An Updated Focused Review of Dexmedetomidine in Adults

Global Trends in Research Related to Emergence Agitation From 1978 to 2023: A Bibliometric Analysis

PURPOSE

Emergence agitation (EA) is a postoperative behavioral disorder characterized by a lack of connection between consciousness and behavior. Despite its clinical importance and prevalence in the postoperative setting, the research focus and knowledge structure remain to be systematically mapped. Therefore, we conducted a bibliometric analysis from 1978 to 2023 to address this gap. This study aims to excavate research hotspots, map knowledge structure, uncover emerging trends, and provide invaluable insights for guiding future research endeavors.

DESIGN

A bibliometric analysis of emergency agitation.

METHODS

We conducted a literature search in the Web of Science Core Collection for articles on EA published between 1978 and 2023. We collected data on countries, institutions, journals, authors, citations, and keywords. Subsequently, we comprehensively analyzed the gathered knowledge units using three tools, including VOSviewer, HistCite Pro, and ArcGIS Pro.

FINDINGS

From 1978 to 2023, we retrieved 948 pieces of literature on EA, with the number of publications increasing yearly. China ranked first in the number of publications (n = 253, 26.69%). The United States was the most cited and influential country, closely collaborating with other countries (5,661 citations, H-index 57, citations per publication 37.99, total link strength [TLS] 24). Yonsei University was the most productive and influential institution (n = 18, 1.9%, 427 citations, H-index 12, citations per publication 23.72). Shanghai Jiao Tong University had close collaborative relationships with other universities (TLS 7). The journal with the most publications and influence was Pediatric Anaesthesia (n = 46, 4.92%, H-index 32). Anaesthesia and Analgesia was the most cited journal (2,849 citations). M.T. Aouad was the most influential and productive author devoted to studying EA (n = 6, 0.63%, 173 citations, TLS 3,002). The most influential reference was "Greater incidence of delirium during recovery from sevoflurane anaesthesia in preschool boys" (author J. Aono, No. 19, IF = 8.8, Q1, local citation score 147). Hot research directions in EA include EA and emergence delirium, propofol and EA, risk factors of EA, EA in pediatric anaesthesia, dexmedetomidine, and EA induced by sevoflurane. Esketamine, nalbuphine, sugammadex, and dezocine are drugs that have received increased attention in recent years.

CONCLUSIONS

The study mapped the knowledge structure of EA and identified six prominent research directions, four drugs of significant research interest, and emerging thematic trends. These findings offer insights into the current state of research on EA, providing a comprehensive view of the field's landscape.

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.

Comparative Study of Levobupivacaine Versus Levobupivacaine With Dexmedetomidine as an Adjuvant in Transversus Abdominis Block for Postoperative Pain Relief in Abdominal Hysterectomy Patients: A Randomized, Double-Blind Study

Background Adjuvants have been discovered to prolong the analgesic impact of local anesthetics (LA), while the transversus abdominis plane (TAP) block offers sufficient postoperative pain relief after various abdominal procedures. Nevertheless, the impact of the given LA will determine the duration of the TAP block. Thus, in this investigation, we aimed to estimate the analgesic impact of combining dexmedetomidine (DEX) with levobupivacaine in the TAP block for patients having an infraumbilical incision for an abdominal hysterectomy while under spinal anesthetic. Aim This study aimed to determine the analgesic effect of DEX (0.5 mcg/kg) to 20 ml of 0.25% levobupivacaine on each side in the TAP block in patients undergoing total abdominal hysterectomy (TAH). Materials and methods Two groups of 30 patients each, with ASA grades 1 and 2, were randomly selected from patients. Group N, comprising 30 patients, had a bilateral TAP block using 2 mL of normal saline and 20 mL of 0.25% levobupivacaine. Group D (n = 30 patients) was given DEX at a dose of 0.5 mcg/kg (2 mL) in addition to 20 mL of 0.25% levobupivacaine given bilaterally. The TAP block was administered just after skin closure. Time of the initial analgesic dose administration; total fentanyl doses utilized as rescue analgesia; pain scores (numerical rating scale (NRS)) at 2, 4, 6, 8, 12, and 24 hours; and pre- and postoperative cortisol levels were also noted. For each group, 1 gram IV paracetamol was administered every eight hours. Drugs used for rescue analgesia (RA) were diclofenac 75 mg IV stat and fentanyl 1 mcg/kg. Results and discussion In addition to Group N having lower NRS scores at rest, Group D had a considerably longer time for initial rescue analgesia than Group N. There was also a significant decrease in the total fentanyl consumption and postoperative serum cortisol levels in Group D in contrast to Group N. Conclusion Potential adjuvant DEX prolongs postoperative analgesia in patients experiencing abdominal hysterectomy when used alongside LA in TAP.

Ventricular Tachycardia Following Ephedrine During Dexmedetomidine Dental Procedural Sedation

We present the case of a 46-year-old man who received ephedrine for hypotension after surgery for a mandibular lesion under intravenous (IV) moderate sedation with dexmedetomidine (DEX) and experienced transient ventricular tachycardia (VT). The patient was scheduled to have cystectomy and multiple apicoectomies for the mandibular periapical infection and the simple bone cyst. Other than obesity, snoring, and a nonalcoholic fatty liver, he denied any other significant medical history, medications, or allergies. The surgery was successful; however, his blood pressure dropped after stopping the DEX infusion. Ephedrine was administered IV several times, which resulted in the onset of VT on the electrocardiogram (ECG). His blood pressure could not be measured at the time, but he was able to respond and breathe independently. A defibrillator was immediately made available. The ECG revealed a spontaneous transition from VT to atrial fibrillation with ST depression. Because he was unable to revert to a normal sinus rhythm, the patient was transferred to a general hospital, where he underwent additional testing. No abnormalities were observed in his heart or brain. After DEX administration, its long-lasting alpha-2 adrenoceptor agonist effects can cause vasodilation and inhibition of sympathetic activity, leading to hypotension in some patients. Should that occur, ephedrine can be used to increase blood pressure, but it may also provoke transient coronary artery spasms and lead to VT. Consequently, extreme caution should be exercised in patients who develop hypotension following DEX administration. We also recognize the significance of regular training sessions, such as advanced cardiac life support programs.

Individualised analgesia, sedation, delirium and comfort management strategies in the ICU: a narrative review

This group is a product of the collaboration agreement signed by SOMIAMA (Sociedad de Medicina Intensiva de Madrid) and SAR MADRID (Sociedad de Anestesiología, Reanimación y Terapéutica del Dolor de Madrid) under which the organisations agreed to create joint working groups to improve critical patient care. Pain, discomfort, agitation, and delirium cause suffering, delay discharge, and can lead to serious complications in patients admitted to medical and surgical critical care units and post-anaesthesia care units. The main objectives in this type of unit include: Ensuring the comfort of patients suffering or recovering from a critical illness.Avoiding complications associated with the measures, particularly pharmacological, taken to ensure that comfort.

Reno-protective effects of perioperative dexmedetomidine in kidney transplantation: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND OBJECTIVE

There is currently no FDA-approved medical therapy for delayed graft function (DGF). Dexmedetomidine (DEX) has multiple reno-protective effects preventing ischemic reperfusion injury, DGF, and acute kidney injury. Therefore, we aimed to evaluate the reno-protective effects of perioperative DEX during renal transplantation.

METHODS

A systematic review and meta-analysis synthesizing randomized controlled trials (RCTs) from WOS, SCOPUS, EMBASE, PubMed, and CENTRAL until June 8th, 2022. We used the risk ratio (RR) for dichotomous outcomes and the mean difference for continuous outcomes; both presented with the corresponding 95% confidence interval (CI). We registered our protocol in PROSPERO with ID: CRD42022338898.

RESULTS

We included four RCTs with 339 patients. Pooled risk ratio found no difference between DEX and placebo in reducing DGF (RR: 0.58 with 95% CI [0.34, 1.01], p = 0.05) and acute rejection (RR: 0.88 with 95% CI [0.52, 1.49], p = 0.63). However, DEX improved short-term creatinine on day 1 (MD: - 0.76 with 95% CI [- 1.23, - 0.3], p = 0.001) and day 2 (MD: - 0.28 with 95% CI [- 0.5, - 0.07], p = 0.01); and blood urea nitrogen on day 2 (MD: - 10.16 with 95% CI [- 17.21, - 3.10], p = 0.005) and day 3 (MD: - 6.72 with 95% CI [- 12.85, - 0.58], p = 0.03).

CONCLUSION

Although there is no difference between DEX and placebo regarding reducing DGF and acute rejection after kidney transplantation, there may be some evidence that it has reno-protective benefits because we found statistically significant improvement in the short-term serum creatinine and blood urea nitrogen levels. More trials are required to investigate the long-term reno-protective effects of DEX.

Uncovering the Benefits of the Ketamine-Dexmedetomidine Combination for Procedural Sedation during the Italian COVID-19 Pandemic

This retrospective observational study evaluated the safety and efficacy of the ketamine and dexmedetomidine combination (keta-dex) compared to ketamine or dexmedetomidine alone for sedation of patients with acute respiratory distress due to COVID-19 pneumonia who require non-invasive ventilation. The following factors were assessed: tolerance to the ventilation, sedation level on the Richmond Agitation-Sedation Scale (RASS), hemodynamic and saturation profile, adverse effects, and discontinuation or mortality during ventilation. The study included 66 patients who underwent sedation for non-invasive ventilation using keta-dex (KETA-DEX group, n = 22), ketamine (KET group, n = 22), or dexmedetomidine (DEX group, n = 22). The DEX group showed a slower sedation rate and a significant reduction in blood pressure compared to the KETA-DEX group (p < 0.05). An increase in blood pressure was recorded more frequently in the KET group. No reduction in oxygen saturation and no deaths were observed in any of the groups. None of the patients discontinued ventilation due to intolerance. The mean duration of sedation was 28.12 h. No cases of delirium were observed in any of the groups. Overall, keta-dex was associated with faster sedation rates and better hemodynamic profiles compared to dexmedetomidine alone. Keta-dex is effective and safe for sedation of uncooperative patients undergoing non-invasive ventilation.

Dexmedetomidine for the prevention of delirium in adults admitted to the intensive care unit or post-operative care unit: A systematic review of randomised clinical trials with meta-analysis and Trial Sequential Analysis

OBJECTIVES

To assess any benefit or harm, we conducted a systematic review of randomised clinical trials (RCTs) allocating adults to dexmedetomidine versus placebo/no intervention for the prevention of delirium in intensive care or post-operative care units.

DATA SOURCES

We searched Medline, Embase, CENTRAL and other databases. The last search was 9 April 2022.

DATA EXTRACTION

Literature screening, data extraction and risk of bias volume 2 assessments were performed independently and in duplicate. Primary outcomes were occurrences of serious adverse events (SAEs), delirium and all-cause mortality. We used meta-analysis, Trial Sequential Analysis, and GRADE (Grading Recommendations Assessment, Development and Evaluation).

DATA SYNTHESIS

Eighty-one RCTs (15,745 patients) provided data for our primary outcomes. Results from trials at low risk of bias showed that dexmedetomidine may reduce the occurrence of the most frequently reported SAEs (relative risk [RR] 0.69; 95% CI 0.43-1.09), cumulated SAEs (RR 0.70; 95% CI 0.52-0.95) and the occurrence of delirium (RR 0.62; 95% CI 0.43-0.89). The certainty of evidence was very low for delirium. Mortality was very low in trials at low risk of bias (0.4% in the dexmedetomidine groups and 1.0% in the control groups) and meta-analysis did not provide conclusive evidence that dexmedetomidine may result in lower or higher all-cause mortality (RR 0.47; 95% CI 0.18-1.21). There was a lack of information from trial results at low risk of bias for all primary outcomes.

CONCLUSIONS

Trial results at low risk of bias showed that dexmedetomidine might reduce occurrences of SAEs and delirium, while no conclusive evidence was found for effects on all-cause mortality. The certainty of evidence ranged from very low for occurrence of delirium to low for the remaining outcomes.

Emergency Palliative Cancer Care: Dexmedetomidine Treatment Experiences-A Retrospective Brief Report on Nine Consecutive Cases

INTRODUCTION

Dexmedetomidine, an alpha-2 adrenergic receptor agonist with potential opioid sparing properties, is utilized in palliative medicine, but the knowledge base for this practice is limited. We describe concomitant use of dexmedetomidine and opioids in an acute palliative care unit.

METHODS

We included all hospitalized palliative cancer care patients treated with dexmedetomidine from January 2019 to January 2021. Demographics, opioid doses, dexmedetomidine indications and dosing, reported effects and adverse responses, as well as treatment lengths were recorded.

RESULTS

Three women and six men aged 42-66 years with metastatic cancer and Eastern Cooperative Oncology Group (ECOG) performance status I-IV used dexmedetomidine and opioids concomitantly. Indications for dexmedetomidine were pain (n = 7) and anxiety (n = 2). Dexmedetomidine was administered intravenously in two patients and subcutaneously in seven. All administrations were continuous infusions; initial doses ranged from 240 to 1344 µg/24 h with later doses from 240 to 2440 µg/24 h. Physicians reported relief from pain and anxiety, but two patients required neuraxial pain management during admission. At day 2 of dexmedetomidine treatment, the opioid dose was reduced in six out of nine patients. For all patients with available data at day 7, mean opioid dose was reduced to 74% of the initial dose. When excluding the two patients requiring neuraxial pain management, the corresponding number was 80%. Two patients had transient hypotension, but dexmedetomidine was well tolerated and in no cases withdrawn due to adverse effects. Mean dexmedetomidine treatment length was 40 days.

CONCLUSIONS

Dexmedetomidine treatment decreased opioid consumption and was well tolerated in a retrospective study of nine palliative cancer care patients. It may represent a treatment option late in the disease trajectory.

Real-time evaluation of the independent analgesic efficacy of dexmedetomidine

BACKGROUND

Dexmedetomidine has analgesic properties, but the intraoperative analgesic effect of dexmedetomidine is often masked by the effects of other general anaesthetics. Therefore, the degree to which it reduces intraoperative pain intensity remains unclear. The objective of this double-blind, randomised controlled trial was to evaluate the independent intraoperative analgesic efficacy of dexmedetomidine in real-time.

METHODS

This single-centre study enrolled 181 patients who were hospitalised for below-knee orthopaedic surgeries between 19 January 2021 to 3 August 2021 were eligible for this is single-centre study. Peripheral neural block was performed on patients scheduled for below-knee orthopaedic surgeries. Patients were randomly assigned to the dexmedetomidine or midazolam group and were intravenously administered with 1.5 µg kg^-1 h^-1 dexmedetomidine or 50 µg kg^-1 h^-1 midazolam, respectively. The analgesic efficacy was evaluated using the real-time non-invasive nociception monitoring. The primary endpoint was the attainment rate of the nociception index target. The secondary endpoints included the occurrence of intraoperative hypoxemia, haemodynamic parameters, the consciousness index, electromyography and patient outcomes.

RESULTS

On Kaplan-Meier survival analysis, the defined nociception index target was attained in 95.45% and 40.91% of patients receiving dexmedetomidine and midazolam, respectively. Log-rank analysis revealed that the dexmedetomidine group attained the nociception index target significantly faster and the median attainment time of the nociception index target in the dexmedetomidine group was 15 min. Dexmedetomidine group was associated with a significantly lower incidence of hypoxemia. There was no significant difference in blood pressure between the dexmedetomidine and midazolam groups. Further, the dexmedetomidine group had a lower maximum visual analogue scale score and lower analgesic consumption postoperatively.

CONCLUSIONS

Dexmedetomidine has independent analgesia and systemically administered as an adjuvant agent has better analgesic efficacy than midazolam without severe side effects.

TRIAL REGISTRATION

clinicaltrial.gov Registry Identifier: NCT-04675372.Registered on 19/12 /2020.

Analgesic, cardiorespiratory effects and motor block characteristics of epidural levobupivacaine alone or in combination with methadone or dexmedetomidine in bitches undergoing unilateral total mastectomy

The aim of this study was to evaluate the latency, extent of analgesia, and duration of motor block of levobupivacaine alone and combined with methadone or dexmedetomidine after epidural administration during and after mastectomy in dogs. Twenty-four mature, mixed-breed female dogs were randomly divided into three experimental groups with eight animals each, according to the agents used in lumbosacral epidural analgesia: levobupivacaine 0.75% alone (1.5mg/kg - control group), levobupivacaine 0.75% (1.5 mg/kg) + methadone 1% (0.3 mg/kg), or levobupivacaine 0.75% (1.5 mg/kg) + dexmedetomidine 0.05% (3 µg/kg). During surgery, cardiorespiratory parameters were evaluated. Rescue analgesia was given when there were signs of nociception and was necessary in all three treatment groups. Since all animals received rescue analgesia during the surgery and immediately post-surgery, the duration of the sensitive block were not evaluated. The extent of sensory block was between the 12º and 13º thoracic vertebrae for the control group, 7º thoracic vertebra to 5º lumbar vertebra (methadone group), and 8º thoracic vertebra to 4º lumbar vertebra for the dexmedetomidine group. Methadone or dexmedetomidine combined with levobupivacaine increased the extent of the sensory block and the duration of the motor block in bitches when administered via the epidural route.

Perioperative dexmedetomidine administration does not reduce the risk of acute kidney injury after non-cardiac surgery: a meta-analysis

BACKGROUND

Post-operative acute kidney injury (AKI) is one of the most common and serious complications after major surgery and is significantly associated with increased risks of morbidity and mortality. This meta-analysis was conducted to evaluate the effects of perioperative dexmedetomidine (Dex) administration on the occurrence of AKI and the outcomes of recovery after non-cardiac surgery.

METHODS

The PubMed, Embase, Web of Science, and Cochrane Library databases were systematically searched for studies comparing the effects of Dex vs. placebo on kidney function after non-cardiac surgery, and a pooled fixed-effect meta-analysis of the included studies was performed. The primary outcome was the occurence of post-operative AKI. The secondary outcomes included the occurence of intra-operative hypotension and bradycardia, intensive care unit (ICU) admission, duration of ICU stay, and hospital length of stay (LOS).

RESULTS

Six studies, including four randomized controlled trials (RCTs) and two observational studies, with a total of 2586 patients were selected. Compared with placebo, Dex administration could not reduce the odds of post-operative AKI (odds ratio [OR], 0.44; 95% confidence interval (CI), 0.18-1.06; P  = 0.07; I2  = 0.00%, P  = 0.72) in RCTs, but it showed a significant renoprotective effect (OR, 0.67; 95% CI, 0.48-0.95; P  = 0.02; I2  = 0.00%, P  = 0.36) in observational studies. Besides, Dex administration significantly increased the odds of intra-operative bradycardia and shortened the duration of ICU stay. However, there was no significant difference in the odds of intra-operative hypotension, ICU admission, and hospital LOS.

CONCLUSIONS

This meta-analysis suggests that perioperative Dex administration does not reduce the risk of AKI after non-cardiac surgery. However, the quality of evidence for this result is low due to imprecision and inconsistent types of non-cardiac operations. Thus, large and high-quality RCTs are needed to verify the real effects of perioperative Dex administration on the occurrence of AKI and the outcomes of recovery after non-cardiac surgery.

Dexmedetomidine attenuates renal ischemia-reperfusion injury through activating PI3K/Akt-eNOS signaling via α2 adrenoreceptors in renal microvascular endothelial cells

Renal microvascular endothelial cells (RMECs), which are closely related to regulation of vascular reactivity and modulation of inflammation, play a crucial role in the process of renal ischemia and reperfusion (I/R) injury. Previous studies have reported the protective effects of dexmedetomidine (DEX) against renal I/R injury, but little is known about the role of DEX on RMECs. This study aimed to investigate whether DEX alleviated renal I/R injury via acting on the RMECs. Mice underwent bilateral renal artery clamping for 45 min followed by reperfusion for 48 h, and the cultured neonatal mice RMECs were subjected to hypoxia for 1 h followed by reoxygenation (H/R) for 24 h. The results suggest that DEX alleviated renal I/R injury in vivo and improved cell viability of RMECs during H/R injury in vitro. Gene sequencing revealed that the PI3K/Akt was the top enriched signaling pathway and the endothelial cells were widely involved in renal I/R injury. DEX activated phosphorylation of PI3K and Akt, increased eNOS expression, and attenuated inflammatory responses. In addition, the results confirmed the distribution of α₂ adrenoreceptor (α₂ -AR) in RMECs. Furthermore, the protective effects of DEX against renal I/R injury were abolished by α₂ -AR antagonist (atipamezole), which was partly reversed by the PI3K agonist (740 Y-P). These findings indicated that DEX protects against renal I/R injury by activating the PI3K/Akt-eNOS pathway and inhibiting inflammation responses via α₂ -AR in RMECs.

Use of dexmedetomidine in patients with sepsis: a systematic review and meta-analysis of randomized-controlled trials

Background

Dexmedetomidine is widely used in patients with sepsis. However, its effect on septic patients remains controversial. The objective of this study was to summarize all randomized controlled trials (RCTs) examining dexmedetomidine use in sepsis patients.

Methods

This systematic review and meta-analysis included RCTs comparing dexmedetomidine with other sedatives in adult sepsis patients. We generated pooled relative risks (RRs) and standardized mean differences and performed trial sequential analysis and a cumulative meta-analysis. The primary outcome was mortality, and the secondary outcomes were the length of the intensive care unit stay, duration of mechanical ventilation, number of ventilation-free days, incidence of total adverse event, incidence of delirium, and levels of interleukin 6, tumor necrosis factor alpha, and alanine aminotransferase.

Results

We included 19 RCTs that enrolled 1929 patients. Compared with other sedatives, dexmedetomidine decreased the all-cause mortality (RR 0.83; 95% confidence interval [CI] [0.69, 0.99]) and inflammatory response (interleukin 6 and tumor necrosis factor alpha levels at 24 h: standardized mean difference (SMD) − 2.15; 95% CI [− 3.25, − 1.05] and SMD − 1.07, 95% CI [− 1.92, − 0.22], respectively). Trial sequential analysis showed that it is not up to required information size. The overall risk adverse events was similar between dexmedetomidine and the other sedatives (RR 1.27, 95% CI [0.69, 2.36]), but dexmedetomidine increased the risk of arrhythmias (RR 1.43, 95% CI [0.59, 3.51]). Length of intensive care unit stay (SMD − 0.22; 95% CI [− 0.85, − 0.41]), duration of mechanical ventilation (SMD 0.12; 95% CI [− 1.10, 1.35]), incidence of delirium (RR 0.98; 95% CI [0.72, 1.33]), and levels of alanine aminotransferase and creatinine at 24 h were not significantly reduced.

Conclusions

Dexmedetomidine in sepsis patients could significantly reduce mortality compared with benzodiazepines but not with propofol. In addition, dexmedetomidine can significantly decrease inflammatory response in patients with sepsis compared with other sedatives. Dexmedetomidine might lead to an increased incidence of arrhythmias, but its safety profile did not show significant differences in the incidence of total adverse events. Future RCTs are needed to determine the sepsis patient population that would benefit most from dexmedetomidine and its optimal dosing regimen.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-022-01052-2.

Effect of Perioperative Dexmedetomidine on Delayed Graft Function Following a Donation-After-Cardiac-Death Kidney Transplant: A Randomized Clinical Trial

IMPORTANCE

Delayed graft function (DGF) is a risk factor for acute rejection and graft failure after kidney transplant. Previous studies have suggested that dexmedetomidine may be renoprotective, but whether the use of dexmedetomidine would improve kidney allograft function is unknown.

OBJECTIVE

To investigate the effects of perioperative dexmedetomidine on DGF following a donation-after-cardiac-death (DCD) kidney transplant.

DESIGN, SETTING, AND PARTICIPANTS

This single-center, double-blind, placebo-controlled randomized clinical trial was conducted at The First Affiliated Hospital of Soochow University in Suzhou, China. Adults (18 years or older) who were scheduled for DCD kidney transplant were enrolled between September 1, 2019, and January 28, 2021, and then randomized to receive either dexmedetomidine or normal saline (placebo). One-year postoperative outcomes were recorded. All analyses were based on the modified intention-to-treat population.

INTERVENTIONS

Patients who were randomized to the dexmedetomidine group received a 24-hour perioperative dexmedetomidine intravenous infusion (0.4 μg/kg/h intraoperatively and 0.1 μg/kg/h postoperatively). Patients who were randomized to the normal saline group received an intravenous infusion of the placebo with the same dose regimen as the dexmedetomidine.

MAIN OUTCOMES AND MEASURES

The primary outcome was the incidence of DGF, defined as the need for dialysis in the first posttransplant week. The prespecified secondary outcomes were in-hospital repeated dialysis in the first posttransplant week, in-hospital acute rejection, and serum creatinine, serum cystatin C, estimated glomerular filtration rate, need for dialysis, and patient survival on posttransplant day 30.

RESULTS

Of the 114 patients enrolled, 111 completed the study (mean [SD] age, 43.4 [10.8] years; 64 male patients [57.7%]), of whom 56 were randomized to the dexmedetomidine group and 55 to the normal saline group. Dexmedetomidine infusion compared with normal saline reduced the incidence of DGF (17.9% vs 34.5%; odds ratio [OR], 0.41; 95% CI, 0.17-0.98; P = .04) and repeated dialysis (12.5% vs 30.9%; OR, 0.32; 95% CI, 0.13-0.88; P = .02, which was not statistically significant after multiple testing corrections), without significant effect on other secondary outcomes. Dexmedetomidine vs normal saline infusion led to a higher median (IQR) creatinine clearance rate on postoperative days 1 (9.9 [4.9-21.2] mL/min vs 7.9 [2.0-10.4] mL/min) and 2 (29.6 [9.7-67.4] mL/min vs 14.6 [3.8-45.1] mL/min) as well as increased median (IQR) urine output on postoperative days 2 (106.5 [66.3-175.6] mL/h vs 82.9 [27.1-141.9] mL/h) and 7 (126.1 [98.0-151.3] mL/h vs 107.0 [82.5-137.5] mL/h) and at hospital discharge discharge (110.4 [92.8-121.9] mL/h vs 97.1 [77.5-113.8] mL/h). Three patients (5.5%) from the normal saline group developed allograft failure by the post hoc 1-year follow-up visit.

CONCLUSIONS AND RELEVANCE

This randomized clinical trial found that 24-hour perioperative dexmedetomidine decreased the incidence of DGF after DCD kidney transplant. The findings support the use of dexmedetomidine in kidney transplants.

TRIAL REGISTRATION

Chinese Clinical Trial Registry Identifier: ChiCTR1900025493.

Intravenous versus perineural dexmedetomidine in prolongation of analgesia with regional anesthesia: a meta-analysis and systematic review

Background and Objective. It is unclear whether perineural administration offers advantages when compared to intravenous dexmedetomidine in local anesthesia. To compare the efficacy of perineural versus intravenous dexmedetomidine as local anesthetic adjuvant, we conducted the meta analysis and systematic review. Materials and Methods. Two researchers searched MEDLINE, OVID, PubMed, Embase, Cochrane Central, Web of Science and Wanfang data for randomized controlled trials comparing the effect of intravenous versus perineural dexmedetomidine as local anesthetic adjuvant without any language restrictions. Results. We identified 14 randomized controlled trials (801 patients). The results revealed that the duration of analgesia (SMD: -1.76, 95 % CI, [-2.7, -0.83] P = 0.000, I2 = 96 %), the duration of sensory block (SMD:- 3.99, 95 % CI, [-5.88, -2.0], P = 0.000, I2 = 97.6 %), the duration of motor block (SMD: -1.6, 95 % CI, [-2.78, -0.41] P = 0.008, I 2 = 95.5 %) were significantly longer in the perineural group, when compared to systematic dexmedetomidine. The onset time of sensory block (SMD: 1.55, 95 % CI, [0.16, 2.94] P = 0.028, I2 = 96.7 %) and the onset time of motor block (SMD: 0.84, 95 % CI, [0.17, 1.5] P = 0.013, I2 = 88.3 %) were shorter in perineural group compared to intrave nous dexmedetomidine. Meanwhile, analgesic consumption in 24 hours (SMD: 0.37, 95 % CI, [0.05, 0.69] P = 0.023, I 2 = 55.6 %) and the incidence of patients of Ramsay Sedation Scale > 3 (RR: 3.8, 95 % CI, [1.45, 9.97] P = 0.000, I 2 = 26.9 %), hypotension (RR: 1.74, 95 % CI, [1.15, 2.65] P= 0.009, I2 = 32.7 %) and bradycardia (RR: 3.71, 95 % CI, [1.27, 10.86] P = 0.017, I2 = 0 %) were lower in perineural dexmedetomidine compared to the intravenous group. Conclusions. Our meta-analysis generates the evidence that perineural dexmedetomidine is a superior adminstration for prolonging the duration of analgesia. Perineural dexmedetomidine also shows the advantages in duration of sensory block and the onset time of sensory and motor block, when compared to the intravenous administration. Simultaneously, dexmedetomidine as a local anesthetic adjuvant for perineural injection may be much safer than intravenous application because of the lower incidence of patients of Ramsay Sedation Scale > 3 and lower incidence of hypotension and bradycardia.

Dexmedetomidine as an Analgesic Agent with Neuroprotective Properties: Experimental and Clinical Aspects

Dexmedetomidine (Dexdor or Precedex®) is considered as a sedative agent which is widely used as an adjuvant in general anesthesia and critical care practice. There is extensive evidence indicating its neuroprotective properties especially in various ischemic and hemorrhagic brain injury models of animals. Clinical trials have shown that dexmedetomidine (DEX) can improve the outcome of intensive care unit (ICU) patients. Also, DEX is appropriate as a non-opioid analgesic therapy whenever minimizing opioid-related side effects is necessary. The present article reviews the recent advances in the use of DEX as a neuroprotective agent in both animal and human studies including newest findings about the mechanism of the drug as well as analgesic efficacy of this drug at all perioperative stages. In spite of the beneficial effects of the drug on the nervous system, there are potential adverse effects, such as hypotension and bradycardia, which can be treated pharmacologically and must be taken into consideration by clinicians.

Ambulatory Anesthesia for a Case of Idiopathic Bronchiolitis Obliterans

Bronchiolitis obliterans is rarely described in the nonlung transplant anesthesia literature. This case report describes a 27-year-old female patient with idiopathic bronchiolitis obliterans and dental anxiety who safely received intravenous deep sedation using diphenhydramine, dexmedetomidine, and ketamine in an ambulatory community dental clinic. This report outlines the anesthetic plan developed following a thorough preoperative assessment and review of the key anesthetic considerations of idiopathic bronchiolitis obliterans (eg, potential respiratory complications and appropriateness for the ambulatory dental environment) and discusses the careful anesthetic management of this patient using deep sedation to facilitate comprehensive restorative dentistry.

Perioperative dexmedetomidine and 5-year survival in patients undergoing cardiac surgery

BACKGROUND

Dexmedetomidine sedation has been associated with favourable outcomes after surgery. We aimed to assess whether perioperative dexmedetomidine use is associated with improved survival after cardiac surgery.

METHODS

This retrospective cohort study included 2068 patients undergoing on-pump coronary artery bypass grafting and/or valve surgery. Among them, 1029 patients received dexmedetomidine, and 1039 patients did not. Intravenous dexmedetomidine infusion of 0.007 μg kg^-1 min^-1 was initiated before or immediately after cardiopulmonary bypass and lasted for < 24 h. The primary outcome was 5-year survival after cardiac surgery. The propensity scores matching (PSM), inverse probability of treatment weighting (IPTW), and overlap weighting approaches were used to minimise bias. Survival analyses were performed with Cox proportional-hazard models.

RESULTS

The median age was 63 yr old and the male to female ratio was 71:29 in both groups. Baseline covariates were balanced between groups after adjustment using PSM, IPTW, or overlap weighting. Patients receiving dexmedetomidine in cardiac surgical procedures had higher survival during postoperative 5 yr in unadjusted analysis (hazard ratio [HR]=0.63; 95% confidence interval [CI], 0.51-0.78; P<0.001), and after adjustment with PSM (HR=0.63; 95% CI, 0.45-0.89; P=0.009), IPTW (HR=0.70; 95% CI, 0.51-0.95; P=0.023), or overlap weighting (HR=0.67; 95% CI, 0.51-0.89; P=0.006). The 5-yr mortality rate after cardiac surgery was 13% and 20% in the dexmedetomidine and non-dexmedetomidine groups, respectively (PSM adjusted odds ratio=0.61; 95% CI, 0.42-0.89; P=0.010).

CONCLUSION

Perioperative dexmedetomidine infusion was associated with improved 5-yr survival in patients undergoing cardiac surgery.

Effect of supplemental dexmedetomidine in interventional embolism on cerebral oxygen metabolism in patients with intracranial aneurysms

Objective

To investigate the effect of supplemental dexmedetomidine in interventional embolism on cerebral oxygen metabolism in patients with intracranial aneurysms.

Methods

Ninety patients who underwent interventional embolism of intracranial aneurysms were equally divided into Group A and Group B. In Group A, dexmedetomidine was injected intravenously 10 minutes before inducing anesthesia, with a loading dose of 0.6 µg/kg followed by 0.4 µg/kg/hour. Group B received the same amount of normal saline by the same injection method. Heart rate (HR), mean arterial pressure (MAP), arterial–jugular venous oxygen difference [D(a-jv) (O₂)], cerebral oxygen extraction [CE (O₂)], and intraoperative propofol use were recorded before inducing anesthesia (T₀) and at five time points thereafter.

Results

The amount of propofol in Group A was lower vs Group B. At all five time points after T₀, HR, MAP, D(a-jv) (O₂), and CE (O₂) in Group A were significantly lower vs Group B, with significant differences for jugular venous oxygen saturation (S_jvO₂) and the oxygen content of the internal jugular vein (C_jvO₂) between the groups.

Conclusion

Dexmedetomidine resulted in less intraoperative propofol, lower D(a-jv) (O₂) and CE (O₂), and improved cerebral oxygen metabolism.

Dexmedetomidine decreased the post-thyroidectomy bleeding by reducing cough and emergence agitation - a randomized, double-blind, controlled study

Background

Bleeding after thyroidectomy occurs due to violent coughing during emergence. Dexmedetomidine is helpful for the smooth emergence and suppression of cough. The purpose of the present study was to compare the effects of dexmedetomidine on postoperative bleeding after thyroidectomy.

Methods

Randomized, double-blind, controlled trials were conducted in female patients (ASA I–II, aged 20 to 60 years). The patients were randomly allocated into two groups. Approximately 15 min before the end of the surgery, dexmedetomidine was administered (0.6 µg/kg/h) without a loading dose in group D (n = 69), and normal saline was administered in group S (n = 70) at the same infusion rate. Hemodynamic data, coughing reflex, extubation time, Ramsay sedation scale (RSS), and recovery time were assessed during the administration of the study drugs and recovery from anesthesia. The amount of postoperative hemorrhage was measured for 3 days.

Results

Data from a total of 139 patients were analyzed. The incidence of severe cough was significantly lower in group D than in group S (4.3 % vs. 11.5 %, P = 0.022). The emergence agitation in the postanesthetic care unit was significantly lower in group D than in group S (P = 0.01). Postoperative bleeding was significantly lower in group D than in group S until the second postoperative day (P = 0.015).

Conclusions

Dexmedetomidine can be helpful in decreasing bleeding after thyroidectomy by reducing coughing and emergence agitation.

Trial registration

This study was registered at http://clinicaltrials.gov (registration number NCT02412150, 09/04/2015).

Hemodynamic Management of Patients with Ejection Fraction < 50% Undergoing Pulmonary Vein Ablation

There is no consensus regarding optimal methodology forblood pressure monitoring inpatients with a depressed ejection fraction undergoingcatheter ablationfor atrial fibrillation. Our goalswere to determine ifhemodynamicmanagementdifferences exist during radiofrequency ablation for atrial fibrillation in patients with and without an ejection fraction< 50%, and whether management was influenced by the utilization of invasive arterial blood pressure monitoring. This single-center trial retrospectively compared blood pressure management during catheterablation of atrial fibrillationin all patients with an ejection fraction< 50% over a 2-year span (n=44), and compared to an age-matched cohort with preserved ejection fraction ablated over the same span in time (n=44). Blood pressure was not significantly managed differently between the groups, and did not appear to be influenced by the use of invasive arterial blood pressure monitoring.Hemodynamic management is similar across the spectrum of ejection fraction, regardless of invasive arterial blood pressure monitoring, which challenges the need for invasive arterial blood pressure monitoringduringcatheter ablation ofatrial fibrillationin left ventricular systolic dysfunction.

Dexmedetomidine Attenuates Ischemia/Reperfusion-Induced Myocardial Inflammation and Apoptosis Through Inhibiting Endoplasmic Reticulum Stress Signaling

Background

Endoplasmic reticulum stress (ERS)-mediated myocardial inflammation and apoptosis plays an important role in myocardial ischemia/reperfusion (I/R) injury. Dexmedetomidine has been used clinically with sedative, analgesic, and anti-inflammatory properties. This study aimed to determine the effects of dexmedetomidine pretreatment on inflammation, apoptosis, and the expression of ERS signaling during myocardial I/R injury.

Methods

Rats underwent myocardial ischemia for 30 min and reperfusion for 6 h, and H9c2 cardiomyocytes were subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) injury (OGD for 12 h and reoxygenation for 3 h). Dexmedetomidine was administered prior to myocardial ischemia in rats or ODG in cardiomyocytes. In addition, the α2-adrenergic receptor antagonist (yohimbine) or the PERK activator (CCT020312) was given prior to dexmedetomidine treatment.

Results

Dexmedetomidine pretreatment decreased serum levels of cardiac troponin I, reduced myocardial infarct size, alleviated histological structure damage, and improved left ventricular function following myocardial I/R injury in rats. In addition, dexmedetomidine pretreatment increased cell viability and reduced cytotoxicity following OGD/R injury in cardiomyocytes. Mechanistically, the cardioprotection offered by dexmedetomidine was mediated via the inhibition of inflammation and apoptosis through downregulating the expression of the ERS signaling pathway, including glucose-regulated protein 78 (GRP78), protein kinase R-like endoplasmic reticulum kinase (PERK), C/EBP homologous protein (CHOP), inositol-requiring protein 1 (IRE1), and activating transcription factor 6 (ATF6). Conversely, the protective effects of dexmedetomidine were diminished by blocking the α2 adrenergic receptors with yohimbine or promoting PERK phosphorylation with CCT020312.

Conclusion

Dexmedetomidine pretreatment protects the hearts against I/R injury via inhibiting inflammation and apoptosis through downregulation of the ERS signaling pathway. Future clinical studies are needed to confirm the cardioprotective effects of dexmedetomidine in patients at risk of myocardial I/R injury.

Critical Review and Meta-Analysis of Postoperative Sedation after Adult Cardiac Surgery: Dexmedetomidine Versus Propofol

OBJECTIVE

To evaluate reports from the published literature of all randomized clinical trials (RCT) comparing postoperative sedation with dexmedetomidine versus propofol in adult patients, after open cardiac surgery.

DESIGN

A computerized search on Medline, EMBASE, Web of Science, and Agency for Healthcare Research and Quality databases was completed through June 2020. Meta-analysis of all published RCT comparing dexmedetomidine versus propofol utilization in the postoperative phase, using the standard Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist.

SETTING

Assemblage and critical discussion of 11 RCTs comparing postoperative sedation from standard published reports from 2003 to 2019.

PARTICIPANTS

The study comprised 1,184 patients and analyzed critical discussion of time-based parameters (time to extubation, intensive care unit length of stay, and hospital length of stay) and nontime-dependent factors (delirium, bradycardia, and hypotension).

MEASUREMENTS AND MAIN RESULTS

Time to extubation was significantly reduced in the dexmedetomidine group (standardized mean difference [SMD] = -0.70, 95% confidence interval [CI] -0.98 to -0.42, p < 0.001); however, no difference in mechanical ventilation time was observed (SMD = -0.72, 95% CI -1.60 to 0.15, N.S.). Dexmedetomidine significantly reduced the intensive care unit length of stay (SMD = 0.23, 95% CI -1.06 to -0.16, p = 0.008), but this did not translate into a reduced hospital length of stay (SMD = -1.13, 95% CI -2.43 to 0.16, N.S). For nontime-dependent factors, incidence of delirium was unaffected between groups (odds ratio [OR]: 0.68, 95% CI 0.43-1.06, N.S), and higher rates of bradycardia (OR: 3.39, 95% CI: 1.20-9.55, p = 0.020) and hypotension (OR: 1.68, 95% CI 1.09-2.58, p = 0.017) were reported with propofol.

CONCLUSIONS

Despite the ICU time advantages afforded by dexmedetomidine over propofol, the former did not seem to contribute to an overall reduction in hospital length of stay or improvement in postoperative outcomes of heart valve surgery and CABG patients.

Clinical and economic impact of the use of dexmedetomidine for sedation in the intensive care unit compared to propofol

Background Despite the advantages of dexmedetomidine (DEX) over propofol (PRO) including minimal respiratory depression and the potential for preventing and/or treating intensive care unit (ICU) delirium, PRO has been the preferred agent due to its lower cost. However, the acquisition cost of DEX has considerably decreased as a generic version of DEX has recently become available. Objective To evaluate clinical and economic outcomes of DEX-based sedation compared to PRO in the ICU. Setting A retrospective cohort study of 86 ICU patients who received either DEX or PRO for a period ≥ 12 h. Method Patients were matched by age, sex, and Sequential Organ Failure Assessment scores in a 1:1 ratio. Main outcome measure Clinical outcomes included the duration of mechanical ventilation (MV), ICU and hospital length of stay (LOS), and requirements of concomitant sedatives and opioids. Economic outcomes included the ICU and hospital costs as well as the cost of sedatives or combined sedatives and opioids per patient. Results There were no significant differences in ICU and hospital LOS and time on MV in both groups (median ICU LOS 7 [DEX] vs. 9 [PRO] days, p = 0.07; median hospital LOS 12 [DEX] vs. 14 [PRO] days, p = 0.261; median time of MV 144 [DEX] vs. 158 [PRO] hours, p = 0.176). DEX-based sedation compared to PRO was associated with similar ICU and hospital costs (US$ 67,561 vs. 78,429, p = 0.39; US$ 71,923 vs. 71,084, p = 0.1). Conclusion The clinical outcomes and economic impact associated with DEX- and PRO-based sedation were similar.

A prospective randomized double-blinded study of dexmedetomidine versus propofol infusion for orbital surgeries

PURPOSE

Orbital surgeries are traditionally taken up under general anesthesia. Local anesthesia combined with moderate sedation can also be considered as an alternative option. This study was performed to compare the safety and efficacy of dexmedetomidine and propofol infusion for orbital surgeries under local anesthesia.

METHODS

Twenty patients undergoing orbital surgery by a single surgeon were enrolled in this prospective randomized study. Selected patients were randomly administered dexmedetomidine (Group D) or propofol (Group P). Hemodynamic and respiratory effects, sedation levels, recovery profile, analgesic properties, and satisfaction levels of the patients and the surgeon were assessed.

RESULTS

There was a significant decrease in mean arterial pressures following drug administration compared to initial measurements in both the groups. However, a statistically significant decrease in heart rate was observed only in Group P. The sedation score at the end of loading dose was 3.3 ± 0.82 in Group D and 2.5 ± 0.52 in Group P and this difference was also statistically significant (P value-0.027). The surgeon's satisfaction score was 6.5 ± 0.71 in Group D and 5.6 ± 1.07 in Group P (P value - 0.045). There were no statistically significant differences observed in patients' satisfaction, pain, and anxiety scores in either group. No major hemodynamic changes or complications were noted in either of the groups.

CONCLUSION

Dexmedetomidine, in comparison to propofol, provides better sedation levels with good hemodynamic stability. It also offers better surgeon satisfaction, thus providing a useful alternative for general anesthesia in selective patients undergoing orbital surgery.

Feasibility of Patient-Controlled Sleep with Dexmedetomidine in Treating Chronic Intractable Insomnia

BACKGROUND

Patient-controlled analgesia (PCA) is an "on-demand" system which allows patients to self-administer intravenous medications in small bolus doses. Based on the principles of PCA, we developed Patient-Controlled Sleep (PCSL) for chronic intractable insomnia where the traditional analgesics in PCA were replaced with dexmedetomidine (Dex), an alpha-2 agonist widely used for premedication, sedation, anxiolysis and analgesia. The purpose of this study was to assess the feasibility of the new method for the treatment of chronic intractable insomnia.

PATIENTS AND METHODS

Patients with chronic intractable insomnia undergoing PCSL (n=20) were evaluated with the Pittsburgh Sleep Quality Index (PSQI), Symptom Checklist 90 (SCL-90), Hamilton Anxiety Scale (HAMA) and Hamilton Depression Scale (HAMD) before and after the treatment. The patient characteristics, overall outcomes and related side effects were also assessed.

RESULTS

Fifteen patients completed the treatment protocol. The duration of PCSL varied from a few days to four months, and the dosage of Dex gradually decreased without eliciting signs or symptoms of tolerance or physical dependence. The sleep quality improvement occurred immediately after the therapy in 12/15 patients, and of which, 7/12 patients achieved continuously improved sleep quality in follow-up.

CONCLUSION

PCSL with Dex might be a potential treatment for patients with chronic intractable insomnia. However, it is an off-label use, and the potential side effects of dexmedetomidine with long-term use needs further evaluation.

Effect of Intravenous Dexmedetomidine During General Anesthesia on Acute Postoperative Pain in Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Dexmedetomidine has been shown to have an analgesic effect. However, no consensus was reached in previous studies.

METHODS

Electronic databases such as PubMed, Embase, and Cochrane Central were searched for relevant randomized controlled trials. The relative risk and weighted mean difference (WMD) were used to analyze the outcomes. Random-effects model was used for meta-analysis.

RESULTS

Compared with the normal saline group, patients using DEX showed a significantly decreased pain intensity within 6 hours [WMD=-0.93; 95% confidence interval (CI), -1.34 to -0.53) and at 24 hours after surgery (WMD=-0.47; 95% CI, -0.83 to -0.11). DEX usage significantly reduced the cumulative opioids consumption at 24 hours after surgery (WMD=-6.76; 95% CI, -10.16 to -3.35), decreased the rescue opioids consumption in postanesthesia care unit (WMD=-3.11; 95% CI, -5.20 to -1.03), reduced the risk of rescue analgesics (relative risk=0.49; 95% CI, 0.33-0.71), and the interval to first rescue analgesia was prolonged (WMD=34.93; 95% CI, 20.27-49.59).

CONCLUSIONS

Intravenous DEX effectively relieved the pain intensity, extended the pain-free period, and decreased the consumption of opioids during postoperative recovery of adults in general anesthesia.

Dexmedetomidine post-treatment attenuates cardiac ischaemia/reperfusion injury by inhibiting apoptosis through HIF-1α signalling

Hypoxia‐inducible factor 1α (HIF‐1α) plays a critical role in the apoptotic process during cardiac ischaemia/reperfusion (I/R) injury. This study aimed to investigate whether post‐treatment with dexmedetomidine (DEX) could protect against I/R‐induced cardiac apoptosis in vivo and in vitro via regulating HIF‐1α signalling pathway. Rat myocardial I/R was induced by occluding the left anterior descending artery for 30 minutes followed by 6‐hours reperfusion, and cardiomyocyte hypoxia/reoxygenation (H/R) was induced by oxygen‐glucose deprivation for 6 hours followed by 3‐hours reoxygenation. Dexmedetomidine administration at the beginning of reperfusion or reoxygenation attenuated I/R‐induced myocardial injury or H/R‐induced cell death, alleviated mitochondrial dysfunction, reduced the number of apoptotic cardiomyocytes, inhibited the activation of HIF‐1α and modulated the expressions of apoptosis‐related proteins including BCL‐2, BAX, BNIP3, cleaved caspase‐3 and cleaved PARP. Conversely, the HIF‐1α prolyl hydroxylase‐2 inhibitor IOX2 partly blocked DEX‐mediated cardioprotection both in vivo and in vitro. Mechanistically, DEX down‐regulated HIF‐1α expression at the post‐transcriptional level and inhibited the transcriptional activation of the target gene BNIP3. Post‐treatment with DEX protects against cardiac I/R injury in vivo and H/R injury in vitro. These effects are, at least in part, mediated via the inhibition of cell apoptosis by targeting HIF‐1α signalling.

Efficacy of adjuvant dexmedetomidine in supraclavicular brachial plexus block for intractable complex regional pain syndrome: A case report with a 3-year follow-up

WHAT IS KNOWN AND OBJECTIVE

Pain management for complex regional pain syndrome (CRPS) is challenging. When added to local anaesthetics, dexmedetomidine prolongs the duration of the block and improves analgesia. The effect of long-term dexmedetomidine use in the brachial plexus block (BPB) for CRPS is unknown.

CASE DESCRIPTION

Here, we describe a case of satisfactory pain relief after supraclavicular BPB with dexmedetomidine every 1-3 months over 2 years (10 treatments), in a patient with severe upper extremity CRPS-related pain.

WHAT IS NEW AND CONCLUSION

Repeated, long-term, perineural administration of dexmedetomidine with BPB may be suitable for alleviating refractory CRPS pain.

Dexmedetomidine protects H9c2 cardiomyocytes against oxygen-glucose deprivation/reoxygenation-induced intracellular calcium overload and apoptosis through regulating FKBP12.6/RyR2 signaling

Purpose

Intracellular calcium ([Ca²⁺]i) overload is a major cause of cell injury during myocardial ischemia/reperfusion (I/R). Dexmedetomidine (DEX) has been shown to exert anti-inflammatory and organ protective effects. This study aimed to investigate whether pretreatment with DEX could protect H9c2 cardiomyocytes against oxygen-glucose deprivation/reoxygenation (OGD/R) injury through regulating the Ca²⁺ signaling.

Methods

H9c2 cardiomyocytes were subjected to OGD for 12 h, followed by 3 h of reoxygenation. DEX was administered 1 h prior to OGD/R. Cell viability, lactate dehydrogenase (LDH) release, level of [Ca²⁺]i, cell apoptosis, and the expression of 12.6-kd FK506-binding protein/ryanodine receptor 2 (FKBP12.6/RyR2) and caspase-3 were assessed.

Results

Cells exposed to OGD/R had decreased cell viability, increased LDH release, elevated [Ca²⁺]i level and apoptosis rate, down-regulated expression of FKBP12.6, and up-regulated expression of phosphorylated-Ser2814-RyR2 and cleaved caspase-3. Pretreatment with DEX significantly blocked the above-mentioned changes, alleviating the OGD/R-induced injury in H9c2 cells. Moreover, knockdown of FKBP12.6 by small interfering RNA abolished the protective effects of DEX.

Conclusion

This study indicates that DEX pretreatment protects the cardiomyocytes against OGD/R-induced injury by inhibiting [Ca²⁺]i overload and cell apoptosis via regulating the FKBP12.6/RyR2 signaling. DEX may be used for preventing cardiac I/R injury in the clinical settings.

Effects of peri-operative intravenous administration of dexmedetomidine on emergence agitation after general anesthesia in adults: a meta-analysis of randomized controlled trials

Objective

The aim of the current meta-analysis was to assess the effect of dexmedetomidine on emergence agitation (EA) and the recovery outcomes after general anesthesia in adults.

Methods

We searched the PubMed, the Cochrane Central Register of Controlled Trials, Embase, Web of Science and clinicaltrials.gov for relevant randomized controlled trials (RCTs) investigating the effects of dexmedetomidine on the EA in adults after general anesthesia compared with placebo. The primary outcome was the incidence of EA. Secondary outcomes included other recovery outcomes after general anesthesia.

Results

Twelve RCTs (842 participants) met the eligibility criteria. A conventional random-effects meta-analysis demonstrated that peri-operative intravenous dexmedetomidine could be effective for the prevention of EA [risk ratio (RR) 0.49, Trial Sequential Analysis (TSA)-adjusted 95% confidence interval (CI) 0.35–0.68, P<0.00001]. In addition, the TSA indicated that the meta-analysis for the incidence of EA reached the required information size (370). Lower number of patients receiving dexmedetomidine required analgesia (P=0.0009). Extubation time was longer (P=0.03) and hypotension (P=0.03) was more common with dexmedetomidine. Moreover, no difference was found in the other outcomes.

Conclusion

Dexmedetomidine was shown to effectively decrease the incidence of EA and to reduce postoperative analgesic requirements. Yet, other recovery outcomes including extubation time, length of PACU stay, postoperative residual sedation, hypotension, bradycardia as well as postoperative nausea and vomiting provided no data that could be used to form final conclusions.

Dexmedetomidine Use in a Case of Severe Cancer Pain

A 58-year-old male with chronic pancreatitis was seen by the palliative care service for pain and agitation related to a recent diagnosis of disseminated abdominal cancer. Increasing symptom burden, including pain and nausea, in the face of escalating doses of multiple opioid and sedative medications resulted in the addition of dexmedetomidine to successfully control his symptoms. Visceral sensitization related to his chronic pancreatitis likely increased his pain perception and required a multimodal approach to control his symptoms.

Effects of propofol, dexmedetomidine, and midazolam on postoperative cognitive dysfunction in elderly patients: a randomized controlled preliminary trial

Background:

Postoperative cognitive dysfunction (POCD) is a serious complication after surgery, especially in elderly patients. The anesthesia technique is a potentially modifiable risk factor for POCD. This study assessed the effects of dexmedetomidine, propofol or midazolam sedation on POCD in elderly patients who underwent hip or knee replacement under spinal anesthesia.

Methods:

The present study was a prospective randomized controlled preliminary trial. From July 2013 and December 2014, a total of 164 patients aged 65 years or older who underwent hip or knee arthroplasty at China-Japan Friendship Hospital and 41 non-surgical controls were included in this study. Patients were randomized in a 1:1:1 ratio to 3 sedative groups. All the patients received combined spinal-epidural anesthesia (CSEA) with midazolam, dexmedetomidine or propofol sedation. The sedative dose was adjusted to achieve light sedation (bispectral index[BIS] score between 70 and 85). All study participants and controls completed a battery of 5 neuropsychological tests before and 7 days after surgery. One year postoperatively, the patients and controls were interviewed over the telephone using the Montreal cognitive assessment 5-minute protocol.

Results:

In all, 60 of 164 patients (36.6%) were diagnosed with POCD 7 days postoperatively, POCD incidence in propofol group was significantly lower than that in dexmedetomidine and midazolam groups (18.2% vs. 40.0%, 51.9%, χ² = 6.342 and 13.603, P = 0.012 and < 0.001). When the patients were re-tested 1 year postoperatively, the incidence of POCD was not significantly different among the 3 groups (14.0%, 10.6% vs. 14.9%, χ² = 0.016 and 0.382, P = 0.899 and 0.536).

Conclusion:

Among dexmedetomidine, propofol and midazolam sedation in elderly patients, propofol sedation shows a significant advantage in term of short-term POCD incidence.

Dexmedetomidine for the prevention of delirium in critically ill patients - A protocol for a systematic review

BACKGROUND

Delirium is a common complication in critically ill patients and carries an increased risk of mortality and morbidity. Dexmedetomidine can potentially prevent delirium by diminishing predisposing factors. The evidence regarding the use of dexmedetomidine in preventing delirium is conflicting. This protocol aims to identify the beneficial and harmful effects of dexmedetomidine in the prevention of delirium.

METHODS

This protocol uses the recommendations of the Cochrane Collaboration, the Preferred Report Items of Systematic Reviews with Meta-Analysis Protocols, and the eight-step assessment procedure suggested by Jakobsen and colleagues. We wish to assess in critically ill patients, if dexmedetomidine versus placebo can reduce the incidence of delirium and improve clinical outcomes. We will include all randomised trials assessing the use of dexmedetomidine in the prevention of delirium. To identify trials, we will search the Cochrane Central Register of Controlled Trials, Medical Literature Analysis and Retrieval System Online, Excerpta Medica database, Latin American and Caribbean Health Sciences Literature, Science Citation Index Expanded on Web of Science, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, Chinese Science Journal Database, and BIOSIS. Two authors will screen the literature and extract data. We will use the Cochrane risk of bias tool to evaluate trials. Extracted data will be analysed using Review Manager 5 and Trial Sequential Analysis. We will create a "Summary of Findings"-table in which we will present our primary and secondary outcomes. We will assess the quality of evidence using GRADE.

DISCUSSION

This systematic review can potentially aid clinicians in decision-making and benefit the many critically ill patients at risk of delirium.

Dexmedetomidine for the management of delirium in critically ill patients-A protocol for a systematic review

BACKGROUND

Delirium is a common complication in critically ill patients and carries an increased risk of mortality and morbidity. Dexmedetomidine can potentially treat delirium by diminishing predisposing factors. The evidence regarding the use of dexmedetomidine in the management of delirium is conflicting. This protocol aims to identify the beneficial and harmful effects of dexmedetomidine in the management of delirium.

METHODS

This protocol uses the recommendations of the Cochrane Collaboration, the Preferred Report Items of Systematic reviews with Meta-Analysis Protocols, and the eight-step assessment procedure suggested by Jakobsen and colleagues. We wish to assess in critically ill patients with delirium, if dexmedetomidine vs placebo is effective in managing delirium and improving clinical outcomes. We will include all relevant randomised clinical trials assessing the use of dexmedetomidine in treating delirium. To identify trials, we will search the Cochrane Central Register of Controlled Trials, Medical Literature Analysis and Retrieval System Online, Excerpta Medica database, Latin American and Caribbean Health Sciences Literature, Science Citation Index Expanded on Web of Science, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, Chinese Science Journal Database, and BIOSIS. Two authors will screen the literature and extract data. The Cochrane risk of bias tool will be used to evaluate included trials. Extracted data will be analysed using Review Manager 5 and Trial Sequential Analysis. We will create a 'Summary of Findings'-table in which we will present our primary and secondary outcomes. We will assess the quality of evidence using GRADE assessment.

DISCUSSION

This systematic review can potentially aid clinicians in decision making and benefit the many critically ill patients developing delirium.

Dexmedetomidine as an Adjuvant to Local Anesthetics in Transversus Abdominis Plane Block: A Systematic Review and Meta-analysis

OBJECTIVES

The objective of this meta-analysis was to evaluate the analgesic effects of dexmedetomidine (DEX) in transversus abdominis plane (TAP) blocks for abdominal surgery.

METHODS

Electronic databases, including PubMed, EMBASE, Chinese National Knowledge Infrastructure (CNKI), Wan Fang, and the Cochrane Library, were conducted to collect the randomized controlled trials (RCTs) from inception to March 2018. RCTs investigating the impact of adding DEX to local anesthetics for TAP blocks were included in this analysis. Pain scores (at rest and movement), opioid consumption, the duration of the TAP block and the common adverse effects were analyzed.

RESULTS

Twenty published trials including 1212 patients met the inclusion criteria. The addition of DEX significantly reduced pain scores 8 hours postoperatively at rest (WMD, -0.78; 95% CI, -1.27 to -0.30; P=0.001), 4 hours postoperatively on movement (WMD, -1.13; 95% CI, -1.65 to -0.60; P<0.001), and opioid consumption (WMD, -13.71; 95% CI, -17.83 to -9.60; P<0.001) when compared with control group. Furthermore, perineural DEX significantly prolonged the duration of the TAP block (WMD, 3.33; 95% CI, 2.85 to 3.82; P<0.001). It did not affect the incidence of postoperative nausea and vomiting, hypotension, bradycardia, somnolence, or pruritus.

CONCLUSIONS

DEX is a potential anesthetic adjuvant that can facilitate better postoperative analgesia, reduce postoperative analgesic requirements, and prolong the local anesthetic effect when administered in TAP blocks.

Efficacy of Intra-articular Dexmedetomidine versus Buprenorphine for Postoperative Analgesia following Knee Arthroscopy: A Comparative Study

Background:

Arthroscopic knee surgery is most commonly performed minimally invasive surgical procedure in orthopaedics. Postoperative pain relief is must for early mobilisation that reduces patient's morbidity and improves postoperative recovery.

Aims and Objectives:

We sought to compare analgesic efficacy of intraarticular buprenorphine with dexmedetomidine following arthroscopic surgery of knee.

Settings and Design:

A prospective , randomized controlled double blinded study was conducted involving 60 patients undergoing arthroscopic knee surgery.

Materials and Methods:

Patients were allocated into group B (n = 30) and group D (n = 30) receiving 100 μg of intraarticular buprenorphine and 100 μg of intraarticular dexmedetomidine respectively. Parameters observed were the time to first rescue analgesia , the number of patients requiring rescue analgesia with in next 24 hours, Visual analogue scale (VAS) at rest and on mobilization at 1^st, 2^nd, 4^th, 8^th, 12^th and 24^th hour.

Statistical Analysis:

Quantitative data were analyzed by unpaired student's t test and categorical data by Fisher's exact test. A P < 0.05 was considered to be significant. Statistical analysis was done using Statistical Package for the Social Sciences (SPSS 19.0, SPSS Inc., Chicago, IL, USA).

Results:

Time to first rescue analgesia was significantly longer in patients receiving in group B. VAS scores at rest were comparable between the groups at 1^st, 2^nd, 4^th and 8^th hour but significantly low with intraarticular buprenorphine than intraarticular dexmedetomidine at 12^th and 24^th hour. VAS scores on ambulation were comparable at 1^st, 2^nd and 4^th hour but significantly higher in dexmedetomidine group as compared to buprenorphine at 8^th, 12^th and 24^th hour.

Conclusion:

Intraarticular buprenorphine 100 μg provides longer duration of analgesia with decreased postoperative rescue analgesic requirement as compared to 100 μg intraarticular dexmedetomidine.

An analysis of the survival impact of dexmedetomidine in children undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy

OBJECTIVE

Recent evidence suggests the α2-adrenoreceptor agonist dexmedetomidine may promote metastasis of cancer cells. In this study we sought to evaluate the impact of dexmedetomidine administration on the survival of children and adolescents with cancer.

DESIGN

Retrospective chart review.

SETTING

Comprehensive cancer center.

PATIENTS

Children and adolescents who had undergone cytoreductive surgery with hyperthermic intraperitoneal chemotherapy for peritoneal carcinomatosis.

INTERVENTION

Intraoperative and/or early postoperative (within 24 hours of surgery) administration of dexmedetomidine.

MEASUREMENTS

Multivariable cox proportional hazard models were used to assess the association between dexmedetomidine administration and progression free survival (PFS) or overall survival (OS).

MAIN RESULTS

Ninety-three patients were identified. The median age was 12 years, 42% were female, and 35% received dexmedetomidine. There were no significant differences between the baseline and perioperative characteristics of patients who received dexmedetomidine and those who did not. In the multivariable analysis, the administration of dexmedetomidine was not associated with PFS (HR = 1.20, 95% CI [0.60-2.41], p = .606) or OS (HR = 0.81, 95% CI [0.35-1.85], p = .611).

CONCLUSION

In this retrospective study of children and adolescents who had undergone a major oncologic surgery, the intraoperative and/or early postoperative administration of dexmedetomidine was not associated with survival.

Replacement of dexmedetomidine loading with midazolam for sedation in elderly patients with spinal anesthesia

BACKGROUND

Dexmedetomidine is an effective sedative during spinal anesthesia. However, it requires a loading dose, which can result in transient hypertension, hypotension, bradycardia, and/or sinus arrest. In addition, the time required to reach an appropriate depth of sedation may cause anxiety to the patients. Therefore, we examined whether an intravenous bolus of midazolam could replace the loading dose of dexmedetomidine for sedation during surgery in elderly patients who received spinal anesthesia.

METHODS

Patients aged over 60 years who scheduled to undergo total knee arthroplasty under spinal anesthesia were enrolled in this study. The patients were randomized into 2 groups. Patients in dexmedetomidine group (group D) (n = 20) were administered a loading dose of dexmedetomidine (1.0 μg/kg over 10 min) intravenously followed by dexmedetomidine maintenance (0.5 μg/kg/h). Patients in group MD (n = 20) were administered an intravenous midazolam (0.05 mg/kg) followed by dexmedetomidine maintenance (0.5 μg/kg/h) intravenously. Heart rate (HR), mean arterial blood pressure (MBP), peripheral oxygen saturation (SpO2), and patient state index (PSI) were recorded. Ramsay sedation scale (RSS) scores were evaluated at 10 minutes after drug administration and the end of surgery.

RESULTS

A total of 40 subjects were enrolled in the present study. At baseline, there was no between-group difference in HR. Ten minutes after drug administration, group D had lower HR than group MD (62.1 ± 9.4 versus 69.6 ± 13.4, P = .047). PSI was significantly lower in group MD at 10 minutes after drug administration (82.8 ± 13.0 versus 72.0 ± 16.0, P = .024); there was no between-group difference at 30 and 60 minutes, and lower values in group D at the end of surgery (70.2 ± 22.6 versus 79.7 ± 10.9, P = .011). The RSS score showed statistically significantly deeper sedation in group MD 10 minutes after drug administration, but no difference at the end of surgery.

CONCLUSIONS

An intravenous bolus of midazolam is a viable alternative to dexmedetomidine loading for sedation during surgery in elderly patients who received spinal anesthesia. This is especially effective for patients who are at high risk for bradycardia or who want a faster sedation.