Povidone Iodine and Skin Disinfection before Initiation of Epidural Anesthesia

Background: Povidone iodine (PI) solution is used commonly for skin disinfection before epidural and spinal anesthesia. Although there have been reports indicating the presence of microbial contaminants in PI solution, none have evaluated the prevalence of PI contamination. The aims of this study were to assess the frequency of bacterial contamination of previously opened bottles of PI solution and to compare the effectiveness of new and previously opened bottles of PI solution for skin disinfection.

Methods: Twenty previously opened and ten previously unopened multiple-use bottles of PI solution were evaluated for microbial contamination. In addition, final swabs and PI solution used for skin disinfection in 80 patients undergoing elective epidural analgesia were evaluated.

Results: The inside of the bottle cap or the PI solution from 40% of the multiple-use PI bottles in use were contaminated. There was no growth from any previously unused PI bottles. Povidone iodine from newly opened bottles provided more effective skin decontamination than did solution from previously opened bottles.     

Sterilisation of skin allograft with gamma irradiation

The primary surgical requirement of skin allografts within the UK is for cryopreserved viable allografts as these engraft to the wound bed and gain a vascular supply, thus providing true wound closure and a superior clinical performance. Consequently the only disinfection treatment the skin receives is exposure to an antibiotic cocktail. However, antibiotic treatment does not reliably decontaminate skin allografts and 22% of cryopreserved skin fails microbial acceptance criteria and cannot be used clinically. We describe here a study which was carried out to determine a means of saving and using the microbiologically failed skin. Four different treatment regimens were investigated; treatment with 20%, 50% and 85% glycerol followed by 25 kGy irradiation at -80 degrees C, and treatment with 85% glycerol at ambient (30-40 degrees C) temperature and irradiation. Following treatment, the grafts were evaluated for their histological structure, in vitro cytotoxicity and handling properties. The radioprotective effects of the different glycerol concentrations and temperatures on microorganisms were also determined. The data indicate that 25 kGy irradiation of deep-frozen skin in 20% glycerol sterilised the tissue without any histological, cytotoxicological or physical alterations compared to normal cryopreserved skin. In contrast, irradiation of all other glycerol concentrations elicited some cytotoxicity and/or histological effect. These non-viable grafts can be made available for surgical use when cryopreserved viable grafts are not available or required.     

Die Sterilisation von Instrumenten in Theorie und Praxis

Zusammenfassung Es wird dargelegt, da? Gartenerde, das allgemein übliche Testobjekt für Sterilisationsversuche, diesen Zweck nur ungenügend erfüllt und mit vielen Fehlerquellen behaftet ist. Die in ihr enthaltenen „nativen” Erdsporen sind deshalb widerstandsf?higer als Kultursporen der gleichen Art, weil die Erdk?rnchen ihnen einen weitgehenden mechanischen Schutz verleihen. Bei einer den praktischen Verh?ltnissen entsprechenden Versuchsanordnung werden die Sporen der Gartenerde durch Kochen in 1–2%iger Sodal?sung in l?ngstens 30 Minuten abget?tet. Dieses Verfahren kann unbedenklich für die Sterilisation von Instrumenten benutzt werden. Durch einen ganz geringen Zusatz von Formaldehyd (0,2%) wird die sterilisierende Wirkung noch verst?rkt, was in h?her gelegenen Orten mit entsprechend erniedrigter Siedetemperatur des Wassers von Vorteil sein kann.