Prospective study comparing skin impedance with EEG parameters during the induction of anaesthesia with fentanyl and etomidate

Can changes in skin impedance be used to monitor sedation after midazolam and during recovery from anesthesia?

It has been suggested that sympathetic activity, measured as changes in electrical skin impedance (SI), can be used to assess the adequacy of general anesthesia. Our prospective study investigated if measurements of skin impedance can determine levels of sedation induced by midazolam. Twenty-seven patients scheduled for arthroscopy requiring general anesthesia were served as their own control. These were blinded to the order of injections by telling them that they will be randomly administered a placebo (saline) orsedative agent. A DM 3900 multimeter was used for SI measurements. The degree of sedation was measured using the modified Observer's Assessment of Alertness and Sedation (mOAAS) scale. Resting SI values were noted, and all participants were then administered the placebo followed 5 min later by midazolam 2 mg i.v. Five min after that, patients were administered standard general anesthesia with propofol, oxygen, nitrous oxide 60 %, and isoflurane 1 MAC via a laryngeal mask, and sufentanil 5 - 10 µg. SI significantly increased after administration of midazolam and induction of anesthesia. There were no significant differences between pre-administration (baseline) and placebo and end of surgery and end of anesthesia with closed eyes. There were highly significant differences (p<0.001) between pre-administration vs. midazolam, placebo vs. midazolam, pre-administration vs. induction of anesthesia. We found slight correlation between mOAAS and SI. There were no significant changes between the end of surgery and the end of anesthesia with closed eyes, but SI significantly decreased (p<0.01) after eyes opened.

Sedation and analgesia with fentanyl and etomidate for intrathecal injection in childhood leukemia patients

In this study, we tried to find a safe as well as fast effective treatment for sedation and analgesia for intrathecal injection in childhood leukemia patients, relieving treatment difficulties and pain, increasing the success rate of single intrathecal injection.The patients were divided into the experimental group (fentanyl combined with etomidate) and the control group (lidocaine only) randomly. The experimental group was given fentanyl 1 to 2 μg/kg intravenously first, then etomidate 0.1 to 0.3 mg/kg intravenously after the pipe washed. The patients younger than 1.5 years or who did not achieve satisfied sedative and analgesic situation received an additional time of etomidate (0.1-0.3 mg/kg). The patients were given oxygen at the rate of 4-5 L/min during the whole operation, and the finger pulse oximeter was used simultaneously to detect the changes in heart rate (HR) and blood oxygen saturation (SpO2). The doctors who performed the procedures assessed the quality of sedation and analgesia.In the experimental group, the patients' HR increased slightly after given fentanyl combined with etomidate. The patients' SpO2 was stable. Most patients achieved a good sedative and analgesic state within 1 to 2 minutes, and no case of respiration depression or cardiac arrhythmias occurred during the whole operation. The wake-up time was 55.42 ± 20.62 min. In the control group, the patients were not very cooperative during the intrathecal injection, which made the procedures very difficult.During intrathecal injection, pain obviously reduced and the success rate of single lumbar puncture increased. It is safe and effective to apply fentanyl combined with etomidate for sedation and analgesia.