Abstract:

Objective To investigate the effect of magnetic field on guide wire during subclavian vein catheterization (SVC) and decrease the rate of misplacing a catheter. Methods A magnet field model of vein catheterization was built. The magnet field guide method was used to avoid misplacing a catheter, i.e. the direction of guide wire was guided by the attraction of a NdFeB magnet. The effects of different venous angles, wire tips, and directions under the action of magnetic field on the successful puncture rate were explored. Results A NdFeB magnet placing 46 mm away from veins could increase the successful puncture rate when the venous angle was not less than 110° and the ‘J’ tip turned towards the brachiocephalic vein, as well as when the venous angle was less than 110° and ‘J’ tip turned towards the chest. However, the magnet had no effect for any venous angles when ‘J’ tip turned towards the back. The successful puncture rate was increased for some venous angles when ‘J’ tip turned towards ipsilateral internal jugular vein. The effective area for magnet-guided SVC was an 80 mm by 90 mm rectangle with one short side close to the venous junction and two long sides being about 40 mm away from the brachiocephalic vein. Conclusion The presence of magnetic field during SVC can effectively raise the successful puncture rate.

Key words: subclavian vein catheterization, misplaced catheters, magnet guide