Effect of S-ketamine administered at the end of anesthesia on emergence delirium in preschool children undergoing tonsillectomy and/or adenoidectomy

The Impact of Preoperative Low-Dose Esketamine and Dexmedetomidine Nasal Administration on the Emergence Delirium in Children Undergoing Fiber Bronchoscopy: A Prospective Randomized Controlled Trial

OBJECTIVE

This study aimed to investigate the effects of preoperative low-dose esketamine and dexmedetomidine nasal administration on the incidence of postoperative emergence delirium in children undergoing fiber bronchoscopy.

METHODS

A total of 129 patients, of any gender, aged 1 to 6 years, with ASA grades I and II, who were scheduled for fiber bronchoscopy, were randomly divided into three groups (n = 43) using a random number table method: 1.0 mg/kg of esketamine, 1.0 μg/kg of dexmedetomidine, and an equal volume of normal saline (group control). The respective dose of the drug or normal saline was rapidly instilled through both nostrils using a 1-mL syringe. The primary outcome measure was the incidence of emergence delirium. The secondary outcome measures included postoperative pain intensity, time to awaken and open eyes in the postanesthesia care unit, incidence of postoperative adverse behavior, hemodynamics, and duration of stay in the postanesthesia care unit.

RESULTS

A total of 126 patients completed the study, and compared with the group control (48.78%), the 1.0 mg/kg esketamine (7.14%) and 1.0 μg/kg dexmedetomidine (18.6%) had a lower incidence of postoperative emergence delirium ( P < 0.01), as well as lower postoperative pain intensity ( P < 0.01). However, compared with the group control, the 1.0 μg/kg dexmedetomidine had a prolonged time to awaken and open eyes in the postanesthesia care unit ( P < 0.05). The duration of hemodynamics, oral secretion volume, and stay in the postanesthesia care unit were similar among the three groups.

CONCLUSIONS

The findings suggest that low-dose esketamine and dexmedetomidine can reduce the incidence of emergence delirium.

Perioperative management of pediatric patients with obstructive sleep apnea syndrome presenting for adenotonsillectomy

PURPOSE OF REVIEW

The prevalence and severity of pediatric obstructive sleep apnea syndrome (OSAS) is increasing, and patients with severe OSAS are at higher risk for perioperative adverse events because of an increased sensitivity to opioid medications. This review highlights new strategies for perioperative medication management for children presenting for adenotonsillectomy.

RECENT FINDINGS

Fewer than 10% of patients presenting for adenotonsillectomy have undergone testing to determine the severity of their OSAS, despite cost-effective and practical diagnostic alternatives to polysomnography, such as nocturnal oximetry. With an increasing incidence of severe OSAS, recent research is focusing on opioid-sparing perioperative management including the use of alternative surgical techniques, regional anesthesia, and use of nonsteroidal anti-inflammatory medications that provide optimal analgesia with minimal adverse complications.

SUMMARY

Severe OSAS increases perioperative risks for pediatric patients, but diagnostic techniques that stratify OSAS severity are underutilized preoperatively, leading to a lack of information on how best to care for patients on the day of surgery. Nonopioid analgesic adjuncts are becoming more common, improving safety for this patient population.

Efficacy of intranasal dexmedetomidine-esketamine sedation for pediatric acceptance of facemask: single-center, double-blind, randomized, controlled trial

OBJECTIVE

We compare the efficacy of intranasal dexmedetomidine (DEX) and DEX-esketamine sedation on pediatric acceptance of face mask.

METHODS

This single-center double-blind randomized controlled study was conducted at a tertiary hospital affiliated with Shanghai Jiao Tong University. Ninety children aged 1 year to 6 years old and scheduled for elective surgery were randomly allocated in a 1:1 ratio into receiving DEX alone (n = 45) and DEX-esketamine (n = 45). DEX and esketamine were used intranasally at doses of 2 µg/kg and 2.0 mg/kg respectively. Children were assessed by an attending anesthesiologist with modified observer's assessment of alertness and sedation (MOAA/S), pediatric separation anxiety scale (PSAS) and mask acceptance scale (MAS). Perioperative adverse events (bradycardia, hypotension, hypoxia, emergence delirium etc.) were recorded.

RESULTS

Of 95 patients enrolled, 90 completed the study. The proportion of children who accepted facemask was significantly higher in the DEX-esketamine group compared to the DEX group (86.7% (39/45) vs. 62.2% (28/45), p = 0.008). Within 30 min after intranasal administration of agents, PSAS scores were similar between the two groups. Children in the DEX group were easily aroused when repositioned from the transferring bed to the operation table. In contrast, those in the DEX-esketamine group maintained a stable level of sedation (MOAA/S scores, median [25th- 75th interquartile range], 1 [1, 1] for DEX-esketamine vs. 2 [1, 4] for DEX, p < 0.001). Furthermore, subgroup analysis found that DEX-esketamine provided better facemask acceptance in children with high anxiety (PSAS ≥ 3). There were no significant differences in perioperative heart rate, noninvasive blood pressure and percutaneous arterial oxygen saturation between the two groups. Postoperative extubation time and perioperative adverse events were also comparable between the groups (all p > 0.05).

CONCLUSIONS

For preoperative sedation, combination of DEX with esketamine improved mask acceptance than dexmedetomidine alone, likely due to its superior anxiolytic effect in children with high anxiety.

TRIAL REGISTRATION

This study was registered in the Chinese Clinical Trial Register (registration no. ChiCTR2400087873, registration date on 6/8/2024).

Comparative evaluation of intravenous versus intranasal dexmedetomidine on emergence delirium and hemodynamics in pediatric patients undergoing adenotonsillectomy: a randomized controlled trial

Background

Dexmedetomidine effectively prevents emergence delirium in children. However, intravenous dexmedetomidine is frequently associated with hemodynamic instability and delayed recovery. Intranasal dexmedetomidine has been proposed as a method of reducing these side effects. This study aimed to evaluate the effects of intranasal versus intravenous dexmedetomidine on emergence recovery and hemodynamics in children undergoing adenotonsillectomy.

Methods

A total of 139 children, aged 3-10 years, who were scheduled for elective adenotonsillectomy were randomly assigned to receive intravenous dexmedetomidine (IV DEX group) or intranasal dexmedetomidine (IN DEX group), or saline (control group) after anesthesia induction. The primary outcome was the highest score on the pediatric anesthesia emergence delirium (PAED) score during the first 30 min after awakening. Secondary outcomes included the perioperative blood pressure and heart rate, time to awakening, postoperative pain score, and length of post-anesthesia care unit (PACU) stay.

Results

The highest PAED and pain scores were significantly lower in the IV and IN DEX groups than those in the control group during the first 30 min after awakening. However, no significant differences were observed between the IV and IN DEX groups. Notably, patients in the IN DEX group exhibited a significantly lower PAED score at 2 h and lower pain scores at 2, 4, and 6 h postoperatively than those in the IV DEX group. Patients in the IV DEX group exhibited a significantly longer awakening time and length of PACU stay than those in the IN DEX and control groups. In the IV DEX group, the heart rate was significantly lower perioperatively than at baseline, while this effect was not observed in the IN DEX group.

Conclusion

Both intravenous and intranasal administration of dexmedetomidine after induction of anesthesia effectively improved emergence delirium and pain intensity in children undergoing adenotonsillectomy. Intranasal administration of dexmedetomidine provided more stable hemodynamics and more prolonged analgesia and sedation than intravenous infusion of dexmedetomidine.

Clinical Trial Registration

https://www.chictr.org.cn/showproj.html?proj=180658.

Effect of perioperative esketamine use on emergency delirium in children undergoing tonsillectomy and adenoidectomy: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Emergence delirium(ED) is a common postoperative complication in children undergoing tonsillectomy and adenoidectomy under general anesthesia. There is no high-quality evidence on the relationship between esketamine and ED. The systematic review and meta-analysis was performed to investigate the effect of perioperative esketamine use on ED in children undergoing tonsillectomy and adenoidectomy.

METHOD

We searched Embase, The Cochrane Library, PubMed, MEDLINE, Web of Science, China National Knowledge Infrastructure (CNKI), WanFang, VIP, and SinoMed from inception to 1 September, 2024. Two evaluators identified randomized controlled trials comparing perioperative use of esketamine with placebo or other drugs in children undergoing tonsillectomy and adenoidectomy. Incidence of ED was the primary outcome of the study. Data synthesis was performed by using Review Manager 5.4 software.

RESULTS

Twenty-three relevant studies involving a total of 1,996 children were identified. Perioperative use of esketamine reduced the incidence of ED in children undergoing tonsillectomy and adenoidectomy (RR = 0.33, 95% CI: [0.25, 0.44], p < 0.00001, I 2 = 0%). Scores of ED were lower in the esketamine group than in the control group (SMD = -1.20, 95% CI: [-1.56,-0.84], p < 0.00001, I 2 = 88%). Children in the esketamine group have lower postoperative pain scores (SMD = -0.51, 95% CI: [-0.80,-0.39], p < 0.00001, I 2 = 74%). Esketamine was also associated with a lower incidence of adverse events (RR = 0.75, 95% CI: [0.57, 0.99], p = 0.04, I 2 = 62%). We also found that the use of esketamine reduced the length of stay in the post-anesthetic care unit (PACU) but had no effect on the time to extubation.

CONCLUSION

Perioperative use of esketamine could significantly reduce the incidence of ED in children undergoing tonsillectomy and adenoidectomy. However, the optimal dose and timing of esketamine administration for preventing ED remains to be explored.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=558560, PROSPERO: CRD42024558560.

Effect of esketamine combined with dexmedetomidine on delirium in sedation for mechanically ventilated ICU patients: protocol for a nested substudy within a randomized controlled trial

BACKGROUND

Use of sedatives and analgesics is associated with the occurrence of delirium in critically ill patients receiving mechanical ventilation. Dexmedetomidine reduces the occurrence of delirium but may cause hypotension, bradycardia, and insufficient sedation. This substudy aims to determine whether the combination of esketamine with dexmedetomidine can reduce the side effects and risk of delirium than dexmedetomidine alone in mechanically ventilated patients.

METHODS

This single-center, randomized, active-controlled, superiority trial will be conducted at The First Affiliated Hospital of Nanjing Medical University. A total of 134 mechanically ventilated patients will be recruited and randomized to receive either dexmedetomidine alone or esketamine combined with dexmedetomidine, until extubation or for a maximum of 14 days. The primary outcome is the occurrence of delirium, while the second outcomes include the number of delirium-free days; subtype, severity, and duration of delirium; time to first onset of delirium; total dose of vasopressors and antipsychotics; duration of mechanical ventilation; ICU and hospital length of stay (LOS); accidental extubation, re-intubation, re-admission; and mortality in the ICU at 14 and 28 days.

DISCUSSION

There is an urgent need for a new combination regimen of dexmedetomidine due to its evident side effects. The combination of esketamine and dexmedetomidine has been applied throughout the perioperative period. However, there is still a lack of evidence on the effects of this regimen on delirium in mechanically ventilated ICU patients. This substudy will evaluate the effects of the combination of esketamine and dexmedetomidine in reducing the risk of delirium for mechanically ventilated patients in ICU, thus providing evidence of this combination to improve the short-term prognosis. The study protocol has obtained approval from the Medical Ethics Committee (ID: 2022-SR-450).

TRIAL REGISTRATION

ClinicalTrials.gov: NCT05466708, registered on 20 July 2022.

The influence of low-dose s-ketamine on postoperative delirium and cognitive function in older adults undergoing thoracic surgery

BACKGROUND

Postoperative delirium (POD) and cognitive dysfunction (POCD) are common complications following thoracic surgery, particularly in patients aged 65 years and above. These complications can significantly affect recovery and increase healthcare costs. This study investigates the effects of low-dose S-ketamine on reducing POD and POCD in this patient demographic.

METHODS

In this retrospective cohort study, medical records of patients aged ≥ 65 years who underwent elective thoracic surgery from January 2019 to August 2023 were reviewed. Patients were categorized into S-ketamine and Control groups based on intraoperative S-ketamine exposure. POD was assessed using the Confusion Assessment Method (CAM), while cognitive function was evaluated using the Montreal Cognitive Assessment (MoCA) at baseline, 1 week, 1 month, and 6 months post-surgery. Intraoperative and postoperative parameters, including hemodynamic stability, blood loss, pain scores, and ICU stay length, were also recorded.

RESULTS

The study comprised 140 participants, with 70 in each group. The S-ketamine group demonstrated a significantly lower incidence of POD at 7 days post-surgery (12.0% vs. 26.7%, P < 0.001), and reduced POCD at 1 month (18.7% vs. 36.0%, P < 0.05) and 6 months (10.7% vs. 21.3%, P < 0.05). The Ketamine group had a significantly higher median MoCA score compared to the Control group both at 1 month (P = 0.021) and 6 months (P = 0.007). Adverse events, such as infection, bleeding, and respiratory failure, showed no significant differences between the groups, suggesting a safe profile for S-ketamine.

CONCLUSION

Administering low-dose S-ketamine during thoracic surgery in patients aged 65 years and above significantly reduces the incidence of POD and POCD, highlighting its neuroprotective potential. These findings advocate for the inclusion of S-ketamine in anesthetic protocols to improve postoperative outcomes and reduce healthcare costs in this patient population.

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.

Recent advances in the study of anesthesia-and analgesia-related mechanisms of S-ketamine

Ketamine is a racemic mixture of equal amounts of R-ketamine and S-ketamine and is well known to anesthesiologists for its unique dissociative anesthetic properties. The pharmacological properties of ketamine, namely, its sympathetic excitation, mild respiratory depression, and potent analgesia, are still highly valued in its use as an anesthetic for some patients. In particular, since its advent, S-ketamine has been widely used as an anesthetic in many countries due to its increased affinity for NMDA receptors and its enhanced anesthetic and analgesic effects. However, the anesthetic and analgesic mechanisms of S-ketamine are not fully understood. In addition to antagonizing NMDA receptors, a variety of other receptors or channels may be involved, but there are no relevant mechanistic summaries in the literature. Therefore, the purpose of this paper is to review the mechanisms of action of S-ketamine on relevant receptors and systems in the body that result in its pharmacological properties, such as anesthesia and analgesia, with the aim of providing a reference for its clinical applications and research.