Evolution of Catheter
Tip Placement Technology
Landmark: Blind placement with chest X-ray confirmation
The current "landmark" technique for PICC placement has not changed significantly in more than three decades. Clinicians routinely place the PICC using external landmarks and approximate measurement at the bedside. The location of the catheter tip must be confirmed by chest X-ray (CXR). When using the landmark technique, clinicians have a 65-75% success rate of placing the catheter tip within the lower 1/3 of the SVC-CAJ on the first attempt, with a tolerance of ± 6.25 cm from the CAJ2,3,4.
Chest X-ray
Although the current "gold standard" to confirm catheter tip placement is the chest X-ray (CXR), there are several limitations with this technique:
- Time to read and clear
- Delays in time to therapy
- Workflow problems for vascular nurses
- Poor image quality
- Variations in landmarks and anatomies
- Central catheter tip position outside of optimal zone
- Procedural repetitions due to malposition
Magnetic: External system for locating catheter tip
Some newer systems use external devices to approximate the location of the magnet tip of a stylet. Based on the literature, clinicians have a first attempt success rate of up to 80%.3 However, external magnetic systems can only provide an approximate location of the catheter tip relative to the lower 1/3 of the SVC-CAJ, and cannot provide real-time feedback when the catheter is against a vessel wall, or in an artery or azygos vein. Operation of these systems may be affected by electromagnetic interference. Certain patient types present challenges, including obese patients or patients with pacemakers. Additionally, the patient must be able to tolerate the external location device resting on the chest and must remain motionless throughout the procedure. This may create a significant amount of discomfort to the patient.
ECG Only: Physiological system with limited capability
This method uses limited physiological information. Studies report that clinicians have a first attempt success rate ranging from 50%-88% with a tolerance of ± 3.5 cm from the CAJ.4 However, since a normal sinus rhythm is required for this method to work, patients who had an abnormal P-Wave were excluded from these studies. Therefore, patients with atrial fibrillation, pacemakers, heart failure or myocardial pathology — approximately 1 out of 11 people in the U.S. — may not be able to benefit from this technology.