European journal of anaesthesiology
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparison of the effects of topical lignocaine spray applied before or after induction of anaesthesia on the pressor response to direct laryngoscopy and intubation.
In an attempt to attenuate the cardiovascular pressor response to laryngoscopy and intubation, 30 patients presenting for routine ophthalmic surgery were studied and were randomly allocated into two groups: group A (n = 15) received direct laryngeal/tracheal lignocaine spray immediately before intubation; and group B (n = 15) received orolaryngeal lignocaine spray before the induction of anaesthesia. In both groups, general anaesthesia was induced with thiopentone 3-5 mg kg-1, followed by atracurium 0.6 mg kg-1 to facilitate tracheal intubation. ⋯ In addition, the plasma lignocaine concentrations remained well below the toxic range in both groups. It was concluded that topical lignocaine administration as an orolaryngeal spray before the induction of anaesthesia is effective in reducing but not abolishing the pressor response to laryngoscopy and endotracheal intubation.
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Randomized Controlled Trial Clinical Trial
Granisetron reduces post-operative vomiting in children: a dose-ranging study.
This study was undertaken to determine the minimum effective dose of granisetron, 5-hydroxytryptamine type 3 receptor antagonist, for the prevention of post-operative vomiting in children undergoing general inhalational anaesthesia for surgery (inguinal hernia and phimosis). In a randomized, double-blind manner, 120 children, ASA physical status I, aged 4-10 years, were assigned to receive placebo (saline) or granisetron at three different doses (20 micrograms kg-1, 40 micrograms kg-1, 100 micrograms kg-1) intravenously immediately after inhalation induction of anaesthesia (n = 30 of each). ⋯ No clinically important adverse events were observed in any of the groups. Our results suggest that granisetron 40 micrograms kg-1 is the minimum effective dose for the prevention of emesis after paediatric surgery, and that increasing its dose to 100 micrograms kg-1 provides no demonstrable benefit.
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Randomized Controlled Trial Clinical Trial
Hypnotic endpoints vs. the bispectral index, 95% spectral edge frequency and median frequency during propofol infusion with or without fentanyl.
Hypnotic endpoints and/or EEG variables, e.g. bispectral index, 95% spectral edge frequency and median frequency, have been studied to monitor anaesthetic (hypnotic) depth during total intravenous anaesthesia. In this study, the relation between the hypnotic endpoints of unresponsiveness to verbal commands, loss of eyelash reflex and body movement response to mechanical nasal membrane stimulation vs. bispectral index, 95% spectral edge frequency and median frequency during propofol anaesthesia with or without fentanyl is presented. Forty-two patients were randomly assigned to receive either propofol infusion, 30 mg kg-1 h-1 (n = 22), or propofol infusion, 30 mg kg-1 h-1 + fentanyl bolus, 2 micrograms kg-1 i.v. (n = 20). ⋯ Doses of propofol for achieving the hypnotic endpoints were significantly lower in the propofol + fentanyl compared with the propofol group. Plasma propofol concentrations at inhibition of nasal body movement response were lower in the propofol + fentanyl compared with the propofol group (9.2 +/- 2.0 micrograms mL-1 vs. 14.1 +/- 4.2 micrograms mL-1). Our results suggest that fentanyl pretreatment potentiates the effects of propofol and achieves the hypnotic endpoints at higher bispectral index values and lower propofol doses and concentrations (measured at inhibition of nasal body movement response).
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Randomized Controlled Trial Clinical Trial
Patient-controlled sedation using propofol: randomized, double-blind dose refinement.
This double-blind, randomized trial compared the onset of sedation with two patient-controlled sedation regimens, allowing a maximum of 16 or 25 mg min-1 propofol. Forty fit young patients presenting for elective surgery were asked to try to put themselves to sleep using the system. Onset times of sedative effect, slurred speech and amnesia were recorded. ⋯ Patients receiving 16 mg min-1 propofol were not reliably sedated within 5 min and took significantly longer to develop slurred speech and amnesia (P < 0.01 for both). We conclude that this maximum infusion rate does not produce amnesia or sedation rapidly enough to be clinically useful. A maximum infusion rate of 25 mg min-1 allowed rapid sedation in all patients without oversedation and may be an acceptable compromise between efficacy and safety.
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Comparative Study
Calculated and measured oxygen consumption in mechanically ventilated surgical patients in the early post-operative period.
Oxygen consumption (VO2) measured by indirect calorimetry (Nellcor-Puritan-Bennett 7250; Carlsbad, CA, USA) has been compared with VO2 calculated by the Fick method in 22 volume-controlled ventilated general surgical patients in the early post-operative period. For 198 pairs of measurements, VO2 Fick and VO2 indirect calorimetry correlated significantly (y = 1.00x - 35.8, P = 0.0001, r = 0.77). VO2 indirect calorimetry was 212 +/- 32 mL min-1 and VO2 Fick was 177 +/- 41 mL min-1 (P = 0.0001). ⋯ VO2 calculated by the Fick method did not accurately predict VO2 measured by indirect calorimetry, and the two methods were not interchangeable. VO2 calculated by the Fick method underestimated VO2 as measured by indirect calorimetry by a systematic quantity that could be attributed, in part, to VO2 of the lung. Indirect calorimetry should be the preferred method for measuring total body VO2 in mechanically ventilated surgical patients.