Muscular contraction compresses the veins, causing blood to return to the heart. When an extremity is paralyzed, this muscle pump action isn't present. The compromised venous blood flow may increase the risk of thrombosis at the site of venipuncture and infusion. Palpation will provide valuable information about the vein condition. Veins in a well-hydrated patient should distend easily within 3 to 5 seconds.
Dehydrated patients require a longer period.
A good palpation technique involves constantly using the same finger to feel the vein's condition. You'll develop an increased sensitivity in that finger, which will enable you to palpate veins that may otherwise go unnoticed. With your finger, press down on the distended vein. As you release the pressure, a healthy vein will rebound easily with a resilient elasticity. Sclerotic veins will feel hard or cord-like.