An electroencephalographic comparison of effects of propofol and methohexital (original) (raw)
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Acta Anaesthesiologica Scandinavica, 1990
Anesthesia and recovery during the first hour after propofol and methohexital anesthesia for termination of pregnancy, lasting about 12 min, were compared, the latter in a double-blind manner by means of psychomotor tests (coin counting and continuous auditory reaction time). Muscle movements and hiccups were seen significantly more frequently during methohexital inductions. No differences were seen regarding pain at the site of injection or apnea between the groups. At 15 min after the last dose of anesthetic, recovery after methohexital was ahead of that after propofol, but after 1 h, psychomotor performance was better in the propofol group. Side-effects during recovery were few, and incidences did not differ significantly. Although the difference in reaction time test was significant, it was hardly large enough to be of any clinical importance. Both drugs are useful for brief outpatient anesthesia, but smoother induction gives propofol an edge over methohexital.
Comparison of induction and recovery profiles of intravenous propofol and thiopentone anesthesia
International Journal of Medical Science and Public Health, 2016
Background: In day care anesthesia, postoperative recovery is of importance. In addition to economical gains, the inconvenience, which is avoided, and the time gained by the patient to resume daily life are notable. Objective: To compare the induction and recovery profiles of the propofol with thiopentone in day care patients. Materials and Methods: A prospective, randomized, patient-blinded, parallel-group, noncrossover trial carried out in Department of Anesthesia of our teaching hospital. Hundred females of ASA group I and II aged between 20 and 45 years, scheduled for minor gynecological procedures, were randomly allocated to two groups that received either propofol or thiopentone. Induction time was measured. The occurrences of cough/hiccup, pain, apneic episodes, twitching, or movements during induction and maintenance were recorded. Blood pressure, SpO 2 , and pulse rate were recorded at intervals. During recovery, waking time, talking time, sitting time, and standing time were observed. Psychomotor recovery was studied by the performance of aiming test and dexterity test. The patients were observed for complaints of any adverse effects up to 4 h of recovery. Independent statistician applied unpaired t-test, repeated-measures ANOVA, and Fischer's exact test, according to requirements, using GraphPad Prism, 5.01. Result: In this study, the mean induction dose of propofol was 2.31 ± 0.01 mg/kg and thiopentone was 4.55 ± 0.02 mg/kg. The mean induction time was 30.16 ± 1.23 and 29.56 ± 1.16 min, respectively. Apnea was 50% with propofol induction, and only 30% with thiopentone. Involuntary movements were more in propofol group, whereas hiccup/cough was more with thiopentone. There was significant fall in blood pressures in propofol group during induction. Recovery was faster with propofol, than thiopentone. Postoperative aiming scores and dexterity time in thiopentone group were significantly low than those in the propofol group. Comparison with baseline scores, at first and second hours, showed significantly low scores in thiopentone group, but at 4 h, the difference was not statistically significant in either group. Adverse effects were more common with thiopentone. Conclusion: The recovery characteristics of propofol are superior to those of thiopentone. The return of psychomotor performance and cognitive functions are more rapid in propofol group.
A comparison of induction of anaesthesia using two different propofol preparations
Southern African Journal of Anaesthesia and Analgesia
Background: Investigators have reported inter-patient variability with regard to propofol dosage for induction of anesthesia, since early dose finding studies. With the arrival of generic formulations of propofol, questions have arisen regarding further variability in dose requirements. Various studies have confirmed that generic propofol preparations are pharmacokinetically and pharmacodynamically equivalent to Diprivan ®. Nevertheless a number of practitioners are under the impression that certain generic propofol preparations require greater doses for induction of anaesthesia than does Diprivan ®. Methods: 20 female patients of ASA status I-II, between the ages of 18-55 years, scheduled for routine surgery were randomly allocated to two groups to undergo induction of anaesthesia using two different propofol formulations; Diprivan ® and Propofol 1% Fresenius ®. Either preparation was administered using a target-controlled infusion of propofol (STEL-TCI) targeting the plasma (central) compartment at a concentration of 6 μg.ml-1 , employing the pharmacokinetic parameters of Marsh et al. A processed EEG (bispectral index) was continuously recorded. Loss of consciousness (LOC) was regarded as the moment at which the patient could not keep her eyes open and was confirmed by the absence of an eyelash reflex. At this point propofol administration was discontinued and data were recorded for a further two minutes, before administering an appropriate opioid and/or nitrous oxide/volatile agent and/or muscle relaxant to maintain anaesthesia. Time to LOC after start of propofol administration, and the dose of propofol administered during induction were annotated. Results: There were no demographic differences between the groups. There were no differences between the groups with regard to the mean dose for LOC, time to LOC and to the mean BIS values obtained at the following stages: awake, at LOC, at 1 and 2 minutes after LOC as well as the lowest recorded value. Conclusions: Our results confirm that the two propofol formulations that we studied, are pharmacologically equivalent with regard to induction of anaesthesia. Other mechanisms can explain the variability in clinical response to bolus administration of propofol. The most important is the recirculatory or "front-end" kinetics of propofol in which cardiac output plays a major role, as well as the rate of drug administration. Emulsion degradation can also influence dose-response and in this regard it should be noted that the addition of foreign substances such as lignocaine, can result in rapid deterioration of the soyabean emulsion.
Southern African Journal of Anaesthesia and Analgesia, 2008
Background: Investigators have reported inter-patient variability with regard to propofol dosage for induction of anesthesia, since early dose finding studies. With the arrival of generic formulations of propofol, questions have arisen regarding further variability in dose requirements. Various studies have confirmed that generic propofol preparations are pharmacokinetically and pharmacodynamically equivalent to Diprivan ® . Nevertheless a number of practitioners are under the impression that certain generic propofol preparations require greater doses for induction of anaesthesia than does Diprivan ® .
An Update on Clinical Concepts of Propofol
Journal of Evolution of medical and Dental Sciences, 2014
Propofol is an intravenous anaesthetic agent. Used as an induction agent it has replaced sodium thiopentone to a large extent. Apart from induction Propofol is used for maintenance of anaesthesia, intravenous sedation and as infusion in mechanically ventilated patients. Its faster and clear recovery has made it a drug of choice in day care cases. Propofol is cardiorespiratory depressant drug.It also lowers intracranial pressure and the laryngeal-pharyngeal reflexes. The properties of Propofol has made it a widely accepted anaesthetic agent. Wide application and easy availability has put the person using it at the risk of drug abuse. This article has focused on the
Propofol for Monitored Anesthesia Care
Anesthesiology, 2000
Background Hypoxia has a dual effect on ventilation: an initial period of hyperventilation, the acute hypoxic response, is followed after 3-5 min by a slow decline, the hypoxic ventilatory decline. Because of hypoxic ventilatory decline, subsequent acute hypoxic responses are depressed. In this study, the influence of a sedative concentration of propofol on ventilation was studied if hypoxia was sustained and intermittent. Methods Ten healthy young male volunteers performed two hypoxic tests without and with a target controlled infusion of propofol. The sustained hypoxic test consisted of 15 min of isocapnic hypoxia followed by 2 min of normoxia and 3 min of hypoxia. The test of hypoxic pulses involved six subsequent exposures to 3 min hypoxia followed by 2 min of normoxia. The bispectral index of the electroencephalogram was measured to obtain an objective measure of sedation. Results Blood propofol concentrations varied among subjects but were stable over time (mean blood concentr...
Propofol and Methohexital as Anesthetic Agents for Electroconvulsive Therapy
Journal of Ect, 2007
Background: Propofol is often used as an anesthetic agent for electroconvulsive therapy (ECT). Whether the relatively short seizure duration, resulting from the medication, deteriorates the seizure quality and therapeutic outcomes, or whether propofol might be associated with small but significant post-ECT cognitive impairments, is still a subject of controversy. The purpose of our study was to test these hypotheses in comparison with methohexital. Materials and Methods: In a double-blind, controlled study, 50 patients with severe major depression who were to be treated with ECT were randomly assigned to anesthesia with propofol (120.9 T 50.0 mg) or methohexital (83 T 26.3 mg) and were observed for 2 months. The 2 drugs were compared on the basis of electroencephalography-registered seizure duration, mean blood pressure, as well as pulse frequency, seizure efficacy index, and postictal suppression. Systolic and diastolic blood pressure, and seizure duration and quality were recorded consecutively during ECT treatments. Changes in depressive symptoms and cognitive functions were measured at 5 time points, pre-ECT, after the third to fifth ECT, post-ECT treatment, and at a follow-up examination 2 and 8 weeks after the last ECT treatment. Results: Patients on propofol showed a significantly lower increase in blood pressure post-ECT (P G 0.001), their seizure duration was comparable to patients on methohexital (P = 0.072), and seizure quality was significantly superior, as was measured by the Postictal Suppression Index (P = 0.020), and comparable to the methohexital group as measured by the Seizure Efficacy Index (P = 0.160). The improvement of depressive symptoms and the improvement in cognitive functions were similar in both groups (with the exception of the results from 2 cognition tests). Conclusions: Propofol, as compared with methohexital, results in a more moderate increase in blood pressure and shorter seizure duration. The seizure quality did not differ significantly between the 2 groups. We detected a tendency toward improved cognitive performance after anesthesia with propofol as compared with methohexital, but with statistical significance in only 2 cognition trials. Therefore, propofol is a safe and efficacious anesthetic for ECT treatment.