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Biomedical subjects

H Rüden

Publications and source records attributed to H Rüden.

At least 73 records · Page 4Linked to original sources
PubMed2001

[Reduction of nosocomial infections by public health quality management in surgical patients. 2: No reduction in low initial infection rate].

In the framework of a prospective controlled study in surgical and intensive care units of four study and four control hospitals it was tried to set up an infection control quality management concept for reduction of nosocomial infections in hospital D. With an incidence density of 5.4 nosocomial infections per 1,000 patient days the most favorable situation among the four study hospitals was found initially in this hospital. However, after a small decrease of infection rate during the first study year, no benefit of intervention was achieved in this hospital at the end of the study (6.4 nosocomial infections per 1,000 patient days). Possible explanations may be a very small potential for reduction at the beginning, a change of patient mix due to a new head of the department and the phenomenon of the "regression to the mean". Distinct improvements of the situation were achieved on the level of process quality. Meanwhile surveillance of nosocomial infections became an integral part of quality management in this hospital. The quality circle method was not well accepted for the longterm. But the concept of link nurses was introduced successfully.

Cross Infection↗
PubMed2001

Capability of air filters to retain airborne bacteria and molds in heating, ventilating and air-conditioning (HVAC) systems.

The capability of air filters (filterclass: F6, F7) to retain airborne outdoor microorganisms was examined in field experiments in two heating, ventilating and air conditioning (HVAC) systems. At the beginning of the 15-month investigation period, the first filter stages of both HVAC systems were equipped with new unused air filters. The number of airborne bacteria and molds before and behind the filters were determined simultaneously in 14 days-intervals using 6-stage Andersen cascade impactors. Under relatively dry (< 80% R. H.) and warm (> 12 degrees C) outdoor air conditions air filters led to a marked reduction of airborne microorganism concentrations (bacteria by approximately 70% and molds by > 80%). However, during long periods of high relative humidity (> 80% R. H.) a proliferation of bacteria on air filters with subsequent release into the filtered air occurred. These microorganisms were mainly smaller than 1.1 microns therefore being part of the respirable fraction. The results showed furthermore that one possibility to avoid microbial proliferation is to limit the relative humidity in the area of the air filters to 80% R. H. (mean of 3 days), e.g. by using preheaters in front of air filters in HVAC-systems.

Air Conditioning↗
PubMed2001

Converting incidence and prevalence data of nosocomial infections: results from eight hospitals.

OBJECTIVE: To investigate the use of the formula of Rhame and Sudderth for the interconversion of prevalence and incidence data on the frequency of nosocomial infections. DESIGN: Comparison of observed and calculated incidence data and prevalence data. SETTING: One 8-week incidence investigation in the surgical and intensive care units of eight medium-sized hospitals; three separate point-prevalence studies in the same units. RESULTS: The overall prevalence observed after the three prevalence studies in 2,169 patients was 6.8% (95% confidence interval [CI95], 5.7-8.0). In 2,882 discharged patients observed during the incidence study, the mean hospitalization was 9.8 days; patients with one or more nosocomial infection had a mean hospitalization time of 22.3 days and a mean interval of 8.2 days from admission to the first day of infection. Based on these data, the overall calculated incidence was 4.7%, whereas the observed incidence was 4.3% (CI95, 3.6-5.2). Vice versa, an overall prevalence of 6.2% was found when calculated from the observed incidence data. The incidence data calculated from prevalence data also were within the confidence interval of the incidences observed for urinary tract infections and surgical-site infections. (However, it was not possible to convert the data for two of the eight hospitals.) CONCLUSION: The approximate mathematical relationship between the prevalence and incidence data of nosocomial infection is confirmed by this study. However, although it is theoretically possible, we would not recommend the conversion of prevalence into incidence data or vice versa.

Cross Infection↗
PubMed2001

Surveillance of nosocomial infections in ICUs: is postdischarge surveillance indispensable?

OBJECTIVE: To determine how many infections are missed if the postdischarge surveillance (PDS) follow-up of intensive care unit (ICU) patients that is required by the National Nosocomial Infection Surveillance System method is not done. DESIGN: ICU patients were followed up and surveillance results with PDS (gold standard) and without PDS were compared. SETTING: Surgical or interdisciplinary ICUs in eight German acute-care hospitals. PATIENTS: All 1,857 patients within a 6-month period in the participating ICUs (a total of 9,129 ICU-patient-days). RESULTS: Without PDS, 45 urinary tract infections (UTIs) were diagnosed, compared with 53 with PDS; thus, 15% of the UTIs were missed if no postdischarge follow-up was performed. Three nosocomial pneumonias (4%) and one bloodstream infection (8%) also were missed if surveillance was carried out without PDS. A total of 198 nosocomial infections (NIs) were recorded with PDS, compared to 175 NIs without PDS. Approximately 12% of all ICU-associated NIs were missed if no follow-up was done. CONCLUSIONS: Since it is very time-consuming to follow patients after their transfer from the ICU, we do not perform a postdischarge follow-up of patients in the course of routine surveillance.

Cross Infection↗
PubMed2000

[Human granulocytic ehrlichiosis. New tick bite disease lies in wait also in German forests].

HGE is an uncommon zoonosis, transmitted to humans by ticks (Ixodes ricinus). Heavily exposed persons, such as foresters and forestry workers, are most at risk of infection. HGE usually runs an asymptomatic and self-limiting course. Symptoms include acute pyrexial illness, frequently accompanied by muscle pain, headache, nausea and vomiting. Treatment is with doxycycline/tetracycline or rifampicin. In a study in Hesse of 128 heavily exposed subjects, 19.5% had serum antibodies (IFA test) against HGE versus 4.4% in a control group. This difference is statistically significant. The prevalence of both symptoms and the seropositivity differ significantly between locations. HGE should be considered in the differential diagnosis of fever of unknown origin following tick bite exposure, at least in the North Hesse region.

Animals↗
PubMed2000

[Reasonable and unreasonable hygiene measures in anesthesia in the intensive care unit].

The objective of this review is to describe which hygiene measures are appropriate and necessary in anaesthesia and the ICU and which are not, whereby unnecessary hygiene measures are those which are not substantiated by scientific data. The most effective single infection control measure is still hand disinfection between patient contacts. Unnecessary measures include routine sampling of environmental surfaces, disinfecting the floor in the ICU, protective gowns for visitors, so called in-line filters in the infusion system etc. Ventilator tubes only need to be exchanged once a week, even when no HMEs are used.

Anesthesia↗
PubMed2000

[Establishment of a national database for ICU-associated infections. First results from the "Krankenhaus-Infections-Surveillance-System" (KISS)].

OBJECTIVES: To establish a surveillance system as an element of internal quality management, participating intensive care units (ICUs) report their ICU-associated infection surveillance data for aggregation into a national database. METHODS: In order to provide data on ICU-associated infections, a nosocomial surveillance system in German intensive care units (Krankenhaus-Infections-Surveillance-System (KISS)) started in 1997. The method of data collection is based on the (adult) ICU surveillance component from the National Nosocomial Infections Surveillance (NNIS)-System. Until now 113 German ICUs (most of them medical/surgical ICUs) were included in this system. We continuously collected and calculated the data from site-specific infections (device-associated pneumonias, blood stream infections and urinary tract infections). RESULTS: There are now a total of 393,177 patient-days (100,015 patients) among them 176,415 ventilator-days, 295,221 central line-days and 316,799 urinary catheter-days in the data base. The data analysis showed the following device-associated infection rates: 11.2 pneumonias/1000 ventilator-days, 1.8 primary bloodstream infections/1000 central line-days and 4.0 urinary tract infections/1000 urinary catheter-days. CONCLUSION: The project has reached high interest in Germany and animated more ICUs to take part or to apply the same method in order to use the reference data for comparison.

Cross Infection↗
PubMed2000

[Evidence-based recommendations for perioperative antibiotic prophylaxis].

The aim of perioperative antibiotic prophylaxis (PAP) is to reduce postoperative complications. In 1994 specialist American companies developed a PAP quality standard, whereby individual recommendations were divided into categories according to the degree of evidence. These recommendations have been tabulated and supplemented with the results of new, randomized, controlled studies.

Antibiotic Prophylaxis↗
PubMed2000

Repeated prevalence investigations on nosocomial infections for continuous surveillance.

In order to obtain an overview for the planning of further infection control activities, nine repeated prevalence studies were performed at monthly intervals. These occurred in the surgical units of eight medium-sized German hospitals. A total of 4984 surgical patients were investigated, the number of patients observed in each hospital varied from 365 to 913 patients, an average of 69.2 patients per prevalence study per hospital. A total of 212 nosocomial infections were found, the majority being surgical site (43.9%) and urinary tract infection (33.0%). The overall prevalence rate was 4.0%. More than four repeated investigations had only a minor influence on the 95% confidence intervals, and a follow-up of late microbiological reports increased the prevalence rate by only 7.5%. However, it was very useful to record the presence of urinary catheters on the prevalence day and also the preceding days; for instance, a device-associated prevalence of 7.8 urinary tract infections per 100 patients with urinary catheters was found on the day of investigation. In order to evaluate the situation in one's own surgical department by prevalence studies and for reasons of cost-effectiveness, the workload can be limited to four repeated studies in most hospitals. A further follow-up of later microbiological reports is not recommended, and it seems useful to concentrate on patients with indwelling devices.

Cross Infection↗
PubMed2000

Can quality circles improve hospital-acquired infection control?

It is a fundamental principle of continuous quality improvement (CQI) that processes should be the objects of quality improvement. The objective of this study was to improve process quality concerning the prevention of hospital-acquired infections in surgical departments and intensive care units by a continuous quality improvement (CQI) approach based mainly on quality circles. This approach was evaluated in a prospective controlled intervention study in medium-size acute care hospitals (four intervention and four control hospitals). During two intervention periods (each 10 months) four external physicians with training in hospital epidemiology and infection control introduced and supervised quality circles in the intervention hospitals. Process quality was assessed by interviewing senior staff members before the first and after the second intervention period using standardized questionnaires. The gold standard process quality was defined on the basis of the CDC/HICPAC-guidelines for the prevention of hospital-acquired infections. Most of the evaluated aspects of process quality belonged to the HICPAC-categories IA and IB respectively, the CDC category I. Fifty quality circle sessions were performed in the four intervention hospitals of which 28 were dealing directly with key subjects in infection control. In the intervention hospitals, 19.8% of evaluated aspects of process quality which concerned the prevention of hospital-acquired infections were improved compared to only 6.9% in the control hospitals (P<0.05). Sixty-six point seven percent of positive changes in process quality were initiated by the results of the quality circles. Our study demonstrates that a CQI approach based on infection control quality circles can lead to a substantial improvement of process quality regarding the prevention of hospital-acquired infections.

Cross Infection↗
PubMed2000

An outbreak of pyodermas among neonates caused by ultrasound gel contaminated with methicillin-susceptible Staphylococcus aureus.

OBJECTIVE: To investigate an outbreak of methicillin-susceptible Staphylococcus aureus (MSSA) infections in a neonatal clinic. DESIGN: Prospective chart review, environmental sampling, and genotyping by two independent methods: pulsed-field gel electrophoresis (PFGE) and randomly amplified polymorphic DNA polymerase chain reaction (RAPD-PCR). A case-control study was performed with 31 controls from the same clinic. SETTING: A German 1,350-bed tertiary-care teaching university hospital. RESULTS: There was a significant increase in the incidence of pyodermas with MSSA; 10 neonates in good physical condition with no infection immediately after birth developed pyodermas. A shared spatula and ultrasound gel were the only identified infection sources. The gel contained MSSA and was used for hip joint sonographies in all neonates. PFGE and RAPD-PCR patterns from 6 neonates and from the gel were indistinguishable and thus genetically related clones. The case-control study revealed no significant risk factor with the exception of cesarean section (P=.006). The attack rate by days of hip-joint sonography between April 15 and April 27, 1994, was 11.8% to 40%. CONCLUSIONS: Inappropriate hygienic measures in connection with lubricants during routine ultrasound scanning may lead to nosocomial S. aureus infections of the skin. To our knowledge this source of S. aureus infections has not previously been described.

Case-Control Studies↗
PubMed2000

Identifying outliers of antibiotic usage in prevalence studies on nosocomial infections.

OBJECTIVE: To investigate whether the correlation between patients' antibiotic treatment (yes/no) and patients' infections (yes/no) in each hospital department, described by Pearson's correlation coefficient (p) for binary data as a measure for adequate use of antibiotics, is an appropriate quality indicator. DESIGN: Comparison of the results of repeated prevalence studies in different hospitals with the data of a national prevalence study, comparing the hospital (p) and reference (pNIDEP[Nosokomiale Infektionen in Deutschland: Erfassung und Pravention]) correlation coefficients for "use of antibiotics/ presence of infections." SETTING: The data of 5,377 surgical patients were separated from the total data of a national prevalence study in 72 representative hospitals to create a reference correlation coefficient (rhoNIDEP) with a reference range. Nine additional prevalence studies, involving a total of 4,984 patients, were repeatedly performed in the surgical departments of 8 other hospitals during a 12-month period, whereby the correlation coefficients rho(n) for every prevalence investigation were determined. RESULTS: In the national prevalence study, 15.3% of the surgical patients received antibiotics on the study day. Surgical patients had a 3.8% prevalence of nosocomial infections and a 7.0% prevalence of community-acquired infections. Pearson's correlation coefficient rhoNIDEP for correlation between patients' binary data use of antibiotics and presence of infection was 0.62. To compare the correlation coefficient of each department with the appropriate reference range, the coefficients of the single departments were plotted against the number of patients; in these plots, three lines indicated the value rhoNIDEP and the upper and lower reference ranges, depending on the number of patients. Seven of eight surgical departments investigated during the repeated prevalence studies were found to be within the reference range, near the reference value, in the majority of prevalence studies; only one of the departments was identified as an outlier as regards antibiotic use. CONCLUSION: The correlation between patients' antibiotic treatment (yes/no) and patients' infections (yes/no) in hospitals or departments, as described by Pearson's correlation coefficient p for binary data with a definitive reference range depending on the number of patients, is useful for quality management in identifying the overall necessity for evaluating the indications for antibiotic use in one's own hospital.

Anti-Bacterial Agents↗
PubMed2000

How to survey nosocomial infections.

Many surveillance methods for nosocomial infections (NIs) have been put forward in the literature, and all have their advantages and disadvantages. Different surveillance methods are useful, depending on whether the objective of surveillance is only to increase sensitivity to infection control problems and to identify areas with possible infection control problems; to confirm a possible infection control problem through comparison with other units or departments; or to use surveillance data for identifying the sources of infections. Furthermore, time effectiveness is a major point in selecting the most appropriate method, particularly the method for case identification. In units or departments with a high level of NI, even highly time-consuming surveillance methods may be ultimately time-effective; in units or departments with a lower level of NI, the time-effectiveness depends on the time necessary for case identification. Close liaison with staff in the units is a sine qua non for the success of all surveillance activities.

Cross Infection↗