Arm-to-Tongue Circulation Time

 

Method:

(1) A venipuncture is performed on a vein in an antecubital fossa using a 20 gauge needle or larger.

(2) 5-10 mL of a solution with a dissolved marker is quickly injected and a stopwatch started.

(3) The stopwatch is stopped when the patient first detects the marker effect.

 

Markers:

(1) bitter taste: sodium dehydrocholate (decholin = 20% dehydrocholic acid)

(2) fluorescent dye causing fluorescence of papillae

(3) hot or burning sensation: 10% magnesium sulfate

 

Interpretation:

• The normal time ranges from 9 to 16 seconds.

• An increase in the circulation time is seen in heart failure.

 

Limitations:

• A patient with dysgeusia may have a longer circulation time for a bitter marker due to delayed perception.