Figure 6-1. Veins in the forearm and hand (right arm).
(5) If you have difficulty finding a vein, lower the arm below the level of the
heart. If you still cannot find a vein on the arm or hand, try to find a vein on the foot. If
this fails, try to find a vein on the leg.
Attempt to penetrate the vein at the most distal point (the one closest to the
end of the extremity) that is practical. If you are unsuccessful the first time,
move toward the heart for your second attempt.
c. Apply Constricting Band. Apply the constricting band (tubing) about 2
inches above the selected infusion (venipuncture) site in such a manner that the band
can be released using only one hand.
The purpose of the constricting band is to stop the blood in the vein from
flowing back to the heart. This causes the vein to enlarge and become easier
to locate. The constricting band should not be applied so tight that the arterial
blood flow stops. The casualty should still have a radial pulse after the
constricting band had been applied.