Which Techniques Will Encourage a Vein to Dilate in Preparation

Which techniques will encourage a vein to dilate in preparation for a blood draw? (Select all that apply.)

A) Hold the extremity below the level of the heart.
B) Have the patient make a fist and release it repeatedly.
C) Tap the vein lightly or stroke it in a distal direction.
D) Apply cool, wet compresses for 10 minutes.
E) Put on a tourniquet 2 or 3 minutes before venipuncture.