Knapp U, Sander J, Vieweg K
Dtsch Med Wochenschr. 1975 Jan 3;100(1):10-3. doi: 10.1055/s-0028-1106160.
After 'clean' operations, 121 Redon drains from 80 patients were cultured. 17.4% of Redon tips were contaminated, but microorganisms were found in only 7.4% of wound secretions aspirated from them before they were removed. Only Gram-positive cocci, most of them of questionable pathogenicity, were found. Although drains or wound secretions were found to be contaminated in 21 patients, clinical evidence of disturbed healing occurred in only two patients. The presence of microorganisms provided no pointer to later healing difficulties. Culturing Redon tips is, therefore not a reliable method for early recognition of wound infections. Antibiotics should not be used merely on evidence of bacterial contamination of Redon tips without any clinical signs of infection.