Midazolam plasma concentration after anesthesia premedication in clinical routine - an observational study : Midazolam plasma concentration after anesthesia premedication

Preoperative Midazolam and Patient-Centered Outcomes of Older Patients: The I-PROMOTE Randomized Clinical Trial

Importance

The effect of oral midazolam premedication on patient satisfaction in older patients undergoing surgery is unclear, despite its widespread use.

Objective

To determine the differences in global perioperative satisfaction in patients with preoperative administration of oral midazolam compared with placebo.

Design, Setting, and Participants

This double-blind, parallel-group, placebo-controlled randomized clinical trial was conducted in 9 German hospitals between October 2017 and May 2019 (last follow-up, June 24, 2019). Eligible patients aged 65 to 80 years who were scheduled for elective inpatient surgery for at least 30 minutes under general anesthesia and with planned extubation were enrolled. Data were analyzed from November 2019 to December 2020.

Interventions

Patients were randomized to receive oral midazolam, 3.75 mg (n = 309), or placebo (n = 307) 30 to 45 minutes prior to anesthesia induction.

Main Outcomes and Measures

The primary outcome was global patient satisfaction evaluated using the self-reported Evaluation du Vécu de l'Anesthésie Generale (EVAN-G) questionnaire on the first postoperative day. Key secondary outcomes included sensitivity and subgroup analyses of the primary outcome, perioperative patient vital data, adverse events, serious complications, and cognitive and functional recovery up to 30 days postoperatively.

Results

Among 616 randomized patients, 607 were included in the primary analysis. Of these, 377 (62.1%) were male, and the mean (SD) age was 71.9 (4.4) years. The mean (SD) global index of patient satisfaction did not differ between the midazolam and placebo groups (69.5 [10.7] vs 69.6 [10.8], respectively; mean difference, -0.2; 95% CI, -1.9 to 1.6; P = .85). Sensitivity (per-protocol population, multiple imputation) and subgroup analyses (anxiety, frailty, sex, and previous surgical experience) did not alter the primary results. Secondary outcomes did not differ, except for a higher proportion of patients with hypertension (systolic blood pressure ≥160 mm Hg) at anesthesia induction in the placebo group.

Conclusion and Relevance

A single low dose of oral midazolam premedication did not alter the global perioperative patient satisfaction of older patients undergoing surgery or that of patients with anxiety. These results may be affected by the low dose of oral midazolam. Further trials-including a wider population with commonplace low-dose intravenous midazolam and plasma level measurements-are needed.

Trial Registration

ClinicalTrials.gov Identifier: NCT03052660.

Selective actions of benzodiazepines at the transmembrane anaesthetic binding sites of the GABAA receptor: In vitro and in vivo studies

BACKGROUND AND PURPOSE

In addition to binding to the classical high-affinity extracellular benzodiazepine binding site of the GABAA receptor, some benzodiazepines occupy transmembrane inter-subunit anaesthetic sites that bind etomidate (β+ /α- sites) or the barbiturate derivative R-mTFD-MPAB (α+ /β- and γ+ /β- sites). We aimed to define the functional effects of these interactions on GABAA receptor activity and animal behaviour.

EXPERIMENTAL APPROACH

With flumazenil blocking classical high-affinity extracellular benzodiazepine site effects, modulation of GABA-activated currents by diazepam, midazolam and flurazepam was measured electrophysiologically in wildtype and M2-15' mutant α1 β3 γ2L GABAA receptors. Zebrafish locomotive activity was also assessed in the presence of each benzodiazepine plus flumazenil.

KEY RESULTS

In the presence of flumazenil, micromolar concentrations of diazepam and midazolam both potentiated and inhibited wildtype GABAA receptor currents. β3 N265M (M2-15' in the β+ /α- sites) and α1 S270I (M2-15' in the α+ /β- site) mutations reduced or abolished potentiation by these drugs. In contrast, the γ2 S280W mutation (M2-15' in the γ+ /β- site) abolished inhibition. Flurazepam plus flumazenil only inhibited wildtype receptor currents, an effect unaltered by M2-15' mutations. In the presence of flumazenil, zebrafish locomotion was enhanced by diazepam at concentrations up to 30 μM and suppressed at 100 μM, suppressed by midazolam and enhanced by flurazepam.

CONCLUSIONS AND IMPLICATIONS

Benzodiazepine binding to transmembrane anaesthetic binding sites of the GABAA receptor can produce positive or negative modulation manifesting as decreases or increases in locomotion, respectively. Selectivity for these sites may contribute to the distinct GABAA receptor and behavioural actions of different benzodiazepines, particularly at high (i.e. anaesthetic) concentrations.

Sedation outcomes for remimazolam, a new benzodiazepine

Remimazolam is a new ultrashort-acting benzodiazepine with fast onset, quick recovery, and few side effects, such as hypotension and respiratory depression. It is expected to be safe and effective for a wide range of patients undergoing intravenous sedation for dental procedures. The aim of this literature review was to evaluate clinical and sedation outcomes for remimazolam, including method of administration, level of sedation at the dose required, and clinical adverse events. An electronic literature search of databases was conducted, and eight articles were selected for inclusion in this review. Onset time from drug administration to optimal sedation level was faster for remimazolam (around 1.5-6.4 min) than for midazolam. Recovery time was significantly shorter for remimazolam than for midazolam and propofol. A study comparing various doses of remimazolam with midazolam found no significant difference in safety. Comparison of a remimazolam group with a propofol group showed that incidences of hypotension (13.0% vs 42.9%, respectively) and respiratory depression (1.1% vs 6.9%, respectively) were significantly lower for remimazolam. Remimazolam appears to be an ideal sedative.

Effects of anesthetic agents on inflammation in Caco-2, HK-2 and HepG2 cells

Anesthetic agents are often used in surgical procedures to relieve pain in patients with traumatic injuries. Several anesthetic agents can cause immunosuppression by suppressing the secretion of immune factors such as cytokines. However, the effects of different anesthetic agents on inflammation are not completely understood. In the present study, three cell lines, Caco-2, HK-2 and HepG2, were treated with five anesthetic agents, including sodium barbiturate, midazolam, etomidate, ketamine and propofol, to investigate the effects of different anesthetic agents on inflammation in in vitro models. The expression levels of inflammatory genes, including NF-κB and its downstream cytokines, were detected via reverse transcription-quantitative PCR. The results indicated that anesthetic agents, including sodium barbiturate, ketamine and propofol, but not midazolam and etomidate, exerted significant inhibitory effects on NF-κB expression in the three different cell lines. Sodium barbiturate, ketamine and propofol also decreased the expression levels of the NF-κB downstream cytokines, including IL-1β and IL-18. Moreover, sodium barbiturate, ketamine and propofol reduced the effect of TNF-α on inflammatory activity in the three cell lines. The results of the present study may provide novel insight into the effects of anesthetic agents on inflammation and may aid with selecting the most appropriate anesthetic agent in surgical procedures.

Remimazolam tosilate in upper gastrointestinal endoscopy: A multicenter, randomized, non-inferiority, phase III trial

BACKGROUND AND AIM

Remimazolam tosilate (RT) is a new short-acting GABA(A) receptor agonist, having potential to be an effective option for procedural sedation. Here, we aimed to compare the efficacy and safety of RT with propofol in patients undergoing upper gastrointestinal endoscopy.

METHODS

This positive-controlled, non-inferiority, phase III trial recruited patients at 17 centers, between September 2017 and November 2017. A total of 384 patients scheduled to undergo upper gastrointestinal endoscopy were randomly assigned to receive RT or propofol. Primary endpoint was the success rate of sedation. Adverse events (AEs) were recorded to evaluate safety.

RESULTS

The success rate of sedation in the RT group was non-inferior to that in the propofol group (97.34% vs 100.00%; difference in rate -2.66%, 95% CI -4.96 to -0.36, meeting criteria for non-inferiority). Patients in the RT group had longer time to adequate sedation (P < 0.0001) but shorter time to fully alert (P < 0.0001) than that in the propofol group. The incidences of hypotension (13.04% vs 42.86%, P < 0.0001), treatment-related hypotension (0.54% vs 5.82%, P < 0.0001), and respiratory depression (1.09% vs 6.88%, P = 0.0064) were significantly lower in the RT group. AEs were reported in 74 (39.15%) patients in the RT group and 114 (60.32%) patients in the propofol group, with significant difference (P < 0.0001).

CONCLUSION

This trial established non-inferior sedation success rate of RT compared with propofol. RT allows faster recovery from sedation compared with propofol. The safety profile is favorable and appears to be superior to propofol, indicating that it was feasible and well tolerated for patients.

Differences in midazolam premedication effects on recovery after short-duration ambulatory anesthesia with propofol or sevoflurane for gynecologic surgery in young patients: A randomized controlled trial

BACKGROUND

Anxiolytic premedication requires careful consideration owing to potential side effects including delayed recovery after ambulatory anesthesia. We aimed to compare the effect of midazolam on recovery profiles postoperatively, depending on whether propofol or sevoflurane was the primary anesthetic.

METHODS

We enrolled 226 patients (age, 18-50 years) undergoing ambulatory gynecologic laparoscopic surgery. Patients were categorized into propofol without midazolam (P), propofol with midazolam (MP), sevoflurane without midazolam (S), and sevoflurane with midazolam (MS) groups. As premedication, placebo or 0.02 mg/kg intravenous midazolam was used. The primary outcome was the difference in the time from anesthetic discontinuation to eye opening in response to verbal command. Secondary outcomes included postoperative nausea and pain occurrence and time to reach the discharge score.

RESULTS

The time from anesthetic discontinuation to eye opening was longer in the MP group (n = 49) than in the P group (n = 50; P < .001) but was not significantly different between the MS (n = 50) and S groups (n = 49; P = .1). Midazolam premedication did not significantly affect postoperative nausea in the MP group compared with that in the P group (P = .3) but had a nausea prevention effect in the MS group compared with that in the S group (P < .001). The time to reach the discharge score was similar in all patients regardless of midazolam administration.

CONCLUSION

In the recovery from short-duration ambulatory gynecologic surgery in young patients, intravenous midazolam premedication showed positive effects on postoperative nausea without affecting the time from anesthetic discontinuation to eye opening with sevoflurane-based anesthesia but prolonged the time from anesthetic discontinuation to eye opening with propofol-based anesthesia. Because this difference between the propofol groups is not clinically significant, the results support midazolam premedication in young women. Further studies assessing larger populations are needed.

Effects of Dexmedetomidine on the Pharmacokinetics of Dezocine, Midazolam and Its Metabolite 1-Hydroxymidazolam in Beagles by UPLC-MS/MS

Objective

We developed and validated a sensitive and reliable UPLC-MS/MS method for simultaneous determination of dezocine (DEZ), midazolam (MDZ) and its metabolite 1-hydroxymidazolam (1-OH-MDZ) in beagle plasma and investigated the effect of dexmedetomidine (DEX) on the pharmacokinetics of DEZ, MDZ and 1-OH-MDZ in beagles.

Materials and Methods

Diazepam was used as the internal standard (IS); the three analytes and IS were extracted by acetonitrile precipitation and separated on an Acquity UPLC BEH C18 column using acetonitrile-0.1% formic acid as mobile phase in gradient mode. In positive ion mode, the three analytes and IS were monitored by multiple reaction monitoring (MRM). Six beagles were designed as a double cycle self-control experiment with 0.15 mg/kg in the first cycle (Group A). After a 1-week washout period, the same six beagles were slowly injected intravenously with 2 µg/kg DEX in the second cycle (Group B), with continuous injection for 7 days. On the seventh day, 0.5 hr after intravenous injection of 2 µg/kg DEX, the six beagles were intramuscularly given with DEZ 0.33 mg/kg and MDZ 0.15 mg/kg.

Results

Under the conditions of this experiment, this method exhibited a good linearity for each analyte. The accuracy and precision were all within the acceptable limits in the bioanalytical method, and the results of recovery, matrix effect and stability have also met the requirements.

Conclusion

The developed UPLC-MS/MS method for simultaneous determination of DEZ, MDZ and 1-OH-MDZ in beagles plasma was accurate, reproducible, specific, and suitable. DEX could inhibit the metabolism of DEZ and MDZ and increase the exposure of DEZ and MDZ in beagles. Therefore, the change of therapeutic effect and the occurrence of adverse reactions caused by drug–drug interaction should be paid attention to when the drugs were used in combination.

The effect of midazolam as premedication on the quality of postoperative recovery after laparotomy: a randomized clinical trial

PURPOSE

Despite the uncertain effects of anxiolytic premedication with benzodiazepines on the quality of postoperative recovery, perioperative benzodiazepine administration is still a common practice in many hospitals. We evaluated the effect of premedication with midazolam on the quality of recovery in hospitalized patients undergoing a laparotomy.

METHODS

We conducted a single-centre randomized placebo-controlled, double-blinded clinical trial from July 2014 to September 2015. We included 192 patients aged > 18 yr scheduled for elective laparotomy with a planned postoperative stay of ≥ three days. Participants were randomized into two groups to receive either midazolam 3 mg or sodium chloride 0.9% intravenously as premedication prior to surgery. Patients were followed up for up to one week after surgery. The primary outcome was the Quality of Recovery-40 (QoR-40) score on postoperative day (POD) 3. The secondary outcomes included the QoR-40 score on POD 7, and the State-Trait Anxiety Inventory, State-Trait Anger Scale, Multidimensional Fatigue Inventory, and the Hospital Anxiety and Depression Scale scores.

RESULTS

The mean (standard deviation) postoperative QoR-40 scores on POD 3 were not significantly different in the midazolam group compared with controls [166.4 (17.0) vs 163.9 (19.8), respectively; mean difference, 2.3; 95% confidence interval, - 2.9 to 8.4; P = 0.35]. There were no between-group differences in any of the secondary outcomes.

CONCLUSIONS

Administration of midazolam as premedication for laparotomy patients did not improve the quality of recovery up to one week after surgery. General prescription of midazolam as premedication can be questioned and might only suit some patients.

TRIAL REGISTRATION

www.clinicaltrials.gov (NCT01993459); registered 29 October, 2013.