Safety and Effectiveness of Dexmedetomidine in the Pediatric Intensive Care Unit (SAD-PICU)

Clinical adverse events to dexmedetomidine: a real-world drug safety study based on the FAERS database

Objective

Adverse events associated with dexmedetomidine were analyzed using data from the FDA's FAERS database, spanning from 2004 to the third quarter of 2023. This analysis serves as a foundation for monitoring dexmedetomidine's safety in clinical applications.

Methods

Data on adverse events associated with dexmedetomidine were standardized and analyzed to identify clinical adverse events closely linked to its use. This analysis employed various signal quantification analysis algorithms, including Reporting Odds Ratio (ROR), Proportional Reporting Ratio (PRR), Bayesian Confidence Propagation Neural Network (BCPNN), and Multi-Item Gamma Poisson Shrinker (MGPS).

Results

In the FAERS database, dexmedetomidine was identified as the primary suspect in 1,910 adverse events. Our analysis encompassed 26 organ system levels, from which we selected 346 relevant Preferred Terms (PTs) for further examination. Notably, adverse drug reactions such as diabetes insipidus, abnormal transcranial electrical motor evoked potential monitoring, acute motor axonal neuropathy, and trigeminal cardiac reflex were identified. These reactions are not explicitly mentioned in the drug's specification, indicating the emergence of new signals for adverse drug reactions.

Conclusion

Data mining in the FAERS database has elucidated the characteristics of dexmedetomidine-related adverse drug reactions. This analysis enhances our understanding of dexmedetomidine's drug safety, aids in the clinical management of pharmacovigilance studies, and offers valuable insights for refining drug-use protocols.

Adverse cardiovascular events are common during dexmedetomidine administration in neonates and infants during intensive care

AIM

This study aimed to assess the safety of a commonly used sedative, dexmedetomidine in neonates and infants during intensive care.

METHODS

A retrospective cohort study was conducted in the paediatric intensive care unit at Oulu University Hospital. The study population consisted of all children from birth up to 6 months of age who received dexmedetomidine during 2010-2016. Adverse cardiovascular outcomes were defined as abnormal heart rates or blood pressure values according to the Paediatric Early Warning Score.

RESULTS

Of the 172 infants, 56% had congenital malformation, and 48% had undergone surgery. Neonates and 1-3-month-olds experienced bradycardia (86% vs. 73% in 1-3-month-olds and 50% in 3-6-month-olds, p = 0.001) and severe bradycardia (17% vs. 14% in 1-3-month-olds and 0% in 3-6-month-olds, p = 0.005) more often than older patients. The median maximum rate of dexmedetomidine infusion was 0.86 μg/kg/h (IQR = 0.60-1.71 μg/kg/h). A dose-dependent increase in bradycardia and severe hypotension was found. Adverse cardiovascular events were managed with additional fluid boluses and discontinuation of the infusion.

CONCLUSION

Adverse cardiovascular events were common during dexmedetomidine administration in neonates and infants. Lower dexmedetomidine doses may be required in sedating neonates.

A comparison of the outcomes of dexmedetomidine and remifentanil with sufentanil-based general anesthesia in pediatric patients for the transthoracic device closure of ventricular septal defects

Objective

To compare the safety and efficacy of dexmedetomidine and remifentanil with sufentanil-based general anesthesia for the transthoracic device closure of ventricular septal defects (VSDs) in pediatric patients.

Methods

A retrospective analysis was performed on 60 children undergoing the transthoracic device closure of VSDs from January 2019 to June 2020. The patients were divided into two groups based on different anesthesia strategies, including 30 cases in group R (dexmedetomidine- and remifentanil-based general anesthesia) and 30 cases in group S (sufentanil-based general anesthesia).

Results

There was no significant difference in preoperative clinical information, hemodynamics before induction and after extubation, postoperative pain scores, or length of hospital stay between the two groups. However, the hemodynamic data of group R were significantly lower than those of group S at the time points of anesthesia induction, skin incision, thoracotomy, incision closure, and extubation. The amount of intravenous patient-controlled analgesia (PCA), the duration of mechanical ventilation, and the length of the intensive care unit (ICU) stay in group R were significantly less than those in group S.

Conclusion

Dexmedetomidine combined with remifentanil-based general anesthesia for the transthoracic device closure of VSDs in pediatric patients is safe and effective.

Prevention of Withdrawal in Pediatric Patients Receiving Long-term Dexmedetomidine Infusions

OBJECTIVE

Determine if the addition of clonidine was associated with a decreased incidence of dexmedetomidine withdrawal in patients who received prolonged dexmedetomidine infusions.

METHODS

This was a retrospective observational cohort study conducted at a single-center PICU in an academic children's hospital. Children 1 month to 18 years of age who received dexmedetomidine infusion for 5 days or longer were included in the study.

RESULTS

Fifty patients met the inclusion criteria with 15 patients who received clonidine and 35 who received a dexmedetomidine wean alone. Withdrawal criteria included blood pressure changes, heart rate changes, and documented agitation. Overall, there was no difference in change in blood pressure or documented agitation between groups. Patients who did not receive clonidine had a greater number of heart rate readings above normal for age following discontinuation of the infusion, yet this was not statistically significant. Potentially more importantly, the addition of clonidine did not impact the duration of dexmedetomidine wean or the PICU length of stay after dexmedetomidine discontinuation.

CONCLUSIONS

The addition of clonidine while weaning a long-term dexmedetomidine infusion did not lead to lower blood pressures or agitation, but did lead to decreased percentage of heart rates above the age-appropriate range. The clinical significance of this is unknown, and further investigation is warranted. The addition of clonidine did not decrease time to weaning off dexmedetomidine or shorten PICU length of stay.

Effects of a Clonidine Taper on Dexmedetomidine Use and Withdrawal in Adult Critically Ill Patients-A Pilot Study

OBJECTIVES

Prolonged use of dexmedetomidine has become increasingly common due to its favorable sedative and anxiolytic properties. Hypersympathetic withdrawal symptoms have been reported with abrupt discontinuation of prolonged dexmedetomidine infusions. Clonidine has been used to transition patients off dexmedetomidine infusions for ICU sedation. The objective of this study was to compare the occurrence of dexmedetomidine withdrawal symptoms in ICU patients transitioning to a clonidine taper versus those weaned off dexmedetomidine alone after prolonged dexmedetomidine infusion.

DESIGN

This was a single-center, prospective, double cohort observational study conducted from November 2017 to December 2018.

SETTING

Medical-surgical, cardiothoracic, and neurosurgical ICUs in a tertiary care hospital.

PATIENTS

We included adult ICU patients being weaned off dexmedetomidine after receiving continuous infusions for at least 3 days.

INTERVENTIONS

Patients were either weaned off dexmedetomidine alone or with a clonidine taper at the discretion of the providers.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was the incidence of at least two dexmedetomidine withdrawal symptoms during a single assessment within 24 hours of dexmedetomidine discontinuation. Time on dexmedetomidine after wean initiation and difference in medication cost were also evaluated. Forty-two patients were included in this study: 15 received clonidine (Group C) and 27 weaned off dexmedetomidine alone (Group D). There was no significant difference in the incidence of two or more withdrawal symptoms between groups (73% in Group C vs 59% in Group D; p = 0.51). Patients in Group C spent less time on dexmedetomidine after wean initiation compared with patients in Group D (19 vs 42 hr; p = 0.02). An average cost savings of $1,553.47 per patient who received clonidine was observed. No adverse effects were noted.

CONCLUSIONS

Our study demonstrated that patients receiving clonidine were able to wean off dexmedetomidine more rapidly, with a considerable cost savings and no difference in dexmedetomidine withdrawal symptoms, compared with patients weaned off dexmedetomidine alone. Clonidine may be a safe, effective, and practical option to transition patients off prolonged dexmedetomidine infusions.

Evaluating the Transition From Dexmedetomidine to Clonidine for the Prevention of Withdrawal in Critically Ill Pediatric Patients

OBJECTIVES

To evaluate clonidine for preventing withdrawal from dexmedetomidine infusions and describe the incidence of withdrawal symptoms and adverse cardiovascular effects in critically ill pediatric patients.

METHODS

Retrospective, descriptive study of patients in Advocate Children's Hospital-Park Ridge PICU who received dexmedetomidine infusion for ≥72 hours, followed by clonidine for ≥48 hours, between January 1, 2015, and August 31, 2017.

RESULTS

Thirty-eight patients (median age 4.3 years; IQR, 2-11.5) received 39 dexmedetomidine courses. The median duration of dexmedetomidine exposure was 7.6 days (IQR, 5-11.5) at an average dose of 1 mcg/kg/hr. The median dose of clonidine at initiation was 8.3 mcg/kg/day (for <50 kg) and 4.1 mcg/kg/day (for ≥50 kg). The most common oral administration frequency was every 8 hours. Dexmedetomidine infusions for 7 days or longer and a higher dexmedetomidine dose 24 hours prior to clonidine transition both correlated with increased initial clonidine doses. Fourteen patients (37%) had at least 1 WAT-1 score of ≥3 during the transition between dexmedetomidine and clonidine, with 7 (18%) requiring an increase in sedation. Adverse cardiovascular events were possibly attributable to dexmedetomidine and/or clonidine in 4 patients.

CONCLUSIONS

Patients receiving prolonged infusions of dexmedetomidine may transition to clonidine to help prevent withdrawal symptoms. Duration of dexmedetomidine infusion of 7 days or longer and higher average dexmedetomidine dose 24 hours prior to the transition are important considerations when determining the initial clonidine dose. Transition from dexmedetomidine to clonidine was found to be safe and efficacious in our patients, with minimal adverse effects.

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.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Prolonged dexmedetomidine infusion in critically ill adult patients: a retrospective analysis of a large clinical database Multiparameter Intelligent Monitoring in Intensive Care III

Background

There is no conclusive evidence for the effects of prolonged infusion of dexmedetomidine in critically ill patients. We aimed to investigate the safety of long-term dexmedetomidine infusion in a large critically ill patients cohort from the Multiparameter Intelligent Monitoring in Intensive Care III (MIMIC-III) database.

Methods

We retrospectively extracted records from MIMIC-III database. Dexmedetomidine administration time was the basis for group. Variables were compared by chi-square tests, and Mann-Whitney U test as appropriate. We used logistic regression model for multivariate analysis. Contour maps were drawn to measure rebound of heart rate (HR) and blood pressure (BP).

Results

We finally got 1,946 records including 1,368 distinct individuals. Age, body mass index (BMI), length of stay in hospital, accumulated doses of dexmedetomidine and Sequential Organ Failure Assessment (SOFA) score were independent risk factors of in-hospital mortality (P<0.05). But prolonged dexmedetomidine infusion (≥24 h) and abrupt cessation did not increase in-hospital mortality. Furthermore, the rebound of HR and BP was more likely to occur in patients with prolonged infusion of dexmedetomidine.

Conclusions

Prolonged dexmedetomidine infusion is not related to an increased in-hospital mortality, but it is associated with the rebound effect of HR and BP. Further prospective studies are needed.

Prolonged Dexmedetomidine Infusion and Drug Withdrawal In Critically Ill Children

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Dexmedetomidine 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.

Clinical recommendations for pain, sedation, withdrawal and delirium assessment in critically ill infants and children: an ESPNIC position statement for healthcare professionals

Background

This position statement provides clinical recommendations for the assessment of pain, level of sedation, iatrogenic withdrawal syndrome and delirium in critically ill infants and children. Admission to a neonatal or paediatric intensive care unit (NICU, PICU) exposes a child to a series of painful and stressful events. Accurate assessment of the presence of pain and non-pain-related distress (adequacy of sedation, iatrogenic withdrawal syndrome and delirium) is essential to good clinical management and to monitoring the effectiveness of interventions to relieve or prevent pain and distress in the individual patient.

Methods

A multidisciplinary group of experts was recruited from the members of the European Society of Paediatric and Neonatal Intensive Care (ESPNIC). The group formulated clinical questions regarding assessment of pain and non-pain-related distress in critically ill and nonverbal children, and searched the PubMed/Medline, CINAHL and Embase databases for studies describing the psychometric properties of assessment instruments. Furthermore, level of evidence of selected studies was assigned and recommendations were formulated, and grade or recommendations were added on the basis of the level of evidence.

Results

An ESPNIC position statement was drafted which provides clinical recommendations on assessment of pain (n = 5), distress and/or level of sedation (n = 4), iatrogenic withdrawal syndrome (n = 3) and delirium (n = 3). These recommendations were based on the available evidence and consensus amongst the experts and other members of ESPNIC.

Conclusions

This multidisciplinary ESPNIC position statement guides professionals in the assessment and reassessment of the effectiveness of treatment interventions for pain, distress, inadequate sedation, withdrawal syndrome and delirium.

Electronic supplementary material

The online version of this article (doi:10.1007/s00134-016-4344-1) contains supplementary material, which is available to authorized users.

Pain and Sedation Management in Mechanically Ventilated Children

Assessing and managing pain and agitation in critically ill children can be challenging. Multiple factors contribute to the challenges of management, including prior medication exposure, surgical and procedural interventions, pharmacokinetics, and age-related pharmacodynamics making the population heterogeneous. Therefore, individualizing treatment approaches embedded with frequent assessments is likely to improve the management of pain and agitation in critically ill children. Novel approaches to manage pain and agitation continue to evolve and will require ongoing evaluation prior to widespread adoption.

Dexmedetomidine for Sedation during Withdrawal of Support

Agents used to control end-of-life suffering are associated with troublesome side effects. The use of dexmedetomidine for sedation during withdrawal of support in pediatrics is not yet described. An adolescent female with progressive and irreversible pulmonary deterioration was admitted. Despite weeks of therapy, she did not tolerate weaning of supplemental oxygen or continuous bilevel positive airway pressure. Given her condition and the perception that she was suffering, the family requested withdrawal of support. Despite opioids and benzodiazepines, she appeared to be uncomfortable after support was withdrawn. Ketamine was initiated. Relief from ketamine was brief, and its use was associated with a "wide-eyed" look that was distressing to the family. Ketamine was discontinued and a dexmedetomidine infusion was initiated. The patient's level of comfort improved greatly. The child died peacefully 24 hours after initiating dexmedetomidine from her underlying disease rather than the effects of the sedative.

Alpha-2 agonists for long-term sedation during mechanical ventilation in critically ill patients

BACKGROUND

Sedation reduces patient levels of anxiety and stress, facilitates the delivery of care and ensures safety. Alpha-2 agonists have a range of effects including sedation, analgesia and antianxiety. They sedate, but allow staff to interact with patients and do not suppress respiration. They are attractive alternatives for long-term sedation during mechanical ventilation in critically ill patients.

OBJECTIVES

To assess the safety and efficacy of alpha-2 agonists for sedation of more than 24 hours, compared with traditional sedatives, in mechanically-ventilated critically ill patients.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, Issue 10, 2014), MEDLINE (1946 to 9 October 2014), EMBASE (1980 to 9 October 2014), CINAHL (1982 to 9 October 2014), Latin American and Caribbean Health Sciences Literature (1982 to 9 October 2014), ISI Web of Science (1987 to 9 October 2014), Chinese Biological Medical Database (1978 to 9 October 2014) and China National Knowledge Infrastructure (1979 to 9 October 2014), the World Health Organization international clinical trials registry platform (to 9 October 2014), Current Controlled Trials metaRegister of controlled trials active registers (to 9 October 2014), the ClinicalTrials.gov database (to 9 October 2014), the conference proceedings citation index (to 9 October 2014) and the reference lists of included studies and previously published meta-analyses and systematic reviews for relevant studies. We imposed no language restriction.

SELECTION CRITERIA

We included all randomized and quasi-randomized controlled trials comparing alpha-2 agonists (clonidine or dexmedetomidine) versus alternative sedatives for long-term sedation (more than 24 hours) during mechanical ventilation in critically ill patients.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study quality and extracted data. We contacted study authors for additional information. We performed meta-analyses when more than three studies were included, and selected a random-effects model due to expected clinical heterogeneity. We calculated the geometric mean difference for continuous outcomes and the risk ratio for dichotomous outcomes. We described the effects by values and 95% confidence intervals (CIs). We considered two-sided P < 0.05 to be statistically significant.

MAIN RESULTS

Seven studies, covering 1624 participants, met the inclusion criteria. All included studies investigated adults and compared dexmedetomidine with traditional sedatives, including propofol, midazolam and lorazepam. Compared with traditional sedatives, dexmedetomidine reduced the geometric mean duration of mechanical ventilation by 22% (95% CI 10% to 33%; four studies, 1120 participants, low quality evidence), and consequently the length of stay in the intensive care unit (ICU) by 14% (95% CI 1% to 24%; five studies, 1223 participants, very low quality evidence). There was no evidence that dexmedetomidine decreased the risk of delirium (RR 0.85; 95% CI 0.63 to 1.14; seven studies, 1624 participants, very low quality evidence) as results were consistent with both no effect and appreciable benefit. Only one study assessed the risk of coma, but lacked methodological reliability (RR 0.69; 95% CI 0.55 to 0.86, very low quality evidence). Of all the adverse events included, the most commonly reported one was bradycardia, and we observed a doubled (111%) increase in the incidence of bradycardia (RR 2.11; 95% CI 1.39 to 3.20; six studies, 1587 participants, very low quality evidence). Our meta-analysis provided no evidence that dexmedetomidine had any impact on mortality (RR 0.99; 95% CI 0.79 to 1.24; six studies, 1584 participants, very low quality evidence). We observed high levels of heterogeneity in risk of delirium (I² = 70%), but due to the limited number of studies we were unable to determine the source of heterogeneity through subgroup analyses or meta-regression. We judged six of the seven studies to be at high risk of bias.

AUTHORS' CONCLUSIONS

In this review, we found no eligible studies for children or for clonidine. Compared with traditional sedatives, long-term sedation using dexmedetomidine in critically ill adults reduced the duration of mechanical ventilation and ICU length of stay. There was no evidence for a beneficial effect on risk of delirium and the heterogeneity was high. The evidence for risk of coma was inadequate. The most common adverse event was bradycardia. No evidence indicated that dexmedetomidine changed mortality. The general quality of evidence ranged from very low to low, due to high risks of bias, serious inconsistency and imprecision, and strongly suspected publication bias. Future studies could pay more attention to children and to using clonidine