Nurses often have many different duties which they perform to help doctors take care of patients, especially in a hospital setting. One of the duties of nurses in hospitals is to insert intravenous, or IV lines and maintain those lines. This includes checking the patency of the line before hooking a patient up to IV treatments.

Meaning of Patency

When a patient requires an IV for medical treatment, it is usually a nurse's job to insert the IV and administer the treatment as ordered by the doctor. Once the IV line is inserted, the nurse must check the line for patency. In simple terms, this means that the line is open and not blocked. A patent IV line is one that is correctly placed, allowing the treatment to flow directly into the patient's vein. A poorly placed IV is not patent and can cause negative side effects.

IV Insertion

Placing an IV is done in much the same way as blood is drawn. The nurse uses a tourniquet to find an appropriate vein in which to insert the cannula. She inserts a needle into the patient's vein until a small amount of blood appears in the cannula. At this point, the nurse removes the needle, leaving a small catheter in place in the vein, granting access to the IV fluids. She tapes the cannula to the patient's arm to keep it from backing out or moving. The nurse must then check for patency before administering the treatment.

Checking Patency

Once the IV line is in place, the nurse checks the line for patency to ensure that the line is properly placed and the fluids will flow into the vein as intended. To check for patency, the nurse inserts a syringe filled with saline solution, which is a mixture of salt and water, into the cannula. She gently injects a small amount of the saline solution into the cannula, checking for appropriate flow. During this process, the nurse should check for resistance, which can indicate blockage, and pain or swelling of the skin at the site of the IV line.

Lack of Patency

If a nurse discovers that the IV line is not patent, either upon initial insertion -- or over the course of the IV treatment -- the line must be moved. While this can be frustrating and upsetting to the patient, as well as the nurse, it must be done to ensure that the treatment is successful. If the IV line is not patent, the nurse removes the cannula from the patient and begins the insertion process again. The cannula cannot be replaced in exactly the same spot, so the nurse may try a different spot on the same arm or try the other arm. In some cases, patients with hard-to-find veins may be subject to several cannula insertions before finding one that is patent.