Polyurethane central venous catheters, hydrochloric acid and 70% ethanol: a safety evaluation

Three groups of polyurethane central venous catheters (CVC) were infused daily for twenty days with 0.1 normal hydrochloric acid, 70% ethanol and normal saline (control) respectively to look for any changes in microscopic structural integrity. A 1 cm segment was cut from the distal end of each CVC daily. All sections were examined in a scanning electron microscope, looking for evidence either of damage to the lumen surface or of wall thinning. No significant damage to the lumen surfaces was observed with either treatment. Sporadic fine surface-pitting appeared late in the study without any clear temporal or treatment-related pattern. The mean CVC wall thickness did not change significantly over the study period (P = 0.15). Qualitative softening of ethanol treated catheters was observed, and this finding limits the recommendations for the use of ethanol. 0.1N HCl does not compromise the structural safety of the catheters, and its use should be considered when polyurethane CVC. become occluded.