Post-corrosive injuries of upper gastrointestinal tract.

Acute poisonings with corrosive substances may cause serious chemical injuries to upper gastrointestinal tract, the most common location being the esophagus and the stomach. If the patient survives the acute phase of the poisoning, regenerative response may result in esophageal and/or gastric stenosis and increased risk for esophageal cancer. Acute corrosive intoxications pose a major problem in clinical toxicology since the most commonly affected population are the young with psychic disorders, suicidal intent and alcohol addiction. In establishing the diagnosis of acute corrosive poisonings, the severity of the post-corrosive endoscopic changes of the esophagus, stomach and duodenum is of major importance. According to Holinder and Fridman classification, post-corrosive endoscopic changes are classified in three degrees: First degree--superficial damage associated with hyperthermia, epithelial desquamation and mucous edema. Second degree--transmucous damage affecting all of the mucosal layers, followed by exudation, erosions and ulcerations. Third degree--transmural damage associated with ulcer's penetration in the deep layers of the tissue and neighboring organs. Severity of the lesions depends on the nature, quantity and concentration of the corrosive substance, the duration of exposure and current state of the exposed organs. Most often caustic injuries occur to the esophagus and stomach since the corrosive substance remains there for a longer period of time. Treatment of the acute corrosive intoxications include: neutralization of corrosive agents, antibiotics, corticosteroids, anti-secretory therapy, nutritional support, collagen synthesis inhibitors, esophageal dilation and stent placement, and surgery. The most common complications that may appear are: perforation, gastrointestinal bleeding, sepsis, esophageal strictures and stenosis, stenosis of gastric antrum and pylorus, cancer of the esophagus and the stomach. Today, owing to the substantially enhanced diagnostic and therapeutic approach, the mortality percentage has been reduced from 20% to 1-5%. Women more often than men are intoxicated with corrosive substances; suicidal poisonings prevail; the most abused agents are hydrochloric acid (HCl) and sodium hydroxide; intoxications are more common in children (80% out of the total number of intoxications). In spite of the preventive measures for restriction of the trade with corrosive substances, standardization of their concentration and protective safety bottle caps, still the number of corrosive intoxications, the percentage of post-corrosive complications and the handicap are high. Acute corrosive intoxications are the leading cause of death in clinical toxicology.

Increased silicon levels in dialysis patients due to high silicon content in the drinking water, inadequate water treatment procedures, and concentrate contamination: a multicentre study.

BACKGROUND: Although silicon is considered as an essential element, little is known about the basic effects and clinical significance of increased concentrations of the element in dialysis patients. METHODS AND RESULTS: In a multicentre study we found silicon levels in haemodialysis (HD) patients to be markedly increased. In these patients silicon concentrations were significantly higher than those noted in subjects with normal renal function as well as in patients with chronic renal failure not yet in dialysis and patients treated by continuous ambulatory peritoneal dialysis (CAPD). Moreover we noted that in both HD and CAPD patients mean silicon levels differed from one centre to another. Also, was there in the HD population a significant difference in serum silicon levels among patients from different countries. In HD patients differences in serum silicon levels were either due to the use of silicon contaminated dialysis fluids or an increased oral intake of the element mainly originating from the high silicon content of the drinking water. Silicon contamination of the dialysis fluid was found to be due to either the use of reverse osmosis membranes that insufficiently retain the element during water treatment or by the addition of concentrates containing high amounts of silicon. Using a recently developed high-performance liquid chromatographic/atomic absorption spectrophotometric (HPLC/ETAAS) hybrid technique, we found silicon in serum to be present as a low-molecular-weight non-protein-bound component, which in the presence of a low silicon dialysate is adequately removed during treatment. CONCLUSIONS: The clinical relevance of increased serum silicon levels is not yet known and as such deserves further investigation. In view of the controversy that exists on the element's assumed protective as well as toxic role in the development of some (aluminium-related) neurodegenerative diseases and its vital role in bone formation, monitoring of the silicon levels in serum, tap water, and dialysis fluids might become important.