Sedative, haemodynamic and respiratory effects of dexmedetomidine in children undergoing magnetic resonance imaging examination: preliminary results

Comparison of the Efficacy of Midazolam and Dexmedetomidine As Sedative Agents in Third Molar Surgery

Introduction Minor dental and oral surgical procedures have been made comfortable with the rise in the use of daycare sedatives. Of these sedatives, midazolam is deemed a common sedative used for minor oral surgical procedures. Newer and safer sedatives such as dexmedetomidine have certain properties that may prove more efficient in oral surgical procedures. Third molar surgery is one of the most common minor oral surgical procedures performed in dentistry. Thus, this study aims to compare the efficacy of midazolam and dexmedetomidine as sedative agents in third molar surgery. Materials and methods Sixty young adult patients free from other comorbidities were included in the study with ages ranging between 18 and 50 years. The samples were matched for the difficulty of impacted teeth and randomly distributed among the groups. Groups were administered the respective sedative drugs midazolam and dexmedetomidine and their effects were observed through the Observer's Assessment of Alertness/Sedation scale. The intraoperative vitals and sedation effects were checked every 15 minutes. Statistical analysis was done using IBM SPSS Statistics for Windows, Version 22 (Released 2013; IBM Corp., Armonk, New York, United States). Independent samples t-test and analysis of variance were the statistical tests employed to analyze the obtained data with p<0.05 considered as statistically significant. Results The depth of sedation has been both subjectively and objectively assessed and had no significant difference among the groups. The intra-operative heart rate assessment proved a more efficient reduction of pulse rate in the dexmedetomidine group as compared with the midazolam group. However, it was not statistically significant (p=0.121). The mean diastolic blood pressure showed a statistically significant difference between the groups with dexmedetomidine having lower blood diastolic pressure compared to midazolam (p=0.004). Quick arousal was witnessed in the dexmedetomidine group. Conclusion It can be concluded from the study that both dexmedetomidine and midazolam were equally effective as sedative agents for third molar surgery. However, the nature of cardio-protection, anti-sialagogue, and analgesic properties of dexmedetomidine can prove helpful, especially in minor oral surgical procedures like third molar surgery and it is recommended.

Efficacy and safety of dexmedetomidine in maintaining hemodynamic stability in pediatric cardiac surgery: a systematic review and meta-analysis

OBJECTIVES

Dexmedetomidine (DEX) is a highly selective alpha-2 adrenergic receptor agonist, which is the main sedative in the intensive care unit. This study aims to investigate the effectiveness and adverse events of DEX in maintaining hemodynamic stability in pediatric cardiac surgery.

SOURCES

Databases such as PubMed, Cochrane, Web of Science, WANFANG STATA and China National Knowledge Infrastructure were searched for articles about the application of DEX in maintaining hemodynamic stability during and after pediatric cardiac surgery up to 18th Feb. 2021. Only randomized controlled trials were included and random-effects model meta-analysis was applied to calculate the standardized mean deviation (SMD), odds ratio (OR) and 95% confidence interval (CI).

SUMMARY OF THE FINDINGS

Fifteen articles were included for this meta-analysis, and 9 articles for qualitative analysis. The results showed that preoperative prophylaxis and postoperative recovery of DEX in pediatric patients undergoing cardiac surgery were effective in maintaining systolic blood pressure (SBP), mean arterial pressure (MAP), diastolic blood pressure (DBP) and reducing heart rate (HR) (SBP: SMD = -0.35,95% CI: -0.72, 0.01; MAP: SMD = -0.83, 95% CI: -1.87,0.21; DBP: SMD = -0.79,95% CI: -1.66,0.08; HR: SMD = -1.71,95% CI: -2.29, -1.13). In addition, the frequency of Junctional Ectopic Tachycardia in the DEX treatment group was lower than that in the placebo group.

CONCLUSIONS

The application of DEX for preoperative prophylaxis and postoperative recovery in pediatric cardiac surgery patients are effective in maintaining hemodynamic stability, and the clinical dose of DEX is not significantly related to the occurrence of pediatric adverse events which may be related to individual differences.

ONE-LUNG VENTILATION PATIENTS: CLINICAL CONTEXT OF ADMINISTRATION OF DIFFERENT DOSES OF DEXMEDETOMIDINE

Background

Open and endoscopic thoracic surgeries improve surgical exposure by One-lung ventilation (OLV). The aim of this study was to investigate the effects of different doses of dexmedetomidine on inflammatory response, oxidative stress, cerebral tissue oxygen saturation (SctO2) and intrapulmonary shunt in patients undergoing one-lung ventilation (OLV).

Methods

Seventy-five patients undergoing open pulmonary lobectomy in our hospital from January 2016 to December 2017 were enrolled and randomly divided into high-dose dexmedetomidine group (group D1, 1 mg/kg, n=25), low-dose dexmedetomidine group (group D2, 0.5 mg/kg, n=25) and control group (group C, n=25). Then, arterial blood and internal jugular venous blood were taken before anesthesia induction (T0) and at 15 min after twolung ventilation (T1) and 5 min (T2) and 30 min (T3) after OLV for later use. Next, the changes in hemodynamic parameters [mean arterial pressure (MAP), heart rate (HR) and pulse oxygen saturation (SpO2)] of patients were observed in each group. Enzyme-linked immunosorbent assay (ELISA) was carried out to detect serum inflammatory factors such as interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) and oxidative stress indicators [superoxide dismutase (SOD) and malondialdehyde (MDA)]. The changes in SctO2, arterial partial pressure of oxygen (PaO2) and intrapulmonary shunt Qs/Qt (a measurement of pulmonary shunt: right-to-left shunt fraction) were observed. Additionally, the changes in lung function indicators like lung dynamic compliance (Cdyn) and airway peak pressure (P_peak) were determined.

Results

There were no statistically significant differences in the MAP, HR and SpO2 among three groups at each observation time point (P>0.05). At T2 and T3, the levels of serum IL-6, TNF-α and IL-8 were obviously decreased in group D1 and D2 compared with those in group C (P<0.05), and the decreases in group D1 were overtly larger than those in group D2, and the decreases at T3 were markedly greater than those at T2 (P<0.05). In comparison with group C, group D1 and D2 had notably reduced levels of serum reactive oxygen species (ROS) and MDA (P<0.05) and remarkably increased SOD content (P<0.05) at T2 and T3, and the effects were markedly better in group D1 than those in group D2. Besides, they were significantly superior at T3 to those at T2 (P<0.05). The SctO2 in group D1 and D2 was evidently lowered at T2 and T3 compared with that at T0, and the decrease in group D1 was distinctly smaller than that in group D2 (P<0.05). The Qs/Qt was significantly lower in group D1 and D2 than that in group C at T2 and T3 (P<0.05), while the PaO2 content was notably raised (P<0.05), and the decrease and increase were significantly larger in group D1 than those in group D2, and they were obviously greater at T3 to those at T2 (P<0.05). At T0 and T1, no significant differences were detected in the Cdyn, Pplat and Ppeak among three groups. At T2 and T3, the Cdyn was significantly elevated, while the Pplat and Ppeak overtly declined (P<0.05), and group D1 had greater changes in comparison with group D2, and the changes were obviously more evident at T3 to those at T2 (P<0.05).

Conclusions

Dexmedetomidine effectively ameliorates inflammatory response and oxidative stress, lowers oxygenation, Qs/Qt and the decrease in SctO2 and improves lung function during OLV, with good efficacy.

Effectiveness of Chloral Hydrate on Brain MRI in Children with Developmental Delay/Intellectual Disability Comparing with Normal Intelligence: Single Tertiary Center Experience

Neurodiagnostic investigation requirements are expanding for diagnostic and therapeutic purposes in children, especially in those with developmental delay/intellectual disability (DD/ID). Thus, determination of optimal sedatives to achieve successful sedation and immobility without further neurological compromise is important in children with DD/ID. The purpose of this study is to assess the effectiveness and adverse reactions of chloral hydrate (CH) for brain magnetic resonance imaging (B-MRI) in children with DD/ID compared to those with normal intelligence (NI). We performed a retrospective chart review of children aged from 1 day to 12 years who required elective sedation using CH for B-MRI. About 730 cases (415 with DD/ID and 315 with NI) of CH sedation were conducted for B-MRI. Children with DD/ID showed a higher failure rate (22%) than did those with NI (6%); additional CH and prolonged sedation time were required. There was no difference in incidence of adverse reactions between DD/ID and NI groups (p = 0.338). Older or heavier children with DD/ID (p = 0.036 and p = 0.013, respectively), as well as those diagnosed with epilepsy or neuropsychiatric disorders showed higher risk of sedation failure (p < 0.001 for each). In conclusion, CH was a suboptimal sedative drug for children with DD/ID compared with those with NI. Other alternative or supplementary sedatives should be taken into consideration especially for those vulnerable groups.

Effects of dexmedetomidine sedation for magnetic resonance imaging in children: a systematic review and meta-analysis

PURPOSE

Pediatric sedation is commonly required to obtain high-quality images in magnetic resonance imaging (MRI). We performed a systematic review and meta-analysis to assess the effects of dexmedetomidine sedation for MRI in children.

METHODS

A systematic review was conducted to find all randomized controlled trials concerning dexmedetomidine sedation for MRI in children. We searched databases using the Ovid platform in the Cochrane Controlled Trials Register, MEDLINE, and EMBASE. This study was registered in the PROSPERO database: CRD42020198368.

RESULTS

Seven studies and 753 participants were included. Dexmedetomidine sedation showed a significantly delayed onset time [weighted mean differences (WMD) = 8.13 min, 95% confidence interval (CI) 4.64 to 11.63, I² = 98%] and recovery time (WMD = 5.22 min, 95% CI 0.35 to 10.09, I² = 92%) compared to propofol, ketamine, and midazolam sedation. There was no difference in quality of sedation [risk ratio (RR) = 1.25, 95% CI 0.92 to 1.69, I² = 89%], or incidence of sedation failure (RR = 1.39, 95% CI 0.53 to 3.66, I² = 83%) between groups. Although a significantly decreased heart rate (WMD = - 17.34 beats/minute, 95% CI - 22.42 to - 12.26, I² = 96%) was observed, bradycardia that required treatment was not increased (RR = 8.00, 95% CI 1.02 to 62.64, I² = 0%). Dexmedetomidine sedation had a lower incidence of desaturation events (RR = 0.42, 95% CI 0.20 to 0.86, I² = 4%). However, there was no difference in incidence of postoperative vomiting (RR = 0.42, 95% CI 0.15 to 1.17, I² = 17%) between groups.

CONCLUSIONS

Dexmedetomidine sedation provided a similar sedation quality with a reduced incidence of desaturation events. However, the delayed onset and recovery times were drawbacks. The clinical significance of bradycardia is considered to be low. GRADE assessment revealed the quality of the evidence in this meta-analysis ranged from very low to moderate.

Determination of the ED95 of a single bolus dose of dexmedetomidine for adequate sedation in obese or nonobese children and adolescents

BACKGROUND

With the increasing prevalence of children who are overweight and with obesity, anaesthesiologists must determine the optimal dosing of medications given the altered pharmacokinetics and pharmacodynamics in this population. We therefore determined the single dose of dexmedetomidine that provided sufficient sedation in 95% (ED₉₅) of children with and without obesity as measured by a minimum Ramsay sedation score (RSS) of 4.

METHODS

Forty children with obesity (BMI >95th percentile for age and gender) and 40 children with normal weight (BMI 25th-84th percentile), aged 3-17 yr, ASA physical status 1-2, undergoing elective surgery, were recruited. The biased coin design was used to determine the target dose. Positive responses were defined as achievement of adequate sedation (RSS ≥4). The initial dose for both groups was dexmedetomidine 0.3 μg kg^-1 i.v. infusion for 10 min. An increment or decrement of 0.1 μg kg^-1 was used depending on the responses. Isotonic regression and bootstrapping methods were used to determine the ED₉₅ and 95% confidence intervals (CIs), respectively.

RESULTS

The ED₉₅ of dexmedetomidine for adequate sedation in children with obesity was 0.75 μg kg^-1 with 95% CI of 0.638-0.780 μg kg^-1, overlapping the CI of the ED₉₅ estimate of 0.74 μg kg^-1 (95% CI: 0.598-0.779 μg kg^-1) for their normal-weight peers.

CONCLUSIONS

The ED₉₅ values of dexmedetomidine administered over 10 min were 0.75 and 0.74 μg kg^-1 in paediatric subjects with and without obesity, respectively, based on total body weight.

CLINICAL TRIAL REGISTRATION

ChiCTR1800014266.

A Prospective Randomized Controlled Trial Using Propofol or Dexmedetomidine for Conscious Sedation in Pediatric Patients Undergoing Sclerotherapy

Aim:

Sodium tetradecyl sulfate (STS) sclerotherapy in pediatric patients is usually undertaken under sedation inside digital subtraction angiography (DSA) suite. These patients are day-care patients and need adequate sedation for small duration. We performed this study to compare propofol and dexmedetomidine as sedative agents in these patients.

Materials and Methods:

Seventy American Society of Anesthesiologists (ASA) physical status I patients scheduled to undergo sclerotherapy for low-flow venous malformations under sedation were randomized to be administered either dexmedetomidine (Group D) or propofol (Group P). In Group D, initially 2 µg/kg of dexmedetomidine was administered over 10min (or till attainment of a Ramsay sedation score [RSS] of 5), followed by an infusion at the rate of 0.3 µg/kg/h. In Group P, propofol 1mg/kg bolus followed by an infusion at 100 µg/kg/min was administered, titrated to an RSS of 5. We measured intraoperative heart rate, blood pressure, respiratory rate, duration of procedure, and incidence of arterial desaturation, bradycardia, and respiratory depression in the two groups.

Results:

All the patients in both groups completed the procedure. The mean anesthesia time was significantly longer in Group D. Intraoperative heart rates remained comparable in the two groups, whereas systolic and diastolic BP were significantly higher in Group D throughout the procedure. No patient in Group D experienced arterial desaturation, whereas five patients in Group P reported a SpO₂ of <90%.

Conclusion:

Both propofol and dexmedetomidine can be used for administering sedation in pediatric patients undergoing sclerotherapy for superficial venous malformations in DSA suite. Although propofol provides a rapid onset and reduced duration of action, dexmedetomidine provides reduced episodes of arterial desaturation and respiratory depression.

The Effect of Midazolam and Dexmedetomidine Sedation on Block Characteristic Following Spinal Bupivacaine: A Randomized Comparative Study

Background:

Dexmedetomidine is widely used as an adjunct to general as well as regional anesthesia.

Aims:

This study was conducted to compare and evaluate the synergistic effect of single intravenous (i.v.) bolus dose of dexmedetomidine with midazolam on spinal block duration, analgesia, and sedation in patients undergoing infra-umbilical surgeries.

Settings and Design:

Prospective, randomized, comparative, and double-blinded study.

Materials and Methods:

One hundred patients between 18 and 60 years of age of American Society of Anesthesiologists physical status I and II posted for elective infra-umbilical surgery under subarachnoid block were randomly divided into two groups (Group D and Group M). Patients of Group D received i.v. dexmedetomidine 0.5 μg.kg⁻¹ and of Group M received i.v. midazolam 0.05 mg.kg⁻¹ as premedication 5 min before spinal anesthesia over 10 min. Vital parameters, Ramsay sedation score, level of sensory and motor block, recovery time for sensory blockade, postoperative numerical rating scale, time of requirement of the first dose of postoperative rescue analgesic, and duration of analgesia were recorded and analyzed.

Statistical Analysis:

Chi-square test, t-test, and analysis of variance test were applied to analyze data using SPSS package for Windows.

Results and Conclusion:

Premedication with single i.v. dexmedetomidine prolonged the duration and increased the maximum upper level of only sensory component of spinal anesthesia (6.42 ± 3.21 vs. 4.8 ± 1.21 thoracic segments higher than with midazolam sedation). This property can be beneficial in preventing undesirable prolongation of motor block and facilitating early ambulation in shorter duration of infra-umbilical surgeries. In addition, dexmedetomidine slowed the regression of sensory block and increased the time of the first request of analgesic.

A comparative evaluation of dexmedetomidine and midazolam in pediatric sedation: A meta-analysis of randomized controlled trials with trial sequential analysis

Background

The present study with trial sequential analysis (TSA) was conducted to evaluate comprehensively the efficacy and safety of dexmedetomidine and midazolam in pediatric sedation, and to investigate whether the outcomes achieved the required information size to draw the conclusions.

Methods

PubMed, Embase, and Cochrane Library were searched from inception to October 2019. All randomized controlled trials used dexmedetomidine and midazolam in pediatric sedation were enrolled. Sedative efficacy, postoperative analgesic effect, and incidence of emergence agitation were considered as the co‐primary outcomes. Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system was applied to rate the quality of evidences.

Results

We acquired data from 34 studies involving 2281 pediatric patients. The results indicated that administration of dexmedetomidine was associated with less incidence of emergence agitation (RR = 0.78, with 95% CI [0.65, 0.92]) and more satisfactory sedation at parental separation (RR = 0.31, with 95% CI [0.24, 0.41]) compared to midazolam, and the current sample sizes were sufficient with unnecessary further trials. Two groups did not differ significantly in sedation level at mask induction (RR = 0.86, with 95% CI [0.74, 1.00]). And using of dexmedetomidine was associated with less incidence of postoperative analgesic rescue (RR = 0.57, with 95% CI [0.35, 0.93]), but the number of patients was too few to achieve the required information size and to draw reliable conclusions. Premedication of dexmedetomidine was associated with significant less value of SBP, heart rate, increased incidence of bradycardia, and a lower rate of shivering. And there were no differences about onset of sedation and recovery time between two groups.

Conclusions

Given that more satisfactory sedation at separation from parents and less incidence of emergence agitation, dexmedetomidine is preferred for pediatric sedation. However, compared with midazolam, the superiority of dexmedetomidine in providing adequate sedation at mask induction and postoperative analgesic effects has not yet been defined.

Effectiveness of pediatric drug-induced sleep endoscopy for REM-predominant obstructive sleep apnea

STUDY OBJECTIVES

Because dexmedetomidine (DEX)-induced sedation mimics non-rapid eye movement (NREM) sleep, its utility in sedating children with REM-predominant disease is unclear. We sought to determine the effectiveness of pediatric drug-induced sleep endoscopy (DISE) using DEX and ketamine for children with REM-predominant OSA, specifically whether or not at least one site of obstruction could be identified.

METHODS

A retrospective case series of children without tonsillar hypertrophy undergoing DISE at a tertiary pediatric hospital from 10/2013 through 9/2015 who underwent subsequent surgery to address OSA with polysomnography (PSG) before and after.

RESULTS

We included 56 children, mean age 5.6±5.4 years, age range 0.1-17.4 years, mean BMI 20.3±7.4 kg/m2 (76±29 percentile). At least one site of obstruction was identified in all patients, regardless of REM- or NREM-predominance. The mean obstructive apnea-hypopnea index (oAHI) improved (12.6 ± 10.7 to 9.0 ± 14.0 events/h) in children with REM-predominant (P = 0.013) and NREM-predominant disease (21.3 ± 18.9 to 10.3 ± 16.2 events/h) (P = 0.008). The proportion of children with a postoperative oAHI < 5 was 53% and 55% for REM- and NREMpredominant OSA, respectively. Unlike children with NREM-predominant disease, children with REM-predominant disease had significant improvement in the mean saturation nadir (P < 0.001), total sleep time (P = 0.006), and sleep efficiency (P = 0.015).

CONCLUSIONS

For children with OSA without tonsillar hypertrophy, DISE using DEX/ketamine was useful to predict at least one site of obstruction, even for those with REM-predominant OSA. DISE-directed outcomes resulted in significant improvements in mean oAHI, total sleep time, sleep efficiency, saturation nadir, and the proportion with oAHI < 5, after surgery for some children with REM-predominant disease.

Incidence and risk factors of bradycardia in pediatric patients undergoing intranasal dexmedetomidine sedation

BACKGROUND

Dexmedetomidine is widely used for non-invasive pediatric procedural sedation. However, the hemodynamic effects of intravenous dexmedetomidine are a concern. There has been a growing interest in the application of intranasal dexmedetomidine as a sedative in children.

OBJECTIVE

To investigate the incidence of bradycardia in children undergoing intranasal dexmedetomidine sedation and to identify the associated risk factors.

METHODS

Data pertaining to pediatric patients who underwent intranasal dexmedetomidine sedation for non-invasive investigations at the Kunming Children's Hospital between October 2017 and August 2018 were retrospectively analyzed.

RESULTS

Out of 9984 children who qualified for inclusion, 228 children (2.3%) developed bradycardia. The incidence of bradycardia in the group that received additional dose of dexmedetomidine was higher than that in the group that did not receive additional dose (9.2% vs 16.7%; P = .003). The incidence of bradycardia in males was higher than that in females (2.6% vs 1.8%; P = .007). On multivariate logistic regression, only male gender showed an independent association with the occurrence of bradycardia (odds ratio 1.48; 95% confidence interval 1.11-1.97; P = .008).

CONCLUSIONS

The overall incidence of bradycardia in children after sole use of intranasal dexmedetomidine sedation was 2.3%. Male children showed a 1.48-fold higher risk of bradycardia. However, the blood pressure of the children who developed bradycardia was within the normal range. Simple wake-up can effectively manage bradycardia induced by intranasal dexmedetomidine sedation.

Volatiles or TIVA: Which is the standard of care for pediatric airway procedures? A pro-con discussion

Anesthesia for pediatric airway procedures constitutes a true art form that requires training and experience. Communication between anesthetist and surgeon to establish procedure goals is essential in determining the most appropriate anesthetic management. But does the mode of anesthesia have an impact? Traditionally, inhalational anesthesia was the most common anesthesia technique used during airway surgery. Introduction of agents used for total intravenous anesthesia (TIVA) such as propofol, short-acting opioids, midazolam, and dexmedetomidine has driven change in practice. Ongoing debates abound as to the advantages and disadvantages of volatile-based anesthesia versus TIVA. This pro-con discussion examines both volatiles and TIVA, from the perspective of effectiveness, safety, cost, and environmental impact, in an endeavor to justify which technique is the best specifically for pediatric airway procedures.

Efficacy of premedication with intranasal dexmedetomidine for removal of inhaled foreign bodies in children by flexible fiberoptic bronchoscopy: a randomized, double-blind, placebo-controlled clinical trial

Background

Tracheobronchial foreign body aspiration in children is a life-threatening, emergent situation. Currently, the use of fiberoptic bronchoscopy for removing foreign bodies is attracting increasing attention. Oxygen desaturation, body movement, laryngospasm, bronchospasm, and breath-holding are common adverse events during foreign body removal. Dexmedetomidine, as a highly selective α₂-adrenergic agonist, produces sedative and analgesic effects, and does not induce respiratory depression. We hypothesized that intranasal dexmedetomidine at 1 μg kg − 1 administered 25 min before anesthesia induction can reduce the incidence of adverse events during fiberoptic bronchoscopy under inhalation general anesthesia with sevoflurane.

Methods

In all, 40 preschool-aged children (6–48 months) with an American Society of Anesthesiologists physical status of I or II were randomly allocated to receive either intranasal dexmedetomidine at 1 μg·kg − 1 or normal saline at 0.01 ml kg^− 1 25 min before anesthesia induction. The primary outcome was the incidence of perioperative adverse events. Heart rate, respiratory rate, parent-child separation score, tolerance of the anesthetic mask, agitation score, consumption of sevoflurane, and recovery time were also recorded.

Results

Following pre-anesthesia treatment with either intranasal dexmedetomidine or saline, the incidences of laryngospasm (15% vs. 50%), breath-holding (10% vs. 40%), and coughing (5% vs. 30%) were significantly lower in patients given dexmedetomidine than those given saline. Patients who received intranasal dexmedetomidine had a lower parent–child separation score (P = 0.017), more satisfactory tolerance of the anesthetic mask (P = 0.027), and less consumption of sevoflurane (38.18 ± 14.95 vs. 48.03 ± 14.45 ml, P = 0.041). The frequency of postoperative agitation was significantly lower in patients given intranasal dexmedetomidine (P = 0.004), and the recovery time was similar in the two groups.

Conclusions

Intranasal dexmedetomidine 1 μg·kg^− 1, with its sedative and analgesic effects, reduced the incidences of laryngospasm, breath-holding, and coughing during fiberoptic bronchoscopy for FB removal. Moreover, it reduced postoperative agitation without a prolonged recovery time.

Trail registration

The study was registered with the Chinese Clinical Trial Registry (registration number: ChiCTR1800017273) on July 20, 2018.

Comparison of dexmedetomidine with propofol as sedatives for pediatric patients undergoing magnetic resonance imaging: A meta-analysis of randomized controlled trials with trial sequential analysis

Dexmedetomidine and propofol are commonly used sedative agents in pediatric patients undergoing magnetic resonance imaging (MRI). The present meta-analysis aimed to compare dexmedetomidine with propofol in pediatric patients undergoing MRI using trial sequential analysis (TSA). The PubMed, Cochrane Library and Web of Knowledge databases were systematically searched for entries up to August 2018 for potential randomized controlled trials comparing dexmedetomidine with propofol in pediatric patients undergoing MRI. Data were extracted by two independent authors and analyzed using Revman version 5.2 software. Six trials involving 415 pediatric patients were included in the final analysis. A shorter recovery time (P<0.01) and onset time of sedation were identified for propofol compared with dexmedetomidine (P<0.01); however, there were no significant differences in the duration of sedation (P=0.37). Furthermore, pediatric patients receiving propofol were discharged sooner than those receiving dexmedetomidine (P=0.02). The incidence of failed sedation did not significantly differ between the two groups (P=0.81). Propofol induced a lower incidence of 5-min (P=0.03) and 10-min Pediatric Anesthesia Emergence Delirium (P<0.01), but a higher incidence of desaturation (P<0.01). The duration of MRI was similar between the two groups (P=0.15). TSA indicated that the monitoring boundary was crossed by the cumulative z curve, providing supportive evidence for the shorter recovery time in the propofol group. Propofol is recommended for pediatric sedation during MRI, owing to shorter recovery time and onset of sedation time, as well as a faster discharge from hospital, and a lower incidence of PAED score >10, compared with dexmedetomidine. However, considering the possibility of desaturation, propofol should be used with caution.

Population Pharmacokinetics and Pharmacodynamics of Dexmedetomidine in Children Undergoing Ambulatory Surgery

BACKGROUND

Dexmedetomidine (DEX) is an α-2 adrenergic agonist with sedative and analgesic properties. Although not approved for pediatric use by the Food and Drug Administration, DEX is increasingly used in pediatric anesthesia and critical care. However, very limited information is available regarding the pharmacokinetics of DEX in children. The aim of this study was to investigate DEX pharmacokinetics and pharmacodynamics (PK-PD) in Mexican children 2-18 years of age who were undergoing outpatient surgical procedures.

METHODS

Thirty children 2-18 years of age with American Society of Anesthesiologists physical status score of I/II were enrolled in this study. DEX (0.7 μg/kg) was administered as a single-dose intravenous infusion. Venous blood samples were collected, and plasma DEX concentrations were analyzed with a combination of high-performance liquid chromatography and electrospray ionization-tandem mass spectrometry. Population PK-PD models were constructed using the Monolix program.

RESULTS

A 2-compartment model adequately described the concentration-time relationship. The parameters were standardized for a body weight of 70 kg by using an allometric model. Population parameters estimates were as follows: mean (between-subject variability): clearance (Cl) (L/h × 70 kg) = 20.8 (27%); central volume of distribution (V1) (L × 70 kg) = 21.9 (20%); peripheral volume of distribution (V2) (L × 70 kg) = 81.2 (21%); and intercompartmental clearance (Q) (L/h × 70 kg) = 75.8 (25%). The PK-PD model predicted a maximum mean arterial blood pressure reduction of 45% with an IC50 of 0.501 ng/ml, and a maximum heart rate reduction of 28.9% with an IC50 of 0.552 ng/ml.

CONCLUSIONS

Our results suggest that in Mexican children 2-18 years of age with American Society of Anesthesiologists score of I/II, the DEX dose should be adjusted in accordance with lower DEX clearance.

A Comparison of Safety and Efficacy of Dexmedetomidine and Propofol in Children with Autism and Autism Spectrum Disorders Undergoing Magnetic Resonance Imaging

Children with autism and autism spectrum disorders have a high incidence of neurologic comorbidities. Consequently, evaluation with magnetic resonance imaging (MRI) is deemed necessary. Sedating these patients poses several challenges. This retrospective study compared the efficacy and safety of dexmedetomidine to propofol in sedating autistic patients undergoing MRI. There were 56 patients in the dexmedetomidine group and 49 in the propofol group. All of the patients successfully completed the procedure. Recovery and discharge times were significantly lower in the propofol group, while the dexmedetomidine group maintained more stable hemodynamics. Both propofol and dexmedetomidine proved to be adequate and safe medications in the sedation of autistic children undergoing MRI.

To Evaluate the Efficiency of Dexmedetomidine in Atomized Intranasal form for Sedation in Minor Oral Surgical Procedures

Aim

This study aims to evaluate the efficiency of dexmedetomidine in atomized intranasal form for sedation in minor oral surgical procedures.

Materials and Methods

A total 25 patients fitting the inclusion and exclusion criteria were selected from the outpatient Department of Oral and Maxillofacial Surgery, Saraswati Dental College and Hospital, Lucknow. The drug was administered intranasally half an hour before the surgical procedure. The volume of drug used was recorded. The readings of all the parameters of sedation began 30 min after the drug had been administered. Intranasal sedation status was assessed by Ramsay sedation score and observer's assessment of alertness/sedation scales, every 15 min throughout the procedure.

Results

The primary outcome variable in this study is depth of sedation produced by intranasally administered dexmedetomidine. Secondary variables included respiratory rate, blood pressure (BP), heart rate (HR), and oxygen saturation (SpO₂). The statistical software used was SPSS 20.0 for Windows (SPSS, Chicago, IL, USA). Data were expressed as mean and standard deviation or number (percentages). Sedation and behavior scores were analyzed by proportions. Hemodynamic variables including HR, SpO₂, and BP and respiratory rate were analyzed by repeated measures ANOVA. When a significant result was obtained, the Tukey test was applied for post hoc pairwise comparisons. P < 0.05 was considered as statistically significant. All the parameters were recorded at a set interval of time.

Conclusion

In conclusion, intranasal administration of 1.5 mg/kg atomized dexmedetomidine was clinically effective, convenient, and safe for the sedation of patients undergoing minor oral surgical procedures.

A non-randomized controlled study of total intravenous anesthesia regimens for magnetic resonance imaging studies in children

BACKGROUND AND AIMS

We studied the efficacy and safety of different total intravenous anesthesia used for pediatric magnetic resonance imaging (MRI).

MATERIAL AND METHODS

Children of 1-7 years age (n = 88), undergoing MRI received a loading dose of dexmedetomidine 1 μg/kg over 10 min, ketamine 1 mg/kg, and propofol 1 mg/kg in sequence. University of Michigan Sedation Scale (UMSS) of 3 was considered an acceptable level for starting the scan. Rescue ketamine 0.25-0.5 mg/kg was given if UMSS remained <3. After the loading dose of drugs, some children attained UMSS = 4 or progressive decline in heart rate, therefore, did not receive any infusion. The rest received either dexmedetomidine (0.7 μg/kg/h) (n = 35) or propofol (3 mg/kg/h) (n = 38) infusion for maintenance. Ketamine 0.25 mg/kg was used as rescue. Sedation failure was considered if either there was inability to complete the scan at the pre-set infusion rate, or there was need for >3 ketamine boluses or serious adverse events occurred. Statistical Package for Social Sciences 20 was used for analysis.

RESULTS

Initiation of scan was 100% successful with median induction time of 10 min. Maintenance of sedation was successful in 100% with dexmedetomidine and 97.4% with propofol infusion. Recovery time (25 min v/s 30 min), discharge time (35 min v/s 60 min), and total care duration (80 min v/s 105 min) were significantly less with propofol as compared to dexmedetomidine (P = 0.002, 0.000, and 0.000, respectively). There were no significant adverse events observed.

CONCLUSION

Dexmedetomidine 1μg/kg, ketamine 1 mg/kg, and propofol 1 mg/kg provide good conditions for initiation of MRI. Although dexmedetomidine at 0.7μg/kg/h and propofol at 3 mg/kg/h are safe and effective for maintenance, propofol provides faster recovery.

Dexmedetomidine: present and future directions

Dexmedetomidine is a potent, highly selective α-2 adrenoceptor agonist, with sedative, analgesic, anxiolytic, sympatholytic, and opioid-sparing properties. Dexmedetomidine induces a unique sedative response, which shows an easy transition from sleep to wakefulness, thus allowing a patient to be cooperative and communicative when stimulated. Dexmedetomidine may produce less delirium than other sedatives or even prevent delirium. The analgesic effect of dexmedetomidine is not strong; however, it can be administered as a useful analgesic adjuvant. As an anesthetic adjuvant, dexmedetomidine decreases the need for opioids, inhalational anesthetics, and intravenous anesthetics. The sympatholytic effect of dexmedetomidine may provide stable hemodynamics during the perioperative period. Dexmedetomidine-induced cooperative sedation with minimal respiratory depression provides safe and acceptable conditions during neurosurgical procedures in awake patients and awake fiberoptic intubation. Despite the lack of pediatric labelling, dexmedetomidine has been widely studied for pediatric use in various applications. Most adverse events associated with dexmedetomidine occur during or shortly after a loading infusion. There are some case reports of dexmedetomidine-related cardiac arrest following severe bradycardia. Some extended applications of dexmedetomidine discussed in this review are promising, but still limited, and further research is required. The pharmacological properties and possible adverse effects of dexmedetomidine should be well understood by the anesthesiologist prior to use. Moreover, it is necessary to select patients carefully and to determine the appropriate dosage of dexmedetomidine to ensure patient safety.

Effects of dexmedetomidine infusion during spinal anesthesia on hemodynamics and sedation

Background: We evaluated the effects of intravenous dexmedetomidine during spinal anesthesia on hemodynamics, respiratory rate, oxygen saturation, sedpain, and compared them with those of saline infusion. Sixty American Society of Anesthesiologists physical status I and II cases were randomly divided into two groups. Patients were connected to the monitor after premedication, and spinal anesthesia was administered. Sensory and motor blockades were assessed using pinprick test and Bromage scale, respectively. Group I received dexmedetomidine infusion and Group II received saline infusion. Throughout the infusion process, hemodynamic data, respiratory rate, oxygen saturation, sedation, pain, Bromage score, amnesia, bispectral index, and side effects were recorded. Postoperative hemodynamic measurements, oxygen saturation, sedation, pain scores were obtained. Sedation and pain were evaluated using the Ramsay and visual analog scales, respectively. Analgesics were administered in cases with high scores on the visual analog scale. Postoperative analgesic consumption, side effects, treatments were recorded. No significant differences were found between the groups with respect to oxygen saturation, respiratory rate, pain, and side effects in the intraoperative period. Time to onset of sensorial block, maximum sensorial block, onset of motor block, and maximum motor block; bispectral index values; and apex heartbeat until 80 min of infusion, systolic arterial blood pressure until 90 min, and diastolic arterial blood pressure until 50 min were lower, whereas amnesia and sedation levels were higher in dexmedetomidine group. Postoperative pain and analgesic requirement were not different. Apex heartbeat at 15 min and systolic arterial blood pressure at 30 min were lower and sedation scores were higher in the dexmedetomidine infusion group. We demonstrated dexmedetomidine infusion had a hemodynamic depressant effect intraoperatively whereas it had no significant effect on peripheral oxygen saturation, respiratory rate, visual analog scale scores, and side effects. Dexmedetomidine infusion enhanced motor and sensory blockade quality and induced amnesia and sedation.

Randomised clinical trial comparing clinically relevant sedation outcome measures in dogs after intramuscular administration of medetomidine in combination with midazolam or butorphanol for routine diagnostic imaging procedures

The aim of this study was to investigate the sedative effects of medetomidine in combination with midazolam or butorphanol for routine imaging procedures in dogs. Eighty client owned dogs were recruited in a prospective, randomised, blinded clinical study and randomly assigned to receive one of four treatments intramuscularly (IM): (1) 30μg/kg medetomidine (Med30); (2) 20μg/kg medetomidine combined with 0.3mg/kg butorphanol (Med20But0.3); (3) 20μg/kg medetomidine combined with 0.3mg/kg midazolam (Med20Mid0.3); and (4) 10μg/kg medetomidine combined with 0.3mg/kg midazolam (Med10Mid0.3). The level of sedation was evaluated using a composite sedation scale assessed by one investigator (0=no sedation, 15=profound sedation). The number of dogs deemed to be adequately clinically sedated and the dose of propofol administered as rescue sedation were recorded. Mean±standard deviation sedation scores at 30min after the commencement of treatment in the groups that received Med20But0.3 (9.8±4) and Med20Mid0.3 (8.9±4.4) were not statistically significantly different from each other, but were significantly different from the group receiving Med10Mid0.3 (5.6±3.6). Only Med20But0.3 was significantly associated with adequate clinical sedation, while Med10Mid0.3 was associated with 85% sedation failure. The rescue sedation dose of propofol (1.5±1mg/kg) for the Med10Mid0.3 group was significantly higher than for other treatments. A sedation score≥10 out of 15 was a satisfactory cut-off to predict adequate clinical sedation. In healthy dogs, the combination of medetomidine with midazolam did not provide comparable sedation to the same dose of medetomidine in combination with butorphanol in a clinical setting.

Dexmedetomidine versus Magnesium Sulfate in Anesthesia for Cochlear Implantation Surgery in Pediatric Patients

Context:

Cochlear implantation surgery represents a great advance in ENT surgeries. Special anesthetic managements were required to provide bloodless surgical field and monitoring of the facial nerve.

Aims:

We aimed to compare both dexmedetomidine and magnesium sulfate as regards their efficacy in inducing deliberate hypotension and providing better quality of the surgical field during cochlear implantation in pediatrics.

Settings and Design:

Prospective, randomized double-blinded study.

Subjects and Methods:

Forty-six pediatric patients aging 1.5–2.5 years of either sex with American Society of Anesthesiologists physical status classes I and II were randomized into dexmedetomidine (D) group (n = 23) and magnesium sulfate (M) group (n = 23). In the D group, after induction of anesthesia but before the surgery, a bolus dose of 0.4 μg/kg slowly infused over 10 min, then continuous infusion by a rate of 0.4 μg/kg/h until the end of surgery. In M group, after induction of anesthesia but before the surgery, magnesium sulfate 10% (50 mg/kg) was given slowly, then continuous infusion by a rate of 10 mg/kg/h during the whole surgery. Intraoperative hemodynamics, quality of surgical field, fentanyl consumption, blood loss, operative time, FLACC pain scores, and adverse effects were compared in both groups.

Statistical Analysis Used:

Data were presented as mean ± standard deviation, ranges, numbers, and percentages as appropriate. Comparison of demographic data and time of surgery was done by Student's t-test. Two-way analysis of variance with correction for repeated measurements was used for heart rate and blood pressure comparison. Mann–Whitney U-test was used for nonparametric measurements.

Results:

Surgical field score and blood loss were better in D group than M group. Fentanyl consumption was less in D group than M group. Heart rate and mean atrial blood pressure were lower in D group except in the initial times than M group.

Conclusions:

In our study, both drugs were effective in achieving hypotensive anesthesia in pediatrics; however, dexmedetomidine proved to have superior effect on the surgical field and blood loss compared to magnesium sulfate with no intra- and post-operative complications for cochlear implantation surgery.

Dexmedetomidine versus propofol on the sedation of pediatric patients during magnetic resonance imaging (MRI) scanning: a meta-analysis of current studies

Magnetic resonance imaging (MRI) is a widely applied diagnostic approach for detection of pediatric diseases. Sedatives are commonly used to acquire the accurate MRI images. Dexmedetomidine and propofol serve as sole or combined sedatives in pediatric MRI scanning. This meta-analysis aimed to compare the efficacy of dexmedetomidine and propofol in children ubdergoing MRI. Pubmed, Cochrane Library and Web of Science were searched up to June, 2017. Onset of sedation time, recovery time, sedation time, MRI time, MRI quality and emergence delirium were analyzed. 6 studies with 368 subjects were enrolled in this meta-analysis. The pooling data showed that propofol had a shorter onset of sedation time (WMD: 6.05, 95% CI: 3.12 – 8.98, P < 0.0001) and recovery time (WMD: 1.01, 95% CI: 0.36–1.67, P < 0.001) than dexmedetomidine. But for sedation time and MRI scanning time, there were no differences between the two groups (sedation time: P = 0.29; MRI scanning time: P = 0.50). There were no significance between dexmedetomidine and propofol on MRI quality (MRI quality 1: P = 1.00; MRI quality 2: P = 0.68; MRI quality 3: P = 0.45). Two studies using Pediatric Anesthesia Emergence Delirium (PAED) to assess emergence delirium 10 minutes after awakening showed that propofol had a lower PAED than dexmedetomidine (WMD: 2.57, 95% CI: 0.15–5.00, P = 0.04). Thus, propofol should be encouraged in pediatric patients undergoing MRI for its better sedative effects and a low incidence of emergence delirium.

Effectiveness of dexmedetomidine as premedication prior to electroconvulsive therapy, a Randomized controlled cross over study

BACKGROUND

This study evaluated the effect of dexmedetomidine on the acute hyperdynamic response, duration of seizure activity, and recovery profile in patients undergoing electroconvulsive therapy (ECT).

AIMS

To study the effectiveness of dexmedetomidine 1 μg/kg intravenous in ECT in terms of attenuation of the hyperdynamic response, seizures duration, and sedation.

DESIGN

This was a prospective, randomized, double-blinded, crossover study.

MATERIALS AND METHODS

Thirty patients were included in the study and were treated as both cases and controls. The study drug was given 10 min before induction of anesthesia. Vital parameters and recovery scores were recorded.

RESULTS

In Group D, heart rates at 3^rd and 5^th min after electric stimulus (T6 and T7, respectively) were 94.5 ± 20.1 and 90.4 ± 12.8/min as compared to 111.9 ± 15.5 and 109.0 ± 13.7 in Group N, respectively (P < 0.0001). The systolic blood pressure in Group D and Group N were 116.53 ± 26.09 and 138.03 ± 19.32 at T6, respectively (P < 0.001). Diastolic blood pressure and mean arterial pressure were significantly reduced after induction and electric stimulus in Group D. The seizures duration was similar in both groups. Modified Aldrete's Score and Richmond Agitation-Sedation Score were prolonged in Group D.

CONCLUSION

Dexmedetomidine, before the induction of anesthesia, prevents the acute hyperdynamic responses to ECT without altering the seizures duration. However, patients may have delayed recovery and delayed discharge.

Neuroprotection and neurotoxicity in the developing brain: an update on the effects of dexmedetomidine and xenon

Growing and consistent preclinical evidence, combined with early clinical epidemiological observations, suggest potentially neurotoxic effects of commonly used anesthetic agents in the developing brain. This has prompted the FDA to issue a safety warning for all sedatives and anesthetics approved for use in children under three years of age. Recent studies have identified dexmedetomidine, the potent α2-adrenoceptor agonist, and xenon, the noble gas, as effective anesthetic adjuvants that are both less neurotoxic to the developing brain, and also possess neuroprotective properties in neonatal and other settings of acute ongoing neurologic injury. Dexmedetomidine and xenon are effective anesthetic adjuvants that appear to be less neurotoxic than other existing agents and have the potential to be neuroprotective in the neonatal and pediatric settings. Although results from recent clinical trials and case reports have indicated the neuroprotective potential of xenon and dexmedetomidine, additional randomized clinical trials corroborating these studies are necessary. By reviewing both the existing preclinical and clinical evidence on the neuroprotective effects of dexmedetomidine and xenon, we hope to provide insight into the potential clinical efficacy of these agents in the management of pediatric surgical patients.

Evaluation of efficacy of dexmedetomidine versus propofol for sedation in children undergoing magnetic resonance imaging

Background:

A deep level of sedation is required for magnetic resonance imaging (MRI) in children to ensure optimum image quality. The present study was conducted to evaluate the efficacy and safety of dexmedetomidine versus propofol for sedation in children undergoing MRI.

Materials and Methods:

A total of sixty children aged 2–10 years, having physical status 1 or 2 according to the American Society of Anesthesiologists, undergoing MRI were included in the study. Group D: (n = 30) received injection dexmedetomidine 2 μg/kg for 10 min followed by continuous infusion of 1.0 μg/kg/h. Group P (n = 30) received injection propofol 1 mg/kg bolus followed by continuous infusion of 100 μg/kg/min.

Results:

The mean time for onset of sedation in Group D was much longer than in Group P (P = 0.000). Mean duration of sedation was comparable in the two groups. The number of patients requiring increased infusion of study drug was significantly higher in Group D (30%) as compared to Group P (16.7%) (P < 0.05). The average recovery time in Group D was much longer than in Group P (P < 0.001).

Conclusion:

Propofol had an advantage of providing rapid onset of sedation and quicker recovery time. Dexmedetomidine resulted in a better preservation of respiratory rate and oxygen saturation, so it may be more suitable in children who are prone to respiratory depression. Hence, both the drugs could achieve required sedation in children posted for MRI.

Efficacy of Dexmedetomidine as a Sole Sedative Agent in Small Diagnostic and Therapeutic Procedures: A Systematic Review

Dexmedetomidine is an upcoming agent with sedative, anxiolytic, and analgesic properties. This review summarizes empirical evidence for the efficacy of dexmedetomidine as a sole sedative agent, and its effectiveness for small diagnostic and therapeutic procedure, in comparison with other frequently used sedatives. All randomized controlled trials on the effect of dexmedetomidine were reviewed. Pain level, patient satisfaction, operator satisfaction, procedure duration, recovery time, and hemodynamic and respiratory characteristics were examined. A total of 1993 patients (1,621 adults; 372 children) from 35 studies were included. In the adult studies, dexmedetomidine yielded significantly lower pain levels compared to the other sedatives (in 31.25% of the included studies) and significantly more patient satisfaction (68.2%). In studies on children, more favorable results concerning respiratory safety and the level of adequate sedation were found compared to the control sedatives. Implications for future studies are discussed.

Pharmacokinetics and pharmacodynamics of dexmedetomidine

Dexmedetomidine is an alpha-2 adrenoceptor agonist and has been used as a general anesthetic, sedative and analgesic for about 30 years. The aim of this paper is to review the pharmacokinetics and pharmacodynamics of dexmedetomidine, evaluate physiological factors that may affect the pharmacokinetics of dexmedetomidine, and summarize the pharmacodynamics of dexmedetomidine at different plasma levels. The pharmacokinetic parameters reported in previous studies according to noncompartmental analyses or population modeling results are compared. We concluded that the pharmacokinetic profile can be adequately described by a two-compartment model in population pharmacokinetic modeling. Body weight, height, albumin level, cardiac output, disease condition and other factors were considered to have significant influence on the clearance and/or distribution volume in different population pharmacokinetic models. The pharmacological effects of dexmedetomidine, such as sedation, heart rate reduction and biphasic change of blood pressure, vary at different plasma levels. These findings provide a reference for individualizing the dose of dexmedetomidine and achieving the desired pharmacological effects in clinical applications.

Usability of dexmedetomidine for deep sedation in infants and small children with respiratory morbidities

BACKGROUND

Children with respiratory morbidities are at increased risk of developing adverse respiratory events while undergoing deep sedation. Dexmedetomidine possesses sedative properties with minimal respiratory depression. This report aimed to determine the usability of dexmedetomidine in children with significant respiratory morbidities who require deep sedation.

METHODS

Medical records of children with ASA classification III who had at least three characteristics of respiratory morbidities and who received dexmedetomidine sedation for magnetic resonance imaging (MRI) between January 2014 and May 2015 were retrospectively reviewed. Dexmedetomidine was administered as a bolus of 1 μg/kg over 10 min followed by 1 μg/kg/h infusion. If necessary, an additional bolus dose was given and the infusion rate was increased to 2 μg/kg/h. Respiratory morbidities, haemodynamic parameters, total dexmedetomidine dose, adverse cardiorespiratory events and sedation characteristics were analysed.

RESULTS

Nineteen out of 642 children who underwent MRI were eligible for evaluation. Seventeen children (89%) had at least four characteristics of respiratory morbidities. The median [IQR] age was 9 months [3.5-14]. All patients completed MRI scans while breathing spontaneously via the native airway. No episodes of adverse respiratory events or haemodynamic instability were observed. Children who were administered a lower dexmedetomidine dose and had a shorter sedation time were more likely to be younger than 1 year of age.

CONCLUSION

These data demonstrate that dexmedetomidine deep sedation was well-tolerated in children with significant respiratory morbidities. Moreover, children younger than 1 year of age were administered lower dexmedetomidine dose than children older than 1 year of age for the same sedation level.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT02555605.

Treatment of Postoperative Pain in Pediatric Operations: Comparing the Efficiency of Bupivacaine, Bupivacaine-Dexmedetomidine and Bupivacaine-Fentanyl for Caudal Block

BACKGROUND

Caudal analgesia is a common method for postoperative pain management in pediatric patients. Additive agents such as opioids and α₂ agonists have been used to enhance the analgesic effects of local anesthetics for caudal block.

OBJECTIVES

The aim of this study was to compare the additive effects of dexmedetomidine and fentanyl on bupivacaine-induced caudal analgesia in pediatric patients who had undergone elective inguinal hernia repair.

METHODS

This randomized, double-blind clinical trial included children aged 1 - 5 years who were divided into three groups: the bupivacaine group (Group B) received 0.25% bupivacaine (1 ml/kg), the bupivacaine-dexmedetomidine group (Group BD) received 0.25% bupivacaine (1 mL/kg) plus 2 µg/kg dexmedetomidine, and the bupivacaine-fentanyl group (Group BF) received 0.25% bupivacaine (1 mL/kg) plus 2 µg/kg fentanyl. The hemodynamic variables (heart rate, systolic blood pressure, respiratory rate, and peripheral arterial oxygen saturation) were measured perioperatively. Pain, sedation and motor block scores and adverse events (nausea and vomiting, pruritis, hypotension, bradycardia, urinary retention and respiratory depression) were documented at 30 and 60 minutes, and the 1st, 2nd, 4th, 6th, 12th and 24th hours after the operation. The other recordings include the duration of surgery and analgesic requirement.

RESULTS

A total of 61 patients were analyzed. The lowest pain scores were found in the BD group at all time points (P < 0.001). The sedation scores were higher in the BD group than in the other two groups at all time points (P < 0.001). No motor block was observed after the operation. Only three patients required analgesic administration 2 to 6 hours after the operation in group B. No side effects were observed in any of the groups, and there was no significant difference in the duration of surgery among the three groups.

CONCLUSIONS

The results show that the analgesic and sedative effects were better when dexmedetomidine was added to bupivacaine than when fentanyl was added or bupivacaine alone was administered in the pediatric population studied here that underwent elective inguinal hernia repair.

Dexmedetomidine versus Propofol: Is One Better Than the Other for MRI Sedation in Children?

Objective The aim of this article is to determine whether dexmedetomidine or propofol is better for MRI sedation in children. Design This study is a retrospective review of patients sedated with dexmedetomidine or propofol for MRI between July 2007 and July 2015. Dexmedetomidine group (group D) was administered a bolus of 2 µg/kg over 10 minutes followed by a 1 ug/kg/hour infusion. Propofol group (group P) received a bolus of 2 mg/kg over 2 minutes followed by 83 µg/kg/minute infusion. Results Of the 996 cases completed, 452 were in group P and 544 were in group D. Patients in group P were heavier and older than those in group D. All the patients except one in group D completed the procedures. Hypotension occurred in 59% in group P versus 4% in group D (89 ± 11.4 SBP vs. 103.80 ± 19.4; p < 0.05). Bradycardia was observed in 2.9% in group P versus 0.6% in group D. Apnea occurred in two patients in group D. Although procedure time was longer in patients receiving propofol versus dexmedetomidine (58.87 ± 28.17 vs. 45 ± 23.6; p < .05), the discharge time was significantly shorter (37. ± 12.30 vs. 92.61 ± 28.19; p < 0.05). Conclusion Dexmedetomidine appears to provide a useful alternative to propofol for MRI sedation with a longer recovery time, stable hemodynamics, and less reliable respiratory profile, while the propofol had the advantage of quicker onset and rapid recovery.

Clinical study of midazolam sequential with dexmedetomidine for agitated patients undergoing weaning to implement light sedation in intensive care unit

PURPOSE

To evaluate midazolam sequential with dexmedetomidine for agitated patients undergoing weaning to implement light sedation in ICU.

METHODS

This randomized, prospective study was conducted in Tianjin Third Central Hospital, China. Using a sealed-envelope method, the patients were randomly divided into 2 groups (40 patients per group). Each patient of group A received an initial loading dose of midazolam at 0.3-3mg/kg·h 24 h before extubation, followed by an infusion of dexmedetomidine at a rate of 0.2-1 μg/kg·h until extubation. Each patient of group B received midazolam at a dose of 0.3-3 mg/kg·h until extubation. The dose of sedation was regulated according to RASS sedative scores maintaining in the range of -2-1. All patients were continuously monitored for 60 min after extubation. During the course, heart rate (HR), mean artery pressure (MAP), extubation time, adverse reactions, ICU stay, and hospital stay were observed and recorded continuously at the following time points: 24 h before extubation (T1), 12 h before extubation (T2), extubation (T3), 30 min after extubation (T4), 60 min after extubation (T5).

RESULTS

Both groups reached the goal of sedation needed for ICU patients. Dexmedetomidine was associated with a significant increase in extubation quality compared with midazolam, reflected in the prevalence of delirium after extubation (20% (8/40) vs 45% (18/40)), respectively (p= 0.017). There were no clinically significant decreases in HR and MAP after infusing dexmedetomidine or midazolam. In the group A, HR was not significantly increased after extubation; however, in the group B, HR was significantly increased compared with the preextubation values (p < 0.05). HR was significantly higher in the group B compared with the group A at 30 and 60 min after extubation (both, p <0.05). Compared with preextubation values, MAP was significantly increased at extubation in the group B (p < 0.05) and MAP was significantly higher at T3, T4, T5 in the group B than group A (p < 0.05). There was a significant difference in extubation time ((3.0 ± 1.5) d vs (4.3 ± 2.2) d, p < 0.05), ICU stay ((5.4 ± 2.1) d vs (8.0 ± 1.4) d, p < 0.05), hospital stay ((10.1 ± 3.0) d vs (15.3 ± 2.6) d, p <0.05) between group A and B.

CONCLUSION

Midazolam sequential with dexmedetomidine can reach the goal of sedation for ICU agitated patients, meanwhile it can maintain the respiratory and circulation parameters and reduce adverse reactions.

Effect of dexmedetomidine on acute lung injury in experimental ischemia-reperfusion model

PURPOSE

Ischemia-reperfusion injury is one of the consequences of tourniquet application for extremity surgery. The aim of the study was to establish the effect of dexmedetomidine on the acute lung injury following lower extremity experimental ischemia-reperfusion model in rats.

METHODS

Twenty-eight Wistar-Albino breed Rats were recruited after Ethics Committee approval and allocated into 4 groups, each with 7 subjects. Group 1 (SHAM) received only anesthesia. Group 2 (IR) had experienced 3h of ischemia and 3h of reperfusion using left lower extremity tourniquet after anesthesia application. Groups 3 (D-50) and 4 (D-100) had undergone the same procedures as in the Group 2, except for receiving 50 and 100mg·kg^-1, respectively, dexmedetomidine intraperitoneally 1h before the tourniquet release. Blood samples were obtained for the analysis of tumor necrosing factor-α and interleukin-6. Pulmonary tissue samples were obtained for histological analysis.

RESULTS

No significant difference regarding blood tumor necrosing factor-α and interleukin-6 values was found among the groups, whereas pulmonary tissue injury scores revealed significant difference. Histological scores obtained from the Group 2 were significantly higher from those in the Groups 1, 3 and 4 with p-values 0.001 for each comparison. Moreover, Group 1 scores were found to be significantly lower than those in the Groups 3 and 4 with p-values 0.001 and 0.011, respectively. No significant difference was observed between the Groups 3 and 4.

CONCLUSION

Dexmedetomidine is effective in reduction of the experimental ischemia-reperfusion induced pulmonary tissue injury in rats, formed by extremity tourniquet application.