Efficacy of sodium hypochlorite against multidrug-resistant Gram-negative bacteria.

BACKGROUND: Increased antimicrobial resistance has been observed among many bacteria leading to treatment failures in human and veterinary medicine. Disinfection is a prerequisite for infection control and prevention in healthcare settings. Chlorine compounds are cost-effective and accessible worldwide. AIM: To determine the efficacy of sodium hypochlorite (NaOCl) against multidrug-resistant Gram-negative bacteria (MDR-GNB). METHODS: Minimum inhibitory concentrations (MICs) were determined using broth macro-dilution. Bactericidal efficacy was measured by qualitative and quantitative suspension tests followed by practical tests without mechanical action on stainless steel carriers. The guidelines of the German Association for Applied Hygiene were followed. FINDINGS: Results varied remarkably depending on the method. MICs were 0.1% or 0.2% NaOCl. Qualitative suspension tests revealed up to 500-fold lower bactericidal concentrations. Pseudomonas aeruginosa (P = 0.0025) was significantly less susceptible in these tests whereas quantitative suspension tests revealed no significant differences between strains (P > 0.05). Practical tests determined bactericidal concentrations of 0.8-0.32% NaOCl at 1 min of contact and even lower concentrations for longer contact times. At 1 min, five Klebsiella were significantly less susceptible (P = 0.0124), whereas the lower susceptibility of P. aeruginosa was not confirmed. Organic load inhibited bactericidal activity significantly, whereas contact time had a marginal effect. Differing test results underline that MIC determination and qualitative suspension tests may be insufficient approaches to evaluate bacterial susceptibility or resistance. CONCLUSION: NaOCl efficiently reduced Pseudomonas aeruginosa, Acinetobacter spp., and Klebsiella spp., most notably in the absence of organic matter. Strain- and species-specific differences in susceptibility were noticed, but in general MDR-GNB revealed no higher tolerance to NaOCl.

Approaches to reliability in a clinical simulation study.

Discusses the reliability of measurements made by 48 raters who used the Problem Dysfunction Rating Scale (PDRS) under simulated routine clinical record-keeping conditions. Ten- to 15-minute videotape interviews of two simulated patients with predefined problems were shown to a multidisciplinary psychiatric hospital staff of varying educational background and clinical experience. These raters were given only brief instructions and no training in the use of the PDRS. Statistical analysis included application of the usual, traditional test and retest variation studies and used variance components and comparison to random rating models. A random contrast of rater agreement was found to index most realistically reliability in instances such as this, in which a large number of raters rate a small number of items. There was greater intrarater consistency than interrater agreement, and it was concluded that when reasonably adequate information was available the degree of dysfunction due to patients' problems could be rated on the PDRS with a useful degree of consistency by untrained raters.

Improving patient care through measurement: goal importance and achievement scaling.

Sophisticated treatment record keeping requires something more than a focus on problems. An emphasis on positive aspects of treatment, i.e., on goals may be more appropriate for certain patients or for certain types of treatment or at specific stages of an illness. Unfortunately, currently available methods of quantifying goal importance and achievement are not entirely satisfactory for general everday use. GIA is proposed as a simple procedure for quantifying judgments of the importance of a treatment goal, of the extent to which that goal is achieved and of determining the social value of what treatment has accomplished. GIA ratings have considerable potential for improving patient care through measurement.