Dexmedetomidine: applications in pediatric critical care and pediatric anesthesiology

Sinus Arrest Related to Dexmedetomidine Infusion in an Infant; a Case Report and Review of Current Literature

Background: Dexmedetomidine, an alpha 2 agonist, has emerged as a desirable sedative agent in the pediatric intensive care unit due to its minimal effect on respiratory status and reduction in delirium. Bradycardia and hypotension are common side effects, however there are emerging reports of more serious cardiovascular events, including sinus arrest and asystole. These case reports have been attributed to high vagal tone or underlying cardiac conduction dysfunction. Objectives: To describe the development of sinus arrest during sedation with dexmedetomidine in a patient without clinical features of high vagal tone, underlying cardiac conduction dysfunction, or intervening episodes of bradycardia. Case Presentation: An 11 month-old patient requiring sedation during mechanical ventilation for acute respiratory failure secondary to Adenovirus. To facilitate sedation, a dexmedetomidine infusion was initiated at .5 mcg/kg/hr and increased to maximum 1 mcg/kg/hr. Within 8 hours of initiating therapy, the patient had three episodes of sinus arrest. There was no intervening bradycardia between episodes and no further episodes occurred following discontinuation of dexmedetomidine. The patient did not have any clinical features associated with high vagal tone or underlying cardiac conduction dysfunction. Conclusions: As result of these findings, understanding risk factors for bradycardia, or more serious hemodynamic instability with dexmedetomidine infusions, is important to help identify high risk patients and weigh the associated risks and benefits of its administration.

Dexmedetomidine administration as a possible cognitive enhancer through increasing the level of brain-derived neurotrophic factors in surgical patients: a systematic review and meta-analysis

OBJECTIVE

This meta-analysis aimed to investigate the effect of dexmedetomidine on brain-derived neurotrophic factor (BDNF) levels in individuals undergoing various medical procedures. We systematically searched electronic databases and manually identified relevant articles to assess the impact of dexmedetomidine on BDNF levels in surgical patients.

METHODS

A comprehensive literature search was conducted in PubMed, Scopus, Embase, and Web of Science databases with no language restrictions. Studies that examined the effects of dexmedetomidine administration on BDNF levels in surgical patients were included.

RESULTS

The overall analysis revealed a statistically significant increase in BDNF levels in individuals receiving dexmedetomidine compared to controls (Standardized Mean Difference SMD = 1.65, 95% CI: 1.02 to 2.28; I2: 89%). Subgroup analyses based on the anesthesia method (p < 0.01), and the type of surgery (p < 0.01) showed significant between-group differences (Fig. 3). The results of the sensitivity analyses indicated that individual studies did not significantly affect the overall results.

CONCLUSION

This meta-analysis indicates that dexmedetomidine administration is associated with a significant increase in BDNF levels in individuals undergoing surgical procedures. These findings highlight the potential role of dexmedetomidine in modulating BDNF levels, which may have implications for optimizing perioperative neuroprotective strategies and improving patient outcomes.

Enhancing ketamine anesthesia with midazolam and fentanyl for children's ear surgery: a prospective randomized study

BACKGROUND

Myringotomy with tympanostomy tube insertion (MTI) is a superficial surgical procedure used to prevent hearing loss in children with serous otitis media. Intravenous anesthesia, often ketamine, is preferred for this procedure because of its ability to induce sedation without compromising airway reflexes. However, ketamine alone may be insufficient and potentially lead to spontaneous movement during surgery. This study evaluated the effectiveness of midazolam and fentanyl as adjuvants to ketamine in reducing spontaneous movement during MTI and enhancing the quality of recovery.

METHODS

This study involved two groups of 30 patients each: one group received intravenous ketamine (1.5 mg/kg) with an equal volume of normal saline (K group), while the other received a combination of midazolam, fentanyl, and ketamine (0.05 mg/kg, 1 μg/kg, and 1.5 mg/kg, respectively; MFK group). We assessed side effects, intraoperative patient movement, surgeon satisfaction, and emergence agitation scores.

RESULTS

The MFK group exhibited significantly lower scores for patient movement (p<0.01) and emergence agitation (p<0.01) and markedly higher surgeon satisfaction scores (p<0.01) than the K group.

CONCLUSION

Administering a midazolam-fentanyl-ketamine combination effectively reduced spontaneous movement during surgery and emergence agitation during recovery without prolonging discharge times in children undergoing MTI.

Effectiveness and Safety of Dexmedetomidine in Neonates With Hypoxic Ischemic Encephalopathy Undergoing Therapeutic Hypothermia

OBJECTIVE

The objective of this study was to evaluate and compare the effectiveness and safety of dexmedetomidine as monotherapy between neonates with mild hypoxic ischemic encephalopathy (HIE) and moderate to severe HIE treated with therapeutic hypothermia (TH).

METHODS

This retrospective study included neonates of gestational age ≥36 weeks with a diagnosis of HIE and undergoing TH between January 2014 and December 2021. Patients were included if they received at least 6 hours of continuous sedation with dexmedetomidine. Baseline characteristics, dose and duration of medication, adverse events, liver and kidney function tests, and hospital course were reviewed.

RESULTS

Of the 97 neonates included, 46 had mild, 42 had moderate, and 9 had severe HIE. Dexmedetomidine was initiated at a median 5 hours of life, and the median infusion duration was 77 (46-87) hours. Fifty-two (53.6%) required at least 1 breakthrough opioid or sedative during the first 24 hours of dexmedetomidine infusion. Overall, 40 patients (41.2%) had at least 1 bradycardia episode with heart rate <80 beats/min and 14 patients (14.4%) had heart rate <70 beats/min. Hypotension was experienced by 7 patients (7.2%). Fifty-two patients (53.6%) were intubated in the delivery room and 33/52 (63.5%) were extubated on day of life 1 during dexmedetomidine infusion.

CONCLUSIONS

Dexmedetomidine as monotherapy was effective and safe sedation for infants with HIE undergoing hypothermia. The most common side effect of dexmedetomidine was bradycardia. -Dexmedetomidine may be considered as first and single agent for neonates with HIE undergoing TH.

Melatonin vs. dexmedetomidine for sleep induction in children before electroencephalography

Background and objectives

In children requiring electroencephalography (EEG), sleep recording can provide crucial information. As EEG recordings during spontaneous sleep are not always possible, pharmacological sleep-inducing agents are sometimes required. The aim of the study was to evaluate safety and efficacy of melatonin (Mel) and dexmedetomidine (Dex; intranasal and sublingual application) for sleep induction prior to EEG.

Methods

In this prospective randomized study, 156 consecutive patients aged 1-19 years were enrolled and randomized by draw into melatonin group (Mel; n = 54; dose: 0.1 mg/kg), dexmedetomidine (Dex) sublingual group (DexL; n = 51; dose: 3 mcg/kg) or dexmedetomidine intranasal group (DexN; n = 51; dose: 3 mcg/kg). We compared the groups in several parameters regarding efficacy and safety and also carried out a separate analysis for a subgroup of patients with complex behavioral problems.

Results

Sleep was achieved in 93.6% of participants after the first application of the drug and in 99.4% after the application of another if needed. Mel was effective as the first drug in 83.3% and Dex in 99.0% (p < 0.001); in the subgroup of patients with complex developmental problems Mel was effective in 73.4% and Dex in 100% (p < 0.001). The patients fell asleep faster after intranasal application of Dex than after sublingual application (p = 0.006). None of the patients had respiratory depression, bradycardia, desaturation, or hypotension.

Conclusions

Mel and Dex are both safe for sleep induction prior to EEG recording in children. Dex is more effective compared to Mel in inducing sleep, also in the subgroup of children with complex behavioral problems.

Clinical Trial Registration

Dexmedetomidine and Melatonin for Sleep Induction for EEG in Children, NCT04665453.

The Median Effective Dose of Dexmedetomidine for the Inhibition of Emergence Delirium in Preschool Children Undergoing Tonsillectomy and/or Adenoidectomy: A Retrospective Dose-response Trial

The incidence of emergence delirium (ED) is higher in preschool children undergoing tonsillectomy and/or adenoidectomy. The purpose of this study was to determine the median effective dose (ED50) of dexmedetomidine (DEX) for the inhibition of ED in preschool children by using probit regression analysis. A total of 140 anesthesia records were retrieved and divided into seven groups based on the infusion rate of DEX: .2, .25, .3, .35, .4, .45, and .5 μg·kg-1·h-1. The Pediatric Anesthesia Emergence Delirium Scale (PAEDS) was used to assess ED in preschool children, and ED was defined as a PAEDS score ≥ 10. Probit regression analysis revealed that the ED50 and ED95 of DEX were .31 μg·kg-1·h-1 (95% CI: .29-.35) and .48 μg·kg-1·h-1 (95% CI: .44-.56), respectively. Probit(p) = -2.84 + 9.28 × ln (Dose), (χ2 = 1.925, P = .859). The PAEDS score was significantly increased in the ED group, and the rate of bradycardia was significantly decreased in the ED group compared with the without ED group (27.3% vs 54.1%, P = .02). DEX can effectively inhibit the ED in preschool children undergoing tonsillectomy and/or adenoidectomy, however, bradycardia was the main complication.

Anesthesia, the developing brain, and dexmedetomidine for neuroprotection

Anesthesia-induced neurotoxicity is a set of unfavorable adverse effects on central or peripheral nervous systems associated with administration of anesthesia. Several animal model studies from the early 2000's, from rodents to non-human primates, have shown that general anesthetics cause neuroapoptosis and impairment in neurodevelopment. It has been difficult to translate this evidence to clinical practice. However, some studies suggest lasting behavioral effects in humans due to early anesthesia exposure. Dexmedetomidine is a sedative and analgesic with agonist activities on the alpha-2 (ɑ₂) adrenoceptors as well as imidazoline type 2 (I2) receptors, allowing it to affect intracellular signaling and modulate cellular processes. In addition to being easily delivered, distributed, and eliminated from the body, dexmedetomidine stands out for its ability to offer neuroprotection against apoptosis, ischemia, and inflammation while preserving neuroplasticity, as demonstrated through many animal studies. This property puts dexmedetomidine in the unique position as an anesthetic that may circumvent the neurotoxicity potentially associated with anesthesia.

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

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

Asystole in 2 Pediatric Patients During Dexmedetomidine Infusion

INTRODUCTION

Bradycardia is a known side effect of dexmedetomidine. Reports of sinus pauses or asystole, however, are rare. We present 2 cases of pediatric patients who developed asystole on a dexmedetomidine infusion.

SUMMARY OF CASES

An 8-week-old male with RSV bronchiolitis and acute hypoxemic respiratory failure was started on dexmedetomidine for sedation at 0.2 mcg/kg/h with a maximum dose of 0.7mcg/kg/h. On Hospital day (HD) 4, on dexmedetomidine at 0.7 mcg/kg/h, he developed intermittent episodes of bradycardia with heart rates in the 60 s. Echocardiogram on HD 6 showed normal function. On HD 7, he began having periods of asystole lasting up to 6 seconds. Dexmedetomidine was discontinued, with the resolution of episodes of asystole after 6 hours. A 27-month-old male with a congenital left diaphragmatic hernia and pulmonary hypertension who had been weaned off sildenafil 6 months earlier underwent re-repair of left diaphragmatic hernia. Postoperatively he remained intubated and paralyzed. Dexmedetomidine was started at 0.3 mcg/kg/h for sedation, with a maximum dose of 1.2 mcg/kg/h. An echocardiogram on HD 3 showed good function with mild to moderate pulmonary hypertension. That evening, with dexmedetomidine at 1.1 mcg/kg/h, he developed a 15 second period of asystole requiring CPR. Dexmedetomidine was discontinued, and he was started on a midazolam infusion with no further episodes.

DISCUSSION

Both cases occurred in patients without cardiac conduction defects or on negative chronotropic or sympatholytic medications that have been associated with dexmedetomidine-induced asystole. We hypothesize that both episodes of asystole were due to increased patient-related vagal tone exacerbated by dexmedetomidine.

A retrospective analysis of dexmedetomidine and morphine in the fast-track and ultra-fast-track extubation protocol after congenital cardiac surgery

BACKGROUND AND AIM OF THE STUDY

After congenital cardiac surgery, the duration of mechanical ventilation (MV) is related to the clinical status, type of operation, and the sedative-analgesic agents used postoperatively. This study aims to examine the effects of dexmedetomidine and morphine on the fast-track extubation (FTE) and ultra-fast-track extubation (UFTE) protocol after congenital cardiac surgery.

METHODS

A total of 251 pediatric patients were divided into two groups: 118 patients in the morphine group (Group M) and 133 patients in the dexmedetomidine group (Group D). We retrospectively reviewed medical data including hemodynamic parameters, duration of MV and cardiovascular intensive care unit (CICU), additional sedative/analgesic requirement, adverse events, the need for reintubation, and noninvasive MV, sedation, and pain scores.

RESULTS

The mean mechanical ventilation duration of Group D was significantly shorter than Group M (3.74 ± 0.83 h in Group D, 5.72 ± 1.54 h in Group M, respectively) (p = .001; p < .05). In Group D, the success rate of FTE was 92.5% (n = 123) and UFTE was 7.5% (n = 10) (p = .001). In Group M, the success rate of FTE was 72.9% (n = 86) and UFTE was 0% (n = 0) (p > .05).

CONCLUSIONS

Dexmedetomidine and morphine have clinical benefits which encourage their use for FTE protocol. Dexmedetomidine has more benefits compared to morphine. It can be used in UFTE protocol, besides its use in FTE protocol with fewer side effects.

Applications of Dexmedetomidine in Palliative and Hospice Care

Although the use of dexmedetomidine is currently approved by the US Food and Drug Administration in the adult population for monitored anesthesia care and sedation during mechanical ventilation, clinical experience suggests the potential application of dexmedetomidine in the palliative care arena. The medication can provide sedation with lower risk of delirium, control or minimize the adverse effects of other medications, and augment analgesia from opioids. We conducted a computerized bibliographic search of the literature regarding dexmedetomidine use for the treatment of pain and provision of sedation during palliative and hospice care in adult and pediatric patients. The objective was to provide a general descriptive account of the physiologic effects of dexmedetomidine and review its potential applications in the field of palliative and hospice care in adult and pediatric patients. The sedative and analgesic effects of dexmedetomidine have been well studied in animal and human models. Published experience from both single case reports and small case series has demonstrated the potential therapeutic applications of dexmedetomidine in palliative and hospice care. In addition to intravenous administration, case reports have demonstrated its successful use by both the intranasal and subcutaneous routes. Although these experiences have suggested its safety and efficacy, larger series and additional clinical experience with prospective comparison to other agents are needed to further define its efficacy and role in palliative and hospice care.

Weaning Dexmedetomidine in Non-ICU Areas: An Implementation Effort

OBJECTIVES

To develop and implement clinical practice guidelines for safely weaning dexmedetomidine infusions in non-ICU areas.

DESIGN

Development, implementation, and analysis of effectiveness of clinical practice guidelines.

SETTING

Quaternary care academic free-standing pediatric hospital.

PATIENTS

Children, otherwise medically ready for transfer to non-ICU areas, who were undergoing a planned wean of a dexmedetomidine infusion.

INTERVENTIONS

Subject matter experts developed evidence-based guidelines for weaning dexmedetomidine in patients whose critical phase of illness had resolved.

MEASUREMENTS AND MAIN RESULTS

Searches identified no prospective studies of dexmedetomidine weaning. We identified two retrospective reviews of withdrawal symptoms and one on the use of clonidine. There were case studies on withdrawal symptoms. Guidelines were piloted on a cohort of 24 patients while in the ICU. The guidelines were then implemented in non-ICU areas for patients undergoing dexmedetomidine weaning after ICU transfer. Over a 2-year period (October 1, 2018, to September 30, 2020), 63 patients (1 mo to 18 yr old) successfully weaned dexmedetomidine in non-ICU areas. The median time to discontinuation of dexmedetomidine after transfer to non-ICU areas was 5.8 days (interquartile range, 4.75-15 d). Fifty-eight percent (n = 41) of all patients were considered high risk for dexmedetomidine withdrawal based on the dose, duration of exposure, and the risk of experiencing physiologic detriment with more than mild withdrawal. Twenty-nine patients (46%) exhibited no signs or symptoms of withdrawal while weaning per guidelines. For those with signs and symptoms of withdrawal, the most common were tachycardia (n = 26, 40%), agitation (n = 9, 14%), and hypertension (n = 9, 11%).

CONCLUSIONS

Weaning dexmedetomidine in non-ICU areas is feasible and can be accomplished safely even among pediatric patients at high risk for withdrawal using standardized weaning guidelines. At our institution, implementation was associated with reduced ICU length of stay for patients recovering from critical illness.

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

BACKGROUND AND AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

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

Delirium in the NICU: Risk or Reality?

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

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

OBJECTIVE

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

METHOD

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

RESULTS

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

CONCLUSION

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

Clinical Practice: Should we Radically Alter our Sedation of Critical Care Patients, Especially Given the COVID-19 Pandemics?

The high number of patients infected with the SARS-CoV-2 virus requiring care for ARDS puts sedation in the critical care unit (CCU) to the edge. Depth of sedation has evolved over the last 40 years (no-sedation, deep sedation, daily emergence, minimal sedation, etc.). Most guidelines now recommend determining the depth of sedation and minimizing the use of benzodiazepines and opioids. The broader use of alpha-2 adrenergic agonists ('alpha-2 agonists') led to sedation regimens beginning at admission to the CCU that contrast with hypnotics+opioids ("conventional" sedation), with major consequences for cognition, ventilation and circulatory performance. The same doses of alpha-2 agonists used for 'cooperative' sedation (ataraxia, analgognosia) elicit no respiratory depression but modify the autonomic nervous system (cardiac parasympathetic activation, attenuation of excessive cardiac and vasomotor sympathetic activity). Alpha-2 agonists should be selected only in patients who benefit from their effects ('personalized' indications, as opposed to a 'one size fits all' approach). Then, titration to effect is required, especially in the setting of systemic hypotension and/or hypovolemia. Since no general guidelines exist for the use of alpha-2 agonists for CCU sedation, our clinical experience is summarized for the benefit of physicians in clinical situations in which a recommendation might never exist (refractory delirium tremens; unstable, hypovolemic, hypotensive patients, etc.). Because the physiology of alpha-2 receptors and the pharmacology of alpha-2 agonists lead to personalized indications, some details are offered. Since interactions between conventional sedatives and alpha-2 agonists have received little attention, these interactions are addressed. Within the existing guidelines for CCU sedation, this article could facilitate the use of alpha-2 agonists as effective and safe sedation while awaiting large, multicentre trials and more evidence-based medicine.

Dexmedetomidine versus midazolam on cough and recovery quality after partial and total laryngectomy - a randomized controlled trial

Background

During emergence from anesthesia after partial and total laryngectomy, excessive airway reflex and systemic hypertension may lead to subcutaneous emphysema, hemorrhage or pneumothorax.

Methods

American Society of Anesthesiologist physical status III and IV male adults undergoing elective laryngectomy were recruited and randomly allocated to receive either dexmedetomidine (group D) or midazolam (group M). The primary outcome was incidence and severity of cough. Pulse oximetry results (SpO₂), heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were also recorded. The visual analog scale and the Ramsay sedation scale were recorded at the points of wakefulness and departure from the post-anesthesia care unit (PACU). Rescue analgesia consumption, the time of spontaneous breath recovery, duration of the PACU stay, and the incidence of adverse effects were also recorded.

Results

The prevalence of no coughing was significantly higher in group D than in group M at the points of wakefulness and departure. HR, SBP, and DBP were significantly lower in group D compared with group M, and SpO₂ was significantly higher in group D than in group M at the moment of laryngectomy. Pain scores were lower in group D than in group M. The Ramsay score at the point of wakefulness was higher in group D than in group M. There was no difference in time to spontaneous breathing recovery, duration of the PACU stay, and incidence of adverse effects.

Conclusions

Compared with midazolam, dexmedetomidine is an effective alternative to attenuate coughing and hemodynamic changes with a low incidence of adverse events during emergence from anesthesia after partial and total laryngectomy.

Trial registration

NCT03918889, registered at clinicaltrials.gov, date of registration: March 28, 2019.

Emergence Agitation and Delirium: Considerations for Epidemiology and Routine Monitoring in Pediatric Patients

Emergence from anesthesia can be associated with a wide spectrum of cognitive and behavioral dysregulation in children, including delirium or acute brain dysfunction. This period of neurobehavioral recovery can be further confounded by pain, anxiety, and fear. The implementation of monitoring for level of consciousness, pain, and delirium using valid pediatric tools is necessary to avoid misdiagnosis due to overlapping symptomatology and support appropriate management. Understanding the epidemiology of delirium in the postoperative setting will require consistent use of accurate terminology in the medical literature. The current interchangeable use of the terms “emergence agitation” and “emergence delirium” needs to be highlighted and awareness of differences in patient conditions and assessment tools is essential. We discuss epidemiology of emergence agitation and delirium in the pediatric population, and the challenges for future delineation of monitoring and management. Furthermore, we describe the possible impact of long-term consequences of emergence delirium among infants and children, and the necessary areas of future research.

The effect of dexmedetomidine on motor-evoked potentials during pediatric posterior spinal fusion surgery: a retrospective case-control study

PURPOSE

Motor-evoked potentials (MEPs) are frequently used in pediatric posterior spinal fusion surgery (PSFS) to detect spinal cord ischemia. Dexmedetomidine is increasingly being used as an adjunct to total intravenous anesthesia, but its effect on MEP amplitude has been variably reported. The purpose of this study was to evaluate the effect of an infusion of dexmedetomidine on the amplitude of MEPs.

METHODS

We performed a retrospective case-control study of 30 pediatric patients who received a 0.5 µg·kg^-1·hr^-1 infusion of dexmedetomidine, ten patients who received 0.3 µg·kg^-1·hr^-1 dexmedetomidine, and 30 control patients who did not receive dexmedetomidine during PSFS. Two neurophysiologists reviewed the MEP amplitudes in six muscle groups at three time points: when the patient was turned prone (baseline; T1), one hour after incision (T2), and after exposure of the spine but before insertion of the first screw (T3).

RESULTS

In all muscles tested, the mean MEP amplitude was reduced by T3 when dexmedetomidine was infused at 0.5 µg·kg^-1·hr^-1. The greatest reduction from baseline MEP amplitude was 829 µV (95% confidence interval, 352 to 1230; P < 0.001) seen in first right dorsus interosseous. When dexmedetomidine was infused at 0.3 µg·kg^-1·hr^-1, there was a significant reduction in MEP amplitude in four of the six muscles tested at T3 compared with the control group.

CONCLUSIONS

Dexmedetomidine at commonly used infusion rates of 0.3 µg·kg^-1·hr^-1 or 0.5 µg·kg^-1·hr^-1 causes a significant decrease in MEP amplitude during pediatric PSFS. We suggest that dexmedetomidine should be avoided in children undergoing PSFS so as not to confuse the interpretation of this important neurophysiological monitor.

Perioperative Analgesia in Pediatric Patients Undergoing Otolaryngologic Surgery

This article reviews the evidence regarding current perioperative pain management strategies in pediatric patients undergoing otolaryngologic surgery. Pediatric otolaryngology is a broad field with a wide variety of surgical procedures that each requires careful consideration for optimal perioperative pain management. Adequate pain control is vital to ensuring patient safety and achieving successful postoperative care, but many young children are limited in their capacity to communicate their pain experience. Current literature holds a disproportionate amount of focus on pain management for certain procedures, whereas there is a paucity of evidence-based literature informing most other procedures within the field.

Value of Adding Dexmedetomidine in Endoscopic Ultrasound-Guided Celiac Plexus Neurolysis for Treatment of Pancreatic Cancer-Associated Pain

BACKGROUND

Abdominal and back pain is present in up to 80% of patients with pancreatic cancer and represents a significant cause of morbidity. Celiac plexus neurolysis (CPN) demonstrated good results in relief of pain of upper abdominal malignancy. Dexmedetomidine is alpha-2 adrenoceptor highly selective agonist approved for procedural sedation use.

PATIENTS AND METHODS

Fifty patients divided in two groups with locally advanced pancreatic cancer-associated abdominal pain underwent endoscopic ultrasound (EUS)-guided CPN using bupivacaine 0.5% alone with alcohol for the first group and bupivacaine 0.5% plus dexmedetomidine in the second. Patients scored their pain according to the Numeric Rating Scale (NRS-11) before, 2, 4, 6, 8, 12, 16, and 24 week after the procedure.

RESULTS

The study has included 50 patient in two groups. There was no significant difference between the two groups as regards medical, laboratory, or tumor characters. The median pain score decreases from 8.32 ± 0.75 before the procedure to 3.75 ± 3.72 24 week after the procedure in group 1 and from 8.08 ± 0.86 before to 1.67 ± 2.3 24 week after the procedure in group 2. However, there was no significant difference between the two groups in the median pain score during the first 4 weeks. There was no statistically significant difference between the two groups as regards the median survival time.

CONCLUSION

The addition of dexmedetomidine to bupivacaine 0.5% in EUS-CPN demonstrated beneficial effects as regards the degree and duration of pain relieve with negligible effect on the patient survival.

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

OBJECTIVES

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

DATA SOURCES

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

STUDY SELECTION

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

DATA EXTRACTION

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

DATA SYNTHESIS

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

CONCLUSIONS

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

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.

The Impact of a Clonidine Transition Protocol on Dexmedetomidine Withdrawal in Critically Ill Pediatric Patients

OBJECTIVES

This study describes our experience with a clonidine transition protocol to prevent dexmedetomidine (DEX) withdrawal in critically ill pediatric patients.

METHODS

Retrospective review of electronic medical records of patients in the pediatric intensive care unit of a single tertiary children's hospital. All patients up to 19 years of age, who received concomitant DEX infusion and enteral clonidine between June 1, 2016, and May 31, 2018, were included.

RESULTS

Two of 24 encounters had DEX restarted for withdrawal (8.3%). Five of 14 encounters who were transitioned to clonidine 2 mcg/kg every 6 hours required an increased dose, and 1 of 10 encounters transitioned to clonidine 4 mcg/kg every 6 hours required an increased dose (36% vs 10%, p = 0.21). For encounters with clonidine dose increases, 5 of 6 had improvements in Withdrawal Assessment Tool-1 (WAT-1) scores. Of these 5 encounters, 4 had decreasing or stable opioid and sedative requirements and 1 was transitioned to methadone. No encounters required discontinuation of clonidine owing to adverse events. Two of 24 encounters met our safety endpoint. One received a fluid bolus during the clonidine transition with no change in clonidine dosing, while the other had clonidine dose decreased for asymptomatic bradycardia.

CONCLUSIONS

The 24 encounters in our retrospective study add to the limited literature available to describe dosing, initiation time, and duration of clonidine to prevent withdrawal from DEX in critically ill pediatric patients. Further research is needed to clarify the optimal dosing and duration of clonidine to prevent DEX withdrawal in pediatric patients.

Dexmedetomidine extraction by the extracorporeal membrane oxygenation circuit: results from an in vitro study

BACKGROUND

Dexmedetomidine is a sedative administered to minimize distress and decrease the risk of life threatening complications in children supported with extracorporeal membrane oxygenation. The extracorporeal membrane oxygenation circuit can extract drug and decrease drug exposure, placing the patient at risk of therapeutic failure.

OBJECTIVE

To determine the extraction of dexmedetomidine by the extracorporeal membrane oxygenation circuit.

MATERIALS AND METHODS

Dexmedetomidine was studied in three closed-loop circuit configurations to isolate the impact of the oxygenator, hemofilter, and tubing on circuit extraction. Each circuit was primed with human blood according to standard practice for Duke Children's Hospital, and flow was set to 1 L/min. Dexmedetomidine was dosed to achieve a therapeutic concentration of ~600 pg/mL. Dexmedetomidine was added to a separate tube of blood to serve as a control and evaluate for natural drug degradation. Serial blood samples were collected over 24 hours and concentrations were quantified with a validated assay. Drug recovery was calculated at each time point.

RESULTS

Dexmedetomidine was highly extracted by the oxygenator evidenced by a mean recovery of 62-67% at 4 hours and 23-34% at 24 hours in circuits with an oxygenator in-line. In contrast, mean recovery with the oxygenator removed was 96% at 4 hours and 93% at 24 hours. Dexmedetomidine was stable over time with a mean recovery in the control samples of 102% at 24 hours.

CONCLUSION

These results suggest dexmedetomidine is extracted by the oxygenator in the extracorporeal membrane oxygenation circuit which may result in decreased drug exposure in vivo.

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.

Effects of Dexmedetomidine on Myocardial Repolarization in Children Undergoing General Anesthesia: A Randomized Controlled Trial

BACKGROUND

Dexmedetomidine is a highly selective α2-adrenergic agonist, which is increasingly used in pediatric anesthesia and intensive care. Potential adverse effects that have not been rigorously evaluated in children include its effects on myocardial repolarization, which is important given that the drug is listed as a possible risk factor for torsades de pointes. We investigated the effect of 3 different doses of dexmedetomidine on myocardial repolarization and transmural dispersion in children undergoing elective surgery with total IV anesthesia.

METHODS

Sixty-four American Society of Anesthesiologists I-II children 3-10 years of age were randomized to receive dexmedetomidine 0.25 µg/kg, 0.5 µg/kg, 0.75 µg/kg, or 0 µg/kg (control), as a bolus administered over 60 seconds, after induction of anesthesia. Pre- and postintervention 12-lead electrocardiograms were recorded. The interval between the peak and the end of the electrocardiogram T wave (Tp-e; transmural dispersion) and heart rate-corrected QT intervals (myocardial repolarization) were measured by a pediatric electrophysiologist blinded to group allocation. Data were analyzed using an analysis of covariance regression model. The study was powered to detect a 25-millisecond difference in Tp-e.

RESULTS

Forty-eight children completed the study, with data analyzed from 12 participants per group. There were no instances of dysrhythmias. Tp-e values were unaffected by dexmedetomidine administration at any of the studied doses (F = 0.09; P = .96). Mean (99% CI) within-group differences were all <2 milliseconds (-5 to 8). Postintervention, corrected QT interval increased in the control group, but decreased in some dexmedetomidine groups (F = 7.23; P < .001), specifically the dexmedetomidine 0.5 and 0.75 µg/kg doses. Within groups, the mean (99% CI) differences between pre- and postintervention corrected QT interval were 12.4 milliseconds (-5.8 to 30.6) in the control group, -9.0 milliseconds (-24.9 to 6.9) for dexmedetomidine 0.25 µg/kg, -18.6 milliseconds (-33.7 to -3.5) for dexmedetomidine 0.5 µg/kg, and -14.1 milliseconds (-27.4 to -0.8) for dexmedetomidine 0.75 µg/kg.

CONCLUSIONS

Of the bolus doses of dexmedetomidine studied, none had an effect on Tp-e and the dexmedetomidine 0.5 and 0.75 µg/kg doses shortened corrected QT intervals when measured at 1 minute after dexmedetomidine bolus injection during total IV anesthesia. There is no evidence for an increased risk of torsades de pointes in this context.

Effects of Dexmedetomidine on Blood Glucose and Serum Potassium Levels in Children Undergoing General Anesthesia: A Secondary Analysis of Safety Endpoints During a Randomized Controlled Trial

BACKGROUND

Dexmedetomidine is a highly selective α2-adrenergic agonist, which is increasingly used in pediatric anesthesia and intensive care. Potential adverse effects that have not been rigorously evaluated in children include its effects on blood glucose and serum potassium concentrations, which are relevant due to the associations of derangements of both parameters with undesired outcomes. We investigated the effects of 3 different doses of dexmedetomidine on these outcomes in a randomized controlled trial in children undergoing elective surgery.

METHODS

Sixty-four American Society of Anesthesiologists I-II children were randomized to receive either dexmedetomidine 0.25 µg/kg, dexmedetomidine 0.5 µg/kg, dexmedetomidine 0.75 µg/kg, or 0 µg/kg (control), as a bolus administered over 60 seconds after induction of anesthesia. Changes in plasma glucose and serum potassium concentrations were measured in venous blood sampled before and at 15 and 30 minutes after study drug administration. Data were plotted within and between groups and analyzed using a constrained longitudinal data approach.

RESULTS

Forty-nine children completed the study. Mean glucose levels at 15 and 30 minutes were elevated with estimated changes from baseline of 0.37 mmol/L (95% CI, 0.29-0.45 mmol/L) and 0.05 mmol/L (95% CI, 0.00-0.10 mmol/L), respectively. At 15 minutes, there was a linear dose-response relationship (1.07 mmol/L/μg/kg [95% CI, 0.57-1.58 mmol/L/μg/kg]), but there was no appreciable effect of dexmedetomidine at 30 minutes (0.15 mmol/L/μg/kg [95% CI, -0.40 to 0.70 mmol/L/μg/kg]). Potassium levels were depressed relative to baseline, with a mean difference at 15 minutes of -0.20 mEq/L (95% CI, -0.28 to -0.12 mEq/L) and at 30 minutes of -0.12 mEq/L (95% CI, -0.15 to -0.08 mEq/L), but there was no appreciable effect of dexmedetomidine at either time.

CONCLUSIONS

Small elevations in glucose and decreases in potassium were observed after induction of anesthesia in children. The elevation in glucose at 15 minutes depended on the dose of dexmedetomidine administered. These preliminary data warrant further investigation.

Postoperative nausea and vomiting after bariatric surgery and dexmedetomidine anesthetic: a propensity-weighted analysis

BACKGROUND

Patients undergoing laparoscopic bariatric surgery have high rates of postoperative nausea and vomiting (PONV). Dexmedetomidine based anesthetic could reduce PONV rates.

OBJECTIVES

To determine if PONV rates differ in patients undergoing laparoscopic bariatric surgery with anesthesia primarily based on dexmedetomidine or standard anesthetic management with inhalational agents and opioids.

SETTING

University hospital.

METHODS

From January 2014 to April 2018, 487 patients underwent laparoscopic bariatric surgery and met inclusion criteria (dexmedetomidine, n = 174 and standard anesthetic, n = 313 patients). In both groups, patients received preoperative PONV prophylaxis. We analyzed rates of PONV and moderate-to-deep sedation. A propensity score was calculated and outcomes were assessed using generalized estimating equations with inverse probability of treatment weighting.

RESULTS

Perioperative opioids and volatile anesthetics were reduced in dexmedetomidine patients. During anesthesia recovery the incidence of PONV was similar between dexmedetomidine and standard anesthetic patients (n = 37 [21.3%] versus n = 61 [19.5%], respectively; inverse probability of treatment weighting odds ratio = 1.35; 95% confidence interval .78-2.32, P = .281), and the incidence of sedation higher in dexmedetomidine patients (n = 86 [49.4%] versus n = 75 [24.0%]; inverse probability of treatment weighting odds ratio = 2.43; 95% confidence interval 1.47-4.03, P < 0.001). Rates of PONV and sedation were similar during the remainder of the hospital stay. A secondary sensitivity analysis was performed limited to dexmedetomidine patients who did not receive volatile and results were similar.

CONCLUSIONS

While dexmedetomidine-based anesthesia was associated with reduced opioid and volatile agents use, it was not associated with a reduction of PONV. The higher rates of moderate-to-deep sedation during anesthesia recovery observed with dexmedetomidine may be undesirable in morbidly obese patients.

Sedative and Analgesic Drug Rotation Protocol in Critically Ill Children With Prolonged Sedation: Evaluation of Implementation and Efficacy to Reduce Withdrawal Syndrome

OBJECTIVES

The first aim of this study was to assess the implementation of a sedative and analgesic drug rotation protocol in a PICU. The second aim was to analyze the incidence of withdrawal syndrome, drug doses, and time of sedative or analgesic drug infusion in children after the implementation of the new protocol.

DESIGN

Prospective observational study.

SETTING

PICU of a tertiary care hospital between June 2012 and June 2016.

PATIENTS

All patients between 1 month and 16 years old admitted to the PICU who received continuous IV infusion of sedative or analgesic drugs for more than 4 days were included in the study.

INTERVENTIONS

A sedative and analgesic drug rotation protocol was designed. The level of sedation, analgesia, and withdrawal syndrome were monitored with validated scales. The relationship between compliance with the protocol and the incidence of withdrawal syndrome was studied.

MEASUREMENTS AND MAIN RESULTS

One-hundred pediatric patients were included in the study. The protocol was followed properly in 35% of patients. Sixty-seven percent of the overall cohort presented with withdrawal syndrome. There was a lower incidence rate of withdrawal syndrome (34.3% vs 84.6%; p < 0.001), shorter PICU length of stay (median 16 vs 25 d; p = 0.003), less time of opioid infusion (median 5 vs 7 d for fentanyl; p = 0.004), benzodiazepines (median 5 vs 9 d; p = 0.001), and propofol (median 4 vs 8 d; p = 0.001) in the cohort of children in which the protocol was followed correctly.

CONCLUSIONS

Our results show that compliance with the drug rotation protocol in critically ill children requiring prolonged sedation may reduce the appearance of withdrawal syndrome without increasing the risk of adverse effects. Furthermore, it may reduce the time of continuous IV infusions for most sedative and analgesic drugs and the length of stay in PICU.

Hypothermia Following Spinal Anesthesia in an Infant: Potential Impact of Intravenous Dexmedetomidine and Intrathecal Clonidine

The α₂-adrenergic agonists (dexmedetomidine and clonidine) have been used in several different clinical scenarios in infants and children including sedation during mechanical ventilation, procedural sedation, supplementation of postoperative analgesia, prevention of emergence delirium, control of post-anesthesia shivering, treatment of withdrawal and prolonging of duration of neuraxial anesthesia. Hemodynamic effects including bradycardia and hypotension remain the predominant adverse effects reported with the α₂-adrenergic agonists. We report hypothermia following intravenous sedation with dexmedetomidine and spinal anesthesia with a combination of bupivacaine and clonidine in a 2-month-old infant. The potential mechanisms involved are reviewed, the causal relationship between hypothermia and α₂-adrenergic agonists is explored and interventions to avoid its development are presented.

Sedation strategies in children with pediatric acute respiratory distress syndrome (PARDS)

In this review, we discuss the changing landscape of sedation in mechanically ventilated children with pediatric acute respiratory distress syndrome (PARDS). While previous approaches advocated for early and deep sedation with benzodiazepines, emerging literature has highlighted the benefits of light sedation and use of non-benzodiazepine sedating agents, such as dexmedetomidine. Recent studies have emphasized the importance of monitoring multiple factors including, but not limited to, sedation depth, analgesia efficacy, opiate withdrawal, and development of delirium. Through this approach, we hope to improve PARDS outcomes. Overall, more research is needed to further our understanding of the best sedation strategies in children with PARDS.

Use of dexmedetomidine in pediatric cardiac anesthesia

PURPOSE OF REVIEW

In recent years, ultrafast-track anesthesia with on-table extubation and concepts of accelerated postoperative care have gained increasing support in pediatric congenital cardiac surgery. It is believed that such approaches might ideally combine economic benefits with a striving for continuous improvement of patient outcomes. The present review summarizes the role of dexmedetomidine (DEX) in this setting.

RECENT FINDINGS

DEX is a clinical multipurpose drug that mediates its diverse responses through the activation of α2-adrenoreceptors. In pediatric cardiac surgery it has various applications. Used as a premedication, DEX provides arousable sedation and anxiolysis. As an intraoperative adjunctive agent of balanced general anesthesia the primary objectives for its administration are attenuation of the neuro-humoral stress response and facilitation of early extubation. During ICU treatment DEX spares opioids, prevents the risk of postoperative delirium or emergence agitation and impacts on important patient-centered outcomes, such as duration of mechanical ventilation, restart of enteral nutrition or length of ICU stay.

SUMMARY

Due to a favorable mix of beneficial physiologic actions and a limited adverse effect profile, DEX is established in the perioperative pediatric cardiac surgery setting. However, evidence from high-quality randomized controlled trials on the effects of supplemental DEX on meaningful patient outcomes is scarce, and research on the role of DEX in providing cardioprotection, neuroprotection, or renoprotection is still at its beginning. DEX has developed to one of the main agents in the armamentarium of cardiac anesthesiologists and pediatric intensivists, but it should not be regarded as the new 'magic bullet'.

Safety and Efficacy of Buccal Dexmedetomidine for MRI Sedation in School-Aged Children

OBJECTIVES

Intranasal, intramuscular, and intravenous (IV) dexmedetomidine routes have been used successfully for pediatric MRI studies. We designed this retrospective study to determine efficacy and safety of buccal dexmedetomidine for pediatric MRI sedation.

METHODS

Medical records were reviewed of outpatient children ages 5 to 18 years who received buccal dexmedetomidine with or without oral midazolam for MRI sedation at a freestanding children's hospital sedation program in 2015 and 2016.

RESULTS

A total of 220 outpatient encounters received buccal dexmedetomidine for MRI. Mean age of the cohort was 10.1 ± 2.6 years (range: 5-18.7). Buccal dexmedetomidine dose administered was a mean of 2.20 ± 0.38 μg/kg (range: 0.88-3.19). Of the 220 sedation encounters, 179 (81.4%) patients had satisfactory sedation with buccal dexmedetomidine with or without oral midazolam: 84 had buccal dexmedetomidine as the sole sedative, 95 had satisfactory sedation when buccal dexmedetomidine and oral midazolam (mean: 0.33 ± 0.07 mg/kg; range: 0.21-0.53) were given together, 1 (0.4%) had satisfactory sedation when intranasal fentanyl and midazolam were administered in addition to buccal dexmedetomidine, and 35 (15.9%) required IV sedatives to achieve satisfactory sedation. All patients completed their MRI successfully except 5 (2.2%): 2 encounters were sedation failures, 2 IV sedations developed severe upper airway obstruction, and 1 IV sedation experienced MRI contrast anaphylaxis.

CONCLUSIONS

In a selected population of pediatric patients, buccal dexmedetomidine with or without midazolam provides adequate sedation for most MRI studies with few adverse effects, but given a failure rate of almost 20%, modifications to buccal dexmedetomidine dosing should be investigated.

Survey of the Current Use of Dexmedetomidine and Management of Withdrawal Symptoms in Critically Ill Children

OBJECTIVES

Dexmedetomidine use for sedation in the pediatric intensive care units (PICUs) has increased since its initial US Food and Drug Administration (FDA) approval in adults. However, there is limited evidence to direct providers regarding current usage, dosing, and monitoring for withdrawal symptoms in pediatric patients. This study sought to determine the utilization of dexmedetomidine and management of dexmedetomidine withdrawal symptoms among PICU physicians.

METHODS

A questionnaire survey was distributed to all members of the American Academy of Pediatrics Section on Critical Care. It assessed the practice site demographics, indication, dosing, and duration of dexmedetomidine infusion, unit protocol, and strategies for management of dexmedetomidine withdrawal.

RESULTS

A total of 147 surveys (21.1%) were returned and analyzed. The reported uses for dexmedetomidine were as a primary sedative (59.9%), adjunctive agent for sedation (82.3%), and adjunctive agent to assist weaning sedation (62.6%) or from mechanical ventilation (70.1%). One hundred twenty-nine respondents (87.8%) had concerns over dexmedetomidine withdrawal, with 59 respondents becoming concerned after 120 hours of infusion (45.7%). Most respondents reported managing dexmedetomidine withdrawal symptoms via a regimented wean and initiation of clonidine (81%). Units with >1000 admissions per year were more likely to have a protocol related to dexmedetomidine use (p = 0.021). Units with >1000 admissions per year reported using clonidine for withdrawal at a higher rate, whereas units with ≤1000 admissions per year used a systematic wean of dexmedetomidine (p = 0.014).

CONCLUSIONS

Dexmedetomidine use in the PICU is varied among pediatric intensive care physicians. Intensivists have withdrawal concerns after dexmedetomidine discontinuation, and the primary management of this withdrawal phenomenon is the initiation of clonidine with a regimented dexmedetomidine wean.

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.

General Anesthesia With Dexmedetomidine and Remifentanil in a Neonate During Oracotomy and Resection of a Congenital Cystic Adenomatoid Malformation

Based on animal data, concern has been expressed regarding the potential deleterious neurocognitive effects of general anesthesia during infancy and early life. Although there are no definitive data to prove this effect, the neonatal period has been suggested to be the most vulnerable period. While various inhaled and intravenous anesthetic agents have been implicated, dexmedetomidine and the opioids may be devoid of such effects. However, there are limited data regarding the combination of these agents during neonatal surgery and anesthesia. We present the use of these agents in combination with epidural anesthesia for postoperative analgesia in a 1-day-old neonate during thoracotomy and excision of a congental cystic adenomatoid malformation. Previous reports of the use of this unique combination of agents are reviewed and their role in this scenario discussed.

Dexmedetomidine as Single Continuous Sedative During Noninvasive Ventilation: Typical Usage, Hemodynamic Effects, and Withdrawal

OBJECTIVES

Dexmedetomidine use in pediatric critical care is increasing. Its prolonged effects as a single continuous agent for sedation are not well described. The aim of the current study was to describe prolonged dexmedetomidine therapy without other continuous sedation, specifically the hemodynamic effects, discontinuation strategies, and risk factors for withdrawal.

DESIGN

Retrospective chart review.

SETTING

Large, single-center, quaternary care pediatric academic institution.

PATIENTS

Data from 382 children, less than 18 years old admitted to the PICU who received dexmedetomidine for more than 24 hours without other infusions for sedation during noninvasive positive pressure ventilation.

INTERVENTIONS

Usual care practices for dexmedetomidine use were described. Discontinuation strategies were categorized as abrupt discontinuation, wean from dexmedetomidine infusion, and transition to enteral clonidine.

MEASUREMENTS AND MAIN RESULTS

Median peak and cumulative doses with interquartile range were 1 µg/kg/hr (0.6-1.2 µg/kg/hr) and 30 µg/kg (20-50 µg/kg), respectively, and median duration was 45 hours (34-66 hr). Four hours after reaching peak dose, we observed a decrease in heart rate (p < 0.01) with 28% prevalence of bradycardia and an increase in systolic blood pressure (p < 0.01) with 33% prevalence of hypertension and 2% hypotension. During the escalation phase, the prevalence of bradycardia and hypotension were 75% and a 30%, respectively. Three-hundred thirty-six patients (88%) had abrupt discontinuation, 37 (10%) were weaned, and nine (2%) were transitioned to clonidine. Nineteen patients (5%) experienced withdrawal. Univariate risk of withdrawal was most associated with duration: odds ratio equal to 1.5 (1.3-1.7) for each 12-hour period (p < 0.01). By multivariate analysis including age, discontinuation group, dexmedetomidine cumulative dose, and peak dose, only cumulative dose remained significant with an odds ratio equal to 1.3 (1.1-1.5) for each 10 μg/kg (p < 0.01).

CONCLUSIONS

Dexmedetomidine use for noninvasive positive pressure ventilation sedation in pediatric critical care has predictable hemodynamic effects including bradycardia and hypertension. Although withdrawal was associated with higher cumulative dose, these symptoms were effectively managed with short-term enteral clonidine.

Postoperative bradycardia following adenotonsillectomy in children: Does intraoperative administration of dexmedetomidine play a role?

INTRODUCTION

Dexmedetomidine is a novel pharmacologic agent that has become a frequently used adjunct during care of pediatric patients with obstructive sleep apnea (OSA) undergoing tonsillectomy. While generally safe and effective, dexmedetomidine is associated with adverse effects of hypotension and bradycardia from its central sympatholytic effects. Due to safety concerns, our institution routinely admits patients with OSA for overnight cardiorespiratory monitoring following tonsillectomy. With such monitoring, we have anecdotally noted bradycardia in our patients and sought to investigate whether this was related to the increased use of intra-operative dexmedetomidine.

METHODS

We retrospectively reviewed records over an 11-month period to compare the incidence of postoperative bradycardia following hospital admission for tonsillectomy in patients who received dexmedetomidine versus those who did not.

RESULTS

The study cohort included 921 patients (371 received dexmedetomidine and 550 did not). Bradycardia was asymptomatically noted in 66 patients (7.2%). No patient required medical intervention for the bradycardia or developed clinical symptoms. There was no association of bradycardia with the intra-operative administration of dexmedetomidine (8.9% of patients who received dexmetomidine vs. 9.4% who did not). In multivariable analysis, bradycardia was more common among older patients, with the administration of topical or injected lidocaine, and with specific associated procedures (inferior turbinate coblation with out-fracture or direct laryngoscopy and bronchoscopy).

CONCLUSION

The increased incidence of asymptomatic bradycardia in our post-adenotonsillectomy patients seemed to relate more to increased utilization of postoperative cardiac telemetry, and did not appear associated with the use of dexmedetomidine use intra-operatively.

A Combination of Dexmedetomidine and Lidocaine Is a Cardiovascularly Safe Dental Local Anesthetic for Hypertensive Rats Treated With a Nonselective β-Adrenergic Antagonist

Hypertensive patients receiving nonselective β-adrenergic antagonists are vulnerable to hypertension and bradycardia when injected with dental local anesthetic formulations containing epinephrine. Dexmedetomidine (DEX), an α₂-adrenergic agonist, has been reported to prolong and enhance the local anesthetic effects of lidocaine. The cardiovascular effects of the DEX-lidocaine combination have not yet been investigated in the presence of nonselective β-adrenergic antagonists. Therefore, we assessed the cardiovascular effects of the DEX-lidocaine combination in spontaneously hypertensive rats (SHR) treated with a nonselective β-adrenergic antagonist (propranolol). We injected propranolol-treated rats with various concentrations of DEX alone, 100 μg/kg epinephrine alone, or 5 μg/kg DEX combined with 2% lidocaine and measured their blood pressure (BP) and heart rates (HR) to assess the cardiovascular effects. The BP of propranolol-treated SHR was significantly increased by treatment with 100 μg/kg epinephrine alone. The BP and HR of propranolol-treated SHR were not significantly changed by treatment with low concentrations of DEX, but they were significantly decreased by treatment with a high concentration of DEX (50 μg/kg). Moreover, there was no significant difference in the BP and HR of propranolol-treated SHR after the injection of a combination of 5 μg/kg DEX and 2% lidocaine. Thus, the DEX-lidocaine combination may be an acceptable addition to dental local anesthetic solutions from a cardiovascular standpoint for hypertensive patients receiving nonselective β-adrenergic antagonists.