Anaesthesia
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Randomized Controlled Trial Comparative Study Clinical Trial
The effects of pethidine, fentanyl and lignocaine on postanaesthetic shivering.
Pethidine is reported to be more effective than equi-analgesic doses of other opioids as an inhibitor of postanaesthetic shivering. The aim of this study was to verify whether this action resulted from a local anaesthetic effect of pethidine or from inadequate fentanyl dosage in previous studies. We studied 52 ASA 1 or 2 patients. ⋯ The mean (SD) core temperature in the pethidine group was slightly lower than that in the fentanyl group (35.1 (0.6) and 35.9 (0.5)) when the patients stopped shivering. Furthermore, shivering restarted in 6/10 patients in the fentanyl group after 15 min compared with 1/12 in the pethidine group. Our results show that fentanyl (1.7 micrograms.kg-1) can inhibit postanaesthetic shivering but this effect is less pronounced and of shorter duration than with pethidine (0.85 mg.kg-1).
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Randomized Controlled Trial Clinical Trial
The effect of midazolam premedication on implicit memory activation during alfentanil-nitrous oxide anaesthesia.
Eighty-three patients were given midazolam 0.1 mg.kg-1 by intramuscular injection as premedication before general anaesthesia with alfentanil-nitrous oxide. During anaesthesia patients were presented (through headphones) with either statements about common facts of some years ago (group A) (n = 43) or new verbal associations, e.g. names of fictitious, nonfamous people (group B) (n = 40). ⋯ In this study we found no explicit or implicit memory for the auditory information presented during anaesthesia. Midazolam premedication can prevent implicit memory activation during alfentanil-nitrous oxide anaesthesia.
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Randomized Controlled Trial Clinical Trial
The effects of 2% lignocaine gel on incidence of retching with the use of the laryngeal mask airway.
This randomised, single-blind study investigated the incidence of retching during emergence from general anaesthesia with a laryngeal mask airway in place. Eighty four patients, ASA grade 1 and 2, aged 15 to 60 years, were randomly divided into two groups. Each patient received fentanyl 1 microgram.kg-1 and propofol 2 mg.kg-1 for induction. ⋯ The patients were allowed to wake up at the end of surgery with the laryngeal mask airway in place while a blinded observer observed for retching. The age, sex, weight and duration of surgery were similar in both groups. The test group had a significantly lower incidence of retching on emergence from general anaesthesia with the laryngeal mask airway in place (p < 0.005, Chi-squared test).
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Randomized Controlled Trial Clinical Trial
Sedation with intravenous infusions of propofol or thiopentone. Effects on pain perception.
The aim of this study was to investigate pain perception during thiopentone or propofol infusions for sedation. Thirty ASA 1 or 2 patients received a two step infusion of either thiopentone (step 1: 1.25 mg.kg-1 followed by 2.5 mg.kg-1.h-1; step 2: 1.25 mg.kg-1 and 12.5 mg.kg-1.h-1; n = 15) or propofol (step 1: 0.5 mg.kg-1, 1 mg.kg-1.h-1; step 2: 0.5 mg.kg-1, 5 mg.kg-1.h-1; n = 15) for sedation. At control and 10 min after the start of each infusion dosage, reaction times and thermal pain detection thresholds were determined. We found no clinically or statistically significant depression of thermal pain detection thresholds during propofol or thiopentone infusions and these are, therefore, unlikely to be associated with clinically relevant hyperalgesia.
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Randomized Controlled Trial Clinical Trial
Lignocaine test dose to detect intravenous injection.
The accidental intravascular injection of bupivacaine or etidocaine epidurally has resulted in several maternal deaths. To be effective, a test dose must allow detection of intravenous catheter placement and prevent accidental intravenous injection. This study was designed to determine the dose of lignocaine required for this purpose. ⋯ At 1 min intervals the patients were asked about subjective symptoms produced by this 'test dose'. In group 2 only 50% of patients reported a positive test dose, whereas in the patients of group 3, a significantly greater percentage (95%) had a positive test dose (p < 0.01). This suggests that the use of 1 mg.kg-1 lignocaine as a test dose would result in a significantly higher sensitivity for detecting intravascular injection than the use of 0.5 mg.kg-1.