In vitro bacteriological evaluation of the effectiveness of antimicrobial irrigating solutions.

Nineteen strains of pathogenic aerobic bacteria were exposed for fifteen seconds in vitro to varying concentrations of five antibiotics and of polyvinyl povidone iodine in saline solution. The presence of human plasma in the solution (30 per cent by volume) did not affect bacterial sensitivity to the antibiotics. Most of the bacteria were sensitive to the solutions during that brief exposure. Bacteria which were more sensitive by disc sensitivity tests were more sensitive to the solutions. Polyvinyl povidone iodine sterilized all cultures in concentrations as low as 25 per cent. It is proposed that the use of appropriate antimicrobial solutions as wound irrigants may reduce postoperative infection rates by killing bacteria which contaminate the surface of the wound during operation.