Dexmedetomidine For Sedation Research Articles

EEG response of dexmedetomidine during drug induced sleep endoscopy.

Dexmedetomidine is one of the anesthetics of choice for drug induced sleep endoscopy (DISE), with advantages including limited respiratory depression, analgesia, and decreased incidence of emergence delirium. However, challenges with determining sedation levels and prolonged recovery have limited its usage. An improved understanding of the effect of dexmedetomidine on the level of sedation and the corresponding electroencephalographic (EEG) changes could help overcome these barriers. Fifty-one patients received dexmedetomidine sedation with Richmond Agitation-Sedation Scale (RASS) score assessment and continuous EEG monitoring via SedLine for DISE. We constructed a pharmacokinetic model to determine continuous dexmedetomidine blood concentration. From the SedLine, we extracted the patient state index (PSI), and from the EEG we calculated the spectral edge frequency 95% (SEF95) and the correlation dimension (CD), a type of fractal dimension used to assess the complexity of a system. These metrics were subsequently compared against one another and with the dexmedetomidine concentration. Our pharmacokinetic model yielded a two-compartment model with volumes of 51.8 L and 106.2 L, with clearances of 69.5 and 168.9 L/h, respectively, and a time to effect of 9 min, similar to prior studies. Based on this model, decreasing RASS score, SEF95, CD, and PSI were all significantly associated with increasing dexmedetomidine concentration (p < 0.001, p = 0.006, p < 0.001 respectively). The CD, SEF95, and PSI better captured the effects of increasing dexmedetomidine concentration as compared to the RASS score. Simulating dexmedetomidine concentration based on titration to target levels derived from CD and PSI confirmed commonly used dexmedetomidine infusion dosages. Dexmedetomidine use for DISE confirmed previous pharmacokinetic models seen with dexmedetomidine. Complex EEG metrics such as PSI and CD, as compared to RASS score and SEF95, better captured changes in brain state from dexmedetomidine and have potential to improve the monitoring of dexmedetomidine sedation.

The effect on vital signs of concomitant administration of nicardipine and dexmedetomidine sedation after spinal anesthesia: A double-blind, randomized controlled trial.

We evaluated heart rate (HR) and blood pressure (BP) trends when nicardipine (NCD) was co-administered during dexmedetomidine (DEX) sedation after spinal anesthesia. Sixty patients aged 19 to 65 were randomly assigned to the DEX or DEX-NCD groups. Five minutes after infusion of the loading dose of DEX, the NCD was administered intravenously at a rate of 5 μg/kg for 5 minutes in the DEX-NCD group. The study starting point was set at 0 minute when the DEX loading dose was initiated. The primary outcomes were the differences in HR and BP between the 2 groups during the study drug administration. Secondary outcomes included the number of patients whose HR was < 50 beats per minute (bpm) after the DEX loading dose infusion, and associated factors were evaluated. The incidence of hypotension in the postanesthesia care unit, postanesthesia care unit length of stay, postoperative nausea and vomiting, postoperative urinary retention, time to first urination after spinal anesthesia, acute kidney injury, and postoperative hospital length of stay were evaluated. The HR was significantly higher at 14 minutes, and the mean BP was significantly lower at 10 minutes in the DEX-NCD group than in the DEX group. The number of patients with an HR < 50 bpm during surgery was significantly higher in the DEX group than in the DEX-NCD group at 12, 16, 24, 26, and 30 minutes. The DEX group and a low initial HR were independently associated with the occurrence of an HR < 50 bpm after DEX loading dose infusion. Postoperative outcomes were not significantly different between the 2 groups. Simultaneous administration of NCD during the administration of a loading dose of DEX prevented severe bradycardia. Co-administration of NCD may be considered in patients with a low initial HR when severe bradycardia is expected during the DEX loading dose infusion. NCD and DEX may be safely infused simultaneously without affecting postoperative complications (see Figure S1, Supplemental Digital Content, http://links.lww.com/MD/J241 , Graphical abstract).

Effect of Sedation Strategy on the Hospital Length of Stay and ICU Length of Stay after On-Pump Cardiac Surgeries

Over the past decades, many approaches have been changed in intensive care and in anesthesiology. Most of these changes were included in the guidelines now well known as fast-track protocols (protocols for enhanced recovery after surgery). Cardiac anesthesiology was not an exception. Preoperative, intraoperative and postoperative management of the patient are the main components of these protocols, which are aimed at reducing the length of stay (LOS) of patients in the hospital and intensive care units (ICU).&#x0D; The aim. To detect the relationship between the sedation strategy and the duration of the hospital LOS and the ICU LOS.&#x0D; Materials and methods. This was a randomized, controlled, parallel study. We analyzed 194 patients over 18 years of age who underwent cardiac surgical treatment using artificial blood circulation. Statistical data processing was carried out on the basis of GraphPad Prism 9.0 software.&#x0D; Results. According to our research, the average hospital LOS was 7.779 ± 2.844 days in the propofol group (n = 95), 7.188 ± 1.601 days in the dexmedetomidine group (n = 16). In the group where patients were sedated with a combination of drugs (n = 83), the average length of hospitalization was 5.904 ± 1.535 days. The average ICU LOS was 2.463 ± 1.090 days in the propofol group and 2.375 ± 1.360 days in the dexmedetomidine group. In the group where patients were sedated with a combination of drugs (n = 83), the average ICU LOS was 2.361 ± 0.8776 days. The hospital LOS of patients who were sedated with a combination of drugs was lower (p &lt; 0.0001). When comparing the ICU LOS, no difference was found in all three sedation groups (p = 0.3903).&#x0D; According to the analysis conducted in the propofol group, the ICU LOS was shorter in patients who did not receive vasoactive therapy (p = 0.0299). In the dexmedetomidine sedation group, no difference was found between the ICU LOS in patients with or without vasoactive support (p = 0.5289). In the group of patients who underwent sedation with a combination of drugs, the ICU LOS was shorter in the group of patients who underwent correction with vasoactive drugs (p &lt; 0.0001).&#x0D; Conclusion. Sedation with a drug combination (dexmedetomidine and propofol) may reduce hospital LOS (p &lt; 0.0001). There was no influence of any sedation strategy on the ICU LOS (p = 0.3903). Early initiation of vasoactive support with sedative drug combination (dexmedetomidine and propofol) shortens the ICU LOS (p &lt; 0.0001).

THE EFFECT OF SEDATION STRATEGY ON THE FREQUENCY OF POSTOPERATIVE ARRHYTHMIAS AFTER CARDIAC SURGERIES WITH BYPASS

Introduction: Postoperative arrhythmias are a frequent problem after surgical interventions, both noncardiac and cardiac surgeries. A 20% higher frequency of rhythm disturbances occurs in patients after cardiac surgery. Postoperative arrhythmia has many variations. Such arrhythmias include atrial fibrillation, atrial flutter, ventricular arrhythmias, and bradyarrhythmias. There are many conflicting facts about the effect of sedative drugs, which are most often used at the moment: propofol, dexmedetomidine, on reducing the frequency of postoperative arrhythmias. Purpose: To analyze whether there is a difference in the frequency of postoperative arrhythmia in patients in different groups sedated with propofol, dexmedetomidine and their combination. Materials and methods: This is a randomized controlled parallel study. The study included 356 patients over 18 years of age who underwent cardiac surgeries operative treatment. 194 patients were analyzed. Statistical data processing was carried out on the basis of GraphPad Prism 9.0 software. Results: Of the total number of patients in the propofol sedation group without prior rhythm disturbance, in whom arrhythmia was detected in the postoperative period, n=13 patients were registered. In the dexmedetomidine sedation group, postoperative arrhythmia was observed in 8 patients, which is also 50 % of the total number of patients in this group. Among 8 patients in whom postoperative arrhythmia was registered, 5 patients did not have rhythm problems before surgery. Of the total number of patients in the group of sedation with a combination of drugs without previous rhythm disturbance, postoperative arrhythmia was detected in 19 patients. When analyzing the frequency of postoperative arrhythmias, no difference in the frequency of postoperative arrhythmias has been detected in all three sedation strategies (p=0.1107). Conclusions: According to the data we obtained, no difference was found in the frequency of postoperative arrhythmias in patients after cardiac surgery in any of the sedation groups (p=0.1107).

The influence of intraoperative sedation on memory consolidation: a single-blind randomized controlled trial

The objective was to evaluate the effect of propofol and dexmedetomidine sedation on the short-term memory and long-term memory consolidation.Materials and methods. 80 patients with small orthopaedic interventions under subarachnoid anesthesia were included in the randomized controlled trial. Three groups were formed depending on the drug used: group P – propofol, group D – dexmedetomidine, group 0 – control. Emotionally neutral sets of words were tapped three times to evaluate the effect of sedation on long-term memory consolidation: stage1/set 1 – immediately before sedation (RASS 0, BIS 95–100), stage 2/set 2 – 5–10 minutes after the start of sedation (RASS «–1» – «–2», BIS 70–90), stage 3/set 3 – 10 minutes after sedation was terminated and consciousness was recovered (RASS 0, BIS 90–100). In addition, the impact of sedation on the ability to hold the received information in short-term memory was conducted 5 minutes after the presentation of the words at stage 2. Reproduction and recognition testing of all words was conducted the next day after operation to evaluate the effect of medical sedation on long-term memory consolidation.Results. Propofol and dexmedetomidine provided an inhibitory effect on the ability to hold information in short-term memory compared to control group (р &lt; 0.001 и р &lt; 0.001, respectively). Propofol had the most effect on short-term memory and the level of its amnesic effect was associated with the cognitive function of patients (p = 0.013, R² = 0.23, β = 0.472). The HADS points were as negative predictor of the reproduction of the word set 1 in control group (p = 0.05, R² = 0.136, β = –0.368) and recognition of the word set 3 in propofol group (р = 0.029, R² = 0.176, β = –0.420). Within 24 hours after operation, reproduction and recognition of word sets 2 depended on the degree of short-term memory impairment during sedation (F(1.65) = 19.317, p &lt; 0.001, ηp2 = 0.229 и F(1.65) = 21.638, p &lt; 0.0031, ηp2 = 0.250, respectively). Short-term memory test acted as a positive predictor of the reproduction of word set 3 in control group (p = 0.05, R² = 0.141, β = 0.376).Conclusion. Propofol and dexmedetomidine impair the ability to retain information in short-term and, consequently, long-term memory, and propofol has a more pronounced amnesic effect, which depends on the cognitive functions of patients. The sensitivity to the amnesic effect of the drugs depends on the individual characteristics of the patients.

Long-duration upper extremity surgery under brachial plexus block combined with intravenous dexmedetomidine sedation without an anesthesiologist

Dexmedetomidine (DEX) provides a unique conscious sedation without respiratory depression. We examined the usefulness of intravenous (IV) DEX sedation combined with brachial plexus block for long-duration upper extremity surgery without an anesthesiologist. We retrospectively reviewed 90 limbs of 86 patients and measured the actual operative time course in detail. The adverse events and the patient-reported outcomes regarding intraoperative pain and depth of sedation were evaluated. The mean total time of the operation, tourniquet use, and the IV DEX sedation were 150min, 132min, and 117min, respectively. The mean time between discontinuation of IV DEX sedation and completion of the operation was 51min. The intraoperative adverse events involved bradycardia (21%), hypotension (18%), and oxygen desaturation (3%). The mean visual analog scale scores of pain during brachial plexus block, surgical site pain, tourniquet pain, and depth of the sedation were 23.4mm, 0.14mm, 4.2mm, and 6.6mm, respectively. Furthermore, 96% patients expressed a preference for receiving anesthesia as brachial plexus block with IV DEX sedation. Long-duration upper extremity surgery, even longer than 2h, was feasible under brachial plexus block combined with IV DEX sedation without an anesthesiologist. For patients with low blood pressure and/or low heart rate, it is recommended to adjust the continuous infusion of IV DEX to less than 0.4µg/kg/h. To ensure that the patients are able to promptly leave the operating room fully awake, IV DEX infusion should be stopped at least 30min before finishing the operation.

High-Flow Nasal Oxygen (Optiflow) 10 L/min Therapy for an Unexpected Desaturation during Awake Craniotomy

Providing adequate sedation while ensuring normoventilation is a challenge during an awake craniotomy. The use of sedative agents may cause hypoventilation and apnea, inducing hypoxemia and hypercapnia. High-flow humidified nasal oxygen delivery devices have shown positive results in various clinical areas. Here, we present two case reports of patients undergoing awake craniotomy who experienced a sudden decrease in oxygen saturation while receiving dexmedetomidine sedation. Despite being aroused to take deep breaths, the patients’ oxygen saturation did not return to baseline. Arterial blood gas analysis (ABGA) revealed a significant fall in partial pressure of oxygen. To address the hypoxemia, we initiated high-flow nasal oxygen (Optiflow) 10 L/min instead of conventional oxygen treatment via nasal prong. Follow-up ABGA results showed that Optiflow 10 L/min effectively provided adequate oxygenation and prevented the retention of carbon dioxide. Optiflow 10 L/min was successful in managing the patients’ hypoxemia while maintaining adequate oxygenation, ventilation, and sedation during awake craniotomy.

Treatment of visual axis opacification and secondary membranes with Nd:YAG laser after pediatric cataract surgery under intranasal sedation.

To describe neodymium-doped yttrium-aluminum-garnet (Nd:YAG) laser treatment of visual axis opacification and secondary membranes in pediatric patients with cataracts under intranasal dexmedetomidine sedation. Twenty eyes of 17 patients with secondary membrane formation after cataract extraction were enrolled in this study. Intranasal dexmedetomidine sedation (3 ug/kg) was administered, and Nd:YAG laser (Ellex Super Q, Adelaide, Australia) procedures were performed with children in the sitting position with their chin supported on a laser delivery slit lamp. Preoperative and postoperative visual acuities were documented, and medical records were reviewed. The age of the patients ranged from 5 to 83 months (31.82 ± 27.73). Nineteen (95.0%) eyes had congenital cataracts and one (5.0%) had a traumatic cataract. Nd:YAG laser treatment of VAO with ten (50.0%) eyes, pupillary membranes with three (15.0%) eyes, pupillary cortical proliferation with six (30.0%) eyes, and anterior capsule contraction with one (5.0%) eye. Five (25.0%) eyes demonstrated visual acuity improvement, whereas six (30.0%) eyes remained unchanged after laser treatment. The recurrence rate was 30.0% and four eyes underwent a second Nd:YAG membranectomy. No side effects or tolerances due to sedative drugs were observed. Nd:YAG laser membranectomy under intranasal dexmedetomidine sedation was safely performed in children as young as 5 months old in a sitting position. This approach facilitates patient convenience, doctor proficiency, and cost reductions. Patients with recurrence can be treated by repeating the procedure.

Propofol Versus Dexmedetomidine Sedation Reduces Delirium

OBJECTIVES Postoperative delirium (POD) is a serious complication after cardiac surgery. Use of dexmedetomidine infusion to prevent delirium is controversial. We hypothesized that dexmedetomidine sedation after cardiac surgery would reduce the incidence of POD.METHODOLOGY After the approval from institutional ethics review board and informed consent, a comparative cross sectional study was conducted in 100 patients scheduled for cardiac surgery. Patients suffering from consequential psychological issues, delirium, and grievous dementia were excluded. Delirium was evaluated by confusion assessment method for ICU (CAM-ICU). Normality and homogenity of data were analyzed using Kolmogorov-Sminorv and saphiro wilk. The factors related to delirum status were analyzed using Logistic Regression.RESULTSThe mean age among propofol group was 55.14+9.6 while among Dexmedetomidine was 55.96+12.1. POD was present in 24 of 50 (48%) and 4 of 50 (8.%) patients in propofol and dexmedetomidine groups, respectively. variables which had significance values &lt;0.05 were patient age (0.000), associated disease (p&lt;-0.003). In regards to other variables like patient gender (p value: 0.660), pre-operative medication (p value: -0.090), different type of surgery (p value: -0.239), had no correlation with POD.CONCLUSIONIn comparison with propofol, dexmedetomidine postoperative sedation minimized the occurrence and abbreviated the time span of POD in patients who had to undergo cardiac surgery.

Efficacy of Intranasal Atomized Dexmedetomidine for Sedation in Surgical Removal of Impacted Mandibular Third Molars: A Prospective Study.

To assess the efficacy of dexmedetomidine atomized intranasally for sedation during surgical removal of impacted mandibular third molars. A prospective randomized trial was conducted on 25 anxious patients between the ages of 18 and 40 who had impacted the lower third molars. An intranasal atomization device was used to give the medication 30 minutes prior to the surgical procedure. The Ramsay sedation score and Observer's assessment of alertness/sedation score were used to assess intranasal sedation. The results of our study state that the sedative effect began to take effect between 30 and 45 minutes later and was nearly back to baseline by 105 minutes after the administration of intranasal dexmedetomidine. Intranasal delivery of 1.5mg/kg atomized dexmedetomidine for patients undergoing surgical removal of impacted mandibular third teeth is safe, feasible, and clinically efficient in daycare settings based on the sedation scores, and secondary variables which were assessed.

Breathe–squeeze: pharmacodynamics of a stimulus-free behavioural paradigm to track conscious states during sedation☆

BackgroundConscious states are typically inferred through responses to auditory tasks and noxious stimulation. We report the use of a stimulus-free behavioural paradigm to track state transitions in responsiveness during dexmedetomidine sedation. We hypothesised that estimated dexmedetomidine effect-site (Ce) concentrations would be higher at loss of responsiveness (LOR) compared with return of responsiveness (ROR), and both would be lower than comparable studies that used stimulus-based assessments. MethodsClosed-Loop Acoustic Stimulation during Sedation with Dexmedetomidine data were analysed for secondary analysis. Fourteen healthy volunteers were asked to perform the breathe–squeeze task of gripping a dynamometer when inspiring and releasing it when expiring. LOR was defined as five inspirations without accompanied squeezes; ROR was defined as the return of five inspirations accompanied by squeezes. Brain states were monitored using 64-channel EEG. Dexmedetomidine was administered as a target-controlled infusion, with Ce estimated from a pharmacokinetic model. ResultsCounter to our hypothesis, mean estimated dexmedetomidine Ce was lower at LOR (0.92 ng ml−1; 95% confidence interval: 0.69–1.15) than at ROR (1.43 ng ml−1; 95% confidence interval: 1.27–1.58) (paired t-test; P=0.002). LOR was characterised by progressively increasing fronto-occipital EEG power in the 0.5–8 Hz band and loss of occipital alpha (8–12 Hz) and global beta (16–30 Hz) power. These EEG changes reverted at ROR. ConclusionsThe breathe–squeeze task can effectively track changes in responsiveness during sedation without external stimuli and might be more sensitive to state changes than stimulus-based tasks. It should be considered when perturbation of brain states is undesirable. Clinical trial registrationNCT04206059.

A comprehensive overview of clinical research on dexmedetomidine in the past 2decades: A bibliometric analysis.

Introduction: Dexmedetomidine is a potent, highly selective α-2 adrenoceptor agonist with sedative, analgesic, anxiolytic, and opioid-sparing properties. A large number of dexmedetomidine-related publications have sprung out in the last 2decades. However, no bibliometric analysis for clinical research on dexmedetomidine has been published to analyze hot spots, trends, and frontiers in this field. Methods: The clinical articles and reviews related to dexmedetomidine, published from 2002 to 2021 in the Web of Science Core Collection, were retrieved on 19 May 2022, using relevant search terms. VOSviewer and CiteSpace were used to conduct this bibliometric study. Results: The results showed that a total of 2,299 publications were retrieved from 656 academic journals with 48,549 co-cited references by 2,335 institutions from 65 countries/regions. The United States had the most publications among all the countries (n = 870, 37.8%) and the Harvard University contributed the most among all institutions (n = 57, 2.48%). The most productive academic journal on dexmedetomidine was Pediatric Anesthesia and the first co-cited journal was Anesthesiology. Mika Scheinin is the most productive author and Pratik P Pandharipande is the most co-cited author. Co-cited reference analysis and keyword analysis illustrated hot spots in the dexmedetomidine field including pharmacokinetics and pharmacodynamics, intensive care unit sedation and outcome, pain management and nerve block, and premedication and use in children. The effect of dexmedetomidine sedation on the outcomes of critically ill patients, the analgesic effect of dexmedetomidine, and its organ protective property are the frontiers in future research. Conclusion: This bibliometric analysis provided us with concise information about the development trend and provided an important reference for researchers to guide future research.

Rapid emergence from dexmedetomidine sedation in Sprague Dawley rats by repurposing an α2-adrenergic receptor competitive antagonist in combination with caffeine

BackgroundThe α2 adrenergic receptor agonist dexmedetomidine is an important intravenous sedative with analgesic properties. Currently available dexmedetomidine reversal agents, like the α2-receptor antagonist atipamezole, cause serious adverse effects at the large dosages required for effective reversal; they are not used clinically. Without reversal agents, emergence times from dexmedetomidine sedation are slow. In this study we tested the ability of low-dose atipamezole, in combination with caffeine, to reverse dexmedetomidine sedation. The low dose of atipamezole employed should not be associated with unwanted effects.MethodsTwo different sedation protocols were employed. In the first protocol, a bolus of dexmedetomidine was rapidly applied and the drug was allowed to equilibrate for 10 min before rats received either saline (as control) or low-dose atipamezole with caffeine. Following this procedure, rats were placed on their backs. Emergence from sedation was the time for rats to recover their righting reflex and stand with 4 paws on the floor. A second sedation protocol simulated a pediatric magnetic resonance imaging (MRI) scan. Adult rats were sedated with dexmedetomidine for one hour followed by 30 min with both dexmedetomidine and propofol. At the end of 90 min, rats received either saline (control) or a combination of low-dose atipamezole, and caffeine. Recovery of the righting reflex was used as a proxy for emergence from sedation.ResultsEmergence from sedation, the time for rats to recover their righting reflex, decreased by ~ 90% when using an atipamezole dose ~ 20 fold lower than manufacturer’s recommendation, supplemented with caffeine. Using an atipamezole dose ~ tenfold lower than recommended, with caffeine, emergence times decreased by ~ 97%. A different stimulant, forskolin, when tested, was as effective as caffeine. For the MRI simulation, emergence times were decreased by ~ 93% by low-dose atipamezole with caffeine.ConclusionsLow dose atipamezole with caffeine was effective at reversing dexmedetomidine sedation. Emergence was rapid and the rats regained not only their righting reflex but also their balance and their ability to carry out complex behaviors. These findings suggest that the combination of low dose atipamezole with caffeine may permit rapid clinical reversal of dexmedetomidine without unwanted effects.

Relationship between the patient state index and sedation scale during dexmedetomidine sedation during spinal anesthesia

Background &amp; Objectives: Dexmedetomidine, a highly selective α-2 adrenoceptor agonist, is a widely used sedative during spinal anesthesia. Indices devised using processed electroencephalographic monitors are useful for identifying the level of sedation without disturbing the patient. However, we lack studies on the relationship between the patient state index (PSI) and dexmedetomidine sedation. We investigated the relationship between the PSI and sedation scale during dexmedetomidine sedation in patients undergoing spinal anesthesia.&#x0D; Methodology: This study entailed a review of the anesthetic records of patients who underwent dexmedetomidine sedation under SEDLine™ monitoring. After intrathecal injection, dexmedetomidine 1 µg/kg was injected intravenously over 10 min, followed by maintenance infusion at 0.4 µg/kg/h for 50 min. The PSI, mean blood pressure, heart rate, and oxygen saturation were recorded at regular intervals. The patients’ ‘Observer’s Assessment of Alertness/Sedation’ (OAA/S) scores were measured repeatedly until deep sedation (OAA/S ≤ 2) was achieved. The Spearman test was used to evaluate the correlation between the PSI value and OAA/S score. The cut-off PSI value for identifying OAA/S scores ≤ 2 was calculated using receiver operating characteristic curve analysis.&#x0D; Results: The PSI values corresponding to OAA/S scores of 5, 4, 3, 2, and 1 during dexmedetomidine sedation were 86.56 ± 10.45, 76.90 ± 13.99, 68.16 ± 16.18, 61.48 ± 15.26, and 55.67 ± 16.75, respectively (P &lt; 0.001). The Spearman correlation coefficient for the PSI and OAA/S scores was 0.6228 (P &lt; 0.001). The cut-off value of PSI for OAA/S scores ≤ 2 was 76. The mean blood pressure and heart rate decreased significantly compared to baseline and 60 min after continuous dexmedetomidine infusion (P &lt; 0.001).&#x0D; Conclusion: The patient state index decreased with the progression of dexmedetomidine sedation. Patient state index assessment could prove useful for evaluating the depth of sedation without distressing the patients.&#x0D; Abbreviations: BIS: Bispectral index; Dex: Dexmedetomidine; EEG: Electroencephalography; OAA/S: ‘Observer’s Assessment of Alertness/Sedation’; PSI: Patient state index; SA: Spinal anesthesia&#x0D; Key words: Conscious Sedation; Dexmedetomidine; Electroencephalography&#x0D; Citation: Lee KH. Relationship between the patient state index and sedation scale during dexmedetomidine sedation during spinal anesthesia. Anaesth. pain intensive care 2022;27(1):53−58.&#x0D; DOI: 10.35975/apic.v27i1.2117&#x0D; Received: July 28, 2022; Reviewed: October 26, 2022; Accepted: October 26, 2022

Nurse-led dexmedetomidine sedation for magnetic resonance imaging in children: a 6-year quality improvement project.

We aimed to safely introduce dexmedetomidine into a nurse-led sedation service for magnetic resonance imaging in children. Secondary aims were to increase the number of children eligible for sedation and to increase the actual number of children having sedation performed by our nurse sedation team. We analysed 1768 consecutive intravenous and 219 intranasal dexmedetomidine sedation episodes in infants, children and adolescents having magnetic resonance imaging scans between March 2016 and March 2022. The overall sedation success rate was 98.4%, with a 98.9% success rate for intravenous dexmedetomidine and a 95.0% success rate for intranasal dexmedetomidine. The incidence of scan interruption during intravenous and intranasal dexmedetomidine sedation was 8.8% and 21.9%, respectively. We conclude that paediatric sedation with dexmedetomidine for magnetic resonance scanning is safe and successful.

Nociception associated with pain/distress in young children sedated for dental treatment: a clinical study with objective and subjective measures.

To evaluate the association between children's pain/distress levels and patient characteristics (age, sex, history of dental pain), sedation type (level of sedation, sedative regimen), nociception and pain intensity reported by the parents in sedated children undergoing minimally invasive dental treatment. This clinical study evaluated secondary outcomes of an RCT that evaluated the efficacy of dexmedetomidine sedation with or without ketamine. Only children who had nociception levels recorded using the Analgesia Nociception Index (ANI) were included (0-100; 0 = highest nociception). FLACC scale (Face, Legs, Activity, Cry and Consolability) was used to assess children's pain/distress (0-10; 0 = no pain/distress). Parental proxy report of the child's pain intensity during the treatment was performed using the Visual Analogue Scale (VAS; 0-100; 0 = no pain). The association between ANI, children's age and sex, dental pain history, sedation level, sedative regimen, and VAS with the FLACC was verified using the generalised estimation equation analysis (alpha 0.05). Participants were 31 children (51.6% boys) and their parents (90.3% mothers). Median FLACC was 3.3 (25th-75th percentiles 1.7-8.2), ANI 80.9 (74.7-85.8), and VAS 10 (1-23). FLACC associated with ANI (OR 0.96; 95% CI 0.93-0.99; p = 0.02), moderate sedation (0.13; 0.03-0.50; p = 0.003), and VAS (1.05; 1.01-1.10; p = 0.01). Pain/distress was generally low and more prominent with minimal (versus moderate) sedation and higher nociception.

Pharmacodynamics of a stimulus-free behavioural paradigm to track conscious states during sedation with dexmedetomidine

Sedatives are powerful tools to study consciousness, allowing investigators to manipulate brain states and associated neurophysiological markers. Conscious states are typically inferred through responses to external stimuli such as auditory tasks and noxious stimulation. The use of an auditory task to probe loss of responsiveness (LOR) during dexmedetomidine sedation previously yielded a mean (standard deviation [sd]) effect-site concentration (Ce) of 2.06 (0.66) ng ml–1 at LOR.1 Here, we report a stimulus-free behavioural paradigm to assess conscious states during titration of dexmedetomidine.

Graph approaches for analysis of brain connectivity during dexmedetomidine sedation

Sedation is commonly used to relieve fear and anxiety during procedures. Dexmedetomidine (DEX), approved by the US Food and Drug Administration in 1999 for short-term sedation, is a selective alpha2-adrenoreceptor agonist. The use of DEX is increasing due to minimal respiratory depression and easy and quick awakening from sedation. Its sedative mechanisms are suggested to be related to changes in the interaction between brain regions. In this study, we used graph theory to investigate whether the altered network connection is associated with sedation. Electroencephalogram (EEG) recordings of 32 channels were acquired during awake and DEX-induced sedation for 20 participants. We extracted EEG epochs from the awake and the DEX sedation state. Using the graph theory, we compared the changes in the network connection parameters with the awake state. We observed that the slopes in 1/f dynamics, which indicate overall brain network characteristics, were greater during DEX-induced sedation compared to the awake state, suggesting a transition towards a random network behavior. In addition, network connections from the perspective of information processing were significantly disturbed in the alpha frequency band, unlike other frequency bands augmenting network connections. The alpha frequency band plays a prominent role in the function and interaction of cognitive activities. These results collectively indicate that changes in the brain network critical to cognition during DEX administration may also be related to the mechanism of sedation.

Comment on "Dexmedetomidine sedation for a dental extraction in a patient with known difficult airway".

Comment on "Dexmedetomidine sedation for a dental extraction in a patient with known difficult airway".

Феназепам® и Дексмедетомидин при плановых чрескожных коронарных вмешательствах. Сравнительный анализ

INTRODUCTION: Intraprocedural analgosedation in planned percutaneous coronary interventions is a priority method of anesthesia, since it provides comfort for patient in comparison with when it is absent; it leads to a fast recovery of patients and reduction of the incidence of complications in comparison with the general anesthesia. The question of the optimal sedation method is still open. AIM: To carry out a comparative analysis of sedation with Phenazepam® and Dexmedetomidine in planned percutaneous coronary interventions in patients with stable coronary heart disease. MATERIALS AND METHODS: A prospective randomized study was conducted from September 2021 to January 2022. The study included patients with stable ischemic heart disease (serum troponin T level less than 0.32 ng/ml; absence of anginous pain at the beginning of X-ray endovascular intervention), who had planned percutaneous coronary intervention. The Phenazepam® sedation group included 40 patients, including 30.0% (n = 12) women and 70.0% (n = 28) men. 40 patients were included in the Dexmedetomidine sedation group: 30.0% (n = 12) women, 70.0% (n = 28) men. RESULTS: There was a statistically significant (p &lt; 0.001) reduction of blood pressure and heart rate in patients in the group of sedation with Dexmedetomidine at the stage of stenting of the coronary artery, compared with analogous parameters in the group of sedation with Phenazepam®. Patients in the group of sedation with Dexmedetomidine developed chest pain at the stage of coronary artery stenting reliably 3.13 times less often (p = 0.024) than patients of the group of sedation with Phenazepam® (OR: 0.32; 95% CI: 0.13–0.80). With use of Dexmedetomidine, relief of anginal pain with narcotic analgesics was required 20 times less often (p &lt; 0.001) than with Phenazepam® (OR: 0.05; 95% CI: 0.01–0.38). One can confidently speak about the superiority and safety of analgosedation with Dexmedetomidine in planned percutaneous coronary interventions over sedation with Phenazepam®. CONCLUSIONS: Dexmedetomidine provides deeper sedation and sufficient pain relief in patients in planned percutaneous coronary interventions than Phenazepam®. At the same time, Dexmedetomidine has a more pronounced hypotensive and a negative chronotropic effect.