Compatibility of Intravenous Fat Emulsion with Antibiotics for Secondary Piggyback Infusion

Background: The Guidelines for Parenteral and Enteral Nutrition in Japan state that parenteral fat emulsion can be infused through a secondary administration set. We tested the compatibility of fat emulsion with antibiotics in piggyback infusions in terms of changes in the size distribution of fat particles. Methods: Test mixtures of 5% glucose solution, fat emulsion, and 25 antibiotic agents were prepared in the ratio appropriate for piggyback infusion (33: 10: 40) and analyzed serially for the number of fine particles by size using a light-shielded automatic fine particle counter. Results: No marked changes were observed in the 12 β-lactam antibacterial drugs, clindamycin phosphate, teicoplanin, trimethoprim/sulfamethoxazole, and micafungin sodium even at 24 h after preparation. The particle size in the mixture containing vancomycin hydrochloride, levofloxacin hydrate, metronidazole, and fluconazole gradually increased after preparation. The particle size in the mixture containing gentamicin sulfate, arbekacin sulfate, minocycline hydrochloride, ciprofloxacin, and fosfomycin sodium changed significantly after preparation. Conclusions: The changes in the particle size observed with some drugs suggest that they may cause changes in the lipid particle size during administration and, therefore, those antibiotics agents should not be administered concurrently with fat emulsion.

OBSIDIAN PRODUCTION AND CHANGING CONSUMPTION IN THE LAKE PATZCUARO BASIN, MICHOACAN, MEXICO

Many Tarascan settlements surrounded Lake Patzcuaro in Michoacan, Mexico, during the Late Postclassic period. A hierarchy of settlements existed from the capital of Tzintzuntzan to secondary administration sites and small tributary communities. Obsidian artifacts from the large site, Erongaricuaro, have been studied by the author. Analysis of the obsidian from this site highlighted particular patterns in the production and consumption of prismatic blades and large scrapers. Data from another site, Urichu, was collected and analyzed more recently. Urichu was a tributary center to Erongaricuaro during the Tarascan empire. Local and state elites inhabited both sites, and analysis of obsidian manufacture indicates that the sites may have had different functions. Obsidian from the sites also varies by source location. This too may indicate site function and the changing sociopolitical organization of obsidian production and use throughout the Tarascan empire.