The effects of midazolam and flumazenil on psychomotor function and alertness in human volunteers

Comparison of dexmedetomidine with midazolam for dental surgery: A systematic review and meta-analysis

INTRODUCTION

Dexmedetomidine and midazolam have become important approaches for the sedation of dental surgery. However, the comparison of these 2 drugs for the sedation of dental surgery has not been well established. We conduct a systematic review and meta-analysis to evaluate the efficacy of dexmedetomidine versus midazolam for dental surgery.

METHODS

PubMed, Embase, and the Cochrane Central Register of Controlled Trials are searched. Randomized controlled trials (RCTs) assessing the influence of dexmedetomidine versus midazolam on dental surgery are included. Two investigators independently have searched articles, extracted data, and assessed the quality of included studies. Meta-analysis is performed using the random-effect model.

RESULTS

Five RCTs and 420 patients are included in the meta-analysis. Compared with midazolam intervention for dental surgery, dexmedetomidine intervention has similar lowest SpO2, lowest heart rate and lowest systolic blood pressure, duration of surgery, and total volume of local anesthetic, but is associated with stable and reduced lowest diastolic blood pressure.

CONCLUSIONS

Similar benefits of dexmedetomidine and midazolam intervention are observed for the sedation of dental surgery in terms of SpO2, heart rate, systolic blood pressure, and the volume of local anesthetic, but dexmedetomidine may result in more stable diastolic blood pressure.

Current trends in intravenous sedative drugs for dental procedures

Anxiety and phobia in dental procedures are common deterrents for patients visiting the dental care unit. For these individuals, procedural sedation may aid in completion of dental treatments. In most cases, the patients are conscious during sedation, thereby allowing spontaneous ventilation. Intravenous sedation (IVS) is widely used during dental treatment to relieve patient anxiety. IVS is the most effective route of administration to achieve this goal, but it requires advanced training, more than that provided during undergraduate education. During IVS, rapid onset, repetitive drug administration, easy titration, and rapid recovery from sedation can be achieved. However, conscious sedation during IVS can result in deep sedation that can cause respiratory and cardiovascular depression. Therefore, the characteristics of intravenous sedatives should be known. The purpose of this review is to discuss the characteristics and usage of intravenous sedatives currently used for dental procedures.

Considerations for submucosal midazolam administration in combination with oral and inhaled medications for sedation of pediatric dental patients

Sedation allows patients to maintain their airway independently and respond appropriately to physical stimulation and verbal command while maintaining a minimum depressed level of consciousness. Drugs commonly used for sedation of pediatric dental patients include a combination of chloral hydrate, hydroxyzine, and nitrous oxide-oxygen. Midazolam is a benzodiazepine and currently one of the most commonly used intravenous sedative agents. It can be easily titrated to provide a wide range of sedation, from conscious sedation to deep sedation, and exhibits a wide safety margin without severe respiratory and circulatory depression. At an appropriate dose, it also decreases patient anxiety and induces amnesia. We found that the submucosal administration of midazolam combined with chloral hydrate provided increased sedative effects and decreased the postoperative vomiting response compared with conventional chloral hydrate administration, with no significant difference in physiological responses. The depth of sedation can be titrated using this technique.

Complications Associated with Intravenous Midazolam Sedation in Anxious Dental Patients

Aim

This prospective study was designed to establish the nature, frequency and sequelae of complications arising in patients receiving dental treatment under intravenous midazolam sedation.

Methods

All patients attending the Sedation Department at Newcastle Dental Hospital for intravenous sedation over a six-month period were audited. A standardised data-collection pro forma was designed in order to collect data relating to the patient, the sedation episode, the dental treatment and any complications arising. The published standard used in this study states that the incidence of complications should be no more than 8%.

Results

Four hundred and one patients were included. The mean dose of midazolam administered was 7.6 mg with a mean titration rate of 0.9 mg/min. Complications were reported in 12 patients (3%), 11 of which were minor and one moderate. All complications were managed successfully within the department with no lasting sequelae. Treatment was completed in 382 (95.7%) patients, with failure to complete treatment in 17 (4.3%) patients due to disinhibition (1), poor cooperation (10), and the sedation wearing off (6).

Conclusion

The standard was met because complications arising were infrequent (3%) and predominantly minor in nature. Complications were managed conservatively and effectively, with all patients being discharged home the same day with no lasting sequelae. The study demonstrates that intravenous midazolam provides a safe sedation technique, suitable for adult dental patients in primary care, when administered by trained personnel on carefully selected patients and in accordance with nationally agreed protocols and guidelines.

Status epilepticus: pathophysiology and management in adults

As in Clark and Prout's classic work, we identify three phases of generalised convulsive status epilepticus, which we call impending, established, and subtle. We review physiological and subcellular changes that might play a part in the transition from single seizures to status epilepticus and in the development of time-dependent pharmacoresistance. We review the principles underlying the treatment of status epilepticus and suggest that prehospital treatment is beneficial, that therapeutic drugs should be used in rapid sequence according to a defined protocol, and that refractory status epilepticus should be treated with general anaesthesia. We comment on our preference for drugs with a short elimination half-life and discuss some therapeutic choices.

A randomised crossover trial of post-operative cognitive and psychomotor recovery from benzodiazepine sedation: effects of reversal with flumazenil over a prolonged recovery period

OBJECTIVE

To study the post-operative cognitive and psychomotor recovery from midazolam conscious sedation, after reversal with the benzodiazepine antagonist flumazenil over a prolonged recovery period.

DESIGN

A prospective, double-blind, randomised, crossover trial.

SETTING

Out-patient Sedation Department, Newcastle Dental Hospital and School

METHOD

Eighteen patients, ASA I or II, received midazolam on two separate occasions to undergo equivalent dental treatment. Following treatment patients were reversed with intravenous flumazenil or saline (placebo) at alternate appointments. Assessment of mood and cognitive function was undertaken using a highly sensitive and specific computerised battery of cognitive tests administered by telephone. Cognitive and psychomotor tests were administered prior to sedation and every hour for 6 hours post reversal.

RESULTS

Results indicated no significant effect of flumazenil on simple reaction time and choice reaction time but did show a trend of reversing the effects of midazolam on numeric working memory and word recognition.

CONCLUSION

The cognitive and psychomotor effects of the sedation were not fully reversed by flumazenil. Cognitive impairments were still present up to 6 hours post-reversal, despite patients appearing clinically more alert. This has important implications for treatment protocols and discharge instructions.

A randomised, controlled trial of cognitive and psychomotor recovery from midazolam sedation following reversal with oral flumazenil

Flumazenil is traditionally administered intravenously to reverse the adverse effects of over sedation with benzodiazepines. The aim of this study was to test postoperative cognitive and psychomotor recovery from midazolam conscious sedation, following reversal with orally administered flumazenil. It was hypothesised that when administered by the oral route, flumazenil may enhance recovery over a prolonged period, thus increasing safety. Eighteen patients requiring intravenous midazolam sedation for dental treatment completed a randomised, double-blind, crossover trial. Following treatment the patients' sedation was reversed using either flumazenil or saline (as placebo), administered orally, on alternate appointments. Assessment of mood and cognitive function were undertaken using ClinPhone.cdr(R), a highly sensitive and specific computerised battery of cognitive tests administered by telephone prior to sedation and every hour for seven hours post reversal. Results indicate that within 20 min of administration, oral flumazenil is capable of partially reversing some cognitive and psychomotor impairments but the attentional and stimulus discrimination effects of midazolam sedation still remain.

An investigation into the acute nootropic effects of Hypericum perforatum L. (St. John's Wort) in healthy human volunteers

Hypericum perforatum L. (St. John's Wort) is a complex herb that has been used for centuries for its putative medicinal properties, and has current therapeutic relevance as a treatment of mild to moderate depression. Recently, two studies in rodents have suggested that hypericum may also have memory-enhancing effects. It has a complex pharmacology, in that acute administration modulates numerous neurotransmitter systems that have previously been observed to either augment or impair a variety of memory processes in humans. This study aimed to examine whether acute administration of standardized hypericum extract could exert a nootropic effect in normal human subjects. The study employed a double-blind, crossover, repeated-measures design. Twelve healthy young subjects completed the Cognitive Drug Research (CDR) memory battery, following administration of placebo, 900 mg and 1800 mg hypericum (Blackmore's Hyperiforte). The findings suggested that hypericum does not have an acute nootropic effect in healthy humans at these doses. However, there was some evidence for an impairing effect on accuracy of numeric working memory and delayed picture recognition at the higher dose. This observed impairment could be due to a sensitivity of these specific tasks to modulation by neurotransmitters that have been noted to have memory-impairing effects (e.g. y-aminobutyric acid (GABA), serotonin).