Dexmedetomidine: a review of its use for sedation in mechanically ventilated patients in an intensive care setting and for procedural sedation

Dexmedetomidine in the emergency department: A prospective observational cohort study

BACKGROUND

Dexmedetomidine (DEX) is a centrally acting sympatholytic sedative. Abundant evidence from the intensive care unit and other settings demonstrates that the use of DEX is associated with improved sedation-related outcomes. There is a paucity of data on the use and efficacy of DEX in the emergency department (ED).

METHODS

We performed a prospective single-center observational cohort study of patients treated with intravenous DEX for any indication in the ED. We performed serial bedside evaluations of sedation depth and delirium and administered standardized questionnaires to ED physicians about their use of DEX. We assessed the incidence of hemodynamic adverse events (HAEs; bradycardia or hypotension), clinically significant HAEs (HAEs accompanied by clinical intervention or discontinuation of DEX), sedation-related ED outcomes, and clinician perception of DEX effectiveness.

RESULTS

We enrolled 75 patients treated with DEX in the ED during our study period. The most common indication for DEX was noninvasive positive pressure ventilation (32 patients, 43%). DEX was administered in the ED for a median of 2.6 h (interquartile range [IQR] 1.6-4.9 h), with a median infusion rate of 0.3 μg/kg/h (IQR 0.2-0.4 μg/kg/h). Clinically significant HAE occurred in nine patients (12%, 95% CI 6%-22%). Other sedative or analgesic infusions were administered in the ED to 21 patients (28%). Clinicians felt DEX was highly effective (median [IQR] effectiveness score of 5 [3-5] on a 5-point Likert scale). The median (IQR) ED Richmond Agitation Sedation Scale post-DEX was -1 (-4 to 0).

CONCLUSIONS

DEX is used in the ED for diverse indications. Additional data from larger cohorts and comparative studies are required to determine the precise incidence of clinically significant HAE associated with DEX use in the ED. ED clinicians have a positive perception of the effectiveness of DEX.

Efficacy and safety of sedation with dexmedetomidine in adults undergoing gastrointestinal endoscopic procedures: systematic review and meta-analysis of randomized controlled trials

Background: The sedative role of dexmedetomidine (DEX) in gastrointestinal endoscopic procedures is unclear. We performed this systematic review and meta-analysis to assess the efficacy and safety of sedation with DEX during gastrointestinal endoscopic procedures with a view to providing evidence-based references for clinical decision-making. Methods: The PubMed, Embase, Cochrane Library, Web of Science, and ClinicalTrials.gov databases were searched for randomized controlled trials (RCTs) that compared DEX with different sedatives comparators (such as propofol, midazolam, and ketamine) for sedation in a variety of adult gastrointestinal endoscopic procedures from inception to 1 July 2022. Standardized mean difference (SMD) and weighted mean difference (WMD) with 95% confidence interval (CI) or pooled risk ratios (RR) with 95% CI were used for continuous outcomes or dichotomous outcomes, respectively, and a random-effect model was selected regardless of the significance of the heterogeneity. Results: Forty studies with 2,955 patients were assessed, of which 1,333 patients were in the DEX group and 1,622 patients were in the control (without DEX) group. The results suggested that the primary outcomes of sedation level of DEX are comparable to other sedatives, with similar RSS score and patient satisfaction level, and better in some clinical outcomes, with a reduced risk of body movements or gagging (RR: 0.60; 95% CI: 0.37 to 0.97; p = 0.04; I2 = 68%), and a reduced additional requirement for other sedatives, and increased endoscopist satisfaction level (SMD: 0.41; 95% CI: 0.05 to 0.77; p = 0.03; I2 = 86%). In terms of secondary outcomes of adverse events, DEX may benefit patients in some clinical outcomes, with a reduced risk of hypoxia (RR:0.34; 95% CI: 0.20 to 0.55; p < 0.0001; I2 = 52%) and cough (RR: 0.25; 95% CI: 0.12 to 0.54; p = 0.0004; I2 = 0%), no significant difference in the risk of hypotension, while an increased risk of bradycardia (RR: 3.08; 95% CI: 2.12 to 4.48; p < 0.00001; I2 = 6%). Conclusion: This meta-analysis indicates that DEX is a safe and effective sedative agent for gastrointestinal endoscopy because of its benefits for patients in some clinical outcomes. Remarkably, DEX is comparable to midazolam and propofol in terms of sedation level. In conclusion, DEX provides an additional option in sedation for gastrointestinal endoscopic procedures. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/#searchadvanced.

Anesthetic management of airway stent placement by rigid bronchoscopy with superior laryngeal nerve block while preserving spontaneous breathing: A case report

Key Clinical Message

The combination of superior laryngeal nerve block can reduce the respiratory depression that occurs during management under total intravenous anesthesia.

Abstract

Anesthetic management of endobronchial stent placement by rigid bronchoscopy requires the maintenance of spontaneous breathing while suppressing upper airway reflexes. The combination of superior laryngeal nerve block (SLNB) can reduce the respiratory depression that occurs during management under total intravenous anesthesia. The patient was diagnosed as having lung cancer with invasion into the right middle bronchus and stenosis of the right main bronchus on chest computed tomography, and emergency airway stent placement was performed. Sedation was initiated with propofol and dexmedetomidine, and ultrasound-guided SLNB was performed after local anesthetic spraying into the oral cavity and trachea. Bucking was minimally controlled during insertion of the rigid bronchoscope. The patient's intraoperative hemodynamics remained stable, and there were no hypoxic events. SLNB can provide the suppression of the upper airway reflex while minimizing effects on spontaneous breathing, and may be useful for achieving balanced anesthesia during rigid bronchoscopy.

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.

Neuronal connected burst cascades bridge macroscale adaptive signatures across arousal states

The human brain displays a rich repertoire of states that emerge from the microscopic interactions of cortical and subcortical neurons. Difficulties inherent within large-scale simultaneous neuronal recording limit our ability to link biophysical processes at the microscale to emergent macroscopic brain states. Here we introduce a microscale biophysical network model of layer-5 pyramidal neurons that display graded coarse-sampled dynamics matching those observed in macroscale electrophysiological recordings from macaques and humans. We invert our model to identify the neuronal spike and burst dynamics that differentiate unconscious, dreaming, and awake arousal states and provide insights into their functional signatures. We further show that neuromodulatory arousal can mediate different modes of neuronal dynamics around a low-dimensional energy landscape, which in turn changes the response of the model to external stimuli. Our results highlight the promise of multiscale modelling to bridge theories of consciousness across spatiotemporal scales.

A retrospective comparative study of anesthesia with remimazolam and remifentanil versus dexmedetomidine and remifentanil for transcatheter aortic valve replacement

Remimazolam, an ultrashort-acting benzodiazepine, allows for rapid and reliable arousal. Rapid awakening using remimazolam may be beneficial in transcatheter aortic valve replacement (TAVR), as it allows rapid detection of neurologic deficits. The purpose of this study was to compare arousal time and outcomes between monitored anesthesia care (MAC) with remimazolam and remifentanil and conventional MAC with dexmedetomidine, propofol, and remifentanil. This study was a single center retrospective study. All TAVR cases performed under MAC (MAC-TAVR) at our institution between 2019 and 2021 were included. Patients were classified by anesthesia method into remimazolam and dexmedetomidine groups. Among 258 MAC-TAVR patients, 253 were enrolled. After propensity score matching, 76 patients were assigned to each group. The time from end of drug-administration to arousal [20.0 (16.0, 24.0) min vs. 38.5 (30.0, 56.3) min, p < 0.0001] and the time from attempted-arousal to arousal [1.0 (1.0, 1.0) min vs. 12.5 (3.0, 26.8) min, p < 0.0001] were significantly shorter in the remimazolam group. There was no significant difference in the length of ICU stay [2.0 (2.0, 2.0) days vs. 2.0 (2.0, 2.0) days, p = 0.157] and postoperative hospital stay [6.0 (4.0, 9.0) days vs. 5.0 (4.0, 8.0) days, p = 0.262].Trial registration: Clinical trial number: R03-123, Registry URL: https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000051635 Registration number: UMIN000045195, Principal investigator's name: Atsuhiro Kitaura, Date of registration: 20 August 2021.

Effect of dexmedetomidine combined with local infiltration analgesia on postoperative wound complications in patients with total knee arthroplasty: A meta-analysis

Dexmedetomidine has been demonstrated to be effective in the management of pain in total knee replacement (TKA). Nevertheless, a combination of a local anaesthetic and a dose of dexmedetomidine might be a better choice for post-operative pain management of TKA. The aim of this research is to determine if the combination of a local anaesthetic with dexmedetomidine during a knee replacement operation can decrease the post-operation pain. Furthermore, the effectiveness and security of dexmedetomidine combined with topical anaesthetic were evaluated for the management of post-operative TKA. Based on the research results, the author made a research on the basis of four big databases. The Cochrane Handbook on Intervention Systems Evaluation has also evaluated the quality of the literature. Seven randomized controlled trials have been established from this. It was found that the combination of local anaesthesia and dexmedetomidine had a greater effect on postoperative pain in 4 h (mean difference [MD], -0.9; 95% CI, -1.71, -0.09; p = 0.03), 8 h (MD, -0.52; 95% CI, -0.66, -0.38; p < 0.0001), 12 h (MD, -0.72; 95% CI, -1.04, -0.40; p < 0.0001), 24 h (MD, -0.49; 95% CI, -0.83, -0.14; p = 0.006), 48 h (MD, -0.51; 95% CI, -0.92, -0.11; p = 0.01). Nevertheless, because of the limited number of randomized controlled trials covered by this meta-analysis, caution should be exercised with regard to data treatment. More high quality research will be required to confirm the results.

Pharmacological pain and sedation interventions for the prevention of intraventricular hemorrhage in preterm infants on assisted ventilation - an overview of systematic reviews

BACKGROUND

Germinal matrix hemorrhage and intraventricular hemorrhage (GMH-IVH) may contribute to neonatal morbidity and mortality and result in long-term neurodevelopmental sequelae. Appropriate pain and sedation management in ventilated preterm infants may decrease the risk of GMH-IVH; however, it might be associated with harms.

OBJECTIVES

To summarize the evidence from systematic reviews regarding the effects and safety of pharmacological interventions related to pain and sedation management in order to prevent GMH-IVH in ventilated preterm infants.

METHODS

We searched the Cochrane Library August 2022 for reviews on pharmacological interventions for pain and sedation management to prevent GMH-IVH in ventilated preterm infants (< 37 weeks' gestation). We included Cochrane Reviews assessing the following interventions administered within the first week of life: benzodiazepines, paracetamol, opioids, ibuprofen, anesthetics, barbiturates, and antiadrenergics. Primary outcomes were any GMH-IVH (aGMH-IVH), severe IVH (sIVH), all-cause neonatal death (ACND), and major neurodevelopmental disability (MND). We assessed the methodological quality of included reviews using the AMSTAR-2 tool. We used GRADE to assess the certainty of evidence.

MAIN RESULTS

We included seven Cochrane Reviews and one Cochrane Review protocol. The reviews on clonidine and paracetamol did not include randomized controlled trials (RCTs) matching our inclusion criteria. We included 40 RCTs (3791 infants) from reviews on paracetamol for patent ductus arteriosus (3), midazolam (3), phenobarbital (9), opioids (20), and ibuprofen (5). The quality of the included reviews was high. The certainty of the evidence was moderate to very low, because of serious imprecision and study limitations. Germinal matrix hemorrhage-intraventricular hemorrhage (any grade) Compared to placebo or no intervention, the evidence is very uncertain about the effects of paracetamol on aGMH-IVH (risk ratio (RR) 0.89, 95% confidence interval (CI) 0.38 to 2.07; 2 RCTs, 82 infants; very low-certainty evidence); midazolam may result in little to no difference in the incidence of aGMH-IVH (RR 1.68, 95% CI 0.87 to 3.24; 3 RCTs, 122 infants; low-certainty evidence); the evidence is very uncertain about the effect of phenobarbital on aGMH-IVH (RR 0.99, 95% CI 0.83 to 1.19; 9 RCTs, 732 infants; very low-certainty evidence); opioids may result in little to no difference in aGMH-IVH (RR 0.85, 95% CI 0.65 to 1.12; 7 RCTs, 469 infants; low-certainty evidence); ibuprofen likely results in little to no difference in aGMH-IVH (RR 0.99, 95% CI 0.81 to 1.21; 4 RCTs, 759 infants; moderate-certainty evidence). Compared to ibuprofen, the evidence is very uncertain about the effects of paracetamol on aGMH-IVH (RR 1.17, 95% CI 0.31 to 4.34; 1 RCT, 30 infants; very low-certainty evidence). Compared to midazolam, morphine may result in a reduction in aGMH-IVH (RR 0.28, 95% CI 0.09 to 0.87; 1 RCT, 46 infants; low-certainty evidence). Compared to diamorphine, the evidence is very uncertain about the effect of morphine on aGMH-IVH (RR 0.65, 95% CI 0.40 to 1.07; 1 RCT, 88 infants; very low-certainty evidence). Severe intraventricular hemorrhage (grade 3 to 4) Compared to placebo or no intervention, the evidence is very uncertain about the effect of paracetamol on sIVH (RR 1.80, 95% CI 0.43 to 7.49; 2 RCTs, 82 infants; very low-certainty evidence) and of phenobarbital (grade 3 to 4) (RR 0.91, 95% CI 0.66 to 1.25; 9 RCTs, 732 infants; very low-certainty evidence); opioids may result in little to no difference in sIVH (grade 3 to 4) (RR 0.98, 95% CI 0.71 to 1.34; 6 RCTs, 1299 infants; low-certainty evidence); ibuprofen may result in little to no difference in sIVH (grade 3 to 4) (RR 0.82, 95% CI 0.54 to 1.26; 4 RCTs, 747 infants; low-certainty evidence). No studies on midazolam reported this outcome. Compared to ibuprofen, the evidence is very uncertain about the effects of paracetamol on sIVH (RR 2.65, 95% CI 0.12 to 60.21; 1 RCT, 30 infants; very low-certainty evidence). Compared to midazolam, the evidence is very uncertain about the effect of morphine on sIVH (grade 3 to 4) (RR 0.08, 95% CI 0.00 to 1.43; 1 RCT, 46 infants; very low-certainty evidence). Compared to fentanyl, the evidence is very uncertain about the effect of morphine on sIVH (grade 3 to 4) (RR 0.59, 95% CI 0.18 to 1.95; 1 RCT, 163 infants; very low-certainty evidence). All-cause neonatal death Compared to placebo or no intervention, the evidence is very uncertain about the effect of phenobarbital on ACND (RR 0.94, 95% CI 0.51 to 1.72; 3 RCTs, 203 infants; very low-certainty evidence); opioids likely result in little to no difference in ACND (RR 1.12, 95% CI 0.80 to 1.55; 5 RCTs, 1189 infants; moderate-certainty evidence); the evidence is very uncertain about the effect of ibuprofen on ACND (RR 1.00, 95% CI 0.38 to 2.64; 2 RCTs, 112 infants; very low-certainty evidence). Compared to midazolam, the evidence is very uncertain about the effect of morphine on ACND (RR 0.31, 95% CI 0.01 to 7.16; 1 RCT, 46 infants; very low-certainty evidence). Compared to diamorphine, the evidence is very uncertain about the effect of morphine on ACND (RR 1.17, 95% CI 0.43 to 3.19; 1 RCT, 88 infants; very low-certainty evidence). Major neurodevelopmental disability Compared to placebo, the evidence is very uncertain about the effect of opioids on MND at 18 to 24 months (RR 2.00, 95% CI 0.39 to 10.29; 1 RCT, 78 infants; very low-certainty evidence) and at five to six years (RR 1.6, 95% CI 0.56 to 4.56; 1 RCT, 95 infants; very low-certainty evidence). No studies on other drugs reported this outcome.

AUTHORS' CONCLUSIONS

None of the reported studies had an impact on aGMH-IVH, sIVH, ACND, or MND. The certainty of the evidence ranged from moderate to very low. Large RCTs of rigorous methodology are needed to achieve an optimal information size to assess the effects of pharmacological interventions for pain and sedation management for the prevention of GMH-IVH and mortality in preterm infants. Studies might compare interventions against either placebo or other drugs. Reporting of the outcome data should include the assessment of GMH-IVH and long-term neurodevelopment.

The use of dexmedetomidine in the emergency department: A systematic review

BACKGROUND

Dexmedetomidine (DEX), a centrally acting alpha-2 agonist, is increasingly used for sedation in multiple clinical settings. Evidence from the intensive care unit and operative settings suggests DEX may have significant advantages over traditional GABAergic sedatives such as benzodiazepines. There has been limited research on the use of DEX in the emergency department (ED).

METHODS

We performed a systematic review of the medical literature to identify all published evidence regarding the use of DEX in the ED. We included randomized and nonrandomized studies and studies reporting any use of DEX in the ED, even when it was not the primary focus of the study. Two authors reviewed studies for inclusion, and a single author assessed studies for quality and risk of bias and abstracted data.

RESULTS

We identified 35 studies meeting inclusion criteria, including 11 randomized controlled trials, 13 cohort and other nonrandomized studies, and 11 case reports and case series. Significant heterogeneity in interventions, comparators, indications, and outcomes precluded data pooling and meta-analysis. We found modest evidence that DEX was efficacious in facilitating medical imaging and mixed and limited evidence regarding its efficacy for procedural sedation and sedation of nonintubated medical and psychiatric patients. Our results suggested that DEX is associated with bradycardia and hypotension, which are generally transient and infrequently require medical intervention.

CONCLUSIONS

A limited body of generally poor- to moderate-quality evidence suggests that the use of DEX may be efficacious in certain clinical scenarios in the ED and that DEX use in the ED is likely safe. Further high-quality research into DEX use in the ED setting is needed, with a particular focus on clear and consistent selection of indications, identification of clear and clinically relevant primary outcomes, and careful assessment of the clinical implications of the hemodynamic effects of DEX therapy.

Pharmacologic Interventions to Prevent Delirium in Trauma Patients: A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials

To compare the relative efficacy of pharmacologic interventions in the prevention of delirium in ICU trauma patients.

DATA SOURCES

We searched Medical Literature Analysis and Retrieval System Online, Embase, and Cochrane Registry of Clinical Trials from database inception until June 7, 2022. We included randomized controlled trials comparing pharmacologic interventions in critically ill trauma patients.

STUDY SELECTION

Two reviewers independently screened studies for eligibility, extracted data, and assessed risk of bias.

DATA EXTRACTION

Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines for network analysis were followed. Random-effects models were fit using a Bayesian approach to network meta-analysis. Between-group comparisons were estimated using hazard ratios (HRs) for dichotomous outcomes and mean differences for continuous outcomes, each with 95% credible intervals. Treatment rankings were estimated for each outcome in the form of surface under the cumulative ranking curve values.

DATA SYNTHESIS

A total 3,541 citations were screened; six randomized clinical trials (n = 382 patients) were included. Compared with combined propofol-dexmedetomidine, there may be no difference in delirium prevalence with dexmedetomidine (HR 1.44, 95% CI 0.39-6.94), propofol (HR 2.38, 95% CI 0.68-11.36), nor haloperidol (HR 3.38, 95% CI 0.65-21.79); compared with dexmedetomidine alone, there may be no effect with propofol (HR 1.66, 95% CI 0.79-3.69) nor haloperidol (HR 2.30, 95% CI 0.88-6.61).

CONCLUSIONS

The results of this network meta-analysis suggest that there is no difference found between pharmacologic interventions on delirium occurrence, length of ICU stay, length of hospital stay, or mortality, in trauma ICU patients.

Dexmedetomidine Prolongs the Analgesic Effects of Periarticular Infiltration Analgesia following Total Knee Arthroplasty: A Prospective, Double-blind, Randomized Controlled Trial

BACKGROUND

Periarticular infiltration analgesia (PIA) is widely administered to relieve postoperative pain following total knee arthroplasty (TKA). The present study aimed to evaluate the effect of prolonging the analgesic duration by adding dexmedetomidine to PIA for pain management after TKA.

METHODS

One hundred and sixteen patients were randomly allocated into 3 groups based on PIA regimens including Group R (ropivacaine), Group E (ropivacaine plus epinephrine), and Group D (ropivacaine plus dexmedetomidine). The primary outcomes were postoperative visual analog scale (VAS) scores, time until the administration of first rescue analgesia, and opioid consumption. The secondary outcomes included postoperative inflammatory biomarkers and functional recovery. The tertiary outcomes were postoperative complications and adverse events.

RESULTS

The patients in Group D had significantly lower resting VAS scores than those in Groups R and E at 6 hours after surgery. Group R showed the higher pain scores at rest and motion than Groups D and E 12 hours postoperatively. The use of dexmedetomidine or epinephrine postponed the time until the administration of first rescue analgesia and led to lower opioid consumption in the first 24 hours after TKA. The levels of IL-8 and TNF-α in Groups D and E were significantly lower than those in Group R on postoperative Day 3. Furthermore, no significant differences were observed in functional recovery, postoperative complications, or adverse events among the three groups.

CONCLUSIONS

Adding dexmedetomidine as an adjuvant to PIA could potentiate and prolong the analgesic effect in the early stage following TKA without increasing the risk of adverse events.

The Effect of Two Different Dexmedetomidine Doses on the Prevention of Nausea and Vomiting in Discectomy Surgery under Spinal Anesthesia

Background

Considering the preventative effect of various medications on such complications after surgery, the present study evaluated the effect of two different dexmedetomidine doses on the prevention of nausea and vomiting in discectomy surgery.

Materials and Methods

The present controlled, double-blind clinical trial was performed on 135 patients that were candidates for discectomy surgery under spinal anesthesia, which were randomly allocated into three groups. Two different dexmedetomidine doses of 0.2 and 0.5 mcg/kg/h were intravenously administered using an infusion pump for 10 min in the first (DEX-0.2 group) and second (DEX-0.5 group) groups, respectively, with the third placebo group being used as a control group. Hemodynamic parameters, the severity of nausea and vomiting, and the incidence of complications were evaluated and recorded up to 24 h after surgery.

Results

The results of the present study revealed that, 20 min after the intervention, the severity of nausea and vomiting in the control group (with the mean of 1.95 ± 1.58) was significantly higher than that of the DEX-0.2 and DEX-0.5 groups with the means of 1.52 ± 1.11 and 1.27 ± 0.99, respectively (P = 0.010). In addition, no significant difference was found between the two dexmedetomidine doses in terms of the severity of nausea and vomiting (P > 0.05).

Conclusion

According to the results of the present study, a low dose of dexmedetomidine may be a more preferable choice as a preventive drug in the incidence of nausea and vomiting in discectomy surgery due to its lower complications, further reduction of nausea and vomiting, and more desirable hemodynamic stability.

Dexmedetomidine Sedation Combined With Remifentanil in MitraClip Procedures is Feasible and Improves Hemodynamics

OBJECTIVES

The objective of the study was to compare the overall feasibility, respiratory and hemodynamic stability, as well as process times of a dexmedetomidine-based sedative regimen compared with general anesthesia among patients undergoing MitraClip procedures.

DESIGN

A retrospective cohort study.

SETTING

A single tertiary care university center.

PARTICIPANTS

The study included 79 patients.

INTERVENTIONS

Dexmedetomidine sedation versus general anesthesia.

MEASUREMENTS AND MAIN RESULTS

Seventy-nine MitraClip procedures in dexmedetomidine/remifentanil conscious sedation (DCS, n = 26) or general anesthesia (GA, n = 53), performed between 2018 and 2020 at Charité - Universitätsmedizin Berlin, were analyzed retrospectively. Patients' median age was 81 years in both groups without differences in preinterventional EuroScore I (DCS 6 [5; 8], GA 7 [6; 8]) or systolic function (left ventricular ejection fraction: DCS 50% [32; 60] v. GA 50% [36; 60]; tricuspid annular plane systolic excursion: DCS 19 mm [16; 22] v GA 19 mm [15; 22]). During MitraClip procedures, respiratory parameters revealed no differences between groups, whereas patients under DCS showed higher mean arterial pressures (DCS 64 mmHg [59; 74] v GA 58 mmHg [53; 66]) and needed less norepinephrine (DCS 0.0µg/kg/min [0.0; 0.2] v GA 0.08 µg/kg/min [0.05; 0.15]). Emergence from both anesthesia regimens to readiness for intensive care unit transfer was faster in DCS (8 min [4; 18] v GA 16 min [11; 23]); however, total process time was comparable between groups (DCS 128 min [104; 155] v GA 142 min [117; 190]). Two patients required a switch from DCS to GA due to oral bleeding or prolonged procedure time. Both were excluded from the analysis. There was no switch to open surgery and no differences in postoperative complications between DCS and GA.

CONCLUSION

Dexmedetomidine/remifentanil sedation appears to be feasible and a safe option for MitraClip procedures, and provides better hemodynamic stability with faster emergence times compared with general anesthesia.

Dexmedetomidine in the treatment of toxicologic conditions: a systematic review and review of the toxicology investigators consortium database

INTRODUCTION

Dexmedetomidine is an alpha-2 adrenoceptor agonist which is widely used for sedation. Dexmedetomidine does not suppress the respiratory drive and produces a state of cooperative sedation; it may be associated with beneficial outcomes in the general critical care population. The role of dexmedetomidine in the treatment of toxicologic conditions (excluding alcohol withdrawal) is unclear.

OBJECTIVES

To critically assess and summarize the literature regarding the use of dexmedetomidine in toxicologic conditions other than alcohol withdrawal.

METHODS

We performed a systematic review of the medical literature to identify all existing evidence regarding the use of dexmedetomidine for toxicologic conditions. We excluded reviews and commentary, studies reporting exclusively on alcohol withdrawal, and studies reporting the use of dexmedetomidine to treat iatrogenic sedative withdrawal in the intensive care unit. We also performed a review of the Toxicology Investigators Consortium (ToxIC) database for patients treated with dexmedetomidine.

RESULTS

We identified 98 studies meeting inclusion criteria; 87 of these were case reports or case series, representing 99 unique cases. Eleven articles with other designs were identified, which included 138 patients treated with dexmedetomidine for toxicologic conditions. Ninety-three cases from the ToxIC registry met inclusion criteria. Common indications for dexmedetomidine included stimulant intoxication, sedative withdrawal, serotonin syndrome, antimuscarinic toxidrome, opioid withdrawal, and cannabinoid intoxication. Dexmedetomidine was usually administered by continuous infusion; bolus administration was reported in a minority of cases. Adverse effects were uncommon. The quality of evidence was generally low, given the preponderance of case reports, the rate of missing or poorly reported data, and the near-universal co-administration of other sedatives.

TREATMENT OF STIMULANT POISONING

Fifty-nine patients with stimulant poisoning were treated with dexmedetomidine. There was reasonably good evidence that dexmedetomidine was helpful in the treatment of stimulant poisoning.

TREATMENT OF SEDATIVE WITHDRAWAL

Twenty-two patients with sedative withdrawal were treated with dexmedetomidine. Several case reports of very high-quality suggested efficacy of dexmedetomidine for this indication, particularly for baclofen withdrawal.

TREATMENT OF SEROTONIN SYNDROME

Twenty-six patients with serotonin syndrome were treated with dexmedetomidine. This evidence was of lower quality due to missing clinical details, potential overdiagnosis of serotonin syndrome, and near-universal concomitant treatment with other sedatives.

TREATMENT OF ANTIMUSCARINIC POISONING

Forty-two patients with antimuscarinic poisoning were treated with dexmedetomidine. This evidence was of low quality and was limited by infrequent use of the preferred antidote, physostigmine.

TREATMENT OF OPIOID WITHDRAWAL

Forty-four patients with opioid withdrawal were treated with dexmedetomidine. This evidence was of low quality due to missing clinical details and near-universal concomitant treatment with other agents. The one high-quality trial reported the use of dexmedetomidine in ultra-rapid opioid detoxification, which is not indicated in modern practice.

TREATMENT OF CANNABINOID INTOXICATION

Five patients with cannabinoid intoxication were treated with dexmedetomidine. No definite conclusion can be drawn from the limited available evidence.

DISCUSSION

It is important to distinguish between the use of dexmedetomidine as a general sedative, which is likely to increase as the overall utilization of dexmedetomidine in critical care settings increases, and the use of dexmedetomidine as a specific pharmacologic treatment for a toxicologic condition. Well-established pharmacologic data from animal and human studies suggest dexmedetomidine counteracts stimulant-induced norepinephrine release. The mechanism by which dexmedetomidine treats sedative withdrawal is unclear. Some animal data show that dexmedetomidine may indirectly suppress serotonin release, which may suggest a role for dexmedetomidine in this condition.

CONCLUSIONS

There is a small and generally low-quality body of evidence which suggests that dexmedetomidine may be helpful in the treatment of certain toxicologic conditions, particularly stimulant intoxication and sedative withdrawal. Further high-quality research is needed to clarify the role of dexmedetomidine in patients with toxicologic conditions.

Dexmedetomidine Reduces Incidences of Ventricular Arrhythmias in Adult Patients: A Meta-Analysis

Purpose

To assess the antiarrhythmic properties of dexmedetomidine in patients in the intensive care unit.

Methods

A literature review was conducted with Ovid MEDLINE (R), Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Embase, and Scopus. Study Selection. Randomized controlled trials were included, examining the incidence of ventricular arrhythmias, ventricular tachycardia, or ventricular fibrillation with dexmedetomidine compared to placebo or an alternative sedative agent. For each publication that met the selection criteria, the patient demographics, incidence of arrhythmias, mortality, and adverse events were collected. Data extraction was carried out by two authors independently.

Results

We identified 6 out of 126 studies that met the selection criteria for our meta-analysis, all of which focused on the perioperative cardiac surgery period. Patients receiving dexmedetomidine demonstrated a significant reduction of the overall incidence of ventricular arrhythmias (RR 0.35, 95% CI 0.16, 0.76). In particular, dexmedetomidine significantly decreased the risk of ventricular tachycardia compared with control (RR 0.25, 95% CI 0.08, 0.80, I² 0%). Regarding adverse events, dexmedetomidine significantly increased the frequency of bradycardia (RR 2.78 95% CI 2.00, 3.87). However, there was no significant difference in mortality (RR 0.59 95% CI 0.12, 3.02).

Conclusion

From this meta-analysis, we report a decreased incidence of ventricular tachycardia with dexmedetomidine in critically ill patients. This result favors the use of dexmedetomidine for its antiarrhythmic properties.

The effect of intraoperative dexmedetomidine on cognitive dysfunction after surgery: a updated meta-analysis

BACKGROUND

Postoperative cognitive dysfunction (POCD) is one of the most common. Neuroprotective effects of dexmedetomidine (DEX) are reported in previous studies but evidence regarding the POCD is still unclear. In order to gain latest evidence, the present study analyzes the outcomes of randomized controlled trials (RCTs) which utilized DEX with general anaesthesia perioperatively.

METHOD

Four online databases (PubMed, Embase, the Cochrane Library, and CNKI) were used to find relevant RCTs to conduct systematic analysis. All studies comparing the incidence of POCD or MMSE score between the DEX group and the placebo or comparator group in patients undergoing general anaesthetic surgery were eligible for inclusion. Based on the inclusion and exclusion criteria, the studies were selected. This meta-analysis was performed using odds ratios (ORs) with 95% confidence intervals (CIs) for dichotomous data and standardized mean difference (SMD) and 95% CIs for continuous data as effective measures.

RESULTS

In total of 21 studies were included in this meta-analysis. The results showed that the incidence of POCD in DEX group was significantly lower than the control group on the first (OR = 0.36, 95% CI 0.24-0.54),third (OR = 0.45,95% CI 0.33-0.61) and seventh (OR = 0.40,95% CI 0.26-0.60) postoperative days; the MMSE scores in DEX group were higher than the control group on the first (SMD = 1.24, 95% CI 1.08-1.41), third(SMD = 1.09, 95%CI 0.94-1.24) and seventh (SMD = 3.28, 95% CI 1.51-5.04) postoperative days.

CONCLUSIONS

Intraoperative DEX use can ameliorate the POCD of patients who received surgical operations under general anesthesia, and effectively reduce the incidence of POCD and improve MMSE score.

Dexmedetomidine Directs T Helper Cells toward Th1 Cell Differentiation via the STAT1-T-Bet Pathway

Dexmedetomidine is an α2 adrenergic receptor agonist that has been reported to modulate the polarization of CD4+ T cells. However, the underlying mechanisms by which dexmedetomidine induces T-helper 1 (Th1) cell differentiation remain poorly understood. The aim of this study was to explore the potential mechanisms through which dexmedetomidine can induce Th1 cell differentiation. Purified CD4+ T cells were stimulated with anti-CD3/anti-CD28 and then treated with dexmedetomidine. Flow cytometry analysis was adopted to measure the concentration of Th1 cells. Enzyme-linked immunosorbent assay (ELISA) and real-time quantitative polymerase chain reaction (qPCR) were performed to detect protein levels and mRNA expression, respectively, of IFN-γ and IL-4. Western blotting was used to determine the phosphorylation of signal transducer and activator of transcription 1 (STAT1) and T-bet expression. The Th1 cell subset and IFN-γ levels were elevated in the dexmedetomidine-induced CD4+ T cells. Dexmedetomidine enhanced the phosphorylation of STAT1 and the expression of T-bet in the CD4+ T cells. Atipamezole (an α2 adrenergic antagonist) and fludarabine (a STAT1 inhibitor) reversed the dexmedetomidine-induced Th1 cell differentiation. These results suggested that dexmedetomidine induced Th1 cell differentiation via the STAT1-T-bet signaling pathway.

Efficacy of sedation with dexmedetomidine plus propofol during esophageal endoscopic submucosal dissection

BACKGROUND AND AIM

During endoscopic submucosal dissection for superficial esophageal cancer, patient body movement can sometimes occur, which may cause discontinuation of the procedure. Propofol and dexmedetomidine have recently been found to be useful sedatives for endoscopic submucosal dissection. This study investigated whether sedation using propofol plus dexmedetomidine can suppress the patient's body movements during esophageal endoscopic submucosal dissection and compared this combination with sedation using propofol alone.

METHODS

This was a prospective double-blind randomized controlled trial. Patients with superficial esophageal cancers who underwent esophageal endoscopic submucosal dissection at Yokohama City University Hospital were prospectively enrolled and were randomly assigned to the propofol and the propofol plus dexmedetomidine groups. The primary endpoint was the incidence of restlessness. The secondary endpoints were the satisfaction score, maintenance dose of propofol, and number of rescue propofol injections.

RESULTS

Sixty-six patients (propofol group: n = 33; combination group: n = 33) were included. The combination group had a significantly lower incidence of restlessness than the propofol group (3.0% vs 27.3%, P = 0.02). In the combination group, the satisfaction scores of the endoscopists were significantly higher, the maintenance dose of propofol was significantly lower, and the number of rescue propofol injections was lower than those in the propofol group (3.0% vs 18.2%, P < 0.001). Although the incidence of bradycardia was significantly higher in the combination group (30.3% vs 3.0%, P < 0.01), no serious adverse effects occurred.

CONCLUSION

The propofol plus dexmedetomidine combination provided excellent sedation that effectively suppressed the patient's body movements during esophageal endoscopic submucosal dissection.

Assessment and Management of Delirium in the Pediatric Intensive Care Unit: A Review

Many critically ill patients suffer from delirium which is associated with significant morbidity and mortality. There is a paucity of data about the incidence, symptoms, or treatment of delirium in the pediatric intensive care unit (PICU). Risk factors for delirium are common in the PICU including central nervous system immaturity, developmental delay, mechanical ventilation, and use of anticholinergic agents, corticosteroids, vasopressors, opioids, or benzodiazepines. Hypoactive delirium is the most common subtype in pediatric patients; however, hyperactive delirium has also been reported. Various screening tools are validated in the pediatric population, with the Cornell Assessment of Pediatric Delirium (CAPD) applicable to the largest age range and able to detect signs and symptoms consistent with both hypo- and hyperactive delirium. Treatment of delirium should always include identification and reversal of the underlying etiology, reserving pharmacologic management for those patients without symptom resolution, or with significant impact to medical care. Atypical antipsychotics (olanzapine, quetiapine, and risperidone) should be used first-line in patients requiring pharmacologic treatment owing to their apparent efficacy and low incidence of reported adverse effects. The choice of atypical antipsychotic should be based on adverse effect profile, available dosage forms, and consideration of medication interactions. Intravenous haloperidol may be a potential treatment option in patients unable to tolerate oral medications and with significant symptoms. However, given the high incidence of serious adverse effects with intravenous haloperidol, routine use should be avoided. Dexmedetomidine should be used when sedation is needed and when clinically appropriate, given the positive impact on delirium. Additional well-designed trials assessing screening and treatment of PICU delirium are needed.

Dexmedetomidine Inhibits ASIC Activity via Activation of α2A Adrenergic Receptors in Rat Dorsal Root Ganglion Neurons

Dexmedetomidine (DEX), a selective α₂ adrenergic receptor (α₂-AR) agonist, has been shown to have peripheral analgesic effects in a variety of pain conditions. However, the precise molecular mechanisms have not yet been fully elucidated. Acid sensing ion channels (ASICs) are the major player in pain associated with tissue acidosis. Given that both α₂-ARs and ASICs exist in dorsal root ganglia (DRG) neurons, we therefore investigated the effects of DEX on the functional activity of ASICs. Herein, whole-cell patch-clamp recordings demonstrated that DEX suppressed ASIC-mediated and acid-evoked currents and action potentials in dissociated rat DRG neurons. DEX shifted downwards concentration-response curve to protons, with a decrease of 35.83 ± 3.91% in the maximal current response to pH 4.5. DEX-induced inhibition of ASIC currents was blocked by the α_2A-AR antagonist BRL44408 in DRG neurons. DEX also inhibited ASIC3 currents in CHO cells co-expressing ASIC3 and α_2A-ARs, but not in ASIC3 transfected CHO cells without α_2A-ARs expression. DEX-induced inhibition of ASIC currents was mimicked by the protein kinase A inhibitor H-89, and blocked by intracellular application of the G_i/o protein inhibitor pertussis toxin and the cAMP analog 8-Br-cAMP. In addition, peripherally administration of DEX dose-dependently relieved nociceptive responses to intraplantar injection of acetic acid in rats through local α_2A-ARs. Our results indicated that DEX inhibited the functional activity of ASICs via α_2A-ARs and intracellular G_i/o proteins and cAMP/protein kinase A signaling pathway in rat DRG neurons, which was a novel potential mechanism that probably mediated peripheral analgesia of DEX.

Effect of age on dexmedetomidine treatment for ventilated patients with sepsis: a post-hoc analysis of the DESIRE trial

Aim

There are no definitive data to determine whether age influences the effects of dexmedetomidine (DEX) treatment. Thus, we investigated whether older age was associated with more favorable sedative action by DEX in sepsis patients who required mechanical ventilation.

Methods

This study involved a post‐hoc analysis of data from the Dexmedetomidine for Sepsis in the ICU Randomized Evaluation (DESIRE) trial. The patients were categorized based on median age into elderly and younger groups. The two groups were then compared during the first 7 days after ventilation based on proportion of patients with well‐controlled sedation (Richmond Agitation–Sedation Scale score between −3 and +1), days free from delirium (based on the Confusion Assessment Method for ICU), and days free from coma (Richmond Agitation–Sedation Scale score between −4 and −5).

Results

One hundred and one patients were assigned to the elderly group and 100 patients were assigned to the younger group. In the elderly group, 50 patients received DEX treatment and 51 patients received non‐DEX treatment, with the DEX arm having significantly better‐controlled sedation (range, 14–52% versus 16–27%; P = 0.01). In the younger group, 50 patients received DEX treatment and 50 patients received non‐DEX treatment, with no significant difference in the proportions of well‐controlled sedation (range, 20–64% versus 24–60%; P = 0.73). There were no significant differences in the numbers of days free from delirium or coma between the groups.

Conclusion

In elderly sepsis patients who require ventilation, dexmedetomidine could be more effective than other sedative agents for achieving proper sedation.

Delirium in the NICU: Risk or Reality?

Delirium is a frequent complication of critical illness in adult and pediatric populations and is associated with significant morbidity and mortality. Little is known about the incidence, risk, symptoms, or treatment of delirium in the NICU. Only 4 cases of NICU delirium have been reported, but many pediatric studies include infants. The Cornell Assessment of Pediatric Delirium tool has been validated in neonatal and infant populations for identification of delirium. Initial treatment should focus on identification and reversal of the cause, with pharmacologic management reserved for patients with symptoms that do not resolve or that significantly impact medical care. Routine use of intravenous haloperidol should be avoided because of the high incidence of serious adverse effects, but it may be considered in patients with significant symptoms who are unable to take oral medications. Atypical antipsychotics (olanzapine, quetiapine, and risperidone) appear to be efficacious with a low incidence of adverse effects. Risperidone has weight-based dosing and a liquid dosage form available, making it a good option for use in the NICU. Additional data from large cohorts of NICU patients routinely screened for delirium, and treated as indicated, are needed.

Comparison of Two Different Sedation Protocols during Transvaginal Oocyte Retrieval: Effects on Propofol Consumption and IVF Outcome: A Prospective Cohort Study

(1) Background: There has been various reports on the potential impact of anesthetic agents used during oocyte retrieval (OR) on the impairment of the capacity of the oocyte for fertilization and subsequent embryo quality; results have been conflicting; (2) Methods: The effects of two different sedation protocols during OR in two groups of patients undergoing In Vitro Fertilization/Intra-Cytoplasmic Sperm Injection IVF/ICSI, were compared on propofol consumption and on in vitro fertilization (IVF)/ICSI success. The study group received dexmedetomidine and fentanyl, while the control remifentanil and midazolam. In a prospective cohort study, we encompassed 72 cycles/patients. The administered dose of propofol per patient and fertilization rates were the primary outcomes, while anesthesiological parameters and IVF/ICSI outcomes were the secondary endpoints; (3) Results: We found a significant increase in propofol consumption in the study compared to the control group (77.0 ± 10.6 mg vs. 12.1 ± 6.1; p < 0.001), but fertilization rates were similar (p = 0.469). From the secondary anesthesiological outcomes, the post anesthesia discharge scores were better in the control group (15.0 (13.5 min) vs. 5.0 (10.0 min), p = 0.028). From the IVF/ICSI secondary outcome parameters, we found a higher quality of embryos on day three in the study compared to the control group (p = 0.040). The comparison of the other secondary outcomes yielded non-significant differences; (4) Conclusions: The use of dexmedetomidine, as an alternative agent during OR, was associated with higher propofol consumption as a rescue dose compared to remifentanil but was linked with similar fertilization rates and higher quality of embryos produced.

The hemodynamic effects of diazepam versus dexmedetomidine in the treatment of alcohol withdrawal syndrome: A randomized clinical trial

BACKGROUND

Dexmedetomidine (DEX) is an alpha-2 adrenergic drug used for short sedation and as an alternative to diazepam (DZP) in the treatment of alcohol withdrawal syndrome (AWS).

PURPOSE

This study aims to compare the hemodynamic effect of DZP versus DEX on heart rate (HR) and blood pressure in patients with AWS.

METHODS

Prospective randomized clinical trial that includes 40 patients with AWS from Mérida, Yucatán, México.

RESULTS

Forty patients were randomly divided into two groups: one group DZP (n=20) patients received diazepam (doses 5-20mg IV) and the other group (n=20) received DEX (dexmedetomidine infusion .2-.7mcg/kg/min). We obtained statistical significance in sedation with the DEX group in the degree of traumatic brain injury I/II (p=.003). The DEX group remained haemodynamically stable in the first 24h, the mean HR (73.85±8.39) was significant comparing both groups (p=.002). In the comparison of the figures for the DEX group with the DZP (143.85±2.30-137.95±5.62) the SBP was significant with a (p=.0001). Furthermore, DEX treatment was shorter.

CONCLUSION

Although DEX is not indicated for the routine treatment of AWS, this study proposes a positive effect on HR, SBP and fewer days of treatment compared to the standard DZP treatment for AWS. Clinical Trials.gov ID: NCT03877120-https://clinicaltrials.gov/ct2/show/NCT03877120.

Consensus Statement on Analgo-sedation in Neurocritical Care and Review of Literature

Aim and objective

Our main objective in developing this consensus is to bring together a set of most agreed-upon statements from a panel of global experts that would act as a guide for clinicians working in neurocritical care units (NCCUs).

Background

Given the physiological benefits of analgo-sedation in the NCCU, there is little information on their tailoring in the NCCU. This lack of evidence and guidelines on the use of sedation and analgesia in patients with neurological injury leads to a variation in clinical care based on patient requirements and institutional protocols.

Review results

Thirty-nine international experts agreed to be a member of this consensus panel. A Delphi method based on a Web-based questionnaire developed with Google Forms on a secure institute server was used to seek opinions of experts. Questions were related to sedation and analgesia in the neurocritical care unit. A predefined threshold of agreement was established as 70% to support any recommendation, strong, moderate, or weak. No recommendations were made below this threshold. Responses were collected from all the experts, summated, and expressed as percentage (%). After three rounds, consensus could be reached for 6 statements related to analgesia and 5 statements related to sedation. Consensus could not be reached for 10 statements related to analgesia and 5 statements related to sedation.

Conclusion

This global consensus statement may help in guiding practitioners in clinical decision-making regarding analgo-sedation in the NCCUs, thereby helping in improving patient recovery profiles.

Clinical significance

In the lack of high-level evidence, the recommendations may be seen as the current best clinical practice.

How to cite this article

Prabhakar H, Tripathy S, Gupta N, Singhal V, Mahajan C, Kapoor I, et al. Consensus Statement on Analgo-sedation in Neurocritical Care and Review of Literature. Indian J Crit Care Med 2021;25(2):126–133.

Low-dose intravenous dexmedetomidine reduces shivering following cesarean delivery: a randomized controlled trial

BACKGROUND

Intravenous dexmedetomidine 30 µg reduces shivering after cesarean delivery but can result in sedation and dry mouth. We hypothesized that prophylactic administration of 10 µg of IV dexmedetomidine would reduce the patient-reported severity of shivering after cesarean delivery, without an increased incidence of side effects.

METHODS

After institutional review board approval and informed written consent, women undergoing scheduled cesarean delivery with spinal or combined spinal-epidural anesthesia were randomized to receive either intravenous normal saline or dexmedetomidine 10 µg immediately after delivery. The primary outcome was a patient-rated subjective shivering score using a 10-cm visual analog scale at 30 and 60 min after arrival in the Post-Anesthesia Care Unit. Secondary outcomes included subjective scores for pain, nausea, itching, dry mouth, and sedation, as well as 24-h medication administration and investigator-rated observations of shivering, vomiting, pruritus, and sedation. Repeated measures ANOVA with Tukey-Kramer multiple-comparison test was applied for primary outcomes.

RESULTS

One hundred patients were enrolled, and 85 completed the study and were included in analysis. The mean ± SD shivering score in the dexmedetomidine group was significantly lower by repeated measures analysis than among controls across the first 60 min (P=0.0002), and individually at both 30 and 60 min (placebo 1.8 ± 2.6 vs. dexmedetomidine 0.6 ± 1.4 at 30 min; 1.2 ± 2.1 vs. 0.3 ± 0.6 at 60 min; both P <0.01). Patient-rated and observer-rated side effects did not significantly differ between groups.

CONCLUSIONS

Prophylactic administration of intravenous dexmedetomidine 10 µg after delivery reduces shivering without notable side effects.

Anesthetic considerations for tracheobronchial surgery

Tracheobronchial pathology can be related to trauma, infection, tumor, or a combination of these. Per definition, planning for tracheobronchial surgery can be complicated by the overlap of anesthesiological interests in airway management and the primary surgical field. Therefore, following a detailed description of the stenosis, management of tracheobronchial surgery requires an interdisciplinary discussion and individualized planning of the procedure. There are several options for intraoperative ventilation depending on the exact localization of the defect. Hence, different tubes and ventilation techniques from cross-field ventilation, to jet ventilation, or even spontaneous breathing under regional anesthesia, have to be discussed. Moreover, an innovative ventilation mode called flow-controlled ventilation (FVC) has been developed, which allows to apply standard tidal volumes through a narrow-bore endotracheal tube. In addition, the Ventrain has been developed as an emergency device following the same technique of an active expiration based on the Venturi principle and a controlled gas flow. In critical situations, it allows even ventilation through the working channel of a bronchoscope. Overall, tracheobronchial surgery is performed under total intravenous anesthesia and the aim of an early extubation at the end of surgery. Airway management has to be discussed and planned between surgeon and anesthesiologist. All of the steps of the procedure need constant and clear communication.

Effect of Intraoperative Dexmedetomidine on Postoperative Pain and Pulmonary Function Following Video-assisted Thoracoscopic Surgery

Context:

Acute postoperative pain following video-assisted thoracoscopic surgery (VATS) needs considerable attention, if untreated leads to chronic pain and postoperative lung dysfunction. Dexmedetomidine, α₂ adrenoceptor agonist has shown promising results of opioid-sparing effects.

Aims:

The objectives of this study are to investigate the effect of dexmedetomidine on postoperative analgesia and pulmonary mechanics in patients undergoing VATS.

Settings and Design:

This is a randomized controlled trial.

Subjects and Methods:

We conducted a prospective, randomized, double-blind study on lung cancer patients undergoing VATS. Each patient received either dexmedetomidine or comparable volume of normal saline during the intraoperative period. In the recovery unit, postoperative visual analog scale (VAS) score, rescue analgesic requirements, arterial blood gas values, and pulmonary function tests were recorded.

Statistical Analysis Used:

Data are analyzed using unpaired t-test, Mann–Whitney U-test, and Fischer's exact test. P < 0.05 was considered statistically significant.

Results:

VAS scores were significantly lower (P < 0.05) in the dexmedetomidine group at rest, on coughing and on mobilization from supine to sitting position. The partial pressure of arterial oxygen measured in postanesthesia care unit was significantly higher in the dexmedetomidine group (88 ± 8.2 vs 78 ± 9.1 mmHg). Forced expiratory volume in 1 was significantly greater in the dexmedetomidine group compared to the control group on the first 2 postoperative days (P < 0.05). The length of hospital stay was significantly reduced by dexmedetomidine.

Conclusions:

Intraoperative dexmedetomidine administration improves the quality of analgesia and postoperative lung function in patients undergoing VATS.

Multimorbidity and Critical Care Neurosurgery: Minimizing Major Perioperative Cardiopulmonary Complications

With increasing prevalence of chronic diseases, multimorbid patients have become commonplace in the neurosurgical intensive care unit (neuro-ICU), offering unique management challenges. By reducing physiological reserve and interacting with one another, chronic comorbidities pose a greatly enhanced risk of major postoperative medical complications, especially cardiopulmonary complications, which ultimately exert a negative impact on neurosurgical outcomes. These premises underscore the importance of perioperative optimization, in turn requiring a thorough preoperative risk stratification, a basic understanding of a multimorbid patient’s deranged physiology and a proper appreciation of the potential of surgery, anesthesia and neurocritical care interventions to exacerbate comorbid pathophysiologies. This knowledge enables neurosurgeons, neuroanesthesiologists and neurointensivists to function with a heightened level of vigilance in the care of these high-risk patients and can inform the perioperative neuro-ICU management with individualized strategies able to minimize the risk of untoward outcomes. This review highlights potential pitfalls in the intra- and postoperative neuro-ICU period, describes common preoperative risk stratification tools and discusses tailored perioperative ICU management strategies in multimorbid neurosurgical patients, with a special focus on approaches geared toward the minimization of postoperative cardiopulmonary complications and unplanned reintubation.

Comparison of dexmedetomidine with chloral hydrate as sedatives for pediatric patients: A systematic review and meta-analysis

BACKGROUND

Dexmedetomidine (Dex) and chloral hydrate (CH) are the most frequently used sedative agents in pediatric patients. We aimed to systematically review the literature comparing the efficacy and safety of Dex and CH for sedation in pediatric patients.

METHODS

Seven electronic databases and 3 clinical trial registry platforms were searched for articles published prior to October 2019. Randomized controlled trials (RCTs) evaluating the efficacy and safety of Dex versus CH for sedation in children were examined by 2 reviewers. The extracted information included the success rate of sedation, sedation latency, sedation duration, sedation recovery time, and adverse events. Moreover, the extracted data included 5 subgroups: the effects of 1, 1.5, 2, 2.5, and 3 μg/kg doses of Dex were compared with the effect of CH on the success rate of sedation. We also formed separate subgroups for different types of adverse events (incidence of vomiting, hypotension, bradycardia, etc). The outcomes were analyzed by Review Manager 5.3 software and are expressed as relative risks (RR) or the mean difference (MD) with the 95% confidence interval (CI). Heterogeneity was assessed with I-squared (I) statistics.

RESULTS

A total of 15 RCTs involving 2128 children with Dex versus CH for sedation were included in the meta-analysis. The dose range of Dex ranged from 1 to 3 μg/kg. Compared with CH, the Dex group had a significantly higher success rate of sedation (RR = 1.14, 95% CI [1.05, 1.25], I = 79%, P = .003). Additionally, subgroup analysis revealed that there was no significant difference in the success rate of sedation between the CH group and the 1, 1.5, 2.5, and 3 μg/kg Dex groups; only the 2 μg/kg Dex group had a significantly higher success rate than the CH group (RR = 1.15, 95% CI [1.03, 1.29], I = 80%, P = .02). There was no significant difference in the number of subjects who required 2 doses or the duration of sedation between the CH and Dex groups. Furthermore, compared with the Dex group, the CH group had a significantly longer sedation latency (MD = -3.54, 95% CI [-5.94, -1.15], I = 95%, P = .004), sedation recovery time (MD = -30.08, 95% CI [-46.77, -13.39], I = 99%, P = .0004), and total time from sedative administration to discharge (MD = -12.73, 95% CI [-15.48, -9.97], I = 0%, P < .05), as well as a higher number of adverse events in total (RR = 0.25, 95% CI [0.11, 0.61], I = 89%, P = .002). Moreover, the subgroup analysis of adverse events revealed that CH was associated with higher risks of vomiting (RR = 0.07, 95% CI [0.03, 0.17], I = 0%, P < .0001), crying or resisting (RR = 0.22, 95% CI [0.07, 0.71], I = 60%, P = .01), and cough (RR = 0.15, 95% CI [0.05, 0.44], I = 0%, P = .0006); there was no significant difference in the risk of hypotension, supplemental oxygen, or respiratory events between CH and Dex. However, Dex was associated with a higher risk of bradycardia (RR = 4.08, 95% CI [1.63, 10.21], I = 0%, P = .003).

CONCLUSIONS

Dex is an appropriate effective alternative to CH for sedation in pediatrics. However, considering the possibility of bradycardia, Dex should be used with caution.

Dexmedetomidine for Prolonged Sedation in the PICU: A Systematic Review and Meta-Analysis

OBJECTIVES

We aimed to systematically describe the use of dexmedetomidine as a treatment regimen for prolonged sedation in children and perform a meta-analysis of its safety profile.

DATA SOURCES

PubMed, EMBASE, Cochrane Library, Scopus, Web of Science, ClinicalTrials.gov, and CINAHL were searched from inception to November 30, 2018.

STUDY SELECTION

We included studies involving hospitalized critically ill patients less than or equal to 18 years old receiving dexmedetomidine for prolonged infusion (≥ 24 hr).

DATA EXTRACTION

Data extraction included study characteristics, patient demographics, modality of dexmedetomidine use, associated analgesia and sedation details, comfort and withdrawal evaluation scales, withdrawal symptoms, and side effects.

DATA SYNTHESIS

Literature search identified 32 studies, including a total of 3,267 patients. Most of the studies were monocentric (91%) and retrospective (88%); one was a randomized trial. Minimum and maximum infusion dosages varied from 0.1-0.5 µg/kg/hr to 0.3-2.5 µg/kg/hr, respectively. The mean/median duration range was 25-540 hours. The use of a loading bolus was reported in eight studies (25%) (range, 0.5-1 µg/kg), the mode of weaning in 11 (34%), and the weaning time in six of 11 (55%; range, 9-96 hr). The pooled prevalence of bradycardia was 2.6% (n = 10 studies; 14/387 patients; 95% CI, 0.3-7.3; I = 75%), the pooled prevalence incidence of bradycardia was 2.6% (n = 10 studies; 14/387 patients; 95% CI, 0.3-7.3; I = 75%), the pooled incidence of hypotension was 6.1% (n = 8 studies; 19/304 patients; 95% CI, 0.8-15.9; I = 84%). Three studies (9%) reported side effects' onset time which in all cases was within 12 hours of the infusion starting.

CONCLUSIONS

High-quality data on dexmedetomidine use for prolonged sedation and a consensus on correct dosing and weaning protocols in children are currently missing. Infusion of dexmedetomidine can be considered relatively safe in pediatrics even when longer than 24 hours.

Mechanisms of Dexmedetomidine in Neuropathic Pain

Dexmedetomidin is a new-generation, highly selective α2 adrenergic receptor agonist with a large number of advantages, including its sedative and analgesic properties, its ability to inhibit sympathetic nerves, its reduced anesthetic dosage, its hemodynamic stability, its mild respiratory depression abilities, and its ability to improve postoperative recognition. Its safety and effectiveness, as well as its ability to provide a certain degree of comfort to patients, make it a useful anesthetic adjuvant for a wide range of clinical applications. For example, dexmedetomidine is commonly used in patients undergoing general anesthesia, and it also exerts sedative effects during tracheal intubation or mechanical ventilation in intensive care unit patients. In recent years, with the deepening of clinical research on dexmedetomidine, the drug is still applied in the treatment of spastic pain, myofascial pain, neuropathic pain, complex pain syndrome, and chronic headache, as well as for multimodal analgesia. However, we must note that the appropriateness of patient and dose selection should be given attention when using this drug; furthermore, patients should be observed for adverse reactions such as hypotension and bradycardia. Therefore, the safety and effectiveness of this drug for long-term use remain to be studied. In addition, basic experimental studies have also found that dexmedetomidine can protect important organs, such as the brain, heart, kidney, liver, and lung, through various mechanisms, such as antisympathetic effects, the inhibition of apoptosis and oxidative stress, and a reduction in the inflammatory response. Moreover, the neuroprotective properties of dexmedetomidine have received the most attention from scholars. Hence, in this review, we mainly focus on the characteristics and clinical applications of dexmedetomidine, especially the role of dexmedetomidine in the nervous system and the use of dexmedetomidine in the relief of neuropathic pain.

Clonidine for pain in non-ventilated infants

BACKGROUND

Critically ill newborn infants undergo a variety of painful procedures or experience a variety of painful conditions during their early life in the neonatal unit. In the critically ill paediatric and neonatal population, clonidine is prescribed as an adjunct to opioids or benzodiazepines aiming to reduce the doses of these drugs that are required for analgesia or sedation, or to facilitate weaning from mechanical ventilation. It has been shown that clonidine premedication might have a positive effect on postoperative pain in children.

OBJECTIVES

To assess the benefit and harms of clonidine for the prevention or treatment of procedural pain; postoperative pain; or pain associated with clinical conditions in non-ventilated neonates.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the CENTRAL, MEDLINE via PubMed, Embase, and CINAHL to December 2018. We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials. We ran an updated search from 1 January 2018 to 11 March 2020 in CENTRAL via CRS Web, MEDLINE via Ovid, and CINAHL via EBSCOhost.

SELECTION CRITERIA

Randomised controlled trials, quasi-randomised controlled trials, and cluster trials comparing clonidine to placebo or no treatment, opioids, paracetamol, dexmedetomidine, or non-pharmacological pain-reducing interventions for the management of procedural pain, postoperative pain, and pain associated with clinical conditions in preterm and term newborns.

DATA COLLECTION AND ANALYSIS

Two review authors independently planned to extract data (e.g. number of participants, birth weight, gestational age, modality of administration, and dose of clonidine) and assess the risk of bias (e.g. adequacy of randomisation, blinding, completeness of follow-up). The primary outcome considered was pain: for procedural pain, the mean values of each analgesia scale assessed during the procedure and at one to two hours after the procedure; for postoperative pain and for pain associated with clinical conditions, the mean values of each analgesia scale assessed at 30 minutes, three hours, and 12 hours after the administration of the intervention. We planned to use the GRADE approach to assess the quality of evidence.

MAIN RESULTS

Our search strategy yielded 3383 references. Two review authors independently assessed all references for inclusion. We did not find any completed studies for inclusion. We excluded three trials where clonidine was administered for spinal anaesthesia.

AUTHORS' CONCLUSIONS

We did not find any studies that met our inclusion criteria and hence there is no evidence to recommend or refute the use of clonidine for the prevention or treatment of procedural or postoperative pain, or pain associated with clinical conditions in neonates.

Role of JNK Signaling Pathway in Dexmedetomidine Post-Conditioning-Induced Reduction of the Inflammatory Response and Autophagy Effect of Focal Cerebral Ischemia Reperfusion Injury in Rats

To investigate the effect of dexmedetomidine post-conditioning on the inflammatory response and autophagy effect of focal cerebral ischemia reperfusion injury in rats, and further to study its potential mechanisms. Water maze was conducted to evaluate spatial learning and memory ability of middle cerebral artery occlusion (MCAO) rats. TTC staining was used to observe the area of cerebral infarction. The expressions of inflammatory factors in serum were detected by ELISA. TUNEL assay, HE staining, and transmission electron microscopy were used to detect the apoptosis of neurons, neuro-cytopathic changes, and the formation of auto-phagosome in hippocampus CA1 region, respectively. The mRNA and protein expression of Beclin-1, Caspase-3, and light chain 3 (LC3) were detected by qRT-PCR and Western blot. Moreover, the activity of C-Jun N-terminal kinase (JNK) pathway was detected by Western blot. The escape latency (EL); cerebral infarction area ratio; positive apoptosis; neuron pathological changes; auto-phagosome numbers; inflammatory factor contents; mRNA and protein expressions of Beclin-1, Caspase-3 and LC3II/I; and the phosphorylation level of JNK were decreased, while the times across platform and the times stayed in the quadrant of the original platform were increased after dexmedetomidine treatment. However, the protective effect of dexmedetomidine on brain injury in MCAO rats was reversed by JNK pathway activator. Dexmedetomidine post-conditioning could improve learning and memory dysfunction caused by MCAO in rats and reduce the inflammatory response and autophagy effect. The mechanism may be related to inhibition of JNK pathway activation.

Intravenous Fentanyl 4 μg per kg Administered before Scalp Pin Application is Inferior to Scalp Block in Preventing Hemodynamic Changes

Background:

Application of scalp pins for craniotomy surgeries is a noxious stimulus, causing tachycardia and hypertension, resulting in increased cerebral blood flow and elevated intracranial pressure, hence measures to attenuate this will have beneficial role.

Aims:

The aim is to compare the effectiveness of scalp block (SB) to 4 μg.kg^-1 intravenous (i.v) fentanyl in attenuating hemodynamic response to scalp pin application in patients who underwent elective craniotomy under general anesthesia.

Settings and Design:

The study design involves prospective, randomized study conducted at Tertiary care center/hospital.

Subjects and Methods:

Forty-four American Society of Anesthesiologists physical status Classes l and II patients were randomly allocated into the following groups: Group-SB (n = 22) received SB using 0.25% injection bupivacaine and Group-F (n = 22) received 1 μg.kg^-1 i.v fentanyl. Patient's heart rate (HR) and mean arterial pressure (MAP) were recorded from the application of pins till 60 min and rescue analgesic/anesthetic agents and their dosage were noted. Statistical analysis was performed comparing HR and MAP changes to application of scalp pins.

Statistical Analysis:

Software developed by the Centre for Disease Control, Atlanta, namely Epidemiological Information Package 2010 was used to derive statistical variables.

Results:

Patients were comparable in age, gender, hypertension as comorbidity, baseline HR, and MAP. Significant rise in HR was noted in Group-F till 20^th min compared to Group-SB. MAP was high from application of pins till 60^th min in Group-F compared to Group-SB. Requirement of rescue analgesics/anesthetics was high in Group-F compared to Group-SB.

Conclusion:

SB effectively attenuates hemodynamic response to application of scalp pins in patients undergoing elective craniotomy and reduces requirement of rescue analgesic and/or anesthetics.

Role of dexmedetomidine infusion after coronary artery bypass grafting

Background

Postoperative pain has negative consequences on patients' outcomes after cardiac surgery. Routine management with opioid and or non-steroidal anti-inflammatory medications has several disadvantages. Dexmedetomidine is a selective α2 agonist used for sedation and analgesia. The use of dexmedetomidine for postoperative pain management and decreasing delirium and agitation in cardiac surgery patients is a matter of debate. Our objective was to determine the role of an early administration of dexmedetomidine in decreasing opioid use post-cardiac surgery and its effects on the quality of postoperative recovery.

Results

Medical records of 120 patients admitted to the cardiac surgery intensive care unit (CSICU) after coronary artery bypass grafting (CABG) in two cardiac centers between December 2015 and December 2016 were reviewed. Patients were divided into two groups. Group A included 55 patients who received dexmedetomidine in a dose of 0.2-0.4 mcg/kg/h on admission to CSICU, and group B included 65 patients who did not receive dexmedetomidine. The primary outcome was the pain score immediately after extubation, and the secondary outcomes included post-extubation sedation and pain scores for 12 h.There were significant decrease of the pain scores in dexmedetomidine group that continues through the 3rd, 6th, 8th, and 12th hour readings after surgery with mean modified Ramsay scores 0.1 ± 0.0, 0.89 ± 2.05, 0.35 ± 0.1, and 0.12 ± 1.1 respectively compared to 0.46 ± 1.15, 3.46 ± 2.93, 0.98 ± 1.90, and 0.12 ± 1.1 in group B (p < 0.001), significant decrease in cumulative morphine received (p < 0.001, OR = 909, 95% CI 0.05-0.19), favorable reduction in heart rate in dexmedetomidine group (80 ± 1.9 b/min) compared to 96 ± 8.8 b/min in the other group (p = 0.017), and smoother recovery from general anesthesia.

Conclusion

Administration of dexmedetomidine in the early postoperative period can be safe. It may reduce the use of opioids, has sedative, analgesic, and sympatholytic effects that could play a useful role during the management of coronary artery bypass patients, and may improve postoperative recovery.

Comparison of Intraoperative Sedation With Dexmedetomidine Versus Propofol on Acute Postoperative Pain in Total Knee Arthroplasty Under Spinal Anesthesia: A Randomized Trial

BACKGROUND

In patients undergoing total knee arthroplasty under spinal anesthesia, we compared the postoperative analgesic effect of intraoperative sedation with dexmedetomidine versus propofol. We hypothesized that sedation with dexmedetomidine would result in lower postoperative opioid analgesic consumption than with propofol.

METHODS

Forty-eight patients were enrolled and randomly assigned to either a dexmedetomidine group (n = 24), which received a loading dose of 1 μg/kg dexmedetomidine over 10 minutes, followed by a continuous infusion of 0.1-0.5 μg·kg·hour, or a propofol group (n = 24), which received a continuous infusion of propofol via a target-controlled infusion to maintain the effect-site concentration within a range of 0.5-2.0 μg/mL. The drug infusion rate was determined according to the sedation level, targeting a modified observer's assessment of alertness/sedation score of 3 or 4. The cumulative amounts of fentanyl administered via intravenous patient-controlled analgesia were recorded at 24 and 48 hours postoperatively (primary outcome). The postoperative numerical rating scale for pain was assessed at 6, 12, 24, and 48 hours (secondary outcome). The postoperative use of additional rescue analgesic (ketoprofen) and antiemetic drugs was also compared between the 2 groups at 24 and 48 hours.

RESULTS

Dexmedetomidine significantly reduced postoperative fentanyl consumption (median [interquartile range]) during 0-24 hours (45 [30-71] vs 150 [49-248] μg, P = .004; median difference = -105 μg [99.98% CI, 210-7.5]), 24-48 hours (90 [45-143] vs 188 [75-266] μg, P = .005; median difference = -98 μg [99.98% CI, 195-45]), and 0-48 hours (135 [68-195] vs 360 [146-480] μg, P = .003; median difference = -225 μg [99.98% CI, 405-7.5]). The numerical rating scale (median [interquartile range]) was lower at 6 hours (1 [0-2] vs 2 [1-3], P = .003), 12 hours (1 [1-2] vs 3 [2-3], P < .001), 24 hours (1 [1-2] vs 3 [2-3], P < .001), and 48 hours (2 [2-3] vs 3 [3-4], P < .001) after surgery in the dexmedetomidine group compared to the propofol group. No significant intergroup differences were observed in the amount of rescue analgesics and antiemetics at 24 hours (P = .155 and P = .482) and 48 hours (P = .082 and P = .153) after surgery.

CONCLUSIONS

Intraoperative dexmedetomidine sedation was associated with a small but clinically important reduction in postoperative opioid use after total knee arthroplasty.

Randomized comparison between dexmedetomidine–remifentanil and midazolam–fentanyl for deep sedation during catheter ablation of atrial fibrillation

Background and objectives

The efficacy of dexmedetomidine for radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) has not been well established. We evaluated the efficacy and safety of sedation using dexmedetomidine with remifentanil compared to conventional sedative agents during RFCA for AF.

Subjects and methods

A total of 240 patients undergoing RFCA for AF were randomized to either the dexmedetomidine (DEX) group (continuous infusion of dexmedetomidine and remifentanil) or the midazolam (MID) group (intermittent injections of midazolam and fentanyl) according to sedative agents. Non-invasive positive pressure ventilation was applied to all patients during the procedure. The primary outcome was patient movement during the procedure resulting in a 3D mapping system discordance, and the secondary outcome was adverse events including respiratory or hemodynamic compromise.

Results

During AF ablation, the incidence of the primary outcome was significantly reduced for the DEX group (18.2% vs. 39.5% in the DEX and the MID groups, respectively, p < 0.001). The frequency of a desaturation event (oxygen saturation < 90%) did not significantly differ between the two groups (6.6% vs. 1.7%, p = 0.056). However, the incidences of hypotension not owing to cardiac tamponade (systolic blood pressure < 80 mmHg, 19.8% vs. 8.4%, p = 0.011) and bradycardia (HR < 50 beats/min: 39.7% vs. 21.8%, p = 0.003) were higher in the DEX group. All efficacy and safety results were consistent within the predefined subgroups.

Conclusion

The combined use of dexmedetomidine and remifentanil provides higher stability sedation during AF ablation, but can lead to more frequent hemodynamic compromise compared to midazolam and fentanyl.

Topical anesthetic analgesic therapy using the combination of ropivacaine and dexmedetomidine: hyaluronic acid modified long-acting nanostructured lipid carriers containing a skin penetration enhancer

Purpose

Hyaluronic acid-poly(ethylene glycol)-distearoyl phosphoethanolamine (HA-PEG-DSPE) modified and tocopheryl polyethylene glycol 1000 succinate (TPGS) contained nanostructured lipid carriers (NLCs) were prepared loading ropivacaine and dexmedetomidine to improve the topical anesthetic analgesic anesthesia efficiency.

Methods

NLCs were prepared by the solvent diffusion method. The average particle size, zeta potential, release behavior, and cytotoxicity of the NLCs were tested. Ex vivo skin permeation was studied using a Franz diffusion cell mounted with depilated rat skin. Local anesthesia antinociceptive efficiency was evaluated by rat tail flick latency study in vivo.

Results

NLCs have sizes of about 100 nm, with negative zeta potentials. All the NLCs formulations were found to be significantly less cytotoxic than free drugs at equivalent concentrations. The cumulative amount of drugs penetrated through rat skin from NLCs was 2.0–4.7 folds higher than that of the drugs solution. The in vivo anesthesia antinociception study displayed that NLCs showed stronger and longer anesthesia antinociceptive effect when compared with single drugs loaded NLCs and drugs solution even at a lower dosage of drugs.

Conclusion

The results demonstrated that the HA modified, TPGS contained, dual drugs loaded NLCs could perform a synergistic effect and may reduce the amount of drugs, which can lower the toxicity of the system and at the meanwhile, increase the anesthesia antinociceptive efficiency.

Comparison of anesthetic effects of dexmedetomidine and tramadol, respectively, combined with propofol in percutaneous microwave coagulation therapy for hepatocellular carcinoma

Anesthetic effects and safety of dexmedetomidine and tramadol, respectively, combined with propofol in ultrasound-guided percutaneous microwave coagulation therapy (PMCT) for hepatocellular carcinoma (HCC) were compared. One hundred and seventy-six patients with HCC, treated by ultrasound-guided PMCT in The Affiliated Hospital of Qingdao University from January 2014 to December 2016, were retrospectively analyzed and divided into two groups: dexmedetomidine group (anesthetized with dexmedetomidine combined with propofol, n=91) and tramadol group (anesthetized with tramadol combined with propofol, n=85). Changes in heart rate (HR), mean arterial pressure (MAP), and oxygen saturation (SpO₂) were recorded before oxygen inhalation (T1), intraoperationally (T2), and at 30 min postoperatively (T3), and the recovery time (recorded from the moment the use of anesthetic drugs stopped), hospital stay, visual analogue scale (VAS) score at 48 h after surgery, as well as the adverse reactions in the perioperative period were compared between the two groups. HR and SpO₂ in the dexmedetomidine group at T2 and T3 were significantly lower than those in the tramadol group (P<0.05). HR and SpO₂ at T2 were significantly lower than those at T1 and T3, and HR at T3 was lower than that at T1 (P<0.05). MAP in the dexmedetomidine group at T2 was significantly lower than that in the tramadol group (t=3.836, P<0.001). MAP at T2 was significantly lower than those at T1 and T3, and MAP at T3 was lower than that at T1 (P<0.05). The number of patients with shivering in the dexmedetomidine group was significantly higher than that in the tramadol group (P<0.05). Both tramadol and dexmedetomidine, respectively combined with propofol in PMCT for HCC surgery can achieve satisfactory anesthetic effects. However, tramadol combined with propofol is more effective in stabilizing the vital signs with less side-effects, and is more suitable for PMCT in patients with HCC than dexmedetomidine combined with propofol, which is worth popularizing and applying in clinic.

Dexmedetomidine inhibits the lipopolysaccharide-stimulated inflammatory response in microglia through the pathway involving TLR4 and NF-κB

To investigate the effects of dexmedetomidine (DEX) on lipopolysaccharide (LPS)-induced neuroinflammation in BV2 microglia. BV2 microglial cells were treated with various concentrations of DEX (0, 1, 10, and 100 ng/mL) for 1 hour, and then incubated in the presence or absence of 0.1 μg/mL LPS for 24 hours. Cell viability was assessed by Cell Counting Kit-8 assays. The expression levels of IL-1β, IL-6, and TNF-α were determined using enzyme-linked immunosorbent assay (ELISA). The expressions of TLR4 and NF-кB were detected by western blotting. Moreover, BV2 microglial cells were transfected with small interfering RNA (siRNA) specific for TLR4 (si-TLR4 group) or negative control siRNA (si-NC group) for 24 hours, followed by exposing to 0.1 μg/mL LPS for 24 hours. TLR4, IL-1β, IL-6, and TNF-α expressions were detected by quantitative real-time reverse transcription-polymerase chain reaction (RT-qPCR). There were no significant differences in cell viability with the different treatments. Compared with the control group, LPS markedly increased the release of IL-6, TNF-α, IL-1β, TLR4, and NF-κB, but these increases were significantly attenuated by pretreatment with 10 or 100 ng/mL DEX in a dose-dependent relationship, but not with 1 ng/mL DEX. Gene expression levels of IL-1β, IL-6, and TNF-α were obviously upregulated in si-NC group and si-TLR4 group when cells were exposed to 0.1 μg/mL LPS for 24 hours. Meanwhile, si-TLR4 group had significantly lower IL-1β, IL-6, and TNF-α expressions than si-NC group. The anti-inflammatory effects of DEX on LPS-induced BV2 microglia may be mediated through pathway involving TLR4 and NF-κB.

Dexmedetomidine to facilitate non-invasive ventilation after blunt chest trauma: A randomised, double-blind, crossover, placebo-controlled pilot study

BACKGROUND

Although non-invasive ventilation (NIV) is recommended in patients with chest trauma, this procedure may expose to discomfort and even failure due to agitation or excessive pain. We tested the impact of dexmedetomidine on the duration of the first session of NIV.

METHODS

This randomised, crossover study enrolled 19 patients with blunt chest trauma who needed NIV. During one cycle comprising two NIV sessions, patients received in a random order an intravenous infusion of dexmedetomidine (0.7mcg/kg/h) and placebo (saline solution) that was initiated 60min prior to NIV. Dexmedetomidine (or placebo) was titrated to maintain a Richmond Agitation Sedation Scale (RASS) score between 0 and -3. A 6-h washout period was observed between NIV sessions. The reproducibility of the drug-related effects was tested during a second cycle of two NIV sessions.

RESULTS

During the first cycle, dexmedetomidine prolonged the duration of NIV compared to placebo: 280min (118-450) (median, 25-75th quartiles) versus 120min (68-287) respectively, corresponding to a median increased duration of 96min (12-180) (P=0.03). Dexmedetomidine was associated with a lower score for RASS: -0.8 (-1.0;0.0) versus 0.0 (-0.5;0.0) (P<0.01), and reduced respiratory discomfort according to the 10cm visual similar scale: 0.6cm (0.0-3.0) versus 2.2cm (0.0-5.3) (P=0.05). Pain scores, morphine consumption, and blood gas measurements were comparable between groups. No difference in the duration of non-invasive ventilation was found during the second cycle.

CONCLUSIONS

In this pilot trial, dexmedetomidine could facilitate the acceptance of the first session of non-invasive ventilation for patients with chest trauma.

Safety and sedative effect of intranasal dexmedetomidine in mandibular third molar surgery: a systematic review and meta-analysis

Objective

The focus of this meta-analysis was to assess the sedative effect and safety of intranasal dexmedetomidine (Dex) in mandibular third molar surgery.

Methods

The PubMed/Medline, Web of Science, Cochrane Library, and China National Knowledge Infrastructure databases were searched for studies published until May 1, 2018. Eligible studies were restricted to randomized controlled trials (RCTs) and controlled clinical trials. The evaluation indicators mainly included the bispectral index, observer assessment of alertness/sedation scale, systolic blood pressure, and heart rate. Data for each period in the Dex and control groups were pooled to evaluate its sedative effect and safety.

Results

Five RCTs met the inclusion criteria. This study included 363 patients: 158 patients received intranasal inhalation of Dex before surgery, and 158 patients were negative controls. The pooled results showed a good sedative effect during tooth extraction when intranasal inhalation of Dex was performed 30 minutes before third molar extraction (assessment of alertness/sedation, Dex vs control SMD −1.20, 95% CI −1.73 to −0.67, I²=0, P=0.95; bispectral index, Dex vs control SMD −11.68, 95% CI −19.49 to −3.87, I²=89%; P=0.0001), and parameters returned to normal within 90 minutes after inhalation. During the operation, blood pressure and heart rate decreased to some extent, but the decreases did not exceed 20% of the baseline, and all patients returned to normal conditions within 90 minutes after inhalation.

Conclusion

Intranasal inhalation of Dex 30 minutes before third molar extraction can provide a good sedative effect, and large-sample multicenter RCTs are needed to evaluate the analgesic effect of Dex.

Determination of blood dexmedetomidine in dried blood spots by LC-MS/MS to screen therapeutic levels in paediatric patients

Dexmedetomidine is an imidazole derivative, with high affinity for α2 adrenergic receptors, used for sedation, analgesia and adjuvant anaesthesia. In this study, an analytical method for the quantification of dexmedetomidine in dried blood spots was developed, validated and applied. The drug was extracted from dried blood spot by liquid extraction; the separation was carried out by ultra high-resolution liquid chromatography in reverse phase coupled to tandem mass spectrometry method. An X Select cyano 5 μm HSS column (2.1 X 150 mm, Waters) and a mobile phase composed of 0.1% formic acid: acetonitrile [50:50 v/v], were used. The test was linear over the concentration range of 50 to 2000 pg/mL. The coefficients of variation for the intra and interday trials were less than 15%. The drug was stable under the conditions tested. The method was successfully applied for the quantification of 6 patients, aged 0 to 2 years, with classification ASA I, who underwent ambulatory surgeries, receiving a dose of 1 μg/Kg dexmedetomidine IV. The drug concentrations in the different sampling times were in the range of 76 to 868 pg/mL.

Postoperative cognitive dysfunction in the aged: the collision of neuroinflammaging with perioperative neuroinflammation

The aging population is burgeoning globally and this trend presents great challenges to the current healthcare system as the growing number of aged individuals receives procedures of surgery and anesthesia. Postoperative cognitive dysfunction (POCD) is a severe postoperative neurological sequela. Advanced age is considered as an independent risk factor of POCD. Mounting evidence have shown that neuroinflammation plays an essential role in POCD. However, it remains debatable why this complication occurs highly in the aged individuals. As known, aging itself is the major common high-risk factor for age-associated disorders including diabetes, cardiovascular disease, cancer, and neurodegenerative diseases. Chronic low-grade neuroinflammation (dubbed neuroinflammaging in the present paper) is a hallmark alternation and contributes to age-related cognitive decline in the normal aging. Interestingly, several lines of findings show that the neuroinflammatory pathogenesis of POCD is age-dependent. It suggests that age-related changes, especially the neuroinflammaging, are possibly associated with the postoperative cognitive impairment. Understanding the role of neuroinflammaging in POCD is crucial to elucidate the mechanism of POCD and develop strategies to prevent or treat POCD. Here the focus of this review is on the potential role of neuroinflammaging in the mechanism of POCD. Lastly, we briefly review promising interventions for this neurological sequela.

The effect of dexmedetomidine on the perioperative hemodynamics and postoperative cognitive function of elderly patients with hypertension: Study protocol for a randomized controlled trial

INTRODUCTION

Cognitive dysfunction after surgery, a common clinical manifestation of postoperative psychonosema. It usually occurs after heart surgery, hip replacement, mandibular fractures, and other major operations. Dexmedetomidine can exert sedative, analgesic, anxiolytic effect, inhibits the sympathetic activity, maintains hemodynamic balance, helps reduce the amount of anesthetic agents, and relatively slightly depresses respiration. Preoperative administration of dexmedetomidine for sedation has been reported to reduce the incidence of acute postoperative delirium. But currently there is no study on the effect of dexmedetomidine on the postoperative cognitive function of elderly patients with essential hypertension.

METHODS/DESIGN

This study is a prospective, single-center, double-blind controlled clinical trial. Elderly patients aged between 60 and 80 years old, diagnosed with primary hypertension for 1 year or longer will be included, and randomized into 2 groups. Patients in observational group will be given a loading dose of dexmedetomidine at 0.8 μg/kg, pumped for over 10 minutes. Although patients in control group will be pumped of the same volume of normal saline within 10 minutes, before the induction of anesthesia. Minimental state examination and levels of interleukin-6, tumor necrosis factor alpha, and C-reactive protein will be set as primary endpoints. Baseline characteristics of patients will be summarized by groups and compared using Chi-square or Fisher exact tests for categorical variables and 2-sample t tests or Wilcoxon rank sum test for the continuous variables. Repeated measurement analysis of covariance model will also be used for the comparison of endpoints between 2 groups.

CONCLUSION

The present study is designed to investigate the effect of the application of dexmedetomidine on postoperative myocardial injury and postoperative cognitive dysfunction, also to explore the association between inflammatory factors and postoperative cognitive function. With this study, we are expecting to find out an appropriate anesthesia method for elderly people with hypertension to alleviate the postoperative adverse effects caused by medical treatments.

TRIALS REGISTRATION

This study was registered on Chinese Clinical Trial Registry (http://www.chictr.org.cn/) with the ID ChiCTR-IPR-16009156.