
• 5.) To-Fro pattern
• 6.) Total cessation of flow

PI = PSV - PEDV / Mean velocity

0.80 to 1.20

Lower pulsality

• 1.) stenosis of the supplying artery
• 2.) AVM feeders

Higher pulsality

• 1.) Larger aneurysm
• 2.) Increased intracranial pressure
• 3.) Microvascular disease

PI decreases

• 1.) < 80cm/sec = normal
• 2.) 80-120 cm/sec = moderate spasm
• 3.) 120-140 cm/sec = severe spasm
• 4.) > 140 cm/sec = severe causing lots of damage

Normal- sharp high resistance, low volume, low velocities

Abnormal- Dampened waveform

• 1.) Radiosurgery
• 2.) Endovascular treatment

• 1.) increased flow velocity
• 2.) reduced pulsatility
• 3.) reduced responsiveness to CO2

vertically

horizontally

velocities throughout the scan field

strength of the Doppler shift from each location.

Ignores velocity

• 1.) sensitive to slow flow
• 2.) never aliases
• 3.) angle does not effect it

• 1.) cannot determine direction
• 2.) frame rates drop

how many sample areas per a line

how many lines in the color box area

The American Institute of US in Medicine

1.) The distance from the echo to the transducer

2.) strength of the echo

1.) Doppler shift information

2.) Time of flight

3.) amplitude information

a flash of color within the soft tissue caused by the vibration of the vessel caused by severe flow disturbances

significant stenosis of the end branches of the ICA.

1.) can't find exact location of stenosis or differentiate stenosis from occlusion.

2.) Hard to find when collaterals are working

take brachial pressures first

• 1.) allergies to local anesthetics
• 2.) eye surgery within the last 6 months
• 3.) a past spontaneous retinal detachment
• 4.) acute or unstable glaucoma

measuring the ophthalmic artery systolic pressure by applying a vacuum to the eye on the sclera (white of the eye).

<140 mmHg = 300mmHg

>140 mmHg = 500mmHg

a difference of 5mmHg between eyes

transcutaneous oximetry

1.) non-invasive monitoring of the oxygen tension in the skin

2.) direct indication of the microvascular function

1.) neonatal use

2.) vascular care

3.) wound care

• 1. Diagnosis of ischemia
• 2. Healing probability
• 3. Suggesting amputation level
• 4. Plastic surgery
• 5. Hyperbaric medicine
• 6. Orthopedic surgery
• 7. successful revascularization
• 8. PVD assessment

• 1. Uses polarographic oxygen electrode
• 2. Electrode heats skin to 44-45 degrees Celsius
• 3. Oxygen is consumed by the electrode
• 4. Electrode is calibrated with gas or with a solution of known PO2

room temp. 70-73 degrees F.

• 1.) no caffeine 30 minutes prior to test
• 2.) no smoking 30 min prior to test
• 3.) no talking during test
• 4.) no excessive movement during test

• 1. ulcers
• 2. cellulitis
• 3. skin close to bone
• 4. large superficial vessels
• 5. pulse sites

1. 70-80 mmHg = healing

2. 30-40 mmHg = borderline healing

3. 10-15 mmHg = non-healing

used to determine if flow will be laminar or turbulent

• <2000 = no turbulence
• >3000 = turbulence

Primary

Caused from cold or stress.

Secondary Raynaud's

• Underlying conditions:
• stenosis, systemic lupus, carpal tunnel

White to Blue to Red