Dexmedetomidine in the Treatment of Withdrawal Syndromes in Cardiothoracic Surgery Patients

Dexmedetomidine in the treatment of toxicologic conditions: a systematic review and review of the toxicology investigators consortium database

INTRODUCTION

Dexmedetomidine is an alpha-2 adrenoceptor agonist which is widely used for sedation. Dexmedetomidine does not suppress the respiratory drive and produces a state of cooperative sedation; it may be associated with beneficial outcomes in the general critical care population. The role of dexmedetomidine in the treatment of toxicologic conditions (excluding alcohol withdrawal) is unclear.

OBJECTIVES

To critically assess and summarize the literature regarding the use of dexmedetomidine in toxicologic conditions other than alcohol withdrawal.

METHODS

We performed a systematic review of the medical literature to identify all existing evidence regarding the use of dexmedetomidine for toxicologic conditions. We excluded reviews and commentary, studies reporting exclusively on alcohol withdrawal, and studies reporting the use of dexmedetomidine to treat iatrogenic sedative withdrawal in the intensive care unit. We also performed a review of the Toxicology Investigators Consortium (ToxIC) database for patients treated with dexmedetomidine.

RESULTS

We identified 98 studies meeting inclusion criteria; 87 of these were case reports or case series, representing 99 unique cases. Eleven articles with other designs were identified, which included 138 patients treated with dexmedetomidine for toxicologic conditions. Ninety-three cases from the ToxIC registry met inclusion criteria. Common indications for dexmedetomidine included stimulant intoxication, sedative withdrawal, serotonin syndrome, antimuscarinic toxidrome, opioid withdrawal, and cannabinoid intoxication. Dexmedetomidine was usually administered by continuous infusion; bolus administration was reported in a minority of cases. Adverse effects were uncommon. The quality of evidence was generally low, given the preponderance of case reports, the rate of missing or poorly reported data, and the near-universal co-administration of other sedatives.

TREATMENT OF STIMULANT POISONING

Fifty-nine patients with stimulant poisoning were treated with dexmedetomidine. There was reasonably good evidence that dexmedetomidine was helpful in the treatment of stimulant poisoning.

TREATMENT OF SEDATIVE WITHDRAWAL

Twenty-two patients with sedative withdrawal were treated with dexmedetomidine. Several case reports of very high-quality suggested efficacy of dexmedetomidine for this indication, particularly for baclofen withdrawal.

TREATMENT OF SEROTONIN SYNDROME

Twenty-six patients with serotonin syndrome were treated with dexmedetomidine. This evidence was of lower quality due to missing clinical details, potential overdiagnosis of serotonin syndrome, and near-universal concomitant treatment with other sedatives.

TREATMENT OF ANTIMUSCARINIC POISONING

Forty-two patients with antimuscarinic poisoning were treated with dexmedetomidine. This evidence was of low quality and was limited by infrequent use of the preferred antidote, physostigmine.

TREATMENT OF OPIOID WITHDRAWAL

Forty-four patients with opioid withdrawal were treated with dexmedetomidine. This evidence was of low quality due to missing clinical details and near-universal concomitant treatment with other agents. The one high-quality trial reported the use of dexmedetomidine in ultra-rapid opioid detoxification, which is not indicated in modern practice.

TREATMENT OF CANNABINOID INTOXICATION

Five patients with cannabinoid intoxication were treated with dexmedetomidine. No definite conclusion can be drawn from the limited available evidence.

DISCUSSION

It is important to distinguish between the use of dexmedetomidine as a general sedative, which is likely to increase as the overall utilization of dexmedetomidine in critical care settings increases, and the use of dexmedetomidine as a specific pharmacologic treatment for a toxicologic condition. Well-established pharmacologic data from animal and human studies suggest dexmedetomidine counteracts stimulant-induced norepinephrine release. The mechanism by which dexmedetomidine treats sedative withdrawal is unclear. Some animal data show that dexmedetomidine may indirectly suppress serotonin release, which may suggest a role for dexmedetomidine in this condition.

CONCLUSIONS

There is a small and generally low-quality body of evidence which suggests that dexmedetomidine may be helpful in the treatment of certain toxicologic conditions, particularly stimulant intoxication and sedative withdrawal. Further high-quality research is needed to clarify the role of dexmedetomidine in patients with toxicologic conditions.

Dexmedetomidine for prevention of opioid/benzodiazepine withdrawal syndrome in pediatric intensive care unit: Interim analysis of a randomized controlled trial

STUDY OBJECTIVE

Withdrawal syndrome (WS) may be a critical drawback of opioid/benzodiazepine weaning in children. The most effective intervention to reduce WS prevalence is yet to be determined. Dexmedetomidine (DEX) was estimated to be effective in reducing WS-related symptoms, but no randomized trial has been conducted to prove its efficacy so far. We aimed to evaluate the efficacy and safety of DEX in reducing the occurrence of WS.

DESIGN AND SETTING

This was an adaptive randomized double-blind placebo-controlled trial conducted at three Italian Pediatric Intensive Care Units (PICUs).

PATIENTS

It included children admitted to PICU, undergoing at least five days of opioids/benzodiazepines continuous infusion, and ready to start the analgosedation weaning.

INTERVENTION

Twenty-four hours before the start of weaning, an infusion of DEX/placebo was started. WS symptoms were monitored using the Withdrawal-Assessment-Tool-version-1 (WAT-1). In case of WS symptoms (WAT-1 ≥ 3) an opioid/benzodiazepine bolus was given and the DEX/placebo infusion-rate was increased.

MEASUREMENTS

The primary outcome measure was the prevalence of WS. Secondary outcomes were the trend of WAT-1 over time, number of rescue doses, length of weaning and PICU-stay, and onset of adverse events (AEs).

MAIN RESULTS

Forty-five patients were enrolled, of whom 5 dropped-out and 40 entered the interim analysis. There were no significant baseline differences between groups. WS prevalence did not significantly differ between groups (77.8% DEX vs 90.9% placebo, p = 0.381). By generalized linear mixed modeling, the WAT-1 trend showed a significant increase per unit of time in the DEX arm (estimate 0.27, CI 0.07-0.47, p = 0.009) compared to placebo. Most frequent AEs were hemodynamic, and all of them happened in the DEX arm.

CONCLUSIONS

A continuous infusion of DEX, started 24 h before the analgosedation weaning and increased based on WS signs, was not able to significantly modify the prevalence of WS in children who received at least five days of opioids/benzodiazepines treatment compared to placebo.

The Safety and Efficacy Evaluation of Dexmedetomidine for Procedural Sedation and Postoperative Behaviors in Pediatric Populations: A Systematic Review and Meta-analysis

BACKGROUND

This study systematically evaluated the safety and efficacy of dexmedetomidine for procedural sedation and postoperative behaviors in a pediatric population as well as whether the results met the information required to draw conclusions.

OBJECTIVE

To evaluate the safety and efficacy evaluation of dexmedetomidine for procedural sedation and postoperative behaviors in a pediatric population.

METHODS

PubMed, Cochrane library, Web of Science and Ovid MEDLINE were searched to obtain randomized controlled trials (RCTs) comparing dexmedetomidine with control medicine and comparing different doses of dexmedetomidine.

RESULTS

There were a total of 16 RCTs for a total of 3240 patients. Dexmedetomidine slowed down the heart rate (HR; mean difference: -13.27; 95% CI: -16.41 to 10.14; P < 0.001) and reduced postoperative delirium (risk ratio [RR]: 0.31; 95% CI: 0.20-0.50; P < 0.001), the number of pain patients (RR: 0.48; 95% CI: 0.30-0.75; P = 0.002), and desaturation (RR: 0.34; 95% CI: 0.13-0.89; P = 0.03) compared with the control group. The limitation was that it was difficult to determine the range of low- and high-dose dexmedetomidine.

CONCLUSION AND RELEVANCE

Dexmedetomidine slowed down intraoperative HR within the normal range, which might reduce myocardial oxygen consumption. It reduced postoperative pain and postoperative complications: delirium and desaturation. Dexmedetomidine showed no dose-dependent increase in the procedural sedation time of pediatric patients. Clinically, dexmedetomidine can improve pediatric procedural sedation and postoperative behavior, and it can be considered as a related medicine for safety in pediatric surgery.

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.

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

Background

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

Methods

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

Discussion

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

Trial registration

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

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

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.

Pharmacokinetics and pharmacodynamics of dexmedetomidine

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

Treatment of Severe Alcohol Withdrawal

OBJECTIVE

Approximately 50% of patients with alcohol dependence experience alcohol withdrawal. Severe alcohol withdrawal is characterized by seizures and/or delirium tremens, often refractory to standard doses of benzodiazepines, and requires aggressive treatment. This review aims to summarize the literature pertaining to the pharmacotherapy of severe alcohol withdrawal.

DATA SOURCES

PubMed (January 1960 to October 2015) was searched using the search termsalcohol withdrawal, delirium tremens, intensive care, andrefractory Supplemental references were generated through review of identified literature citations.

STUDY SELECTION AND DATA EXTRACTION

Available English language articles assessing pharmacotherapy options for adult patients with severe alcohol withdrawal were included.

DATA SYNTHESIS

A PubMed search yielded 739 articles for evaluation, of which 27 were included. The number of randomized controlled trials was limited, so many of these are retrospective analyses and case reports. Benzodiazepines remain the treatment of choice, with diazepam having the most favorable pharmacokinetic profile. Protocolized escalation of benzodiazepines as an alternative to a symptom-triggered approach may decrease the need for mechanical ventilation and intensive care unit (ICU) length of stay. Propofol is appropriate for patients refractory to benzodiazepines; however, the roles of phenobarbital, dexmedetomidine, and ketamine remain unclear.

CONCLUSIONS

Severe alcohol withdrawal is not clearly defined, and limited data regarding management are available. Protocolized administration of benzodiazepines, in combination with phenobarbital, may reduce the need for mechanical ventilation and lead to shorter ICU stays. Propofol is a viable alternative for patients refractory to benzodiazepines; however, the role of other agents remains unclear. Randomized, prospective studies are needed to clearly define effective treatment strategies.

Dexmedetomidine for acute baclofen withdrawal

BACKGROUND

Intrathecal baclofen is widely accepted as a treatment option for severe spasticity through its γ-Aminobutyric acid-B (GABAB ) agonist properties. Abrupt cessation can lead to severe and life-threatening withdrawal characterized by altered mental status, autonomic dysreflexia, rigidity, and seizures. This symptomatic presentation is similar to alcohol withdrawal, which is mediated by modification of GABAA expression. Use of the α2-adrenergic agonist dexmedetomidine for the treatment of ethanol withdrawal has been widely reported, raising the question of its potential role in baclofen withdrawal. We present a case of the successful treatment of acute severe baclofen withdrawal with a dexmedetomidine infusion.

METHODS

A 15-year-old patient with spastic quadriparesis and cerebral palsy underwent unexpected removal of his baclofen pump due to an infection that was encountered during a planned pump revision. Following removal, he was placed on high dose enteral baclofen every 6 h. Despite further benzodiazepine supplementation, he had progressive hemodynamic instability, severe rebound spasticity, and intermittent spontaneous clonus consistent with baclofen withdrawal. A dexmedetomidine infusion was titrated to a peak dose of 16 mcg per hour with successful treatment of withdrawal symptoms.

RESULTS

The patient became normotensive without tachycardia. Tone and agitation improved.

CONCLUSION

Dexmedetomidine is to our knowledge a previously unreported option for treatment of acute severe baclofen withdrawal. We report a case of safe and efficacious use in a patient with spastic quadriparesis on chronic intrathecal baclofen. Scientifically rigorous comparison with other options remains to be performed.

A randomized, double-blind, placebo-controlled dose range study of dexmedetomidine as adjunctive therapy for alcohol withdrawal

OBJECTIVES

To evaluate dexmedetomidine as adjunctive therapy to lorazepam for severe alcohol withdrawal.

DESIGN

Prospective, randomized, double-blind, placebo-controlled trial.

SETTING

Single center; medical ICU.

PATIENTS

Twenty-four adult patients with a Clinical Institute Withdrawal Assessment score greater than or equal to 15 despite greater than or equal to 16 mg of lorazepam over a 4-hour period.

INTERVENTIONS

Patients received a symptom-triggered Clinical Institute Withdrawal Assessment protocol with lorazepam and were randomized to dexmedetomidine 1.2 μg/kg/hr (high dose), 0.4 μg/kg/hr (low dose), or placebo as adjunctive therapy for up to 5 days or resolution of withdrawal symptoms.

MEASUREMENT AND MAIN RESULTS

High-dose and low-dose groups were combined as a single dexmedetomidine group for primary analysis with secondary analysis exploring a dose-response relationship. The difference in 24-hour lorazepam requirements after versus before study drug was greater in the dexmedetomidine group compared with the placebo group (-56 mg vs -8 mg, p = 0.037). Median differences were similar for high dose and low dose. The 7-day cumulative lorazepam requirements were not statistically different between dexmedetomidine and placebo (159 mg vs 181 mg). Clinical Institute Withdrawal Assessment or Riker sedation-agitation scale scores representing severe agitation (13% vs 25%) or moderate agitation (27% vs 22%) within 24 hours of initiating study drug were similar for dexmedetomidine and placebo groups, respectively. Bradycardia occurred more frequently in the dexmedetomidine group versus placebo group (25% vs 0%, p = not significant), with the majority of bradycardia occurring in the high-dose group (37.5%). Study drug rate adjustments occurred more often in the dexmedetomidine group compared with the placebo group (50% vs 0%, p = 0.02). Neither endotracheal intubation nor seizure occurred in any group while on study drug.

CONCLUSIONS

Adjunctive dexmedetomidine for severe alcohol withdrawal maintains symptom control and reduces lorazepam exposure in the short term, but not long term, when using a symptom-triggered protocol. Monitoring for bradycardia is needed with dexmedetomidine but the occurrence may be lessened with low dose. Further study is needed to evaluate the clinical impact of dexmedetomidine.

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.

Inflammatory Response in Patients under Coronary Artery Bypass Grafting Surgery and Clinical Implications: A Review of the Relevance of Dexmedetomidine Use

Despite the fact that coronary artery bypass grafting surgery (CABG) with cardiopulmonary bypass (CPB) prolongs life and reduces symptoms in patients with severe coronary artery diseases, these benefits are accompanied by increased risks. Morbidity associated with cardiopulmonary bypass can be attributed to the generalized inflammatory response induced by blood-xenosurfaces interactions during extracorporeal circulation and the ischemia/reperfusion implications, including exacerbated inflammatory response resembling the systemic inflammatory response syndrome (SIRS). The use of specific anesthetic agents with anti-inflammatory activity can modulate the deleterious inflammatory response. Consequently, anti-inflammatory anesthetics may accelerate postoperative recovery and better outcomes than classical anesthetics. It is known that the stress response to surgery can be attenuated by sympatholytic effects caused by activation of central (α-)2-adrenergic receptor, leading to reductions in blood pressure and heart rate, and more recently, that they can have anti-inflammatory properties. This paper discusses the clinical significance of the dexmedetomidine use, a selective (α-)2-adrenergic agonist, as a coadjuvant in general anesthesia. Actually, dexmedetomidine use is not in anesthetic routine, but this drug can be considered a particularly promising agent in perioperative multiple organ protection.

Influence of dexmedetomidine therapy on the management of severe alcohol withdrawal syndrome in critically ill patients

PURPOSE

Although benzodiazepines are first-line drugs for alcohol withdrawal syndrome (AWS), rapidly escalating doses may offer little additional benefit and increase complications. The purpose of this study was to evaluate dexmedetomidine's impact on benzodiazepine requirements and hemodynamics in AWS.

MATERIALS AND METHODS

This retrospective case series evaluated 33 critically ill adults with a primary diagnosis of AWS from 2006 to 2012 at an academic medical center.

RESULTS

Dexmedetomidine began a median (interquartile range) of 11 (2, 32) hours into intensive care unit admission and was titrated to an infusion rate of 0.7 (0.4, 0.7) μg kg(-1) h(-1) to achieve the desired depth of sedation. In the 12 hours after dexmedetomidine began, patients experienced a 20-mg reduction in median cumulative benzodiazepine dose used (P < .001), a 14-mm Hg lower mean arterial pressure (P = .03), and a 17-beats/min reduction in median heart rate (P < .001). Four (12%) patients experienced hypotension (systolic blood pressure <80 mm Hg) during therapy, and there were no cases of bradycardia (heart rate <40 beats/min).

CONCLUSION

Dexmedetomidine decreased benzodiazepine requirements and improved the overall hemodynamic profile of patients with severe AWS. These results provide promising evidence about the potential benefit of dexmedetomidine for AWS.

A case-based approach to the practical application of dexmedetomidine in critically ill adults

Dexmedetomidine is a selective α(2) -adrenoceptor agonist that offers unique sedation because patients are readily awakened while administration continues and the drug does not suppress the respiratory center. Limitations of use include higher acquisition cost, inability to produce deep sedation, and bradycardia and hypotension. Using a case-based approach, the purpose of this review was to qualitatively assess the role of dexmedetomidine in the care of the critically ill and in the management of alcohol withdrawal, and to formulate recommendations regarding its clinical application. Sixty-six studies were identified that investigated dexmedetomidine for the provision of sedation. These studies were heterogeneous in design and patient populations; most investigated patients did not require heavy sedation, and few used propofol as the comparator. In general, though, the aggregate results of all studies demonstrate that dexmedetomidine provides comfort, possibly shortens the duration of mechanical ventilation to facilitate extubation, reduces the occurrence of acute brain dysfunction, and facilitates communication, but the drug is associated with hemodynamic instability and requires the supplemental use of traditional sedative and analgesic agents. These outcomes need to be substantiated in additional studies that include assessments of cost-effectiveness. Dexmedetomidine should be considered when patients require mild to moderate levels of sedation of short to intermediate time frames, and they qualify for daily awakenings with traditional sedative therapies. The data for dexmedetomidine in relation to alcohol withdrawal are limited to 12 retrospective reports representing a total of 127 patients. Its role for this indication requires further study, but it may be considered as adjunctive therapy when clinicians are concerned about respiratory suppression associated with escalating doses of γ-aminobutyric acid agonists. Regardless of the indication for dexmedetomidine, the practitioner must closely monitor patient comfort and the occurrence of hemodynamic deviations with the realization that as-needed administration of traditional sedatives and analgesics will be required and some degree of bradycardia and hypotension expected but intervention rarely required.

A rational approach to the treatment of alcohol withdrawal in the ED

Approximately 7% of the US population abuses or is dependent on alcohol. Patients with alcohol disorders often seek medical attention in Emergency Departments (EDs) for complications directly related to alcohol use or due to other medical issues associated with alcohol use. Because of increasing lengths of stay in EDs, alcohol-dependent patients are at high risk of developing alcohol withdrawal syndrome (AWS) during their ED visit. This article reviews the physiology of alcohol withdrawal as well as the symptoms of this potentially deadly illness for the practicing emergency physician (EP). We provide evidence-based guidelines for the appropriate ED treatment of moderate to severe AWS, including pharmacologic interventions, adjunctive therapies, and disposition of these patients.

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: current role in anesthesia and intensive care

BACKGROUND AND OBJECTIVES

To update and review the application of dexmedetomidine in anesthesia and intensive care. This study is a comprehensive review of clinical uses, pharmacology, pharmacokinetics, mechanism of action and adverse effects of dexmedetomidine.

CONTENT

The effective use of sedative-hypnotic agents and analgesics is an integral part of comfort and safety of patients. Dexmedetomidine is a potent and highly selective α-2 adrenoceptor agonist with sympatholytic, sedative, amnestic, and analgesic properties, which has been described as a useful and safe adjunct in many clinical applications. It provides a unique "conscious sedation", analgesia, without respiratory depression. The current reviewed uses include sedation at Intensive Care Unit-ICU (both adult and pediatric), emergency department, regional and general anesthesia, neurosurgery, sedation for pediatric procedures, awake fiber-optic intubation, cardiac surgery and bariatric surgery.

CONCLUSIONS

Dexmedetomidine offers a unique ability of providing both sedation and analgesia without respiratory depression. It is a new agent with a wide safety margin, excellent sedative capacity and moderate analgesic properties. Although its wide use is currently in patients of surgical and non-surgical intensive care units, dexmedetomidine seems to have promising future applications in neuroprotection, cardioprotection and renoprotection. More detailed studies are required to define its role as sedative in critical, neurosurgical and pediatric patients, as anesthesia adjunct and sedative during procedures.

Use of dexmedetomidine for the treatment of alcohol withdrawal syndrome in critically ill patients: a retrospective case series

Alcohol withdrawal syndrome (AWS) continues to be a challenge to manage in the ICU setting, and the ideal pharmacological treatment continues to evolve. Dexmedetomidine is a newer agent approved for short-term sedation in the ICU, but its use in the treatment of AWS has been limited. We report a retrospective case series of ten patients who were identified as receiving dexmedetomidine for AWS as designated by electronic pharmacy records. All subjects were male, with a mean age of 53.6 years, and a mean ICU length of stay of 9.3 days. They were all diagnosed with AWS by DSM-IV criteria. All the study patients received dexmedetomidine during their hospital course as a treatment for AWS. Studied variables included demographic data, dose and duration of dexmedetomidine, other pharmaceutical agents, and hemodynamics. Dexmedetomidine was safe to use in all patients, although mechanical ventilation was still required in three patients. With dexmedetomidine, the autonomic hyperactivity was blunted, with a mean 12.8% reduction in rate pressure product observed. Consideration should be given to the combined use of dexmedetomidine with benzodiazepines in the treatment of AWS.

Dexmedetomidine as adjunct treatment for severe alcohol withdrawal in the ICU

BACKGROUND

Patients undergoing alcohol withdrawal in the intensive care unit (ICU) often require escalating doses of benzodiazepines and not uncommonly require intubation and mechanical ventilation for airway protection. This may lead to complications and prolonged ICU stays. Experimental studies and single case reports suggest the α2-agonist dexmedetomidine is effective in managing the autonomic symptoms seen with alcohol withdrawal. We report a retrospective analysis of 20 ICU patients treated with dexmedetomidine for benzodiazepine-refractory alcohol withdrawal.

METHODS

Records from a 23-bed mixed medical-surgical ICU were abstracted from November 2008 to November 2010 for patients who received dexmedetomidine for alcohol withdrawal. The main analysis compared alcohol withdrawal severity scores and medication doses for 24 h before dexmedetomidine therapy with values during the first 24 h of dexmedetomidine therapy.

RESULTS

There was a 61.5% reduction in benzodiazepine dosing after initiation of dexmedetomidine (n = 17; p < 0.001) and a 21.1% reduction in alcohol withdrawal severity score (n = 11; p = .015). Patients experienced less tachycardia and systolic hypertension following dexmedetomidine initiation. One patient out of 20 required intubation. A serious adverse effect occurred in one patient, in whom dexmedetomidine was discontinued for two 9-second asystolic pauses noted on telemetry.

CONCLUSIONS

This observational study suggests that dexmedetomidine therapy for severe alcohol withdrawal is associated with substantially reduced benzodiazepine dosing, a decrease in alcohol withdrawal scoring and blunted hyperadrenergic cardiovascular response to ethanol abstinence. In this series, there was a low rate of mechanical ventilation associated with the above strategy. One of 20 patients suffered two 9-second asystolic pauses, which did not recur after dexmedetomidine discontinuation. Prospective trials are warranted to compare adjunct treatment with dexmedetomidine versus standard benzodiazepine therapy.

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.

Pharmacology of sedative-analgesic agents: dexmedetomidine, remifentanil, ketamine, volatile anesthetics, and the role of peripheral Mu antagonists

In this article, the authors discuss the pharmacology of sedative-analgesic agents like dexmedetomidine, remifentanil, ketamine, and volatile anesthetics. Dexmedetomidine is a highly selective alpha-2 agonist that provides anxiolysis and cooperative sedation without respiratory depression. It has organ protective effects against ischemic and hypoxic injury, including cardioprotection, neuroprotection, and renoprotection. Remifentanil is an ultra-short-acting opioid that acts as a mu-receptor agonist. Ketamine is a nonbarbiturate phencyclidine derivative and provides analgesia and apparent anesthesia with relative hemodynamic stability. Volatile anesthetics such as isoflurane, sevoflurane, and desflurane are in daily use in the operating room in the delivery of general anesthesia. A major advantage of these halogenated ethers is their quick onset, quick offset, and ease of titration in rendering the patient unconscious, immobile, and amnestic.

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.

Dexmedetomidine as an adjuvant analgesic for intractable cancer pain

Abstract Dexmedetomidine (Precedex®) is an alpha-2 adrenergic agonist that can produce sedation and analgesia without causing respiratory depression. Its use has been described in patients undergoing mechanical ventilation, sedation for surgical and nonsurgical procedures, and prevention of withdrawal. We describe its use as an adjuvant analgesic in a patient with cancer pain refractory to multiple treatment modalities.

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.

Alcohol withdrawal in the critical care unit

Managing acute alcohol withdrawal in critical care presents a unique challenge to the critical care nurse. The prominence of alcohol use within the Australian community means that many critical care admissions involve acute alcohol withdrawal, an alcohol induced illness, or indeed an unrelated admission with underlying heavy alcohol intake. Current statistics suggest 1 in 5 Australians drink to 'risky' levels each month. This suggests that most critical care nurses will encounter a patient who is experiencing active withdrawal from alcohol, often without clear physiological symptomatology. Acute alcohol withdrawal delirium can be difficult to distinguish from other forms of delirium and in the absence of a comprehensive history, alcohol withdrawal and its sequelae may go untreated. Contemporary management guidelines for alcohol withdrawal suggest a common framework of first line benzodiazepine usage, with emerging research focusing on adjunctive therapy aimed at reducing benzodiazepine doses, and therefore reducing length of stay in the critical care unit. The controversial therapy of ethanol infusion and common assessment and withdrawal scales are examined in relation to their usefulness in critical care. Alcohol withdrawal management in critical care necessitates careful nursing assessment, including alcohol usage history, delirium management, withdrawal assessment and symptomatic relief using an evidence-based protocol.

Effect of dexmedetomidine on pulmonary artery pressure after congenital cardiac surgery: A pilot study

OBJECTIVE

To characterize the effects of dexmedetomidine on the pulmonary artery pressure in patients after congenital cardiac surgery.

DESIGN

Prospective observational pilot study.

SETTING

Pediatric cardiac intensive care unit at a university hospital.

PATIENTS

Twenty-two patients who received dexmedetomidine after cardiothoracic surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

An echocardiogram was performed at three time points: 1) baseline (T0); 2) 6 mins after dexmedetomidine loading (T1); and 3) 1 hr after initiation of dexmedetomidine infusion (T2). Transthoracic echocardiography was used to estimate pulmonary artery pressure based on tricuspid regurgitant velocity (4 x Velocity2) plus central venous pressure. Twenty-two patients aged 0.9 yrs old (interquartile range, 7.9) were enrolled at a median of 1 hr (1.5) after surgery. Dexmedetomidine loading, 0.62 microg/kg (0.5), was given in all patients followed by 0.5 microg/kg/hr (0.6) at T1 and 0.65 microg/kg/hr (0.5) at T2. None of the patients had any increase in pulmonary artery pressure. Overall, the pulmonary artery pressure decreased from 30 mm Hg (13) at T0 to 24 mm Hg (10) at T1 and 26 mm Hg (8) at T2 (p < .001). The pulmonary artery pressure/systemic systolic blood pressure ratio decreased from 33% (12) at T0 to 23% (15) at T1 and 25% (13) at T2 (p = .002). There was no difference in the left ventricular function, Fio2, oxygen %, Po2, CO2, and vasoactive agents.

CONCLUSIONS

Administration of dexmedetomidine after congenital cardiac surgery was not associated with any increase in pulmonary artery pressure.

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.

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.

Perioperative hypertension: a review of current and emerging therapeutic agents

Perioperative hypertension is a common problem encountered by anesthesiologists, surgeons, internists, and intensivists. Surprisingly, no randomized, placebo-controlled studies exist that show that the treatment of perioperative hypertension reduces morbidity or mortality. Nevertheless, perioperative hypertension requires careful management. While sodium nitroprusside and nitroglycerin are commonly used to treat these conditions, these agents are less than ideal. Intravenous beta blockers and calcium channel blockers have particular appeal in this setting.

Tackling agitated delirium--the tip of the iceberg

Reade et al. studied 20 agitated intubated patients in a pilot open-label trial comparing the efficacy of dexmedetomidine versus haloperidol in facilitating extubation. While the study design had limitations, which are outlined by the authors themselves in the paper published in this issue of Critical Care, the study demonstrated an impressive reduction in time to extubation and length of stay. Dexmedetomidine is a promising sedative agent that acts via α₂-receptors and has been shown to decrease prevalence and duration of delirium in mechanically ventilated patients. Haloperidol is the recommended and standard drug to treat delirium, largely based on large case series and reports. Delirium is a common, underdiagnosed and serious problem in intensive care unit patients. Agitated delirious patients are at risk of immediate adverse events as well as prolonged respiratory support. All delirious patients are at risk of poor cognitive outcomes. Further research is needed into the pharmacological management of delirium, including the use of dexmedetomidine in the management of agitation and the clinical efficacy of haloperidol.

The use of dexmedetomidine in critically ill children

OBJECTIVE

To describe the use of dexmedetomidine for sedating intubated children in a general medical/surgical pediatric intensive care unit (PICU).

DESIGN

Retrospective, observational study.

SETTING

Multidisciplinary PICU of a tertiary, university-affiliated children's hospital.

PATIENTS

All children receiving dexmedetomidine within the PICU during the period of August 2003 to August 2005.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

During the study period, 121 mechanically ventilated patients, median age 36 months (range 2 months to 21 years), who received dexmedetomidine infusions. The infusion was initiated and adjusted per our PICU protocol. The average dose was 0.55 microg/kg/hr (range 0.15-0.70 microg/kg/hr) and average length of use was 25.8 hours (range 20 minutes to 60 hours). During the dexmedetomidine infusion, the mean decrease in total benzodiazepine and opiate dose as compared with the 24 hours prior was 42% and 36%, respectively. Most patients were able to reduce their benzodiazepine and opiate dose by at least 20% with the dexmedetomidine infusion (70% and 73% of patients, respectively). After discontinuing dexmedetomidine, the average change in total benzodiazepine and opiate dose as compared with the 24 hours before infusion was an increase of 14% and 1.5%, respectively. Fewer patients were able to maintain at least a 20% reduction in benzodiazepine and opiate after cessation of dexmedetomidine compared with the 24 hours before initiation (38% and 40% of patients, respectively). Hypotension and/or bradycardia requiring clinical intervention occurred in 33 of 121 (27%) patients. Discontinuation secondary to clinical concern was necessary in 12 of 121 (10%) patients.

CONCLUSIONS

Our study suggests that many, although not all, mechanically ventilated children may be able to reduce their need for other sedation medications with the use of dexmedetomidine. However, the potential side effects of dexmedetomidine necessitates close hemodynamic monitoring with its use.

Dexmedetomidine: sedation, analgesia and beyond

BACKGROUND

Dexmedetomidine is an alpha-2 adrenoreceptor agonist with sedative, analgesic and anxiolytic properties. Since its release in the US market in late 1999, it has gained remarkable attention in the adult, pediatric and geriatric populations, predominantly because of its minimal respiratory depression. However, beyond its well-known properties, dexmedetomidine has recently been investigated for its potential in many other clinical scenarios, including neuroprotection, cardioprotection and renoprotection, with promising results.

OBJECTIVE

This review provides an outline of the current use of dexmedetomidine in adult and pediatric populations in several clinical settings, including operating room, intensive care unit, postsurgical patients and patients who need sedation and/or analgesia for invasive and noninvasive procedures. Our objectives were to examine the most up-to-date clinical evidence, describe the magnitude of effects, and shed some light on potential future applications.

METHODS

Published, peer-reviewed studies, including preclinical data, were included in this review article.

RESULTS/CONCLUSIONS

Dexmedetomidine is a novel agent with a wide safety margin and excellent sedative and moderate analgesic properties. Though its broadest use is currently in surgical and nonsurgical intensive care unit patients, dexmedetomidine appears to have promising future applications in the areas of neuroprotection, cardioprotection and renoprotection.

Dexmedetomidine infusion as adjunctive therapy to benzodiazepines for acute alcohol withdrawal

OBJECTIVE

To report a case of alcohol withdrawal and delirium tremens successfully treated with adjunctive dexmedetomidine.

CASE SUMMARY

A 30-year-old man with a history of alcohol abuse was admitted to the general medical unit because of altered mental status and agitation. He was initially treated for alcohol withdrawal with benzodiazepines; his condition then deteriorated and he was transferred to the intensive care unit. Because of the patient's poor response to benzodiazepines (oxazepam and lorazepam, with midazolam the last one used), intravenous dexmedetomidine was started at an initial dose of 0.2 microg/kg/h and titrated to 0.7 microg/kg/h to the patient's comfort. Midazolam was subsequently tapered to discontinuation due to excessive sedation. In the intensive care unit, the patient's symptoms remained controlled with use of dexmedetomidine alone. He remained in the intensive care unit for 40 hours; dexmedetomidine was then tapered to discontinuation and the patient was transferred back to the general medical unit on oral oxazepam and thiamine, which had been started in the emergency department. He was discharged after 5 days.

DISCUSSION

A review of the PubMed database (1989-2007) failed to identify any other instances of dexmedetomidine having been used as the principal agent to treat alcohol withdrawal. The use of sedative to treat delirium tremens is well documented, with benzodiazepines being the agents of choice. The clinical utility of benzodiazepines is limited by their stimulation of the gamma-aminobutyric acid receptors, an effect not shared by dexmedetomidine, a central alpha(2)-receptor agonist that induces a state of cooperative sedation and does not suppress respiratory drive.

CONCLUSIONS

In patients with delirium tremens, dexmedetomidine should be considered as an option for primary treatment. This case illustrates the need for further studies to investigate other potential uses for dexmedetomidine.