Dexmedetomidine in Children

Efficacy and Safety of Dexmedetomidine for Prolonged Sedation in the PICU: A Prospective Multicenter Study (PROSDEX)

OBJECTIVES

We sought to evaluate dexmedetomidine efficacy in assuring comfort and sparing conventional drugs when used for prolonged sedation (≥24 hr) in critically ill patients, by using validated clinical scores while systematically collecting drug dosages. We also evaluated the safety profile of dexmedetomidine and the risk factors associated with adverse events.

DESIGN

Observational prospective study.

SETTING

Nine tertiary-care PICUs.

PATIENTS

Patients less than 18 years who received dexmedetomidine for greater than or equal to 24 hours between January 2016 and December 2017.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

One-hundred sixty-three patients (median age, 13 mo; interquartile range, 4-71 mo) were enrolled. The main indication for dexmedetomidine use was as an adjuvant for drug-sparing (42%). Twenty-three patients (14%) received dexmedetomidine as monotherapy. Seven percent of patients received a loading dose. The median infusion duration was 108 hours (interquartile range, 60-168 hr), with dosages between 0.4 (interquartile range, 0.3-0.5) and 0.8 µg/kg/hr (interquartile range, 0.6-1.2 µg/kg/hr). At 24 hours of dexmedetomidine infusion, values of COMFORT-B Scale (n = 114), Withdrawal Assessment Tool-1 (n = 43) and Cornell Assessment of Pediatric Delirum (n = 6) were significantly decreased compared with values registered immediately pre dexmedetomidine (p < 0.001, p < 0.001, p = 0.027). Dosages/kg/hr of benzodiazepines, opioids, propofol, and ketamine were also significantly decreased (p < 0.001, p < 0.001, p = 0.001, p = 0.027). The infusion was weaned off in 85% of patients, over a median time of 36 hours (interquartile range, 12-48 hr), and abruptly discontinued in 15% of them. Thirty-seven percent of patients showed hemodynamic changes, and 9% displayed hemodynamic adverse events that required intervention (dose reduction in 79% of cases). A multivariate logistic regression model showed that a loading dose (odds ratio, 4.8; CI, 1.2-18.7) and dosages greater than 1.2 µg/kg/hr (odds ratio, 5.4; CI, 1.9-15.2) increased the odds of hemodynamic changes.

CONCLUSIONS

Dexmedetomidine used for prolonged sedation assures comfort, spares use of other sedation drugs, and helps to attenuate withdrawal syndrome and delirium symptoms. Adverse events are mainly hemodynamic and are reversible following dose reduction. A loading dose and higher infusion dosages are independent risk factors for hemodynamic adverse events.

Dexmedetomidine Provides Fewer Respiratory Events Compared With Propofol and Fentanyl During Third Molar Surgery: A Randomized Clinical Trial

PURPOSE

Propofol and fentanyl can cause airway obstruction and respiratory depression when used together for intravenous sedation. This study investigated whether dexmedetomidine and midazolam would decrease respiratory events requiring intervention during deep sedation compared with propofol, fentanyl, and midazolam.

PATIENTS AND METHODS

A prospective, randomized, double-blinded, controlled trial was designed to assess 2 intravenous treatment groups during third molar surgery. Patients were randomized into 2 groups. The control group (group P) received 0.8 μg/kg of fentanyl followed by propofol infusion at 125 μg/kg per minute over a 10-minute period with intraoperative boluses of 0.1 μg/kg. The study group (group D) received dexmedetomidine bolus infusion of 1 μg/kg over a 10-minute period followed by maintenance infusion at 0.5 μg/kg per hour. Both groups were given 0.03 mg/kg of midazolam before infusion. Scorers, masked to group, viewed the procedure remotely and evaluated the primary outcome variable of respiratory events requiring intervention. Secondary outcome variables evaluated by the scorers included the Behavioral Pain Scale for non-intubated patients at initial injection, cooperation score at 5 and 15 minutes, and time to ambulation and discharge. Patient satisfaction and hemodynamic stability were measured. The difference between groups regarding the occurrence of respiratory events was tested using the Fisher exact test, and mixed-effects models were used to compare repeated vital signs.

RESULTS

The sample was composed of 141 patients randomly assigned to either group P (n = 67) or group D (n = 74). No statistically significant differences in the distribution of study variables were found between groups at baseline. A statistically significant difference in respiratory events requiring deliberate intervention existed between group P (25.4%) and group D (2.7%) (P < .0001). No statistically significant difference was found between groups for Behavioral Pain Scale score, cooperation score, time to ambulation or discharge, and patient satisfaction.

CONCLUSIONS

Using dexmedetomidine and midazolam for outpatient surgery resulted in fewer respiratory events requiring deliberate intervention compared with propofol, fentanyl, and midazolam. Ambulation and discharge times were not prolonged using dexmedetomidine.

Intrathecal dexmedetomidine and postoperative pain: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND OBJECTIVE

A systematic review and meta-analysis of randomized controlled trials (RCTs) was undertaken to evaluate the effect of intrathecal dexmedetomidine (DEX) on the duration of postoperative analgesia, postoperative pain scores and incidences of adverse effects.

DATABASES AND DATA TREATMENT

Database search was performed from inception until January 2019. All RCTs analysing acute postoperative pain characteristics after intrathecal DEX administration in adults undergoing spinal anaesthesia for elective surgery were included. The primary outcome was postoperative analgesic duration, defined as the time to first analgesic request. The secondary outcomes included pain scores at 6, 12 and 24 postoperative hours and rates of hypotension, bradycardia, shivering and postoperative nausea and vomiting.

RESULTS

Twenty-four studies comprising a total of 1,460 patients were included. Postoperative analgesic duration was prolonged with intrathecal DEX compared to placebo, with a pooled mean difference (MD) of 191.3 min (95% CI 168.8-213.8). Patients who received intrathecal DEX reported lower Visual Analogue Scale scores at 24 postoperative hours compared with those patients receiving placebo, with a MD (95% CI) of -1.05 (-1.89 to -0.20, p = 0.02). There were no differences in the incidence of adverse effects, except for a lower rate of postoperative shivering in the intrathecal DEX group (pooled relative risk 0.58, 95% CI 0.34-0.98, p = 0.04).

CONCLUSIONS

Compared to placebo, intrathecal DEX prolonged postoperative analgesic duration, reduced 24-hr pain intensity and reduced the incidence of shivering without an increase in other adverse effects.

SIGNIFICANCE

The analgesic role of intrathecal DEX is promising due to its ability to significantly increase postoperative analgesic duration when compared with placebo. Its usage can be considered for patients undergoing surgeries with significant postoperative pain, particularly those intolerant of systemic analgesia. However, the optimal dose for various surgeries as well as its long-term neurological effects warrants further studies.

Pharmacokinetics and Sedative Effects of Intranasal Dexmedetomidine in Ambulatory Pediatric Patients

BACKGROUND

Our aim was to characterize the pharmacokinetics and sedative effects of intranasally (IN) administered dexmedetomidine used as an adjuvant in pediatric patients scheduled for magnetic resonance imaging (MRI) requiring sedation.

METHODS

This was an open-label, single-period study without randomization. Pediatric patients from 5 months to 11 years of age scheduled for MRI and receiving IN dexmedetomidine for premedication as part of their care were included in this clinical trial. Single doses of 2-3 µg·kg of dexmedetomidine were applied IN approximately 1 hour before MRI. Five or 6 venous blood samples were collected over 4 hours for dexmedetomidine concentration analysis. Sedation was monitored with Comfort-B scores, and vital signs were recorded. Pharmacokinetic variables were calculated with noncompartmental methods and compared between 3 age groups (between 1 and 24 months, from 24 months to 6 years, and over 6-11 years).

RESULTS

We evaluated 187 consecutive patients for suitability, of which 132 were excluded. Remaining 55 patients were recruited, of which 5 were excluded before the analysis. Data from 50 patients were analyzed. The average (standard deviation [SD]) dose-corrected peak plasma concentration (Cmax) was 0.011 liter (0.0051), and the median (interquartile range [IQR]) time to reach peak concentration (tmax) was 37 minutes (30-45 minutes). There was negative correlation with Cmax versus age (r = -0.58; 95% confidence interval [CI], -0.74 to -0.37; P < .001), but not with tmax (r = -0.14; 95% CI, 0.14-0.39; P = .35). Dose-corrected areas under the concentration-time curve were negatively correlated with age (r = -0.53; 95% CI, 0.70 to -0.29; P < .001). Median (IQR) maximal reduction in Comfort-B sedation scores was 8 (6-9), which was achieved 45 minutes (40-48 minutes) after dosing. Median (IQR) decrease in heart rate was 15% (9%-23%) from the baseline.

CONCLUSIONS

Dexmedetomidine is relatively rapidly absorbed after IN administration and provides clinically meaningful but short-lasting sedation in pediatric patients.

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.

The Use of Intranasal Dexmedetomidine and Midazolam for Sedated Magnetic Resonance Imaging in Children: A Report From the Pediatric Sedation Research Consortium

OBJECTIVE

The objective of this study was to describe the use of intranasal dexmedetomidine (IN DEX) for sedated magnetic resonance imaging (MRI) examinations in children. The use of IN DEX for MRI in children has not been well described in the literature.

MATERIALS AND METHODS

The Pediatric Sedation Research Consortium (PSRC) is a collaborative and multidisciplinary group of sedation practitioners dedicated to understanding and improving the process of pediatric sedation. We searched the 2007 version of the PSRC database solely for instances in which IN DEX was used for MRI diagnostic studies. Patients receiving intravenous medications were excluded. Patient demographics, IN DEX dose, adjunct medications and dose, as well as procedure completion, complications, interventions, and monitoring providers were analyzed.

RESULTS

A total of 224 sedation encounters were included in our primary analysis. There were no major adverse events. Most sedations (88%) required no intervention. Registered nurses were the monitoring provider in over 99% of cases. The median (interquartile range) dose of dexmedetomidine was 3 (2.5-3) mcg/kg. Adjunctive midazolam was used in 219/224 (98%) of the cases. All procedures were completed.

CONCLUSIONS

This report from the PSRC shows that IN DEX in combination with midazolam is an effective medication regimen for children who require an MRI with sedation.

Dexmedetomidine Improves Cardiovascular and Ventilatory Outcomes in Critically Ill Patients: Basic and Clinical Approaches

Dexmedetomidine (DEX) is a highly selective α2-adrenergic agonist with sedative and analgesic properties, with minimal respiratory effects. It is used as a sedative in the intensive care unit and the operating room. The opioid-sparing effect and the absence of respiratory effects make dexmedetomidine an attractive adjuvant drug for anesthesia in obese patients who are at an increased risk for postoperative respiratory complications. The pharmacodynamic effects on the cardiovascular system are known; however the mechanisms that induce cardioprotection are still under study. Regarding the pharmacokinetics properties, this drug is extensively metabolized in the liver by the uridine diphosphate glucuronosyltransferases. It has a relatively high hepatic extraction ratio, and therefore, its metabolism is dependent on liver blood flow. This review shows, from a basic clinical approach, the evidence supporting the use of dexmedetomidine in different settings, from its use in animal models of ischemia-reperfusion, and cardioprotective signaling pathways. In addition, pharmacokinetics and pharmacodynamics studies in obese subjects and the management of patients subjected to mechanical ventilation are described. Moreover, the clinical efficacy of delirium incidence in patients with indication of non-invasive ventilation is shown. Finally, the available evidence from DEX is described by a group of Chilean pharmacologists and clinicians who have worked for more than 10 years on DEX.

To Compare the Efficacy of Two Intravenous Combinations of Drugs Ketamine-Propofol vs Ketamine-Dexmedetomidine for Sedation in Children Undergoing Dental Treatment

Objective

To compare the efficacy of two intravenous combinations of drugs ketamine–propofol (KP) vs ketamine–dexmedetomidine (KD) for sedation in children undergoing dental treatment.

Study design

Thirty patients were selected, evaluated according to the predetermined criteria and divided in equal numbers of 15 amongst 2 groups KP and KD.

Materials and methods

Informed consent was taken, nil per oral (NPO) guidelines were followed and the study drug was administered. Dental procedure was performed. Heart rate (HR), blood pressure (BP) and oxygen saturation (SPO₂) were monitored continuously throughout the procedure. The modified Ramsay sedation (MRS) score was recorded along with Houpt sedation score. Recovery status was accessed by modified Aldrete's recovery scale.

Statistical analysis

Student t test was used for comparing HR, BP and SPO₂. Chi-square test was used to compare MRS, Houpt sedation score and modified Aldrete's recovery scale amongst the two groups KP and KD.

Results

The sedation achieved with both the groups was adequate. Both the drugs produce adequate hemodynamic stability.

Conclusion

Ketamine–dexmedetomidine has a better efficacy over the other group, ketamine–propofol.

How to cite this article

Joshi AB, Shankaranarayan UR, Hegde A, et al. To Compare the Efficacy of Two Intravenous Combinations of Drugs Ketamine–Propofol vs Ketamine–Dexmedetomidine for Sedation in Children Undergoing Dental Treatment. Int J Clin Pediatr Dent 2020;13(5):529–535.

Dexmedetomidine Promotes Hippocampal Neurogenesis and Improves Spatial Learning and Memory in Neonatal Rats

Background

Dexmedetomidine (Dex) is a highly selective α2-adrenoceptor agonist used as an off-label medication for pediatric sedation and analgesia. Recently, Dex was reported to exhibit neuroprotective efficacy in several brain injury models. Here we investigate whether neonatal Dex administration promotes hippocampal neurogenesis and enhances hippocampus-dependent spatial learning and memory under physiological conditions.

Methods

Postnatal day 7 (P7) pups were administered saline (vehicle control) or Dex (10, 20, or 40 µg/kg) by intraperitoneal injection. Neurogenesis and astrogenesis were examined in brain slices by BrdU immunostaining on P8 and changes in the expression levels of GDNF, NCAM, CREB, PSD95, and GAP43 were assessed by Western blotting on P35, respectively. Open field and Morris water maze (MWM) tests were conducted from P28 to P36 in order to assess effects on general motor activity and spatial learning, respectively.

Results

Dexmedetomidine at 20 µg/kg significantly enhanced neurogenesis and astrogenesis in hippocampus and upregulated GDNF, NCAM, CREB, PSD95, and GAP43 compared to vehicle and other Dex doses. Moreover, 20 µg/kg Dex-injected rats showed no changes in motor or anxiety-like behavior but performed better in the MWM test compared to all other groups.

Conclusion

Neonatal injection of Dex (20 µg/kg) enhances spatial learning and memory in rat pups, potentially by promoting hippocampal neurogenesis and synaptic plasticity via activation of GDNF/NCAM/CREB signaling.

Efficacy and safety of dexmedetomidine for prevention of withdrawal syndrome in the pediatric intensive care unit: protocol for an adaptive, multicenter, randomized, double-blind, placebo-controlled, non-profit clinical trial

Background

Prolonged treatment with analgesic and sedative drugs in the pediatric intensive care unit (PICU) may lead to undesirable effects such as dependence and tolerance. Moreover, during analgosedation weaning, patients may develop clinical signs of withdrawal, known as withdrawal syndrome (WS). Some studies indicate that dexmedetomidine, a selective α2-adrenoceptor agonist, may be useful to prevent WS, but no clear evidence supports these data. The aims of the present study are to evaluate the efficacy of dexmedetomidine in reducing the occurrence of WS during analgosedation weaning, and to clearly assess its safety.

Methods

We will perform an adaptive, multicenter, randomized, double-blind, placebo-controlled trial. Patients aged < 18 years receiving continuous intravenous analgosedation treatment for at least 5 days and presenting with clinical conditions that allow analgosedation weaning will be randomly assigned to treatment A (dexmedetomidine) or treatment B (placebo). The treatment will be started 24 h before the analgosedation weaning at 0.4 μg/kg/h, increased by 0.2 μg/kg/h per hour up to 0.8 μg/kg/h (neonate: 0.2 μg/kg/h, increased by 0.1 μg/kg/h per hour up to 0.4 μg/kg/h) and continued throughout the whole weaning time. The primary endpoint is the efficacy of the treatment, defined by the reduction in the WS rate among patients treated with dexmedetomidine compared with patients treated with placebo. Safety will be assessed by collecting any potentially related adverse event. The sample size assuring a power of 90% is 77 patients for each group (total N = 154 patients). The study was approved by the Ethics Committee of the University-Hospital S.Orsola-Malpighi of Bologna on 22 March 2017.

Discussion

The present trial will allow us to clearly assess the efficacy of dexmedetomidine in reducing the occurrence of WS during weaning from analgosedation drugs. In addition, the study will provide a unique insight into the safety profile of dexmedetomidine.

Trial registration

ClinicalTrials.gov, NCT03645603. Registered on 24 August 2018.

EudraCT, 2015–002114-80. Retrospectively registered on 2 January 2019.

Randomised Comparison between the Efficacy of Two Doses of Nebulised Dexmedetomidine for Premedication in Paediatric Patients

Objective

Nebulised dexmedetomidine can be an easy alternative for preoperative sedation in paediatric patients, but data regarding its efficacy are very limited.

Methods

This prospective, randomised, double-blind study included 66 patients aged between 1 and 8 years. Patients were divided into two groups as D2 and D3. The D2 group received 2 μg kg⁻¹ of nebulised dexmedetomidine, and the D3 group received 3 μg kg⁻¹ of nebulised dexmedetomidine preoperatively. All the patients received general anaesthesia and caudal epidural analgesia with 0.75 mL kg⁻¹ of 0.2% ropivacaine. Parental Separation Anxiety Scale at 30 min after the end of nebulisation, Mask Acceptance Score (MAS) during induction, haemodynamic variables, emergence agitation and duration of caudal analgesia were compared between the groups. Statistical analysis was done using Mann-Whitney U test and chi-square test. A p-value <0.05 was accepted as significant.

Results

All the parameters were comparable between the D2 and D3 groups; however, significantly more number of younger children was observed in the D3 group. Hence, further analysis was done after division into the lower age (1–3 years) and higher age (4–8 years) groups. In lower age group children, satisfactory parental separation was achieved in 100% of the patients in the D3 group compared to 20% of those in the D2 group (p=0.00). MAS was significantly better in the D3 group in both the lower (p=0.019) and higher (p=0.036) age groups.

Conclusion

We conclude that nebulised dexmedetomidine in a dose of 3 μg kg⁻¹ provides better parental separation and mask acceptance in younger children.

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.

Pharmacokinetics of Intranasally Administered Dexmedetomidine in Chinese Children

Background: Intranasal application is a comfortable, effective, nearly non-invasive, and easy route of administration in children. To date, there is, however, only one pharmacokinetic study on intranasal dexmedetomidine in pediatric populations and none in Chinese children available. Therefore, this study aimed to characterize the pharmacokinetics of intranasally administered dexmedetomidine in Chinese children.

Methods: Thirteen children aged 4 to 10 years undergoing surgery received 1 µg/kg dexmedetomidine intranasally. Arterial blood samples were drawn at various time points until 180 min after dose. Dexmedetomidine plasma concentrations were measured with high performance liquid chromatography (HPLC) and mass spectrometry. Pharmacokinetic modeling was performed by population analysis using linear compartment models with first-order absorption.

Results: An average peak plasma concentration of 748 ± 30 pg/ml was achieved after 49.6 ± 7.2 min. The pharmacokinetics of dexmedetomidine was best described by a two-compartment model with first-order absorption and an allometric scaling with estimates standardized to 70-kg body weight. The population estimates (SE) per 70 kg bodyweight of the apparent pharmacokinetic parameters were clearance CL/F = 0.32 (0.02) L/min, central volume of distribution V1/F = 34.2 (4.9) L, intercompartmental clearance Q2/F = 10.0 (2.2) L/min, and peripheral volume of distribution V2/F = 34.9 (2.3) L. The estimated absorption rate constant was Ka = 0.038 (0.004) min⁻¹.

Conclusions: When compared with studies in Caucasians, Chinese children showed a similar time to peak plasma concentration after intranasal administration, but the achieved plasma concentrations were about three times higher. Possible reasons are differences in age, ethnicity, and mode of administration.

Practicalities of Total Intravenous Anesthesia and Target-controlled Infusion in Children

Propofol administered in conjunction with an opioid such as remifentanil is used to provide total intravenous anesthesia for children. Drugs can be given as infusion controlled manually by the physician or as automated target-controlled infusion that targets plasma or effect site. Smart pumps programmed with pharmacokinetic parameter estimates administer drugs to a preset plasma concentration. A linking rate constant parameter (keo) allows estimation of effect site concentration. There are two parameter sets, named after the first author describing them, that are commonly used in pediatric target-controlled infusion for propofol (Absalom and Kataria) and one for remifentanil (Minto). Propofol validation studies suggest that these parameter estimates are satisfactory for the majority of children. Recommended target concentrations for both propofol and remifentanil depend on the type of surgery, the degree of surgical stimulation, the use of local anesthetic blocks, and the ventilatory status of the patient. The use of processed electroencephalographic monitoring is helpful in pediatric total intravenous anesthesia and target-controlled infusion anesthesia, particularly in the presence of neuromuscular blockade.

Comparative evaluation of intrathecal bupivacaine alone and bupivacaine combined with dexmedetomidine in cesarean section using spinal anesthesia: a meta-analysis

Objective

This meta-analysis was performed to evaluate the effect of spinal anesthesia (SA) using bupivacaine combined with dexmedetomidine (DEX) in cesarean section, analyze the adverse drug reactions induced by this mixture, and provide a reference for rational drug use.

Methods

Randomized controlled trials were obtained from the PubMed, Cochrane Library, and Embase databases. The primary outcome measure was the time to the highest sensory block level (min), and the secondary outcome measure was adverse effects.

Results

The time to the highest sensory block level was significantly shorter in the bupivacaine-DEX group than in the control group (standardized mean difference, −0.23; 95% confidence interval, −0.43 to −0.03). The incidence of shivering during the process of anesthesia, especially at a dose of 5 µg DEX, was significantly lower in the bupivacaine-DEX group than in the control group (odds ratio, 0.26; 95% confidence interval, 0.14–0.49). No significant differences were observed in the symptoms of hypotension, bradycardia, nausea/vomiting, or pruritus.

Conclusion

Compared with the use of bupivacaine alone for SA in cesarean section, adding dexmedetomidine during SA can significantly shorten the onset time and decrease the rate of shivering during anesthesia.

Guidelines for Monitoring and Management of Pediatric Patients Before, During, and After Sedation for Diagnostic and Therapeutic Procedures

The safe sedation of children for procedures requires a systematic approach that includes the following: no administration of sedating medication without the safety net of medical/dental supervision, careful presedation evaluation for underlying medical or surgical conditions that would place the child at increased risk from sedating medications, appropriate fasting for elective procedures and a balance between the depth of sedation and risk for those who are unable to fast because of the urgent nature of the procedure, a focused airway examination for large (kissing) tonsils or anatomic airway abnormalities that might increase the potential for airway obstruction, a clear understanding of the medication's pharmacokinetic and pharmacodynamic effects and drug interactions, appropriate training and skills in airway management to allow rescue of the patient, age- and size-appropriate equipment for airway management and venous access, appropriate medications and reversal agents, sufficient numbers of appropriately trained staff to both carry out the procedure and monitor the patient, appropriate physiologic monitoring during and after the procedure, a properly equipped and staffed recovery area, recovery to the presedation level of consciousness before discharge from medical/dental supervision, and appropriate discharge instructions. This report was developed through a collaborative effort of the American Academy of Pediatrics and the American Academy of Pediatric Dentistry to offer pediatric providers updated information and guidance in delivering safe sedation to children.

The comparison of dexmedetomidine and ketamine for pediatric dental surgery: A meta-analysis of randomized controlled studies

INTRODUCTION

Dexmedetomidine and ketamine are used for the sedation of pediatric dental surgery. We conduct a systematic review and meta-analysis to compare the sedation of dexmedetomidine and ketamine for pediatric dental surgery.

METHODS

PubMed, Embase, and the Cochrane Central Register of Controlled Trials were searched. Randomized controlled trials (RCTs) assessing the influence of dexmedetomidine versus ketamine on pediatric dental surgery are included. Two investigators independently have searched articles, extracted data, and assessed the quality of included studies. This meta-analysis is performed using the random-effect model.

RESULTS

Four RCTs involving 163 children are included in the meta-analysis. Compared with ketamine for pediatric dental surgery, dexmedetomidine results in comparable sedation level (very low quality, 2 RCTs, n = 40; Std. MD = -0.26; 95% CI = -0.74 to 0.23; P = .31), intraoperative analgesia scores (very low quality, 2 RCTs, n = 98; Std. MD = 0.17; 95% CI = -0.23 to 0.57; P = .40), postoperative analgesia scores (very low quality, 2 RCTs, n = 98; Std. MD = 0.23; 95% CI = -0.17 to 0.62; P = .27), DBP (very low quality, 3 RCTs, n = 123; Std. MD = -0.38; 95% CI = -1.04 to 0.27; P = .25) and SpO2 (very low quality, 3 RCTs, n = 123; Std. MD = 0.24; 95% CI = -0.20 to 0.69; P = .28), but significantly decreases heart rate (very low quality, 3 RCTs, n = 123; Std. MD = -1.51; 95% CI = -2.75 to -0.27; P = .02) and SBP (very low quality, 3 RCTs, n = 123; Std. MD = -0.62; 95% CI = -1.16 to -0.08; P = .02), longer recovery time (very low quality, 3 RCTs, n = 138; Std. MD = 1.74; 95% CI = 0.23 to 3.25; P = .02).

CONCLUSIONS

Dexmedetomidine and ketamine have similar sedation, analgesia scores, and hemodynamic balance, but very low quality of the evidence (GRADE) is revealed in this meta-analysis.

Randomised controlled trial of dexmedetomidine sedation vs general anaesthesia for inguinal hernia surgery on perioperative outcomes in infants

BACKGROUND

Neonates and infants undergoing general anaesthesia for hernia surgery are at risk of perioperative cardiorespiratory adverse events. The use of regional anaesthesia with dexmedetomidine preserves airway tone and may potentially avoid these complications. This study compares the perioperative conditions and adverse events between dexmedetomidine sedation with caudal block and general anaesthesia with caudal block for inguinal hernia surgery in infants.

METHODS

A randomised controlled trial was conducted in a tertiary hospital in Singapore involving 104 infants younger than 3 months, who were randomised to receive either dexmedetomidine sedation (DEX) with caudal block or general sevoflurane anaesthesia with tracheal intubation and caudal block (GA) for inguinal hernia surgery. Perioperative conditions, haemodynamics and adverse events were compared between groups.

RESULTS

Fifty-one infants received DEX and 48 infants received GA. In the DEX group, 46 infants (90.2%) had their operations completed solely under this technique, two (3.9%) were converted to general anaesthesia with intubation, and three (5.9%) required brief administration of nitrous oxide or low-dose sevoflurane. Overall, 96.1% of infants in the DEX group did not require intubation. Perioperative conditions were similar in both groups. The DEX group had significantly lower heart rates and higher mean arterial pressures intraoperatively. Two infants in the DEX group (3.9%) required postoperative intensive care admission compared with six infants (12.5%) in the GA group.

CONCLUSIONS

Dexmedetomidine sedation with caudal block provides a feasible alternative to general anaesthesia in infants undergoing hernia surgery. This technique avoids the need for tracheal intubation, which may be beneficial in neonates.

CLINICAL TRIAL REGISTRATION

NCT02559102.

Spontaneous Conversions of Supraventricular Tachycardia to Sinus Rhythm in Children After Premedication With Intranasal Dexmedetomidine: A Case Report

Intranasal dexmedetomidine administered as premedication before anesthesia and cardioversion appears to have the potential to facilitate the return of sinus rhythm. Two children, 3.5 and 1.5 years old, with recurrent supraventricular tachycardia in need of cardioversion have now on several occasions spontaneously returned to sinus rhythm within 20-40 minutes after intranasal administration of dexmedetomidine (4 μg/kg) with a mucosal atomization device. Both children were observed on all occasions at the pediatric outpatient clinic and could return home within 2 hours of cardioversion. For children with supraventricular tachycardia, a selective α2-agonist might be a valuable alternative to cardioversion with adenosine.

Median Effective Dose of Intranasal Dexmedetomidine for Transthoracic Echocardiography in Children with Kawasaki Disease Who Have a History of Repeated Sedation

Background

The aim of this study was to investigate the median effective dose (ED50) of intranasal dexmedetomidine for echocardiography in children with Kawasaki disease who had a history of repeated sedation.

Material/Methods

There were 73 pediatric Kawasaki disease patients aged 1 to 36 months enrolled in this study who had American Society of Anesthesiologists (ASA) I–II, were scheduled to undergo echocardiography under sedation. They were assigned to 2 groups (group A: age 1–18 months, and group B: age 19–36 months). Intranasal dexmedetomidine was administered before echocardiography. The dose of intranasal dexmedetomidine was determined with the up-down sequential allocation, and the initial dose was 2 μg/kg with an increment/decrement of 0.2 μg/kg. The ED50 of intranasal dexmedetomidine for sedation was determined with the up-and-down method of Dixon and Massey and probit regression. The time to effective sedation, time to regaining consciousness, vital signs, oxygen saturation, echocardiographic examination time, clinical side-effects, and characteristics of regaining consciousness were recorded and compared.

Results

The ED50 of intranasal dexmedetomidine for sedation was 2.184 μg/kg (95% CI, 1.587–2.785) in group A and 2.313 μg/kg (95% CI, 1.799–3.426) in group B. There were no significant differences in the time to sedation and time to regaining consciousness between groups. Additionally, change in hemodynamic and hypoxemia were not noted in both groups.

Conclusions

The ED50 of intranasal dexmedetomidine was determined in children with Kawasaki disease who had a history of repeated sedation to be appropriate for repeated-routine sedation of echocardiographic examination in pediatric patients. The ED50 of intranasal dexmedetomidine for echocardiography in this circumstance is similar to that in children receiving initial sedation.

Management of Anaesthesia

Surgical treatment of the craniovertebral junction (CVJ) requires excellent management by the anaesthetist. Patients undergoing this type of surgery have a wide range of concomitant diseases. Therefore, before proceeding to CVJ surgery, it is recommended to analyse the clinical aspects of the patient that could complicate the outcome of the surgical procedure.In this paper we aim to establish what constitutes the best surgical and anaesthesia management of these patients. We consider airway management, trying to identify the gold standard for the patient. We also consider the most appropriate intraoperative approach to guarantee the best management of the patient.

Effect of Single-Dose Dexmedetomidine on Intraoperative Hemodynamics and Postoperative Recovery during Pediatric Adenotonsillectomy

Background

In children undergoing adenotonsillectomy, smooth recovery from anesthesia without any respiratory compromise and excessive sedation or pain is always desirable. In this placebo-controlled study, we examined the effect of single dose of dexmedetomidine on intraoperative hemodynamics and postoperative recovery profile such as emergence agitation (EA), pain, and sedation in children undergoing adenotonsillectomy.

Methods

Sixty American Society of Anesthesiologists I or II children in the age group of 5-10 years, undergoing adenotonsillectomy were randomly assigned to receive dexmedetomidine 1 μg/kg (Group D) or volume-matched saline (placebo) (Group C), 10 min before induction of anesthesia. Intraoperative heart rate (HR) and mean blood pressure (MBP), duration of surgery, time to extubation, EA using Paediatric Anaesthesia Emergence Delirium (PAED) scale, level of sedation in postanesthesia care unit using Ramsay sedation score (RSS), and postoperative visual analog score (VAS) for pain were recorded and compared.

Results

Dexmedetomidine group had lower HR and stable MBP, compared to the control group (P < 0.05). Postoperatively, the agitation score (PAED scale score) was statistically lower in Group D compared to Group C (13.84 ± 1.39; median 14 in Group C vs. 9.37 ± 1.33; median 9.5 in Group D; P < 0.001). All patients in Group C had PAED scale score >12, while only 6.67% of patients in Group D had PAED scale score of 12. The patients in Group D had higher RSS (2.62 ± 0.49 in Group D vs. 1.60 ± 0.50, P = 0.004); none of the patients were excessively sedated or had RSS >3. No significant difference was found in VAS score of the groups at all times, except at 0 h (P = 0.002). Time to extubation was significantly longer in the dexmedetomidine group (7.70 ± 1.62 min in Group D vs. 5.23 ± 1.91 min in Group C; P = 0.001).

Conclusion

Premedication of dexmedetomidine at the dose of 1 μg/kg in children undergoing adenotonsillectomy resulted in favorable effect on intraoperative hemodynamics, significant decrease in postoperative EA without causing any excessive sedation, desaturation, or any other drug-related adverse events.

Sedation effects of intranasal dexmedetomidine combined with ketamine and risk factors for sedation failure in young children during transthoracic echocardiography

BACKGROUND

Sedation is often required for young children during transthoracic echocardiography. Dexmedetomidine and ketamine are two sedatives that are commonly used in children for procedural sedation, but they have some disadvantages when they are used alone.

AIMS

The aim of this retrospective study was to analyze the effects and safety of intranasal sedation with a combination of dexmedetomidine and ketamine during transthoracic echocardiography in young children and to analyze risk factors for sedation failure.

METHODS

After IRB approval, we retrospectively evaluated data on patients who underwent echocardiography between May 2016 and August 2017 utilizing a combination of dexmedetomidine 2 μg/kg and ketamine 1 mg/kg. We collected information including heart rate, pulse oxygen saturation, sedation onset time, exam time, recovery time, and adverse reactions. Stepwise logistic regression analyses were performed to analyze the risk factors for sedation failure.

RESULTS

Sedation was successful in 2212 patients (96%) and took effect in 15.7 (IQR: 10-23) min, while sedation failed in 92 patients. Cyanotic heart disease, history of sedation failure, history of congenital heart disease surgery, and fever were independent risk factors for sedation failure. Most of the patients in this study had an American Society of Anesthesiologists (ASA) grade of II to III, but no severe adverse reactions were observed.

CONCLUSION

Intranasal sedation with a combination of dexmedetomidine and ketamine is effective and appears to have an acceptable safety profile for young children during transthoracic echocardiography.

An open label pilot study of a dexmedetomidine-remifentanil-caudal anesthetic for infant lower abdominal/lower extremity surgery: The T REX pilot study

BACKGROUND

Concern over potential neurotoxicity of anesthetics has led to growing interest in prospective clinical trials using potentially less toxic anesthetic regimens, especially for prolonged anesthesia in infants. Preclinical studies suggest that dexmedetomidine may have a reduced neurotoxic profile compared to other conventional anesthetic regimens; however, coadministration with either anesthetic drugs (eg, remifentanil) and/or regional blockade is required to achieve adequate anesthesia for surgery. The feasibility of this pharmacological approach is unknown. The aim of this study was to determine the feasibility of a remifentanil/dexmedetomidine/neuraxial block technique in infants scheduled for surgery lasting longer than 2 hours.

METHODS

Sixty infants (age 1-12 months) were enrolled at seven centers over 18 months. A caudal local anesthetic block was placed after induction of anesthesia with sevoflurane. Next, an infusion of dexmedetomidine and remifentanil commenced, and the sevoflurane was discontinued. Three different protocols with escalating doses of dexmedetomidine and remifentanil were used.

RESULTS

One infant was excluded due to a protocol violation and consent was withdrawn prior to anesthesia in another. The caudal block was unsuccessful in two infants. Of the 56 infants who completed the protocol, 45 (80%) had at least one episode of hypertension (mean arterial pressure >80 mm Hg) and/or movement that required adjusting the anesthesia regimen. In the majority of these cases, the remifentanil and/or dexmedetomidine doses were increased although six infants required rescue 0.3% sevoflurane and one required a propofol bolus. Ten infants had at least one episode of mild hypotension (mean arterial pressure 40-50 mm Hg) and four had at least one episode of moderate hypotension (mean arterial pressure <40 mm Hg).

CONCLUSION

A dexmedetomidine/remifentanil neuraxial anesthetic regimen was effective in 87.5% of infants. These findings can be used as a foundation for designing larger trials that assess alternative anesthetic regimens for anesthetic neurotoxicity in infants.

Prolonged sedation in critically ill children: is dexmedetomidine a safe option for younger age? An off-label experience

BACKGROUND

Dexmedetomidine (DEX) is an alpha-2-adrenergic agonist, recently approved by Italian-Medicines-Agency for difficult sedation in pediatrics, but few data exist regarding prolonged infusions in critically-ill children, especially in younger ages. Aim of our study was to evaluate DEX use and safety for prolonged sedation in Pediatric Intensive Care Units (PICUs).

METHODS

Patients receiving DEX for ≥24 hours were retrospectively evaluated to analyze DEX indications, dosages, use of analgesics or sedatives, adverse events (AEs), withdrawal syndrome or delirium.

RESULTS

Forty-seven patients (median 0.7years) from nine PICUs were enrolled. Main indications were adjuvant for drugs sparing (59.6%) and for analgosedation weaning (36.2%). Median infusion duration was 82.0 hours (IQR 62.2-126.0), with dosages between 0.4 (IQR 0.2-0.5) and 0.8 mcg/kg/h (IQR 0.6-1.2). Fifty-nine-percent of patients received other sedatives, 83% other analgesics. Twenty-one-percent presented withdrawal syndrome, 4.2% delirium, none of them DEX-related. Forty-six-percent experienced a potentially-DEX-related AE. AEs were all hemodynamic, 14.9% requiring intervention but none DEX interruption. The median minimum and maximum dosages were significantly higher in patients with AEs (0.5 vs. 0.3,P=0.001; 1.0 vs. 0.7,P<0.001), without correlations with the infusion duration. AEs rate was higher in patients receiving benzodiazepines (P=0.020) or more than one analgesic (P=0.003) and in those presenting withdrawal syndrome (P<0.001).

CONCLUSIONS

DEX was confirmed as useful and relatively safe drug for prolonged sedation in critically-ill children, particularly in younger ages. Main AEs were cardiovascular, reversible, related with higher doses, with the concomitant use of benzodiazepines or multiple sedation drugs and with the presence of withdrawal syndrome.

Comparative Evaluation of Different Doses of Intravenous Dexmedetomidine on Hemodynamic Response during Laryngoscopy and Endotracheal Intubation in Geriatric Patients Undergoing Spine Surgeries: A Prospective, Double-Blind Study

BACKGROUND

Dexmedetomidine, a selective alpha 2 (α2)-adrenergic receptor agonist, has been used to blunt the hemodynamic response associated with laryngoscopy and tracheal intubation, which is a common concern for the anesthesiologist, especially in high-risk patients and geriatric age group.

AIM AND OBJECTIVES

The current study is to evaluate and compare the effects of different doses of dexmedetomidine in controlling hemodynamic response during tracheal intubation in geriatric patients.

MATERIALS AND METHODS

After getting approval from the Ethical Committee, 90 patients of the American Society of Anesthesiologist Physical Status Classes I and II, aged ≥60 years, were randomly assigned into three groups: Group I (normal saline, n = 30), Group II - dexmedetomidine (0.50 μg/kg, n = 30), and Group III - dexmedetomidine (1.00 μg/kg, n = 30). Dexmedetomidine was infused for 10 min before induction. Data were recorded as before infusion (T0), at the end of infusion (T1), before tracheal intubation (T2), at the moment of tracheal intubation (T3) 5 min after tracheal intubation (T4), and 10 min after tracheal intubation (T5). Modified observer's assessment of alertness/sedation scale score was observed at the time of T0 and T1. All statistical analyses were done using SPSS version 22.

RESULTS

Mean systolic blood pressure was statistically significantly (P < 0.05) more among Group I compared to Group II and III at T2, T3, and T4. Mean heart rate (HR) value was significantly (P < 0.05) more among Group I compared to Group III from T1 to T5, whereas there was no significant change in HR between Group I and Group II and at T4 and T5 h was comparable in Group II and Group III.

CONCLUSION

This study concluded that more acceptable hemodynamic changes were seen with 0.50 μg/kg dexmedetomidine when compared with 1.0 μg/kg dexmedetomidine during intubation. A lower dose besides being cost-effective is also free of side effects associated with the higher dose of 1 μg/kg dexmedetomidine.

Efficacy of different doses of dexmedetomidine as a rapid bolus for children: a double-blind, prospective, randomized study

Background

Dexmedetomidine (DEX), a highly sensitive α₂-adrenoceptor agonist that possesses anxiolytic, sedative, and analgesic effects, has been documented as a preventative and treatment for emergence agitation (EA). The therapeutic should be given as a loading dose that is infused during a 10 min period, but if a rapid bolus injection is deemed to be hemodynamically appropriate, it would be a more opportune route of administration. So we studied the efficacy of different doses of DEX as a rapid bolus for children to prevent and treat EA.

Methods

One hundred patients were enrolled and randomly divided into five groups: the control group (group D₁), the 0.25 μg/kg DEX group (group D₂), the 0.5 μg/kg DEX group (group D₃), the 0.75 μg/kg DEX group (group D₄), and the 1 μg/kg DEX group (group D₅). Heart rate (HR), mean blood pressure (MBP) and blood oxygen saturation (SaO₂) were recorded immediately before the study drug injection (baseline) and every minute for 5 min thereafter and at the time points of the skin cut and hernial sac pull. EA and pain were assessed in the post -anesthesia care unit, and any complementary medicine and adverse events were recorded too.

Results

The incidence of EA was significantly decreased in group D₄ and group D₅ compared with D₁.All groups exhibited similar baseline HR and MBP. After administered, HR and MBP were significantly decreased in all DEX group compared with group D_1.In groups D₃, D₄ and D₅, the minimal HR was decreased significantly compared with the groups D₁ and duration time of minimal HR significantly prolonged in group D₅, but no patient needed treatment. As the dosage increased, the recovery time was significantly prolonged. There were no significant differences in occurrence time of minimal HR, the incidence of complementary medicine and adverse events among groups.

Conclusion

Rapid intravenous injection (IV) bolus administration of 0.75 and 1.0 μg/kg of DEX could improve the recovery profile by reducing the incidence of EA in children. Although its use resulted in a transient decreases in HR and MBP, DEX was clinically well-tolerated in children.

Trial registration

No. ChiCTR-IPR-17010658. Registered 17 February 2017.

Beneficial effects of dexmedetomidine on early postoperative cognitive dysfunction in pediatric patients with tonsillectomy

According to clinical investigations, early postoperative cognitive dysfunction is the most common adverse event in pediatric patients after tonsillectomy. A previous study has indicated that dexmedetomidine (DEX) is an efficient drug for the treatment of postoperative cognitive dysfunction. However, the efficacy of DEX in alleviating early postoperative cognitive dysfunction in pediatric patients following tonsillectomy has remained elusive, which was therefore assessed in the present study. A total of 186 children presenting with cognitive dysfunction subsequent to tonsillectomy were recruited to analyze the efficacy of DEX. Patients were randomly divided into two groups and received intravenous treatment with DEX (n=112) or placebo (n=74). Duration of treatment, dose-limiting toxicities (DLT) and maximum tolerated dose (MTD) of DEX were evaluated in a preliminary experiment. The improvement of postoperative cognitive function in children with tonsillectomy was analyzed with a Mini-Mental State Examination (MMSE) following treatment with DEX. A 40-item quality of life (MONEX-40) questionnaire was used to assess the efficacy of DEX. The plasma levels of interleukin (IL)-6, IL-1, tumor necrosis factor (TNF)-α, superoxide dismutase (SOD), neuron-specific enolase (NSE), C-reactive protein (CRP), cortisol and melatonin were also analyzed. The preliminary experiment determined that the DLT was 10 mg/kg and the MTD was 15 mg/kg. In the major clinical trial, it was revealed that MMSE scores in the DEX treatment group were markedly improved, indicating that DEX had a beneficial effect in pediatric patients with early postoperative cognitive dysfunction after tonsillectomy. In addition, IL-1and TNF-α were downregulated, while IL-6 and SOD were upregulated in patients with cognitive dysfunction after treatment with DEX compared with those in the placebo group. Furthermore, DEX treatment markedly decreased the serum levels of CRP, NSE cortisol and melatonin, which are associated with the occurrence of postoperative cognitive dysfunction in pediatric patients following tonsillectomy. In conclusion, intravenous administration of DEX at a dose of 10 mg/kg improves postoperative cognitive function in pediatric patients with tonsillectomy by decreasing the serum levels of inflammatory factors and stress-associated signaling molecules. Trial registration no. QLSDHOS0200810102C (Qilu Hospital of Shandong University, Jinan, China).

Conscious sedation with dexmedetomidine for implantation of a phrenic nerve stimulator in a pediatric case of late-onset congenital central hypoventilation syndrome

Patients with congenital central hypoventilation syndrome (CCHS) develop alveolar hypoventilation resulting from a failure of central ventilatory control. Late-onset CCHS (LO-CCHS), which may be precipitated by severe respiratory infection or exposure to sedatives or general anesthesia, presents after the neonatal period. Since CCHS patients require lifelong mechanical-assisted ventilation, in western countries, diaphragm pacing is used to provide adequate alveolar ventilation and oxygenation during rest and daily activities. The main anesthesia-related concern regarding CCHS is postoperative respiratory failure or apnea, and anesthetic agents should be minimized to avoid further respiratory depression after surgery. A 5-year-old girl with LO-CCHS was referred to our hospital for implantation of a phrenic nerve stimulator for diaphragm pacing. Respiratory infection triggered the need for permanent nocturnal ventilator support at age 3 years and tracheotomy was performed at age 4 years. Repeated self-dislodgement of the ventilator tube led to hypoxic ischemic encephalopathy. The patient was thought to require mechanical ventilation under minimum sedation and pain management during the early postoperative period. The co-administration of dexmedetomidine and morphine provided effective conscious sedation with protection of the surgical site and without adverse events. She was discharged from the intensive care unit with a home ventilator at 3 days post-operation.

Therapeutic Efficacy of Two Different Doses of Dexmedetomidine on the Hemodynamic Response to Intubation, the Intubating Conditions, and the Effect on the Induction Dose of Propofol: A Randomized, Double-Blind, Placebo-Controlled Study

Context:

The hemodynamic response associated with laryngoscopy and tracheal intubation is a common concern for the anesthesiologist, especially in high-risk patients. The use of dexmedetomidine has found favor in obtunding this response, in addition to providing better intubating conditions and reducing the dose of other anesthetic drugs. Most of the current literature states a loading dose of 1 μg/kg dexmedetomidine to be superior to lower doses in this regard. However, using a lower dose may be advantageous by reducing incidence of adverse effects such as hypotension and bradycardia which are likelier with the use of higher dose, in addition to being more cost-effective.

Aims:

The aim of the study was (1) to evaluate and compare the effect of loading doses of 1 μg/kg and 0.5 μg/kg dexmedetomidine on attenuation of hemodynamic response to laryngoscopy and intubation and (2) to evaluate the efficacy of dexmedetomidine in reducing the induction dose of propofol for achieving better intubating conditions.

Materials and Methods:

A randomized, double-blind, placebo-controlled study was planned on ninety American Society of Anesthesiologists I and II patients scheduled for elective surgery under general anesthesia. Patients were divided into three groups. Two groups received different loading doses of dexmedetomidine infusion before induction and the third group was a control group. The induction dose of propofol required to abolish the verbal response was noted and compared in all the three groups. All patients were assessed for the intubating conditions and hemodynamic response.

Statistical Analysis:

Nonparametric data were compared using the Chi-square test and parametric data were compared using Student's t-test using SPSS 16.0 software.

Results:

Both the loading doses of 1 μg/kg and 0.5 μg/kg dexmedetomidine were equally effective in reducing the induction dose of propofol, improving the intubating conditions and blunting the hemodynamic response to laryngoscopy and intubation. The incidence of adverse effects such as hypotension and bradycardia was lesser with the loading dose of 0.5 μg/kg.

Conclusions:

Dexmedetomidine when used as infusion in the loading dose of 0.5 μg/kg is therapeutically as effective as when used in the dose of 1.0 μg/kg not only in reducing the induction dose of propofol but also in providing good intubating conditions and blunting the hemodynamic response to intubation. A lower dose is associated with a lesser incidence of adverse effects such as hypotension and bradycardia.

Prolonged Dexmedetomidine Infusion and Drug Withdrawal In Critically Ill Children

OBJECTIVE

To characterise the incidence, symptoms and risk factors for withdrawal associated with prolonged dexmedetomidine infusion in paediatric critically ill patients.

METHODS

Retrospective chart review in the paediatric intensive care unit and the cardiac critical care unit of a single tertiary children's hospital. Patients up to 18 years old, who received dexmedetomidine for longer than 48 hours were included.

RESULTS

A total of 52 patients accounted for 68 unique dexmedetomidine treatment courses of more than 48 hours. We identified 24 separate episodes of withdrawal in the 68 dexmedetomidine courses (incidence 35%). Of these episodes 38% occurred in patients who were weaned from dexmedetomidine alone while the remaining occurred in patients who had concurrent weans of opioids and/or benzodiazepines. Most common symptoms were agitation, fever, vomiting/retching, loose stools and decreased sleep. The symptoms occurred during the latter part of the wean or after discontinuation of dexmedetomidine. A cumulative dose of dexmedetomidine of 107 mcg/kg prior to initiation of wean was more likely associated with withdrawal (this equates to a dexmedetomidine infusion running at 1 mcg/kg/hr over 4 days). Duration of opioid use was an additional risk factor for withdrawal. The use of clonidine, as a transition from dexmedetomidine, did not protect against withdrawal (p = 1).

CONCLUSIONS

A withdrawal syndrome may occur after prolonged infusion of dexmedetomidine. As all our patients were also exposed to opioids this may be affected by the duration of opioid use. We identified a cumulative dose of 107 micrograms/kg of dexmedetomidine beyond which withdrawal symptoms were more likely (which equates to 4 days of use at a dose of 1 mcg/kg/hr). A protocol for weaning should be considered in this circumstance.

Dexmedetomidine as an adjuvant for perioperative pain management in adolescents undergoing bariatric surgery: An observational cohort study

BACKGROUND

The anesthetic management of adolescents undergoing bariatric surgery presents a number of challenges, including increased risk of postoperative opioid-related respiratory depression. These patients could benefit from adjunctive analgesics with opioid-sparring effects to optimize perioperative pain control. Dexmedetomidine, a selective α2-adrenoreceptor agonist, has sedative and analgesic properties with no respiratory depressant effects.

OBJECTIVE

To determine the effect of intraoperative dexmedetomidine on opioid requirement and perioperative pain management in obese adolescents undergoing bariatric surgery.

METHODS

An observational study of 26 consecutive patients treated with and without dexmedetomidine during the intraoperative period was conducted. The dexmedetomidine treated patients received a loading dose over 30min and a continuous infusion thereafter. The standard group represented patients who received an institutional standard anesthetic without dexmedetomidine. The primary outcome was total perioperative intravenous morphine equivalent (MEq). We also examined reported pain scores during the perioperative period.

RESULTS

While there were no significant differences in age, height and weight category, there were imbalances on race distribution between the two groups. Both groups received similar doses of ketorolac and acetaminophen perioperatively. Overall, during 48h postoperatively, the dexmedetomidine group received significantly less total MEq administration compared with the standard group. Three patients in the dexmedetomidine group required ephedrine to treat an episode of hypotension.

DISCUSSION

These results suggest that the use of dexmedetomidine during bariatric surgery in the morbidly obese adolescent population is associated with decreased opioid utilization during the perioperative period. Future randomized studies will determine the role of dexmedetomidine in the pain management of obese adolescents undergoing bariatric surgery.

STUDY TYPE

Therapeutic, Level III.

Sedation and analgesia for procedures in the pediatric emergency room

OBJECTIVE

Children and adolescents often require sedation and analgesia in emergency situations. With the emergence of new therapeutic options, the obsolescence of others, and recent discoveries regarding already known drugs, it became necessary to review the literature in this area.

DATA SOURCES

Non-systematic review in the PubMed database of studies published up to December 2016, including original articles, review articles, systematic reviews, and meta-analyses. References from textbooks, publications from regulatory agencies, and articles cited in reviews and meta-analyses through active search were also included.

DATA SYNTHESIS

Based on current literature, the concepts of sedation and analgesia, the necessary care with the patient before, during, and after sedoanalgesia, and indications related to the appropriate choice of drugs according to the procedure to be performed and their safety profiles are presented.

CONCLUSIONS

The use of sedoanalgesia protocols in procedures in the pediatric emergency room should guide the professional in the choice of medication, the appropriate material, and in the evaluation of discharge criteria, thus assuring quality in care.

Pharmacologic Considerations for Pediatric Sedation and Anesthesia Outside the Operating Room: A Review for Anesthesia and Non-Anesthesia Providers

Understanding the pharmacologic options for pediatric sedation outside the operating room will allow practitioners to formulate an ideal anesthetic plan, allaying anxiety and achieving optimal immobilization while ensuring rapid and efficient recovery. The authors identified relevant medical literature by searching PubMed, MEDLINE, Embase, Scopus, Web of Science, and Google Scholar databases for English language publications covering a period from 1984 to 2017. Search terms included pediatric anesthesia, pediatric sedation, non-operating room sedation, sedation safety, and pharmacology. As a narrative review of common sedation/anesthesia options, the authors elected to focus on studies, reviews, and case reports that show clinical relevance to modern day sedation/anesthesia practice. A variety of pharmacologic agents are available for sedation/anesthesia in pediatrics, including midazolam, fentanyl, ketamine, dexmedetomidine, etomidate, and propofol. Dosing ranges reported are a combination of what is discussed in the reviewed literature and text books along with personal recommendations based on our own practice. Several reports reveal that ketofol (a combination of ketamine and propofol) is quite popular for short, painful procedures. Fospropofol is a newer-generation propofol that may confer advantages over regular propofol. Remimazolam combines the pharmacologic effects of remifentanil and midazolam. A variety of etomidate derivatives such as methoxycarbonyl-etomidate, carboetomidate, methoxycarbonyl-carboetomidate, and cyclopropyl-methoxycarbonyl metomidate are in development stages. The use of nitrous oxide as a mild sedative, analgesic, and amnestic agent is gaining popularity, especially in the ambulatory setting. Utilizing a dedicated and experienced team to provide sedation enhances safety. Furthermore, limiting sedation plans to single-agent pharmacy appears to be safer than using multi-agent plans.

Dexmedetomidine for Sedation During Noninvasive Ventilation in Pediatric Patients

OBJECTIVES

To describe the use of dexmedetomidine for sedation in a large cohort of nonintubated children with acute respiratory insufficiency receiving noninvasive ventilatory support.

DESIGN

Single-center, retrospective, observational cohort study.

SETTING

A large quaternary-care PICU.

PATIENTS

The study cohort included 202 children receiving noninvasive ventilatory and a dexmedetomidine infusion within 48 hours of PICU admission over a 6-month period.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The primary respiratory diagnoses in the cohort (median age, 2 yr) included status asthmaticus (60%) and bronchiolitis (29%). Dexmedetomidine was infused for a median of 35 hours with a median hourly dose across the patient cohort of 0.61 μg/kg/hr (range, 0.4-0.8 μg/kg/hr). The target sedation level was achieved in 168 patients (83%) in the cohort for greater than or equal to 80% of the recorded values over the entire noninvasive ventilatory course, with dexmedetomidine as the only continuously administered sedative agent. While vital signs were frequently abnormal relative to age-based norms, clinical interventions were needed rarely to treat bradycardia (13%), hypotension (20%), and hypopnea (5%). The most frequently used of these interventions was a dexmedetomidine dose reduction, fluid bolus, and titration of noninvasive ventilatory support. Five patients (2.5%) required endotracheal intubation: three due to progression of their respiratory illness, one with septic shock, and one with apnea requiring resuscitation. In 194 of 202 patients (96%), the outcome of the noninvasive ventilatory course was successful with the patient being weaned from noninvasive respiratory support to nasal cannula or room air.

CONCLUSIONS

Dexmedetomidine was often effective as a single continuous sedative infusion during pediatric noninvasive ventilatory. Cardiorespiratory events associated with its use were typically mild and/or reversible with dose reduction, fluid administration, and/or noninvasive ventilatory titration. Prospective studies comparing dexmedetomidine with other agents in this setting are warranted.

A prospective randomized controlled double-blind trial to assess the effects of dexmedetomidine during cleft palate surgery

Background

We investigated whether the intraoperative administration of dexmedetomidine would attenuate the profound sympathoadrenal response associated with cleft palate (CP) surgery.

Methods

Sixty children aged 6 months to 12 years undergoing CP surgery under general anesthesia were randomly assigned to the control (C) or dexmedetomidine (D) groups. Group C received benzodiazepine (0.05 mg/kg midazolam followed by infusion of normal saline) fentanyl isoflurane anesthesia, and Group D received dexmedetomidine (loading 1 µg/kg followed by infusion of 0.5 µg/kg/h) fentanyl isoflurane anesthesia. Heart rate (HR), mean blood pressure (MBP), intraoperative fentanyl and isoflurane requirements, recovery scores, emergence agitation, pain scores, time and requirement of rescue analgesic, and surgeon satisfaction were noted.

Results

Intraoperative HR and MBP in Group D were significantly lower than the corresponding values in Group C (P < 0.001). HR decreased up to 16% in Group D. By contrast, HR increased up to 20% in Group C. Group D had comparable MBP to its baseline, whereas Group C had higher MBP until extubation (P = 0.015). Two children in Group D developed bradycardia and hypotension, which was successfully treated. The fentanyl and isoflurane requirements decreased by 43% and 30%, respectively, in Group D patients compared to those in Group C (P < 0.001). Group D had lower pain scores and less emergence agitation (P < 0.001). Time until requirement of first rescue analgesic was longer in Group D than that in Group C (P < 0.001). Surgeon satisfaction was higher in Group D than that in Group C.

Conclusions

Intravenous dexmedetomidine during CP surgery attenuated hemodynamic responses with excellent surgeon satisfaction. Close monitoring of hemodynamics is recommended.

The Effect of Perineural Administration of Dexmedetomidine on Narcotic Consumption and Pain Intensity in Patients Undergoing Femoral Shaft Fracture Surgery; A Randomized Single-Blind Clinical Trial

Dexmedetomidine is a selective α-2 adrenoceptor agonist with anxiolytic, sedative, and analgesic properties that prolongs analgesia and decreases opioid-related side effects when used in neuraxial and perineural areas as a local anesthetics adjuvant. The current study was designed to evaluate the effects of a single perineural administration of dexmedetomidine without local anesthetics on narcotic consumption and pain intensity in patients with femoral shaft fractures undergoing surgery. This prospective randomized single-blind clinical trial was conducted in patients undergoing femoral fracture shaft surgery. Based on block permuted randomization, the patients were randomly divided into intervention and control groups. The intervention group received 100µg dexmedetomidine, for a femoral nerve block without any local anesthetics. Total intraoperative opioid consumption, postoperative opioid consumption, visual analogue score (VAS) for pain, and hemodynamic parameters were recorded and compared. Finally the data from 60 patients with a mean age of 30.4±12.3 were analyzed (90% male). There were no significant differences between the baseline characteristics of the two groups (p>0.05). The mean total consumption of narcotics was reduced during induction and maintenance of anesthesia in the intervention group (p<0.05). The amount of postoperative narcotics required showed a significant difference in the intervention group compared with the control group (p<0.05). It is likely that perineural administration of dexmedetomidine significantly not only reduced intra and postoperative narcotic requirement but also decreased postoperative pain intensity in patients undergoing femoral shaft surgery. Femoral blockade by dexmedetomidine can provide excellent analgesia while minimizing the side-effects of opioids.

A multinational, drug utilization study to investigate the use of dexmedetomidine (Dexdor®) in clinical practice in the EU

Aims

Dexmedetomidine (dexdor®) is approved in the European Union (EU) for sedation of adults in the intensive care unit (ICU). The present observational, retrospective study was requested by the European Medicines Agency to investigate dexmedetomidine use in clinical practice, with a particular focus on off‐label use, including the paediatric population.

Methods

Study countries and sites were chosen from those with highest dexmedetomidine use, based on sales. Site selection (blind) was conducted by a multispecialist, independent group. Anonymized data on demographics, treatment indication, dexmedetomidine dosing, concomitant medications and treatment effectiveness were collected retrospectively from records of all dexmedetomidine‐treated patients at the site during the enrolment period. Informed consent was waived, to avoid influencing the prescribing of dexmedetomidine. Recruitment was completed within 18 months of first site initiation.

Results

Data from 2000 patients were collected from 16 hospitals in four EU countries (Finland 750, Poland 505, Germany 470, Austria 275). The median age was 62 years, with more males (70.2%) than females. Dexmedetomidine was primarily used in the adult ICU (86.0%) for ICU sedation (78.6%) and mostly dosed according the product label. The intended sedative effect was obtained in 84.9% of administrations. Paediatric use (5.9% of patients, mostly in Austria and Finland) occurred mainly in the adult or paediatric ICU (75.6%) for sedation (67.2%).

Conclusions

Overall, most patients were treated with dexmedetomidine according to the product labelling. Use in children was limited but significant and similar in scope to that in adults. Administrations not fully according to the product labelling usually occurred in an ICU environment and reflected extensively investigated clinical uses of dexmedetomidine.

Clonidine for sedation and analgesia for neonates receiving mechanical ventilation

BACKGROUND

Although routine administration of pharmacologic sedation or analgesia during mechanical ventilation in preterm neonates is not recommended, its use in clinical practice remains common. Alpha-2 agonists, mainly clonidine and dexmedetomidine, are used as adjunctive (or alternative) sedative agents alongside opioids and benzodiazepines. Clonidine has not been systematically assessed for use in neonatal sedation during ventilation.

OBJECTIVES

To assess whether clonidine administered to term and preterm newborn infants receiving mechanical ventilation reduces morbidity and mortality rates. To compare the intervention versus placebo, no treatment, and dexmedetomidine; and to assess the safety of clonidine infusion for potential harms.To perform subgroup analyses according to gestational age; birth weight; administration method (infusion or bolus therapy); dose, duration, and route of clonidine administration; and pharmacologic sedation as a co-intervention.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review Group to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 12) in the Cochrane Library, MEDLINE via PubMed (1966 to January 10, 2017), Embase (1980 to January 10, 2017), and the Cumulative Index to Nursing and Allied Health Literature (CINAHL; 1982 to January 10, 2017). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomized controlled trials and quasi-randomized trials.

SELECTION CRITERIA

We searched for randomized controlled trials, quasi-randomized controlled trials, and cluster trials comparing clonidine versus placebo, no treatment, or dexmedetomidine administered to term and preterm newborns receiving mechanical ventilation via an endotracheal tube.

DATA COLLECTION AND ANALYSIS

For the included trial, two review authors independently extracted data (e.g. number of participants, birth weight, gestational age, all-cause death during initial hospitalization, duration of respiratory support, sedation scale, duration of hospital stay) and assessed risk of bias (e.g. adequacy of randomization, blinding, completeness of follow-up). This review considered primary outcomes of all-cause neonatal death, all-cause death during initial hospitalization, and duration of mechanical ventilation in days.

MAIN RESULTS

One trial, which included 112 infants, met the inclusion criteria for this review. Term newborn infants on mechanical ventilation with the need for continuous analgesia and sedation with fentanyl and midazolam were eligible for enrollment during the first 96 hours of ventilation. Study authors administered clonidine 1 μg/kg/h or placebo on day 4 after intubation.We found no differences between the two groups in all-cause death during hospitalization (risk ratio [RR] 0.69, 95% confidence interval [CI] 0.12 to 3.98). The quality of the evidence supporting these findings is low owing to imprecision of the estimates (one study; few events). The median (interquartile range) duration of mechanical ventilation was 7.1 days (5.7 to 9.1 days) in the clonidine group and 5.8 days (4.9 to 7.9 days) in the placebo group, respectively (P = 0.070). Among secondary outcomes, we found no differences in terms of duration of stay in the intensive care unit. Sedation scale values (COMFORT) and analgesia scores (Hartwig) during the first 72 hours of infusion of study medication were lower in the clonidine group than in the placebo group.

AUTHORS' CONCLUSIONS

At present, evidence is insufficient to show the efficacy and safety of clonidine for sedation and analgesia in term and preterm newborn infants receiving mechanical ventilation.

Comparison of Dexmedetomidine and Fentanyl as an Adjuvant to Ropivacaine for Postoperative Epidural Analgesia in Pediatric Orthopedic Surgery

PURPOSE

Opioids are commonly used as an epidural adjuvant to local anesthetics, but are associated with potentially serious side effects, such as respiratory depression. The aim of this study was to compare the efficacy and safety of dexmedetomidine with that of fentanyl as an adjuvant to epidural ropivacaine in pediatric orthopedic surgery.

MATERIALS AND METHODS

This study enrolled 60 children (3-12 years old) scheduled for orthopedic surgery of the lower extremities and lumbar epidural patient-controlled analgesia (PCA). Children received either dexmedetomidine (1 μg/kg) or fentanyl (1 μg/kg) along with 0.2% ropivacaine (0.2 mL/kg) via an epidural catheter at 30 minutes before the end of surgery. Postoperatively, the children were observed for ropivacaine consumption via epidural PCA, postoperative pain intensity, need for rescue analgesics, emergence agitation, and other adverse effects.

RESULTS

The mean dose of bolus epidural ropivacaine was significantly lower within the first 6 h after surgery in the dexmedetomidine group, compared with the fentanyl group (0.029±0.030 mg/kg/h vs. 0.053±0.039 mg/kg/h, p=0.012). The median pain score at postoperative 6 h was also lower in the dexmedetomidine group, compared to the fentanyl group [0 (0-1.0) vs. 1.0 (0-3.0), p=0.039]. However, there was no difference in the need for rescue analgesia throughout the study period between groups.

CONCLUSION

The use of dexmedetomidine as an epidural adjuvant had a significantly greater analgesic and local anesthetic-sparing effect, compared to fentanyl, in the early postoperative period in children undergoing major orthopedic lower extremity surgery.

Imidazoline 1 receptor activation preserves respiratory drive in spontaneously breathing newborn rats during dexmedetomidine administration

BACKGROUND

Dexmedetomidine is an alpha-2 (α₂ ) adrenoceptor and imidazoline 1 (I₁ ) receptor agonist that provides sedation without loss of respiratory drive.

AIMS

The aim of this study was to elucidate the involvement of α₂ -adrenoceptor and I₁ receptor in the cardiorespiratory changes induced by dexmedetomidine in spontaneously breathing newborn rats.

METHODS

An abdominal catheter to administer drugs and three subcutaneous electrodes to record electrocardiographic data were inserted into 2- to 5-day-old Wistar rats under isoflurane anesthesia. In individual chambers, each rat was intraperitoneally administered dexmedetomidine (50 μg·kg^-1 ) followed 5 min later by normal saline or 1, 5, or 10 mg·kg^-1 atipamezole (selective α₂ -adrenoceptor antagonist) or efaroxan (α₂ -adrenoceptor/I₁ receptor antagonist). Cardiorespiratory indices were recorded before and after drug administration.

RESULTS

The administration of dexmedetomidine alone resulted in significant changes to most of the cardiorespiratory indices examined. The addition of 5 or 10 mg·kg^-1 atipamezole or 1 mg·kg^-1 efaroxan completely ameliorated the dexmedetomidine-associated reduction in heart rate (HR). The addition of 1 mg·kg^-1 atipamezole or 1 or 5 mg·kg^-1 efaroxan completely ameliorated the dexmedetomidine-associated reduction in respiratory frequency. Mean inspiratory flow (V_T /T_I ; V_T is tidal volume and T_I is inspiratory time), which is an index of respiratory drive, was not significantly affected by the administration of dexmedetomidine alone (P = 0.273) or dexmedetomidine + atipamezole (P = 0.605, 0.153, 0.138 for 1, 5, 10 mg·kg^-1 atipamezole, respectively); however, it was significantly decreased after the administration of dexmedetomidine + efaroxan (P = 0.029, <0.001, <0.001 for 1, 5, 10 mg·kg^-1 efaroxan, respectively).

CONCLUSIONS

Our results suggest that in newborn rats undergoing dexmedetomidine sedation, the α₂ -adrenoceptor, but not I₁ receptor, is involved in the regulation of HR and respiratory frequency, and that activation of the I₁ receptor plays a major role in the maintenance of respiratory drive.