Further experience with mercresin

T HE importance of the normaI bacteriaI Aora of the patient’s skin as a possible means of wound infection has been emphasized by many workers.’ As a result, the bactericida1 efficiency of the various germicides used in preoperative skin disinfection has been extensively studied.2,3,4,5,6,7,a,3 The Iaboratory evaIuation tests of these germicides have been standardized by the United States Food and Drug Administration,rO but the cIinica1 evahration has offered considerabIe diffrcuIty. The conditions of individua1 resistance, immunity, differences in kinds and virulence of the organisms, the reIative steriIity of the air in the operating room,‘1 the type and extent of the operation, and the surgical methods employed are variable factors which make definite conchrsions as to the reIative merits of one germicide compared to another very diffrcuIt. In some investigations the cIinica1 evaIuations of the various germicides have deaIt with artificia1 conditions such as in anima1 skin disinfection tests, the appIication of various Iaboratory cultures of bacteria to the surface of the skin, the painting of a very smaI1 area of skin under conditions not simiIar to those encountered in the operating rooms, and studies which take into consideration onIy the superficia1 contaminants of the skin. In order to determine the bactericida1 efficiency of severa germicides under conditions of use in the operating rooms of the University HospitaI, a series of studies were carried out. The foIIowing questions seemed to be of practica1 importance: I. Is the skin of the operative area contaminated when the patient is brought into the operating room? 2. Can the skin of the operative area be steriIized by a germicide preparation as empIoyed in the operating room? 3. Does the germicide penetrate the skin and steriIize the deeper layers? 4. Does the skin remain steriIe throughout the operation? 5. Is there a difference in the bactericida1 efficiency of the various germicida1 preparations studied? One hundred and seventy-three operative cases were selected for study. These incIuded herniorrhaphies, appendectomies, cholecystectomies, gastric resections, etc. Because most of these cases were compIicated (the hernias often were biIatera1 or required fascia1 sutures; the patients with biliary tract disease needed exploration of the common duct), the average duration of the operation was one and a haIf hours. The germicides studied for skin preparation were: (I) tincture of mercresin I : I000 (ortho-hydroxyphenylmercuric chIoride and a synthetic creso1); (2) tincture of merthioIate I : IOOO (sodium ethyImercurithiosaIicyIate); (3) tincture of iodine 2 per cent U.S.P. foIIowed by 50 per cent propanol.