The use of dexmedetomidine to facilitate opioid and benzodiazepine detoxification in an infant

Analgesia, Sedation, and Anesthesia for Neonates With Cardiac Disease

Analgesia, sedation, and anesthesia are a continuum. Diagnostic and/or therapeutic procedures in newborns often require analgesia, sedation, and/or anesthesia. Newborns, in general, and, particularly, those with heart disease, have an increased risk of serious adverse events, including mortality under anesthesia. In this section, we discuss the assessment and management of pain and discomfort during interventions, review the doses and side effects of commonly used medications, and provide recommendations for their use in newborns with heart disease. For procedures requiring deeper levels of sedation and anesthesia, airway and hemodynamic support might be necessary. Although associations of long-term deleterious neurocognitive effects of anesthetic agents have received considerable attention in both scientific and lay press, causality is not established. Nonetheless, an early multimodal, multidisciplinary approach is beneficial for safe management before, during, and after interventional procedures and surgery to avoid problems of tolerance and delirium, which can contribute to long-term cognitive dysfunction.

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.

Dexmedetomidine to Treat 3, 4-Methylenedioxymethamphetamine-Induced Agitation in a 13-Month-Old Infant: A Case Report and Literature Review

We report a 13-month-old infant who accidentally ingested a tablet of 3, 4-methylenedioxymethamphetamine (MDMA) and was brought to the emergency department with tachycardia, seizures, mydriasis, and altered mental status. The patient received multiple doses of benzodiazepines to treat the seizures and developed respiratory insufficiency needing intubation. After extubation, the patient developed hyperactivity, myoclonic, and choreoathetoid movements which were unresponsive to benzodiazepines. Dexmedetomidine was started with good response. The patient made a full clinical recovery. This is the first case that illustrates the possibility to treat MDMA-induced agitation with dexmedetomidine in a 13-month-old infant.

Opioid tapering and weaning protocols in pediatric critical care units: a systematic review

OBJECTIVE

Opioid abstinence syndrome is common in the pediatric intensive care environment because sedation is often needed during the children's treatment. There is no specific guideline regarding the management of these patients; and lately, methadone is an important drug for the prevention of abstinence symptoms during the weaning of opioids. This study gathers the available research to establish the initial dose of methadone, the rate of taper and tools to recognize this syndrome and act promptly.

METHODS

A systematic review was made from data of four different databases. Forty-nine articles of observational and experimental studies were selected based on the inclusion criteria (critical pediatric patients in acute use of opioids) and exclusion criteria (previous chronic use of opioids, other medications). The data regarding specific themes were separated in sections: initial dose of methadone, use of protocols in clinical practice, abstinence scales and adjuvant drugs.

RESULTS

The articles showed a great heterogeneity of ways to calculate the initial dose of methadone. The pediatric intensive care units of the study had different weaning protocols, with a lower incidence of abstinence when a pre-defined sequence of tapering was used. The Withdrawal Assessment Tool - 1 was the most used scale for tapering the opioids, with good sensitivity and specificity for signs and symptoms.

CONCLUSION

There is still little evidence of other medications that can help prevent the abstinence syndrome of opioids. This study tries to promote a better practice during opioid weaning.

The Use of Dexmedetomidine in Pediatric Palliative Care: A Preliminary Study

OBJECTIVE

To evaluate the effect of dexmedetomidine infusions in patients with advanced malignancies, advanced heart disease, or after stem cell transplantation (SCT), who during end-of-life care had pain and/or agitation unresponsive to conventional therapies.

BACKGROUND

Pediatric patients with intractable advanced malignancies, end-stage congenital heart diseases, or after SCT can suffer a great deal during end of life. Pain, drowsiness, fatigue, irritability, and worrying are experienced frequently, considered distressing, and are strongly associated with reductions in health-related quality-of-life scores. While opioids are the mainstay of analgesic therapy, in some patients, increasing opioid use can be ineffective and can be associated with increasing pain during end of life. Dexmedetomidine, a α₂-adrenoreceptor agonist with sedative and analgesic properties but without respiratory depressant effects, has been shown to reduce opioid requirement and to facilitate opioid weaning.

METHODS

Observational cohort study of consecutive patients treated with dexmedetomidine during end of life in a pediatric hospital. Primary outcomes included pain scores and morphine-equivalent intake.

RESULTS

We identified nine patients [median age 8 (interquartile range; IQR 0.55-17 years)] who during end of life had received dexmedetomidine infusions. In these patients, dexmedetomidine infusions had a median duration of two days (IQR 1.5-12 days) and were associated with significant (p < 0.001) reductions in pain scores and a trend toward decreasing morphine-equivalent intake. There were no hemodynamic changes requiring vasoactive or anticholinergic agents.

CONCLUSIONS

These preliminary findings of beneficial effects of dexmedetomidine support the hypothesis that dexmedetomidine has a role in palliative care of children and adolescents during end of life.

Dexmedetomidine Use in Critically Ill Children With Acute Respiratory Failure

OBJECTIVE

Care of critically ill children includes sedation but current therapies are suboptimal. To describe dexmedetomidine use in children supported on mechanical ventilation for acute respiratory failure.

DESIGN

Secondary analysis of data from the Randomized Evaluation of Sedation Titration for Respiratory Failure clinical trial.

SETTING

Thirty-one PICUs.

PATIENTS

Data from 2,449 children; 2 weeks to 17 years old.

INTERVENTIONS

Sedation practices were unrestrained in the usual care arm. Patients were categorized as receiving dexmedetomidine as a primary sedative, secondary sedative, periextubation agent, or never prescribed. Dexmedetomidine exposure and sedation and clinical profiles are described.

MEASUREMENTS AND MAIN RESULTS

Of 1,224 usual care patients, 596 (49%) received dexmedetomidine. Dexmedetomidine as a primary sedative patients (n = 138; 11%) were less critically ill (Pediatric Risk of Mortality III-12 score median, 6 [interquartile range, 3-11]) and when compared with all other cohorts, experienced more episodic agitation. In the intervention group, time in sedation target improved from 28% to 50% within 1 day of initiating dexmedetomidine as a primary sedative. Dexmedetomidine as a secondary sedative usual care patients (n = 280; 23%) included more children with severe pediatric acute respiratory distress syndrome or organ failure. Dexmedetomidine as a secondary sedative patients experienced more inadequate pain (22% vs 11%) and sedation (31% vs 16%) events. Dexmedetomidine as a periextubation agent patients (n = 178; 15%) were those known to not tolerate an awake, intubated state and experienced a shorter ventilator weaning process (2.1 vs 2.3 d).

CONCLUSIONS

Our data support the use of dexmedetomidine as a primary agent in low criticality patients offering the benefit of rapid achievement of targeted sedation levels. Dexmedetomidine as a secondary agent does not appear to add benefit. The use of dexmedetomidine to facilitate extubation in children intolerant of an awake, intubated state may abbreviate ventilator weaning. These data support a broader armamentarium of pediatric critical care sedation.

Dexmedetomidine in the Treatment of Withdrawal Syndromes in Cardiothoracic Surgery Patients

Dexmedetomidine (Precedex, Abbott Laboratories, Abbott Park, IL) is an• 2adrenergic agonist that possesses a high ratio of specificity for the• 2versus the• 1receptor. It is currently approved for the provision of sedation during mechanical ventilation in adults. Given previous experience with clonidine for the treatment of substance withdrawal and the preliminary anecdotal experience with dexmedetomidine, it appears that dexmedetomidine may be a useful agent for treatment of substance withdrawal in the intensive care setting. The authors present their experience with the use of dexmedetomidine to control withdrawal behavior in 3 patients following cardiothoracic surgery. Previous reports regarding the use of dexmedetomidine to treat withdrawal and its potential application in this clinical arena are reviewed.

Nonmedical use of prescription drugs in the European Union

BACKGROUND

Nonmedical prescription drug use (NMPDU) refers to the self-treatment of a medical condition using medication without a prescriber's authorization as well as use to achieve euphoric states. This article reports data from a cross-national investigation of NMPDU in five European Countries, with the aim to understand the prevalence and characteristics of those engaging in NMPDU across the EU.

METHODS

A parallel series of self-administered, cross-sectional, general population surveys were conducted in 2014. Data were collected using multi-stage quota sampling and then weighted using General Exponential Model. A total of 22,070 non-institutionalized participants, aged 12 to 49 years, in 5 countries: Denmark, Germany, Great Britain, Spain, and Sweden. Lifetime and past-year nonmedical use of prescription medications such as stimulants, opioids, and sedatives were ascertained via a modified version of the World Health Organization's Composite International Diagnostic Interview. Information about how the medications were acquired for NMPDU were also collected from the respondent.

RESULTS

Lifetime and past-year prevalence of nonmedical prescription drug use was estimated for opioids (13.5 and 5.0 %), sedatives (10.9 and 5.8 %), and stimulants (7.0 and 2.8 %). Germany exhibited the lowest levels of NMPDU, with Great Britain, Spain, and Sweden having the highest levels. Mental and sexual health risk factors were associated with an increased likelihood of past-year nonmedical prescription drug use. Among past-year users, about 32, 28, and 52 % of opioid, sedative, and stimulant nonmedical users, respectively, also consumed illicit drugs. Social sources (sharing by friends/family) were the most commonly endorsed methods of acquisition, ranging from 44 % (opioids) to 62 % (sedatives). Of interest is that Internet pharmacies were a common source of medications for opioids (4.1 %), stimulants (7.6 %), and sedatives (2.7 %).

CONCLUSIONS

Nonmedical prescription drug use was reported across the five EU countries we studied, with opioids and sedatives being the most prevalent classes of prescription psychotherapeutics. International collaborations are needed for continued monitoring and intervention efforts to target population subgroups at greatest risk for NMDU.

Tolerance and Withdrawal Issues with Sedatives in the Intensive Care Unit

Prolonged use of sedative medications continues to be a concern for critical care practitioners, with potential adverse effects including tolerance and withdrawal. The amount of sedatives required in critically ill patients can be lessened and tolerance delayed with the use of pain and/or sedation scales to reach the desired effect. The current recommendation for prolonged sedation is to wean patients from the medications over several days to reduce the risk of drug withdrawal. It is important to identify patients at risk for iatrogenic withdrawal and create a treatment strategy.

Dexmedetomidine as an Adjuvant to Analgesic Strategy During Vaso-Occlusive Episodes in Adolescents with Sickle-Cell Disease

Patients with sickle-cell disease (SCD) can experience recurrent vaso-occlusive episodes (VOEs), which are associated with severe pain. While opioids are the mainstay of analgesic therapy, in some patients with SCD, increasing opioid use is associated with continued and increasing pain. Dexmedetomidine, an α2 -adrenoreceptor agonist with sedative and analgesic properties, has been increasingly used in the perioperative and intensive care settings and has been shown to reduce opioid requirement and to facilitate opioid weaning. Therefore, there might be a role for dexmedetomidine in pain management during VOEs in patients with SCD. Here, we present the hospital course of 3 patients who during the course of VOEs had severe pain unresponsive to opioids and ketamine and were treated with dexmedetomidine. Dexmedetomidine infusions that lasted for 3 to 6 days were associated with marked reduction in daily oral morphine-equivalent intake and decreases in pain scores (numeric rating scale). There were no hemodynamic changes that required treatment with vasoactive or anticholinergic agents. These preliminary findings of possible beneficial effects of dexmedetomidine in decreasing opioid requirements support the hypothesis that dexmedetomidine may have a role as a possible analgesic adjuvant to mitigate VOE-associated pain in patients with SCD.

Dexmedetomidine: a review of applications for cardiac surgery during perioperative period

Cardiac surgery is associated with a high incidence of cardiovascular and other complications during the perioperative period that translate into increased mortality and prolonged hospital stays. Safe comprehensive perioperative management is required to eliminate these adverse events. Dexmedetomidine is a selective α2-adrenoreceptor agonist that has been described as an ideal medication in the perioperative period of cardiac surgery. The major clinical effects of dexmedetomidine in this perioperative period can be summarized as attenuating the hemodynamic response, cardioprotective effects, antiarrhythmic effects, sedation in the ICU setting, treatment of delirium, and procedural sedation. Although there are some side effects of dexmedetomidine, it is emerging as an effective therapeutic agent in the management of a wide range of clinical conditions with an efficacious, safe profile. The present review serves as an overview update in the diverse applications of dexmedetomidine for cardiac surgery during the perioperative period.

Dexmedetomidine: a review of applications for cardiac surgery during perioperative period

Cardiac surgery is associated with a high incidence of cardiovascular and other complications during the perioperative period that translate into increased mortality and prolonged hospital stays. Safe comprehensive perioperative management is required to eliminate these adverse events. Dexmedetomidine is a selective α2-adrenoreceptor agonist that has been described as an ideal medication in the perioperative period of cardiac surgery. The major clinical effects of dexmedetomidine in this perioperative period can be summarized as attenuating the hemodynamic response, cardioprotective effects, antiarrhythmic effects, sedation in the ICU setting, treatment of delirium, and procedural sedation. Although there are some side effects of dexmedetomidine, it is emerging as an effective therapeutic agent in the management of a wide range of clinical conditions with an efficacious, safe profile. The present review serves as an overview update in the diverse applications of dexmedetomidine for cardiac surgery during the perioperative period.

Dexmedetomidine infusion to facilitate opioid detoxification and withdrawal in a patient with chronic opioid abuse

Many patients are admitted to the intensive care unit (ICU) for acute intoxication, serious complication of overdose, or withdrawal symptoms of illicit drugs. An acute withdrawal of drugs with addiction potential is associated with a sympathetic overactivity leading to marked psychomimetic disturbances. Acute intoxication or withdrawal of such drugs is often associated with life-threatening complications which require ICU admission and necessitate prolonged sedative analgesic medications, weaning from which is often complicated by withdrawal and other psychomimetic symptoms. Dexmedetomidine, an alpha-2 (α(2)) agonist, has been used successfully to facilitate withdrawal and detoxification of various drugs and also to control delirium in ICU patients. Herein, we report a case of a chronic opioid abuse (heroin) patient admitted with acute overdose complications leading to a prolonged ICU course requiring sedative-analgesic medication; the drug withdrawal-related symptoms further complicated the weaning process. Dexmedetomidine infusion was successfully used as a sedative-analgesic to control the withdrawal-related psychomimetic symptoms and to facilitate smooth detoxification and weaning from opioid and other sedatives.

Dexmedetomidine for opioid and benzodiazepine withdrawal in pediatric patients

PURPOSE

The published literature on the use of dexmedetomidine as an adjunct to sedation and analgesia in the management of pediatric narcotic withdrawal was reviewed.

SUMMARY

Pediatric narcotic withdrawal syndromes are reported to be increasingly frequent in pediatric intensive care units. A number of tools specifically designed for assessment of withdrawal in newborns and infants are in current use, including the widely used Finnegan Scoring System. A limited number of studies and case reports suggest that dexmedetomidine, an α(2)-receptor agonist with a mechanism of action similar to that of clonidine but with greater α(2)-receptor specificity, might have a role in the treatment of pediatric withdrawal (by blunting withdrawal symptoms without causing respiratory depression and by permitting shorter narcotic tapering schedules) and also in the prevention of pediatric narcotic withdrawal (by reducing narcotic requirements). Potential adverse effects associated with dexmedetomidine use in pediatric patients are generally associated with use of bolus doses and mainly involve central nervous system effects (e.g., hypotension, bradycardia), with no hemodynamic manifestations. When bolus doses are used, strategies described in published reports entail a loading dose of 0.5-1.0 μg/kg administered over 5-10 minutes, followed by a continuous infusion at 0.1-1.4 μg/kg/hr for a period of 1-16 days. More research is needed to define the optimal use of dexmedetomidine in the management of pediatric narcotic withdrawal.

CONCLUSION

A limited body of published evidence from retrospective studies and case reports suggests a potential role for dexmedetomidine as an adjunct therapy to provide sedation and analgesia to reduce narcotic withdrawal symptoms in pediatric patients.

Dexmedetomidine: applications for the pediatric patient with congenital heart disease

This study aimed to provide a general description of the cardiovascular and hemodynamic effects of dexmedetomidine and an evidence-based review of the literature regarding its use in infants and children with congenital heart disease (CHD). A computerized bibliographic search of the literature on dexmedetomidine use in infants and children with CHD was performed. The cardiovascular effects of dexmedetomidine have been well studied in animal and adult human models. Adverse cardiovascular effects include occasional episodes of bradycardia, with rare reports of sinus pause or cardiac arrest. Both hypotension and hypertension also have been reported. The latter is related to peripheral α(2B) agonism leading to vasoconstriction. No adverse effects on the pulmonary vasculature have been noted even in patients with preexisting pulmonary hypertension. Although there are no direct effects on myocardial function, decreased cardiac output may result from changes in heart rate or increases in afterload. Although not currently Food and Drug Administration (FDA)-approved for the pediatric population, findings have shown dexmedetomidine to be effective in various clinical scenarios of patients with CHD including sedation during mechanical ventilation, prevention of procedure-related anxiety, prevention of emergence delirium and shivering after anesthesia, and treatment of withdrawal. Although dexmedetomidine may have limited utility for painful or invasive procedures, preliminary data suggest that the addition of ketamine to the regimen may offer benefits. When used during the perioperative period, additional benefits include blunting of the sympathetic stress response with a reduction of endogenous catecholamine release, a decrease in intraoperative anesthetic requirements, and a limitation of postoperative opioid requirements.

Dexmedetomidine use in the setting of cocaine-induced hypertensive emergency and aortic dissection: a novel indication

Aortic dissection is a potentially fatal but rare disease characterized by an aortic intimal tear with blood passing into the media creating a false lumen and with resultant high mortality depending on the location of dissection if not aggressively treated. Cocaine users are known to have a higher incidence of aortic dissection. We report here aortic dissection in a patient with cocaine abuse which did not respond to traditional medication regimes used currently in this setting. Worth mentioning is the use of an alpha-2 receptor selective agonist named Dexmedetomidine as a treatment modality to control hypertension in this patient, which is approved only for sedation of intubated and mechanically ventilated patients in the intensive care settings and for sedation during invasive procedures. This paper illustrates the practical beneficial role of Dexmedetomidine in controling blood pressure in the settings of cocaine-induced sympathetic surge when other treatment modalities fail.

Review Article: Dexmedetomidine: Does it Have Potential in Palliative Medicine?

Dexmedetomidine, is a α 2 adrenergic agonist approved by the Food and Drug administration for sedation and analgesia. A highly potent α2 adrenergic agonist, it has quick onset of action, with peak effects within 1 hour of administration. It is metabolized in the liver and eliminated in the urine as a glucuronide. Dexmedetomidine is a substrate and inhibitor of cytochrome oxidase 2D6, but clinical evidence of significant drug interactions is lacking. Clinical trials suggest efficacy for the treatment of delirium in the intensive care unit setting with efficacy comparable to haloperidol and benzodiazepines. Dexmedetomidine also has an opioid-sparing action and can act to enhance analgesia. The purpose of this article is to review the pharmacodynamics and pharmacology of dexmedetomidine, and examine its potential use in the palliative care population, especially with regard to the management of delirium.

An approach to the patient with substance use and abuse

Substance use is ubiquitous among medically ill patients. The 2008 National Survey on Drug Abuse and Health survey estimated that 20.1 million Americans aged 12 years or older (8% of the US population) had used an illicit drug during the preceding month. Some licit substances also create havoc. The survey found that slightly more than half (56%) of Americans reported being current drinkers of alcohol. A total of 6.2 million (2.5%) Americans used prescription-type psychotherapeutic drugs for nonmedical purposes and 70.9 million Americans (or 28.4%) used tobacco during the survey period. Substance abuse problems were diagnosed in up to 36% of medically hospitalized patients for whom a psychiatric consultation was requested. Given how prevalent the use of substances is among the medically ill and their potential effect on comorbid medical conditions, it is important for physicians to be mindful of their prevalence and presentation. This article covers the presenting symptoms of intoxication and withdrawal states, addresses the acute management of the most commonly encountered substances, and summarizes all others in a table.

Dexmedetomidine: pediatric pharmacology, clinical uses and safety

IMPORTANCE OF THE FIELD

Dexmedetomidine is an α(2)-adrenoceptor agonist with sedative, anxiolytic and analgesic properties. It is used off-label in pediatric patients due to its efficacy and lack of adverse respiratory effects. Dexmedetomidine may cause severe circulatory complications in adults. Despite its popularity, the safety of dexmedetomidine in the pediatric population has not been extensively studied.

AREAS COVERED IN THIS REVIEW

This article reviews the current literature (up to 2010) focusing on applications and safety of dexmedetomidine administered to pediatric patients.

WHAT THE READER WILL GAIN

Dexmedetomidine is a useful sedative and anxiolytic drug in the pediatric intensive care unit as well as during diagnostic and therapeutic procedures. Deleterious effects of dexmedetomidine include hypotension and bradycardia. Additionally, hypertension may occur during the "loading dose" or with high infusion rates. Few studies have been performed to evaluate the safety of dexmedetomidine in pediatrics. The development of tolerance and withdrawal has not been studied in children.

TAKE HOME MESSAGE

Despite its favorable respiratory profile, dexmedetomidine may cause deleterious cardiovascular effects. Close monitoring of circulatory dynamics and judicious titration is recommended. Further studies are needed to better define adverse effects following long-term infusions as well as in special populations such as pre-term infants.

Tolerance and withdrawal from prolonged opioid use in critically ill children

OBJECTIVE

After prolonged opioid exposure, children develop opioid-induced hyperalgesia, tolerance, and withdrawal. Strategies for prevention and management should be based on the mechanisms of opioid tolerance and withdrawal.

PATIENTS AND METHODS

Relevant manuscripts published in the English language were searched in Medline by using search terms "opioid," "opiate," "sedation," "analgesia," "child," "infant-newborn," "tolerance," "dependency," "withdrawal," "analgesic," "receptor," and "individual opioid drugs." Clinical and preclinical studies were reviewed for data synthesis.

RESULTS

Mechanisms of opioid-induced hyperalgesia and tolerance suggest important drug- and patient-related risk factors that lead to tolerance and withdrawal. Opioid tolerance occurs earlier in the younger age groups, develops commonly during critical illness, and results more frequently from prolonged intravenous infusions of short-acting opioids. Treatment options include slowly tapering opioid doses, switching to longer-acting opioids, or specifically treating the symptoms of opioid withdrawal. Novel therapies may also include blocking the mechanisms of opioid tolerance, which would enhance the safety and effectiveness of opioid analgesia.

CONCLUSIONS

Opioid tolerance and withdrawal occur frequently in critically ill children. Novel insights into opioid receptor physiology and cellular biochemical changes will inform scientific approaches for the use of opioid analgesia and the prevention of opioid tolerance and withdrawal.

Dexmedetomidine Use in Pediatric Intensive Care and Procedural Sedation

OBJECTIVE

Dexmedetomidine was approved by the Food and Drug Administration in 1999 for the sedation of adults receiving mechanical ventilation in an intensive care setting. It provides sedation with minimal effects on respiratory function and may be used prior to, during, and following extubation. Based on its efficacy in adults, dexmedetomidine is now being explored as an alternative or adjunct to benzodiazepines and opioids in the pediatric intensive care setting. This review describes the studies evaluating the safety and efficacy dexmedetomidine in infants and children and provides recommendations on dosing and monitoring.

METHODS

The MEDLINE (1950–November 2009) database was searched for pertinent abstracts, using the key term dexmedetomidine. Additional references were obtained from the bibliographies of the articles reviewed and the manufacturer. All available English-language case reports, clinical trials, retrospective studies, and review articles were evaluated.

RESULTS

Over two dozen case series and clinical studies have documented the utility of dexmedetomidine as a sedative in children requiring mechanical ventilation or procedural sedation. In several papers, dexmedetomidine use resulted in a reduction in the dose or discontinuation of other sedative agents. It may be of particular benefit in children with neurologic impairment or in those who do not tolerate benzodiazepines. The most frequent adverse effects reported with dexmedetomidine have been hypotension and bradycardia, in 10% to 20% of patients. These effects typically resolve with dose reduction.

CONCLUSIONS

Dexmedetomidine offers an additional choice for the sedation of children receiving mechanical ventilation in the intensive care setting or requiring procedural sedation. While dexmedetomidine is well tolerated when used at recommended doses, it has the potential to cause hypotension and bradycardia and requires close monitoring. In addition to clinical trials currently underway, larger controlled studies are needed to further define the role of dexmedetomidine in pediatric intensive care.

Withdrawal from multiple sedative agent therapy in an infant: is dexmedetomidine the cause or the cure?

OBJECTIVE

To report withdrawal symptoms experienced by an infant following the prolonged use of dexmedetomidine.

DESIGN

Case report.

SETTING

Pediatric intensive care unit at a freestanding tertiary care children's hospital.

PATIENTS

One pediatric patient with respiratory failure following pertussis infection that required prolonged intubation and sedation. The patient required dexmedetomidine to maintain optimal sedation before ventilator weaning. Subsequent to receiving dexmedetomidine the patient developed withdrawal symptoms.

CONCLUSION

In patients who fail to achieve adequate sedation with the use of traditional medications, dexmedetomidine is an adequate alternative. However, abrupt discontinuation of dexmedetomidine may result in withdrawal symptoms that may be avoided with a dexmedetomidine taper.

α2-Receptor Agonists for Treatment and Prevention of Iatrogenic Opioid Abstinence Syndrome in Critically Ill Patients

Objective:

To review the literature regarding the use of α2-agonists in the treatment and prevention of iatrogenic opioid abstinence syndrome (IOAS) in critically ill patients.

Data Sources:

Primary literature was identified through a search of MEDLINE (1950–June 2009), EMBASE (1988–June 2009), International Pharmaceutical Abstracts (1970–June 2009), and the Cochrane Library (1996–June 2009), using the names of individual α2-agonists and the following key words: children, opioid withdrawal, opioid, and adult. Relevant abstracts from the Society of Critical Care Medicine, reference citations from selected articles, and manufacturers’ product information were also reviewed.

Study Selection and Data Extraction:

All English-language articles identified from the data sources were evaluated. Three retrospective studies and 6 case reports/series representing 44 patients were included for analysis.

Data Synthesis:

Central α2-agonists are thought to minimize symptoms of IOAS by decreasing presynaptic outflow of catecholamines. Successful use of clonidine and dexmedetomidine for management of IOAS has been reported. Lofexidine, an α2-agonist not yet approved in the US, may offer similar withdrawal symptom relief but has yet to be studied in the intensive care setting. Although the quality of studies identified was limited, preliminary evidence does provide some support for the use of transdermal clonidine and injectable dexmedetomidine in the treatment and prevention of IOAS. These agents were shown to facilitate discontinuation of opioids and to minimize withdrawal symptoms with few reported adverse events.

Conclusions:

Central α2-agonists appear to be effective and safe second-line agents for treatment and prevention of IOAS. Further studies should be conducted to determine their role in the therapy of patients with IOAS.

Sedation and analgesia in the pediatric intensive care unit following laryngotracheal reconstruction

BACKGROUND

Children undergoing laryngotracheal reconstruction (LTR) may remain electively intubated in the pediatric intensive care unit (PICU) for several days following surgery to facilitate wound healing. These patients require sedation and analgesia with or without neuromuscular blockade in order to prevent excessive head and neck movement with resultant tension on the tracheal anastomosis. Achieving this level of immobility features in caring for these children.

AIM

The aims of this article are to describe a variety of commonly used sedation and analgesic agents and to provide guidance as to their optimal use following LTR.

Sedation and analgesia in the pediatric Intensive Care Unit following laryngotracheal reconstruction

Deep levels of sedation and analgesia are needed in the majority of children who require prolonged tracheal intubation after laryngotracheal reconstruction (LTR). Drug doses may be determined most appropriately using validated scoring tools for sedation and analgesia; these scales continue to evolve and are used with increasing regularity in the pediatric intensive care unit (PICU). In this presentation, the validated scoring tools used to assess sedation and analgesia are reviewed, and specific agents used to manage sedation, analgesia, and neuromuscular blockade in the PICU after LTR are discussed.

[Weaning from the ventilator modalities and consequences]

Only few studies have focused on the issues raised by discontinuing sedation in ICU patients. Several lines of evidence allow defining the risk factors for the occurrence of a weaning syndrome due to discontinuation of sedatives and analgesics in ICU patients. These primarily include a prolonged (more than seven days) period of continuous intravenous administration of high doses of hypnotics and opioids. Weaning from sedation is tightly linked to weaning from the ventilator and this area should be the target of research work in the near future.

Clinical uses of dexmedetomidine in pediatric patients

Dexmedetomidine is being used off-label as an adjunctive agent for sedation and analgesia in pediatric patients in the critical care unit and for sedation during non-invasive procedures in radiology. It also has a potential role as part of anesthesia care to prevent emergence delirium and postanesthesia shivering. Dexmedetomidine is currently approved by the US FDA for sedation only in adults undergoing mechanical ventilation for <24 hours. Pediatric experiences in the literature are in the form of small studies and case reports. In patients sedated for mechanical ventilation and/or opioid/benzodiazepine withdrawal, the loading dose ranged from 0.5 to 1 microg/kg and was usually administered over 10 minutes, although not all patients received loading doses. This patient group also received a continuous infusion at rates ranging from 0.2 to 2 microg/kg/h, with higher rates used in burn patients and those with withdrawal following > or =24 hours of opioid/benzodiazepine infusion. The dexmedetomidine dosage used for anesthesia and sedation during non-invasive procedures, such as radiologic studies, ranged from a loading dose of 1-2 microg/kg followed by a continuous infusion at 0.5-1.14 microg/kg/h, with most patients spontaneously breathing. For invasive procedures, such as awake craniotomy or cardiac catheterization, dosage ranged from a loading dose of 0.15 to 1 microg/kg followed by a continuous infusion at 0.1-2 microg/kg/h. Adverse hemodynamic and respiratory effects were minimal; the agent was well tolerated in most patients. The efficacy of dexmedetomidine varied depending on the clinical situation: efficacy was greatest during non-invasive procedures, such as magnetic resonance imaging (MRI), and lowest during invasive procedures, such as cardiac catheterization. Dexmedetomidine may be useful in pediatric patients for sedation in a variety of clinical situations. The literature suggests potential use of dexmedetomidine as an adjunctive agent to other sedatives during mechanical ventilation and opioid/benzodiazepine withdrawal. In addition, because of its minimal respiratory effects, dexmedetomidine has also been used as a single agent for sedation during non-invasive procedures such as MRI. However, additional studies in pediatric patients are warranted to further evaluate its safety and efficacy in all age ranges.

Use of dexmedetomidine for sedation of children hospitalized in the intensive care unit

BACKGROUND

Dexmedetomidine is a potentially useful sedative for hospitalized children, but there is little published data regarding its safety, dosage, or efficacy.

OBJECTIVE

To report our experience with dexmedetomidine for the sedation of hospitalized children.

DESIGN

Retrospective case series.

SETTING

Pediatric ICU of a university-affiliated children's hospital.

PATIENTS

We retrospectively examined data from the medical records of all children who received dexmedetomidine for sedation between December 2003 and October 2005.

INTERVENTION

None.

RESULTS

Dexmedetomidine was administered 74 times to 60 children (median age 1.5 years, range 0.1-17.2 years). The most common indications for ICU admission were respiratory distress/failure (53%), status-postcorrective cardiac surgery (19%), and other postoperative patients (18%). In 53% of cases dexmedetomidine was used to supplement ongoing sedation judged inadequate and in 41% of cases it was used as a bridge to extubation while other sedatives were weaned or discontinued. Among all the children, the median dose to maintain adequate sedation was 0.7 microg/kg per hour (range 0.2-2.5 microg/kg per hour), with a median duration of therapy of 23 hours (range 3-451 hours). Most children (80%) experienced no adverse effects from the sedation, with hypotension (9%), hypertension (8%), and bradycardia (3%) the most common adverse events. For 93% of children who experienced a side effect, it resolved either without treatment or by withholding the infusion.

CONCLUSIONS

In this cohort of children hospitalized in the ICU, dexmedetomidine appeared to be effective and to have few adverse effects. Dexmedetomidine may have a potentially useful role to play in sedating hospitalized children.

Opioid analgesia in neonates following cardiac surgery

Pain in the newborn is complex, involving a variety of receptors and mechanisms within the developing nervous system. When pain is generated, a series of sequential neurobiologic changes occur within the central nervous system. If pain is prolonged or repetitive, the developing nervous system could be permanently modified, with altered processing at spinal and supraspinal levels. In addition, pain is associated with a number of adverse physiologic responses that include alterations in circulatory (tachycardia, hypertension, vasoconstriction), metabolic (increased catabolism), immunologic (impaired immune response), and hemostatic (platelet activation) systems. This "stress response" associated with cardiac surgery in neonates could be profound and is associated with increased morbidity and mortality. Neonates undergoing cardiac operations are exposed to extensive tissue damage related to surgery and additional painful stimulation related to endotracheal and thoracostomy tubes that may remain in place for variable periods of time following surgery. In addition, postoperatively neonates endure repeated procedural pain from suctioning of endotracheal tubes, placement of vascular catheters, and manipulation of wounds (eg, sternal closure) and dressings. The treatment and/or prevention of pain are widely considered necessary for humanitarian and physiologic reasons. Improved clinical and developmental outcomes underscore the importance of providing adequate analgesia for newborns who undergo major surgery, mechanical ventilation, and related procedures in the intensive care unit. This article reviews published information regarding opioid administration and associated issues of tolerance and abstinence syndromes (withdrawal) in neonates with an emphasis on those having undergone cardiac surgery.

Hypothermia-induced bradycardia in a neonate receiving dexmedetomidine

Dexmedetomidine, an alpha(2)-adrenergic agonist, decreases lipolysis and thus prevents nonshivering thermogenesis in infants. We report the case of a two-day-old neonate who received dexmedetomidine for sedation and analgesia after undergoing primary repair of bladder exstrophy. After 9 hours, the patient developed bradycardia and profound hypothermia. The bradycardia was unresponsive to anticholinergics but resolved approximately two hours after radiant heat was applied. This report highlights the potential profound impact of dexmedetomidine on thermoregulation in neonates. Dexmedetomidine impacts thermoregulation in neonates and its use warrants careful attention to the control of temperature and to the routine use of exogenous heat.

Dexmedetomidine for the treatment of postanesthesia shivering in children

BACKGROUND

Shivering is a common postanesthesia adverse event with multiple etiologies and multiple suggested prophylactic and abortive treatment regimens. Dexmedetomidine, a centrally acting alpha(2)-adrenergic agonist, has been used as a sedative agent and is known to reduce the shivering threshold. We hypothesized that children with postanesthesia shivering would reduce shivering behavior following a single bolus dose of dexmedetomidine.

METHODS

Dexmedetomidine was administered in a prospective, open-label fashion. The anesthesia management was uniform consisting of maintenance inhaled anesthesia (sevoflurane) and the intraoperative administration of fentanyl (1-2 microg.kg(-1)) plus a regional anesthetic technique (either a neuraxial or peripheral block) for postoperative analgesia. Criteria for treatment included: (i) shivering, (ii) successful extubation, and (iii) no other complaint/indication of pain. All children who met the criteria were treated with a single intravenous bolus dose of dexmedetomidine (0.5 microg.kg(-1)) over 3-5 min. Following the completion of drug administration, shivering activity was recorded every minute (up to 10 min) with any adverse effects or complaints. The efficacy of shivering reduction at 5 min in this cohort is compared with previous reports from the literature of the efficacy of clonidine and meperidine.

RESULTS

Twenty-four children ranging in age from 7 to 16 years (11.5 +/- 2.5 years) were treated. All children had a cessation of shivering behavior within 5 min following the completion of dexmedetomidine administration. The onset of effect was 3.5 +/- 0.9 min. No adverse effects were observed. No shivering behavior recurred.

CONCLUSIONS

This study demonstrates the efficacy of dexmedetomidine in the treatment of postanesthesia shivering.

Dexmedetomidine: applications in pediatric critical care and pediatric anesthesiology

OBJECTIVE

To provide a general descriptive account of the end-organ effects of dexmedetomidine and to provide an evidence-based review of the literature regarding its use in infants and children.

DATA SOURCE

A computerized bibliographic search of the literature regarding dexmedetomidine.

MAIN RESULTS

The end-organ effects of dexmedetomidine have been well studied in animal and adult human models. Adverse cardiovascular effects include occasional episodes of bradycardia with rare reports of sinus pause or cardiac arrest. Hypotension has also been reported as well as hypertension, the latter thought to be due to peripheral alpha2B agonism with peripheral vasoconstriction. Although dexmedetomidine has no direct effects on myocardial function, decreased cardiac output may result from changes in heart rate or increases in afterload. There are somewhat conflicting reports in the literature regarding its effects on ventilatory function, with some studies (both human and animal) suggesting a mild degree of respiratory depression, decreased minute ventilation, and decreased response to CO2 challenge whereas others demonstrate no effect. The central nervous system effects include sedation and analgesia with prevention of recall and memory at higher doses. Dexmedetomidine may also provide some neuroprotective activity during periods of ischemia. Applications in infants and children have included sedation during mechanical ventilation, prevention of emergence agitation following general anesthesia, provision of procedural sedation, and the prevention of withdrawal following the prolonged administration of opioids and benzodiazepines.

CONCLUSIONS

The literature contains reports of the use of dexmedetomidine in approximately 800 pediatric patients. Given its favorable sedative and anxiolytic properties combined with its limited effects on hemodynamic and respiratory function, there is growing interest in and reports of its use in the pediatric population in various clinical scenarios.

Dexmedetomidine: an updated review

OBJECTIVE

To review recent literature on the safety and efficacy of dexmedetomidine.

DATA SOURCES

Articles were identified through searches of MEDLINE (1966-January 2007). Key words included dexmedetomidine, medetomidine, alpha(2)-agonist, and sedation. References from selected articles were reviewed for additional references.

STUDY SELECTION AND DATA EXTRACTION

Experimental and observational studies that focused on the safety and efficacy of dexmedetomidine in humans were selected.

DATA SYNTHESIS

Dexmedetomidine is an alpha(2)-agonist for short-term sedation in critically ill patients. In postoperative patients, dexmedetomidine produced similar levels of sedation and times to extubation, with less opioid requirements compared with propofol. Dexmedetomidine has also been studied for sedation in critically ill medical and pediatric patients, as adjunct to anesthesia, and for procedural sedation. Hypotension, hypertension, and bradycardia are common adverse effects. Although dexmedetomidine is labeled only for sedation less than 24 hours, it has been administered for longer than 24 hours without apparent development of rebound hypertension and tachycardia.

CONCLUSIONS

Dexmedetomidine is a safe and effective agent for sedation in critically ill patients. Further, well designed studies are needed to define its role as a sedative for critically ill medical, neurosurgical, and pediatric patients, as an adjunct to anesthesia, and as a sedative during procedures.

Short Duration Large Dose Dexmedetomidine in a Pediatric Patient During Procedural Sedation

We describe an infusion of dexmedetomidine at 1.0 microg.kg(-1).min(-1) for 10 min (total dose, 144 microg) sedation in a 3-yr-old child weighing 14 kg. The large dose of dexmedetomidine produced a hemodynamically stable patient who was deeply sedated for approximately 4 h after discontinuing the infusion.

Adverse responses: sedation, analgesia and neuromuscular blocking agents in critically ill children

Advanced practice nurses (APNs) prescribe sedation, analgesia, and neuromuscular blocking agents in the management of critically ill children. Although most children are unscathed from the use of the medications, some suffer adverse responses. This article elucidates adverse responses to these medications for the APN, including withdrawal syndrome, muscle weakness, decreased gastric motility, corneal abrasions, and costs associated with these morbidities.

The use of dexmedetomidine to facilitate acute discontinuation of opioids after cardiac transplantation in children

OBJECTIVE

To report the use of dexmedetomidine to facilitate rapid opioid and benzodiazepine withdrawal in children with transplanted hearts and to review the receptor physiology and pharmacodynamic impact of dexmedetomidine on the denervated heart.

DESIGN

Case series.

SETTING

Intensive care unit at a tertiary pediatric medical center.

PATIENTS

The series included a 6-month-old infant with pulmonary atresia who had a 3-month exposure to high-dose opioids and benzodiazepines and had undergone cardiac transplantation 4 wks before the use of dexmedetomidine and a 7-yr-old boy who had been sedated while undergoing extracorporeal membrane oxygenation for 3 wks before transplantation and started to receive dexmedetomidine 3 days after transplantation.

INTERVENTION

Administration of dexmedetomidine to facilitate the discontinuation of opioids and benzodiazepine.

MAIN RESULT

Successful rapid withdrawal from opioids and benzodiazepines while maintaining hemodynamic stability.

CONCLUSION

To our knowledge, this report describes the first use of dexmedetomidine to facilitate opioid withdrawal in children with a cardiac transplant. Dexmedetomidine allowed for the preservation of satisfactory hemodynamic parameters during acute withdrawal from opioids in children with denervated hearts.

Tolerance and Withdrawal Issues with Sedation

The stay in an ICU is a complex mixture of providing optimal care while keeping the patient safe. Means of reducing the anxiety associated with the ICU stay include frequent reorientation and maintenance of patient comfort with sedation supplemented by analgesia as needed. The most common agents used to provide sedation include benzodiazepines, propofol, and the newer dexmedetomidine. Others include barbiturate agents, neuroleptics, clonidine, etomidate, ketamine, and supplemental opioid analgesics for pain control. A common complication of sedation is tolerance, which can lead to withdrawal if the sedation is discontinued hastily. This article evaluates the occurrence of tolerance and withdrawal in the most commonly used sedatives in critically ill patients.

Dexmedetomidine in anaesthesia

PURPOSE OF REVIEW

The development of dexmedetomidine, a potent and highly selective alpha2-adrenoceptor agonist, has created new interest in the use of alpha2-adrenoceptor agonists, and has led to its evaluation in various yet non-approved perioperative settings. The current review focuses on the usefulness of dexmedetomidine in anaesthesia practice.

RECENT FINDINGS

Recently acquired knowledge and experience with dexmedetomidine in perioperative use will be presented and discussed in the context of known pharmacological properties.

SUMMARY

Dexmedetomidine offers beneficial pharmacological properties, providing dose-dependent sedation, analgesia, sympatholysis and anxiolysis without relevant respiratory depression. The side-effects are predictable from the pharmacological profile of (2-adrenoceptor agonists. In particular, the unique sedative properties of dexmedetomidine resulted in several interesting applications in anaesthesia practice, promising benefits in the perioperative use of this compound. However, dexmedetomidine was approved for sedation in the intensive care unit in the USA in 1999, and administration in anaesthesia practice remains an 'off-label' use. Further studies are needed to establish the role of dexmedetomidine in the perioperative period.