Physicochemical characterization of hexetidine-impregnated endotracheal tube poly(vinyl chloride) and resistance to adherence of respiratory bacterial pathogens

Purpose. Ventilator-associated pneumonia is a frequent cause of mortality in intensive care patients. This study describes the physicochemical properties of hexetidine-impregnated poly(vinyl chloride) (PVC) endotracheal tube (ET) biomaterials and their resistance to microbial adherence (Staphylococcus aureus and Pseudomonas aeruginosa). Methods. PVC emulsion was cured in the presence of hexetidine (0-20% w/w) and was characterized in terms of drug release, surface properties (i.e., microrugosity/contact angle), mechanical (tensile) properties, and resistance to microbial adherence. Results. Under sink conditions, hexetidine release from PVC was diffusion-controlled. Increasing the concentration of hexetidine from 1% to 10% (w/w) (but not from 10% to 20% w/w) increased the subsequent rate of drug release. In general, increasing the concentration of hexetidine decreased both the tensile properties and hydrophobicity, yet increased PVC microrugosity. Following hexetidine release (21 days), the surface properties were similar to those of native PVC. The resistance of hexetidine-containing PVC (1% or 5%) to microbial adherence (following defined periods of drug release) was greater than that of native PVC and was constant over the examined period of hexetidine release. Conclusions. ET PVC containing 1% (w/w) hexetidine offered an appropriate balance between suitable physicochemical properties and resistance to microbial adherence. This may offer an approach with which to reduce the incidence of ventilator-associated pneumonia.