S(+)-ketamine : Current trends in emergency and intensive care medicine

Wilderness Medical Society Clinical Practice Guidelines for the Treatment of Acute Pain in Austere Environments: 2024 Update

The Wilderness Medical Society (WMS) convened an expert panel to develop evidence-based guidelines for the management of pain in austere environments. Recommendations are graded based on the quality of supporting evidence as defined by criteria put forth by the American College of Chest Physicians. This is an update of the 2014 version of the "WMS Practice Guidelines for the Treatment of Acute Pain in Remote Environments" published in Wilderness & Environmental Medicine 2014; 25:41-49.

The effect of low dose intra-articular S(+) ketamine on osteoarthritis in rats: an experimental study

BACKGROUND

This study aimed to investigate the analgesic impact of S(+)-ketamine on pain behavior and synovial inflammation in an osteoarthritis (OA) model.

METHODS

Animals were grouped as follows: OA-Saline (n = 24) and OA-Ketamine (n = 24), OA induced via intra-articular sodium monoiodoacetate (MIA); a Non-OA group (n = 24) served as the control. On the 7th day post OA induction, animals received either saline or S(+)-ketamine (0.5 mg.kg-1). Behavioral and histopathological assessments were conducted up to day 28.

RESULTS

S(+)-ketamine reduced allodynia from day 7 to 28 and hyperalgesia from day 10 to 28. It notably alleviated weight distribution deficits from day 10 until the end of the study. Significant walking improvement was observed on day 14 in S(+)-ketamine-treated rats. Starting on day 14, OA groups showed grip force decline, which was countered by S(+)-ketamine on day 21. However, S(+)-ketamine did not diminish synovial inflammation.

CONCLUSION

Low Intra-articular (IA) doses of S(+)-ketamine reduced MIA-induced OA pain but did not reverse synovial histopathological changes.

IRB APPROVAL NUMBER

23115 012030/2009-05.

Application of OFA-based ERAS for video-assisted thoracoscopic surgery in elderly patients with airway stenosis: A case report

BACKGROUND

Thoracic surgery without general anesthesia can be traced back to the First World War, and thoracic epidural block was used to complete the operation due to a large number of patients with gunshot wounds who needed emergency thoracic surgery. By reducing the intraoperative opioid dose, intraoperative and postoperative opioid-related adverse events such as respiratory depression, nausea and vomiting, delirium, hyperalgesia, and other side effects can be reduced to the benefit of patients.

METHODS

A 72-year-old male patient was admitted to the hospital with a 5-day history of multifocal pain throughout the body caused by a fall. The injury was not treated at that time, and the pain gradually increased, accompanied by cough with difficulty expelling sputum.

DIAGNOSES

Left lung contusion; traumatic pneumonia; multiple left rib fractures; left fluid pneumothorax; thyroid tumor of unknown nature, possibly malignant. Grade I tracheal stenosis; Sequelae of cerebral infarction. Because of goiter and severe tracheal compression, the patient was not intubated and received deopiated general anesthesia combined with epidural anesthesia to preserve spontaneous breathing.

OUTCOMES

At the end of the video-assisted thoracoscopic exploration, the patient was immediately conscious and returned directly to the ward 6 min later. The patient was able to move freely after surgery and eat normally within 6 h of surgery. The postoperative visual analog scale score was 2 points, and there were no anesthetic complications during the follow-up.

CONCLUSION

The opioid-free anesthesia strategy of tubeless general anesthesia, allowing spontaneous breathing combined with epidural anesthesia in elderly patients with tracheal stenosis undergoing video-assisted thoracoscopic surgery can not only avoid accidents and injuries caused by tracheal intubation and mechanical ventilation, but can also significantly reduce postoperative respiratory complications, optimize postoperative analgesia, and help achieve enhanced recovery after surgery.

The role of NMDARs in the anesthetic and antidepressant effects of ketamine

BACKGROUND

As a phencyclidine (PCP) analog, ketamine can generate rapid-onset and substantial anesthetic effects. Contrary to traditional anesthetics, ketamine is a dissociative anesthetic and can induce loss of consciousness in patients. Recently, the subanaesthetic dose of ketamine was found to produce rapid-onset and lasting antidepressant effects.

AIM

However, how different concentrations of ketamine can induce diverse actions remains unclear. Furthermore, the molecular mechanisms underlying the NMDAR-mediated anesthetic and antidepressant effects of ketamine are not fully understood.

METHOD

In this review, we have introduced ketamine and its metabolism, summarized recent advances in the molecular mechanisms underlying NMDAR inhibition in the anesthetic and antidepressant effects of ketamine, explored the possible functions of NMDAR subunits in the effects of ketamine, and discussed the future directions of ketamine-based anesthetic and antidepressant drugs.

RESULT

Both the anesthetic and antidepressant effects of ketamine were thought to be mediated by N-methyl-D-aspartate receptor (NMDAR) inhibition.

CONCLUSION

The roles of NMDARs have been extensively studied in the anaesthetic effects of ketamine. However, the roles of NMDARs in antidepressant effects of ketamine are complicated and controversial.

In Vitro Hepatotoxicity of Routinely Used Opioids and Sedative Drugs

A hepatocyte cell line was used to determine the hepatotoxicity of sedatives and opioids, as the hepatotoxicity of these drugs has not yet been well characterized. This might pose a threat, especially to critically ill patients, as they often receive high cumulative doses for daily analgosedation and often already have impaired liver function due to an underlying disease or complications during treatment. A well-established biosensor based on HepG2/C3A cells was used for the determination of the hepatotoxicity of commonly used sedatives and opioids in the intensive care setting (midazolam, propofol, s-ketamin, thiopental, fentanyl, remifentanil, and sufentanil). The incubation time was 2 × 3 days with clinically relevant (Cmax) and higher concentrations (C5× and C10×) of each drug in cell culture medium or human plasma. Afterward, we measured the cell count, vitality, lactate dehydrogenase (LDH), mitochondrial dehydrogenase activity, cytochrome P 450 1A2 (CYP1A2), and albumin synthesis. All tested substances reduced the viability of hepatocyte cells, but sufentanil and remifentanil showed more pronounced effects. The cell count was diminished by sufentanil in both the medium and plasma and by remifentanil only in plasma. Sufentanil and remifentanil also led to higher values of LDH in the cell culture supernatant. A reduction of mitochondrial dehydrogenase activity was seen with the use of midazolam and s-ketamine. Microalbumin synthesis was reduced in plasma after its incubation with higher concentrations of sufentanil and remifentanil. Remifentanil and s-ketamine reduced CYP1A2 activity, while propofol and thiopental increased it. Our findings suggest that none of the tested sedatives and opioids have pronounced hepatotoxicity. Sufentanil, remifentanil, and s-ketamine showed moderate hepatotoxic effects in vitro. These drugs should be given with caution to patients vulnerable to hepatotoxic drugs, e.g., patients with pre-existing liver disease or liver impairment as part of their underlying disease (e.g., hypoxic hepatitis or cholestatic liver dysfunction in sepsis). Further studies are indicated for this topic, which may use more complex cell culture models and global pharmacovigilance reports, addressing the limitation of the used cell model: HepG2/C3A cells have a lower metabolic capacity due to their low levels of CYP enzymes compared to primary hepatocytes. However, while the test model is suitable for parental substances, it is not for toxicity testing of metabolites.

Perioperative Ketamine and Cancer Recurrence: A Comprehensive Review

Cancer is a significant global health threat and a leading cause of death worldwide. Effective early-stage interventions, particularly surgery, can potentially cure many solid tumors. However, the risk of postoperative cancer recurrence remains high. Recent research highlights the influence of perioperative anesthetic and analgesic choices on the fate of residual cancer cells, potentially affecting recurrence risks. Among these agents, ketamine-a well-known anesthetic and analgesic-has garnered interest due to its antitumor properties, mainly through inhibiting the N-methyl-D-aspartate (NMDA) receptor found in various cancer tissues. Additionally, ketamine's potential immunomodulatory effects, given the expression of NMDA receptors on immune cells, suggest that it plays a significant role during the perioperative period. This review synthesizes current evidence on ketamine's impact on cancer cell biology, inflammation, immune modulation, and the role of the gut microbiota, proposing ketamine as a promising agent for enhancing oncological outcomes.

Substitution therapy for patients with alcohol dependence: Mechanisms of action and efficacy

New approaches for the treatment of alcohol dependence (AD) may improve patient outcomes. Substitution maintenance therapy is one of the most effective treatment options for opioid and nicotine use disorders. So far, there has been little attention to substitution therapy for the treatment of AD. Here, we explain the mechanistic foundations of alcohol substitution maintenance therapy. Alcohol has many primary targets in the brain (and other organs) and the physical interaction of ethanol molecules with these specific ethanol-sensitive sites on a variety of ionotropic receptors (e.g. GABA-A, NMDA, and nicotinic acetylcholine (nACh) receptors) and ion channels provides the rationale for substitution. As such, a variety of compounds can interact with those ethanol-sensitive sites and can thus substitute for some of the effects of alcohol. For some of these compounds, alcohol discrimination studies have shown their substitution potential. Accordingly, potential substitution treatments include agonists acting at GABA receptors such as sodium oxybate, baclofen and benzodiazepines, NMDA receptor antagonists such as ketamine and memantine, or nAChRs agonists such as varenicline. All these compounds are already approved for other indications and we present clinical evidence for these drugs in the treatment of alcohol withdrawal syndrome (AWS) and in the long-term treatment of AD, and outline future steps for their acceptance as substitution treatment in AD. Finally, we discuss the substitution approach of managed alcohol programs for the most severely affected homeless populations. Results showed that sodium oxybate is probably the closest to a substitution therapy for AD and is already approved for the treatment of AWS and in the long-term treatment of AD in some countries. In conclusion, we argue that better AD treatment can be provided if substitution maintenance treatments for alcohol are implemented at a similar scale as for opioid and nicotine use disorder.

Effect of esketamine combined with pregabalin on acute postsurgical pain in patients who underwent resection of spinal neoplasms: a randomized controlled trial

ABSTRACT

Moderate-to-severe acute postsurgical pain (APSP) can prolong the recovery and worsen the prognosis of patients who undergo spinal surgery. Esketamine and pregabalin may resolve APSP without causing hyperpathia or respiratory depression after surgery. However, there are other risks, such as dissociative symptoms. We designed a randomized controlled trial to investigate the effect of the combination of these 2 drugs on the incidence of APSP in patients who underwent resection of spinal neoplasms. Patients aged 18 to 65 years were randomized to receive esketamine (a bolus dose of 0.5 mg·kg-1 and an infusion dose of 0.12 mg·kg-1·h-1 for 48 hours after surgery) combined with oral pregabalin (75-150 mg/day, starting 2 hours before surgery and ending at 2 weeks after surgery) or an identical volume of normal saline and placebo capsules. The primary outcome was the proportion of patients with moderate-to-severe APSP (visual analog scale score ≥ 40) during the first 48 hours after surgery. Secondary outcomes included the incidence of drug-related adverse events. A total of 90 patients were randomized. The incidence of moderate-to-severe APSP in the combined group (27.3%) was lower than that in the control group (60.5%) during the first 48 hours after surgery (odds ratio = 0.25, 95% CI = 0.10-0.61; P = 0.002). The occurrence of mild dissociative symptoms was higher in the combined group than in the control group (18.2% vs 0%). In conclusion, esketamine combined with pregabalin could effectively alleviate APSP after spinal surgery, but an analgesic strategy might increase the risk of mild dissociative symptoms.

Effective dose of propofol combined with intravenous esketamine for smooth flexible laryngeal mask airway insertion in two distinct age groups of preschool children

BACKGROUND

There is limited research on the combined use of propofol and esketamine for anesthesia induction during flexible laryngeal mask airway (FLMA) in pediatric patients, and the effective dosage of propofol for FLMA smooth insertion remains unclear. We explored the effective dose of propofol combined with intravenous esketamine for the smooth insertion of FLMA in two distinct age groups of preschool children.

METHODS

This is a prospective, observer-blind, interventional clinical study. Based on age, preschool children scheduled for elective surgery were divided into group A (aged 1-3 years) and group B (aged 3-6 years). Anesthesia induction was started with intravenous administration of esketamine (1.0 mg.kg- 1) followed by propofol administration. The FLMA was inserted 2 min after propofol administration at the target dose. The initial dose of propofol in group A and group B was 3.0 mg.kg- 1 and 2.5 mg.kg- 1, respectively. The target dose of propofol was determined with Dixon's up-and-down method, and the dosing interval of propofol was 0.5 mg.kg- 1. If there was smooth insertion of FLMA in the previous patient, the target dose of propofol for the next patient was reduced by 0.5 mg.kg- 1; otherwise, it was increased by 0.5 mg.kg- 1. The median 50% effective dose (ED50) for propofol was estimated using Dixon's up-and-down method and Probit analysis, while the 95% effective dose (ED95) was estimated through Probit analysis. Vital signs and adverse events during induction were recorded.

RESULTS

Each group included 24 pediatric patients. Using Dixon's up-and-down method, the ED50 of propofol combined with esketamine for smooth insertion of FLMA in group A was 2.67 mg.kg- 1 (95%CI: 1.63-3.72), which was higher than that in group B (2.10 mg. kg- 1, 95%CI: 1.36-2.84) (p = 0.04). Using Probit analysis, the ED50 of propofol was calculated as 2.44 (95% CI: 1.02-3.15) mg.kg- 1 in group A and 1.93 (95% CI: 1.39-2.32) mg.kg- 1 in group B. The ED95 of propofol was 3.72 (95%CI: 3.07-15.18) mg.kg- 1 in group A and 2.74 (95%CI: 2.34-5.54) mg.kg- 1 in group B. In Group B, one pediatric patient experienced laryngospasm.

CONCLUSION

The effective dose of propofol when combined with intravenous esketamine for smooth insertion of FLMA in children aged 1-3 years is 2.67 mg.kg- 1, which is higher than that in children aged 3-6 years (2.10 mg. kg- 1).

TRIAL REGISTRATION

Chinese Clinical Trial Registry Center (Registration Number: ChiCTR2100044317; Registration Date: 2021/03/16).

Safety and efficacy of low-dose esketamine in laparoscopic cholecystectomy: a prospective, double-blind randomized controlled trial

BACKGROUND

Esketamine, recognized for its analgesic, sedative, and anti-inflammatory qualities, is integral in multimodal analgesia. However, the potential opioid-sparing effects of intravenous esketamine, along with its impact on inflammatory responses, and cognitive function during laparoscopic surgery, remain unexplored.

METHODS

In this study, 90 patients scheduled for laparoscopic cholecystectomy were equally randomized into three groups: a normal saline control group (NS), a low-dose esketamine group (LS) and a high-dose esketamine group (HS). Subsequently, we monitored several parameters: hemodynamics, levels of stress and inflammatory responses, intraoperative doses of sufentanil, remifentanil, and propofol, and 24-hour postoperative sufentanil requirements. We also evaluated alterations in cognitive function, perioperative indicators, and potential adverse reactions among the three groups.

RESULTS

Compared to their levels 5 minutes prior to anesthesia (T0) and 30 minutes post-operation (T4), the NS group exhibited a more significant decrease in Mean Arterial Pressure (MAP) and Heart Rate (HR) at various time intervals: 5 minutes after the skin incision (T1), 30 minutes post-incision (T2), and at the conclusion of the operation (T3), compared to the LS and HS groups(P < 0.05). Furthermore, the NS group exhibited a greater increase in levels of adrenaline (AD), noradrenaline (NE), endothelin (ET), C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6) at T1, T2, and T3, more so than the other two groups(P < 0.05). 24 hours after the surgery, patients in the LS group and HS group had significantly higher Montreal Cognitive Assessment (MoCA) scores than those in the NS group(P < 0.05). The LS and HS groups required lower doses of propofol, remifentanil, and sufentanil during surgery (P < 0.05), experienced shorter postoperative recovery times, and had lower incidences of nausea, vomiting, and respiratory depression compared to the NS group (P < 0.05).

CONCLUSION

The administration of low-dose esketamine has been shown to be safe, effective, and dependable in the context of laparoscopic gallbladder surgery. It has the capacity to stabilize hemodynamic responses, ameliorate both stress and inflammatory reactions from surgery, and hastens anesthesia recovery. Furthermore, it fosters the restoration of postoperative cognitive function. Notably, when combined with nalbuphine, it exhibits opioid-sparing effects, reducing postoperative adverse outcomes.

TRIAL REGISTRATION

The trial is registered with the China Clinical Trials Registry Registration Number: ChiCTR2300067596. Retrospectively registered (date of registration: 12/01/2023).

Esketamine induces apoptosis of nasopharyngeal carcinoma cells through the PERK/CHOP pathway

Nasopharyngeal carcinoma, a malignant tumor prevalent in southeast Asia and north Africa, still lacks effective treatment. Esketamine, an N-methyl-D-aspartatic acid (NMDA) receptor (NMDAR) antagonist, is widely used in clinical anesthesia. Emerging evidence suggests that esketamine plays an important role in inhibiting tumor cell activity. However, the underlying mechanisms of esketamine on nasopharyngeal carcinoma remain unknown. In this study, we found that esketamine inhibited the proliferation and migration of nasopharyngeal carcinoma cells. Mechanically, transcriptome sequencing and subsequent verification experiments revealed that esketamine promoted the apoptosis of nasopharyngeal carcinoma cells through endoplasmic reticulum stress PERK/ATF4/CHOP signaling pathway mediated by NMDAR. Additionally, when combined with esketamine, the inhibitory effect of cisplatin on the proliferation of nasopharyngeal carcinoma cells was significantly enhanced. These findings provide new insights into future anti-nasopharyngeal carcinoma clinical strategies via targeting the NMDAR/PERK/CHOP axis alone or in combination with cisplatin.

Esketamine mitigates cognitive impairment following exposure to LPS by modulating the intestinal flora/subdiaphragmatic vagus nerve/spleen axis

INTRODUCTION

Susceptibility to secondary infection often increases after primary infection. Secondary infections can lead to more severe inflammatory injuries; however, the underlying mechanisms are not yet fully elucidated.

OBJECTIVE

To investigate whether esketamine treatment immediately after primary lipopolysaccharide (LPS) exposure could alleviate cognitive impairment caused by secondary infection.

METHODS

Mice were injected intraperitoneally (IP) with LPS (5 mg/kg) 10 days apart. Esketamine (10, 15, or 30 mg/kg) was administered IP immediately after the primary LPS injection. Splenectomy or subdiaphragmatic vagotomy (SDV) was performed 7 days before secondary LPS exposure or broad-spectrum antibiotic administration.

RESULTS

Splenomegaly was observed after the primary LPS injection on Days 3 and 10. Splenomegaly was attenuated by treatment with 30 mg/kg esketamine. Esketamine treatment prevented increased plasma proinflammatory cytokines levels and cognitive dysfunction induced by secondary LPS exposure. Mice that underwent splenectomy or SDV had lower proinflammatory cytokines levels, higher hippocampal brain-derived neurotrophic factor (BDNF) levels, and improved cognitive function 1 day after secondary infection, which was not further improved by esketamine. Fecal microbiota transplantation (FMT) from endotoxic mice treated with esketamine attenuated hippocampal BDNF downregulation and cognitive dysfunction only in pseudo germ-free (PGF) mice without splenectomy. FMT with fecal suspensions from esketamine-treated endotoxic mice abrogated splenomegaly only in PGF mice without SDV. Blocking BDNF signaling blocked esketamine's ameliorating effects on secondary LPS exposure-induced cognitive dysfunction.

CONCLUSION

The intestinal flora/subdiaphragmatic vagus nerve/spleen axis-mediated hippocampal BDNF downregulation significantly affected secondary LPS-induced systemic inflammation and cognitive dysfunction. Esketamine preserves cognitive function via this mechanism.

Comparison of the effects of esketamine, sufentanil, or lidocaine combined with propofol on tussis reflection during upper gastrointestinal endoscopy: study protocol for a randomised, two centre, three-blind, controlled trial

BACKGROUND

Tussis, which increases the incidence of airway spasm, aspiration, nausea, and vomiting, is a common complication faced during upper gastrointestinal (GI) endoscopy. However, sedatives and analgesics exhibit inhibitory actions against airway reflexes to different degrees. Our assumption is a combination of propofol and small doses of sufentanil, esketamine, or lidocaine, especially the combination of propofol and esketamine, might reduce tussis incidence.

METHOD

The study will be performed as a randomised controlled three-blind, two-centre trial. Patients undergoing upper GI endoscopy, ≥ 18 years old, with American Society of Anesthesiologists (ASA) classification I-III will be randomised to four groups: P group (single administration of propofol), P + S group (administration of propofol and sufentanil in combination), P + K group (administration of propofol and esketamine in combination), and P + L group (administration of propofol and lidocaine in combination) (N = 100 per group). The primary endpoints include the frequency of tussis, nausea and vomiting, and/or body movements observed at the insertion of the endoscope into the pharyngeal cavity or within 5 min of endoscope insertion. Secondary outcomes are recovery assessment, patients' and endoscopists' satisfaction with the procedure, MMSE scores, MET scores, sleep condition, and the number of sedation-related events. Data on sedation-related events are collected by recording of vital signs. Satisfaction parameters and mental states are collected by means of questionnaires and evaluation scales before and after the procedure and on different following days.

DISCUSSION

Esketamine can reduce tussis occurrence with good tolerability and relax the bronchus and also provides high clearance rates and low possibility of adverse reactions. We aim to demonstrate that the combination of esketamine with propofol for sedation in patients subjected to upper GI procedure is nevertheless superior to only administration of propofol or a combination of propofol with other anaesthetics, such as opioids or lidocaine.

TRIAL REGISTRATION

ClinicalTrials.gov. NCT05497492 , Registered 09 August 2022.

The effects of esketamine on blood pressure and hypotension incidence during induction of bariatric surgery: A randomized controlled trial

BACKGROUND

The prevalence of obesity is high. Bariatric surgery is an effective treatment for severe obesity; however, the induction phase of anesthesia in these patients poses a risk of hypotension. Esketamine, known for its sympathetic nervous system stimulation, may stabilize blood pressure during induction. This study aimed to investigate the effects of esketamine on blood pressure in bariatric surgery patients.

METHODS

This randomized controlled trial included 145 patients undergoing bariatric surgery. Patients were randomly assigned to receive esketamine or a control intervention during induction. Blood pressure and other vital signs were measured and compared between the 2 groups using statistical analyses.

RESULTS

Administration of esketamine increased blood pressure before intubation (T2). The incidence of hypotension was lower in the esketamine group at multiple time points during induction. Postoperatively, the esketamine group exhibited lower pain scores at 24 hours and a reduced need for rescue analgesics.

CONCLUSION

A single dose of 0.2 mg/kg esketamine during the induction phase of bariatric surgery can improve blood pressure stability and decrease the incidence of hypotension. Furthermore, it is associated with reduced postoperative pain. Future studies could explore the effects of higher esketamine doses and validate these findings in a larger and more diverse patient population.

Effect of Esketamine Added to Propofol Sedation on Desaturation and Hypotension in Bidirectional Endoscopy: A Randomized Clinical Trial

Importance

Propofol sedation is widely used for endoscopic procedures, but it poses risks of hemodynamic and respiratory depression. The addition of esketamine as an adjuvant may reduce propofol requirements and associated adverse events.

Objective

To evaluate the effects of low-dose esketamine added to propofol-based sedation on desaturation and hypotension during same-visit bidirectional endoscopy.

Design, Setting, and Participants

This multicenter, double-blind, placebo-controlled randomized clinical trial assessed patients from 3 teaching hospitals in China who were scheduled for same-visit bidirectional endoscopy between February 8 and November 30, 2022, and randomly assigned to receive esketamine or normal saline (placebo).

Interventions

After induction of sedation with 0.1 μg/kg of sufentanil and 0.5 mg/kg of propofol, patients in the esketamine group received 0.15 mg/kg of intravenous esketamine, whereas patients in the placebo group received an equivalent volume of saline. Sedation was achieved through propofol titration.

Main Outcomes and Measures

The primary outcome was the composite of desaturation and hypotension during the procedures. Secondary outcomes included desaturation, hypotension, propofol requirements, postprocedure pain and fatigue, nausea or vomiting, dizziness or headache, hallucination or nightmare, endoscopist satisfaction, and patient satisfaction.

Results

Among the 663 initially enrolled patients, 660 completed the study (median [IQR] age, 48 [36-57] years; 355 [53.8%] female), with 331 randomized to the esketamine group and 329 to the placebo group. The administration of esketamine compared with placebo significantly reduced the incidence of the composite outcome of desaturation and hypotension (8.2% vs 21.0%; difference, -12.8 percentage points; odds ratio [OR], 0.34; 95% CI, 0.21-0.54; P < .001). Additionally, esketamine led to significantly lower incidences of desaturation (OR, 0.36; 95% CI, 0.18-0.72; false discovery rate q = .01) and hypotension (OR, 0.33; 95% CI, 0.18-0.60; q < .001) and reduced propofol requirements (difference, -58.9 mg; 95% CI, -65.7 to -52.2 mg; q < .001), without significant effects on other secondary outcomes.

Conclusions and Relevance

In this randomized clinical trial of patients undergoing same-visit bidirectional endoscopy, the administration of low-dose esketamine resulted in an approximately 61% reduction in the incidence of desaturation and hypotension, accompanied by decreased propofol requirements. These findings support the use of esketamine as an adjuvant to propofol-based sedation in endoscopic procedures.

Trial Registration

Chinese Clinical Trial Registry Identifier: ChiCTR2200055938.

Evaluating the effects of S-ketamine on postoperative delirium in elderly patients following total hip or knee arthroplasty under intraspinal anesthesia: a single-center randomized, double-blind, placebo-controlled, pragmatic study protocol

Introduction

Postoperative delirium (POD) is an acute, transient brain disorder associated with decreased postoperative quality of life, dementia, neurocognitive changes, and mortality. A small number of trials have explored the role of S-ketamine in the treatment of POD due to its neuroprotective effects. Surprisingly, these trials have failed to yield supportive results. However, heterogeneity in delirium assessment methodologies, sample sizes, and outcome settings as well as deficiencies in S-ketamine use methods make the evidence provided by these studies less persuasive. Given the severe impact of POD on the health of elderly patients and the potential for S-ketamine to prevent it, we believe that designing a large sample size, and rigorous randomized controlled trial for further evaluation is necessary.

Methods

This is a single-center, randomized, double-blind, placebo-controlled, pragmatic study. Subjects undergoing total hip or knee arthroplasty will be randomized in a 1:1 ratio to intervention (n = 186) and placebo (n = 186) groups. This trial aims to explore the potential role of S-ketamine in the prevention of POD. Its primary outcome is the incidence of POD within 3 postoperative days. Secondary outcomes include the number of POD episodes, the onset and duration of POD, the severity and subtype of POD, pain scores and opioid consumption, sleep quality, clinical outcomes, and safety outcomes.

Discussion

To our knowledge, this is the first pragmatic study that proposes to use S-ketamine to prevent POD. We reviewed a large body of literature to identify potential preoperative confounding variables that may bias associations between the intervention and primary outcome. We will use advanced statistical methods to correct potential confounding variables, improving the test's power and external validity of test results. Of note, the patient population included in this trial will undergo intraspinal anesthesia. Although large, multicenter, randomized controlled studies have found no considerable difference in the effects of regional and general anesthesia on POD, patients receiving intraspinal anesthesia have less exposure to at-risk drugs, such as sevoflurane, propofol, and benzodiazepines, than patients receiving general anesthesia. At-risk drugs have been shown to negatively interfere with the neuroprotective effects of S-ketamine, which may be the reason for the failure of a large number of previous studies. There is currently a lack of randomized controlled studies evaluating S-ketamine for POD prevention, and our trial helps to fill a gap in this area.Trial registration: http://www.chictr.org.cn, identifier ChiCTR2300075796.

Safety and tolerability of esketamine in propofol based sedation for endoscopic variceal ligation with or without injection sclerotherapy: Randomized controlled trial

OBJECTIVES

Esketamine is an S (+) enantiomer of ketamine with greater potency and similar psychomimetic effects compared to racemic ketamine. We aimed to explore the safety of esketamine in different doses as an adjuvant to propofol in patients undergoing endoscopic variceal ligation (EVL) with or without injection sclerotherapy.

METHODS

One hundred patients were randomized to receive sedation with propofol 1.5 mg/kg in combination with sufentanil 0.1 μg/kg (group S), esketamine 0.2 mg/kg (group E0.2), esketamine 0.3 mg/kg (group E0.3), or esketamine 0.4 mg/kg (group E0.4) for EVL (n = 25 each). Hemodynamic and respiratory parameters were recorded during the procedure. The primary outcome was the incidence of hypotension; secondary outcomes included the incidence of desaturation, positive and negative syndrome scale (PANSS) after the procedure, pain score after the procedure, and secretion volume.

RESULTS

The incidence of hypotension was significantly lower in groups E0.2 (36%), E0.3 (20%), and E0.4 (24%) than in group S (72%). The incidence of SpO2  ≤94% was significantly lower in group E0.4 (4%) than in group S (32%). No significant intergroup difference was found in the PANSS assessment.

CONCLUSIONS

Combining 0.4 mg/kg esketamine with propofol sedation was optimal to facilitate EVL with stable hemodynamic status and better respiratory function during the procedure, without significant psychomimetic side-effects.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (Trial ID: ChiCTR2100047033, http://www.chictr.org.cn/showproj.aspx?proj=127518).

Dexmedetomidine compared to low-dose ketamine better protected not only the brain but also the lungs in acute ischemic stroke

BACKGROUND

Dexmedetomidine (DEX) and low-dose ketamine (KET) present neuroprotective effects in acute ischemic stroke (AIS); however, to date, no studies have evaluated which has better protective effects not only on the brain but also lungs in AIS.

METHODS

AIS-induced Wistar rats (390 ± 30 g) were randomized after 24-h, receiving dexmedetomidine (STROKE-DEX, n = 10) or low-dose S(+)-ketamine (STROKE-KET, n = 10). After 1-h protective ventilation, perilesional brain tissue and lungs were removed for histologic and molecular biology analysis. STROKE animals (n = 5), receiving sodium thiopental but not ventilated, had brain and lungs removed for molecular biology analysis. Effects of DEX and KET mean plasma concentrations on alveolar macrophages, neutrophils, and lung endothelial cells, extracted primarily 24-h after AIS, were evaluated.

RESULTS

In perilesional brain tissue, apoptosis did not differ between groups. In STROKE-DEX, compared to STROKE-KET, tumor necrosis factor (TNF)-α and vascular cell adhesion molecule-1 (VCAM-1) expressions were reduced, but no changes in nuclear factor erythroid 2-related factor-2 (Nrf2) and super oxide dismutase (SOD)-1 were observed. In lungs, TNF-α and VCAM-1 were reduced, whereas Nrf2 and SOD-1 were increased in STROKE-DEX. In alveolar macrophages, TNF-α and inducible nitric oxide synthase (M1 macrophage phenotype) were lower and arginase and transforming growth factor-β (M2 macrophage phenotype) higher in STROKE-DEX. In lung neutrophils, CXC chemokine receptors (CXCR2 and CXCR4) were higher in STROKE-DEX. In lung endothelial cells, E-selectin and VCAM-1 were lower in STROKE-DEX.

CONCLUSIONS

In the current AIS model, dexmedetomidine compared to low-dose ketamine reduced inflammation and endothelial cell damage in both brain and lung, suggesting greater protection.

Esketamine versus Sufentanil Applied Prior to Placement of Suspension Laryngoscope

OBJECTIVE

In laryngeal microsurgery, the insertion of the suspension laryngoscope is a strong stimulus that may cause hemodynamic fluctuations and adverse cardiovascular events. The purpose of this study was to compare the effect of preemptive treatment with esketamine and sufentanil on maintaining hemodynamics and reducing the occurrence of adverse cardiovascular events during the insertion of suspension laryngoscope.

METHODS

In this double-blind randomized controlled trial, patients undergoing general anesthesia for laryngeal microsurgery were randomly assigned (1:1) to esketamine 0.5 mg kg-1 (esketamine group) and sufentanyl 0.125 μg kg-1 (sufentanil group) before inserting the laryngoscope, respectively.

RESULTS

During the insertion of suspension laryngoscope, the incidence of bradycardia (HR < 60 beats/min) was 39.3% (22/56) in esketamine group, lower than 60.0% (33/55) in sufentanil group (odds ratio [OR], 2.32 [95% CI, 1.11-5.08]; p = 0.029). The incidence of hypotension (MAP <65 mmHg) was 33.9% (19/56) in esketamine group, lower than 56.4% (31/55) in sufentanil group (odds ratio [OR], 2.52 [95% CI, 1.91-5.27]; p = 0.018). The frequency of hypotension in esketamine group was lower than that in sufentanil group (0.36 ± 0.52 vs. 0.56 ± 0.50, p = 0.035). The time-weighted average of HR dropping above 30% of baseline was smaller in esketamine group than in sufentanil group (0.52 ± 2.06 vs. 1.08 ± 2.77, p = 0.006).

CONCLUSIONS

These findings showed that compared with preemptive treatment of sufentanil (0.125 μg kg-1 ), esketamine (0.5 mg kg-1 ) was effective in reducing the incidence of cardiovascular adverse events, including bradycardia and hypotension induced by the insertion of suspension laryngoscope during the laryngeal microsurgery.

LEVEL OF EVIDENCE

2 Laryngoscope, 133:3021-3027, 2023.

Opioid Free Total Intravenous Anesthesia With Dexmedetomidine-Esketamine-Lidocaine for Patients Undergoing Lumpectomy

Background

The aim of the study was to evaluate the feasibility of the opioid-free anesthesia (OFA) technique with dexmedetomidine, esketamine, and lidocaine among patients diagnosed with benign breast mass and scheduled for lumpectomy.

Methods

We enrolled 80 female patients who were aged from 18 to 60 years, graded with American Society of Anesthesiologists physical status I or II, diagnosed with benign breast mass, and scheduled for lumpectomy. These patients were randomly treated with OFA or opioid-based anesthesia (OBA). Dexmedetomidine-esketamine-lidocaine and sufentanil-remifentanil were administered in OFA and OBA group, respectively. We mainly compared the analgesic efficacy of OFA and OBA technique, as well as intraoperative hemodynamics, the quality of recovery, and satisfaction score of patients.

Results

There was no significant difference between the two groups with regard to visual analogue scale (VAS) score at 2, 12, and 24 h after extubation. However, the time to first rescue analgesic was prolonged in OFA group than that in OFB group (6.18 ± 1.00 min vs. 7.40 ± 0.92 min, P = 0.000). Further, mean arterial pressure and heart rate at T0 (entering operating room), T1 (before anesthesia induction), T2 (immediately after intubation), T3, T4, and T5 (1, 5, and 10 min after surgical incision, respectively) were significantly higher in OFA group than that in OBA group. Incidence of hypotension and bradycardia was lower in OFA group. Consistently, fewer patients in OFA group consumed atropine (8% vs. 32%, P = 0.019) and ephedrine (5% vs. 38%, P = 0.001) compared to OBA group. Furthermore, patients in OFA group had a longer awakening time (7.14 ± 2.63 min vs. 4.54 ± 1.14 min, P = 0.000) and recovery time of orientation (11.76 ± 3.15 min vs. 6.92 ± 1.19 min, P = 0.000). Fewer patients in the OFA group experienced postoperative nausea and vomiting (PONV) (11% vs. 51%, P = 0.000) and consumed ondansetron (5% vs. 35%, P = 0.003) compared to OBA group. And patients in OFA group had a higher satisfaction score than those in OBA group (9 (8 - 9) vs. 7 (7 - 8), P = 0.000).

Conclusion

For patients undergoing lumpectomy, OFA technique with dexmedetomidine-esketamine-lidocaine showed a better postoperative analgesic efficacy, a more stable hemodynamics, and a lower incidence of PONV. However, such advantage of OFA technique should be weighed against a longer awakening time and recovery time of orientation in clinical practice.

Effect of Intraoperative Infusion of Esketamine on Quality of Postoperative Recovery in Patients Undergoing Laparoscopic Bariatric Surgery: A Randomized Controlled Trial

INTRODUCTION

This study aims to evaluate the efficacy of esketamine on postoperative recovery quality after laparoscopic bariatric surgery.

METHODS

Patients (n = 74) scheduled for laparoscopic bariatric surgery were randomly divided into two groups: the esketamine group (group E: 0.5 mg/kg/h infusion, i.e., 0.2 mL/kg/h) or the control group (group C: 0.2 mL/kg/h normal saline infusion). The infusions were stopped 20 min before the end of the procedure. The primary outcome was the Quality of Recovery-40 (QoR-40) score on postoperative day 1 (POD 1). The secondary outcomes included QoR-40 scores on PODs 2 and 7, Numeric Rating Scale (NRS) on PODs 1, 2, and 7, time to extubation, additional postoperative analgesic use, length of hospital stay, and time to first exhaust. Additonally, the safety indices were also recorded, including hemodynamic profile, perioperative anesthesia index (Ai), utilization of vasoactive drugs or urapidil, and side effects.

RESULTS

All in all, 70 of the 74 patients completed the study, 35 in each group. The difference of QoR-40 scores on POD 1 was both statistically and clinically significant [difference 7.21, 95% confidence interval (CI) 5.17, 9.25, p < 0.001]. The difference of QoR-40 on POD 2 was statistically significant but clinically insignificant (difference 4.81, 95% CI 2.69, 6.92, p < 0.001). The difference of NRS scores on POD 1 was statistically significant (difference -1.23, 95% CI -2.36, -0.10, p = 0.033). Compared with group C, group E had a lower utilization rate of phenylephrine and higher Ai values (p < 0.05). There was no statistical difference between the two groups on other measures.

CONCLUSION

Continuous ketamine infusion seems to be safe and well tolerated in laparoscopic bariatric surgery. It improved the quality of postoperative recovery and reduced pain on POD 1. In spite of the increased Ai value during the surgery, it also provided better hemodynamics with less usage of phenylephrine.

Intraoperative intravenous low-dose esketamine improves quality of early recovery after laparoscopic radical resection of colorectal cancer: A prospective, randomized controlled trial

BACKGROUND

Esketamine has higher potency, stronger receptor affinity, a stronger analgesic effect, a higher in vivo clearance rate, and a lower incidence of adverse reactions when compared to ketamine. However, there have been few ketamine studies to assess patient-centered, overall recovery outcomes from the perspective of patients with colorectal cancer.

METHODS

This was a prospective, randomized controlled trial. Ninety-two patients undergoing laparoscopic radical resection of colorectal cancer were randomly assigned to either the esketamine (K group) or non-eskatamine (C group) group. After anesthesia induction, a loading dose of 0.25 mg/kg was administered, followed by continuous infusion at a rate of 0.12 mg.kg-1.h-1 until closure of surgical incisions in the K group. In the C group, an equivalent volume of normal saline was infused. The primary outcome was quality of recovery at 24 h after surgery, as measured by the Quality of Recovery-15 (QoR-15) scale. The QoR-15 was evaluated at three timepoints: before (Tbefore), 24 h (T24h) and 72 h (T72h) after surgery.

MAIN RESULTS

A total of 88 patients completed this study. The total QoR-15 scores in K group (n = 45) were higher than in the C group (n = 43) at 24 h: 112.33 ± 8.79 vs. 103.93 ± 9.03 (P = 0.000) and at 72 h: 118.73 ± 7.82 vs. 114.79 ± 7.98 (P = 0.022). However, the differences between the two groups only had clinical significance at 24 h after surgery. Among the five dimensions of the QoR-15, physical comfort (P = 0.003), emotional state (P = 0.000), and physical independence (P = 0.000) were significantly higher at 24 h in the K group, and physical comfort (P = 0.048) was higher at 72 h in the K group.

CONCLUSIONS

This study found that intraoperative intravenous low-dose esketamine could improve the early postoperative quality of recovery in patients undergoing laparoscopic radical resection of colorectal cancer from the perspective of patients.

Efficacy and safety of perioperative application of ketamine on postoperative depression: A meta-analysis of randomized controlled studies

Ketamine, a commonly used general anesthetic, can produce rapid and sustained antidepressant effect. However, the efficacy and safety of the perioperative application of ketamine on postoperative depression remains uncertain. We performed a meta-analysis to determine the effect of perioperative intravenous administration of ketamine on postoperative depression. Randomized controlled trials comparing ketamine with placebo in patients were included. Primary outcome was postoperative depression scores. Secondary outcomes included postoperative visual analog scale (VAS) scores for pain and adverse effects associated with ketamine. Fifteen studies with 1697 patients receiving ketamine and 1462 controls were enrolled. Compared with the controls, the ketamine group showed a reduction in postoperative depression scores, by a standardized mean difference (SMD) of -0.97, 95% confidence interval [CI, -1.27, -0.66], P < 0.001, I2 = 72% on postoperative day (POD) 1; SMD-0.65, 95% CI [-1.12, -0.17], P < 0.001, I2 = 94% on POD 3; SMD-0.30, 95% CI [-0.45, -0.14], P < 0.001, I2 = 0% on POD 7; and SMD-0.25, 95% CI [-0.38, -0.11], P < 0.001, I2 = 59% over the long term. Ketamine reduced VAS pain scores on POD 1 (SMD-0.93, 95% CI [-1.58, -0.29], P = 0.005, I2 = 97%), but no significant difference was found between the two groups on PODs 3 and 7 or over the long term. However, ketamine administration distinctly increased the risk of adverse effects, including nausea and vomiting (risk ratio [RR] 1.40, 95% CI [1.12, 1.75], P = 0.003, I2 = 30%), headache (RR 2.47, 95% CI [1.41, 4.32], P = 0.002, I2 = 19%), hallucination (RR 15.35, 95% CI [6.24, 37.34], P < 0.001, I2 = 89%), and dizziness (RR 3.48, 95% CI [2.68, 4.50], P < 0.001, I2 = 89%) compared with the controls. In conclusion, perioperative application of ketamine reduces postoperative depression and pain scores with increased risk of adverse effects.

Thrifty effect of subanesthetic-dose S-ketamine on postoperative opioids and its safety and analgesic effectiveness: A prospective, triple-blind, randomized controlled, polycentric clinical trial

Aim

To investigate the thrifty effects of subanesthetic-dose S-ketamine on postoperative opioids and its safety and analgesic efficacy.

Methods

Four-hundred and twenty patients were divided into the control group (CON group), the S-ketamine 0.2 mg/kg group (ES0.2 group), and the S-ketamine 0.3 mg/kg group (ES0.3 group) randomly. Major indicators include the Visual Analogue Scale (VAS), the times of compression with analgesic pumps after surgery, and analgesic drug consumption from anesthesia induction to 48 h after surgery. Minor records include vital signs, the use of vasoactive drugs, the Ramsay scores, the occurrence of adverse events including nervous system reaction, and the patient's satisfaction with anesthesia.

Results

Compared with the CON group, VAS scores decreased in the ES0.2 and ES0.3 groups (p < 0.05). At 10 min after extubation, the VAS scores of the ES0.3 group were lower than that of the ES0.2 group (p < 0.05). The total number of compression with analgesic pumps of the ES0.3 group was lower than that of the CON group (p < 0.05). The opioid consumption after surgery of the ES0.3 group was lower than those of the CON group and the ES0.2 group (p < 0.05). The ES0.3 group's heart rate (HR) was faster but the use of vasoactive, drug consumption was less than the other two groups (p < 0.05). There were no significant differences in the incidence of postoperative adverse events and anesthetic satisfaction among the three groups.

Conclusion

Subanesthetic-dose S-ketamine at 0.2-0.3 mg/kg especially the 0.3 mg/kg in general anesthesia induction can safely and effectively reduce postoperative pain and save postoperative opioid consumption.

Evaluating efficacy and safety of sub-anesthetic dose esketamine as an adjuvant to propofol/remifentanil analgosedation and spontaneous respiration for children flexible fibreoptic bronchoscopy: a prospective, double-blinded, randomized, and placebo-controlled clinical trial

Background: Flexible fiberoptic bronchoscopy (FFB) for children is widely performed under sedation. Currently, the optimal sedation regimen remains unclear. Esketamine is an N-methyl-D-aspartic acid (NMDA) receptor antagonist, which has stronger sedative and analgesic effects and exerts less cardiorespiratory depression than other sedatives. The purpose of this study was to evaluate whether a subanesthetic dose of esketamine as an adjuvant to propofol/remifentanil and spontaneous ventilation compared with control reduces the procedural and anesthesia-related complications of FFB in children. Materials and methods: Seventy-two children ≤ 12 years of age who were scheduled for FFB were randomly assigned, in a 1:1 ratio, to the esketamine-propofol/remifentanil (Group S, n = 36) or to the propofol/remifentanil group (Group C, n = 36). All children were retained spontaneous ventilation. The primary outcome was the incidence of oxygen desaturation (respiratory depression). Perioperative hemodynamic variables, blood oxygen saturation (SPO₂), end-tidal partial pressure of carbon dioxide (PetCO₂), respiratory rate (R), and the Bispectral index (BIS), induction time, procedural time, recovery time, the time to the ward from the recovery room, consumption of propofol and remifentanil during the procedure and the appearance of adverse events, including paradoxical agitation following midazolam administration, injection pain, laryngospasm, bronchospasm, PONV, vertigo, and hallucination were also compared. Results: The incidence of oxygen desaturation was significantly lower in Group S (8.3%) compared to Group C (36.1%, p = 0.005). The perioperative hemodynamic profile including SBP, DBP, and HR were more stable in Group S than that in Group C (p < 0.05). Consumption of propofol and remifentanil was lower in Group S than in Group C (p < 0.05). Furthermore, PAED scores, cough scores and injection pain were lower in the Group S than in Group C (p < 0.05). The recovery time of Group S was slightly longer than that of Group C (p < 0.05). Nobody happened paradoxical agitation following midazolam administration, PONV, vertigo, and hallucinations in both groups (p > 0.05). Conclusion: Our findings indicate that a subanesthetic dose of esketamine as an adjuvant to propofol/remifentanil and spontaneous respiration is an effective regimen for children undergoing FFB. Our findings will provide a reference for clinical sedation practice during these procedures in children. Clinical Trail Registration: Chinese clinicaltrials.gov registry (identifier: ChiCTR2100053302).

Efficacy and Safety of a Subanesthetic Dose of Esketamine Combined with Propofol in Patients with Obesity Undergoing Painless Gastroscopy: A Prospective, Double-Blind, Randomized Controlled Trial

Purpose

Patients with obesity are more susceptible to hypoxemia. Anesthetic management for patients with obesity undergoing painless gastroscopy presents a severe challenge for anesthesiologists. Esketamine is a NMDA antagonist that has been proven to be beneficial for ameliorating respiratory depression owing to its sympathomimetic effect; however, there are no relevant reports on its use in patients with obesity. We designed a randomized controlled trial to evaluate whether esketamine can be the ideal adjuvant to propofol sedation in patients with obesity undergoing painless gastroscopy.

Patients and Methods

A total of 104 patients with obesity undergoing painless gastroscopy were randomly divided into group C (propofol+saline) and group S (propofol+esketamine 0.25 mg/kg). Anesthesia was induced by 2 mg/kg propofol with saline or esketamine. The consumption of propofol, hemodynamic parameters, duration of procedure, induction time, postoperative awakening time, and orientation recovery time were recorded. Adverse events and satisfaction scores were also recorded.

Results

Propofol consumption was 274.4±22.6 mg and 201.3±16.6 mg in groups C and S, respectively. The induction time of groups C and S were 25.4±2.3 s and 17.8±1.9 s, respectively. The postoperative awakening times of groups C and S were 6.2±1.1 min and 4.8±1.3 min, respectively. Hemodynamic parameters were more stable in group S than in group C. The incidence of adverse events such as injection pain, hypoxemia, hypotension, bradycardia, choking, and body movement were significantly lower in group S. The satisfaction scores of the endoscopist and anesthesiologist were (4.58±0.49 vs 3.71±0.83) and (4.75±0.44 vs 3.33±0.92), respectively.

Conclusion

The combination of propofol and esketamine (0.25 mg/kg) improves the safety and reduces the incidence of adverse events in patients with obesity during painless gastroscopy. Thus, this method is worthy of clinical application.

Clinical Trials Registration

ChiCTR 2200062547.

Advantages of Sedation With Remimazolam Compared to Midazolam for the Removal of Impacted Tooth in Patients With Dental Anxiety

PURPOSE

Although midazolam is commonly used to sedate patients with dental anxiety, it has shortcomings that reduce the satisfaction of patients and doctors. The aim of this study was therefore to explore the advantages of remimazolam as a sedative.

METHODS

The study design was a prospective randomized controlled trial. Patients with dental anxiety and who were to undergo impacted tooth removal were randomized into remimazolam and midazolam groups. They were sedated with remimazolam or midazolam prior to receiving nerve blocker. The predictor variable was the type of sedative, while the primary outcome variables were the onset time, awakening time, recovery time, and postoperative side effects. Secondary outcome variables were the Modified Dental Anxiety Scale score before and after surgery, patient satisfaction and comfort levels scores, and doctor satisfaction level scores. Other variables included the patient demographics and the operation time. Data were analyzed using the Student's t-test, Mann-Whitney test, χ² test, and two-way repeated measurement ANOVA test (SPSS Version 25.0).

RESULTS

A total of 83 patients were included in this study, with 42 randomized to the remimazolam group and 41 to the midazolam group. There were no significant differences between the two groups in terms of demographic features and operation time. Patients in the remimazolam group had significantly shorter onset time, awakening time, and recovery time compared to those in the midazolam group (each P < .001). Postoperative side effects were more frequent in the midazolam group (P < .001). Following surgery, the Modified Dental Anxiety Scale scores in both groups were significantly lower than prior to surgery (P < .001). Satisfaction levels scores for the patients and doctor were higher in the remimazolam group than in the midazolam group (P < .001).

CONCLUSIONS

The use of remimazolam results in faster onset, more rapid recovery, and lower incidence of postoperative side effects compared to midazolam, leading to improved satisfaction for patients and doctors. Remimazolam therefore appears to have several advantages over midazolam for the sedation of patients with dental anxiety associated with the removal of impacted teeth.

Effects of esketamine on postoperative rebound pain in patients undergoing unilateral total knee arthroplasty: a single-center, randomized, double-blind, placebo-controlled trial protocol

Introduction

Rebound pain, transient and acute postoperative pain after the disappearance of regional block anesthesia, has been a concern in recent years. Insufficient preemptive analgesia and hyperalgesia induced by regional block are the main mechanisms. At present, the evidence for the treatment of rebound pain is limited. The esketamine, as an antagonist of the N-methyl-D-aspartate receptor, has been proven to prevent hyperalgesia. Therefore, this trial aims to evaluate the impact of esketamine on postoperative rebound pain in patients undergoing total knee arthroplasty.

Methods/design

This study is a single-center, prospective, double-blind, randomized, placebo-controlled trial. Participants who plan to undergo total knee arthroplasty will be randomly assigned to the esketamine group (N = 178) and placebo group (N = 178) in a ratio of 1:1. This trial aims to evaluate the impact of esketamine on postoperative rebound pain in patients undergoing total knee arthroplasty. The primary outcome of this trial is the incidence of rebound pain within 12 h after the operation in the esketamine group and the placebo group. The secondary outcome will be to compare (1) the incidence of rebound pain 24 h after the operation; (2) the time to enter the pain cycle for the first time within 24 h after the procedure; (3) the first time of rebound pain occurred within 24 h after surgery; (4) the modified rebound pain score; (5) NRS score under rest and exercise at different time points; (6) the cumulative opioid consumption at different time points; (7) patient's prognosis and knee joint function evaluation; (8) blood glucose and cortisol concentration; (9) patient's satisfaction score; (10) adverse reactions and adverse events.

Discussion

The effect of ketamine on preventing postoperative rebound pain is contradictory and uncertain. The affinity of esketamine to the N-methyl-D-aspartate receptor is about four times higher than levo-ketamine, the analgesic effect is 3 times higher than levo-ketamine, and there are fewer adverse mental reactions. To our knowledge, there is no randomized controlled trial to verify the impact of esketamine on postoperative rebound pain in patients undergoing total knee arthroplasty. Therefore, this trial is expected to fill an important gap in relevant fields and provide novel evidence for individualized pain management.

Clinical Trial Registration

http://www.chictr.org.cn, identifier ChiCTR2300069044.

Management of Hemorrhagic Shock: Physiology Approach, Timing and Strategies

Hemorrhagic shock (HS) management is based on a timely, rapid, definitive source control of bleeding/s and on blood loss replacement. Stopping the hemorrhage from progressing from any named and visible vessel is the main stem fundamental praxis of efficacy and effectiveness and an essential, obligatory, life-saving step. Blood loss replacement serves the purpose of preventing ischemia/reperfusion toxemia and optimizing tissue oxygenation and microcirculation dynamics. The "physiological classification of HS" dictates the timely management and suits the 'titrated hypotensive resuscitation' tactics and the 'damage control surgery' strategy. In any hypotensive but not yet critical shock, the body's response to a fluid load test determines the cut-off point between compensation and progression between the time for adopting conservative treatment and preparing for surgery or rushing to the theater for rapid bleeding source control. Up to 20% of the total blood volume is given to refill the unstressed venous return volume. In any critical level of shock where, ab initio, the patient manifests signs indicating critical physiology and impending cardiac arrest or cardiovascular accident, the balance between the life-saving reflexes stretched to the maximum and the insufficient distal perfusion (blood, oxygen, and substrates) remains in a liable and delicate equilibrium, susceptible to any minimal change or interfering variable. In a cardiac arrest by exsanguination, the core of the physiological issue remains the rapid restoration of a sufficient venous return, allowing the heart to pump it back into systemic circulation either by open massage via sternotomy or anterolateral thoracotomy or spontaneously after aorta clamping in the chest or in the abdomen at the epigastrium under extracorporeal resuscitation and induced hypothermia. This is the only way to prevent ischemic damage to the brain and the heart. This is accomplishable rapidly and efficiently only by a direct approach, which is a crush laparotomy if the bleeding is coming from an abdominal +/- lower limb site or rapid sternotomy/anterolateral thoracotomy if the bleeding is coming from a chest +/- upper limbs site. Without first stopping the bleeding and refilling the heart, any further exercise is doomed to failure. Direct source control via laparotomy/thoracotomy, with the concomitant or soon following venous refilling, are the two essential, initial life-saving steps.

Low dose of esketamine combined with propofol in painless fibronchoscopy in elderly patients

To explore the effects and safety of low dose of esketamine combined with propofol in elderly patients undergoing fibronchoscopy. Eighty elderly patients who underwent painless fibronchoscopy in our hospital from June 2021 to September 2021 were recruited,and randomly divided into experimental group (esketamine 0.15mg/ kg + propofol 1mg/ kg) and control group (sufentanil 0.1 μg/ kg + propofol 1mg/ kg), with 40 cases in each group. There were significant differences in MAP, HR and SpO2 of T2, T3 and T4 between the experimental and control groups (P < .05). Besides, there were significantly differences on the trend of change between the 2 groups, with a small and relatively stable fluctuation in the experimental group (P < .05). Compared with the control group, the total dosage of propofol in the experimental group was significantly lower, and the number of vasoactive drugs, the incidence of respiratory depression and bronchospasm were significantly lower (P < .05). There was no significant difference in microscopic examination time, wake-up time, visual analogue score, and agitation, mental symptoms, increased secretion, nausea and vomiting, choking cough and laryngeal spasm during awakening period between the 2 groups. The incidence of total adverse reactions in the experimental group were strongly lower than those in control group. (P < .05). Low dose of esketamine combined with propofol can be safely used for fibronchoscopy in elderly patients, with good effects, more stable respiration and circulation, and low incidence of adverse reactions.

Evaluation of the effect of perioperative administration of S(+)-ketamine hydrochloride injection for postoperative acute pain in children: study protocol for a prospective, multicenter, randomized, open-label, parallel-group, pragmatic clinical trial

Background

Inadequate postoperative pain management increases the risk of adverse events after the surgery and aggressive perioperative pain prevention has both short-term and long-term benefits. S(+)-ketamine is an N-methyl-D-aspartic acid (NMDA) receptor antagonist with a strong analgesic effect and can significantly relieve postoperative acute pain and reduce opioid consumption. However, for children, it still needs to be confirmed by large sample clinical studies.

Methods

This is a pragmatic, randomized controlled trial which will evaluate the effect of perioperative administration of S(+)-ketamine hydrochloride injection for postoperative acute pain in children in a pragmatic clinical setting. A total of 3000 children (≤17 years old) undergoing surgery will be included in this protocol. Subjects will be randomized 2:1 to either receive S(+)-ketamine hydrochloride injection or conventional therapy without S(+)-ketamine during the entire perioperative period. The primary endpoints are the area under the receiver operating characteristic (ROC) curve of Face Legs Activity Cry and Consolability (FLACC, 0–7 years old) scale score or Numerical Rating Scale (NRS, 8–17 years old) score within 48 h after surgery, and the consumption of opioids within 48 h after surgery. The secondary endpoints include the time of first use of rescue analgesics after surgery, rescue analgesia rate within 48 h after surgery, anesthesia recovery time, incidence of emergency delirium (for 0-7 years old), changes of anxiety and depression scale scores at 48 h after surgery (for 8-17 years old), incidence of intraoperative adverse events (AEs), and incidence of postoperative AEs and pharmacoeconomic indicators. AEs and serious AEs were recorded to evaluate safety.

Discussion

This trial will be the first pragmatic clinical trial to prospectively assess the effect of perioperative administration of S(+)-ketamine hydrochloride injection for postoperative acute pain in children, which is of great significance to the continuous optimization of clinical anesthesia and analgesia programs for children.

Trial registration

This trial was registered in the U.S. National Institutes of Health ClinicalTrials.gov database (http://clinicaltrials.gov; Registration number: NCT04834427). Registered on 8 April 2021.

Sedative effect and safety of different doses of S-ketamine in combination with propofol during gastro-duodenoscopy in school-aged children: a prospective, randomized study

Background

Propofol combined with opioids can reduce the dosage of propofol and improve the safety of endoscopy. However, there are few studies on propofol combined with S-ketamine in children undergoing gastro-duodenoscopy. We aim to determine the sedative effect and safety of different doses of S-ketamine in combination with propofol in school-aged children undergoing gastro-duodenoscopy.

Methods

This is a prospective, randomized trial. Totally, 120 school-aged children who underwent gastro-duodenoscopy were randomly allocated into Group P, Group S0.3, Group S0.5 and Group S0.7. During induction, children in Group P, Group S0.3, Group S0.5 and Group S0.7 received 0, 0.3 mg.kg−1, 0.5 mg.kg−1 and 0.7 mg.kg−1 S-ketamine, respectively, following 3 mg.kg−1 propofol injection. During gastro-duodenoscopy, 1 mg.kg−1 of propofol was added according to the condition of the children and the BIS (bispectral index) value. The primary outcome was smooth placement rate of the first endoscope insertion. The secondary outcome was the times of additional propofol, the total amount of propofol, adverse events, recovery time, length of PACU (post anesthesia care unit) stay and endoscopist satisfaction.

Results

The smooth placement rate of the first endoscope insertion in Group P, Group S0.3 and Group S0.5 was significantly lower than that in Group S0.7 (16.70%, 34.50%, 50.00% vs. 83.30%, respectively, P < 0.001). The times of additional propofol in Group S0.3 (P = 0.018), Group S0.5 (P = 0.014) and Group S0.7 (P = 0.001) were significantly less than Group P. The total amount of propofol in Group S0.7 was significantly less than Group P (P < 0.001). The incidence of intraoperative hypotension in Group S0.5 and Group S0.7 was low. Group S0.7 had significantly higher incidence of postoperative dizziness (P = 0.003), longer PACU stay (P = 0.018) and higher endoscopist satisfaction (P = 0.001) than Group P. There was no difference in the recovery time among groups.

Conclusion

S-ketamine (0.7 mg.kg−1) in combination with propofol can provide satisfactory sedative effect and reduce the dosage of propofol in school-aged children undergoing gastro-duodenoscopy, but there are higher incidence of postoperative dizziness and longer PACU stay.

Effects of Remimazolam Combined with Esketamine Anesthesia on Circulatory and Respiratory Function during Painless Gastroenteroscopy

Objective

To investigate the effect of applying remimazolam combined with esketamine for anesthesia in painless gastroenteroscopy on patients' circulatory and respiratory function.

Method

In this study, 106 patients who had undergone painless gastroenteroscopy in Xinjiang Production and Construction Corps (XPCC) Hospital between July 2021 and January 2022 were selected as study subjects, which were grouped according to the anesthetic drugs used in the surgery and divided into control group (n = 53 cases) and observation group (n = 53 cases), while those who were anesthetized with propofol + sufentanil during the operation were the control group and those who were anesthetized with remimazolam + esketamine were the observation group. To compare the induction time of anesthesia, patient awakening and recovery time of orientation, circulatory and respiratory function, intraoperative adverse effects, and postoperative complications in the two study groups.

Results

There was no statistical difference in induction of anesthesia, patient awakening, and recovery time of orientation between the two groups (P > 0.05) and no statistical difference in postoperative complications (P > 0.05). The observation group had a better occurrence of local pain at the injection site, circulatory and respiratory function of patients after anesthesia, and intraoperative adverse reactions than the control group (P < 0.05).

Conclusion

Remimazolam combined with esketamine anesthesia has the same advantages of rapid awakening compared with propofol anesthesia. Moreover, it has fewer side effects on patients' circulatory and respiratory functions with fewer adverse effects, as a suitable anesthetic method for painless gastroenteroscopy.

Effective dose of propofol combined with a low-dose esketamine for gastroscopy in elderly patients: A dose finding study using dixon’s up-and-down method

Objective: This study aimed to determine the optimal dose of propofol combined with esketamine to inhibit the response to gastroscope insertion in elderly patients.

Methods: This is a prospective, non-controlled, non-randomized, single-center study. Elderly patients aged 65–80 years were enrolled in the study with the American society of anesthesiologists (ASA) physical status I or II undergoing elective gastroscopy. All patients were administered propofol after an intravenous esketamine at the dosage of 0.3 mg/kg 30 s, the subsequent dose of propofol was determined by the response of the previous patient to gastroscope insertion (choking, body movement, etc.) using Dixon’s up-and-down method. The initial dose of propofol administered to the first elderly patient was 3.0 mg/kg, and the standard ratio of propofol dose in adjacent patients was 0.9. At least six crossover points were obtained before the conclusion of the study. By using Probit analysis the median effective dose (ED₅₀), 95% effective dose (ED₉₅), and the corresponding 95% confidence interval (CI) for propofol were determined.

Results: The study continued until we obtained seven crossover points and 32 elderly patients (17 males and 15 females) were collected. The ED₅₀ of propofol combined with esketamine inhibiting response to gastroscope insertion in elderly patients were found to be 1.479 mg/kg (95% CI 1.331–1.592 mg/kg), and ED₉₅ was found to be 1.738 mg/kg (95% CI 1.614–2.487 mg/kg).

Conclusion: According to the present study, propofol combined with 0.3 mg/kg esketamine is safe and effective for elderly patients undergoing gastroscopy. The ED₅₀ and ED₉₅ doses of propofol inhibiting response to gastroscope insertion in elderly patients when combined with 0.3 mg/kg esketamine were 1.479 and 1.738 mg/kg, respectively, without apparent adverse effects.

S-ketamine administration in pregnant mice induces ADHD- and depression-like behaviors in offspring mice

BACKGROUND

Anesthesia and psychotropic drugs in pregnant women may cause long-term effects on the brain development of unborn babies. The authors set out to investigate the neurotoxicity of S-ketamine, which possesses anesthetic and antidepressant effects and may cause attention deficit hyperactivity disorder (ADHD)- and depression-like behaviors in offspring mice.

METHODS

Pregnant mice were administered with low-, medium-, and high-dose S-ketamine (15, 30, and 60 mg/kg) by intraperitoneal injection for 5 days from gestational day 14-18. At 21 days after birth, an elevated plus-maze test, fear conditioning, open field test, and forced swimming test were used to assess ADHD- and depression-like behaviors. Neuronal amount, glial activation, synaptic function indicated by ki67, and inhibitory presynaptic proteins revealed by GAD2 in the hippocampus, amygdala, habenula nucleus, and lateral hypothalamus (LHA) were determined by immunofluorescence assay.

RESULTS

All the pregnant mice exposed to high-dose S-ketamine administration had miscarriage after the first injection. Both low-dose and medium-dose S-ketamine administration significantly increased the open-arm time and attenuated frozen time in the fear conditioning, which indicates impulsivity and memory dysfunction-like behaviors. Medium-dose S-ketamine administration reduced locomotor activity in the open field and increased immobility time in the forced swimming test, indicating depression-like behaviors. Changes in astrocytic activation, synaptic dysfunction, and decreased inhibitory presynaptic proteins were found in the hippocampus, amygdala, and habenula nucleus.

CONCLUSIONS

These results demonstrate that S-ketamine may lead to detrimental effects, including ADHD-and depression-like behaviors in offspring mice. More studies should be promoted to determine the neurotoxicity of S-ketamine in the developing brain.

Advantages of ketamine in pediatric anesthesia

Although ketamine is primarily used for induction and maintenance of general anesthesia, it also presents sedative, amnestic, anesthetics, analgesic, antihyperalgesia, neuroprotective, anti-inflammatory, immunomodulant, and antidepressant effects. Its unique pharmacodynamics and pharmacokinetic properties allow the use of ketamine in various clinical settings including sedation, ambulatory anesthesia, and intensive care practices. It has also adopted to manage acute and chronic pain management. Clinically, ketamine produces dissociative sedation, analgesia, and amnesia while maintaining laryngeal reflexes, with respiratory and cardiovascular stability. Notably, it does not cause respiratory depression, maintaining both the hypercapnic reflex and the residual functional capacity with a moderate bronchodilation effect. In the pediatric population, ketamine can be administered through practically all routes, making it an advantageous drug for the sedation required setting such as placement of difficult vascular access and in uncooperative and oppositional children. Consequently, ketamine is indicated in prehospital induction of anesthesia, induction of anesthesia in potentially hemodynamic unstable patients, and in patients at risk of bronchospasm. Even more, ketamine does not increase intracranial pressure, and it can be safely used also in patients with traumatic brain injuries. This article is aimed to provide a brief and practical summary of the role of ketamine in the pediatric field.

Efficacy and Safety of Remimazolam Tosilate Combined With Esketamine for Analgesic Sedation in Mechanically Ventilated ICU Patients: A Single-Arm Clinical Study Protocol

Introduction

Patients in the intensive care unit (ICU) frequently experience increased heart rate, blood pressure, and respiration rate as a product of anxiety and restlessness about their condition and treatments. Analgesia and sedation commonly involve benzodiazepines or opioids that lead to respiratory suppression and other adverse reactions. Remimazolam tosilate is a short-acting GABAA receptor agonist with reduced cardiovascular and respiratory inhibition compared to other commonly used benzodiazepines. Esketamine is a non-competitive N-methyl-D-aspartic acid (NMDA) receptor inhibitor that inhibits hyperalgesia and prolongs postoperative analgesia. It also reduces postoperative pain, delirium, and the use and acute tolerance of opioids. This study aims to assess the efficacy and safety of remimazolam tosilate combined with esketamine and sufentanil for sedation and analgesia in mechanically ventilated ICU patients.

Methods and Analysis

This prospective, single-arm, single-center, open-label clinical trial will be conducted from January 2022 to December 2023. The study will include 200 adult patients (≥ 18 years) from Shandong Provincial Hospital (affiliated with Shandong First Medical University) who are mechanically ventilated and admitted to the ICU between 24 and 72 h from the time of ventilation and who are administered analgesia and sedatives. Patients will undergo arterial blood gas analysis before administration. Remimazolam tosilate (0.2 mg/kg) will be injected intravenously within 30 s, followed by continuous infusion at a rate of 0.1 to 0.3 mg/kg/h via micropump. Esketamine (0.25 mg/kg) will be injected intravenously and maintained at 0.15 mg/kg/h, while sufentanil will be maintained at the rate of 0.1 to 0.2 μg/kg/h. The primary study outcome is the overall time required to maintain sedation. Secondary outcomes will include the total dosage used to reach the target sedation level, total mechanical ventilation time, awakening time, length of hospital stay, and incidence of cardiorespiratory-related adverse events and delirium. Adverse events (AEs) will be reported regardless of their relationship to the experimental drugs. AEs associated with adverse drug reactions will be classified as “affirmative correlation,” “possible relevance,” and “unable to determine.” A paired t-test or Wilcoxon signed-rank test will be used to compare the changes of observed indexes before and after treatment. A P &lt; 0.05 will be considered statistically significant.

Ethics and Dissemination

This study was approved by the local ethics committee at Shandong Provincial Hospital affiliatied to Shandong First Medical University. The results of this trial will be disseminated in peer-reviewed journals and at scientific conferences.

Trial Registration

The trial is registered at the Chinese Clinical Trial Registry: ChiCTR2100053106; date of registration: 2021-11-10.

Efficacy and safety of ketamine in mechanically ventilated intensive care unit patients: a scoping review

Objectives: Mechanically ventilated patients account for about one-third of all admissions to the intensive care unit (ICU). Ketamine has been conditionally recommended to aid with analgesia in such patients, with low quality of evidence available to support this recommendation. We aimed to perform a narrative scoping review of the current knowledge of the use of ketamine, with a specific focus on mechanically ventilated ICU patients. Methods: We searched MEDLINE and EMBASE for relevant articles. Bibliographies of retrieved articles were examined for references of potential relevance. We included studies that described the use of ketamine for postoperative and emergency department management of pain and in the critically unwell, mechanically ventilated population. Results: There are few randomised controlled trials evaluating ketamine's utility in the ICU. The evidence is predominantly retrospective and observational in nature and the results are heterogeneous. Available evidence is summarised in a descriptive manner, with a division made between high dose and low dose ketamine. Ketamine's pharmacology and use as an analgesic agent outside of the ICU is briefly discussed, followed by evidence for use in the ICU setting, with particular emphasis on analgesia, sedation and intubation. Finally, data on adverse effects including delirium, coma, haemodynamic adverse effects, raised intracranial pressure, hypersalivation and laryngospasm are presented. Conclusions: Ketamine is used in mechanically ventilated ICU patients with several potentially positive clinical effects. However, it has a significant side effect profile, which may limit its use in these patients. The role of low dose ketamine infusion in mechanically ventilated ICU patients is not well studied and requires investigation in high quality, prospective randomised trials.

S-ketamine alleviates carbon tetrachloride-induced hepatic injury and oxidative stress by targeting the Nrf2/HO-1 signaling pathway

The aim of the present study was to investigate the protective effect of S-ketamine (S-KET) against carbon tetrachloride (CCl4) - induced liver damage and oxidative stress, as well as to elucidate the related underlying mechanisms. Blood was collected to measure biochemical parameters (alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), total bilirubin (TB) and γ-glutamyltransferase (γ-GT)) and the liver was harvested for histopathological analysis of enzymes related to the antioxidant response (malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), and glutathione peroxidase (GSH-PX)). Liver cell apoptosis was evaluated using the TUNEL assay. In addition, the expression levels of apoptosis-related proteins and the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway were detected by Western blot analysis to explore potential mechanisms. S-KET protected the liver from CCl4-induced damage. The changes to the liver biochemical parameters (increased ALT, AST, ALP, TB, and γ-GT) and oxidative stress-related indicators (increased MDA; depleted SOD, GSH, and GSH-PX) induced by CCl4 were inhibited by S-KET. S-Ket also inhibited CCl4-induced cell apoptosis, the changes in expression of related proteins, and blocked CCl4-induced liver injury and oxidative stress via activation of the Nrf2/HO-1 signaling pathway. S-KET effectively protected the liver by inhibition of CCl4-induced damage via upregulation the Nrf2/HO-1 signaling pathway.

Optimum dose of spinal ropivacaine with or without single intravenous bolus of S-ketamine during elective cesarean delivery: a randomized, double-blind, sequential dose-finding study

Background

Maternal hypotension after spinal anaesthesia occurs at a high rate during caesarean delivery and can lead to adverse maternal or foetal outcomes. The aim of this study was to determine the optimal dose of spinal ropivacaine for caesarean section with or without intravenous single bolus of S-ketamine and to observe the rates of hypotension associated with both methods.

Methods

Eighty women undergoing elective caesarean delivery were randomly allocated into either a ropivacaine only or ropivacaine with intravenous S-ketamine group. If the upper sensory level of the patient reached T6 and the visual analogue scale (VAS) scores remained below 3 points before delivery, the next patient had a 1/9th chance of receiving a lower dose or an 8/9th chance of receiving the same dose as the previous patient. If the patient had VAS scores of more than 2 points or needed an extra epidural rescue bolus before delivery, a higher dose was used for the next patient. The primary outcome was the successful use of spinal ropivacaine to maintain patient VAS score of < 3 points before delivery and the incidence of post-spinal hypotension in both groups. Secondary outcomes included the rates of hypotension-related symptoms and interventions, upper sensory level of anaesthesia, level of sedation, neonatal outcomes, Edinburgh Postnatal Depression Scale scores at admission and discharge, and post-operative analgesic effect. The 90% effective dose (ED90) and 95% confidence interval (95% CI) were estimated by isotonic regression.

Results

The estimated ED90 of ropivacaine was 11.8 mg (95% CI: 11.7–12.7) with and 14.7 mg (95% CI: 14.6–16.0) without intravenous S-ketamine, using biased coin up-down sequential dose-finding method. The rates of hypotension and associated symptoms were significantly lower in S-ketamine group than in the ropivacaine only group.

Conclusions

A spinal dose of ropivacaine 12 mg with a single intravenous 0.15 mg/kg bolus dose of S-ketamine may significantly reduce the risk of hypotension and induce sedation before delivery. This method may be used with appropriate caution for women undergoing elective caesarean delivery and at a high risk of hypotension or experiencing extreme nervousness.

Trial registration

http://www.chictr.org.cn (ChiCTR2000040375; 28/11/2020).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-04229-y.

The optimal dose of oral midazolam with or without intranasal S-ketamine for premedication in children: a randomised, double blinded, sequential dose-finding trial

BACKGROUND

Oral administration of midazolam syrup is one of the most favorable methods of premedication, the optimal dose of midazolam and midazolam with S-ketamine for preschool children has not been determined. This prospective, double-blind, randomized, sequential dose-finding study was designed to estimate the 90% effective doses of oral midazolam with and without intranasal S-ketamine in a grade III child medical center.

METHODS

Eighty successive children were recruited and randomly allocated to midazolam group and midazolam with S-ketamine group. The initial oral doses of midazolam were 0.25 mg/kg in both groups, and the dose of midazolam for the next child was based on the response of the preceding child as the biased coin up-and-down designed. The primary outcome was parental separation anxiety score = 1 throughout the period of transferring from premedication center to the operation room 30 min after premedication. Secondary outcomes were the preoperative and post-operative observations. Finally, the 90% effective dose and 95% confidence intervals were estimated by isotonic regression.

RESULTS

The 90% effective dose of oral midazolam or oral midazolam with intranasal S-ketamine was 0.461 mg/kg (95% confidence interval: 0.425-0.488) and 0.253 mg/kg (95% confidence interval: 0.242-0.278), respectively. Oral midazolam with intranasal S-ketamine was quicker onset (8.9±3.8 vs. 19.7±7.4 min, P<0.001), had less incidence of behavioral changes (7.5% vs. 32.5%, P=0.010) and faster recovery (21.6±14.1 vs. 31.6±13.5 min, P=0.002) than solely oral midazolam.

CONCLUSIONS

A suggestion of oral midazolam 0.3 mg/kg with intranasal small dose of S-ketamine could be used as premedication for preschool children.

TRIAL REGISTRATION

Chinese Clinical Trial Registry.

The use of esketamine sedation in the emergency department for manipulation of paediatric forearm fractures: A 5 year study

The purpose of this study is to assess the use of esketamine as procedural sedation for the reduction of paediatric forearm fractures in the emergency department (ED). A retrospective analysis was undertaken of forearm fractures between 1^st January 2012 to 31^st December 2016 which were treated with manipulation in ED using esketamine sedation. Patient demographics and fracture configuration were collected. Patient radiographs were evaluated and cast index calculated. 151 patients (103 male, 48 female) were included (average age of 8.5 [1 to 15]). Four (2.6%) patients were lost to final follow up. 11 (7%) fractures were not accepted after initial manipulation and required formal surgical management under general anaesthetic. At one week follow up, a further 5 (3%) fractures displaced requiring operative management. 100% of patients who slipped at one week had a cast index greater than 0.8 [average 0.86, 95% CI 0.80-0.92]. At final follow up successful reduction was achieved in 89.1% (131/144) of patients. No adverse events occurred following administration of esketamine. This study provides evidence that manipulation of paediatric forearm fractures using esketamine as procedural sedation in the ED is comparable to other methods in achieving acceptable outcomes. This is in addition to the potential for cost savings. However, future studies formally assessing cost effectiveness and patient outcomes are needed.

Repurposing Potential of Ketamine: Opportunities and Challenges

Ketamine is a noncompetitive antagonist of the N-methyl-D-aspartate (NMDA) receptor which also interacts with various other receptors that account for its myriad actions. Originally approved as a general anesthetic, it is being explored to be repurposed for numerous other indications such as depressive disorders, suicidal ideation, substance-use disorders, anxiety disorders, chronic pain, refractory status epilepticus, and bronchial asthma exacerbations. Numerous trials are ongoing for the same. The nasal spray of esketamine, a more potent S (+) enantiomer of ketamine, has been approved by the United States Food and Drug Administration (USFDA) for treatment-resistant depression along with the oral antidepressants. However, there are concerns about its safety on long term use, given its psychedelic effects and potential abuse. In this review, we discuss repurposing ketamine for potential therapeutic use and about the safety concerns related to ketamine and esketamine.

Topical Pharyngeal Lidocaine Reduces Respiratory Adverse Events During Upper Gastrointestinal Endoscopies Under Ketamine Sedation in Children

BACKGROUND

Upper gastrointestinal endoscopies (UGEs) performed under ketamine sedation may increase the risk of respiratory adverse events (RAEs) due to pharyngeal stimulation. Topical lidocaine prevents general anesthesia-induced laryngospasm.

OBJECTIVE

Our objective was to determine whether topical lidocaine may reduce the incidence of RAEs induced by pharyngeal stimulation in UGEs performed on children sedated with ketamine.

METHODS

We conducted a single-center prospective study. We included every patient admitted for an elective diagnostic UGE under ketamine sedation who received lidocaine prior to the technique. Patients requiring any other medication were excluded. Our main outcome measure was the number of desaturation episodes. We then compared these results with those obtained in an historic group who did not receive topical lidocaine, in which we registered a total of 54 desaturation episodes.

RESULTS

In total, 88 children (52.3% boys) were included. The median age was 7 years [interquartile range (IQR) 3-11]. The mean duration of the procedure was 6.5 ± 2.4 min, and the median initial ketamine dose was 1.76 mg/kg (IQR 1.56-2.03). The total number of desaturation episodes was 3 (3.4%), and two of these occurred prior to the introduction of the endoscope. This result represents a lower incidence than in previously reported series, and a significant decrease (p < 0.0001) with respect to the 54 RAEs registered in the historic group of 87 children.

CONCLUSIONS

Topical lidocaine premedication significantly reduced the incidence of RAEs in children during UGEs under ketamine sedation. Our findings should be confirmed by a double-blind randomized controlled trial.