The Mechanical Properties of Intact and Traumatized Epidural Catheters

• Published in: Anesthesia and analgesia Vol. 90; no. 2; p. 393
• Main Authors: Ateş, Yeşim, Yücesoy, Can Ali, Ünlü, M. Ağahan, Saygin, Birsen, Akkaş, Nuri
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD International Anesthesia Research Society 01.02.2000; Lippincott
• Subjects: Algorithms; Anesthesia; Anesthesia, Epidural - instrumentation; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Anesthesia: equipment, devices; Biological and medical sciences; Catheterization; Elasticity; Equipment Failure Analysis; Medical sciences; Needles; Nylons; Polyurethanes; Stress, Mechanical; Tensile Strength; Extradural; Regional anesthesia; Extradural administration; Catheter; Elasticity; Mechanical properties; Robustness; Hardness; In vitro; Physical properties; Comparative study; Technical equipment
• ISSN: 0003-2999; 1526-7598
• DOI: 10.1097/00000539-200002000-00029

Comparative data on the mechanical properties of epidural catheters used clinically are not available. We performed a controlled laboratory investigation to assess the mechanical performance of three different intact or traumatized catheter types (Polyurethane, clear nylon, and radiopaque nylon catheters, designed for 18-gauge Tuohy needles). We studied a control (intact) and two trauma groups (needle bevel and surgical blade). Catheters were loaded to their breaking points by using a Lloyd LS500 material testing machine (Lloyd, Southampton, UK). Maximal load and extension values before breakage were measured, and modulus of elasticity and toughness values were calculated. Intact polyurethane catheters did not break within the limits of the experimental study (extension up to 3 times the original length of a specimen). The toughness values obtained from polyurethane and clear nylon catheters were significantly higher than those for the radi- opaque catheters in intact specimens (P < 0.05). In the traumatized groups, polyurethane catheters had the highest toughness values (P < 0.05). Modulus of elasticity values were higher in both control and trauma groups of the radiopaque catheters when compared with the polyurethane and clear nylon catheters, which indicates a higher stiffness to elastic deformation (P < 0.05). In conclusion, polyurethane catheters are the most durable catheter type to tensile loading, either intact or traumatized. Mechanical properties can be used to predict complications related to the clinical use of these catheters. IMPLICATIONSUsing a computer-assisted material testing machine, we studied the mechanical properties of three different types of epidural catheters, either intact or traumatized, in a blinded, controlled study. This information may be vital to clinicians who implant epidural catheters by helping them choose a catheter that has the lowest probability of failure.