Effect of Dexmedetomidine on Postoperative Sleep Quality: A Systematic Review

Pharmacologic Sleep Aids in the Intensive Care Unit: A Systematic Review

Background: Patients in the intensive care unit (ICU) often experience poor sleep quality. Pharmacologic sleep aids are frequently used as primary or adjunctive therapy to improve sleep, although their benefits in the ICU remain uncertain. This review aims to provide a comprehensive assessment of the objective and subjective effects of medications used for sleep in the ICU, as well as their adverse effects. Methods: PubMed, Web of Science, Scopus, Embase, and Cochrane Central Register of Controlled Trials were systematically searched from their inception until June 2023 for comparative studies assessing the effects of pharmacologic sleep aids on objective and subjective metrics of sleep. Results: Thirty-four studies with 3498 participants were included. Medications evaluated were melatonin, ramelteon, suvorexant, propofol, and dexmedetomidine. The majority of studies were randomized controlled trials. Melatonin and dexmedetomidine were the best studied agents. Objective sleep metrics included polysomnography (PSG), electroencephalography (EEG), bispectral index, and actigraphy. Subjective outcome measures included patient questionnaires and nursing observations. Evidence for melatonin as a sleep aid in the ICU was mixed but largely not supportive for improving sleep. Evidence for ramelteon, suvorexant, and propofol was too limited to offer definitive recommendations. Both objective and subjective data supported dexmedetomidine as an effective sleep aid in the ICU, with PSG/EEG in 303 ICU patients demonstrating increased sleep duration and efficiency, decreased arousal index, decreased percentage of stage N1 sleep, and increased absolute and percentage of stage N2 sleep. Mild bradycardia and hypotension were reported as side effects of dexmedetomidine, whereas the other medications were reported to be safe. Several ongoing studies have not yet been published, mostly on melatonin and dexmedetomidine. Conclusions: While definitive conclusions cannot be made for most medications, dexmedetomidine improved sleep quantity and quality in the ICU. These benefits need to be balanced with possible hemodynamic side effects.

The influence of sleep disorders on perioperative neurocognitive disorders among the elderly: A narrative review

This review comprehensively assesses the epidemiology, interaction, and impact on patient outcomes of perioperative sleep disorders (SD) and perioperative neurocognitive disorders (PND) in the elderly. The incidence of SD and PND during the perioperative period in older adults is alarmingly high, with SD significantly contributing to the occurrence of postoperative delirium. However, the clinical evidence linking SD to PND remains insufficient, despite substantial preclinical data. Therefore, this study focuses on the underlying mechanisms between SD and PND, underscoring that potential mechanisms driving SD-induced PND include uncontrolled central nervous inflammation, blood-brain barrier disruption, circadian rhythm disturbances, glial cell dysfunction, neuronal and synaptic abnormalities, impaired central metabolic waste clearance, gut microbiome dysbiosis, hippocampal oxidative stress, and altered brain network connectivity. Additionally, the review also evaluates the effectiveness of various sleep interventions, both pharmacological and nonpharmacological, in mitigating PND. Strategies such as earplugs, eye masks, restoring circadian rhythms, physical exercise, noninvasive brain stimulation, dexmedetomidine, and melatonin receptor agonists have shown efficacy in reducing PND incidence. The impact of other sleep-improvement drugs (e.g., orexin receptor antagonists) and methods (e.g., cognitive-behavioral therapy for insomnia) on PND is still unclear. However, certain drugs used for treating SD (e.g., antidepressants and first-generation antihistamines) may potentially aggravate PND. By providing valuable insights and references, this review aimed to enhance the understanding and management of PND in older adults based on SD.

Efficacy of epidural esketamine on postoperative sleep quality after laparoscopic and robotic lower abdominal surgeries: a study protocol for randomised, double-blind, controlled trial

INTRODUCTION

Postoperative sleep disturbances significantly impair postoperative recovery. The administration of intravenous esketamine has been shown to potentially improve postoperative sleep quality. However, the effectiveness of epidural esketamine in improving postoperative sleep quality remains to be elucidated. This study aims to explore the impact of both intraoperative and postoperative use of epidural esketamine on the postoperative sleep quality of patients undergoing minimally invasive lower abdominal surgeries.

METHODS AND ANALYSIS

This randomised, double-blind, parallel-group, placebo-controlled trial will be conducted at the Fudan University Shanghai Cancer Centre. A total of 128 adults undergoing minimally invasive lower abdominal surgeries will be randomly allocated in a 1:1 ratio to either the esketamine group or the placebo group. In the esketamine group, epidural esketamine will be administered intraoperatively (0.2 mg/kg) and postoperatively (25 mg). Postoperatively, all patients will receive epidural analgesia. The primary outcome of the study is the incidence of poor sleep quality on the third day after surgery. The sleep quality assessment will be conducted using the Pittsburgh Sleep Quality Index and a Numeric Rating Scale of sleep. The main secondary outcomes include postoperative pain and anxiety and depression scores. The postoperative pain, both rest pain and movement pain, will be assessed using a Numerical Rating Scale within 5 days after surgery. Anxiety and depression scores will be evaluated using the Hospital Anxiety and Depression Scale both before and after the surgery. Safety outcomes will include delirium, fidgeting, hallucinations, dizziness and nightmares. The analyses will be performed in accordance with intention-to-treat principle ETHICS AND DISSEMINATION: Ethics approval has been obtained from the Ethics Committee of the Shanghai Cancer Centre (2309281-9). Prior to participation, all patients will provide written informed consent. The results of the trial are intended to be published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

ChiCTR2300076862.

Safety and effcacy of remimazolam tosilate for sedation during combined spinal-epidural anesthesia for orthopedic procedures: a randomized controlled trial

OBJECTIVE

The objective of this study was to assess the efficacy and safety of Remimazolam in the context of combined spinal-epidural anesthesia for sedation during orthopedic surgery.

METHODS

This randomized controlled trial enrolled patients scheduled for orthopedic surgery under combined spinal-epidural anesthesia (N = 80), who were randomly allocated to receive either dexmedetomidine (Group-D) or remimazolam (Group-R). The target sedation range aimed for a Ramsay score of 2-5 or a BIS value of 60-80 to evaluate the effectiveness and safety of remimazolam during sedation.

RESULTS

The time taken to achieve the desired level of sedation was significantly shorter in the remimazolam group compared to the dexmedetomidine group (3.69 ± 0.75 vs. 9.59 ± 1.03; P < 0.0001). Patients in the remimazolam group exhibited quicker recovery, fewer intraoperative adverse events, more consistent vital signs, and greater satisfaction at various time points throughout the surgery.

CONCLUSION

This preliminary study demonstrates that remimazolam tosilate serves as a safe and effective sedative for orthopedic surgery performed under combined spinal-epidural anesthesia, in comparison with dexmedetomidine.

Effect of Dexmedetomidine on Postpartum Depression in Women With Prenatal Depression: A Randomized Clinical Trial

Importance

Postpartum depression (PPD) is emerging as a major public health problem worldwide. Although the particular period and context in which PPD occurs provides an opportunity for preventive interventions, there is still a lack of pharmacologic prevention strategies for PPD.

Objective

To assess the efficacy and safety of dexmedetomidine for prevention of PPD among women with prenatal depression undergoing cesarean delivery.

Design, Setting, and Participants

This randomized clinical trial enrolled 338 women who screened positive for prenatal depression at 2 hospitals in Hunan, China from March 28, 2022, to April 16, 2023. Women with an Edinburgh Postnatal Depression Scale score of more than 9 who were 18 years of age or older and were scheduled for elective cesarean delivery were eligible.

Interventions

Eligible participants were randomly assigned in a 1:1 ratio to either the dexmedetomidine group or the control group via centrally computer-generated group randomization. Dexmedetomidine, 0.5 μg/kg and 0.9% saline were intravenously infused for 10 minutes after delivery in the dexmedetomidine and control groups, respectively. After infusion, sufentanil or dexmedetomidine plus sufentanil was administered via patient-controlled intravenous analgesia for 48 hours in the control group and dexmedetomidine group, respectively.

Main Outcomes and Measures

The primary outcome was positive PPD screening results at 7 and 42 days post partum, defined as a postpartum Edinburgh Postnatal Depression Scale score of more than 9. Analysis was on an intention-to-treat basis.

Results

All 338 participants were female, with a mean (SD) age of 31.5 (4.1) years. Positive PPD screening incidence at 7 and 42 days post partum in the dexmedetomidine group vs the control group was significantly decreased (day 7, 21 of 167 [12.6%] vs 53 of 165 [32.1%]; risk ratio, 0.39 [95% CI, 0.25-0.62]; P < .001; day 42, 19 of 167 [11.4%] vs 50 of 165 [30.3%]; risk ratio, 0.38 [95% CI, 0.23-0.61]; P < .001). The dexmedetomidine group showed no significant difference in adverse events vs the control group (46 of 169 [27.2%] vs 33 of 169 [19.5%]; P = .10), but the incidence of hypotension increased (31 of 169 [18.3%] vs 16 of 169 [9.5%]; risk ratio, 2.15 [95% CI, 1.13-4.10]; P = .02).

Conclusions and Relevance

Dexmedetomidine administration in the early postpartum period significantly reduced the incidence of a positive PPD screening and maintained a favorable safety profile.

Trial Registration

Chinese Clinical Trial Registry Identifier: ChiCTR2200057213.

Dexmedetomidine, an alpha 2A receptor agonist, triggers seizures unilaterally in GAERS during the pre-epileptic phase: does the onset of spike-and-wave discharges occur in a focal manner?

Introduction

The genetic absence epilepsy rat from Strasbourg (GAERS) is a rat model for infantile absence epilepsy with spike-and-wave discharges (SWDs). This study aimed to investigate the potential of alpha 2A agonism to induce seizures during the pre-epileptic period in GAERS rats.

Methods

Stereotaxic surgery was performed on male pups and adult GAERS rats to implant recording electrodes in the frontoparietal cortices (right/left) under anesthesia (PN23-26). Following the recovery period, pup GAERS rats were subjected to electroencephalography (EEG) recordings for 2 h. Before the injections, pup epileptiform activity was examined using baseline EEG data. Dexmedetomidine was acutely administered at 0.6 mg/kg to pup GAERS rats 2-3 days after the surgery and once during the post-natal (PN) days 25-29. Epileptiform activities before injections triggered unilateral SWDs and induced sleep durations, and power spectral density was evaluated based on EEG traces.

Results

The most prominent finding of this study is that unilateral SWD-like activities were induced in 47% of the animals with the intraperitoneal dexmedetomidine injection. The baseline EEGs of pup GAERS rats had no SWDs as expected since they are in the pre-epileptic period but showed low-amplitude non-rhythmic epileptiform activity. There was no difference in the duration of epileptiform activities between the basal EEG groups and DEX-injected unilateral SWD-like-exhibiting and non-SWD-like activities groups; however, the sleep duration of the unilateral SWD-like-exhibiting group was shorter. Power spectrum density (PSD) results revealed that the 1.75-Hz power in the left hemisphere peaks significantly higher than in the right.

Discussion

As anticipated, pup GAERS rats in the pre-epileptic stage showed no SWDs. Nevertheless, they exhibited sporadic epileptiform activities. Specifically, dexmedetomidine induced SWD-like activities solely within the left hemisphere. These observations imply that absence seizures might originate unilaterally in the left cortex due to α2AAR agonism. Additional research is necessary to explore the precise cortical focal point of this activity.

Intranasal dexmedetomidine improves postoperative sleep quality in older patients with chronic insomnia: a randomized double-blind controlled trial

Objective: This study was determined to investigate the impact of intranasal dexmedetomidine (DEX) on postoperative sleep quality in older patients (age over 65) with chronic insomnia during their hospitalization after surgery. Design: A randomized double-blind controlled trial was conducted to compare the effects of intranasal dexmedetomidine spray with a placebo group. Setting and Participants: The study was carried out at Xiangya Hospital, Central South University. 110 participants with chronic insomnia were analyzed. Methods: This trial enrolled older patients who underwent total hip/knee arthroplasty and randomized them to receive intranasal dexmedetomidine (2.0 μg/kg) or saline daily at around 9 p.m. after surgery until discharge. The primary outcomes were subjective sleep quality assessed with the Leeds Sleep Evaluation Questionnaire (LSEQ). The secondary outcomes included the objective sleep quality measured with the Acti-graph, the Pittsburgh Sleep Quality Index (PSQI), the Insomnia Severity Index (ISI). The other outcomes included the incidence of delirium, levels of inflammatory factors, visual analog scale (VAS) pain scores, postoperative opioid consumption, and treatment-related adverse events. Results: 174 patients were screened for eligibility, and 110 were recruited and analyzed. The DEX group had significantly higher scores on both the LSEQ-Getting to sleep and LSEQ-Quality of Sleep at each time point compared to the placebo (p < 0.0001), The least squares (LS) mean difference in LSEQ-GTS score at T0 between placebo group and DEX group was 2 (95% CI, -1-6), p = 0.4071 and at T5 was -14 (95% CI, -17 to -10), p < 0.0001; The LS mean difference in the LSEQ-QOS score at T0 was -1 (95% CI, -4 to 1), p = 0.4821 and at T5 was -16 (95% CI, -21 to -10), p < 0.0001. The DEX group exhibited significant improvement in Total Sleep Time (TST), Sleep Onset Latency (SOL), and Sleep Efficiency (SE), at each time point after treatment compared to the placebo group (p < 0.0001). The PSQI and ISI scores in the DEX group were reduced after treatment (p < 0.001). No significant adverse events were reported with the use of dexmedetomidine. Conclusion and Implications: This study demonstrates that intranasal administration of dexmedetomidine improves postoperative sleep quality in older patients with chronic insomnia who undergo surgery, without increasing the incidence of adverse effects. Clinical Trial Registration: http://www.chictr.org.cn/, identifier ChiCTR2200057133.

Application of the Plan-Do-Study-Act method to optimize the ordering and administration of dexmedetomidine for sleep hygiene in the intensive care unit

PURPOSE

To describe the Plan-Do-Study-Act (PDSA) methodology utilized by a multidisciplinary team to address the discordance between ordering and administration of dexmedetomidine for sleep hygiene in the intensive care unit (ICU).

SUMMARY

The addition of sleep hygiene as an indication for the use of dexmedetomidine at University of Virginia (UVA) Health led to discordance between the medication orders in the electronic medical record and the subsequent administration of dexmedetomidine. A multidisciplinary team implemented interventions that included modifying the order panel, streamlining the institutional formulary, developing institutional practice guidelines, and providing education to healthcare team members. After completion of the first PDSA cycle, the mean number of discordant order elements decreased to 1.96 out of 5 possible order elements from an initial 2.5 out of 5 elements before the interventions, meeting the aim to reduce the mean to less than 2. There was a significant decrease in the discordance in the duration of infusion (discordant for 14 of 30 orders before the interventions vs 1 of 28 orders after the interventions, P = 0.0002) but a significant increase in the discordance in the titration dose (discordant for 13 of 30 orders before the interventions vs 24 of 28 orders after the interventions, P < 0.0001). Other discordant order elements including the starting dose, maximum rate, and titration interval time decreased in frequency after the interventions, although the differences were not statistically significant. The interventions made during the first PDSA cycle are anticipated to lead to an estimated cost savings of up to $180,000 per year within the UVA Health system.

CONCLUSION

The multidisciplinary team utilizing a PDSA method to modify the order panel, streamline the institutional formulary, develop institutional practice guidelines, and provide education to healthcare team members was effective at reducing overall discordance between order intent and administration of dexmedetomidine for sleep hygiene in the ICU.

Development and validation of a nomogram for postoperative sleep disturbance in adults: a prospective survey of 640 patients undergoing spinal surgery

BACKGROUND

Postoperative sleep disturbance (PSD) is a prevalent clinical complication that may arise due to various factors. The purpose of this investigation is to identify the risk factors for PSD in spinal surgery and establish a risk prediction nomogram.

METHODS

The clinical records of individuals who underwent spinal surgery from January 2020 to January 2021 were gathered prospectively. The least absolute shrinkage and selection operator (LASSO) regression, along with multivariate logistic regression analysis, was employed to establish independent risk factors. A nomogram prediction model was devised based on these factors. The nomogram's effectiveness was evaluated and verified via the receiver operating characteristic (ROC) curve, calibration plot, and decision curve analysis (DCA).

RESULTS

A total of 640 patients who underwent spinal surgery were analyzed in this investigation, among which 393 patients experienced PSD with an incidence rate of 61.4%. After conducting LASSO regression and logistic regression analyses using R software on the variables in training set, 8 independent risk factors associated to PSD were identified, including female, preoperative sleep disorder, high preoperative anxiety score, high intraoperative bleeding volume, high postoperative pain score, dissatisfaction with ward sleep environment, non-use of dexmedetomidine and non-use of erector spinae plane block (ESPB). The nomogram and online dynamic nomogram were constructed after incorporating these variables. In the training and validation sets, the area under the curve (AUC) in the receiver operating characteristic (ROC) curves were 0.806 (0.768-0.844) and 0.755 (0.667-0.844), respectively. The calibration plots indicated that the mean absolute error (MAE) values in both sets were respectively 1.2% and 1.7%. The decision curve analysis demonstrated the model had a substantial net benefit within the range of threshold probabilities between 20% and 90%.

CONCLUSIONS

The nomogram model proposed in this study included eight frequently observed clinical factors and exhibited favorable accuracy and calibration.

TRIAL REGISTRATION

The study was retrospectively registered with the Chinese Clinical Trial Registry (ChiCTR2200061257, 18/06/2022).

The prevalence and risk factors of sleep disturbances in surgical patients: A systematic review and meta-analysis

Determining the prevalence and risk factors related to sleep disturbance in surgical patients would be beneficial for risk stratification and perioperative care planning. The objectives of this systematic review and meta-analysis are to determine the prevalence and risk factors of sleep disturbances and their associated postoperative complications in surgical patients. The inclusion criteria were: (1) patients ≥18 years old undergoing a surgical procedure, (2) in-patient population, and (3) report of sleep disturbances using a validated sleep assessment tool. The systematic search resulted in 21,951 articles. Twelve patient cohorts involving 1497 patients were included. The pooled prevalence of sleep disturbances at preoperative assessment was 60% (95% Confidence Interval (CI): 50%, 69%) and the risk factors for postoperative sleep disturbances were a high preoperative Pittsburgh sleep quality index (PSQI) score indicating preexisting disturbed sleep and anxiety. Notably, patients with postoperative delirium had a higher prevalence of pre- and postoperative sleep disturbances and high preoperative wake after sleep onset percentage (WASO%). The high prevalence of preoperative sleep disturbances in surgical patients has a negative impact on postoperative outcomes and well-being. Further work in this area is warranted.

Effect of intraoperative remimazolam on postoperative sleep quality in elderly patients after total joint arthroplasty: a randomized control trial

PURPOSE

To investigate the effect of intraoperative remimazolam sedation on postoperative sleep quality in elderly patients after total joint arthroplasty.

METHODS

Between May 15, 2021 and March 26, 2022, 108 elderly patients (age ≥ 65 years) who received total joint arthroplasty under neuraxial anesthesia were randomized into remimazolam group (a loading dose of 0.025-0.1 mg/kg and followed by an infusion rate of 0.1-1.0 mg/kg/h till end of surgery) or routine group (sedation was given on patient's requirement by dexmedetomidine 0.2-0.7 μg/kg/h). Primary outcome was the subjective sleep quality at surgery night which was evaluated by Richards Campbell Sleep Questionnaire (RCSQ). Secondary outcomes included RCSQ scores at postoperative first and second nights and numeric rating scale pain intensity within first 3 days after surgery.

RESULTS

RCSQ score at surgery night was 59 (28, 75) in remimazolam group which was comparable with 53 (28, 67) in routine group (median difference 6, 95% CI - 6 to 16, P = 0.315). After adjustment of confounders, preoperative high Pittsburg sleep quality index was associated worse RCSQ score (P = 0.032), but not remimazolam (P = 0.754). RCSQ score at postoperative first night [69 (56, 85) vs. 70 (54, 80), P = 0.472] and second night [80 (68, 87) vs. 76 (64, 84), P = 0.066] were equivalent between two groups. Safety outcomes were comparable between the two groups.

CONCLUSIONS

Intraoperative remimazolam did not significantly improve postoperative sleep quality in elderly patients undergoing total joint arthroplasty. But it is proved to be effective and safe for moderate sedation in these patients.

CLINICAL TRIAL NUMBER AND REGISTRY URL

ChiCTR2000041286 ( www.chictr.org.cn ).

Intraoperative dexmedetomidine on postoperative pain in gastrointestinal surgery: an observational study

BACKGROUND

Dexmedetomidine (DEX) is widely used for adjuvant sedation and analgesia in gastrointestinal surgeries. The authors aimed to reassess the effects of intraoperative DEX on acute pain by comprehensive analysis of the multiple dimensions of pain.

MATERIALS AND METHODS

In this multicentre cohort study, patients undergoing gastrointestinal surgeries were prospectively enrolled in the China Acute Postoperative Pain Study. Patients were divided into DEX and non-DEX groups based on whether DEX was used during surgery. Patient satisfaction with pain treatment (rated on a numeric rating score, 0-10) and other pain-related outcomes were evaluated using the International Pain Outcome Questionnaire on the first postoperative day. The effects of intraoperative DEX were analyzed using logistic or linear regression for dichotomous or continuous variables, respectively. Propensity score matching and subgroup analyses were performed to appraise the correlation between intraoperative DEX and postoperative pain outcomes.

RESULTS

Of the 1260 patients eligible for analysis, 711 (56.4%) received intraoperative DEX. Propensity score matching resulted in 415 patients in each group. Intraoperative DEX was associated with higher patient satisfaction (β: 0.556; 95% CI: 0.366-0.745), and a decrease in the percentage of time spent in severe pain (β: -0.081; 95% CI: -0.104- -0.058), anxiety (odds ratio: 0.394; 95% CI: 0.307-0.506), helplessness (odds ratio: 0.539; 95% CI: 0.411-0.707), and postoperative opioid consumption (β: -16.342; 95% CI: -27.528- -5.155).

CONCLUSIONS

Intraoperative DEX was associated with the prognosis of acute postoperative pain in multiple aspects in patients undergoing major gastrointestinal surgery, including increased patient satisfaction, and a reduction in the duration of severe pain, postoperative anxiety and helplessness, and postoperative opioid consumption. Future studies to determine the dose and timing of DEX administration on pain-related outcomes are warranted.

[Ultrasound-guided stellate ganglion block improves sleep quality in elderly patients early after thoracoscopic surgery for lung cancer: a randomized controlled study]

OBJECTIVE

To investigate the effects of ultrasound-guided stellate ganglion block (SGB) on sleep quality in elderly patients with lung cancer early after thoracoscopic surgery.

METHODS

A total of 86 patients with lung cancer (ASA class I-III, aged 60-80 years) undergoing elective thoracoscopic surgery were randomized into stellate ganglion block (SGB) group (n=43) and control group (n=43) to receive ultrasound-guided right SGB with 7 mL of 0.5% ropivacaine at the C6-7 level and injection of 7 mL saline at the same site 30 min before anesthesia induction, respectively. On the day before surgery and the first two days after the surgery, sleep duration, sleep efficiency index (SEI) and N3 sleep stage of the patients were monitored using a BIS-Vista monitor, and Athens Insomnia Scale (AIS) scores were recorded. The plasma levels of norepinephrine and cortisol of the patients were measured before SGB (T1), at 5 min after extubation (T2) and at 6:00 on the first morning after the surgery (T4). Urine levels of 6-hydroxysulfate melatonin (6-HMS) were measured at 6:00 in the morning for 3 consecutive days starting on the day of surgery (T3, T4 and T5, respectively). VAS score, incidences of postoperative delirium and depression, sufentanil consumption after surgery, and discharge time of the patients were recorded.

RESULTS

Thirty-six patients in SGB group and 35 in the control group were analyzed. In both groups, most of the patients had insomnia after surgery, but compared with those in the control group, the patients in SGB group had significantly longer sleep duration (P < 0.05) with a higher sleep efficiency index (P < 0.05) and a longer sleep time in N3 stage (P < 0.05) on the first two nights after surgery. The mean postoperative AIS score and incidence of insomnia were significantly lower in SGB group than in the control group (P < 0.05). Compared with the control group, SGB group showed significantly lower plasma levels of norepinephrine and cortisol at T2 and T4 (P < 0.05), a higher urine level of 6-HMS at T5 (P < 0.05), and a shorter discharge time after the surgery (P < 0.05). The VAS scores, postoperative incidences of delirium and depression, or postoperative sufentanil consumption did not differ significantly between the two groups.

CONCLUSION

Ultrasound-guided SGB improves objective and subjective sleep quality in elderly patients early after thoracoscopic surgery for lung cancer to alleviate stress responses and sleep disorders, reduce postoperative hospital stay, and accelerate postoperative recovery of the patients.

Could dexmedetomidine be repurposed as a glymphatic enhancer?

Cerebrospinal fluid (CSF) flows through the central nervous system (CNS) via the glymphatic pathway to clear the interstitium of metabolic waste. In preclinical studies, glymphatic fluid flow rate increases with low central noradrenergic tone and slow-wave activity during natural sleep and general anesthesia. By contrast, sleep deprivation reduces glymphatic clearance and leads to intracerebral accumulation of metabolic waste, suggesting an underlying mechanism linking sleep disturbances with neurodegenerative diseases. The selective α₂-adrenergic agonist dexmedetomidine is a sedative drug that induces slow waves in the electroencephalogram, suppresses central noradrenergic tone, and preserves glymphatic outflow. As recently developed dexmedetomidine formulations enable self-administration, we suggest that dexmedetomidine could serve as a sedative-hypnotic drug to enhance clearance of harmful waste from the brain of those vulnerable to neurodegeneration.

Effect of Perioperative Dexmedetomidine Infusion on Postoperative Delirium in Elderly Patients Undergoing Oral and Maxillofacial Surgery: A Randomized Controlled Clinical Trial

Purpose

The aim of the study was to determine whether perioperative dexmedetomidine administration can improve postoperative delirium in elderly patients undergoing oral and maxillofacial surgery.

Patients and Methods

This was a prospective double-blind randomized controlled clinical trial conducted in Cangzhou Central Hospital from December 2021 to March 2022. Patients aged 65 and older underwent oral and maxillofacial surgery under general anesthesia. Eligible patients were randomly assigned to dexmedetomidine or control group. Dexmedetomidine was injected intravenously from 10 min before induction of anesthesia to 30 min before the end of surgery in dexmedetomidine group, while patients in the control group were given normal saline at the same rate during the same time period. The primary measurement indicators were the incidence and duration of delirium in the first five days after surgery. The secondary measurement indicators were Visual Analogue Score (VAS) for the first 24 hours following surgery, subjective sleep quality score within 24 hours postoperatively and intraoperative adverse reactions.

Results

One hundred and twenty patients were randomly assigned. Baseline characteristics were similar between two groups. The incidence and duration of postoperative delirium did not differ statistically between two groups (all P > 0.05). Compared with control group, VAS scores in dexmedetomidine group were significantly lower at 6, 12, and 24 hours after surgery (all P < 0.05); moreover, Richards-Campbell Sleep Questionnaire (RCSQ) results were significantly improved 1 day after surgery in dexmedetomidine group (P < 0.05). Dexmedetomidine-related adverse reactions were similar in both groups (P > 0.05).

Conclusion

Intravenous infusion of dexmedetomidine 10 min before induction of anesthesia to half an hour before the end of surgery did not improve postoperative delirium in elderly patients undergoing oral and maxillofacial surgery; however, dexmedetomidine may be associated with decreased postoperative pain and improved postoperative sleep quality.

Analgesic and Sedative Effects of Different Doses of Dexmedetomidine Combined with Butorphanol in Continuous Analgesia after a Cesarean Section

Objective

The present study is designed to study the analgesic and sedative effect of different doses of dexmedetomidine combined with butorphanol in continuous analgesia after a cesarean section.

Methods

A total of 60 puerperae undergoing a cesarean section recruited from a single center were divided into three groups according to the postoperative continuous analgesia protocol: control group (100 mL of normal saline containing 10 µg/kg fentanyl and 0.25 mg of palonosetron, 2 mL/h for continuous analgesia for 48 h), DB1 group (100 mL of normal saline containing 1.0 µg/kg dexmedetomidine, 4 mg of butorphanol, 10 µg/kg fentanyl, and 0.25 mg of palonosetron, 2 mL/h for continuous analgesia for 48 h), and DB2 group (100 mL normal saline containing 2.0 µg/kg dexmedetomidine, 4 mg of butorphanol, 10 µg/kg fentanyl, and 0.25 mg of palonosetron, 2 mL/h for continuous analgesia for 48 h). We compared the blood pressure, heart rate, oxygen saturation, VAS score, Ramsay score, and adverse reactions of puerperae among the three groups after surgery.

Results

The baseline data all have no significant difference in the three groups (p > 0.05). Compared with those in the control group, the systolic blood pressure, diastolic blood pressure, heart rate, and VAS score of the puerperae in the DB1 group and DB2 group were significantly decreased at 6, 24, and 48 h (P < 0.05), while the Ramsay scores of the puerperae in DB1 group and DB2 group were significantly increased at 6, 24, and 48 h (p < 0.05). At the same time, the systolic blood pressure, diastolic blood pressure, heart rate, and VAS score of the puerperae in the DB2 group were significantly lower than those in the DB1 group (P < 0.05), while the Ramsay scores of the puerperae in DB2 group were significantly higher than those in the DB1 group (P < 0.05). Also, there is no significant difference in oxygen saturation and adverse reactions of puerperae among the three groups after surgery (p > 0.05).

Conclusion

Dexmedetomidine combined with butorphanol can improve the analgesic and sedative effects in continuous analgesia after a cesarean section, and the analgesic and sedative effects of dexmedetomidine in the high-dose group are better than those in the low-dose group.

Recent Advances in the Clinical Value and Potential of Dexmedetomidine

Dexmedetomidine, a highly selective α2-adrenoceptor agonist, has sedative, anxiolytic, analgesic, sympatholytic, and opioid-sparing properties and induces a unique sedative response which shows an easy transition from sleep to wakefulness, thus allowing a patient to be cooperative and communicative when stimulated. Recent studies indicate several emerging clinical applications via different routes. We review recent data on dexmedetomidine studies, particularly exploring the varying routes of administration, experimental implications, clinical effects, and comparative advantages over other drugs. A search was conducted on the PubMed and Web of Science libraries for recent studies using different combinations of the words “dexmedetomidine”, “route of administration”, and pharmacological effect. The current routes, pharmacological effects, and application categories of dexmedetomidine are presented. It functions by stimulating pre- and post-synaptic α2-adrenoreceptors within the central nervous system, leading to hyperpolarization of noradrenergic neurons, induction of an inhibitory feedback loop, and reduction of norepinephrine secretion, causing a sympatholytic effect, in addition to its anti-inflammation, sleep induction, bowel recovery, and sore throat reduction effects. Compared with similar α2-adrenoceptor agonists, dexmedetomidine has both pharmacodynamics advantage of a significantly greater α2:α1-adrenoceptor affinity ratio and a pharmacokinetic advantage of having a significantly shorter elimination half-life. In its clinical application, dexmedetomidine has been reported to present a significant number of benefits including safe sedation for various surgical interventions, improvement of intraoperative and postoperative analgesia, sedation for compromised airways without respiratory depression, nephroprotection and stability of hypotensive hemodynamics, reduction of postoperative nausea and vomiting and postoperative shivering incidence, and decrease of intraoperative blood loss. Although the clinical application of dexmedetomidine is promising, it is still limited and further research is required to enhance understanding of its pharmacological properties, patient selection, dosage, and adverse effects.

Median Effective Dose of Dexmedetomidine Inducing Bradycardia in Elderly Patients Determined by Up-and-Down Sequential Allocation Method

Purpose: When dexmedetomidine is used in elderly patients, high incidence of bradycardia is reported. Given age-related physiological changes in this population, it is necessary to know the safety margin between the loading dose of dexmedetomidine and bradycardia. Therefore, we conducted this study to investigate the median effective dose (ED50) of dexmedetomidine causing bradycardia in elderly patients. Methods: Thirty patients with ages over 65 years undergoing elective general surgery were enrolled. The Dixon and Massay sequential method were applied to determine the loading dose of dexmedetomidine, starting from 1.0 µg/kg. The dose for the follow-up subjects increased or decreased according to the geometric sequence with the common ratio 1.2, based on the 'negative' or 'positive' response of the previous subject. Positive mean that the subject developed bradycardia during the test. Hemodynamic data including heart rate and systolic blood pressure were recorded. The level of sedation was assessed with the Observer Assessment of Alertness and Sedation Scale (OAA/S). Results: Bradycardia occurred in 13 patients (43.3%). The ED50 of dexmedetomidine causing bradycardia was 1.97 µg/kg (95% CI, 1.53-2.53 µg/kg). OAA/S scores at 10 min after the beginning of the dexmedetomidine infusion and 10 min after the termination of dexmedetomidine administration showed no significant differences between the positive and negative groups (P > 0.05). Conclusion: The ED50 of dexmedetomidine causing bradycardia in our cohort was higher than clinical recommended dose. A higher loading dose appears acceptable for a faster onset of sedation under careful hemodynamic monitoring. Trial registration: ChiCTR 15006368.