Adjuvants, Anesthesia

The aim of this systematic review is to assess the effectiveness of acupuncture as an adjunctive analgesic method to standard anaesthetic procedures for surgery and to determine whether acupuncture has any analgesic-sparing effect. Electronic literature searches for randomised clinical trials (RCTs) of acupuncture during surgery were performed in seven electronic databases. No language restrictions were imposed. All included studies were rated according to their methodological quality and validity. As the studies were clinically heterogeneous, no meta-analyses were performed.

We studied the effect of DBP on thiopentone hypnosis in 580 patients aged 20 to 30 and 560 patients aged 40 to 50. The hypnotic effect of thiopentone was evaluated after 5, 15, 30, 45 and 60 minutes from intravenous administration of 0.05 mg.kg-1 of DBP by using dose-effect curves to identify the ED50 dose. The ED50 value of thiopentone decreased up to 15 minutes after DBP (about 1.1 mg.kg-1 in both age groups) and increased after 30, 45 and 60 minutes, the increase being higher in the patients aged 40 to 50.

The effect of tizanidine given as a premedication on perioperative hemodynamics (mean blood pressure, heart rate), sedation, hypnosis and midazolam requirements for induction were assessed in 68 patients scheduled for elective surgery under general anesthesia. Patients were assigned to three groups. Group 1 was premedicated 90 min prior to induction with tizanidine 4 mg po (n = 28); group 2 was premedicated with tizanidine 2 mg po (n = 12); group 3 received no premedication (n = 28).

We investigated the effect of adenosine on hypnosis induced by thiopentone, propofol and midazolam in mice. The onset and duration of hypnosis were determined by the loss of righting reflex. Adenosine and 2-chloroadenosine caused a significant shortening of onset of sleep-time and prolongation of duration of sleep-time in all groups (p < 0.05). Dipyridamole administration before combined intravenous anaesthetic-adenosine or intravenous anaesthetic-2-chloroadenosine administration produced similar effects to adenosine (p < 0.05).

We investigated the effect of a small dose of midazolam, ketamine, droperidol or lidocaine on the propofol dose required for hypnosis during induction of general anaesthesia. These drugs were randomly administered to 100 patients about to undergo scheduled surgery. Propofol was then infused at a rate of 250 microg kg-1 min-1 and the hypnotic dose to produce hypnosis was evaluated.

In this prospective study, we evaluated the combined influence of age and premedication on propofol requirements for the induction of anesthesia and their hemodynamic effects using a target-controlled infusion. We studied 180 patients separated into three age groups: 20-39 yr, 40-59 yr, and more than 59 yr. In each age group, patients were randomly allocated to receive either no premedication (n = 20), fentanyl (2 microg/kg) (n = 20), or midazolam (0.03 mg/kg) plus fentanyl (2 microg/kg) (n = 20).

Closed-loop control of propofol delivery was instituted in three patients who received a propofol infusion as part of: (Case 1) general "balanced" anesthesia, (Case 2) total intravenous anesthesia, and (Case 3) monitored anesthesia care. The bispectral index was the input variable used in a proportioned, integral and differential controller to determine the infusion rate of propofol required to maintain a stable level of hypnosis (Cases 1 and 2) or sedation (Case 3).

STUDY OBJECTIVE: To evaluate the effect of a small dose of midazolam (10 microg kg(-1)) on induction and emergence during short-term propofol anesthesia and to investigate the effects of subsequent administration of flumazenil. DESIGN: Double-blinded, prospective, randomized study. SETTING: Operating room of a medical college hospital. PATIENTS: 30 male ASA physical status I and II patients (ages 51 to 75) scheduled for minor surgery under spinal anesthesia.