To Örebro University

Background: To decrease contamination of needleless catheter hubs, caps or port protectors impregnated with isopropanol (IPA) have been developed and shown to be superior to other disinfection methods. The safety of the caps has been questioned, as they can be associated with alcohol leakage across the hub membrane.

Objectives: We evaluated the use of IPA caps and the scrub-the-hub method from the safety standpoint of possible alcohol leakage across the hub membrane.

Methods: Circuits imitating an intravenous line were constructed. Circuits with an IPA cap were flushed with sodium chloride after the hub had been exposed to the cap for 1 hour, 24 hours, and 7 days. At the end of each period the fluid was collected and amounts of IPA in it were measured, using gas chromatography. Scrub circuits without IPA caps were also tested and ethanol from these was measured using the same method.

Results: In this in vitro study, IPA was detected in all samples from cap circuits, and ethanol was detected from all scrub circuits. Leakage increased over time in IPA circuits. After 24 hours and 7 days of exposure, the first injection resulted in higher amounts of IPA; thereafter, the levels decreased. The amounts of ethanol measured from the scrub circuits were low.

Conclusions: IPA caps can cause leakage of alcohol across the hub membrane. Leakage increased over time, and a 30 sec drying time was not sufficient to solve the problem. Scrub-the-hub seems safe to use with regard to alcohol leakage.