A microbiological comparison of a povidone-iodine lubricating gel and a control as catheter lubricants.

A randomized, controlled study tested the value of a povidone-iodine (PVP-I) lubricant ('Betadine' lubricating gel), in preventing microbial contamination of bladder urine during catheterization. Urine samples, for culture, were obtained by suprapubic aspiration both before passage, and after removal 15 min later, of a no. 16 Foley catheter coated with the test lubricant or with a control preparation ('K-Y' lubricating jelly). Each treatment group included 10 men and five women. Swab cultures of the anterior urethra, taken immediately before catheterization, demonstrated substantial urethral contamination. Thirteen test subjects and 15 controls qualified for the efficacy analysis and all 30 took part in the safety evaluation. Before catheterization, mean colony counts per 5 ml urine numbered 0.3 in the (PVP-I) treated group and 0.4 among controls. After catheter passage, the mean counts were respectively, 3.6 and 69.6 per 5 ml. Thus, catheters coated with PVP-I lubricating gel transported significantly fewer (P less than 0.03) viable contaminants to bladder urine than those covered with 'K-Y' jelly. The organisms most frequently identified in urethral swabs and pre-study midstream clean-catch specimens also predominated in post-catheterization urine, but their incidence was considerably lower among the PVP-I treated subjects than among controls. Lubricity, cohesiveness and adhesiveness were more satisfactory in the test group than in the control series. No adverse reactions occurred and both preparations, as well as the mechanical procedures, were well tolerated. The findings demonstrated the efficacy of the PVP-I lubricant in preventing transfer of viable urethral organisms to the bladder during catheterization.