Meta-Analysis: Hemodynamic Responses to Sub-anesthetic Doses of Ketamine in Patients With Psychiatric Disorders

Effect of esketamine on haemodynamic fluctuations in patients undergoing hysteroscopic surgery: A prospective, double-blind randomized clinical trial

AIMS

We explored whether esketamine anesthesia during hysteroscopic surgery can reduce intraoperative hemodynamic fluctuations and improve patient benefit.

METHODS

A total of 170 patients undergoing hysteroscopic surgery were enrolled, and 151 patients were finally included in the analysis, among which 19 used vasoactive drugs during surgery. Patients were randomly assigned to either the esketamine anesthesia group (E group) or the sufentanil anesthesia group (S group). The primary outcomes were blood pressure and heart rate during the surgery. Secondary outcomes included resistance to laryngeal mask insertion, demand for propofol and remifentanil, nausea and vomiting, Richmond Agitation and Sedation Scale (RASS), dizziness and pain intensity after resuscitation, vasoactive medication treatment, hospitalization time and expenses.

RESULTS

E group had a more stable heart rate, systolic blood pressure, diastolic blood pressure and mean blood pressure than the S group (p < 0.001). Patients in E group had a higher demand for propofol (p < 0.001) but better RASS scores (p < 0.001) after resuscitation. The incidence of intraoperative vasoactive medication use was higher in the S group (18.4% vs. 6.7%, p = 0.029). There were no statistically significant differences in terms of resistance to laryngeal mask insertion, remifentanil demand, time required for resuscitation, postoperative pain, dizziness, nausea or vomiting.

CONCLUSIONS

Compared with sufentanil, esketamine-induced anesthesia during hysteroscopic surgery can reduce intraoperative hemodynamic fluctuations and the incidence of intraoperative vasoactive medication. Although esketamine-induced anesthesia may increase the demand for propofol during surgery, it does not affect the anesthesia recovery time and the quality of patient recovery is better.

Psychedelics and the treatment of eating disorders: considerations for future research and practice

Recent trials have shown promising results for the use of psychedelic-assisted therapies in treating severe refractory psychiatric illnesses, and there has been growing interest in examining the effectiveness of these therapies in treating eating disorders. To move forward in a safe, ethically sound, and scientifically rigorous manner, the field must address critical considerations. In this Comment article, we outline important risks and ethical considerations, along with methodological aspects that require careful consideration in the design of psychedelic-assisted therapy trials. We conclude by providing provisional guidelines for clinical research trials to help shape the future of this work, with the aim of investigating and employing the use of psychedelics for treating eating disorders in a manner that protects clients and research participants while maximizing methodological rigour.

Diurnal variation of postoperative delirium in elderly patients undergoing esketamine anesthesia for elective noncardiac surgery: a randomized clinical trial

BACKGROUND

Postoperative delirium (POD) is a serious and common complication. The aim of present study is to investigate the diurnal variation of POD and the effects of esketamine in elderly patients.

METHODS

A randomized, double-blind, placebo-controlled clinical trial with factorial design was conducted. Patients (aged 65 to 85 years) with normal Mini-Mental State Examination (MMSE) score were stratified by age (≤70 vs. >70) and American Society of Anesthesiologists physical status classification (Ⅱ vs. Ⅲ), then randomly assigned to either morning (08:00-12:00) or afternoon (14:00-18:00) noncardiac operation under general anesthesia with or without esketamine administration (0.2 mg/kg). The primary outcome was the incidence of POD (3-Minute Diagnostic Interview for Confusion Assessment Method-defined Delirium, 3D-CAM) on postoperative days 1, 3, and 7. The secondary outcomes were the scores of MMSE and Hospital Anxiety and Depression Scale. The intention-to-treat analysis of the outcomes were performed by generalized estimating equation.

RESULTS

Six patients who did not receive an intervention because of canceled operation were excluded after randomization. The datasets containing 426 cases were analyzed following the intention-to-treat principle after handling missing data via multiple imputation method. The incidence of POD declined from about 55% on postoperative day 1 to 31 and 18% on postoperative days 3 and 7, respectively. Afternoon operation [B=-0.583, OR (95% CI) 0.558 (0.319-0.976); P=0.041], but not esketamine, significantly decreased the incidence of POD. Both esketamine and operation time failed to significantly affect MMSE, HAD, and NRS score. There was no interaction among operation time, esketamine, and follow up time.

CONCLUSION

Elderly patients undergoing elective noncardiac surgery in the afternoon displayed lower POD incidence than those operated in the morning. A single low-dose of esketamine before general anesthesia induction failed to significantly decrease the risk of POD but decrease the risk of intraoperative hypotension and emergence agitation.

Effect of esketamine on hypotension in women with preoperative anxiety undergoing elective cesarean section: a randomized, double-blind, controlled trial

To investigate the effect of low-doses esketamine on spinal anesthesia-induced hypotension in women with preoperative anxiety undergoing elective cesarean section, the randomized controlled trial enrolled 120 women aged 18-35 years who preoperative State-Trait Anxiety Inventory State scores > 40, conducted from September 2022 to August 2023 in Xuzhou Central Hospital, China. Women in the esketamine group received a single intravenous injection of 0.2 mg/kg esketamine after sensory block level achieved. The incidence of hypotension in the esketamine group was significantly lower than the control group at T2 (10% [6 of 60]; P < 0.001), T3 (5.0% [3 of 60]; P = 0.007) and T4(5.0% [3 of 60]; P = 0.004). Despite being higher in the esketamine group, the overall rates of hypertension (11.7% [7 of 60]; P = 0.186), tachycardia (23.3% [14 of 60]; P = 0.246), and bradycardia (0.0% [0 of 60]; P = 0.079) were no significantly difference between the two groups. STAI-S scores was significantly lower in the esketamine group (mean [SD] 37.52[7.14]) than in the control group (mean [SD] 41.03[9.66], P = 0.39) in postoperative day 1. Spinal anesthesia combined with intravenous low-doses esketamine infusion can significantly reduce the incidence of hypotension in women with preoperative anxiety undergoing elective cesarean section.

Esketamine in depression: putative biomarkers from clinical research

The discovery of racemic (R, S)-ketamine as a rapid-acting antidepressant and the subsequent FDA approval of its (S)-enantiomer, esketamine, for treatment-resistant depression (TRD) are significant advances in the development of novel neuropsychiatric therapeutics. Esketamine is now recognized as a powerful tool for addressing persistent symptoms of TRD compared to traditional oral antidepressants. However, research on biomarkers associated with antidepressant response to esketamine has remained sparse and, to date, has been largely extrapolated from racemic ketamine studies. Genetic, proteomic, and metabolomic profiles suggest that inflammation and mitochondrial function may play a role in esketamine's antidepressant effects, though these preliminary results require verification. In addition, neuroimaging research has consistently implicated the prefrontal cortex, striatum, and anterior cingulate cortex in esketamine's effects. Esketamine also shows promise in perioperative settings for reducing depression and anxiety, and these effects appear to correlate with increased peripheral biomarkers such as brain-derived neurotrophic factor and serotonin. Further indications are likely to be identified with the continued repurposing of racemic ketamine, providing further opportunity for biomarker study and mechanistic understanding of therapeutic effects. Novel methodologies and well-designed biomarker-focused clinical research trials are needed to more clearly elucidate esketamine's therapeutic actions as well as biologically identify those most likely to benefit from this agent, allowing for the improved personalization of antidepressant treatment.

Ketamine for mood disorders, anxiety, and suicidality in children and adolescents: a systematic review

Mood disorders, anxiety, and suicidality in youth are increasing and rapid-acting treatments are urgently needed. One potential is ketamine or its enantiomer esketamine, which was FDA approved in 2019 to treat major depressive disorder with suicidality in adults. This systematic review evaluated the evidence for the clinical use of ketamine to treat mood disorders, anxiety, and suicidality in youth. The PRISMA guidelines were used, and a protocol registered prospectively ( https://osf.io/9ucsg/ ). The literature search included Pubmed/MEDLINE, Ovid/MEDLINE, Scopus, CINAHL, PsychInfo, and Google Scholar. Trial registries and preprint servers were searched, and authors contacted for clarification. Studies reported on the clinical use of ketamine to treat anxiety, depression, bipolar disorder, or suicidality in youth ≤19 years old and assessed symptoms before and after ketamine use. Study screening and data extraction were conducted independently by 2-4 authors. Safety, tolerability, and efficacy data were collected. The Cochrane Risk of Bias guidelines assessed the quality of the evidence. Twenty-two published reports based on 16 studies were identified: 7 case studies, 6 observational studies, 3 randomized trials, and 6 secondary data analyses. Studies reported immediate improvements in depression, anxiety, and suicidality. Improvements were maintained for weeks-months following treatment. Ketamine was well-tolerated with the most common side effects being dizziness, nausea, and mild dissociation. Transient hemodynamic changes were reported, all of which resolved quickly and did not require medical intervention. Initial evidence suggests ketamine is safe and may be effective for mood disorders, anxiety, and suicidality in youth. Further randomized trials are warranted.

Effects of S-ketamine on Postoperative Recovery Quality and Inflammatory Response in Patients Undergoing Modified Radical Mastectomy

INTRODUCTION

S-ketamine plays an important role in reducing postoperative pain, but its impact on the quality of recovery in breast cancer has not been clarified. We designed this trial to explore the effects of s-ketamine on the quality of postoperative recovery and inflammatory response in modified radical mastectomy.

METHODS

A total of 138 patients were randomly assigned to group C (group control), group K1 (group of s-ketamine dose 1) and group K2 (group of s-ketamine dose 2). Groups K1 and K2 were given 0.1 mg/kg, 0.2 mg/kg s-ketamine intravenous (IV) after induction, followed by 0.1 mg/kg/h or 0.2 mg/kg/h continuous intravenous infusion, respectively. Group C received the same volume of saline. A 40-item Quality of Recovery Questionnaire (QoR-40) was used to assess the quality of recovery at 24 h postoperatively. Changes in inflammatory markers, nociceptive thresholds, and the occurrence of adverse events were recorded at 24 h postoperatively.

RESULTS

The QoR-40 scores at 24 h postoperatively were higher in group K2 [182.00 (179.00-185.00)] compared to group K1 [174.00 (169.50-180.50)] and group C [169.00 (163.75-174.25)] (group K2 vs. group K1, P < 0.001; group K2 vs. group C, P < 0.001). At 24 h postoperatively, the neutrophil count, NLR (neutrophil-lymphocyte ratio), and CRP (C-creative protein) were all significantly lower in group K2 than group C(P < 0.05), no differences were observed between group K1 and C(P > 0.05), group K1 and K2(P > 0.05), respectively. There was no significant difference in the incidence of adverse effects among the three groups (P > 0.05).

CONCLUSIONS

A high dose of s-ketamine improved the quality of recovery at 24 h after surgery, as well as alleviated the inflammatory response without increasing the incidence of adverse effects.

The Montreal model: an integrative biomedical-psychedelic approach to ketamine for severe treatment-resistant depression

Background

Subanesthetic ketamine has accumulated meta-analytic evidence for rapid antidepressant effects in treatment-resistant depression (TRD), resulting in both excitement and debate. Many unanswered questions surround ketamine's mechanisms of action and its integration into real-world psychiatric care, resulting in diverse utilizations that variously resemble electroconvulsive therapy, conventional antidepressants, or serotonergic psychedelics. There is thus an unmet need for clinical approaches to ketamine that are tailored to its unique therapeutic properties.

Methods

This article presents the Montreal model, a comprehensive biopsychosocial approach to ketamine for severe TRD refined over 6 years in public healthcare settings. To contextualize its development, we review the evidence for ketamine as a biomedical and as a psychedelic treatment of depression, emphasizing each perspectives' strengths, weaknesses, and distinct methods of utilization. We then describe the key clinical experiences and research findings that shaped the model's various components, which are presented in detail.

Results

The Montreal model, as implemented in a recent randomized clinical trial, aims to synergistically pair ketamine infusions with conventional and psychedelic biopsychosocial care. Ketamine is broadly conceptualized as a brief intervention that can produce windows of opportunity for enhanced psychiatric care, as well as powerful occasions for psychological growth. The model combines structured psychiatric care and concomitant psychotherapy with six ketamine infusions, administered with psychedelic-inspired nonpharmacological adjuncts including rolling preparative and integrative psychological support.

Discussion

Our integrative model aims to bridge the biomedical-psychedelic divide to offer a feasible, flexible, and standardized approach to ketamine for TRD. Our learnings from developing and implementing this psychedelic-inspired model for severe, real-world patients in two academic hospitals may offer valuable insights for the ongoing roll-out of a range of psychedelic therapies. Further research is needed to assess the Montreal model's effectiveness and hypothesized psychological mechanisms.

Efficacy and adverse effects of ketamine versus electroconvulsive therapy for major depressive disorder: A systematic review and meta-analysis

BACKGROUND

ECT is considered the fastest and most effective treatment for TRD. Ketamine seems to be an attractive alternative due to its rapid-onset antidepressant effects and impact on suicidal thoughts. This study aimed to compare efficacy and tolerability of ECT and ketamine for different depression outcomes (PROSPERO/CRD42022349220).

METHODS

We searched MEDLINE, Web of Science, Embase, PsycINFO, Google Scholar, Cochrane Library and trial registries, which were the ClinicalTrials.gov and the World Health Organization's International Clinical Trials Registry Platform, without restrictions on publication date.

SELECTION CRITERIA

randomized controlled trials or cohorts comparing ketamine versus ECT in patients with TRD.

RESULTS

Eight studies met the inclusion criteria (of 2875 retrieved). Random-effects models comparing ketamine and ECT regarding the following outcomes were conducted: a) reduction of depressive symptoms severity through scales, g = -0.12, p = 0.68; b) response to therapy, RR = 0.89, p = 0.51; c) reported side-effects: dissociative symptoms, RR = 5.41, p = 0.06; nausea, RR = 0.73, p = 0.47; muscle pain, RR = 0.25, p = 0.02; and headache, RR = 0.39, p = 0.08. Influential & subgroup analyses were performed.

LIMITATIONS

Methodological issues with high risk of bias in some of the source material, reduced number of eligible studies with high in-between heterogeneity and small sample sizes.

CONCLUSION

Our study showed no evidence to support the superiority of ketamine over ECT for severity of depressive symptoms and response to therapy. Regarding side effects, there was a statistically significant decreased risk of muscle pain in patients treated with ketamine compared to ECT.

Psychedelics in the treatment of unipolar and bipolar depression

This is a narrative review about the role of classic and two atypical psychedelics in the treatment of unipolar and bipolar depression. Since the 1990s, psychedelics experience a renaissance in biomedical research. The so-called classic psychedelics include lysergic acid diethylamide (LSD), psilocybin, mescaline and ayahuasca. Characteristic effects like alterations in sensory perception, as well as emotion- and self-processing are induced by stimulation of serotonin 2A receptors in cortical areas. The new paradigm of psychedelic-assisted psychotherapy suggests a therapeutic framework in which a safely conducted psychedelic experience is integrated into a continuous psychotherapeutic process. First randomized, controlled trials with psilocybin show promising efficacy, tolerability, and adherence in the treatment of unipolar depression. On the other hand, classic psychedelics seem to be associated with the induction of mania, which is an important issue to consider for the design of research and clinical protocols. So called atypical psychedelics are a heterogeneous group with overlapping subjective effects but different neurobiological mechanisms. Two examples of therapeutic value in psychiatry are 3,4-methyl​enedioxy​methamphetamine (MDMA) and ketamine. Since 2020 the ketamine enantiomer esketamine has been granted international approval for treatment-resistant unipolar depression, and also first evidence exists for the therapeutic efficacy of ketamine in bipolar depression. Whether psychedelics will fulfil current expectations and find their way into broader clinical use will depend on future rigorous clinical trials with larger sample sizes. A well-considered therapeutic and legal framework will be crucial for these substances to create new treatment settings and a potential paradigm shift.

Key considerations for the use of ketamine and esketamine for the treatment of depression: focusing on administration, safety, and tolerability

INTRODUCTION

Racemic ketamine, a derivative of phencyclidine, has been used as a dissociative anesthetic since 1970. In 2000, the first randomized controlled trial showed a rapid relief of depressive symptoms. Since then, intravenous ketamine and intranasal S-ketamine have been validated for the treatment of depression and suicidal ideation following dose-response and double-blind placebo-controlled clinical trials. In clinical practice, after dose titration and with repeated treatments, patients may experience approximately 2-3 weeks of symptomatic relief from depression.

AREAS COVERED

Areas covered in this narrative review include mechanism of action, dosing, safety, and tolerability. Some attention is paid to the possibility of R-ketamine as a future antidepressant.

EXPERT OPINION

We recommend further investigation into treatment dosing and frequency strategies as well as approaches that prolong the therapeutic effects. The current fixed dosing of esketamine for obese individuals may be insufficient. Additional investigation into co-administration with somatic and neuromodulation treatments needs investigation. Finally, continuing to monitor research subjects and patients long-term for the emergence of adverse effects on cognition or other organ systems is critical.

Emerging roles of long non-coding RNA in depression

Depression is the second most common psychiatric disorder, affecting more than 340 million people of all ages worldwide. However, the mechanisms underlying the development of depression remain unclear, and existing antidepressants may cause clinical dependence and toxic side effects. Recently, emerging evidence from the fields of neuroscience, genetics, and genomics supports the modulatory role of long non-coding RNA (lncRNA) in depression. LncRNAs may mediate the pathogenesis of depression through multiple pathways, including regulating neurotransmitters and neurotrophic factors, affecting synaptic conduction, and regulating the ventriculo-olfactory neurogenic system. In addition, relying on genome-wide association study and molecular biological experiment, the possibility of lncRNA as a potential biomarker for the differential diagnosis of depression and other mental illnesses, including schizophrenia and anxiety disorders, is gradually being revealed. Thus, it is important to explore whether lncRNAs are potential therapeutic targets and diagnostic biomarkers for depression. Here, we summarize the genesis and function of lncRNAs and discuss the aberrant expression and functional roles of lncRNAs in the development, diagnosis, and therapy of depression, as well as the deficiencies and limitations of these studies. Moreover, we established a lncRNA-miRNA-mRNA-pathway-drug network of depression through bioinformatics analysis methods to deepen our understanding of the relationship between lncRNA and depression, promoting the clinical application of epigenetic research.

Ketamine and esketamine for crisis management in patients with depression: Why, whom, and how?

Currently, only a limited number of interventions can rapidly relieve depressive symptomatology in patients with major depressive disorder or bipolar disorder experiencing extreme distress. Such crises, especially when suicide attempt or ideation is involved, are a major risk factor of suicide. Ketamine, a N-methyl-d-aspartate glutamate receptor antagonist, and its enantiomer esketamine rapidly reduce depressive symptoms in depressed patients with current suicidal ideation. Recently, esketamine has been approved for use in patients with depression at risk of suicide and for psychiatric emergency by major medical agencies in the United States and Europe, whereas ketamine is increasingly used off-label. However, there is currently limited guidance on why, when, and how to use these drugs in patients with depression to treat a crisis. In this review article, we provide a succinct overview of the cellular and molecular mechanisms of action of ketamine and esketamine, and of the functional brain changes following their administration. We also summarize the major clinical studies on ketamine and esketamine efficacy in patients experiencing a crisis (generally, suicidal ideation), and propose a profile of patients who can benefit most from such drugs, on the basis of neurobiological and clinical observations. Finally, we describe the administration mode, the efficacy and tolerability profiles, the side effect management, possible concomitant treatments and the issue of deprescribing.

Non-parenteral Ketamine for Depression: A Practical Discussion on Addiction Potential and Recommendations for Judicious Prescribing

Intravenous (IV) ketamine is increasingly used off-label at subanesthetic doses for its rapid antidepressant effect, and intranasal (IN) esketamine has been recently approved in several countries for treating depression. The clinical utility of these treatments is limited by a paucity of publicly funded IV ketamine and IN esketamine programs and cost barriers to private treatment programs, as well as the drug cost for IN esketamine itself, which makes generic ketamine alternatives an attractive option. Though evidence is limited, use of non-parenteral racemic ketamine formulations (oral, sublingual, and IN) may offer more realistic access in less rigidly supervised settings, both for acute and maintenance treatment in select cases. However, the psychiatric literature has repeatedly cautioned on the addictive potential of ketamine and raised caution for both less supervised and longer-term use of ketamine. To date, these concerns have not been discussed in view of available evidence, nor have they been discussed within a broader clinical context. This paper examines the available relevant literature and suggests that ketamine misuse risks appear not dissimilar to those of other well-established and commonly prescribed agents with abuse potential, such as stimulants or benzodiazepines. As such, ketamine prescribing should be considered in a similar risk/benefit context to balance patient access and need for treatment with concern for potential substance misuse. Our consortium of mood disorder specialists with significant ketamine prescribing experience considers prescribing of non-parenteral ketamine a reasonable clinical treatment option in select cases of treatment-resistant depression. This paper outlines where this may be appropriate and makes practical recommendations for clinicians in judicious prescribing of non-parenteral ketamine.