Dexmedetomidine: an updated review

Effectiveness of dexmedetomidine on patient-centred outcomes in surgical patients: a systematic review and Bayesian meta-analysis

BACKGROUND

Dexmedetomidine is increasingly used for surgical patients requiring general anaesthesia. However, its effectiveness on patient-centred outcomes remains uncertain. Our main objective was to evaluate the patient-centred effectiveness of intraoperative dexmedetomidine for adult patients requiring surgery under general anaesthesia.

METHODS

We conducted a systematic search of MEDLINE, Embase, CENTRAL, Web of Science, and CINAHL from inception to October 2023. Randomised controlled trials (RCTs) comparing intraoperative use of dexmedetomidine with placebo, opioid, or usual care in adult patients requiring surgery under general anaesthesia were included. Study selection, data extraction, and risk of bias assessment were performed by two reviewers independently. We synthesised data using a random-effects Bayesian regression framework to derive effect estimates and the probability of a clinically important effect. For continuous outcomes, we pooled instruments with similar constructs using standardised mean differences (SMDs) and converted SMDs and credible intervals (CrIs) to their original scale when appropriate. We assessed the certainty of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. Our primary outcome was quality of recovery after surgery. To guide interpretation on the original scale, the Quality of Recovery-15 (QoR-15) instrument was used (range 0-150 points, minimally important difference [MID] of 6 points).

RESULTS

We identified 49,069 citations, from which 44 RCTs involving 5904 participants were eligible. Intraoperative dexmedetomidine administration was associated with improvement in postoperative QoR-15 (mean difference 9, 95% CrI 4-14, n=21 RCTs, moderate certainty of evidence). We found 99% probability of any benefit and 88% probability of achieving the MID. There was a reduction in chronic pain incidence (odds ratio [OR] 0.42, 95% CrI 0.19-0.79, n=7 RCTs, low certainty of evidence). There was also increased risk of clinically significant hypotension (OR 1.98, 95% CrI 0.84-3.92, posterior probability of harm 94%, n=8 RCTs) and clinically significant bradycardia (OR 1.74, 95% CrI 0.93-3.34, posterior probability of harm 95%, n=10 RCTs), with very low certainty of evidence for both. There was limited evidence to inform other secondary patient-centred outcomes.

CONCLUSIONS

Compared with placebo or standard of care, intraoperative dexmedetomidine likely results in meaningful improvement in the quality of recovery and chronic pain after surgery. However, it might increase clinically important bradycardia and hypotension.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO (CRD42023439896).

Dexmedetomidine withdrawal syndrome and opioid sensitivity

This case report describes the use of dexmedetomidine for refractory cancer pain management in a patient with significant pelvic disease due to metastatic urothelial cancer. Specifically, the management of increased opioid sensitivity secondary to dexmedetomidine is discussed. Further, the phenomenon of dexmedetomidine withdrawal syndrome and our management of this is addressed.

Radioprotective effects of α2-adrenergic receptor agonist dexmedetomidine on X-ray irradiation-induced pancreatic islet cell damage

Comprehensive epidemiological analyses conducted in the last 30 years have revealed a link between radiation and DM. We aimed to determine the effects of dexmedetomidine pretreatment on radiation-induced pancreatic islet cell damage. Twenty-four rats were divided into three groups: group 1 (control group), group 2 (only X-ray irradiation group), and group 3 (X-ray irradiation + dexmedetomidine). We observed necrotic cells with vacuoles accompanying loss of cytoplasm in the islets of Langerhans, extensive edematous areas, and vascular congestions in group 2. In group 3, we observed a decrease in necrotic cells in the islets of Langerhans, and edematous areas and vascular congestion was also reduced. We determined a decrease in β-cells, α-cells, and D-cells in the islets of Langerhans in group 2 compared to the control group. In group 3, β-cells, α-cells, and D-cells were elevated compared to group 2. Ionizing radiation may induce DM. Dexmedetomidine appears to exert a radioprotective effect.

The effects of subtenon and intravenous dexmedetomidine on patients undergoing cataract surgery: A comparative randomized controlled double-blind study

Background and Aims

This prospective randomized study designed to evaluate the efficacy of dexmedetomidine either added to LA mixture or administered IV during subtenon block for cataract surgery.

Material and Methods

75 patients, undergoing cataract surgery with subtenon anesthesia, were assigned randomly into three equal groups, Group I received subtenon bupivacaine 0.5% (1 ml) + lidocaine 2% (1 ml) + saline 0.9% (0.5 ml) and IV infusion of normal saline. Group II received subtenon bupivacaine 0.5% (1 ml) + lidocaine 2% (1 ml) + 0.5 μg/kg dexmedetomidine (0.5 ml) and IV infusion of normal saline. Group III received subtenon bupivacaine 0.5% (1 ml) + lidocaine 2% (1 ml) + saline 0.9% (0.5 μl) and IV infusion of 0.5 mg/kg dexmedetomidine over 10 min. before subtenon block. We recorded onset and duration of sensory and motor block, pain during subtenon injection, intraoperative hemodynamics, intraocular pressure, sedation and postoperative pain score.

Results

There was a significant decrease in the onset of action and an increase in the duration of sensory block in Group II. Pain during subtenon injection was significantly less in group III. Sedation Score was higher in Group III, while heart rate showed a significant reduction in the same group. The VAS was significantly decreased in group II. After the end of surgery, the intraocular pressure was significantly decreased in Groups II and III.

Conclusion

Subtenon dexmedetomidine shortens onset time, prolongs sensory block durations and significantly decreases the postoperative pain score with hemodynamic stability, while, IV dexmedetomidine substantially reduces pain during subtenon block and produces intra-operative sedation.

The Effects of Dexmedetomidine on Abdominal Aortic Occlusion-Induced Ovarian Injury via Oxidative Stress and Apoptosis

Ischemia/reperfusion (I/R) induced ovarian damage is caused by various diseases such as ovarian torsion, ovarian transplantation, cardiovascular surgery, sepsis, or intra-abdominal surgery. I/R-related oxidative damage can impair ovarian functions, from oocyte maturation to fertilization. This study investigated the effects of dexmedetomidine (DEX), which has been shown to exhibit antiapoptotic, anti-inflammatory, and antioxidant effects, on ovarian I/R injury. We designed four study groups: group 1 (n = 6): control group; group 2 (n = 6): only DEX group; group 3 (n = 6): I/R group; group 4 (n = 6): I/R + DEX group. Then, ovarian samples were taken and examined histologically and immunohistochemically, and tissue malondialdehyde (MDA) and glutathione (GSH) levels were measured. In the I/R group MDA levels, caspase-3, NF-κB/p65, 8-OHdG positivity, and follicular degeneration, edema, and inflammation were increased compared to the control group (p = 0.000). In addition, GSH levels were significantly decreased in the I/R group compared to the control group (p = 0.000). On the other hand, in the I/R + DEX treatment group MDA levels, caspase-3, NF-κB/p65, 8-OHdG positivity, follicular degeneration, edema, and inflammation findings were decreased than in the I/R group (p = 0.000, p = 0.005, p = 0.005, p = 0.001, p = 0.005, respectively). However, GSH levels increased significantly in the I/R + DEX treatment group compared to the I/R group (p = 0.000). DEX protects against ovarian I/R injury through antioxidation and by suppressing inflammation and apoptosis.

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

OBJECTIVES

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

DATA SOURCES

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

DATA EXTRACTION

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

DATA SYNTHESIS

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

CONCLUSIONS

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

Sedation for adult ICU patients: A narrative review including a retrospective study of our own data

The optimization of patients' treatment in the intensive care unit (ICU) needs a lot of information and literature analysis. Many changes have been made in the last years to help evaluate sedated patients by scores to help take care of them. Patients were completely sedated and had continuous intravenous analgesia and neuromuscular blockades. These three drug classes were the main drugs used for intubated patients in the ICU. During these last 20 years, ICU management went from fully sedated to awake, calm, and nonagitated patients, using less sedatives and choosing other drugs to decrease the risks of delirium during or after the ICU stay. Thus, the usefulness of these three drug classes has been challenged. The analgesic drugs used were primarily opioids but the use of other drugs instead is increasing to lessen or wean the use of opioids. In severe acute respiratory distress syndrome patients, neuromuscular blocking agents have been used frequently to block spontaneous respiration for 48 hours or more; however, this has recently been abolished. Optimizing a patient's comfort during hemodynamic or respiratory extracorporeal support is essential to reduce toxicity and secondary complications.

Global trends in research related to emergence delirium, 2012–2021: A bibliometric analysis

Introduction

Emergence delirium is a kind of mental disorder during the early awakening period after general anesthesia, which is manifested as the combination of perceptual disturbance and psychomotor agitation. It is an independent risk factor for postoperative delirium and even long-term postoperative cognitive decline, which often affects the postoperative outcome and deserves the attention of clinical anesthesiologists. There are many studies on emergence delirium, but the quantity and quality of these studies are unclear. Therefore, we conducted a bibliometric analysis of studies on emergence delirium between January 2012 and December 2021. Through the analysis of relevant literature, the research hotspots and trends of emergence delirium are understood, which can provide a reference for future research.

Methods

We searched the Web of Science Core Collection (WoSCC) for original articles and reviews related to emergence delirium published between 2012 and 2021, and collected a variety of bibliographic elements, including annual publications, authors, countries/regions, institutions, journals, and keywords. Three different science-based tools (CiteSpace, VOSviewer and Bibliometrix) were used for this comprehensive analysis.

Results

From January 2012 to December 2021, a total of 912 emergence delirium (ED) related literature were published, including 766 original research articles and 146 review articles. The number of publications has increased every year except 2016. The United States published 203 articles, ranking first with China, followed by South Korea (95 articles). The United States is also the country with the most citations (4,508), and Yonsei Univ is the most productive institution. The most published journal was PEDIATRIC ANESTHESIA, with the highest h and g index. LEE JH is the most influential author in this field.

Discussion

“Children, emergence agitation, delirium, dexmedetomidine” are the hot topics in this field in recent years. The bibliometric analysis in this field will provide the future direction for the study of emergence delirium for clinicians.

Efficacy of intraoperative sedation combined with preemptive analgesia for single-level kyphoplasty under local anesthesia: A randomized clinical trial

BACKGROUND

Kyphoplasty is widely used for Osteoporotic Vertebral Compression Fracture (OVCF) under general or local anesthesia, more attention was paid to its post-operative efficacy. Patients' pain and discomfort control strategies during surgery have not been taken seriously.

OBJECTIVE

This study aimed at assessing the efficacy of preoperative preemptive analgesia combined with intraoperative sedation for pain and tension relief in OVCF patients undergoing kyphoplasty under local anesthesia.

METHODS

We enrolled 128 patients with single-level OVCF who underwent kyphoplasty in our hospital from July 2013 to July 2016. The patients were randomly allocated into three groups: conventional group (i.e., local anesthesia with 0.5% lidocaine (1); n = 42), preemptive group (i.e, (1) + oral 200 mg Celecoxib on the night before surgery with intravenous 40 mg parecoxib sodium an hour before surgery (2); n = 43), and combined group (i.e., (1) + (2) + continuous intravenous 0.5 μg/kg/h dexmedetomidine intraoperatively; n = 43). Hemodynamic variations (heart rate, blood pressure, pulse oxygen saturation (SpO₂)), Pain Visual Analogue Score (VAS), Ramsay score, and adverse events were recorded during perioperative period.

RESULTS

Blood pressure and heart rate were more stable with significantly smaller values in the combined group than in the conventional and preemptive groups both intra- and postoperatively. In contrast, SpO₂ showed no significant difference among the groups throughout the perioperative period. Intraoperative VAS scores revealed significant differences among the groups with the combined group having the smallest values followed by the preemptive group. Similarly, intraoperative Ramsay scores reflected significantly more favorable effects of sedation in the combined than in conventional group. Both VAS and Ramsay scores showed no significant differences among the groups postoperatively, and no differences in complication incidences were noted among the groups as well.

CONCLUSIONS

For kyphoplasty under local anesthesia for single-level OVCF, intraoperative sedation combined with preemptive analgesia worked better in mitigating pain and tension intraoperatively and in preventing hemodynamic changes intra- and post-operatively, as compared to local anesthesia alone or additional preemptive analgesia.

Dexmededomidine in pediatric unilateral internal inguinal ring ligation

BACKGROUND

Safe and effective analgesia strategy remains one of the priorities for pediatric inguinal hernia treatment.

AIM

To explore safety and efficacy of dexmededomidine monotherapy for postoperative analgesia in children who received laparoscopic unilateral internal inguinal ring ligation.

METHODS

This randomized single-center controlled trial included 390 children (aged 1-3 years, ASA grade I-II), randomly divided into a dexmededomidine group (D group), a dexmededomidine + sufentanil group (DS group), and a sufentanil group (S group). The primary endpoint was percentage of children with the Face, Legs, Activity, Cry, and Consolability (FLACC) score ≤ 3 points 2 h after surgery.

RESULTS

The comparisons of the FLACC scores at 2, 4, 6, 8, 12, and 24 h were not significantly different among the three groups (P > 0.05). The sedative effects in the D group were significantly better than those in the S group (P > 0.05), but not significantly different from those in the DS group. The incidence of nausea and vomiting was significantly lower in the D group than in the S group and DS group (P > 0.05).

CONCLUSION

Analgesic effects of dexmededomidine monotherapy are comparable to those of sufentanil alone or in combination with dexmededomidine for children who underwent laparoscopic unilateral internal inguinal ring ligation, with better sedative effects and a lower incidence of adverse events.

Sequential use of midazolam and dexmedetomidine for long-term sedation may reduce weaning time in selected critically ill, mechanically ventilated patients: a randomized controlled study

Background

Current sedatives have different side effects in long-term sedation. The sequential use of midazolam and dexmedetomidine for prolonged sedation may have distinct advantages. We aimed to evaluate the efficacy and safety of the sequential use of midazolam and either dexmedetomidine or propofol, and the use of midazolam alone in selected critically ill, mechanically ventilated patients.

Methods

This single-center, randomized controlled study was conducted in medical and surgical ICUs in a tertiary, academic medical center. Patients enrolled in this study were critically ill, mechanically ventilated adult patients receiving midazolam, with anticipated mechanical ventilation for ≥ 72 h. They passed the spontaneous breathing trial (SBT) safety screen, underwent a 30-min-SBT without indication for extubation and continued to require sedation. Patients were randomized into group M-D (midazolam was switched to dexmedetomidine), group M-P (midazolam was switched to propofol), and group M (sedation with midazolam alone), and sedatives were titrated to achieve the targeted sedation range (RASS − 2 to 0).

Results

Total 252 patients were enrolled. Patients in group M-D had an earlier recovery, faster extubation, and more percentage of time at the target sedation level than those in group M-P and group M (all P < 0.001). They also experienced less weaning time (25.0 h vs. 49.0 h; HR1.47, 95% CI 1.05 to 2.06; P = 0.025), and a lower incidence of delirium (19.5% vs. 43.8%, P = 0.002) than patients in group M. Recovery (P < 0.001), extubation (P < 0.001), and weaning time (P = 0.048) in group M-P were shorter than in group M, while the acquisition cost of sedative drug was more expensive than other groups (both P < 0.001). There was no significant difference in adverse events among these groups (all P > 0.05).

Conclusions

The sequential use of midazolam and dexmedetomidine was an effective and safe sedation strategy for long-term sedation and could provide clinically relevant benefits for selected critically ill, mechanically ventilated patients.

Trial registration

NCT02528513. Registered August 19, 2015.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-03967-5.

Comparison of the Efficacy and Safety of Dexmedetomidine Administered in Two Different Modes Under Procedural Sedation and Analgesia in Plastic Surgery

Background

Dexmedetomidine (DEX), a highly selective α2-adrenergic receptor agonist, is now widely used in procedural sedation and analgesia. This study was designed to observe and compare the efficacy and safety of DEX administered in two different modes.

Methods

In total, 100 patients were randomly divided into two groups to receive intravenous DEX 1 µg/kg over 15 min followed by 0.4–0.7 µg/kg/h infusion or DEX 1 µg/kg over 30 min followed by 0.4–0.7 µg/kg/h infusion. Heart rate (HR), mean arterial pressure (MAP), respiratory rate (RR), bispectral index (BIS), Ramsay Sedation Scores (RSS scores), the lowest respiratory rates (LRR), incidences of respiratory adverse events and frequencies of body movements were recorded. Recovery time, recall of intraoperative events, pain scores in PACU and satisfaction of patients and surgeons were assessed.

Results

The BIS at time points from 5 min after anesthesia to the end of surgery in the intervention group were significantly higher (p < 0.05). The RSS scores at time points from 5 min after anesthesia to immediately after induction with DEX were significantly higher in the intervention group (p < 0.05). The HR at time points from the beginning of surgery to 30 min after local anesthesia, the MAP at time points from 30 min after local anesthesia to the end of surgery, and the RR at time points from 5 min after anesthesia to the end of surgery were significantly higher in the intervention group (p < 0.05). Patients in the intervention group had higher LRR, lower incidences of respiratory adverse events, and shorter recovery time (p < 0.05).

Conclusions

Dexmedetomidine infused with a loading dose over 30 min had less impact on patients’ hemodynamics and respiration and could shorten the recovery time after anesthesia in procedural sedation and analgesia.

Clinical Trial Registration

ClinicalTrials.gov, identifier: ChiCTR1900027958.

A randomized comparison between interscalene block and dexmedetomidine for arthroscopic shoulder surgery

Introduction: Management of intraoperative hemodynamics and postoperative analgesia during arthroscopic shoulder surgeries remains a challenge. Although interscalene brachial plexus block (ISB) is considered ideal for shoulder anesthesia it requires skill and proficiency unlike intravenous (IV) dexmedetomidine. Objective: This randomized trial was performed to observe the efficacy of dexmedetomidine infusion which is less invasive and demands lesser skills than plexus block. Methodology: All patients scheduled for elective arthroscopic shoulder surgery under general anesthesia were assigned either to group DEX, which received an IV dexmedetomidine bolus of 0.5 mcg/kg over 20 minutes, followed by an infusion of 0.5 mcg/kg/hour that was stopped 30 minutes before surgery the end of surgery or to group BLOCK which received ultrasound guided ISB with 20ml of 0.25% bupivacaine. The primary outcome assessed was intraoperative hemodynamics; the secondary outcomes were immediate postoperative pain, operating condition as assessed by the surgeon, recovery time, and patient satisfaction after 24 hours. Blinded investigator and composite scores were used for the assessment. Results: Both groups displayed equivalent scores for intraoperative hemodynamics whereas ISB resulted in a better post-operative analgesia (p < 0.001). Surgeon’s opinion and recovery time were comparable. Overall, the patients had a satisfactory experience with both techniques, according to the quality assessment. Conclusion: IV dexmedetomidine infusion is an effective alternative to ISB for reconstructive shoulder surgeries under general anesthesia.

Sedation with Intranasal Dexmedetomidine in the Pediatric Population for Auditory Brainstem Response Testing: Review of the Existing Literature

Background: Intranasal dexmedetomidine (IN DEX) is a relatively new sedative agent with supporting evidence on its efficacy and safety, which can be used for procedural sedation in children, and could have a major role in auditory brainstem response testing, especially in the case of non-cooperative children. The goal of this systematic review is to assess the role of IN DEX in ABR testing, evaluating the reported protocol, potential, and limits. Methods: We performed a comprehensive search strategy on PubMed, Scopus, and Google Scholar, including studies in English on the pediatric population, without time restrictions. Results: Six articles, published between 2016 and 2021, were included in the systematic review. Sedation effectiveness was high across the studies, except for one study; 3 μg/kg was the dosing most often used. A comparison group was present in three studies, with oral chloral hydrate as the drug of comparison. Adverse effects were rarely reported. Conclusion: This systematic review showed how IN DEX can represent an adequate sedative for children undergoing ABR testing; larger and more rigorous trials are warranted in order to recommend its systematic utilization.

Comparing different doses of dexmedetomidine combined with ropivacaine for ultrasound-guided supraclavicular brachial plexus block in upper limb surgeries - A Prospective randomized controlled trial

Background:

Dexmedetomidine is used as an adjuvant to local anesthetic agents to provide prolonged analgesia in peripheral nerve blocks. This study aimed at determining the optimal dose of dexmedetomidine, which when combined with ropivacaine will produce a superior quality block in terms of extended pain-free period and reduced perioperative analgesic/opioid use, which in turn improves patient satisfaction.

Objective:

The objective of the study is to assess the duration of analgesia with two different doses (25 μg and 50 μg) of dexmedetomidine with ropivacaine in supraclavicular brachial plexus block.

Subjects and Methods:

This prospective randomized controlled study included 50 patients undergoing upper limb surgeries under supraclavicular brachial plexus block randomly divided into two groups. Group D25 received 29 mL of 0.5% ropivacaine +25 μg dexmedetomidine diluted in 1 mL of normal saline (total 30 mL); Group D50 received 29 mL of 0.5% ropivacaine +50 μg dexmedetomidine diluted in 1 mL of normal saline (total 30 mL). Onset and duration of sensorimotor block, duration of analgesia, and time interval for the rescue analgesia and hemodynamic stability were observed.

Results:

The mean onset of motor and sensory block was significantly higher in the D25 group (P = 0.001). The Visual Analog Scale pain scores and rescue analgesia consumption were significantly lower in the D50 group (P = 0.013, 0.001). The duration of analgesia was significantly higher in the D50 group (P = 0.001).

Conclusion:

Dexmedetomidine 50 μg is an effective adjuvant dose to ropivacaine with insignificant hemodynamic changes with better duration of analgesia and lesser pain scores.

Comparison of Intra and Post-operative Sedation efficacy of Dexmedetomidine-Midazolam and Dexmedetomidine-Propofol for Major Abdominal Surgery

BACKGROUND

The effectiveness and side effects of dexmedetomidine (DEX) in combination with midazolam and propofol have not been comparatively studied in a single clinical trial as sedative agents to general anesthesia before.

OBJECTIVE

The objective of this study is to compare intra and post-operative sedation between DEX-Midazolam and DEX-Propofol in patients who underwent major abdominal surgery on the duration of general anesthesia, hemodynamic and sedation effect.

METHOD

This prospective, randomized, double-blinded clinical trial included 50 patients who were 20 to 60 years of age and admitted for major abdominal surgery. The patients were randomly assigned by a computer-generated random numbers table to sedation with DEX plus midazolam (DM group) (n=25) or DEX plus propofol (DP group) (n=25). In the DM group, patients received a bolus dose of 0.1 mg/kg of midazolam and immediately initiated the intravenous (i.v.) infusion of DEX 1 µg/kg over a 10 min and 0.5 µg/kg/hr by continuous i.v. infusion within operation period. In the DP group, patients received pre-anesthetic i.v. DEX 1 µg/kg over 15 min before anesthesia induction and 0.2-1 µg/kg/hr by continuous i.v. infusion during the operative period. After preoxygenation for at least 2 min, during the surgery, patients received propofol infusion dose of 250 μg/kg/min for 15 min then a basal infusion dose of 50 μg/kg/min. The bispectral index (BIS) value, as well as mean arterial pressure (MAP), heart rate (HR), respiratory rate (RR), oxygen saturation (SaO2), percutaneous arterial oxygen saturation (SpO2) and end-tidal carbon dioxide tension (ETCO2) were recorded before anesthesia (T0), during anesthesia (at 15-min intervals throughout the surgical procedure), by a blinded observer. Evidence of apnea, hypotension, hypertension and hypoxemia were recorded during surgery.

RESULTS

The hemodynamic changes, including HR, MAP, BIS, VT, SaO2, and RR had a downward tendency with time, but no significant difference was observed between the groups (P>0.05). However, the two groups showed no significant differences in ETCO2 and SPO2 values in any of the assessed interval (P>0.05). In this study, the two groups showed no significant differences in the incidence of nausea, vomiting, coughing, apnea, hypotension, hypertension, bradycardia and hypoxemia (P>0.05). Respiratory depression and serious adverse events were not reported in either group. Extubation time after surgery was respectively 6.3 ± 1.7 and 5.8 ± 1.4 hr. in the DM and DP groups and the difference was not statistically significant (P= 0.46).

CONCLUSION

Our study showed no significant differences between the groups in hemodynamic and respiratory changes in each of the time intervals. There were also no significant differences between the two groups in the incidence of complication intra and post-operative. Further investigations are required to specify the optimum doses of using drugs which provide safety in cardiovascular and respiratory system without adverse disturbance during surgery.

Comparative Safety Profiles of Sedatives Commonly Used in Clinical Practice: A 10-Year Nationwide Pharmacovigilance Study in Korea

This study aims to compare the prevalence and seriousness of adverse events (AEs) among sedatives used in critically ill patients or patients undergoing invasive procedures and to identify factors associated with serious AEs. Retrospective cross-sectional analysis of sedative-related AEs voluntarily reported to the Korea Adverse Event Reporting System from 2008 to 2017 was performed. All AEs were grouped using preferred terms and System Organ Classes per the World Health Organization-Adverse Reaction Terminology. Logistic regression was performed to identify factors associated with serious events. Among 95,188 AEs, including 3132 (3.3%) serious events, the most common etiologic sedative was fentanyl (58.8%), followed by pethidine (25.9%). Gastrointestinal disorders (54.2%) were the most frequent AEs. The most common serious AE was heart rate/rhythm disorders (33.1%). Serious AEs were significantly associated with male sex; pediatrics; etiologic sedative with etomidate at the highest risk, followed by dexmedetomidine, ketamine, and propofol; polypharmacy; combined sedative use; and concurrent use of corticosteroids, aspirin, neuromuscular blockers, and antihistamines (reporting odds ratio > 1, p < 0.001 for all). Sedative-induced AEs are most frequently reported with fentanyl, primarily manifesting as gastrointestinal disorders. Etomidate is associated with the highest risk of serious AEs, with the most common serious events being heart rate/rhythm disorders.

Effectiveness of nebulized dexmedetomidine for treatment of post-dural puncture headache in parturients undergoing elective cesarean section under spinal anesthesia: a randomized controlled study

PURPOSE

The need for effective treatment for post-dural puncture headache (PDPH) is a growing research entity. This study aimed to test the effectiveness of additional dexmedetomidine (DEX) to PDPH conservative management and evaluate its cerebral hemodynamic effects trans-cranial Doppler.

METHODS

This prospective randomized double-blind controlled trial was conducted on 43 post-partum females suffering from PDPH with visual analog score (VAS) ≥ 4 and Lybecker score ≥ 2. The study subjects were allocated into control group [n = 22] received nebulization of 4 mL 0.9% saline and DEX group [n = 21] received nebulization of 1 µg/kg DEX diluted in 4 mL 0.9% saline twice daily that was continued until achieving VAS score ≤ 3 and Lybecker score < 2 and/or for a maximum of 72 h. Both groups received routine conservative management. The primary outcome was the VAS and Lybecker scores and the secondary results were the DEX effects on cerebral vessels and the occurrence of any adverse effects.

RESULTS

VAS and Lybecker scores were significantly lower in DEX group. The middle cerebral artery mean flow velocity was significantly lower, and the pulsatility index was considerably higher after DEX nebulization compared to placebo. Two patients in the control group were indicated for epidural blood patch.

CONCLUSION

The addition of DEX nebulization (1 µg/kg twice daily) to the PDPH conservative care effectively relieved the symptoms and lowered pain scores which could be due to its analgesic and cerebral vasoconstrictive effects.

TRIAL REGISTRATION

This study was approved by the research ethical committee of Faculty of Medicine, Zagazig University with the reference number (ZU-IRB#: 6075/26-4-2020) and it was registered under clinicaltrials.gov (NCT04327726).

Risk Factor for Additional Intravenous Medication during Transforaminal Full-endoscopic Lumbar Discectomy under Local Anesthesia

Transforaminal full-endoscopic lumbar discectomy (TELD) can be performed under local anesthesia. However, there have been no reports on risk factors for a change in vital signs or the need for additional medications to maintain adequate analgesia during this procedure. The purpose of this study was to identify risk factors for additional intravenous medication during TELD under local anesthesia. The following factors were retrospectively evaluated in 113 consecutive patients who underwent TELD under local anesthesia at our institution: demographic characteristics, radiological features at the intervertebral disc level, distance between the superior articular process and the exiting nerve root, height of the intervertebral disc, height of the bulging disc, height of the intervertebral foramen, and distance from the insertion site to the spinous process on magnetic resonance imaging (MRI) and computed tomography (CT) scans of the lumbar spine. Logistic regression analysis was performed to determine factors associated with the need for additional drugs. In all, 23 cases (20.4%) required additional intraoperative medications because of hypertension, hypotension, bradycardia, or pain. Logistic regression analysis revealed that age (partial regression coefficient 0.05, p = 0.02) and bulging disc height (partial regression coefficient −0.7, p = 0.003) influenced the need for additional drugs. There were significant associations of need for additional intravenous medication with older age (>62 years) and a smaller bulging disc height (<8.2 mm). Patients with these factors require close monitoring for changes in vital signs or increasing pain when performing TELD under local anesthesia and may need additional intravenous medication.

Butorphanol in combination with dexmedetomidine provides efficient pain management in adult burn patients

OBJECTIVE

This study aimed to compare the sedation and analgesic effects of butorphanol alone and butorphanol in combination with dexmedetomidine on dressing changes in adult burn patients.

METHOD

From June 2016 to May 2019, 44 adult burn patients from our department were enrolled in this prospective, double-blinded study. Their total burn surface area (TBSA) varied from 10% to 30%; and the depth of burn injury ranged from second degree to third degree. The patients were randomized into two groups. In the control group, butorphanol combined with saline was injected into the body via venous route during dressing change. In the observation group, butorphanol in combination with dexmedetomidine was injected. The variation in mean blood pressure, heart rate, respiratory rate, and peripheral oxygen saturation were recorded at various time-points of the procedure. Visual Analogue Scale (VAS) of pain and Ramsay Sedation Scores (RSS) were also recorded at different time points. Consumption of butorphanol and adverse events in these two groups were compared.

RESULTS

The mean blood pressure and heart rate were significantly decreased in the observation group before butorphanol injection (P < 0.05) and before the dressing change (P < 0.05). The respiratory rates and peripheral oxygen saturation of these two groups showed no significant differences at all time points (P > 0.05). Patients in the observation group had lower VAS scores during dressing change (P < 0.05). The RSS Scores in the observation group were higher than those in the control group during (P < 0.05) and after the dressing change (P < 0.05). The consumption of butorphanol was more in the control group (P < 0.05), and the adverse events recorded in the control group were higher (P < 0.05).

CONCLUSION

Butorphanol combined with dexmedetomidine can reduce analgesic use of butorphanol during dressing change. This combination resulted in a higher sedation score and fewer adverse effects.

Efficacy of dexmedetomidine versus propofol in patients undergoing endoscopic transnasal transsphenoidal pituitary tumor resection

Background:

Dexmedetomidine is associated with good perioperative hemodynamics together with decreased opioid requirements. Furthermore, propofol has been used to achieve hypotensive anesthesia as a part of total intravenous anesthesia.

Aims:

This study was performed to compare dexmedetomidine and propofol on the adequacy of hypotensive anesthesia during transsphenoidal resection of pituitary tumors.

Patients and Methods:

A total of 110 cases were included in this prospective randomized study. They were randomized into two equal groups; Group D commenced on Dexmedetomidine, and Group P, which received propofol. Comparing intraoperative hemodynamic parameters and the Boezaart Bleeding Scale was our primary outcome. The secondary outcomes included isoflurane and propranolol consumption, recovery, postoperative analgesic profile.

Statistical Analysis:

IBM's SPSS Statistics (Statistical Package for the Social Sciences) for Windows (version 25, 2017) was used for the statistical analysis of the collected data. Shapiro–Wilk test was used to check the normality of the data distribution. The quantitative variables were expressed as mean and standard deviation, whereas the categorical variables were expressed as frequency and percentage. Independent sample t and Mann − Whitney tests were used for the comparison of parametric and nonparametric continuous data, respectively. For pair-wise comparison of data (within-subjects), the follow-up values were compared to their corresponding basal value using the paired samples t-test or Wilcoxon matched-pairs signed-ranks test. Fisher exact and Chi-square tests were used for inter-group comparison of nominal data using the crosstabs function.

Results:

Age, gender, body mass index, and systemic comorbidities did not significantly differ between the two groups. Furthermore, heart rate and blood pressure were comparable at baseline, during operation, and after extubation. Boezaart score, blood loss, isoflurane, and propranolol consumption were also comparable between the two groups. Group D expressed significantly longer emergence and extubation times than Group P. Nevertheless, cases in the same group expressed lower Visual Analog Scale values and postoperative analgesic requirements.

Conclusion:

Although Dexmedetomidine and propofol are associated with comparable intraoperative hemodynamic changes, the former drug appears to be superior regarding pain control, postoperative analgesic requirement.

Effects of dexmedetomidine as a perineural adjuvant for femoral nerve block: A systematic review and meta-analysis

Background

Femoral nerve block (FNB) is one of the first-line analgesic methods for patients following lower extremity surgery. However, FNB with local anesthetics alone exert limited potency and supplemental opioids are often required. Dexmedetomidine (DEX) has been used to improve the analgesic effects of FNB. The present systematic review and meta-analysis were conducted to evaluate the effectiveness of DEX as an adjuvant to local anesthetics for FNB.

Methods

Randomized controlled trials comparing the effects of DEX versus sham control in combination with local anesthetics for FNB were included in this meta-analysis. Postoperative pain scores, duration of analgesic effects, and postoperative narcotic consumption were outcomes of interest. This research was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statements.

Results

A total of 9 studies encompassing 580 participants were included for data synthesis after critical evaluation. DEX as an adjuvant with local anesthetics for FNB significantly relieved pain intensity at 12, 24 and 48 hours after surgery, both at rest (standardized mean difference -1.34 [95% CI -1.87 to -0.82], P<0.00001 at 12 h; -1.26 [-1.90 to -0.0.63], P<0.0001 at 24 h; and -1.34; [-2.18 to -0.50], P = 0.002 at 48 h) and with movement (-1.30 [-2.17 to -0.43], P = 0.004 at 12 h; -1.02 [-1.31 to -0.72], P<0.00001 at 24h; and -1.33 [-2.03 to -0.63], P = 0.0002); it also significantly prolonged analgesic duration (mean difference 7.23 h [95% CI 4.07 to 10.39], P<0.00001) and decreased opioid consumption (mean difference of morphine equivalent -12.13 mg [95% CI -23.36 to -0.89], P<0.00001). Regarding safety, DEX use increased the rate of hypotension (odds ratio 4.10, 95% CI 1.40 to 12.01, P = 0.01).

Conclusion

DEX as an adjuvant to local anesthetics for FNB improves analgesia, prolongs analgesic duration and reduces supplemental opioid consumption; but increases hypotension.

Addition of dexmedetomidine to ropivacaine for local infiltration anaesthesia improves analgesic efficacy after tonsillectomy and adenoidectomy: A randomized controlled trial

OBJECTIVES

The aim of this study was to determine whether the addition of dexmedetomidine to ropivacaine for local infiltration anaesthesia was more effective than ropivacaine alone in attenuating pain after tonsillectomy and adenoidectomy.

METHODS

This was a double-blind randomized clinical trial. One hundred and twenty children scheduled for tonsillectomy and adenoidectomy using a combination of general anaesthesia and local infiltration anaesthesia were randomized into the dexmedetomidine plus ropivacaine group (DR) and ropivacaine group (R). The children were locally infiltrated with 1 μg kg^-1 dexmedetomidine and 0.25% ropivacaine in the DR group or 0.25% ropivacaine alone in the R group. In both groups, local infiltration anaesthesia was performed using 5 ml of solution. The pain scores were recorded at the 1st, 4th, 8th, 12th, 16th, 20th, and 24th hours after surgery using the Face Legs Activity Cry Consolability (FLACC) scale. When the pain score exceeded 4, paracetamol syrup (15 mg kg^-1) was administered as a rescue analgesic. Time to the first administration of analgesic was recorded.

RESULTS

8th, 16th, 20th, and 24th hours after surgery, the children in the DR group had lower pain scores than those in the R group (P<0.05). The time to the first administration of analgesic was significantly longer in the DR group (mean: 10.4 h, range: 9.4-11.4 h) than in the R group (mean: 8.1 h, range: 7.3-8.8 h) (P < 0.001).

CONCLUSION

The addition of dexmedetomidine to ropivacaine for local infiltration anaesthesia effectively improved the efficacy of analgesia and extended the duration of analgesia after tonsillectomy and adenoidectomy.

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.

Adding Dexmedetomidine to Articaine Increases the Latency of Thermal Antinociception in Rats

Articaine is a low-toxicity local anesthetic that is widely used in dentistry. Typically, epinephrine is added to prolong the duration of articaine local anesthesia; however, epinephrine exhibits adverse effects. Low-dose dexmedetomidine (DEX), an α₂-adrenoreceptor agonist, reportedly prolongs local anesthesia without notable adverse cardiovascular effects. The purpose of this study was to assess whether a combination of low-dose DEX and articaine would provide a low-toxicity local anesthetic option for dental procedures without adverse cardiovascular effects. Thus, this study investigated whether DEX could prolong the local anesthetic effect of articaine using a rat model of pain. Adult male Wistar rats (N = 44; 11 per group) received a 50-μL subcutaneous injection into the plantar surface of the hind paws; injections were composed of either normal saline, 4% articaine (2 mg articaine), combined 5 μg/kg DEX and 4% articaine (1.25 μg DEX + 2 mg articaine), or combined epinephrine (1:100,000) and 4% articaine (0.9 μg epinephrine + 2 mg articaine). Subsequent acute pain perception was determined by paw withdrawal movement in response to infrared radiant heat stimulation of the plantar region. Paw withdrawal latency was tested at 5-minute intervals. Paw withdrawal latency values at 35 and 40 minutes were 3.83 ± 1.76 and 3.29 ± 1.43 seconds for articaine alone, 7.89 ± 2.72 and 7.25 ± 3.37 seconds for DEX and articaine, and 8.95 ± 2.28 and 8.17 ± 3.01 seconds for epinephrine and articaine. DEX prolonged the paw withdrawal latency of articaine for up to 35 minutes (p = .015) but not 40 minutes after injection (p = .052) when compared to articaine alone. The combination of DEX and articaine can provide effective local anesthesia for up to 35 minutes after injection.

Dexmedetomidine combined with ropivacaine in ultrasound-guided tranversus abdominis plane block improves postoperative analgesia and recovery following laparoscopic colectomy

The present prospective, double blind, randomized clinical study was designed to evaluate whether dexmedetomidine (Dex) combined with ropivacaine for tranversus abdominis plane (TAP) block could improve analgesic quality and duration, and promote recovery following laparoscopic colectomy. Following induction of anesthesia, ultrasound-guided bilateral TAP block was performed in 60 patients scheduled for elective laparoscopic colectomy with either 20 ml of 0.375% ropivacaine plus 2 ml normal saline 0.9% (R group), or 20 ml of 0.375% ropivacaine plus 2 ml Dex (0.5 µg/kg) (RD group). Visual analogue scale (VAS) score for pain, sedation level, length of hospital stay (LOS), and bowel function recovery time and associated complications were recorded. Overall patient satisfaction with postoperative pain management was also assessed. The hemodynamic variables were not significantly different between the two groups during the surgery. However, the duration of analgesia was significantly longer in the RD group compared with the R group (P<0.05). VAS scores at 1, 2, 6 and 12 h following surgery were significantly decreased in the RD group compared with those in the R group (P<0.05). There was no significant difference in sedation level between the two groups. Notably, postoperative nausea and vomiting in the RD group was significantly decreased compared with those in the R group in the first 24 h (P<0.05). There were no serious adverse events in any group. Furthermore, 90.0 and 66.7% patients were satisfied with the postoperative pain management in the RD group and R group, respectively. The postoperative first bowel movement time was significantly shorter in the RD group compared with the R group (P<0.05). However, the LOS was not significantly different between the two groups. In conlusion, the addition of Dex to ropivacaine could significantly improve the analgesic quality and duration of TAP block, which in turn promotes recovery following laparoscopic colectomy.

Comparison of midazolam and butorphanol combined with ketamine or dexmedetomidine for chemical restraint in howler monkeys (Alouatta guariba clamitans) for vasectomy

BACKGROUND

This study evaluated and compared cardiorespiratory and blood gas parameters, as well as sedation, analgesia and recovery of two protocols: ketamine (10 mg/kg) or dexmedetomidine (10 μg/kg), with midazolam (0.5 mg/kg) and butorphanol (0.3 mg/kg), IM (KBM and DBM, respectively) in brown howler monkeys (Alouatta guariba clamitans).

MATERIAL AND METHODS

Twelve brown howler monkeys were selected in two groups and evaluated for cardiorespiratory parameters and sedation, from 5-30 minutes after latency. Blood gas and arterial lactate were taken at 5 and 30 minutes. In the end, time and quality of recovery were evaluated.

RESULTS

The HR in DBM group was significantly lower at all times. The sedation score was higher in DBM. Recovery in DBM was faster. All animals had moderate hypoxaemia.

CONCLUSION

Both protocols produce satisfactory anaesthesia and analgesia, but DBM provides deeper sedation with faster recovery. Oxygen supplementation is recommended in both due to hypoxaemia.

Probing the Role of Ion-Pair Strategy in Controlling Dexmedetomidine Penetrate Through Drug-in-Adhesive Patch: Mechanistic Insights Based on Release and Percutaneous Absorption Process

The purpose of present study was to develop a controlled release drug-in-adhesive patch for transdermal delivery of dexmedetomidine (Dex) using ion-pair technique. Based on the in vitro transdermal experiment, the role of ion-pair on the Dex release behavior and percutaneous absorption process was also investigated. Fourier transform infrared spectroscopy (FTIR), molecular modeling, differential scanning calorimetry (DSC), and rheological test were conducted to probe the effect of ion-pair on the Dex release from patch. Besides, the tape stripping test, attenuated total reflectance Fourier transform infrared (ATR-FTIR), and molecular simulation were carried out to elaborate the action of ion-pair on the Dex percutaneous permeation process. Results showed that the optimized patch prepared with Dex-salicylic acid (SA) showed zero-order skin permeation profile within 24 h; Dex-SA had greater hydrogen bonding formation potential with pressure sensitive adhesive (PSA) than Dex, which resulted in the decrease in the formation ability of free volume of PSA and the increase with the improvement of mechanical strength and chain stiffness of PSA and thus controlled the release rate of Dex from transdermal patch. Besides, the physicochemical properties of Dex such as molecular weight and octanol/water partition coefficient were changed after forming ion-pair with SA, which decreased the permeation ability of Dex. In conclusion, a controlled release drug-adhesive patch for Dex was developed and the mechanism study of ion-pair on the Dex release and percutaneous permeation process was proposed at molecular level.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Attenuation of haemodynamic responses to laryngoscopy and endotracheal intubation with dexmedetomidine: A comparison between intravenous and intranasal route

Background and Aims:

Haemodynamic changes during endotracheal intubation are major concerns in general anaesthesia This study compared the efficacy of intranasal and intravenous dexmedetomidine (DEX) to attenuate the stress response of laryngoscopy and endotracheal intubation.

Methods:

In this prospective, randomised, double-blinded study, 70 adults were divided into two groups [Group D_IV(n=35) and Group D_IN(n=35)]. D_IV group received intravenous dexmedetomidine (DEX) infusion (0.5 μg/kg) over 40 min and D_IN group received intranasal dexmedetomidine (1 μg/kg) 40 min before induction. The primary objective was the comparison the mean arterial pressure (MAP) between two groups from 40 min before induction at every 10 min intervals till induction of anaesthesia, at the time of intubation, thereafter every 1 min interval till 5 min, at 7 min and 10 min after intubation. The secondary outcomes were comparison of heart rate, systolic and diastolic blood pressure along with sedation and other adverse effects. Statistical analysis was with Statistica 6.0 and Graph Pad prism version 5.

Results:

In both the groups, all the haemodynamic parameters were maintained within (20% of baseline values) throughout the study period. There was no statistically significant difference in MAP between two groups (P>0.05). Preoperative sedation score was significantly higher in the D_IV group than the D_IN group (P = 0.014).

Conclusion:

Like IV DEX, intranasal DEX can also attenuate the haemodynamic stress responses of laryngoscopy and endotracheal intubation without significant differences in MAP between two groups.

Dexmedetomidine vs propofol as sedation for implantation of neurostimulators: A single-center single-blinded randomized controlled trial

BACKGROUND

During the lead implantation of most spinal cord neurostimulators, the patient has to be comfortable and without pain. However, the patient is expected to provide feedback during electrical mapping. Titrating sedatives and analgesics for this double goal can be challenging. In comparison with our standard sedative agent propofol, the pharmacological profile of dexmedetomidine is more conducive to produce arousable sedation. The latter, however, is associated with hemodynamic side effects. We investigated whether dexmedetomidine is preferable over propofol during neurostimulator implantation.

METHODS

This single-center single-blinded randomized controlled trial included 72 patients with an indication for a neurostimulator, randomized to sedation with either propofol (0.5 mg/kg for 10 minutes, followed by 2.0 mg/kg/h) or dexmedetomidine (1 μg/kg for 10 minutes, followed by 0.6 μg/kg/h). The primary outcome was patient satisfaction with the sedation. The secondary outcomes were patient's and operator's comfort, number of titration adjustments, standard intraoperative hemodynamic and respiratory parameters and side effects.

RESULTS

Data of 69 patients (dexmedetomidine n = 35; propofol n = 34) were analyzed. Those receiving dexmedetomidine were more satisfied with the sedation than those receiving propofol; i.e. with sedation delivery (median 100.0 vs 83.3, P < .01), procedural recall (median 95.8 vs 83.3, P = .03), and sedation side effects (median 90.0 vs 83.3, P = .01). Fewer changes in the dexmedetomidine titration were necessary to maintain arousable sedation. Over time, mean arterial pressure and heart rate were significantly lower in the dexmedetomidine group. Hemodynamic side effects were comparable across groups.

CONCLUSIONS

Dexmedetomidine sedation resulted in higher patient satisfaction and allowed for better arousable sedation than sedation with propofol. Although differences in hemodynamic parameters were found between the groups, these differences were not regarded as clinically relevant.

A rat model of somatosensory-evoked reflex seizures induced by peripheral stimulation

OBJECTIVE

We introduce a novel animal model of somatosensory stimulation-induced reflex seizures which generates focal seizures without causing damage to the brain.

METHODS

Specifically, we electrically stimulated digits or forepaws of adult rats sedated with dexmedetomidine while imaging cerebral blood volume and recording neurophysiological activity in cortical area S1FL. For the recordings, we either inserted a linear probe into the D3 digit representation or we performed surface electrocorticography (ECoG) recordings.

RESULTS

Peripheral stimulation of a digit or the forepaw elicited seizures that were followed by a refractory period with decreased neuronal activity, or another seizure or normal response. LFP amplitudes in response to electrical pulses during the seizures (0.28 ± 0.03 mV) were higher than during normal evoked responses (0.25 ± 0.05 mV) and refractory periods (0.2 ± 0.08 mV). Seizures generated during the stimulation period showed prolonged after-discharges that were sustained for 20.9 ± 1.9 s following the cessation of the stimulus. High-frequency oscillations were observed prior to and during the seizures, with amplitudes higher than those associated with normal evoked responses. The seizures were initially focal. Optical imaging of the cerebral blood volume response showed that they propagated from the onset zone to adjacent cortical areas, beyond the S1FL representation of the stimulated digit or forepaw. The spatial extent during seizures was on average 1.74 times larger during the stimulation and 4.1 times following its cessation relative to normal evoked responses. Seizures were recorded not only by probes inserted into cortex but also with ECoG arrays (24.1 ± 5.8 seizures per rat) placed over the dura matter, indicating that the seizures were not induced by damage caused by inserting the probes to the cortex. Stimulation of the forepaw elicited more seizures (18.8 ± 8.5 seizures per rat) than stimulation of a digit (1.7 ± 0.7). Unlike rats sedated with dexmedetomidine, rats anesthetized with urethane showed no seizures, indicating that the seizures may depend on the use of the mild sedative dexmedetomidine.

SIGNIFICANCE

Our proposed animal model generates seizures induced by electrical sensory stimulation free of artifacts and brain damage. It can be used for studying the mechanisms underlying the generation and propagation of reflex seizures and for evaluating antiepileptic drugs.

Premedication with dexmedetomidine to reduce emergence agitation: a randomized controlled trial

Background

Nasal bone fracture is the most common type of facial fracture, and the high incidence of severe emergence agitation occurring after closed reduction of the nasal bone fracture can be challenging to manage. The purpose of this trial was to evaluate whether pre-operative administration of dexmedetomidine is effective in reducing the incidence and severity of emergence agitation in adults undergoing closed reduction of nasal bone fractures.

Methods

In this randomized controlled trial, 90 patients who were scheduled to undergo closed reduction of a nasal bone fracture were prospectively included and were randomly assigned to either the control group (n = 45; 0.9% saline infusion) or the dexmedetomidine group (n = 45; 1 μ/kg over 10 min, pre-operatively). The primary endpoint was Aono’s four-point scale scores after anesthesia. The recovery time and numeric rating scale score were assessed as secondary endpoints.

Results

Aono’s four-point scale scores were lower in the dexmedetomidine group than in the control group (median: 1 [1] vs. 1 [1, 2], 95% confidence interval of difference: 0.01 to 0.02, P = 0.02). The number, severity, and duration of agitation episodes were significantly lower in the dexmedetomidine group than in the control group. Furthermore, the number of patients exhibiting intraoperative movement was lower in the dexmedetomidine group.

Conclusions

Pre-operative administration of dexmedetomidine demonstrated several significant benefits, such as a lower incidence of emergence agitation, reduced agitation severity, and a shorter duration of agitation. Additionally, we observed more stable maintenance of intraoperative anesthesia with less movement during the surgery.

Trial registration

Identifier: KCT0000585 (registration date: 12–19- 2012).

Dexmedetomidine Use in a Case of Severe Cancer Pain

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

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.

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

BACKGROUND

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

METHODS

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

DISCUSSION

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

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

BACKGROUND

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

METHODS

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

DISCUSSION

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

Intraoperative dexmedetomidine infusion is associated with reduced emergence agitation and improved recovery profiles after lung surgery: a retrospective cohort study

Purpose

This retrospective cohort study aimed to investigate the association between intraoperative dexmedetomidine infusion and emergence agitation (EA), and recovery profiles after lung surgery in adult patients. It was hypothesized that dexmedetomidine was associated with reduced EA and improved recovery profiles.

Patients and methods

A single-center chart review was conducted on elective lung surgeries in adults between January and December 2016. The primary outcome was the incidence of EA in postanesthesia care units (PACUs). The secondary outcomes included rescue analgesia, shivering, time to extubation, residual sedation, postoperative pulmonary events, duration of PACU stay, length of hospital stay, and intraoperative hemodynamic changes. Univariate and multivariate regression analyses were used to analyze data.

Results

Among 2,468 patients, 814 received an intraoperative dexmedetomidine infusion. Intraoperative dexmedetomidine infusion was associated with a lower incidence of EA (10.9% vs 15.0%; adjusted OR, 0.67; 95% CI, 0.51–0.87; P=0.003), rescue analgesia (7.6% vs 12.2%; adjusted OR, 0.63; 95% CI, 0.47–0.86; P=0.003), shivering (4.2% vs 6.6%; adjusted OR, 0.58; 95% CI, 0.38–0.88; P=0.010), and intraoperative bradycardia (18.6% vs 12.6%; adjusted OR, 1.51; 95% CI, 1.19–1.92; P=0.001). No differences were observed in residual sedation, duration of PACU stay, postoperative pulmonary events, and length of hospital stay between the groups.

Conclusion

This retrospective study suggested that intraoperative dexmedetomidine infusion was associated with a lower incidence of EA, rescue analgesia, and shivering in adults after lung surgery. Intraoperative bradycardia was the main side effect.

Thoracic Paravertebral Block with Adjuvant Dexmedetomidine in Video-Assisted Thoracoscopic Surgery: A Randomized, Double-Blind Study

Background: The addition of the adjuvant dexmedetomidine to a nerve block improves the quality of the block and reduces perioperative opioid consumption. The aim of this study was to assess the effect of dexmedetomidine as an adjuvant for the thoracic paravertebral block (TPVB) in postoperative pain control after video-assisted thoracoscopic surgery (VATS). Methods: Sixty-six males, aged 15–40 years, with spontaneous pneumothorax scheduled for VATS wedge resection were enrolled. Following surgery, ultrasound-guided TPVB was performed on the T3 and T5 levels with 30 mL of 0.5% ropivacaine, plus adjuvant dexmedetomidine 50 μg or normal saline. The primary outcome was cumulative fentanyl consumption at 24 h. Pain severity, the requirement for additional rescue analgesics, hemodynamic variations, and side effects were also evaluated. Results: Median postoperative cumulative fentanyl consumption at 24 h was significantly lower in the dexmedetomidine group (122.6 (interquartile range (IQR) 94.5–268.0) μg vs. 348.1 (IQR, 192.8–459.2) μg, p-value = 0.001) with a Hodges–Lehman median difference between groups of 86.2 (95% confidence interval (CI), 4.2–156.4) mg. Coughing numeric rating scale (NRS) was lower in the dexmedetomidine group at postoperative 2, 4, 8, and 24 h. However, resting NRS differed significantly only after 4 h postoperative. Conclusions: Dexmedetomidine as an adjunct in TPVB provided effective pain relief and significantly reduced opioid requirement in VATS.

Efficacy of dexmedetomidine in reducing post-operative pain and improving the quality of recovery in patients with burn wounds undergoing tangential excision skin grafting

Burn-induced acute post-operative pain and the associated stress response may result in prolonged convalescence. The present study investigated the effects of dexmedetomidine (DEX) administration on post-operative pain and the quality of recovery following surgical treatment of moderate-to-severe burn injuries. A total of 60 adult patients undergoing tangential excision skin grafting were randomized into two groups. The DEX group (Group D) received an intravenous (i.v.) single-dose bolus injection of DEX 0.5 µg/kg >10 min prior to induction of anesthesia. Patient-controlled intravenous analgesia (PCIA) was provided to the patients from the end of the surgery, which consisted of 100 µg sufentanil plus 200 µg DEX. The control group (Group C) received an equal volume of normal saline as a pre-operative bolus and post-operative PCIA of 100 µg sufentanil infusion. The Visual Analogue Scale (VAS) score at rest and during movement, the cumulative dose of sufentanil and the 40-item quality of recovery questionnaire (QoR-40) score were assessed at various time-points after the surgery. During the first 24 h post-surgery, patients in Group D exhibited a lower VAS score at rest and during movement, a lower number of PCIA pump presses (29.17±1.91 vs. 34.13±2.73) and lower sufentanil consumption (62.58±0.96 vs. 65.27±1.26) compared with those in Group C (P<0.05). Furthermore, the QoR-40 recovery score of patients in Group D at 24 h post-surgery was higher compared with that in Group C (P<0.01). In conclusion, the present study indicated that a pre-operative bolus of DEX (0.5 µg/kg) followed by DEX plus sufentanil by PCIA subsequent to surgery improved the quality of analgesia and promoted the quality of recovery at 24 h following tangential excision skin grafting treatment of patients with moderate-to-severe burn injuries compared to PCIA of 100 µg sufentanil only. The present study was retrospectively registered with the trial registration no. ChiCTR1800016646 (date of registration, 14/06/2018).