title: The mechanical properties of continuous spinal small-bore catheters.
abstract: Continuous spinal anesthesia (CSA) has a nearly 100-yr history. In situations of difficult removal of a CSA small-bore catheter, mechanical properties of the different catheters might be important, because breakage could occur. We compared 5 different CSA small-bore catheters, 22- to 28-gauge from 3 manufacturers, for tensile strength, tensile stress, distension, and yield strength. Maximal tensile strength is the force applied before breakage of the catheter. The material characteristics of different CSA small-bore catheters for maximal tensile strength were: 22-gauge = 29.56 +/- 1.56 (mean +/- sd) Newton (N), 24-gauge = 16.77 +/- 1.61 N, 25-gauge = 9.20 +/- 0.48 N, 27-gauge = 4.61 +/- 0.25 N, 28-gauge = 5.07 +/- 0.59 N at room temperature. A strong correlation between maximal tensile strength and the outer diameter (r = 0.957, P < 0.001) and maximal tensile strength and the wall thickness (r = 0.9, P < 0.001) was observed. Although extrapolation from experimental studies to clinical routine should be made with care, our data suggest that catheters with higher-strength characteristics may reduce the risk of catheter breakage in patients, although clinical correlations are lacking.
authors.affiliation: *Department of General Anesthesiology and Intensive Care-B, Vienna Medical University, General Hospital Vienna, Vienna, Austria; and †Charité-University Medicine Berlin, Campus Benjamin Franklin, Department for Medical Computer Science, Biometry and Epidemiology, Berlin, Germany.
authors.forename: Engelbert
authors.initials: E
authors.lastname: Deusch
authors.forename: Justus
authors.initials: J
authors.lastname: Benrath
authors.forename: Lukas
authors.initials: L
authors.lastname: Weigl
authors.forename: Konrad
authors.initials: K
authors.lastname: Neumann
authors.forename: Sibylle A
authors.initials: SA
authors.lastname: Kozek-Langenecker
mesh_terms: D000775:Anesthesia, Spinal / Q000295:instrumentation*; D002404:Catheterization; D004548:Elasticity; D004868:Equipment Failure; D013718:Tensile Strength