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Biomedical subjects

M Tenenbein

Publications and source records attributed to M Tenenbein.

At least 73 records · Page 4Linked to original sources
PubMed1991

The total iron-binding capacity in iron poisoning. Is it useful?

Traditionally, a serum iron concentration in excess of the total iron-binding capacity (TIBC) is considered as an indication for deferoxamine therapy in acute iron poisoning. We observed a reversible elevation of the TIBC in patients with iron poisoning that coincided with their acute hyperferremia and have hypothesized that this is a laboratory aberration. We tested this hypothesis in vitro and found that the addition of iron to test serum samples produced a related increase in the TIBC, and alteration of the assay by providing additional adsorbent prevented this occurrence. We also evaluated the reproducibility of the TIBC as performed by 500 laboratories on 10 different reference samples. The mean coefficient of variation was 16%, which was unsatisfactory. We concluded that the TIBC should not be used in the decision for the initiation of deferoxamine therapy in acute iron poisoning. Furthermore, high TIBC values that are occasionally seen in patients with iron poisoning should not be considered as providing a protective effect.

Binding Sites↗
PubMed1991

Multiple doses of activated charcoal: time for reappraisal?

Multiple-dose charcoal therapy has become a popular treatment for many overdoses. It is generally perceived as a simple, inexpensive, effective, and safe procedure that decreases morbidity and mortality by enhancing drug excretion. However, increased drug clearance has been shown definitively for only a few drugs, and improved outcome has not been demonstrated conclusively for any overdose. Recently, there have been several reports of complications due to this intervention. The role of this pharmacologic curiosity in the management of the acutely poisoned patient requires reassessment.

Charcoal↗
PubMed1991

An analysis of occupational blood lead trends in Manitoba, 1979 through 1987.

BACKGROUND: While regulations for workplace lead exposure become more strict, their effectiveness in decreasing blood lead concentrations and the method by which this is attained have not been evaluated. METHODS: An analysis was conducted of 10,190 blood lead samples from employees of 10 high-risk workplaces collected in Manitoba, 1979-87, as part of regulated occupational surveillance. RESULTS: A significant decrease in blood lead concentrations was observed overall as well as for each individual company. A 1979 government regulation to reduce blood lead to below 3.38 mumol/L (70 micrograms/dl) was followed by a drop in blood lead concentrations; a 1983 order to reduce blood leads to below 2.90 mumol/L (60 micrograms/dl) was not followed by such a drop. Longitudinal analysis by individual workers suggested that companies were complying by use of administrative control, i.e., removing workers to lower lead areas until blood lead levels had fallen, then returning them to high lead areas. CONCLUSION: Focusing upon blood lead as the sole criterion for compliance is not effective; regulations must specifically require environmental monitoring and controls. Biological surveillance serves as "back-up" to environmental surveillance and this database illustrates the usefulness of a comprehensive centralized surveillance system.

Air Pollutants, Occupational↗
PubMed1991

An objective criterion for the cessation of deferoxamine therapy in the acutely iron poisoned patient.

The criteria for the cessation of deferoxamine therapy in the acutely iron poisoned patient are vague and imprecise. We have developed a urinary iron assay which is not confounded by the presence of deferoxamine and have established a reference range in non-iron poisoned deferoxamine treated human volunteers. When reported as a urine iron to creatinine ratio the results from isolated urine specimens can be utilized to guide deferoxamine therapy. This method is rapid, simple and inexpensive and utilizes equipment and reagents found in laboratories already providing emergency serum iron concentrations. We have found this assay to be useful as a criterion for the cessation of deferoxamine therapy in the acutely iron poisoned patient and as an objective indicator of a positive deferoxamine chelation challenge.

Adult↗
PubMed1991

Diltiazem overdose: pharmacokinetics of diltiazem and its metabolites and effect of multiple dose charcoal therapy.

We describe a 38 year-old female who ingested 900 mg of diltiazem. She experienced hypotension, bradycardia and heart block but responded well to supportive care that included normal saline infusion and vasopressors. Calcium administration was not beneficial. Serial plasma concentrations of diltiazem, N-demethyldiltiazem and desacetyldiltiazem were quantified. By comparing the elimination half-life for diltiazem with historical controls, it is concluded that multiple dose charcoal therapy was not beneficial for our patient.

Adult↗
PubMed1991

Clinical spectrum of sulfonylurea overdose and experience with diazoxide therapy.

We retrospectively reviewed our 10-year experience with the management of sulfonylurea overdose. There were 40 overdoses in 37 patients aged 1 to 78 years, with two deaths and one patient being left in a chronic vegetative state. Blood sugar levels ranged from normal to severe recalcitrant hypoglycemia. Maximal duration of recurrent hypoglycemia was 82 hours. In 21 of 31 patients with hypoglycemia, response to hypertonic glucose therapy was poor, resulting in recurrent hypoglycemia. Six of these patients were treated with intravenous diazoxide and had prompt correction. Overdose of sulfonylurea drugs may produce severe, protracted hypoglycemia poorly responsive to hypertonic glucose therapy. Treatment with diazoxide is rational and effective and may be lifesaving.

Diazoxide↗
PubMed1990

The toddler's fracture revisited.

The authors have reviewed our experience with 37 cases of toddler's fracture. This fracture of the distal tibia occurs in 1 to 4 year-old-children. History of trauma is usually trivial and the physical findings and radiological appearance are often subtle. The latter consists of a faint oblique lucent line crossing the distal tibia and terminating medially. It is usually seen on the anteroposterior view, poorly seen on the lateral and well seen on the internal oblique. Initial radiographs may be normal. A similar fracture of the midshaft of the tibia was associated with child abuse. Treatment consists of immobilization for a few weeks to protect the limb and to relieve pain. Diagnosis requires a high index of suspicion and is important because it obviates the need for investigations to rule out more sinister etiologies such as tumor or infection. The finding of a midshaft tibial fracture may indicate child abuse.

Accidents, Home↗
PubMed1990

Interaction between whole-bowel irrigation solution and activated charcoal: implications for the treatment of toxic ingestions.

STUDY OBJECTIVES: The purpose of this study was to address the issues of safety and efficacy of combining whole-bowel irrigation and activated charcoal administration for the treatment of toxic ingestions. STUDY DESIGN: Two in-vitro studies were performed. In the first, serial ratios of polyethylene glycol (PEG) and activated charcoal (AC) powders were added to water and the solutions were analyzed for PEG concentration and osmolality. In the second, serial ratios of a pharmaceutical bowel irrigation solution and an AC preparation were combined with a constant amount of salicylic acid. Solution osmolalities, PEG, and salicylic acid concentrations were then quantified. RESULTS: Adsorption of PEG powder by AC was demonstrated; however, changes in solution osmolality were negligible. Thus, concurrent administration of these therapies appears safe. However, combining bowel irrigation solution with AC resulted in decreased salicylic acid adsorption. This was especially so with smaller amounts of AC that would pertain more to the smaller doses of AC used for multiple-dose charcoal therapy. CONCLUSION: If these in-vitro data are applicable to overdose patients, the administration of a routine initial charcoal dose to those who will be treated with whole-bowel irrigation would be appropriate. However, it is unlikely that the addition of multiple-dose charcoal therapy to whole-bowel irrigation would provide additional benefit for the patient.

Administration, Rectal↗
PubMed1990

Gastrointestinal pathology in adult iron overdose.

The gastrointestinal effects of iron overdose have been described in children. They may occur acutely, ranging in severity from mucosal injury to complete infarction, or several weeks later, as obstruction due to stricture formation. They typically occur in the stomach or proximal small bowel. We describe an adult example of both, each occurring in the distal portion of the small intestine. Both patients had ingested enteric-coated iron preparations and both experienced significant, protracted abdominal pain. Thus adults as well as children are at risk for severe gastrointestinal complications after iron overdose. Significant protracted abdominal pain should alert the clinician of its possibility. Damage to distal areas of the bowel can occur with complete sparing of proximal portions particularly if the iron is an enteric-coated preparation.

Abdominal Pain↗
PubMed1990

Does multiple-dose charcoal therapy enhance salicylate excretion?

Multiple-dose charcoal therapy has been shown to increase the excretion of some drugs. This study assesses the effects of this intervention on salicylate excretion in the postabsorptive phase. Ten human volunteers participated in this randomized, controlled, crossover, two-limbed protocol. On two occasions each volunteer ingested 2880 mg of aspirin. During the experimental limb, 25 g of activated charcoal was ingested at 4, 6, 8, and 10 hours after drug ingestion. Pharmacokinetic data were derived from serial serum salicylate concentrations, and urinary salicylate excretion was quantified. Treatment effects were 9% and 18%, respectively. Although both are significant, they are clinically modest, making multiple-dose charcoal therapy of questionable value for acute salicylate poisoning. Controlled data demonstrating the clinical efficacy of this therapy are required to validate it as an intervention for this condition.

Adult↗
PubMed1989

Whole bowel irrigation during pregnancy.

Whole bowel irrigation is a routine colonoscopic preparatory procedure. It has been advocated as a method of cleansing the alimentary canal of poisons after acute overdose. Its use during pregnancy has not been described for either indication. We report a case of an iron overdose during the third trimester treated with whole bowel irrigation without complication.

Adolescent↗