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Sole use of phenobarbital use for control of AWS may be a safe alternative to benzodiazepines. Further study is needed to correlate phenobarbital serum levels with clinical control of AWS.

Excited-state absorption spectroscopy and ionization threshold measurements for coumarin 314 (C314) adsorbed to the surface of NaCl aerosols characterize the chemical environment of the particle surface as a function of relative humidity (RH). An atmospheric pressure flow of aerosol passes through an ionization cell where two-photon laser ionization of the adsorbed molecules produces a net charge on the particle. Monitoring this charge as a function of the laser wavelength produces either the absorption spectrum of the S(1) <-- S(0) transition or the ionization threshold. The wavelength of maximum absorption for the S(1) excited-state shifts from 448 nm for RH < 5% to 441 nm for RH = 60%, indicating that adsorbed water decreases the polarity of the surface. Similarly, the ionization threshold increases from 5.10 to 5.27 eV over a similar range of RH. The decrease in polarity is attributable to changes in the local electric field experienced by C314, which is on the order of 1 x 10(7) V/cm, and is correlated with changes in the surface topography. Using a continuum model, we estimate the contributions to the measured thresholds of the polarization response of the surface ions and the electric field and calculate an effective dielectric constant for the adsorbed water film. For a multilayer water coverage (RH = 65%), the effective dielectric constant is approximately 2.4. These results demonstrate that the changes in surface topography with adsorbed water are as important as direct water-solute interactions in determining the solvent character of the surface.

Background: Polymyxin B’s package insert recommends renal adjustment. Contemporary studies suggest it does not require renal adjustment. Objective: To determine whether time to acute kidney injury (AKI) differs between renally adjusted and nonadjusted intravenous (IV) polymyxin B. Methods: This retrospective chart review compared time to AKI after renally adjusted and nonadjusted IV polymyxin B administration. It included patients who were 18 years or older, received IV polymyxin B, and had creatinine clearance below 80 mL/min, and excluded ones who had AKI, received renal replacement therapy, or were pregnant. Results: Fifty-four patients were included. There was not any statistical association between dosing type and time to AKI ( P = .13). Incidence of nephrotoxicity, mortality, and length of stay (LOS) were higher in the renally adjusted arm (21.7% vs 6.5%, 17.4% vs 6.5%, and 16 vs 14 days, respectively). Four patients received concomitant ascorbic acid; not one developed AKI. Conclusion: A significant association between IV polymyxin B dosing type and time to AKI was not found. Adverse events were higher in the renally adjusted arm. This suggests that nonadjusted IV polymyxin B may be preferred in patients with renal impairment. Ascorbic acid may mitigate IV polymyxin B's nephrotoxic potential. Further studies are needed to corroborate these findings.

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