A quick look at the Modified Seldinger

The Modified Seldinger technique provides nurses with another option to place a peripherally inserted central catheter (PICC) when venous access is poor. Deborah Richardson, RN, MS, CNS, clinical nurse specialist for the Infusion Therapy Team at MD Anderson Cancer Center in Houston, offers PICC classes that include the technique. Richardson gives the following step-by-step method for the Modified Seldinger technique.

1. Verify the physician order to insert.

2. Explain the procedure to the patient and obtain informed consent, if required.

3. Assess and select a vein. Determine whether the vein is adequate for a PICC, and if so, if it is adequate for the introducer that comes with the catheter. If the introducer is not adequate, opt for the Modified Seldinger technique.

"The original introducer that comes with the PICC is your first choice for cannulating the vein and threading the catheter into place," notes Richardson. "However, many times the original introducer is larger than the patient's vein, so there has to be an alternative available to the health care provider in an attempt to place the PICC catheter."

Richardson notes that using the Modified Seldinger technique allows the nurse or doctor to cannulate the vein while decreasing the risk of blowing the vein from a larger introducer and still allowing the catheter to be threaded into place. This method uses a small-gauge needle and a flexible guide wire with a soft, straight or "J" tip.

4. Gather the appropriate supplies and equipment required for the Seldinger procedure. The equipment may include any of the following: insertion tray, catheter kit, linen protector, sterile gown and gloves, mask and shield, selected small-gauge needle for accessing the vein, and a tourniquet.

5. Wash hands and position the patient appropriately.

6. Determine catheter length.

7. Open trays aseptically; set up sterile field.

8. Prep insertion site according to established company policy.

9. Remove gloves.

10. Put on mask, sterile gown and gloves.

11. Rinse gloves in sterile saline or sterile water.

12. Measure and trim catheter if needed.

13. Place sterile drapes.

14. Tighten tourniquet.

15. Depending on the institution, local anesthetic may be given. At MD Anderson, Richardson notes that she normally draws up 5 cc of 1% lidocaine to anesthetize the insertion site area. Then, 1-2 cc lidocaine is injected subcutaneously at the skin puncture point.

16. Using the introducer or small-gauge peripheral catheter, cannulate the vein and obtain a flashback of blood. Release the tourniquet. If using an over-the-needle catheter (i.e. angiocath), thread the angiocath into the vein and remove the stylet.

17. Insert a short, flexible wire through the needle/angiocath approximately 8-10 cm into the vein. Remove the needle or angiocath, leaving the guidewire in place. Be sure to hold onto the wire at all times. This short wire maintains the site location for inserting the catheter.

18. Enlarge the puncture site and slide a dilator with a peel-away sheath over the wire.

19. Remove the wire and dilator, leaving the peel-away sheath in place. The MD Anderson catheter tray includes: the catheter with wire stiffener as one unit, introducer needle (18 gauge), dilator with peel-away sheath, 10 cc syringe, injection cap, and short wire.

20. The catheter, which has been rinsed with sterile saline to wash off particulate matter and allow it to slide better, is threaded through the peel-away up to the catheter hub. The peel-away unit is peeled in half. As you split the peel-away sheath, the catheter may slide back a little. Simply push the catheter back in up to the hub.

21. Once the peel-away is removed, the catheter is left in place. Pull the wire out of the catheter and aspirate for a blood return. Flush the catheter with normal saline and heparin lock. At MD Anderson, a 250 cc bag of normal saline is connected to the catheter to infuse while the catheter is sutured into place.

22 The puncture site is cleansed with povidone iodine solution and dried.

23. Povidone ointment is placed on the sutures and site, and a sterile dressing is applied.

24. Obtain a chest X-ray to verify catheter tip position.

Richardson notes that the difference between the traditional Seldinger technique and the Modified technique is that the Modified technique allows the nurse to thread the catheter through a peel-away sheath, while the traditional technique calls for the nurse to thread the catheter over the wire (the wire would need to be at least two-and-a-half times the length of the catheter.) As a result, the Modified Seldin ger technique decreases potential cardiac problems for the patient because a long wire is not used, and promotes a more controlled sterile environment.