Water displacement leg volumetry in clinical studies - A discussion of error sources

<p>Abstract</p> <p>Background</p> <p>Water displacement leg volumetry is a highly reproducible method, allowing the confirmation of efficacy of vasoactive substances. Nevertheless errors of its execution and the selection of unsuitable patients are likely to negatively affect the outcome of clinical studies in chronic venous insufficiency (CVI).</p> <p>Discussion</p> <p>Placebo controlled double-blind drug studies in CVI were searched (Cochrane Review 2005, MedLine Search until December 2007) and assessed with regard to efficacy (volume reduction of the leg), patient characteristics, and potential methodological error sources. Almost every second study reported only small drug effects (≤ 30 mL volume reduction). As the most relevant error source the conduct of volumetry was identified. Because the practical use of available equipment varies, volume differences of more than 300 mL - which is a multifold of a potential treatment effect - have been reported between consecutive measurements. Other potential error sources were insufficient patient guidance or difficulties with the transition from the Widmer CVI classification to the CEAP (Clinical Etiological Anatomical Pathophysiological) grading.</p> <p>Summary</p> <p>Patients should be properly diagnosed with CVI and selected for stable oedema and further clinical symptoms relevant for the specific study. Centres require a thorough training on the use of the volumeter and on patient guidance. Volumetry should be performed under constant conditions. The reproducibility of short term repeat measurements has to be ensured.</p

Early onset of efficacy in patients with functional and motility-related gastrointestinal disorders: A noninterventional study with Iberogast® Frühzeitiger Wirkungsbeginn bei Patienten mit funktionellen und motilitätsbedingten gastrointestinalen Erkrankungen: Eine nichtinterventionelle Studie mit Iberogast®

Summary: STW 5 (Iberogast®; Steigerwald Arzneimittelwerk GmbH, Darmstadt, Germany) contains nine plant extracts and possesses well-documented overall efficacy in functional gastrointestinal disorders (FGID). Little is known about the onset of symptom relief. Twenty-nine centers in Germany recruited 272 patients with established FGID. These patients were treated with STW 5 for approximately 3 weeks in this noninterventional study. Patients assessed the severity of their gastrointestinal complaints before and at defined times after the intake of STW 5 (10 cm visual analogue scale; VAS). Fifteen minutes after the first dose, the severity of gastrointestinal complaints had decreased by 1.4 cm (mean; initial mean: 5.2 of 10 cm). After 1 h, more than 90% of the maximum effect of 3.2 cm on the 10 cm VAS had been reached. Most patients with symptoms experienced a marked improvement within 5, 15 or 30 min of taking STW 5. Absolute improvements were larger in patients with more pronounced baseline complaints. Subgroups with upper (80% of the study population) and lower FGID (20%) did not present major differences. Neither did subgroups by age and duration of complaints. Treatment with STW 5 resulted in rapid improvement of symptoms

Tolerability and effectiveness of an antitrauma cream with comfrey herb extract in pediatric use with application on intact and on broken skin

Objective: The safety of comfrey herbal cream application to broken skin is still a matter of regulatory debate. It was therefore examined in children with intact and with broken skin treated for blunt traumas and sports injuries, with the aim of collecting data for pharmacovigilance and clinical safety assessments. Methods: A total of 712 children (386 children with intact skin and 326 children with abrasions and superficial wounds) were openly treated for up to 2 weeks with 1–5 applications daily of comfrey herb cream after presenting for blunt traumas and sports accidents. The incidence rate of adverse events was calculated, next to a global assessment of treatment effects. Results: No adverse events occurred in the group of children with intact skin, and one intolerability reaction (burning and reddening) was observed after application to broken skin. The overall incidence rate of intolerability reactions per patient was calculated as 0.14% (95% CI 0.00–0.78%) and that of systemic adverse effects as 0.00% (95% CI 0.00–0.42%). Accordingly, the probability of the occurrence of local reactions and systemic adverse events is well below, which is one in 100 treated patients. The global assessment of effects corresponded to previously published experience. Conclusion: These studies confirm an excellent benefit-to-risk ratio for the application of comfrey herb cream in the treatment of blunt traumas and sports injuries in children with intact and with broken skin. Keywords: Comfrey, Symphytum herb extract, Topical application, Safety, Pediatric us

Impact of Hydrophilic Modification of Synthetic Dialysis Membranes on Hemocompatibility and Performance

The dialyzer is the core element in the hemodialysis treatment of patients with end-stage kidney disease (ESKD). During hemodialysis treatment, the dialyzer replaces the function of the kidney by removing small and middle-molecular weight uremic toxins, while retaining essential proteins. Meanwhile, a dialyzer should have the best possible hemocompatibility profile as the perpetuated contact of blood with artificial surfaces triggers complement activation, coagulation and immune cell activation, and even low-level activation repeated chronically over years may lead to undesired effects. During hemodialysis, the adsorption of plasma proteins to the dialyzer membrane leads to a formation of a secondary membrane, which can compromise both the uremic toxin removal and hemocompatibility of the dialyzer. Hydrophilic modifications of novel dialysis membranes have been shown to reduce protein adsorption, leading to better hemocompatibility profile and performance stability during dialysis treatments. This review article focuses on the importance of performance and hemocompatibility of dialysis membranes for the treatment of dialysis patients and summarizes recent studies on the impact of protein adsorption and hydrophilic modifications of membranes on these two core elements of a dialyzer

Hemodiafiltration: Technical and Medical Insights

Despite the significant medical and technical improvements in the field of dialytic renal replacement modalities, morbidity and mortality are excessively high among patients with end-stage kidney disease, and most interventional studies yielded disappointing results. Hemodiafiltration, a dialysis method that was implemented in clinics many years ago and that combines the two main principles of hemodialysis and hemofiltration&mdash;diffusion and convection&mdash;has had a positive impact on mortality rates, especially when delivered in a high-volume mode as a surrogate for a high convective dose. The achievement of high substitution volumes during dialysis treatments does not only depend on patient characteristics but also on the dialyzer (membrane) and the adequately equipped hemodiafiltration machine. The present review article summarizes the technical aspects of online hemodiafiltration and discusses present and ongoing clinical studies with regards to hard clinical and patient-reported outcomes

Hemodiafiltration: Technical and Medical Insights

Despite the significant medical and technical improvements in the field of dialytic renal replacement modalities, morbidity and mortality are excessively high among patients with end-stage kidney disease, and most interventional studies yielded disappointing results. Hemodiafiltration, a dialysis method that was implemented in clinics many years ago and that combines the two main principles of hemodialysis and hemofiltration—diffusion and convection—has had a positive impact on mortality rates, especially when delivered in a high-volume mode as a surrogate for a high convective dose. The achievement of high substitution volumes during dialysis treatments does not only depend on patient characteristics but also on the dialyzer (membrane) and the adequately equipped hemodiafiltration machine. The present review article summarizes the technical aspects of online hemodiafiltration and discusses present and ongoing clinical studies with regards to hard clinical and patient-reported outcomes