Definition of catheter jamming: A mechanical analysis of catheter fracture tension and fracture strain.

Background: Catheter jamming is an emerging and possibly underrated complication.

Objective: To find the criteria for determining if the catheter cannot be removed through the mechanical analysis of fracture tension and fracture strain (εf) of Peripheral Inserted Central Catheters (PICC).

Method: We removed 30 pieces of PICC catheters from patients and recorded the indwelling time. Those with an indwelling time shorter than 12 weeks belonged to the short-term group. Those with an indwelling time longer than 12 weeks belonged to the long-term group. The first half of the same catheter is section A, and the second half is section B. The fraction tension and fracture strain of the catheter were measured, and statistical analysis was conducted.

Results: The fracture tension of catheter in sections A and B were 5.8917 ± 1.0095 and 6.0670 ± 0.8066 Newtons respectively (p= 0.393) and the fracture strain of catheter in sections A and B were 6.0611 ± 1.0810 and 6.2543 ± 0.7187 Newtons respectively (p= 0.343). The fracture tension of catheter in short-term and long-term group were 6.0696 ± 0.9414 and 5.9192 ± 0.8972 Newtons respectively (p= 0.535) and the fracture strain of catheter in short-term and long-term group were 6.0067 ± 0.7227 and 6.2584 ± 1.0212 respectively (p= 0.301).

Conclusion: It is objective and consistent to take the catheter fracture tension as the standard. This standard would be able to accurately define the concept of catheter failure and reduce the risk of catheter fracture and the misdiagnosis of catheter failure. The catheter fracture tension and fracture strain was not affected by the catheter indwelling time. It is recommended to set the tensile force as 5 Newtons and carry it out at a speed of 100 mm/min for the catheter drawing of the PICC single-lumen silicone catheter (4.0F) from Budd Company.