A standardized test to assess the impact of different organic challenges on the antimicrobial activity of antiseptics.

This paper presents a suggestion for determining the antimicrobial efficacy of antiseptics in a phase 2/step 1 assay. Emphasis is placed on specific organic challenges to evaluate the efficacy of antiseptics used to rinse the oral cavity, mucous membranes, or wounds for either prophylactic or therapeutic reasons. Basic data are given concerning ready-to-use products based on Poly(1-vinyl-2-pyrrolidone-)iodine-complex (PVP-iodine), chlorhexidine, octenidine, or cetylpyridinium chloride. Hydrogen peroxide (3.0%) was included to assess a product with known limited efficacy only. Using Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Enterococcus faecium, and Candida albicans, a 10(5)-fold reduction can be achieved in 10 min without interfering substances. In the presence of 10% albumin, 10% sheep blood, or 1% mucin, a 10(3)-fold reduction is yielded using products based on PVP-iodine, octenidine, or chlorhexidine. The combination of 4.5% albumin, 4.5% sheep blood, and 1% mucin was the most difficult organic challenge and only the products based on PVP-iodine, octenidine, or chlorhexidine remained active. The cetylpyridinium-based product and hydrogen peroxide were less effective. Based on these data, a proposal for a phase 2/step 1 assay for antiseptics is presented to promote the standardization efforts.

The higher disinfectant resistance of nosocomial isolates of Klebsiella oxytoca: how reliable are indicator organisms in disinfectant testing?

The Children's Clinic in Giessen, Germany recently reported several severe infections with Klebsiella oxytoca resulting in deaths of two neonates. The putative source of the infections was a contaminated infusion solution. The resistance to disinfectant of the K. oxytoca isolates was investigated in three independent laboratories and was indeed found to be significantly increased. Comparative tests with standard strains of K. oxytoca and other recommended bacterial surrogates showed the disinfection procedures used were fully effective. The higher resistance of the nosocomial isolates may have developed due to improper handling and storage of the cleaning utensils. This report describes the events and draws conclusions concerning the use of disinfectants, the treatment of cleaning utensils, the reliability of procedures for testing disinfectants, and suggests additional measures.

The surgical gowns and drapes of tomorrow. Specifying material performance and test methods.

A mandatory European standard is being developed to establish basic requirements and test methods for disposable and reusable materials used for surgical gowns and drapes. Once this standard has been adopted, the continued use of cotton textiles and conventional cotton-polyester-mixed textiles will become questionable. This article outlines the proposed requirements and looks at alternative methods that use liquid-repellent micro-filament textiles or liquid-proof textile laminates.

Surgical gowns and drapes into the 21st century.

According to the MDD (Medical Devices Directive) 93/42/EEC of 13 June 1993, medical products including gowns and drapes must provide a high level of protection for patients, users and others. The European Commission CEN/TC 205/WG 14, under the leadership of its convenor, Professor Werner, is developing a mandatory European standard on the basic requirements and test methods for disposable and reusable materials for protection of patients, surgical personnel, and operating room facilities i.e. gowns and drapes. This European standard is intended to clarify the situation with respect to products and their properties, defining basic requirements, for users and manufacturers of medical products. Future use of standard cotton textiles and conventional cotton-polyester mixed textiles is uncertain as they may not meet the requirements of the new standard, i.e. resistance to penetration by microbiological microorganisms, liquids and particle release. However, there are innovative reusable barrier surgical drapes and gowns which meet the basic requirements of the standard made from liquid repellent micro-filament materials, material laminates and perhaps some specific cotton polyester materials which have been chemically modified. In the new standard based on CEN/TC 205/WG 14, quality assurance for reprocessing of surgical gowns and drapes is critical. The manufacturer/distributor must use validated processes to prove that the requirements of this European Standard are met. Quality Assurance Systems will be required to give proof of decontamination, disinfection and sterilisation. Specified processes are to be used to maintain the properties of the materials throughout reprocessing. It is the responsibility of the hospital to assure optimal protection of patients and users. In case of a lawsuit, this could lead to the burden of proof being shifted to the hospital, with related risk of liability because it is always assumed that the work is being done according to the 'state of the art'. Difficult situations arise when it must be proved that one has acted equivalent to or better than the standard procedures and that no mistakes are made. Because of this risk of liability alone, the question of what surgical materials are used in the future should be considered very carefully.

Influence of drape permeability on wound contamination during mastectomy.

Sixty-one patients undergoing mastectomy at three hospitals were randomly allocated to receive one of three types of drape: permeable linen sealed to the skin with self-adhesive nonwoven tape, and impermeable nonwoven with self-adhesive edges. Bacteriological contamination was assessed both in the wound and in the wound surroundings. The air counts at the centres differed but were generally low, mean approximately 10(1) colony-forming units (CFU)/m3 but higher at the beginning of the operation. Patients whose skin counts were high before disinfection had the highest skin counts after disinfection and operation and gave the highest counts on the gloves of the surgeon. The use of impermeable drapes instead of permeable linen drapes resulted in significantly fewer bacteria in the operative field (393 CFU/50 cm2 compared with 664, p less than 0.002) and also in the wound itself (12 compared with 164 CFU/sample, p less than 0.01). As a result of correlations between counts, we are also able to show how bacteria transfer from the patient's skin to the surgical wound.

[The value of preventive measures against legionellosis]. / Stellenwert der Massnahmen zur Legionellose-Prophylaxe.

The important dates from legionellosis research and relations from an epidemiological point of view are mentioned to estimate infectious risk and infectious sources. The ways of infection are mostly unknown. Proposals for sanitation of water-technical plant must be judged cautiously. Primarily the insertion of water into man must be prevented, especially into patients. Several possibilities of such insertions in clinical and private areas are mentioned.

[Complications and risks of suction drainage]. / Komplikationen und Risiken der Unterdruckdrainage.

After the introduction of Redon high-vacuum drainage, a considerable decrease in post-operative haematomas has been noted. But some of the complications could not be prevented by using the Redon system. They were in fact the result of it. The Redon system cannot be classified as a "closed" wound drainage. During bottle replacement, the system must be disconnected. An effective closed system must remain absolutely tight from application to removal of the drain so no possibility exists of contamination infection from the outside. After introduction of a continuously absolutely closed system in a prospective study with 3 different systems the influence after hip joint arthroplasty operations on wound healing was investigated. The wounds were drained with the Redon high-vacuum system or the newly developed, permanently closed drainage system with maximum obtainable low pressure of 80% vacuum and 50% vacuum. Here the maximum obtainable vacuum builds up slowly in relation to the accumulated amount of wound fluids. The loss of low pressure in Redon systems differs between the drains. In the intra-articular drains the mixture of air and blood results in a linear decrease and follows not a hyperbola like in subcutaneous drains. Because of the high suction at the beginning of the Redon drainage necrotic muscle cells adhere to the outside of the drain openings and clogs them up mechanically. The stronger the suction effect on the tissue, the more fatty live cells and small vessels enter the lumen of the drain in the Redon system and 80% vacuum. This mechanisms result in bleeding from the drain canal after removal of the drain and "secondary" haematomas. In the absolutely continuously closed system with maximum obtainable low pressure of 50% vacuum increased suction, lowered bleeding after removal of the drain and best healing results were observed. The 9.8% Cfu occurrence on Redon drains after removal found in the study is within the lower average figures given in literature while the 0.9% figure with both closed systems was never reached before.

[Complications of Redon drainage following hip joint replacement operations--an analysis of the causes]. / Komplikationen der Redon-Drainage nach Hüftgelenksersatzoperationen--eine Analyse der Ursachen.

After the introduction of Redon high-vacuum drainage, a considerable decrease in post-operative haematomas has been noted. But some of the complications could not be prevented by using the Redon system. They were in fact the result of it. The Redon system cannot be classified as a "closed" wound drainage. During bottle replacement, the system must be disconnected. An effective closed system must remain absolutely tight from application to removal of the drain so no possibility exists of contamination/infection from the outside. After introduction of a continuously absolutely closed system in a prospective study with three different systems the influence after hip joint arthroplasty operations on wound healing was investigated. The wounds were drained with the Redon high-vacuum system or the newly developed, permanently closed drainage system with maximum obtainable low pressure of 80% vacuum and 50% vacuum. Here the maximum obtainable vacuum builds up slowly in relation to the accumulated amount of wound fluids. The loss of low pressure in Redon systems differs between the drains. In the intra-articular drains the mixture of air and blood results in a linear decrease and follows not a hyperbola like in subcutaneous drains. Because of the high suction at the beginning of the Redon drainage necrotic muscle cells adhere to the outside of the drain openings and clogs them up mechanically. The stronger the suction effect on the tissue, the more fatty live cells and small vessels enter the lumen of the drain in the Redon system and 80% vacuum. This mechanisms result in bleeding from the drain canal after removal of the drain and "secondary" haematomas.(ABSTRACT TRUNCATED AT 250 WORDS)

[Reuse of angiography catheters. Results and discussion of the present state of knowledge]. / Die Wiederaufbereitung von Angiographie-Kathetern. Ergebnisse und Diskussion des derzeitigen Wissensstandes.

The re-use of angiographic catheters after cleansing and sterilization with ethylene oxide has received increasing attention, primarily because of cost considerations. However, there are various risks in this common practice, mainly because the principles of maintenance are neglected. Experimental findings on cleansing, sterilization, and mechanical safety are discussed, leading to the conclusion that re-use of disposable catheters is possible only under certain circumstances.