Reduced Complications during Hemodialysis by Automatic Blood Volume Controlled Ultrafiltration

Background

Intradialytic morbid events (IMEs, mostly hypotension) are frequent complications during hemodialysis (HD). This study investigated whether automatic feedback control via adjustment of the ultrafiltration rate reduces IME frequency.

Methods

In this multi-center cross-over study, 56 hypotension-prone patients were treated both with standard HD (sHD, applying a constant ultrafiltration rate) and HD applying a blood volume controlled ultrafiltration rate (cHD). The relative blood volume (RBV) was continuously monitored. The individual relative blood volume limit (RBVcrit) was determined from the measured RBV during initial sHD. During cHD, the ultrafiltration rate was automatically adjusted to keep the actual RBV above RBVcrit.

Results

In 3,081 HD treatments, slightly fewer IMEs were observed during cHD than during sHD (0.785±0.613 versus 0.695±0.547 per treatment, P=0.144). Less symptomatic events were seen during cHD: -13% for symptomatic hypotension (0.594 versus 0.685 per treatment, P=0.120), and -32% for cramps (0.049 versus 0.072 per treatment, P=0.009). Thirty-one patients with the highest IME rate (IME in at least every second treatment) especially benefited from cHD: 1.185±0.554 versus 0.979±0.543 IME per treatment (P=0.004). The reduction in blood pressure (BP) and the increase in heart rate were lower during the treatments with cHD than with sHD: systolic BP: -18.8±26.7 versus -22.2±28.9 mmHg (P=0.007), diastolic BP: -7.8±14.8 versus -9.1±15.3 mmHg (P=0.064), heart rate: 1.8±10.4 versus 2.3±11.6 per minute (P=0.014). Neither treatment duration nor ultrafiltration volume was significantly different between cHD and sHD.

Conclusion

For cHD, less intradialytic morbid events were observed than for sHD, and pre- to post-dialytic changes in blood pressure and heart rate were less pronounced.

Postantibiotic effect and postantibiotic sub-MIC effect of LTX-109 and mupirocin on Staphylococcus aureus blood isolates

The development of new synthetic antimicrobial peptides like LTX-109 provides a new class of drugs for the treatment of Staphylococcus aureus infections. We evaluated LTX-109 and mupirocin for pharmacodynamic parameters against 10 methicillin-resistant S. aureus isolates. The postantibiotic effect (PAE) is defined as the length of time that bacterial growth is suppressed following a brief exposure to an antibiotic. We also determined the sub-MIC effect (SME) which measures the direct effect of subinhibitory levels on strains that have not previously been exposed to antibiotics. The postantibiotic sub-MIC effect (PA-SME) is a combination of the PAE and SME. LTX-109 had an average PAE of 5·51 h vs 1·04 h for mupirocin. The PA-SME of LTX-109 ranged from 2·51 to 9·33 h as the concentration increased from 0·2 to 0·4 times the minimal inhibitory concentration (MIC). The PA-SME range for mupirocin was 0·93-2·58 h. LTX-109, as compared to mupirocin, demonstrated prolonged time of effect for these pharmacodynamic parameters, which supports persistent activity for several hours after the drug is no longer present or is below the MIC. The pharmacodynamic parameters studied here suggest that LTX-109 is less likely than mupirocin to generate resistance to S. aureus.

SIGNIFICANCE AND IMPACT OF THE STUDY

Resistant bacterial infections continue to be a challenge for clinicians. Identification of antibiotics with pharmacodynamic advantages may be beneficial in the treatment of these infections. An antibiotic with a longer postantibiotic effect may be able to be administered less frequently resulting in improved adherence. In this study, a new synthetic antimicrobial peptide, LTX-109, demonstrated a more prolonged time for LTX-109 than mupirocin against methicillin-resistant Staphylococcus aureus.

[Outcome Quality in Medical Rehabilitation: Relationship Between "Patient-Reported Outcomes" (PROs) and Social Security Contributions]

Aim of the Study The outcome quality of medical rehabilitation is evaluated often by "Patient Reported Outcomes" (PROs). It is examined to what extent these PROs are corresponding with "hard" or "objective" outcomes such as payments of contributions to social insurance. Methods The "rehabilitation QM outcome study" includes self-reports of patients as well as data from the Rehabilitation Statistics Database (RSD) of the German pension insurance Baden-Wurttemberg. The sample for the question posed includes N=2 947 insured who were treated in 2011 in 21 clinics of the "health quality network" and who were either employed or unemployed at the time of the rehabilitation application (e. g. the workforce or labour force group, response rate: 55%). The sample turned out widely representative for the population of the insured persons. Results PROs and payment of contributions to pension insurance clearly correspond. In the year after the rehabilitation improved vs. not improved rehabilitees differed clearly with regard to their payments of contributions. Conclusions The results support the validity of PROs. For a comprehensive depiction of the outcome quality of rehabilitation PROs and payments of contributions should be considered supplementary.

Five-year outcome of proximal femoral endoprosthetic arthroplasty for non-tumour indications

OBJECTIVES

A possible solution for the management of proximal femoral bone loss is a modular femoral endoprosthesis (EPR). Although the outcome of EPRs in tumour surgery has been well described, the outcome of their use in revision hip surgery has received less attention. The aim of this study was to describe the outcome of using EPR for non-neoplastic indications.

METHODS

A retrospective review of 79 patients who underwent 80 EPRs for non-neoplastic indications was performed, including the rates of complication and survival and the mean Oxford Hip Scores (OHS), at a mean of five years post-operatively. The mean age at the time of surgery was 69 years (28 to 93) and the mean number of previous operations on the hip was 2.4 (0 to 17). The most common indications for EPR implantation were periprosthetic joint infection (PJI) (n = 40), periprosthetic fracture (n = 12) and failed osteosynthesis of a proximal femoral fracture or complex trauma (n = 11).

RESULTS

Salvage was achieved in all patients. A total of 25 patients (25 EPRs, 31.6%) had a complication, the most common being infection (n = 9) and dislocation (n = 3). Further surgery was required for 18 EPRs (22%), nine of which were revision procedures. The five year survival of the EPR was 87% (95%CI: 76% to 98%). The mean OHS was 28 (4 to 48). Inferior survival and outcomes were seen in EPRs which were performed for the treatment of infection. However, the eradication of infection was achieved in 33 of the 40 (82.5%) which were undertaken for this indication.

CONCLUSION

We recommend the continued use of proximal femoral EPRs for non-neoplastic indications, including PJI. Cite this article: Bone Joint J 2016;98-B:1463-70.

Pregnancy screening prior to chemotherapy administration

A retrospective case notes review was performed to determine compliance with screening for undetected pregnancy prior to commencement of chemotherapy at Flinders Medical Centre. All female patients aged 18-55 who commenced chemotherapy between January and December 2014 were included. During the first 12 months, for women identified as having childbearing potential, pre-chemotherapy pregnancy screening was performed only in 40% of patients under 40 years and in 20.5% of the entire age range.

[Finite Element Modelling of the Eye for the Investigation of Accommodation]

Background: Accommodation research increasingly uses engineering methods. This article presents the use of the finite element method in accommodation research. Material and Methods: Geometry, material data and boundary conditions are prerequisites for the application of the finite element method. Published data on geometry and materials are reviewed. It is shown how boundary conditions are important and how they influence the results. Results: Two dimensional and three dimensional models of the anterior chamber of the eye are presented. With simple two dimensional models, it is shown that realistic results for the accommodation amplitude can always be achieved. More complex three dimensional models of the accommodation mechanism - including the ciliary muscle - require further investigations of the material data and of the morphology of the ciliary muscle, if they are to achieve realistic results for accommodation. Discussion and Conclusion: The efficiency and the limitations of the finite element method are especially clear for accommodation. Application of the method requires extensive preparation, including acquisition of geometric and material data and experimental validation. However, a validated model can be used as a basis for parametric studies, by systematically varying material data and geometric dimensions. This allows systematic investigation of how essential input parameters influence the results.

Towards the development of a hybrid-integrated chip interferometer for online surface profile measurements

Non-destructive testing and online measurement of surface features are pressing demands in manufacturing. Thus optical techniques are gaining importance for characterization of complex engineering surfaces. Harnessing integrated optics for miniaturization of interferometry systems onto a silicon wafer and incorporating a compact optical probe would enable the development of a handheld sensor for embedded metrology applications. In this work, we present the progress in the development of a hybrid photonics based metrology sensor device for online surface profile measurements. The measurement principle along with test and measurement results of individual components has been presented. For non-contact measurement, a spectrally encoded lateral scanning probe based on the laser scanning microscopy has been developed to provide fast measurement with lateral resolution limited to the diffraction limit. The probe demonstrates a lateral resolution of ∼3.6 μm while high axial resolution (sub-nanometre) is inherently achieved by interferometry. Further the performance of the hybrid tuneable laser and the scanning probe was evaluated by measuring a standard step height sample of 100 nm.

Possible reasons for early artificial bone failure in biomechanical tests of ankle arthrodesis systems

In order to demonstrate the influence of the boundary conditions in experimental biomechanical investigations of arthrodesis implants two different models were investigated. As basic model, a simplified finite element model of the cortical bone was used in order to compare the stress values with (Model 1) and without (Model 2) allowing horizontal displacements of the load application point. The model without constraints of horizontal displacements showed considerably higher stress values at the point of failure. Moreover, this investigation shows that the boundary conditions (e.g. constraints) have to be carefully considered, since simplifications of the reality with experimental tests cannot always be avoided.

Formative evaluation of a proposed mHealth program for childhood illness management in a resource-limited setting in Peru

OBJECTIVE

To conduct a formative evaluation of a proposed mobile health (mHealth) program designed to educate caregivers about management of common childhood illnesses.

METHODS

A cluster-randomized sample (n = 220) of mothers in Cono Norte, Arequipa, Peru with at least one child under five completed an iPad-based survey. This descriptive study examined trends in mobile phone ownership and feasibility of and interest in mHealth across sociodemographic categories. Fisher's exact tests were used to evaluate associations. Univariate logistic regression models were fitted to calculate odds ratios and 95% confidence intervals.

RESULTS

Of 220 participants, 82.3% and 95.0% reported mobile phone ownership and access, respectively. Ownership was significantly associated with educational level (P = 0.031); however, even among mothers with the lowest education, ownership approached 80%. Educational level and age, respectively, were associated with the ability to open (P < 0.001; P < 0.001), read (P < 0.001; P < 0.001), write (P < 0.001; P < 0.001), and send (P = 0.006; P = 0.047) text messages. Over 85% of mothers were interested in using their mobile phones to receive health advice for their child and to seek help during illness. Regression analyses revealed that ability to use a mobile phone was positively associated with the mother's intention to participate in the mHealth program.

CONCLUSIONS

The study findings confirm widespread access to mobile phones and sufficient ability to utilize text messaging within this population of caregivers. In addition to access and feasibility, high levels of interest in using mobile phones for health-related purposes suggest the potential value associated with an mHealth program designed to improve childhood illness management in this community.

Die Kinetik des thermischen Zerfalls von ClNO2 / Thermal Decomposition of ClNO2

ClNO2 decomposes incompletely at temperatures between 353 K and 373 K in the nonpolar inert solvent C7F15Cl according to

2 ClNO2=2 NO2+Cl2. (a)

Some ClNO is formed as by-product according to

2 ClNO2 = 2 ClNO+O2 . (b)

The reactions were followed photometrically by the arising NO2 . The time dependence of the brutto-reaction is described on the basis of the reaction scheme

ClNO2⇄NO2+Cl (1, - 1); NO3+NO2⇄NO+O2+NO2 (5, - 5);

ClNO2+ClNO2⇄Cl2+2NO2 (2, - 2); NO+ClNO2⇄ClNO+NO2 (6, - 6);

Cl+ClNO2⇄Cl2+NO2 (3, - 3); ClNO+ClNO2⇄NO±Cl2+NO2 (7, - 7);

NO2+ClNO2⇄NO3±ClNO (4, - 4); Cl+ClNO⇄Cl2+NO (8, - 8).

Arrhenius parameters for the steps (1) and (2) were obtained:

A1/s-1 = 1016.47±0.78, E1/kJ mol-1 = 152.3 ± 5.4;

A2/cm3 mol-1 s-1 = 1012.99±0.02 E2/kJ mol-1 = 88.7 ± 0.8.

The other parameters entering the rate equations were determined at 373 K as k-1/k3 = 1.5 ± 0.3; k4/cm3 mol-1 s-1 = 0.17; k7/cm3 mol-1 s-1 = 11.2. The enthalpies and entropies of the overall reactions (a), (b) and N2O4 = 2 NO2 (c) were measured directly (c) or indirectly:

(a) (b) (c)

⊿RH/kJ mol-1 46.4 83.7 65.3

⊿RS/J K -1 mol-1 61.8 85.7 97.8

(standard state 1 mol cm-3, T = 363 K).

Former investigations of the reaction in the gas phase and in solution which were interpreted exceptionally by step (1) followed by the fast step (3) are now interpreted on the basis of the new reaction scheme discussed here and are found to be consistent with it.

Zur Frage des Masseneffekts bei der lonenwanderung in Lösungen

Die Trennung der im Ionenradius fast übereinstimmenden seltenen Erden Y und Dy durch Gegenstrom-Ionenwanderung führt zur kathodenseitigen Anreicherung nicht des leichten Yttriums (At.-Gew. 88,9), sondern des schweren Dysprosiums (At.-Gew. 162,5). Ein gegenstromelektrolytischer Trennversuch, bei welchem ein verdünnt in Wasser gelöstes terbiumbromidhaltiges YBr3- DyBr3-Gemisch als Elektrolytflüssigkeit diente, ergab die als Beweglichkeitsverhältnisse interpretierbaren Einzeltrennfaktoren wY/wDy=0,9930 und wY/wTb = 0,9889.

Der Befund kann auf der Grundlage von LENARDS gaskinetischer Theorie der Ionenwanderung, deren Gültigkeit an dem für Isotopengemische vorliegenden experimentellen Material eingehend geprüft wird, qualitativ und quantitativ als gemischter Radien- und Masseneffekt verstanden werden.

Auf eine neue Möglichkeit der Bestimmung von Solvatationszahlen aus Isotopieeffekten der Ionenwanderung wird hingewiesen.

Bestimmung der Bildungsenthalpie von Nitroxychlorid (Chlornitrat, NO3Cl) als Beitrag zur Deutung der Kinetik des thermischen NO3Cl-Zerfalls in der Gasphase und in der Lösungsphase / Determination of the Enthalpy of Formation of nitroxy Chloride (Chlorine Nitrate, NO3Cl). A Contribution to the Interpretation of the Kinetics of the Thermal Decomposition of NO3Cl in the Gas Phase and in Solution

The dissociation energy values ⊿H0298(ClO- NO2) = 25.87 kcal mol-1 and ⊿H0 0(ClO-NO2),0 = 24.8 kcal mol-1 were derived from the standard enthalpy of formation of nitroxy chloride (NO3CI) ⊿Hf0 = 6.28 kcalmol-1 which has been determined from the reaction enthalpy of the gas phase reaction NOCI + NO3CI = 2 NO2 + Cl2. With the help of these data it was possible to show that in the thermal decomposition of NO3Cl, for which the overall reaction is NO3Cl = NO2 +½O2 + ½Cl2. at temperatures around 100 °C the equilibrium NO3Cl ⇄ NO2 + OCl is established. At the beginning of the reaction, there exists such a high OCl concentration that the decomposition occurs practically exclusively by the reactions

OCl + OCl + M ⇄Cl2O2 + M,

Cl2O2 + M → Cl2 + O2+M

and

OCl + OCl → Cl + OOCl,

the last of which is followed by Cl-consuming reaction steps, e.g. CI + NO3CI → NO3 + Cl2, apparently initiating chain reactions. The reaction step NO2 + NO3Cl → NO3 + NO2Cl, postulated from an investigation of the kinetics in a nono-polar inert solvent, and its daughter reactions probably occur for the gas phase reaction as well.

Multiple-aetiology enteric infections involving non-O157 Shiga toxin-producing Escherichia coli--FoodNet, 2001-2010

We describe multiple-aetiology infections involving non-O157 Shiga toxin-producing Escherichia coli (STEC) identified through laboratory-based surveillance in nine FoodNet sites from 2001 to 2010. A multiple-aetiology infection (MEI) was defined as isolation of non-O157 STEC and laboratory evidence of any of the other nine pathogens under surveillance or isolation of >1 non-O157 STEC serogroup from the same person within a 7-day period. We compared exposures of patients with MEI during 2001-2010 with those of patients with single-aetiology non-O157 STEC infections (SEI) during 2008-2009 and with those of the FoodNet population from a survey conducted during 2006-2007. In total, 1870 non-O157 STEC infections were reported; 68 (3.6%) were MEI; 60 included pathogens other than non-O157 STEC; and eight involved >1 serogroup of non-O157 STEC. Of the 68 MEI, 21 (31%) were part of six outbreaks. STEC O111 was isolated in 44% of all MEI. Of patients with MEI, 50% had contact with farm animals compared with 29% (P < 0.01) of persons with SEI; this difference was driven by infections involving STEC O111. More patients with non-outbreak-associated MEI reported drinking well water (62%) than respondents in a population survey (19%) (P < 0.01). Drinking well water and having contact with animals may be important exposures for MEI, especially those involving STEC O111.

Fracture near press-on interlocking enhances callus mineralisation in a sheep midshaft tibia osteotomy model

INTRODUCTION

Factors which impair fracture healing after intramedullary (IM) nailing of long bone fractures range from surgical and biological factors to mechanical parameters. Mechanical parameters known to prolong bony consolidation are share forces at the site of the fracture. Fracture near press-on interlocking reduces share forces directly at the fracture site and is hypothesised to enhance callus mineralisation. A sheep model of midshaft tibia osteotomies evaluates the technique.

MATERIALS AND METHODS

Fracture near interlocking was achieved by surfacing a custom made nail with special hutches that enable firm screw seating on top of the nail ("golf ball" structure). Virtual (fine element analysis (FEA)) and biomechanical pilot tests were completed before in vivo application in 12 adult female German black sheep. Midshaft tibia osteotomy was performed creating a subcritical 7 mm gap for delay in union. One group (n=6) was treated with reamed IM nailing employing the custom made nail and in addition to proximal and distal standard interlocking a fracture near press on interlocking was employed. A second group of six sheep without additional press on interlocking served as control. 10 weeks after operation the quality of fracture healing was determined by micro-CT.

RESULTS

The FEA showed that axial loading up to 4000N did not lead to implant fatigue. Fracture near press on interlocking led to significantly more callus mineralisation compared to the conventional interlocking procedure (0.567 g/cm(3) ± 0.106 g/cm(3) versus 0.434 g/cm(3) ± 0.0836 g/cm(3), p=0.043).

CONCLUSIONS

Fracture near press on interlocking increases callus mineralisation in a subcritical osteotomy model in sheep. The results indicate that the reduction of share forces at the fracture site after nailing procedures may be effective in reducing the time until bony consolidation.