Water, electrolytes, vitamins and trace elements - Guidelines on Parenteral Nutrition, Chapter 7

A close cooperation between medical teams is necessary when calculating the fluid intake of parenterally fed patients. Fluids supplied parenterally, orally and enterally, other infusions, and additional fluid losses (e.g. diarrhea) must be considered. Targeted diagnostic monitoring (volume status) is required in patients with disturbed water or electrolyte balance. Fluid requirements of adults with normal hydration status is approximately 30–40 ml/kg body weight/d, but fluid needs usually increase during fever. Serum electrolyte concentrations should be determined prior to PN, and patients with normal fluid and electrolyte balance should receive intakes follwing standard recommendations with PN. Additional requirements should usually be administered via separate infusion pumps. Concentrated potassium (1 mval/ml) or 20% NaCl solutions should be infused via a central venous catheter. Electrolyte intake should be adjusted according to the results of regular laboratory analyses. Individual determination of electrolyte intake is required when electrolyte balance is initially altered (e.g. due to chronic diarrhea, recurring vomiting, renal insufficiency etc.). Vitamins and trace elements should be generally substituted in PN, unless there are contraindications. The supplementation of vitamins and trace elements is obligatory after a PN of >1 week. A standard dosage of vitamins and trace elements based on current dietary reference intakes for oral feeding is generally recommended unless certain clinical situations require other intakes

Protective effect of antioxidative vitamins against lipid eroxidation in liver ischemia and reperfusion

Ischemia and reperfusion (I/R) leads to oxidative stress with free radical formation. With respect to liver surgery and transplantation this can lead to deleterious clinical effects. Protection of the liver against I/R injury is of major concern. Thus, in this study, we examined the effect of an antioxidant vitamin solution (vitamin E, C and ß-carotene) on warm I/R injury. Twelve pigs of the German landrace (7 animals in the vitamin group and 5 untreated controls) were examined in this animal model. Twenty-four hours before laparotomy, the vitamin group was initiated with a single intravenous infusion of the vitamin cocktail. The duration of complete warm ischemia of the liver was 4 hours. Serum liver enzyme levels (AST and ALT) and with thiobarbituric acid reacting substances (TBARS) in liver tissue were measured. Furthermore, immunohistochemical staining of oxidative products (oxidized proteins and 4-hydroxy-nonenal = 4-HNE) in liver tissue was made. The maximum accumulation of oxidized proteins was seen six days postoperatively in the controls whereas in the vitamin group only small amounts were seen. 4-HNE showed a marked accumulation in the controls but was almost not detectable in the vitamin group. TBARS were lower in the vitamin group compared to controls. Although the emulsifier necessary for the vitamin solution leads to increased liver enzyme levels in the vitamin group, the values returned to normal more rapidly. Antioxidant vitamins are able to improve warm I/R liver injury. Oxidative stress is directly verifiable at the tissue level. Future animal experiments as well as clinical trials are necessary to explore the optimization of the combination of antioxidative vitamins for the maximum protection from I/R injury

Physiological effects of oral glucosamine on joint health: Current status and consensus on future research priorities

The aim of this paper was to provide an overview of the current knowledge and understanding of the potential beneficial physiological effects of glucosamine (GlcN) on joint health. The objective was to reach a consensus on four critical questions and to provide recommendations for future research priorities. To this end, nine scientists from Europe and the United States were selected according to their expertise in this particular field and were invited to participate in the Hohenheim conference held in Aug

Self-Consistent Field study of Polyelectrolyte Brushes

We formulate a self-consistent field theory for polyelectrolyte brushes in the presence of counterions. We numerically solve the self-consistent field equations and study the monomer density profile, the distribution of counterions, and the total charge distribution. We study the scaling relations for the brush height and compare them to the prediction of other theories. We find a weak dependence of the brush height on the grafting density.We fit the counterion distribution outside the brush by the Gouy-Chapman solution for a virtual charged wall. We calculate the amount of counterions outside the brush and find that it saturates as the charge of the polyelectrolytes increases

ESPEN micronutrient guideline.

Trace elements and vitamins, named together micronutrients (MNs), are essential for human metabolism. Recent research has shown the importance of MNs in common pathologies, with significant deficiencies impacting the outcome. This guideline aims to provide information for daily clinical nutrition practice regarding assessment of MN status, monitoring, and prescription. It proposes a consensus terminology, since many words are used imprecisely, resulting in confusion. This is particularly true for the words "deficiency", "repletion", "complement", and "supplement". The expert group attempted to apply the 2015 standard operating procedures (SOP) for ESPEN which focuses on disease. However, this approach could not be applied due to the multiple diseases requiring clinical nutrition resulting in one text for each MN, rather than for diseases. An extensive search of the literature was conducted in the databases Medline, PubMed, Cochrane, Google Scholar, and CINAHL. The search focused on physiological data, historical evidence (published before PubMed release in 1996), and observational and/or randomized trials. For each MN, the main functions, optimal analytical methods, impact of inflammation, potential toxicity, and provision during enteral or parenteral nutrition were addressed. The SOP wording was applied for strength of recommendations. There was a limited number of interventional trials, preventing meta-analysis and leading to a low level of evidence. The recommendations underwent a consensus process, which resulted in a percentage of agreement (%): strong consensus required of >90% of votes. Altogether the guideline proposes sets of recommendations for 26 MNs, resulting in 170 single recommendations. Critical MNs were identified with deficiencies being present in numerous acute and chronic diseases. Monitoring and management strategies are proposed. This guideline should enable addressing suboptimal and deficient status of a bundle of MNs in at-risk diseases. In particular, it offers practical advice on MN provision and monitoring during nutritional support

Use of polyethylene glycol coatings for optical fibre humidity sensing

Humidity induced change in the refractive index and thickness of the polyethylene glycol (PEG) coatings are in situ investigated for a range from 10 to 95%, using an optical waveguide spectroscopic technique. It is experimentally demonstrated that, upon humidity change, the optical and swelling characteristics of the PEG coatings can be employed to build a plastic fibre optic humidity sensor. The sensing mechanism is based on the humidity induced change in the refractive index of the PEG film, which is directly coated onto a polished segment of a plastic optical fibre with dip-coating method. It is observed that PEG, which is a highly hydrophilic material, shows no monotonic linear response to humidity but gives different characteristics for various ranges of humidity levels both in index of refraction and in thickness. It undergoes a physical phase change from a semi-crystal line structure to a gel one at around 80% relative humidity. At this phase change point, a drastic decrease occurs in the index of refraction as well as a drastic increase in the swelling of the PEG film. In addition, PEG coatings are hydrogenated in a vacuum chamber. It is observed that the hydrogen has a preventing effect on the humidity induced phase change in PEG coatings. Finally, the possibility of using PEG coatings in construction of a real plastic fibre optic humidity sensor is discussed. (C) 2008 The Optical Society of Japan