Anesthesiology
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Randomized Controlled Trial Clinical Trial
Simultaneous measurement and integrated analysis of analgesia and respiration after an intravenous morphine infusion.
To study the influence of morphine on chemical control of breathing relative to the analgesic properties of morphine, the authors quantified morphine-induced analgesia and respiratory depression in a single group of healthy volunteers. Both respiratory and pain measurements were performed over single 24-h time spans. ⋯ Our data indicate that systems involved in morphine-induced analgesia and respiratory depression share important pharmacodynamic characteristics. This suggests similarities in central mu-opioid analgesic and respiratory pathways (e.g., similarities in mu-opioid receptors and G proteins). The clinical implication of this study is that after morphine administration, despite lack of good pain relief, moderate to severe respiratory depression remains possible.
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Randomized Controlled Trial Clinical Trial
Induction speed is not a determinant of propofol pharmacodynamics.
Evidence suggests that the rate at which intravenous anesthetics are infused may influence their plasma-effect site equilibration. The authors used five different rates of propofol administration to test the hypothesis that different sedation endpoints occur at the same effect site propofol concentration, independent of the infusion rate. The authors concurrently evaluated the automated responsiveness monitor (ARM) against other sedation measures and the propofol effect site concentration. ⋯ : Population-based pharmacokinetics, combined with real-time electroencephalographic measures of drug effect, may provide a means to individualize pharmacodynamic modeling during target-controlled drug delivery. ARM seems useful as an automated measure of sedation and may provide the basis for automated monitoring and titration of sedation for a propofol delivery system.
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparison of cisatracurium and vecuronium by infusion in neonates and small infants after congenital heart surgery.
Neonates and infants often require extended periods of mechanical ventilation facilitated by sedation and neuromuscular blockade. ⋯ Our results parallel data from adults demonstrating a markedly shorter recovery of neuromuscular transmission after cisatracurium compared with vecuronium. Decreased clearance of vecuronium and the accumulation of 3-OH vecuronium may contribute to prolonged spontaneous recovery times. Cisatracurium is associated with faster spontaneous recovery of neuromuscular function compared with vecuronium but not with any differences in intermediate outcome measures in neonates and infants.
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Randomized Controlled Trial Comparative Study Clinical Trial
Dexmedetomidine pharmacodynamics: Part II: Crossover comparison of the analgesic effect of dexmedetomidine and remifentanil in healthy volunteers.
Dexmedetomidine is a highly selective alpha2-adrenoceptor agonist used for short-term sedation of mechanically ventilated patients. The analgesic profile of dexmedetomidine has not been fully characterized in humans. ⋯ As expected, dexmedetomidine is not as effective an analgesic as the opioid remifentanil. The difference in the quality of the analgesia with remifentanil may be a reflection of a different mechanism of action or a consequence of the sedative effect of dexmedetomidine.
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Randomized Controlled Trial Clinical Trial
Narcotrend does not adequately detect the transition between awareness and unconsciousness in surgical patients.
The Narcotrend index (MonitorTechnik, Bad Bramstedt, Germany) is a dimensionless number between 0 and 100 that is calculated from the electroencephalogram and inversely correlates with depth of hypnosis. The current study evaluates the capability of the Narcotrend to separate awareness from unconsciousness at the transition between these levels. ⋯ In these challenging data, the Narcotrend did not differentiate between awareness and unconsciousness. In addition, Narcotrend values were not independent from the anesthetic regimen.