Remifentanil provides an increased proportion of time under light sedation than fentanyl when combined with dexmedetomidine for mechanical ventilation.

OBJECTIVE: To compare the effects of remifentanil versus fentanyl during light sedation with dexmedetomidine in adults receiving mechanical ventilation (MV) in the intensive care unit. METHODS: In this retrospective cohort study, we compared the use of remifentanil versus fentanyl in adults receiving MV with dexmedetomidine sedation. The primary outcome was the proportion of time under light sedation (Richmond Agitation-Sedation Scale score between -1 and 0) during MV. RESULTS: We included 94 patients and classified 58 into the remifentanil group and 36 into the fentanyl group. The mean proportion of time under light sedation during MV was 66.6% ± 18.5% in the remifentanil group and 39.9% ± 27.3% in the fentanyl group. In the multivariate analysis with control for confounding factors, patients in the remifentanil group showed a significantly higher proportion of time under light sedation than patients in the fentanyl group (mean difference: 24.3 percentage points; 95% confidence interval: 12.9-35.8). CONCLUSIONS: Remifentanil use might increase the proportion of time under light sedation in patients receiving MV compared with fentanyl administration.

Determination of cellular aminopropyltransferase activity using precolumn fluorescent etheno-derivatization with high-performance liquid chromatography.

Polyamines such as spermidine (Spd) and spermine (Spm), produced by aminopropyltransferase (Apt), play roles in cell growth and differentiation. A sensitive and simple fluorometric high-performance liquid chromatographic determination for Apt activity of spermidine synthase (Spdsyn) and spermine synthase (Spmsyn) was developed in order to examine cellular functions of polyamine synthesis. The derivatization procedure for methylthioadenosine (MTA) produced from decarboxylated S-adenosylmethionine by Apt was the reaction with 2-chloroacetaldehyde to give fluorescent 1, N(6)-etheno methylthioadenosine. The reaction conditions for derivatization were optimized. A calibration curve was established, ranging from 0.01 to 25 pmol. Quantification of derivatized MTA was confirmed to be identical to Spd or Spm production. The developed method determined Spdsyn and Spmsyn activities in HepG2 cells treated with oleic acid as a cellular lipid accumulation model.