[Infection control in the operating room: preventive measures and isolation precautions in cases of multidrug resistant pathogens]. / Infektionskontrolle im OP: Präventions- und Isolierungsmaßnahmen bei multiresistenten Erregern.

BACKGROUND: Providing surgical treatment for patients colonised or infected with multidrug resistant organisms (MDROs) is daily routine in German hospitals. However, there is uncertainty about the application of adequate infection control measures in the OR. One of the reasons is that specific guidelines are not available. MATERIAL AND METHODS: We evaluated current practice in surgical departments of selected German university medical centres using a questionnaire. In addition, centres were asked to provide in-house standard operating procedures (SOP), if available. RESULTS: Nineteen questionnaires from 19 departments within 4 centres and 5 in-house SOPs were ana-lysed. The results showed a broad spectrum of applied infection control measures. Wide variations existed both within centres and within departments of the same centre regardless of existing in-house standards. CONCLUSIONS: Guidelines addressing perioperative infection control measures for patients harbouring MDROs should be developed with a focus on practicability to reduce both transmission of MDROs and unreasonable measures. Implementation of existing SOPs can be a target for optimisation.

Correlations between bed occupancy rates and Clostridium difficile infections: a time-series analysis.

A time-series analysis was performed to identify the impact of bed occupancy rates and length of hospital stay on the incidence of Clostridium difficile infections (CDI). Between January 2003 and July 2008, a mean incidence of 0·5 CDI cases/1000 patient days was recorded. Application of a multivariate model (R2=0·50) showed that bed occupancy rates on general wards (P<0·01) and length of stay in intensive care units (ICUs) (P<0·01) influenced the incidence of CDI. Overcrowding on general wards and long periods in ICUs were identified as being positively associated with the incidence of CDI.

[Effectiveness and risks of isolation precautions in patients with MRSA and other multidrug-resistant bacteria]. / Patienten mit multiresistenten Erregern: Wirksamkeit und Risiko von Isolierungsmassnahmen bei "MRSA & Co."

The transmission of multidrug-resistant organisms (MRSA, VRE and ESBL producing bacteria) occurs predominantly if health-care workers are not compliant with hand hygiene procedures. The impact of single-room isolation in transmission prevention is often overestimated. As long as hand disinfection is not performed before and after patient contact and gloves are not removed, a single room will not prevent transmission by -itself. Understaffing is additionally worsening the situation. There is no consistent evidence sup-port-ing strict single-room isolation even though data show supportive tendencies. Social isolation is one of the risks that should be considered as well as the economic impact of using shared rooms as a single room. Up-to-date, evidence-based standard operating procedures and individual infection control recommendations should take these considerations into account. In general, contact precautions including isolation in a single room are performed in MRSA and VRE-positive patients. If a single room cannot be provided in a given case (a common problem in intensive care units), contact precautions can be performed in a shared room as an alternative. The problem of establishing an optimal compliance with standard precautions (especially hand hygiene) throughout all professional groups should be addressed. Additional precautions, including single-room isolation, should be implemented critically if indicated.

[Transmission of multidrug-resistant bacteria in ambulatory settings]. / Ubertragung von Problemkeimen im ambulanten Bereich.

Multidrug-resistant organisms (MDROs) such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE) und extended-spectrum beta-lactamase (ESBL-) producing bacteria are an ever-expanding challenge regarding infection control and prevention strategies also in ambulatory healthcare settings. The most important transmission mode for MDROs is direct or indirect contact involving the hands of healthcare workers. Strict adherence to standard precautions (and especially adherence to alcoholic handrub use) is essential in prevention of cross-transmission. Additional measures contribute to the control of MDROs: These include flagging of patients' records, establishing standards of care for patients with MDROs, continuing education of staff, disclosure of information to other involved healthcare providers and guideline-based antibiotic treatment and prophylaxis. Optimised cooperation of ambulatory healthcare providers and hospitals regarding management and control of MDROs (networking) is a promising future option.

Skin disinfection with octenidine dihydrochloride for central venous catheter site care: a double-blind, randomized, controlled trial.

To compare the efficacy of two commercially available, alcohol-based antiseptic solutions for preparation and care of central venous catheter (CVC) insertion sites, with and without octenidine dihydrochloride, a double-blind, randomized, controlled trial was undertaken in the haematology units and in one surgical unit of two university hospitals. Adult patients with a non-tunnelled CVC were randomly assigned to two different skin disinfection regimens at the insertion site: 0.1% octenidine with 30% 1-propanol and 45% 2-propanol, and as control 74% ethanol with 10% 2-propanol. Endpoints were (i) skin colonization at the insertion site; (ii) positive culture from the catheter tip (> or = 15 CFU); and (iii) occurrence of CVC-associated bloodstream infection (defined according to criteria set by the CDC). Four hundred patients with inserted CVC were enrolled from May 2002 through April 2005. Both groups were similar in respect of patient characteristics and co-morbidities. Skin colonization at the CVC insertion site during the first 10 days was significantly reduced by octenidine treatment (relative difference octenidine vs. control: 0.21; 95%CI: 0.11-0.39, p <0.0001). Positive culture of the catheter tip was significantly less frequent in the octenidine group (7.9%) than in the control group (17.8%): OR = 0.39 (95%CI: 0.20-0.80, p 0.009). Patients treated with octenidine had a non-significant reduction in catheter-associated bloodstream infections (4.1% vs. 8.3%; OR = 0.44; 95%CI: 0.18-1.08, p 0.081). Side effects were similar in both groups. This randomized controlled trial supports the results of two observational studies demonstrating octenidine in alcoholic solution to be a better option than alcohol alone for the prevention of CVC-associated infections.

Correlates of venous catecholamine concentrations in patients with type 1 diabetes during a cold pressor test.

In some patients with type 1 diabetes, various physiologic reactions during a cold pressor test (CPT) are impaired. Whether this is caused by diabetic autonomic neuropathy, disturbed secretion of catecholamines, or disturbed blood glucose control is unknown. The authors, therefore, performed CPTs in patients with type 1 diabetes and in control subjects. They measured blood glucose concentrations, insulin concentrations, cardiac autonomic reflexes, and (before and after the CPT) venous catecholamine concentrations and analyzed correlations between these variables. Twenty-two patients with type 1 diabetes (17 men, 5 women; mean age +/- SD, 26.6 +/- 6.5 y; diabetes duration, 7.6 +/- 0.7 y; glycosylated hemoglobin concentration, 7.7 +/- 2.4%) and 35 control subjects with comparable age and gender distributions were studied. Venous catecholamines were measured before and at the end of a 5-minute CPT. In patients with diabetes, only noradrenaline concentrations increased during the CPT, whereas adrenaline concentrations that were already increased at rest did not change. Adrenaline concentrations correlated inversely with insulin concentrations. In control subjects, both adrenaline and noradrenaline increased significantly during the CPT. In both groups, the magnitude of the individual change in catecholamine concentrations was inversely correlated with the respective resting concentration. Changes in catecholamines, cardiovascular reflex tests, and blood glucose concentrations did not correlate with blood pressure changes. The authors conclude that, in patients with diabetes, resting adrenaline concentrations are related to insulin concentrations. Contrary to control subjects, in patients with diabetes, only noradrenaline increased during CPTs. In both groups, changes in catecholamine concentrations after the CPT were inversely related to the respective resting concentrations.

Type I hyperlipoproteinemia due to a novel loss of function mutation of lipoprotein lipase, Cys(239)-->Trp, associated with recurrent severe pancreatitis.

Lipoprotein lipase (LPL) is the major enzyme responsible for the hydrolysis of triglyceride-rich lipoproteins in plasma. The purpose of this study was to examine the molecular pathogenesis of type I hyperlipoproteinemia in a patient suffering from recurrent severe pancreatitis. Apolipoprotein (apo) CII concentration was normal as well as apo CII-activated LPL in an in vitro assay. In postheparin plasma neither LPL mass nor activity was detectable, whereas hepatic lipase activity was normal. Direct sequencing of all 10 exons of the LPL gene revealed that the patient was homozygous for a hitherto unknown mutation in exon 6, Cys(239)-->Trp. The mutation prevents the formation of the second disulfide bridge of LPL, which is an essential part of the lid covering the catalytic center. Consequently, misfolded LPL is rapidly degraded within the cells, causing the absence of LPL immunoreactive protein in the plasma of this patient. In conclusion, we have identified a novel loss of function mutation in the LPL gene (Cys(239)-->Trp) of a patient with type I hyperlipoproteinemia suffering from severe recurrent pancreatitis. After initiation of heparin therapy (10,000 U/day sc), the patient experienced no more episodes of pancreatitis, although heparin therapy did not affect serum triglyceride levels.

Analysis of volatile organic compounds in human urine by headspace gas chromatography-mass spectrometry with a multipurpose sampler.

A multipurpose sampler (Gerstel MPS), designed for liquid large volume, gaseous and headspace samples was used for the GC-MS analysis of organic volatiles in human urine. Headspace sampling with a volume-, temperature- and speed-controlled gas-tight syringe was combined with a temperature-controlled cold injection system (CIS) for cold trapping, enrichment and focusing of analytes. Regular 2-ml GC vials filled with 1 ml acidified urine were used as headspace sampling vials. A 100-vial autosampler tray was equipped with an additional temperature and heating time controlled "preheating station" for five vials. Profiles of organic volatiles in human urine were determined and 34 components identified. Trimethylamine (TMA) and 4-heptanone as two metabolites of medical interest were quantified. Calibration curves and intra assay imprecision for 4-heptanone concentrations in the range of 40 to 800 ng/ml showed a correlation coefficient of r = 0.9980 and a relative standard deviation (RSD) between 3.0 and 3.4%. Calibration curves and intra-assay imprecision for TMA concentrations in the range of medical interest from 0.5 to 20 micrograms/ml showed a correlation coefficient of r = 0.9968 and a RSD between 4.1 and 6.8%. The high practicability of the multipurpose sampler for both gaseous and liquid samples together with the here shown good reproducibility and sensitivity make this single CIS-GC-MS system very attractive for routine clinical use in metabolic profiling of organic volatiles (headspace) and non-volatiles (liquid).

Correlation of imaging techniques to histopathology in patients with diabetic foot syndrome and clinical suspicion of chronic osteomyelitis. The role of high-resolution ultrasound.

OBJECTIVE: To investigate the role of ultrasound in the diagnosis of osteomyelitis in the diabetic foot compared with magnetic resonance imaging (MRI), bone scintigraphy (BS), and plain film radiography (PFR). RESEARCH DESIGN AND METHODS: We investigated 19 consecutive diabetic patients (2 women, 17 men, age 60.7 +/- 9.8 years, BMI 27.0 +/- 3.8 kg/m2) with clinical suspicion of bone infection of the foot. A high-resolution ultrasound system (Esaote/Biosound, Munich) with a linear array transducer up to 13.0 MHz was used. The prospective and blinded results of each method were compared with histopathology as the reference method after metatarsal resection. RESULTS: In 14 of 19 patients, histopathology confirmed osteomyelitis. Ultrasound showed a sensitivity of 79% (PFR, 69%; BS, 83%; MRI, 100%), a specificity of 80% (PFR, 80%; BS, 75%; MRI, 75%), a positive predictive value of 92% (PFR, 90%; BS, 91%; MRI, 93%), and a negative predictive value of 57% (PFR, 50%; BS, 60%; MRI, 100%). CONCLUSIONS: Our data indicate that ultrasound might have a better diagnostic power for detecting chronic osteomyelitis in the diabetic foot than PFR and has similar sensitivity and specificity as BS. MRI is superior to the other three methods. We conclude that the use of ultrasound in the management of the diabetic foot is worthy of further investigation.

Evaluation of polarographic measurements of basal muscle oxygen tension in type I diabetic patients.

Microcirculatory changes occur early in insulin-dependent diabetes mellitus (IDDM) and are believed to be an early feature of late diabetic complications, leading to reduced oxygen pressure and hypoxia in the skin and other tissues. Whether muscle oxygen supply is also altered is unknown. Therefore, the authors analyzed polarographic measurements of muscle oxygen tension in 44 healthy type I diabetic patients (mean age 28 years; mean diabetes duration 7 years) and in 57 healthy controls, matched for age, sex, and body mass index, and the corresponding influencing factors. Two measurements were taken at rest 60 minutes apart in the anterior tibial muscle. Muscle oxygen tensions did not differ between IDDM patients and controls (23.0 +/- 8.6 vs 25.3 +/- 9.0 mmHg) and were reproducible on repeated measurements (25.3 +/- 9.7 vs 25.5 +/- 7.4 mmHg). Coefficients of variation were 13.5 +/- 10.8% in IDDM patients and 13.1 +/- 9.3% in controls. Compared with controls, in IDDM patients hemoglobin A1c (HbA1c) and blood glucose concentrations were elevated, and arterial oxygen pressure was significantly lower. Muscle oxygen tensions were positively correlated with blood glucose concentrations in IDDM patients (Rho=0.48, P=0.002) but not with HbA1c or with insulin concentrations. The authors conclude that the polarographic measurement of muscle oxygen tension is a reliable method with good reproducibility. Hypoxia in the anterior tibial muscle of type I diabetic patients can be excluded. In IDDM patients the level of muscle oxygen tension is correlated with the level of blood glucose concentration.

Interpretation of clinical trials for the treatment of diabetic neuropathy.

Since with currently available technical equipment normoglycemic metabolic control cannot be attained in diabetic patients to prevent diabetic neuropathy, in addition to optimizing metabolic control, drugs will be necessary for prophylaxis and treatment of diabetic neuropathy to reduce compromising symptoms, to prevent debilitating late sequelae and to reduce the prognostic impact. Long-term treatment requires optimal risk-benefit-cost ratios of drugs used. For the practicing physician, it may be difficult to judge from the literature whether proposed treatments are in fact beneficial when used in general practice. The following points should be kept in mind when drawing conclusions from the literature: 1) homogeneity of the neuropathy under discussion, 2) severity of the neuropathy, 3) metabolic control, 4) sufficient numbers of probands, 5) sufficient duration of treatment, 6) definition of treatment goals and the impact of surrogate variables, 7) reproducibility of outcome measures, 8) definition of successful treatment, 9) time-dependent changes in both treatment and placebo groups, 10) adequate statistical evaluation, 11) numerical presentation of treatment results, 12) generalization of trial results, 13) tolerable side effects, and 14) publication bias.

Pain intensity and blood pressure reactions during a cold pressor test in IDDM patients.

OBJECTIVE: To determine the contribution of altered pain perception to the impaired blood pressure reactions during a cold pressor test in diabetic patients. Reduced blood pressure increases have been observed in diabetic patients during a cold pressor test and have been attributed to an impaired efferent sympathetic function. RESEARCH DESIGN AND METHODS: We investigated pain intensities and blood pressure reactions simultaneously during a cold pressor test in 30 IDDM patients (diabetes duration 12 +/- 6 years, HbA1c 7.5 +/- 1.4%) and in 30 normal control subjects with comparable sex distribution, age, height, BMI, physical fitness, and smoking habits. RESULTS: Initial pain intensities and respective time courses did not differ between the two groups. The initial blood pressure response was significantly smaller in diabetic patients (P < 0.002). Correlations of diastolic blood pressure increases in diabetic patients with initial pain intensity, standard cardiovascular reflex tests, age, clock time, smoking habits, disease duration, and actual blood glucose concentrations did not reach statistical significance. Pain intensity and diastolic blood pressure increases, however, were correlated to HbA1c concentrations in diabetic patients. CONCLUSIONS: Impaired pain perception is not the cause of the impaired reactions of blood pressure in diabetic patients during the cold pressor test, leaving very early deterioration of either cerebral processing of pain stimuli, cardiac function, efferent sympathetic nerves, or decreased vascular reactivity as possible explanations.