Minor Burns: A Review

Two million burns occur annually in the USA, of which 95% aretreated in an out-patient setting. The treatment of burns iscontroversial. There are few data from controlled studies toprovide rational guidelines for the frequency of both dressingchanges and patient visits for the physician. Conclusions concerninginfection drawn from studies on major burns are misleading whenapplied to the management of minor burns. Trauma to regeneratingepithelium caused by frequent dressing change is of relativelyless importance in treating major burns, because the controlof infection is of overriding importance. In the treatment ofminor burns, the traumatic consequences of too frequent changesof dressing may assume greater importance. There is a clearneed to study the variables in the treatment of minor burnsand to generate criteria for their clinical management thatare distinct from those of major burn management. Collaborativestudies of out-patient populations by providers of primary healthcare are suggested as a useful approach to such investigation.The effects of several additional therapies are reviewed, includinginitial cold therapy, debridement of blisters and antibiotics.     

Structural Requirements for the Direct and Cytochrome P450-dependent Reaction of Cyclic α,β-Unsaturated Carbonyl Compounds with Glutathione: a Study with Coumarin and Related Compounds

Abstract— The interaction of glutathione (GSH) with coumarin, or one of a series of compounds related to coumarin, was assessed in the absence and presence of liver microsomes (direct reaction and indirect reaction, respectively) to determine the structural requirements for direct and mono-oxygenase-mediated reaction of cyclic α,β-unsaturated carbonyls with GSH. Acrolein was used as a positive control for the direct reaction, and produced complete or nearly complete depletion of GSH under all assay conditions. 5,6-Dihydro-2H-pyran-2-one and 2-cyclohexen-1-one also produced substantial depletion of GSH in the direct reaction, which was not increased by the addition of liver microsomes. Coumarin, 2H-pyran-2-one and precocene I (a substituted pyran lacking the 2-one structure) were not substrates for the direct reaction but did cause depletion of GSH when incubated in the presence of rat or human liver microsomes. These depletions were dependent on a functioning mono-oxygenase system as judged by the effects of omission of cofactors, addition of competitive or inactivating inhibitors of cytochrome P450, and induction. Dihydrocoumarin, ?-valerolactone, cyclohexanone and 4H-pyran-4-one were not substrates for either the direct or indirect reaction. These findings are rationalized on the basis of a direct nucleophilic attack of GSH on the α,β-centre of the α,β-unsaturated carbonyl compounds, which is hindered by benzenoid resonance in coumarin and 2H-pyran-2-one, for which enzyme-mediated reaction with GSH, probably via a 3,4-epoxide, is the favoured mechanism.     

Automatic Implantable Cardioverter Defibrillator/Permanent Pacemaker Interaction: Loss of Pacemaker Capture Following AICD Discharge

A 78-year-old man treated with amiodarone for recurrent ventricular tachycardia, had sequential placement of a bipolar VVI pacemaker and an automatic implantable cardioverter defibrillator (AICD). During defibrillation threshold testing, there was failure to capture of the pacer in the post-shock period. The time of failure to capture appeared energy-related: the greater the energy delivered, the longer the failure to capture. Careful attention will be necessary in constructing combined AICD/pacemaker units.     

Computer-Assisted Design of an Implantable, Intrathoracic Artificial Lung

Abstract: A semiempirical mathematical model of convective oxygen transport is used to design a new, low pressure loss, implantable artificial lung that could be used as a bridge to lung transplantation in patients with advanced respiratory failure. The mass transfer and flow friction relations pertinent to the design of a cross–flow hollow fiber membrane lung are described. The artificial lung is designed to transfer over 200 ml/min of oxygen at blood flow rates up to 5 L/min. A compact design and a blood-side pressure loss of <15 mm Hg allows the device to be implanted in the left chest without the need for a prosthetic blood pump. Surgical implantation of the artificial lung would require the creation of inflow and outflow anastomoses. Oxygen would be supplied via an external source. Blood properties, operating conditions, and empirically determined mass transfer and flow properties are all specified and input into a computer program that numerically solves the design equations. Computer–generated values for the device frontal area, blood path length, and fiber surface area are thereby obtained. The use of this computer–assisted design minimizes the need for extensive trial–and–error testing of prototype devices. Results from in vitro tests of a prototype implantable lung indicate that the mathematical model we describe is an accurate and useful tool in the design of hollow fiber artificial lungs.     

FDA-Approved Sodium Tetradecyl Sulfate (STS) versus Compounded STS for Venous Sclerotherapy

BACKGROUND: In the area of endovenous chemical ablation (sclerotherapy), there has been much debate regarding sclerosant quality and efficacy. Only sodium tetradecyl sulfate (STS) has garnered Food and Drug Administration (FDA) approval in the United States. OBJECTIVE: The primary objective of this study was to compare clinical performance measures of compounded STS from 27% industrial-strength stock (compounded STS) versus FDA-approved Sotradecol (Bioniche Pharma USA, Inc., Belleville, Ontario, Canada). MATERIALS AND METHODS: Phase I of this study focused on the chemical composition of the drugs, whereas Phase II studied the ablative abilities of the two drugs at comparable concentrations of 3%. RESULTS: We documented the presence of various impurities in compounded STS. No impurities in AngioDynamics STS were found. Our studies suggest that compounded STS may have significant variation in concentration. The AngioDynamics STS concentration was found to be manufactured within a tight tolerance. Segments of incomplete ablation were more frequent in the compounded STS group when compared to the AngioDynamics STS group. This reached statistical significance (p=.02). Primary closure using the Kaplan-Meier statistic demonstrated a trend in the favor of AngioDynamics STS when compared to compounded STS. CONCLUSION: When product quality, efficacy, and liability are carefully considered, we conclude that it would behoove physicians to use pharmaceutical-grade, FDA-approved sclerosant when treating their patients.