Methohexital Group Research Articles

Comparison of Bolus Dosing of Methohexital and Propofol in Elective DirectCurrent Cardioversion.

Background Methohexital and propofol can both be used as sedation for direct current cardioversion (DCCV). However, there are limited data comparing these medications in this setting. We hypothesized that patients receiving methohexital for elective DCCV would be sedated more quickly, recover from sedation faster, and experience less adverse effects. Methods and Results This was a prospective, blinded randomized controlled trial conducted at a single academic medical center. Eligible participants were randomly assigned to receive either methohexital (0.5 mg/kg) or propofol (0.8 mg/kg) as a bolus for elective DCCV. The times from bolus of the medication to achieving a Ramsay Sedation Scale score of 5 to 6, first shock, eyes opening on command, and when the patient could state their age and name were obtained. The need for additional medication dosing, airway intervention, vital signs, and medication side effects were also recorded. Seventy patients who were randomized to receive methohexital (n=37) or propofol (n=33) were included for analysis. The average doses of methohexital and propofol were 0.51 mg/kg and 0.84 mg/kg, respectively. There were no significant differences between methohexital and propofol in the time from end of injection to loss of conscious (1.4±1.8 versus 1.1±0.5 minutes; P=0.33) or the time to first shock (1.7±1.9 versus 1.4±0.5 minutes; P=0.31). Time intervals were significantly lower for methohexital compared with propofol in the time to eyes opening on command (5.1±2.5 versus 7.8±3.7 minutes; P=0.0005) as well as at the time to the ability to answer simple questions of age and name (6.0±2.6 versus 8.6±4.0 minutes; P=0.001). The methohexital group experienced less hypotension (8.1% versus 42.4%; P<0.001) and less hypoxemia (0.0% versus 15.2%; P=0.005), had lower need for jaw thrust/chin lift (16.2% versus 42.4%; P=0.015), and had less pain on injection compared with propofol using the visual analog scale (7.2±9.7 versus 22.4±28.1; P=0.003). Conclusions In this model of fixed bolus dosing, methohexital was associated with faster recovery, more stable hemodynamics, and less hypoxemia after elective DCCV compared with propofol. It can be considered as a preferred agent for sedation for DCCV. Registration URL: https://www.clinicaltrials.gov/ct; Unique identifier: NCT04187196.

A Safety Comparison of Single-Agent Methohexital, Ketamine, or Propofol for Musculoskeletal Procedural Sedation in the Emergency Department

BackgroundThe use of sedative and analgesic agents is required for procedural sedation in the emergency department (ED). Agents such as ketamine and propofol are commonly used for procedural sedation. This is likely due to clinical experience with these agents, as well as optimal pharmacologic properties when used in combination with one another. Methohexital, a barbiturate, is less frequently used due to concerns for adverse events associated with this drug class. ObjectiveThe objective of this study is to evaluate the safety of methohexital in comparison with ketamine and propofol when used for procedural sedation in musculoskeletal procedures. MethodsA retrospective chart review was conducted to evaluate adult ED patients who received ketamine, propofol, or methohexital for procedural sedation from January 1, 2014 to June 30, 2020. ResultsOverall, a total of 43 procedures were included in the study. Procedures included shoulder relocation, elbow relocation, hip relocation, ankle reduction, radius/ulnar reduction, mandibular relocation, patellar relocation, and wrist reduction. There was a 90.6% overall procedural success rate, which was similar between groups. Overall adverse events occurred in 34.8% of patients. Respiratory depression occurred in 9.3% of patients. No incidence of respiratory depression was observed in the methohexital group, compared with 2 patients receiving ketamine and 4 receiving propofol (p = 0.44). ConclusionMethohexital is a safe and effective option for procedural sedation for musculoskeletal procedures in the ED when compared with ketamine and propofol.

Advantages of methohexital over amobarbital in determining hemispheric language and memory lateralization in the Wada test – A retrospective study

ObjectiveDue to supply shortage, amobarbital, the traditional anesthetic agent in Wada testing, was replaced by methohexital in many epilepsy centers. This study aimed to compare the two barbiturates to identify possible advantages or disadvantages of methohexital as compared to amobarbital with regard to the adequacy of language and memory testing during the Wada test. MethodsData from 75 patients with temporal lobe epilepsy who underwent bilateral Wada tests using either amobarbital (n = 53) or methohexital (n = 22) as part of presurgical work-up were analyzed retrospectively. The two subgroups were compared regarding hemispheric language and memory lateralization results and Wada testing characteristics, and the adequacy of language and memory testing was assessed. ResultsWe observed shorter durations of motor-, speech-, and EEG recovery after each injection in patients receiving methohexital compared to amobarbital. In addition, significantly more items could be presented during effective hemispheric inactivation in the methohexital group. Moreover, significant correlations of Wada memory scores with standard neuropsychological memory test scores could be found in the methohexital group. SignificanceOur findings confirm that methohexital is not only equally suitable for Wada testing but has several advantages over amobarbital. Wada testing can be performed more efficiently and under more constant hemispheric inactivation using methohexital. Furthermore, the adequacy of language and memory testing during the Wada test might be affected by the anesthetic agent used.

A Comparison of Etomidate, Ketamine, and Methohexital in Emergency Department Rapid Sequence Intubation.

Rapid sequence intubation (RSI) is routinely used for emergent airway management in the emergency department (ED). It involves the use of induction, and paralytic agents help facilitate endotracheal tube placement. In response to a previous national drug shortage resulting in the use of alternative induction agents for RSI, we describe the effectiveness and safety of ED RSI with ketamine or methohexital compared with etomidate. We conducted a retrospective, single-center observational study from March 1-August 31, 2012 describing RSI with etomidate, ketamine, and methohexital. All adult patients undergoing RSI in the ED who received etomidate prior to its shortage and methohexital or ketamine during the shortage were included. The study included 47, 9, and 26 patients in the etomidate, ketamine, and methohexital groups, respectively. Successful intubation on the first attempt occurred in 74.5%, 55.6%, and 73.1% of the etomidate, ketamine, and methohexital groups, respectively. The mean number of intubation attempts and time to intubation seemed to be similar in all groups. At least three intubation attempts were required in 22.2% and 7.7% of the ketamine and methohexital groups, respectively, compared with none in the etomidate group. Two aspirations were observed in the etomidate group. Methohexital and etomidate had similar rates of successful intubation on the first attempt and seem to be more effective than ketamine. Etomidate may reduce the need for three or more intubation attempts. Larger, prospective studies are needed to determine if ketamine or methohexital are more effective than etomidate for RSI.

Ketamine Anesthesia Does Not Improve Depression Scores in Electroconvulsive Therapy: A Randomized Clinical Trial.

Although interest in ketamine use during electroconvulsive therapy (ECT) has increased, studies have been equivocal with regard to its efficacy. The aims of this clinical trial were to evaluate ketamine's antidepressive effects in ECT as a primary anesthetic, determine ketamine's tolerability when compared with standard anesthesia, and determine if plasma brain-derived neurotrophic factor (BDNF) is necessary for treatment response. Adults meeting criteria for treatment-resistant depression undergoing index course ECT received either methohexital (1 to 2 mg/kg) or ketamine (1 to 2 mg/kg) anesthesia in this dual-arm double-blinded randomized clinical trial (NCT02752724). The primary outcome of this study is change in depression questionnaire scores before and after ECT. Seizure data, depression severity using self-reported and clinician-assessed questionnaires, cognitive scoring, and plasma BDNF concentrations were obtained before and after completion of ECT. There were no differences in seizure lengths, hemodynamics, or seizure stimuli between the ketamine (n=23;138 ECTs) and methohexital (n=27;159 ECTs) groups. Depression scores improved similarly after ECT in both groups. In the methohexital group, 15% of patients failed to achieve adequate seizures and were switched to ketamine and 26% were converted to bilateral ECT stimulus, whereas all ketamine patients achieved adequate seizures and only 4% required bilateral stimulus. Plasma BDNF increased after ECT only in the ketamine group. Our data show that ketamine does not significantly improve depression when compared with methohexital as a single induction agent for ECT, increases serum BDNF and does not increase rates of post-ECT agitation. Ketamine use in ECT may have some benefits for some patients that are not captured through standard depression assessment questionnaires alone.

Different regimens of intravenous sedatives or hypnotics for electroconvulsive therapy (ECT) in adult patients with depression.

Depression is a common mental disorder. It affects millions of people worldwide and is considered by the World Health Organization (WHO) to be one of the leading causes of disability. Electroconvulsive therapy (ECT) is a well-established treatment for severe depression. Intravenous anaesthetic medication is used to minimize subjective unpleasantness and adverse side effects of the induced tonic-clonic seizure. The influence of different anaesthetic medications on the successful reduction of depressive symptoms and adverse effects is unclear. This review evaluated the effects of different regimens of intravenous sedatives and hypnotics on anti-depression efficacy, recovery and seizure duration in depressed adults undergoing ECT. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2012, Issue 12); MEDLINE via Ovid SP (from 1966 to 31 December 2012); and EMBASE via Ovid SP (from 1966 to 31 December 2012). We handsearched related journals and applied no language restrictions. We included randomized controlled trials (RCTs) and cross-over trials evaluating the effects of different intravenous sedatives and hypnotics for ECT. We excluded studies and trials using placebo or inhalational anaesthetics and studies that used no anaesthetic. Two review authors independently assessed trial quality and extracted data. When possible, data were pooled and risk ratios (RRs) and mean differences (MDs), each with 95% confidence intervals (CIs), were computed using the Cochrane Review Manager statistical package (RevMan). We included in the review 18 RCTs (599 participants; published between 1994 and 2012). Most of the included trials were at high risk of bias.We analysed the results of studies comparing six different intravenous anaesthetics.Only a few studies comparing propofol with methohexital (four studies) and with thiopental (three studies) could be pooled.No difference was noted in the reduction of depression scores observed in participants treated with propofol compared with methohexital (low-quality evidence). These four studies were not designed to detect differences in depression scores.The duration of electroencephalograph (EEG) and of motor seizures was shorter in the propofol group compared with the methohexital group (low-quality evidence). No difference was seen in EEG seizure duration when propofol was compared with thiopental (low-quality evidence).Time to recovery (following commands) was longer among participants after anaesthesia with thiopental compared with propofol (low-quality evidence).For the remaining comparisons of anaesthetics, only single studies or insufficient data were available. Adverse events were inadequately reported in eligible trials, and none of the included trials reported anaesthesia-related mortality. Most of the included studies were at high risk of bias, and the quality of evidence was generally low. The studies were not designed to detect clinically relevant differences in depression scores. Anaesthetic agents should be chosen on the basis of adverse effect profile, emergence and how these medications affect seizure duration. If it is difficult to elicit an adequately long seizure, methohexital may be superior to propofol (low-quality evidence). If a patient is slow to recover from anaesthesia, propofol may allow a faster time to follow commands than thiopental (low-quality evidence). A factor of clinical concern that was not addressed by any study was adrenal suppression from etomidate. Optimal dosages of intravenous sedatives or hypnotics have not yet been determined.Larger well-designed randomized studies are needed to determine which intravenous anaesthetic medication leads to the greatest improvement in depression scores with minimal adverse effects.

Comparison of methohexital and etomidate as anesthetic agents for electroconvulsive therapy in affective and psychotic disorders

BackgroundECT is a well-established treatment for severe depression. The available data on psychosis are limited, but reliable. Its therapeutic potential relies on the induction of a generalized seizure. Besides other narcotics, methohexital and etomidate are used for general anesthesia in ECT. Since prolonged seizures have been reported following the use of etomidate, it can be deduced that the substances might differ in their anticonvulsant properties, resulting in a lower increase in stimulus intensity during the course of treatment under etomidate. Besides this hypothesis, we aimed to investigate the differential effects of etomidate and methohexital on clinical features, ECT parameters and side effects of the treatment. MethodsWe performed a retrospective analysis of treatment data of patients with affective and psychotic diagnosis who received general anesthesia for ECT either with etomidate or with methohexital. ResultsECT with etomidate and methohexital was equally effective. During the course of therapies the administered electric charge increased significantly and equally in both treatment groups. In the methohexital group, but not in the etomidate group, electroencephalographic seizure duration had a declining trend during the course of therapies. We observed more side effects during and immediately after ECT in the methohexital group than in the etomidate group. LimitationsThe limitations of this study are that the patients received various psychotropic co-medications, which influence ictal parameters differently, and, secondly, the study is based on a retrospective analysis. ConclusionThe results of our analysis suggest that etomidate and methohexital affect ictal parameters to different extents. Longer seizure duration and fewer side effects are in favor of etomidate.

Language assessment in Wada test: Comparison of methohexital and amobarbital

Introduction Methohexital has replaced amobarbital during Wada testing at many centers. The objective of our study was to compare the use of methohexital and amobarbital during Wada testing regarding language and memory lateralization quotients as well as speech arrest times. Methods A chart review of 582 consecutive patients undergoing 1041 Wada-procedures was performed (left = 60, right = 63, bilateral = 459). Language lateralization was calculated based on duration of speech arrest using a laterality index, defined as ( L − R)/( L + R). Memory lateralization was expressed as percentage of retained objects and laterality quotient. Results Language and memory lateralization revealed a similar distribution with amobarbital and methohexital. Speech arrest after left and right-sided injection was significantly longer in the amobarbital group as compared to the methohexital group. Language lateralization did not differ in the two groups. Percentage of retained memory items was higher in the methohexital group and there were fewer presented test items in the methohexital group. Discussion Language and memory testing during the Wada test can successfully be performed with methohexital instead of amobarbital. The shorter half-life of methohexital allows repeated injections and shorter interhemispheric testing intervals, but also shortens the testing window.

Comparison of Methohexital and Propofol Use in Ambulatory Procedures in Oral and Maxillofacial Surgery

Short-acting anesthetic agents, such as propofol and methohexital, are commonly used for ambulatory procedures in the practices of oral and maxillofacial surgeons (OMS). This study compares the safety and anesthetic outcomes of propofol and methohexital. In addition, the study compares the safety and outcomes of these agents when administered either by an OMS who simultaneously provides anesthesia and performs the procedure (anesthetist/surgeon), or by a non-OMS provider of anesthesia (anesthesiologist or certified registered nurse anesthetist; CRNA) whose sole obligation is to provide anesthesia. This is a prospective study of anesthesia techniques used in an office-based ambulatory setting by OMS throughout the United States, in which either propofol or methohexital was used for sedation/anesthesia. The study variables included demographic information, anesthetic agent, adverse outcomes related to anesthesia, operative procedure, and provider of anesthesia. These variables were compared with the patient group that received a benzodiazepine/narcotics regimen for sedation (control group). Bivariate (contingency tables) and multivariate (logistic regression) analyses were conducted. P < or = .05 was considered statistically significant. The study included 47,710 patients who met the inclusion criteria: 26,147 (54.8%) patients were in the propofol group, 15,859 (33.2%) were in the methohexital group, and 5,704 (12.0%) were in the benzodiazepine group. Among all study patients, 333 (0.7%) had an adverse event. The most common complication was nausea and vomiting without aspiration. Of the patients in the propofol group, methohexital group, or benzodiazepine group, 0.4%, 1.1%, and 0.8% had an adverse event, respectively. The higher number of complications among patients in the methohexital group compared with patients in the other 2 groups was statistically significant. Of 26,147 patients in the propofol group, 23,799 (91.0%) received anesthesia from an anesthetist/surgeon (OMS), and 2,368 (9.1%) from an anesthesiologist or nurse anesthetist (non-OMS). A total of 109 patients (0.4%) had an adverse event. The majority of patients who received anesthesia from a non-OMS were in the propofol group (2,368 of 2,404 patients; 98.5%). There was no statistically significant difference in the occurrence of adverse outcomes when comparing patients in the propofol group who received anesthesia from an OMS with those who received anesthesia from a non-OMS (P = .24, bivariate analysis; P = .33, multivariate analysis). There is a statistically significant increase in adverse events related to methohexital compared with propofol or benzodiazepine/narcotics for anesthesia. Propofol appears to have the lowest risk for adverse events. There is no statistically significant difference in the number of adverse outcomes between the administration of propofol for ambulatory surgery by OMS as an anesthetist/surgeon and anesthesiologist/nurse anesthetist. It remains critical that our specialty maintains the highest standards, to provide safe anesthesia and to reduce adverse anesthetic events.

Propofol and Methohexital as Anesthetic Agents for Electroconvulsive Therapy

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. 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 +/- 50.0 mg) or methohexital (83 +/- 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. Patients on propofol showed a significantly lower increase in blood pressure post-ECT (P < 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). 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.

Effects of Propofol and Methohexital on Neutrophil Function in Cardiac Surgical Patients

The aim of the study was to compare the effects of propofol and methohexital on neutrophil leukocyte oxidative burst in cardiac surgical patients. Forty-six patients after weaning from cardiopulmonary bypass either received propofol (n=29) or methohexital (n=17). Oxidative burst was measured before induction of anaesthesia, on admission to intensive care unit (ICU), 6 hours after ICU admission and 24 hours after start of anaesthesia. Neutrophil leukocyte oxidative burst at start of anaesthesia and on ICU admission was 93 +/- 4% and 95 +/- 4% (methohexital) and 95 +/- 5% and 96 +/- 4% (propofol). Oxidative burst decreased at 6 hours of ICU stay and 24 hours after start of anaesthesia in propofol group (79 +/- 16 and 72 +/- 19%, p < 0.05) and methohexital group (83 +/- 14% and 82 +/- 15%, P < 0.05). However, at 24 hours after start of anaesthesia oxidative burst was significantly higher for methohexital (82 +/- 15%) than propofol (72 +/- 19%) (p < 0.05). Neutrophil leukocyte oxidative burst is depressed more by propofol than methohexital 24 hours after induction of anaesthesia. However, there were no differences in the clinical outcome in terms of serum creatinine, serum bilirubin, duration of ventilation, pneumonia and length of ICU stay in the two groups.

Deep sedation with methohexital or thiamylal with midazolam for invasive procedures in children with acute lymphoblastic leukemia.

Pediatric oncology/hematology patients, especially those with acute lymphoblastic leukemia (ALL), often undergo repeated painful invasive procedures. Deep sedation, mandatory for these procedures in young children, can reduce patient anxiety and get their compliance during procedures. This study assessed clinical experience of employing methohexital or thiamylal with midazolam as sedative for elective invasive procedures in children with ALL. Between November 1997 and March 2004, 20 out of 33 ALL children received deep sedation after evaluation, mainly because of relatively young age (mean age 4.60 +/- 2.03 years). A total of 176 procedures were done, with 139 being intrathecal therapy. There were 98 and 78 procedures for the methohexital and thiamylal groups, respectively. The average dosages to complete the procedures were 2.2 +/- 1.2 mg/kg for methohexital and 3.4 +/- 2.1 mg/kg for thiamylal. One out of the 176 procedures was failed due to bradycardia, hypotension and cyanosis, in the methohexital group. Otherwise, no significant adverse events were found. Increased heart rate (HR) during stable blood pressure (BP) was observed in both groups. In conclusion, under careful monitoring and performed by experienced practitioners, the application of methohexital or thiamylal combined with midazolam to achieve deep sedation for invasive procedures in young children with ALL is safe.

Seizure Length and Clinical Outcome in Electroconvulsive Therapy Using Methohexital or Thiopental

Seizure duration is an extensively studied and controversial indicator of treatment quality in electroconvulsive therapy. Previous research comparing the effect of the barbiturate anesthetics methohexital and thiopental on seizure duration has yielded conflicting results. A recent period of unavailability of methohexital in the United States allowed for retrospective comparison of seizure length as well as clinical improvement in treatment using each agent. Retrospective review was made of 837 treatments administered to 97 patients between January 2, 2002, and May 31, 2003, examining anesthetic, seizure duration, and Global Assessment of Functioning (GAF) scores of inpatients at hospital admission and discharge. Analysis of variance of treatments 2-5 showed no significant effect for anesthetic on seizure duration. Analysis on a treatment-by-treatment basis revealed a marginally significant trend toward shorter EEG seizures in the thiopental group at the second treatment (50.5 +/- 23.6 s vs. 61.1 +/- 27.9 s; P = 0.07) and fifth treatment (41.7 +/- 16.9 s vs. 51.8 +/- 24.0 s; P = 0.07). A difference approaching statistical significance revealed shorter convulsion length in the thiopental group at treatment 5 (29.0 +/- 12.3 s vs. 34.8 +/- 12.3 s; P = 0.07). Comparison of GAF score improvement at hospital discharge revealed no significant difference (GAF increase 26.4 +/- 9.4 for methohexital-treated patients vs. 24.8 +/- 12.0 for thiopental-treated patients; t = 1.00, df = 82, P > 0.1). Trends approaching significance in treatments 2 and 5 revealed shorter seizures in the thiopental group. However, data on clinical recovery reveals no greater improvement in the methohexital group. Thus, this study calls further into question the premise that choice of barbiturate anesthetic may affect clinical efficacy.

The Comparative Hemodynamic Effects of Methohexital and Remifentanil in Electroconvulsive Therapy

Remifentanil is a short acting opioid frequently used to supplement general anesthesia for brief procedures. Narcotic agents are known for their ability to blunt autonomic responses to stimuli such as laryngoscopy and intubation and do not alter seizure threshold. We hypothesized that the combination of remifentanil and methohexital for induction would produce favorable suppression of sympathetic response during electroconvulsive therapy (ECT). With Institutional Review Board approval and informed consent, patients were enrolled in a prospective, randomized, double-blind, crossover study of methohexital alone versus remifentanil with an adjuvant of low-dose methohexital. One hundred ten ECT treatments were evaluated and subjects were treated in an alternating fashion with one of two induction protocols: Methohexital alone in an 80-100 mg IV bolus or remifentanil 500 mcg IV bolus combined with methohexital 40 mg IV. Bilateral ECT was performed in standard fashion and systolic blood pressure and heart rate were recorded throughout the procedure. No significant differences were found in baseline hemodynamic values between the two groups. Heart rate was significantly lower in the remifentanil group versus methohexital group at one minute post-induction and just prior to ECT stimulus. Pre-ECT systolic blood pressure was not significantly different between the two groups. Heart rate remained lower in the remifentanil group at all measured timepoints during the treatment and continuously for five minutes after the seizure. Systolic blood pressure was significantly lower at one minute following the end of seizure and five minutes after end of seizure. Remifentanil's short duration of action, favorable side effect profile, potential proconvulsant activity and ability to suppress hemodynamic response make it a potential novel drug for ECT induction.

Thiopentone and methohexital, but not pentobarbitone, reduce early focal cerebral ischemic injury in rats

Although barbiturates are considered to be cerebral protectants, little is known regarding the relative efficacy of different barbiturates to reduce ischemic brain injury. In a model of middle cerebral artery occlusion (MCAo), we compared the relative effects of 1.0 and 0.4 burst-suppression doses of thiopentone, methohexital, and pentobarbitone on cerebral infarct. During isoflurane anesthesia, MCAo was achieved via a temporal craniotomy. Thirty minutes before MCAo the rats were randomized to receive one of the following which was maintained throughout the study. Halothane (n=20)-1.2 MAC halothane, thiopentone (n=20), methohexital (n=20), or pentobarbitone (n=20). The first ten animals in each barbiturate group received the respective barbiturate in a dose sufficient to maintain burst-suppression of the electroencephalogram (3-5 bursts x min(-1)). The subsequent ten animals in each barbiturate group received 40% of the burst-suppression dose. After 180 min of MCAo and 120 min of reperfusion, cerebral injury was assessed. For the burst-suppression animals, injury volume (mm3, mean +/- SD) was less in the thiopentone group (88 +/- 14) than the halothane (133 +/- 17), methohexital (126 +/- 19), or pentobarbitone (130 +/- 17) groups (P <0.05). For 0.4 burst-suppression animals, injury volume was less for the methohexital group (70 +/- 22) than the halothane (124 +/- 24), thiopentone (118 +/- 15), or pentobarbitone (121 +/- 20) groups (P <0.05). These data are inconsistent with the longstanding assumption that electrophysiologically comparable doses of the various classes of barbiturates have equivalent protective efficacy. They in turn suggest that mechanisms other than, or at least in addition to, metabolic suppression may contribute to the protective effect of barbiturates.

Effect of intravenous sedation on the outcome of transvaginal oocyte retrieval: a comparative study of propofol- and methohexital-based techniques

This study retrospectively compares patients who underwent outpatient transvaginal follicle aspiration with either a propofol- or methohexital-based intravenous sedation technique. Data collected from patient charts (n = 212) over a 46-month period were analyzed to determine the effects of each sedation technique on procedure and recovery times, number of retrieved ova, as well as rates of nausea, fertilization, cleavage, pregnancy, and delivery. All patients were included in the study, regardless of age or diagnosis. procedure time was lower in the propofol group (51 t 18 min) than in the methohexital group (61 I 20 min) (p > 0.01). Patients in the methohexital group (139 2 51 min) spent more time in the recovery room than did those in the propofol group (71 ? 34 min) (p > 0.01). The nausea rates were significantly lower in the propofol group compared with the methohexital group (1.9% vs. 14.4%, respectively) (p > 0.02). Fertilization rate in the propofol group was 77.7% and was 62.9% in the methohexital group (p > 0.01). The numbers of retrieved ova and the cleavage rates were similar in both groups. The rate of pregnancy in patients sedated with propofol (46.1%) was higher than the methohexital group (26.9%) (p > 0.02). Delivery rate was 38.5% in the propofol group and 20.6% in the methohexital group (p > 0.02). In summary, propofol intravenous sedation for transvaginal follicle aspiration was associ- ated with an improved outcome. Pregnancy and delivery rates were higher while nausea, an unpleasant side effect, was sharply reduced.

The changing role of monitored anesthesia care in the ambulatory setting.

The changing role of monitored anesthesia care in the ambulatory setting.

Anesthesiology Effect of Intravenous Sedation on the Outcome of Transvaginal Oocyte Retrieval: A Comparative Study of Propofol- and Methohexital-Based Techniques

This study retrospectively compares patients who underwent outpatient transvaginal follicle aspiration with either a propofol- or methohexital-based intravenous sedation technique. Data collected from patient charts (n = 212) over a 46-month period were analyzed to determine the effects of each sedation technique on procedure and recovery times, number of retrieved ova, as well as rates of nausea, fertilization, cleavage, pregnancy, and delivery. All patients were included in the study, regardless of age or diagnosis. Procedure time was lower in the propofol group (51 ± 18 minutes) than in the methohexital group (61 ± 20 minutes) (P < 0.01). Patients in the methohexital group (139 ± 51 minutes) spent more time in the recovery room than did those in the propofol group (71 ± 34 minutes) (P < 0.01). The nausea rates were significantly lower in the propofol group compared with the methohexital group (1.9% vs 14.4%, respectively) (P < 0.02). Fertilization rate in the propofol group was 77.7% and was 62.9% in the methohexital group (P < 0.01). The numbers of retrieved ova and the cleavage rates were similar in both groups. The rate of pregnancy in patients sedated with propofol (46.1%) was higher than the methohexital group (26.9%) (P < 0.02). Delivery rate was 38.5% in the propofol group and 20.6% in the methohexital group (P < 0.02). In summary, propofol intravenous sedation for transvaginal follicle aspiration was associated with an improved outcome. Pregnancy and delivery rates were higher while nausea, an unpleasant side effect, was sharply reduced.

Anesthetic modulation of the cardiovascular response to microlaryngoscopy

The modulating effects of propofol versus methohexital on the cardiovascular response to microlaryngoscopy were studied in 35 patients divided into four equal groups (one patient participated twice). Heart rate (HR), mean arterial blood pressure (MAP, cardiac output (CO; impedance cardiography), leg blood flow (LBF; occlusion plethysmography) and concentrations of arterial catecholamines were measured. After administration of atropine and fentanyl (2 micrograms.kg-1), anesthesia was induced by either an injection of propofol (2.0 mg.kg-1) followed by a low (6 mg.kg-1.h-1; n = 9) or a high (12 mg.kg-1.h-1; n = 9) dose propofol infusion or an injection of methohexital (1.5 mg.kg-1) followed by a low (5 mg.kg-1.h-1; n = 9) or a high (10 mg.kg-1.h-1; n = 9) dose methohexital infusion. The low methohexital infusion dose was insufficient to control MAP, which increased 41% during microlaryngoscopy compared to the awake state. The HR increased in all groups but the increase was most prominent in the low dose methohexital group. There were no statistically significant changes in CO in any group, whereas LBF increased consistently in all groups except in patients anesthetized with the low dose of methohexital. The increases of LBF in the propofol groups were intermediate and not dose dependent. The methohexital low dose group showed increases in norepinephrine levels compared to awake values and in epinephrine levels compared to the other groups. Propofol seems to differ from methohexital in modulation of peripheral vascular tone.(ABSTRACT TRUNCATED AT 250 WORDS)

The anxiolytic effects of intravenous sedation using midazolam alone or in multiple drug techniques

This study examines four drug combinations (midazolam, midazolam-midazolam, fentanyl-midazolam, and fentanyl-midazolam-methohexital) in a placebo-controlled double-blind clinical trial of intravenous sedation. It tests the hypothesis that there is no difference between the anxiolytic effect of the four combinations when compared with a saline placebo. Subjects were 207 midly anxious young adults having their third molars removed. Congnitive measures of anxiety increased from preoperative levels in the placebo and both midazolam groups ( P < .05). The anxiety response remained the same in the fentanyl-midazolam and fentanyl-midazolam-methohexital groups ( P > .05). The level of successful anxiolysis ranged from 24% in the placebo group to 74% in the barbiturate group. Using the log likelihood method, comparisons suggest that the drug groups (from midazolam alone to the methohexital combination) have increasingly positive anxiolytic effects even when controlling for the effects of dental fear and intraoperative pain. The fentanyl-midazolam group is 8.1 and the methohexital group is 9.0 times more likely to have had a favorable outcome than the placebo group. Additional analyses of behavioral measures of anxiety yielded parallel results. Global evaluations after surgery were related to the success of anxiolysis for subjects in the active drug conditions ( P < .05).