The right vein To choose the correct vein, you need to know the patient's medical history and you must palpate the vein's condition. Previous surgery or injuries may increase the risk of infiltration, extravasation, or thrombosis if you place the catheter in the affected extremity. Lymphedema after mastectomy, enlarged lymph nodes, and thrombosis may alter venous blood return. If you use these veins for infusion, the increased pressure may cause retrograde flow and cause fluid to leak from the insertion site. Normal venous blood return depends upon the muscle pump action.
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 thrombosis risk 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.