An intermittent infusion injection device, or saline lock, allows I.V. administration without the need for multiple venipunctures or continuous I.V. infusion. Saline solution is typically injected as the final step in this procedure to prevent clotting in the device.
Patient's medication record and chart 
gloves alcohol pads three 3-mL syringes with needleless adapter normal saline solution extra intermittent infusion device prescribed medication in an I.V. container with administration set and needle (for infusion) or in a syringe with needle (for I.V. bolus or push) tourniquet tape optional: T-connector, sterile bacteriostatic water.
Verify the order on the patient's medication record by checking it against the doctor's order. Perform hand hygiene and then wipe the tops of the normal saline solution and medication containers with alcohol pads.
Fill two of the 3-mL syringes (bearing 22G needles) with normal saline solution.
Pump it up
If you'll be infusing medication, insert the administration set spike into the I.V. container, attach the needleless adapter, and prime the line. If you'll be giving an I.V. injection, fill a syringe with the prescribed medication.
Confirm the patient's identity using two patient identifiers. Explain the procedure.
Don gloves and wipe the injection port of the intermittent infusion device with an alcohol pad. Then insert the needleless adapter of a saline-filled syringe.
Aspirate the syringe and observe for blood to verify the device's patency.
Puffiness or pain?
If you feel no resistance, watch for signs of infiltration (puffiness or pain at the site) as you slowly inject the saline solution. If these signs occur, insert a new intermittent infusion device.
If blood is aspirated, slowly inject the saline solution and observe for signs of infiltration.
Withdraw the saline syringe and needleless adapter.
Administering I.V. bolus or push injections
Insert the needleless adapter and syringe, inject the medication at the required rate, and remove the needleless adapter and syringe.
Insert the needleless adapter of the remaining saline-filled syringe into the injection port and slowly inject the saline solution to flush all medication through the device.
Remove the needleless adapter and syringe.
Administering an infusion
Insert and secure the needleless adapter attached to the administration set.
Open the infusion line and adjust the flow rate as necessary.
Infuse medication for the prescribed length of time, then flush the device with normal saline solution, as you would after a bolus or push injection, according to your facility's policy.
If you're giving a bolus injection of a drug that's incompatible with saline solution, such as diazepam (Valium), flush the device with bacteriostatic water.
Intermittent infusion devices should be changed regularly (usually every 48 to 72 hours) according to standard precautions guidelines and your facility's policy.
If you can't rotate injection sites because the patient has fragile veins, document this fact and discuss it with the patient's doctor. (See Documenting intermittent infusion devices.)
Outline