The use of dexmedetomidine in critically ill children

Acute Pain Management Protocols in Pediatric Intensive Care Units

Pediatric pain has historically been difficult to assess and even more difficult to treat. It is encouraging that there is current research regarding pain control in pediatric patients that provide evidence for treating pediatric pain. Patients in a pediatric intensive care setting demonstrate a great deal of patient variability with regard to patient diagnosis, age, developmental level, weight, and amount of pain control needed. The use of an evidence-based protocol for pediatric pain control can decrease variability in pain control and decrease potential adverse effects such as respiratory depression, constipation, withdrawal, delirium, and developmental delays while allowing for patient variability.

Perioperative dexmedetomidine compared to midazolam in children undergoing open-heart surgery: A pilot randomised controlled trial

Objective

There is a need for evidence on the best sedative agents in children undergoing open heart surgery for congenital heart disease. This study aimed to evaluate the feasibility and safety of dexmedetomidine in this group compared with midazolam.

Design

Double blinded, pilot randomized controlled trial.

Setting

Cardiac operating theatre and paediatric intensive care unit in Brisbane, Australia.

Participants

Infants (≤12 months of age) undergoing their first surgical repair of a congenital heart defect.

Interventions

Dexmedetomidine (up to 1.0mcg/kg/hr) versus midazolam (up to 80mcg/kg/hr), commenced in the cardiac operating theatre prior to surgery.

Main outcome measures

The primary outcome was the time spent in light sedation (Sedation Behavior Scale [SBS] -1 to +1); Co-primary feasibility outcome was recruitment, retention and protocol adherence. Secondary outcomes were use of supplemental sedatives, ventilator free days, delirium, vasoactive drug support, and adverse events. Neurodevelopment and health-related quality of life (HRQoL) were assessed at 12 months post-surgery.

Results

Sixty-six participants were recruited. The number of SBS scores in the light sedation range were greater in the dexmedetomidine group at 24 hours, 48 hours, and overall study duration (0-14 days) versus the midazolam group (24hr: 76/170 [45%] vs 60/178 [34%], aOR 4.14 [95% CI 0.48, 35.92]; 48hr: 154/298 [52%] vs 122/314 [39%], aOR 6.95 [95% CI 0.77, 63.13]; 0-14 days: 597/831 [72%] vs 527/939 [56%], aOR 3.93 [95% CI 0.62, 25.03]). Feasibility was established with no withdrawals or loss to follow-up at 14 days and minimal protocol deviations. There were no differences between the groups relating to clinical, safety, neurodevelopment or HRQoL outcomes.

Conclusions

The use of dexmedetomidine was associated with more time spent in light sedation when compared with midazolam. The feasibility of conducting a blinded RCT of midazolam and dexmedetomidine in children undergoing open heart surgery was also established. The findings justify further investigation in a larger trial.

Clinical trial registration

ACTRN12615001304527.

Recommendations for analgesia and sedation in critically ill children admitted to intensive care unit

We aim to develop evidence-based recommendations for intensivists caring for children admitted to intensive care units and requiring analgesia and sedation. A panel of national paediatric intensivists expert in the field of analgesia and sedation and other specialists (a paediatrician, a neuropsychiatrist, a psychologist, a neurologist, a pharmacologist, an anaesthesiologist, two critical care nurses, a methodologist) started in 2018, a 2-year process. Three meetings and one electronic-based discussion were dedicated to the development of the recommendations (presentation of the project, selection of research questions, overview of text related to the research questions, discussion of recommendations). A telematic anonymous consultation was adopted to reach the final agreement on recommendations. A formal conflict-of-interest declaration was obtained from all the authors. Eight areas of direct interest and one additional topic were considered to identify the best available evidence and to develop the recommendations using the Evidence-to-Decision framework according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. For each recommendation, the level of evidence, the strength of the recommendation, the benefits, the harms and the risks, the benefit/harm balance, the intentional vagueness, the values judgement, the exclusions, the difference of the opinions, the knowledge gaps, and the research opportunities were reported. The panel produced 17 recommendations. Nine were evaluated as strong, 3 as moderate, and 5 as weak. Conclusion: a panel of national experts achieved consensus regarding recommendations for the best care in terms of analgesia and sedation in critically ill children.

Long-Term Increases in Mental Disorder Diagnoses After Invasive Mechanical Ventilation for Severe Childhood Respiratory Disease: A Propensity Matched Observational Cohort Study

OBJECTIVES

To evaluate neurodevelopmental and mental disorders after PICU hospitalization in children requiring invasive mechanical ventilation for severe respiratory illness.

DESIGN

Retrospective longitudinal observational cohort.

SETTING

Texas Medicaid Analytic eXtract data from 1999 to 2012.

PATIENTS

Texas Medicaid-enrolled children greater than or equal to 28 days old to less than 18 years old hospitalized for a primary respiratory illness, without major chronic conditions predictive of abnormal neurodevelopment.

INTERVENTIONS

We examined rates of International Classification of Diseases, 9th revision-coded mental disorder diagnoses and psychotropic medication use following discharge among children requiring invasive mechanical ventilation for severe respiratory illness, compared with general hospital patients propensity score matched on sociodemographic and clinical characteristics prior to admission. Children admitted to the PICU for respiratory illness not necessitating invasive mechanical ventilation were also compared with matched general hospital patients as a negative control exposure.

MEASUREMENTS AND MAIN RESULTS

Of 115,335 eligible children, 1,351 required invasive mechanical ventilation and were matched to 6,755 general hospital patients. Compared with general hospital patients, children requiring invasive mechanical ventilation had increased mental disorder diagnoses (hazard ratio, 1.43 [95% CI, 1.26-1.64]; p < 0.0001) and psychotropic medication use (hazard ratio, 1.67 [1.34-2.08]; p < 0.0001) following discharge. Seven-thousand seven-hundred eighty children admitted to the PICU without invasive mechanical ventilation were matched to 38,900 general hospital patients and had increased mental disorder diagnoses (hazard ratio, 1.08 [1.02-1.15]; p = 0.01) and psychotropic medication use (hazard ratio, 1.11 [1.00-1.22]; p = 0.049).

CONCLUSIONS

Children without major comorbidity requiring invasive mechanical ventilation for severe respiratory illness had a 43% higher incidence of subsequent mental disorder diagnoses and a 67% higher incidence of psychotropic medication use. Both increases were substantially higher than in PICU patients with respiratory illness not necessitating invasive mechanical ventilation. Invasive mechanical ventilation is a life-saving therapy, and its application is interwoven with underlying health, illness severity, and PICU management decisions. Further research is required to determine which factors related to invasive mechanical ventilation and severe respiratory illness are associated with abnormal neurodevelopment. Given the increased risk in these children, identification of strategies for prevention, neurodevelopmental surveillance, and intervention after discharge may be warranted.

Age-Specific Dose Regimens of Dexmedetomidine for Pediatric Patients in Intensive Care Following Elective Surgery: A Phase 3, Multicenter, Open-Label Clinical Trial in Japan

OBJECTIVES

To demonstrate the efficacy, safety, and pharmacokinetics of dexmedetomidine as a potential sedative for pediatric surgery patients in the ICU.

DESIGN

Phase 3, multicenter, open-label study.

SETTING

This study included 61 patients at 13 tertiary hospitals in Japan.

PATIENTS

Pediatric patients (≥ 45 wk corrected gestational age to < 17 yr) undergoing intensive care treatment with mechanical ventilation requiring greater than 6 hours estimated duration of sedation following elective cardiac surgery.

INTERVENTIONS

Dexmedetomidine was IV administered without a loading dose at age-specific dose regimens 0.2-1.4 (< 6 yr) and 0.2-1.0 µg/kg/hr (≥ 6 yr). The primary endpoint was the percentage of patients who did not require a rescue sedative (midazolam) infusion during mechanical ventilation or for the first 24 hours of a greater than 24 hours ventilation following the commencement of dexmedetomidine administration.

MEASUREMENTS AND MAIN RESULTS

Overall, 47 of the 61 patients (77.0%) did not require rescue midazolam. Adverse events were reported in 53 patients (86.9%). Frequently observed adverse events were hypotension (47.5%), bradycardia (31.1%), and respiratory depression (26.2%). Most of these adverse events were mild, a few moderate, and none severe. Although serious adverse events occurred in four patients, including one cardiac tamponade resulting in the withdrawal of dexmedetomidine, none of the adverse events resulted in mortality or were directly related to dexmedetomidine. The plasma dexmedetomidine concentration generally reached the target concentration of 0.3-1.25 ng/mL at 1-2 hours prior to completion of administration or immediately prior to the commencement of tapering.

CONCLUSIONS

The age-specific dose regimens of dexmedetomidine without an initial loading dose achieved an adequate sedation level during mechanical ventilation and caused no clinically significant adverse events in the intensive care pediatric patients. These effects were achieved within the therapeutic range of dexmedetomidine plasma concentration and were accompanied by minimal effects on hemodynamics and respiration.

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.

Dexmedetomidine and Iatrogenic Withdrawal Syndrome in Critically Ill Children

BACKGROUND

Iatrogenic withdrawal syndrome is a well-known adverse effect of sedatives and analgesics commonly used in patients receiving mechanical ventilation in the pediatric intensive care unit, with an incidence of up to 64.6%. When standard sedative and analgesic treatment is inadequate, dexmedetomidine may be added. The effect of supplemental dexmedetomidine on iatrogenic withdrawal syndrome is unclear.

OBJECTIVE

To explore the potentially preventive effect of dexmedetomidine, used as a supplement to standard morphine and midazolam regimens, on the development of iatrogenic withdrawal syndrome in patients receiving mechanical ventilation in the pediatric intensive care unit.

METHODS

This retrospective observational study used data from patients on a 10-bed general pediatric intensive care unit. Iatrogenic withdrawal syndrome was measured using the Sophia Observation withdrawal Symptoms-scale.

RESULTS

In a sample of 102 patients, the cumulative dose of dexmedetomidine had no preventive effect on the development of iatrogenic withdrawal syndrome (P = .19). After correction for the imbalance in the baseline characteristics between patients who did and did not receive dexmedetomidine, the cumulative dose of midazolam was found to be a significant risk factor for iatrogenic withdrawal syndrome (P < .03).

CONCLUSION

In this study, supplemental dexmedetomidine had no preventive effect on iatrogenic withdrawal syndrome in patients receiving sedative treatment in the pediatric intensive care unit. The cumulative dose of midazolam was a significant risk factor for iatrogenic withdrawal syndrome.

Dexmedetomidine Sedation in Mechanically Ventilated Critically Ill Children: A Pilot Randomized Controlled Trial

OBJECTIVES

To assess the feasibility, safety, and efficacy of a sedation protocol using dexmedetomidine as the primary sedative in mechanically ventilated critically ill children.

DESIGN

Open-label, pilot, prospective, multicenter, randomized, controlled trial. The primary outcome was the proportion of sedation scores in the target sedation range in the first 48 hours. Safety outcomes included device removal, adverse events, and vasopressor use. Feasibility outcomes included time to randomization and protocol fidelity.

SETTING

Six tertiary PICUs in Australia and New Zealand.

PATIENTS

Critically ill children, younger than 16 years old, requiring intubation and mechanical ventilation and expected to be mechanically ventilated for at least 24 hours.

INTERVENTIONS

Children randomized to dexmedetomidine received a dexmedetomidine-based algorithm targeted to light sedation (State Behavioral Scale -1 to +1). Children randomized to usual care received sedation as determined by the treating clinician (but not dexmedetomidine), also targeted to light sedation.

MEASUREMENTS AND MAIN RESULTS

Sedation with dexmedetomidine as the primary sedative resulted in a greater proportion of sedation measurements in the light sedation range (State Behavioral Scale -1 to +1) over the first 48 hours (229/325 [71%] vs 181/331 [58%]; p = 0.04) and the first 24 hours (66/103 [64%] vs 48/116 [41%]; p < 0.001) compared with usual care. Cumulative midazolam dosage was significantly reduced in the dexmedetomidine arm compared with usual care (p = 0.002).There were more episodes of hypotension and bradycardia with dexmedetomidine (including one serious adverse event) but no difference in vasopressor requirements. Median time to randomization after intubation was 6.0 hours (interquartile range, 2.0-9.0 hr) in the dexmedetomidine arm compared with 3.0 hours (interquartile range, 1.0-7.0 hr) in the usual care arm (p = 0.24).

CONCLUSIONS

A sedation protocol using dexmedetomidine as the primary sedative was feasible, appeared safe, achieved early, light sedation, and reduced midazolam requirements. The findings of this pilot study justify further studies of sedative agents in critically ill children.

A nurse-driven analgesia and sedation protocol reduces length of PICU stay and cumulative dose of benzodiazepines after corrective surgery for tetralogy of Fallot

PURPOSE

Analgesia and sedation protocols are reported to reduce the requirement of sedative and analgesic agents, duration of mechanical ventilation, and length of pediatric intensive care unit (PICU) stay. However, these studies often were conducted based on inhomogeneous cohorts. The aim of this study was the evaluation of a nurse-driven analgesia and sedation protocol in a homogenous population of infants following corrective surgery for tetralogy of Fallot (TOF).

DESIGN AND METHODS

This retrospective analysis was conducted in a cardiac PICU of a tertiary referral center. Two cohorts of patients who underwent corrective surgery for TOF below the age of 7 months, were retrospectively evaluated before and after implementation of a nurse-driven analgesia and sedation protocol. We compared peak and cumulative doses of midazolam, morphine, and clonidine, length of PICU stay and time on mechanical ventilation.

RESULTS

A total of 33 patients were included in the preimplementation period and 32 during the postimplementation period. Implementation of the nurse-driven analgesia and sedation protocol had no effect on time on mechanical ventilation (72 hr [24-141] vs. 49 hr [24-98]), but significantly on length of PICU stay (7 days [5-14] vs. 5 days [4-7]). Cumulative doses of midazolam (7.37 mg/kg [4.70-17.65] vs. 5.0 mg/kg [2.70-9.12]) as well as peak doses of midazolam (0.22 mg·kg^-1 ·hr^-1 [0.20-0.33] vs. 0.15 mg·kg^-1 ·hr^-1 [0.13-0.20]) and morphine (50.0 µg·kg^-1 ·hr^-1 [39.7-79.9] vs. 42.5 µg·kg^-1 ·hr^-1 [29.7-51.8]) were significantly reduced. The postimplemantation group showed no increase in postoperative complications and adverse events.

PRACTICE IMPLICATIONS

The implementation of a nurse-driven analgesia and sedation protocol is safe in infants following corrective surgery for TOF. It reduces significantly the length of PICU stay, cumulative and peak doses of midazolam and peak doses of morphine.

The impact of a quality improvement project to standardize pain, agitation, and withdrawal assessments on the use of morphine and midazolam in the Pediatric Intensive Care Unit

BACKGROUND

This study aims to assess the impact of a quality improvement initiative to increase assessments of pain, agitation, and iatrogenic withdrawal syndrome, on the use of sedative and analgesic medication in a pediatric intensive care unit.

METHODS

This is a retrospective pre and post, observational, quality improvement study conducted in an 18-bed medical-surgical-cardiac, tertiary intensive care unit. We included patients consecutively admitted from October 1 to March 31 (pre-period 2015-2016, post-period 2016-2017) who were mechanically ventilated beyond 48 hours. A multidisciplinary team, including a family advisor, implemented the following interventions using rapid "Plan-Do-Study-Act cycles:" (a) standardized pain and sedation assessments, (b) standardized sedation goal setting, and (c) non-pharmacological strategies to manage pain and agitation. We did not implement any specific sedation protocol. We used audit and feedback to reinforce change.

RESULTS

The post-intervention phase started once sedation scores were documented q12h for >60% of patients. The groups (n = 45 per group) were similar regarding demographics, severity of illness, and mechanical ventilation duration, but different in length of intensive care stay. The cumulative dose of midazolam equivalent was significantly lower in the post-intervention period (3.71 vs 2.65 mg/kg/mechanical ventilation day, P = 0.009, 95% CI: -1.12 (-1.89, -0.31)). Morphine equivalent usage went from 3.51 to 2.57 mg/kg/mechanical ventilation day (P = 0.066, 95% CI: -0.67 [-1.44, 0.05]). There were no significant pre-post-differences in the use of other sedative agents, rates of iatrogenic withdrawal syndrome or severe pain, nor medication cost.

CONCLUSION

Implementation of a multifaceted QI project was successful at increasing standardized assessments of pain and agitation, and was associated with a significant reduction in midazolam use. We also observed a decrease in morphine use without increasing rates of severe pain. Incidence of iatrogenic withdrawal syndrome and cost were unchanged.

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.

Dexmedetomidine is effective and safe during NIV in infants and young children with acute respiratory failure

BACKGROUND

Noninvasive ventilation (NIV) is increasingly utilized in infants and young children, though associated with high failure rates due to agitation and poor compliance, mostly if patient-ventilator synchronization is required.

METHODS

A retrospective cohort study was carried out in an academic pediatric intensive care unit (PICU). Dexmedetomidine (DEX) was infused as unique sedative in 40 consecutive pediatric patients (median age 16 months) previously showing intolerance and agitation during NIV application.

RESULTS

During NIV clinical application both COMFORT-B Score and Richmond Agitation-Sedation Scale (RASS) were serially evaluated. Four patients experiencing NIV failure, all due to pulmonary condition worsening, required intubation and invasive ventilation. 36 patients were successfully weaned from NIV under DEX sedation and discharged from PICU. All patients survived until home discharge.

CONCLUSION

Our data suggest that DEX may represent an effective sedative agent in infants and children showing agitation during NIV. Early use of DEX in infants/children receiving NIV for acute respiratory failure (ARF) should be considered safe and capable of improving NIV, thus permitting both lung recruitment and patient-ventilator synchronization.

Application of pre-injection of dexmedetomidine of different doses in pediatric intravenous general anesthesia without tracheal intubation

This study observed the clinical efficacy of pre-injection of dexmedetomidine of different doses before surgery and the adverse reactions during the recovery period in pediatric intravenous general anesthesia without tracheal intubation. Pediatric patients who received general anesthesia without tracheal intubation before surgery from January 2016 to March 2017 were randomly divided into four groups (n=30), and were respectively treated with intravenous pump infusion of loaded dexmedetomidine of high-dose (2.5 µg/kg), middle-dose (1.5 µg/kg) and low-dose (0.5 µg/kg), while the children in the control group received injection of normal saline in same dose. Then, the mean arterial pressure (MAP) at different time points (5 and 10 min after administration, after anesthesia and after surgery), heart rate, Ramsay sedation score changes and adverse reactions during recovery period of anesthesia of pediatric patients were compared among four groups. At 5 and 10 min after administration, Ramsay scores of high-dose group and middle-dose group were higher than that of the control group, and the differences had statistical significance (P<0.05). There was no significant difference in comparison of Ramsay scores between low-dose group and the control group. The MAP and heart rate after anesthesia and after surgery of pediatric patients with pump infusion of dexmedetomidine in the three groups were decreased significantly compared to those of the control group, and the differences had statistical significance (P<0.05). The incidence rate of adverse reaction of pediatric patients during the recovery period after pump infusion in the three groups and the control group was, respectively, 13/30, 8/30, 7/30 and 8/30, and the differences were statistically significant (P<0.05). The sedative effect and safety of pre-injection of dexmedetomidine in pediatric intravenous general anesthesia without tracheal intubation are promising, and the medium dosage can maximize the anesthetic effect with less side effects.

Relationship between dexmedetomidine dose and plasma dexmedetomidine concentration in critically ill infants: a prospective observational cohort study

Background

Dexmedetomidine is a highly selective central α₂-agonist used as a sedative in pediatric intensive care unit (PICU). However, little is known about the relationship between dexmedetomidine dose and its plasma concentration during long-term infusion. We have previously demonstrated that the sedative plasma dexmedetomidine concentration is moderately correlated with the administered dose in adults (r = 0.653, P = 0.001). We hypothesized that there would be a similar relationship between the sedative dexmedetomidine concentration and administered dose in infants.

Methods

All patients admitted to the PICU at Nagoya City University Hospital, Japan, between November 2012 and March 2013 were eligible for inclusion in the study. Plasma dexmedetomidine concentration was measured by ultra-performance liquid chromatography coupled with tandem mass spectrometry.

Results

We measured the plasma dexmedetomidine concentration in 203 samples from 45 patients. Of these, 96 samples collected from 27 patients < 2 years old were included in this study. All patients received dexmedetomidine at 0.12–1.40 µg/kg/h. The median administration duration was 87.6 hours (range: 6–540 hours). Plasma dexmedetomidine concentration ranged from 0.07 to 3.17 ng/ml. Plasma dexmedetomidine concentration was not correlated with the administered dose (r = 0.273, P = 0.007). The approximate linear equation was y = 0.690x + 0.423.

Conclusions

In infants, plasma dexmedetomidine concentration did not exhibit any correlation with administered dose, which is not a reliable means of obtaining optimal plasma concentration.

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.

Intranasal Dexmedetomidine Sedation as Adjuvant Therapy in Acute Asthma Exacerbation With Marked Anxiety and Agitation

We describe 2 patients with acute asthma exacerbation who were admitted to the emergency department (ED) with severe agitation and restlessness as a prominent finding, for which bedside asthma treatment sedation with intranasal dexmedetomidine was performed. In both cases, dexmedetomidine allowed the patients to rest and improved tolerance to treatment. Dexmedetomidine is a unique sedative with an excellent safety profile and minimal effect on respiratory function. These properties render it particularly promising for the management of severe agitation in children admitted to the ED with acute asthma exacerbation.

Dexmedetomidine is Associated with an Increased Incidence of Bradycardia in Patients with Trisomy 21 After Surgery for Congenital Heart Disease

This study aimed to evaluate adverse cardiac events using dexmedetomidine in infants with trisomy 21 and those without (controls) and examined potential risk factors in infants after cardiovascular surgery. We conducted a single-center retrospective cohort study. The medical records of 124 consecutive infants who had undergone cardiovascular surgery between April 1, 2013, and October 31, 2015, were enrolled. Clinical characteristics, usage of dexmedetomidine, and perioperative medications were analyzed. Adverse cardiac events were assessed with the Naranjo score and World Health Organization-The Uppsala Monitoring Centre (WHO-UMC) criteria. In total, 124 consecutive infants (30 patients and 94 controls) met the inclusion criteria. Eight of 30 (26.7 %) patients with trisomy 21 and 12 of 94 (12.8 %) controls experienced adverse cardiac events (i.e., hypotension, transient hypertension, and bradycardia) during dexmedetomidine with median Naranjo score of 6, and causality categories of WHO-UMC criteria were "certain" or "probable." Of those, the incidence of bradycardia occurred at a higher rate in patients with trisomy 21 than in controls (P = 0.011). Multiple logistic regression analysis revealed that the presence of trisomy 21 was an independent risk factor for adverse cardiac events of dexmedetomidine after cardiovascular surgery (odds ratio 4.10, 95 % CI 1.17-11.19, P = 0.006). Dexmedetomidine is associated with an increased incidence of bradycardia in patients with trisomy 21 after surgery for congenital heart disease. Physicians using dexmedetomidine should know a great deal about the characteristics of patients with trisomy 21, and hemodynamic monitoring should be closely observed.

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 reduces cranial temperature in hypothermic neonatal rats

BACKGROUND

The α2-adrenergic agonist dexmedetomidine (DEX) is increasingly used for prolonged sedation of critically ill neonates, but there are currently no data evaluating possible consequences of prolonged neonatal DEX exposure. We evaluated the pharmacokinetics and histological consequences of neonatal DEX exposure.

METHODS

DEX was administered (s.c.) to naive (uninjured) neonatal Lewis rats to provide acute (25 µg/kg, ×1) or prolonged (25 µg/kg three times daily, ×2 or ×4 d) exposure. Therapeutic hypothermia was simulated using a water-cooled blanket. Cranial temperatures were measured using an infrared thermometer. DEX concentrations were measured by LC-MS in plasma and homogenized brainstem tissue for pharmacokinetic analysis. Cortex, cerebellum, and brainstem were evaluated for evidence of inflammation or injury.

RESULTS

Prolonged neonatal DEX exposure was not associated with renal or brain pathology or indices of gliosis, macrophage activation, or apoptosis in either hypothermic or control rats. Plasma and brain DEX concentrations were tightly correlated. DEX peaked within 15 min in brain and reduced cranial temperature from 32 to 30 °C within 30 min after injection in cooled rats.

CONCLUSION

Prolonged DEX treatment in neonatal rats was not associated with abnormal brain histology. These data provide reassuring preliminary results for using DEX with therapeutic hypothermia to treat near-term brain injury.

Effects of Clonidine on Withdrawal From Long-term Dexmedetomidine in the Pediatric Patient

OBJECTIVE

To compare withdrawal symptoms among pediatric intensive care patients receiving clonidine to those not receiving clonidine while being weaned from long-term dexmedetomidine.

METHODS

This retrospective analysis evaluated Withdrawal Assessment Tool-1 (WAT-1) scores and hemodynamic parameters in pediatric patients on dexmedetomidine for 5 days or longer between January 1, 2009, and December 31, 2012. The primary objective was to compare withdrawal symptoms based on the number of elevated WAT-1 scores among patients on clonidine to those not on clonidine, while being weaned from long-term dexmedetomidine. The secondary objective was to describe withdrawal symptoms associated with long-term dexmedetomidine use.

RESULTS

Nineteen patients (median age, 1.5 years; interquartile range [IQR], 0.67-3.3) received 20 treatment courses of dexmedetomidine for at least 5 days. Clonidine was received by patients during 12 of the treatment courses. The patients in the clonidine group had an average of 0.8 (range, 0-6) elevated WAT-1 scores 24 hours post wean compared to an average of 3.2 (0-8) elevated WAT-1 scores in the no clonidine group (p = 0.49). There were no significant difierences between prewean and postwean systolic or diastolic blood pressures among the 2 groups. The average heart rate during the postwean period was 112 beats per minute (bpm) (range, 88.5-151.5) in the clonidine group compared to 138.4 bpm (range, 117.8-168.3) in the no clonidine group (p = 0.003). In the clonidine group, the mean change in heart rate postwean compared to prewean was an increase of 3.6 bpm (range, -39.6 to 47.5), compared to a mean increase of 29.9 bpm (range, 5.5-74.7) in the no clonidine group (p = 0.042).

CONCLUSIONS

There was no difierence in WAT-1 scores between groups, with the clonidine group displaying a trend towards fewer elevated WAT-1 scores during the 24 hours post dexmedetomidine wean. Patients who received clonidine had significantly lower heart rates than the no clonidine group.

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

Retrospective Evaluation of the Epidemiology and Practice Variation of Dexmedetomidine Use in Invasively Ventilated Pediatric Intensive Care Admissions, 2007-2013

OBJECTIVES

The study assessed dexmedetomidine utilization and practice variation over time in ventilated pediatric intensive care unit (PICU) patients; and evaluated differences in hospital outcomes between high- and low-dexmedetomidine utilization hospitals.

STUDY DESIGN

This serial cross-sectional analysis used administrative data from PICU admissions in the pediatric health information system (37 US tertiary care pediatric hospitals). Included admissions from 2007 to 2013 had simultaneous dexmedetomidine and invasive mechanical ventilation charges, <18 years of age, excluding neonates. Patient and hospital characteristics were compared as well as hospital-level severity-adjusted indexed length of stay (LOS), charges, and mortality.

RESULTS

The utilization of dexmedetomidine increased from 6.2 to 38.2 per 100 ventilated PICU patients among pediatric hospitals. Utilization ranged from 3.8 to 62.8 per 100 in 2013. Few differences in patient demographics and no differences in hospital-level volume/severity of illness measures between high- and low-utilization hospitals occurred. No differences in hospital-level, severity-adjusted indexed outcomes (LOS, charges, and mortality) were found.

CONCLUSION

Wide practice variation in utilization of dexmedetomidine for ventilated PICU patients existed even as use has increased sixfold. Higher utilization was not associated with increased hospital charges or reduced hospital LOS. Further work should define the expected outcome benefits of dexmedetomidine and its appropriate use.

Special considerations in infants and children

Head injury in children is one of the most common causes of death and disability in the US and, increasingly, worldwide. This chapter reviews the causes, patterns, pathophysiology, and treatment of head injury in children across the age spectrum, and compares pediatric head injury to that in adults. Classification of head injury in children can be organized according to severity, pathoanatomic type, or mechanism. Response to injury and repair mechanisms appear to vary at different ages, and these may influence optimal treatment; however, much work is still needed before investigation leads to clearly effective clinical interventions. This is true both for the more severe injuries as well as those at the milder end of the injury spectrum, the latter of which have received increasing attention. In this chapter, neuroassessment tools for each age, newer imaging modalities including magnetic resonance imaging (MRI), and specific pediatric management issues, including intracranial pressure (ICP) monitoring and seizure prophylaxis, are reviewed. Finally, specific head injury patterns and functional outcomes relevant to pediatric patients are discussed. While head injury is common, the number of head-injured children is significantly smaller than the corresponding adult head-injured population. When divided further by specific ages, injury types, and other sources of heterogeneity, properly powered clinical research is likely to require large data sets that will allow for stratification across variables, including age. While much has been learned in the past several decades, further study will be required to determine the best management practices for optimizing recovery in individual pediatric patients. This approach is likely to depend on collaborative international head injury databases that will allow researchers to better understand the nuanced evolution of different types of head injury in patients at each age, and the pathophysiologic, treatment-related, and genetic factors that influence recovery.

Long-term dexmedetomidine use and safety profile among critically ill children and neonates

OBJECTIVE

To determine whether long-term dexmedetomidine dosing is associated with lower opioid and benzodiazepine use without risk of significant hemodynamic changes and/or withdrawal.

DESIGN

Retrospective, observational study.

SETTING

PICU, cardiovascular ICU, and neonatal ICU in a single, tertiary care, academic children's hospital.

SUBJECTS

We included all patients less than or equal to 21 years old, who received dexmedetomidine for greater than or equal to 72 hours from December 2008 to December 2010 resulting in a 98-subject cohort.

INTERVENTIONS

None.

MEASUREMENT AND MAIN RESULTS

The median duration of dexmedetomidine use was 141 hours. A decrease in systolic blood pressure and heart rate was seen after initiation of dexmedetomidine. After dexmedetomidine was discontinued, systolic blood pressure was statistically significantly higher than baseline. Similarly, heart rate showed a significant increase from baseline following discontinuation of dexmedetomidine. Starting dexmedetomidine was not associated with a significant difference in the dosing of opiates or benzodiazepines. Comfort scores were significantly lower at 2 and 72 hours of dexmedetomidine infusion. After stopping dexmedetomidine, the comfort score for patients at 1 hour was statistically higher than for patients at cessation of the infusion. Thirty percent of patients who were taken off dexmedetomidine, whether weaned or abruptly stopped, had withdrawal symptoms and scores recorded with agitation, tremor, and decreased sleep being most prominent.

CONCLUSIONS

Hemodynamic effects of dexmedetomidine did not limit long-term use in this diverse population. After the addition of dexmedetomidine, opioid and benzodiazepine doses did not significantly escalate, and patients were more comfortable as evidenced by decreasing comfort scores. Withdrawal from dexmedetomidine may be an issue and manifests as agitation, tremors, and decreased sleep.

Cardiovascular Effects of Continuous Dexmedetomidine Infusion Without a Loading Dose in the Pediatric Intensive Care Unit

BACKGROUND

Use of dexmedetomidine in pediatric critical care is common, despite lack of prospective studies on its hemodynamic effects.

OBJECTIVE

To describe cardiovascular effects in critically ill children treated with a constant continuous infusion of dexmedetomidine without a loading dose at highest Food and Drug Administration-approved adult dose.

METHODS

Prospective, pilot study of 17 patients with dexmedetomidine infused at a rate of 0.7 μg/kg/h for 6 to 24 hours. Heart rate (HR) and blood pressure (BP) values over time were analyzed by a random effects mixed model.

RESULTS

Patients with median age of 1.6 years (1 month to 17 years) and median weight of 11.8 kg (2.8-84 kg) received an infusion for a mean of 16 ± 7.2 hours. There were no cardiac conduction abnormalities. One patient required discontinuation of infusion for predetermined low HR termination criteria at hour 13 of infusion; there was no clinical compromise and it coincided with planned extubation. Decreased HR of 20% from baseline was found in 35% of patients. The mean HR reduction was largest at hour 13 of infusion with a decrease of 13 ± 17 bpm from baseline, but HR changes over time were not statistically significant. Blood pressure effects included a decrease in 12% and an increase in 29%. There was a small but statistically significant increase in systolic BP of 0.4 mm Hg/h of infusion, P < .001.

CONCLUSION

A continuous infusion of 0.7 μg/kg/h of dexmedetomidine without a loading dose for up to 24 hours in critically ill children had tolerable effects on HR and BP.

Sedation-related outcomes in postoperative management of pediatric laryngotracheal reconstruction

OBJECTIVE

Examine outcomes of varied postoperative sedation management in pediatric patients recovering from single stage laryngotracheal reconstruction.

DESIGN

Retrospective review of 34 patients treated with single stage laryngotracheal reconstruction from 2001 through 2011.

SETTING

Tertiary children's hospital.

METHODS

Patients were divided into 2 groups: those managed postoperatively with sedation, with or without paralysis (group 1), and those managed awake with narcotic pain medication as needed for primary management (group 2). Outcomes were measured as a function of sedation management. Outcomes investigated focused on those related to the success of the airway reconstruction, and those related to sedation management.

RESULTS

Out of 68 cases of laryngotracheal reconstruction reviewed from 2001 to 2011, 34 were single stage reconstructions. Nineteen patients were sedated postoperatively (group 1) and fifteen patients were left awake (group 2). There were no significant differences between groups in airway-related outcomes, including risk of accidental decannulation, revision rates, and need for secondary airway procedures such as balloon dilation. Sedation-related outcomes, specifically focusing on differences in medical management, showed significant increases in rates of withdrawal (p<0.0001), nursing concerns of withdrawal (p<0.0001) and sedation level (p<0.0001), pulmonary complications (OR 7.7, p=0.008), and prolonged hospital stay due to withdrawal (p=0.0005) in patients managed with sedation with or without paralysis. Multivariable regression analysis revealed that duration of sedation was the primary risk factor for increased postoperative morbidity, while younger age, lower weight, and use of a posterior graft were also significant variables assessed.

CONCLUSION

Avoiding sedation as the standard for postoperative management of single stage laryngotracheal reconstruction airway patients leads to an overall decreased risk of morbidity without increasing risk of airway-specific morbidity. This is specifically as related to withdrawal, pulmonary complications, concerns about sedation level and prolonged hospital course, all of which increase significantly with increased level and duration of sedation.

A dose-response study of dexmedetomidine administered as the primary sedative in infants following open heart surgery

OBJECTIVE

To evaluate the dose-response relationship of dexmedetomidine in infants with congenital heart disease postoperative from open heart surgery.

DESIGN

Prospective open-label dose-escalation pharmacokinetic-pharmacodynamic study.

SETTING

Tertiary pediatric cardiac ICU.

PATIENTS

Thirty-six evaluable infants, 1-24 months old, postoperative from open heart surgery requiring mechanical ventilation.

INTERVENTIONS

Cohorts of 12 infants were enrolled sequentially to one of the three IV loading doses of dexmedetomidine (0.35, 0.7, and 1 mcg/kg) over 10 minutes followed by respective continuous infusions (0.25, 0.5, and 0.75 mcg/kg/hr) for up to 24 hours.

MEASUREMENTS AND MAIN RESULTS

Dexmedetomidine plasma concentrations were obtained at timed intervals during and following discontinuation of infusion. Pharmacodynamic variables evaluated included sedation scores, supplemental sedation and analgesia medication administration, time to tracheal extubation, respiratory function, and hemodynamic parameters. Infants achieved a deeper sedation measured by the University of Michigan Sedation Scale score (2.6 vs 1) despite requiring minimal supplemental sedation (0 unit doses/hr) and fewer analgesic medications (0.07 vs 0.15 unit doses/hr) while receiving dexmedetomidine compared with the 12-hour follow-up period. Thirty-one patients were successfully extubated while receiving the dexmedetomidine infusion. Only one patient remained intubated due to oversedation during the infusion. While receiving dexmedetomidine, there was a decrease in heart rate compared with baseline, 132 versus 161 bpm, but there was an increase in heart rate compared with postinfusion values, 132 versus 128 bpm. There was no statistically or clinically significant change in mean arterial blood pressure.

CONCLUSIONS

Dexmedetomidine administration in infants following open heart surgery can provide improved sedation with reduction in supplemental medication requirements, leading to successful extubation while receiving a continuous infusion. The postoperative hemodynamic changes that occur in infants postoperative from open heart surgery are multifactorial. Although dexmedetomidine may play a role in decreasing heart rate immediately postoperative, the changes were not clinically significant and did not fall below postinfusion heart rates.

[Dexmedetomidine. Pharmacokinetics and pharmacodynamics]

Dexmedetomidine is a highly selective, potent α₂-adrenoceptor agonist which was approved in 2011 by the European Medicines Agency for sedation of patients in intensive care units (ICU). Dexmedetomidine exhibits sedative as well as analgesic and anxiolytic effects. Recent studies suggest that dexmedetomidine may be an alternative to midazolam in long-term ICU sedation. This review summarizes the pharmacokinetics and pharmacodynamics of dexmedetomidine particularly in ICU patients and with special regard to covariate effects. Although dexmedetomidine is currently approved only for use in adults the pharmacokinetics and pharmacodynamics in children will also be addressed as there are numerous studies on this off-label use.

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

BACKGROUND

Critically ill children require sedation for comfort and to facilitate mechanical ventilation and interventions. Dexmedetomidine is a newer sedative with little safety data in pediatrics, particularly for therapy lasting longer than 48 h.

OBJECTIVE

To quantify the frequency of adverse events and withdrawal syndromes associated with dexmedetomidine and to describe the use of this drug for continuous sedation in critically ill children.

METHODS

In this retrospective study of patients who received dexmedetomidine for sedation in the pediatric intensive care unit, adverse events were assessed with the Naranjo scale to determine the likelihood of association with dexmedetomidine. Interventions in response to adverse events were also recorded.

RESULTS

One hundred and forty-four patients (median age 34 months, range 0 - 17.7 years) who underwent a total of 153 treatment courses were included. The mean infusion rate of dexmedetomidine was 0.42 μg/kg per hour (standard deviation 0.17 μg/kg per hour, range 0.05-2 μg/kg per hour). The median duration of therapy was 20.50 h (range 0.75-854.75 h), and 70 infusions (46%) lasted more than 24 h. At least one adverse event was observed in 115 (75%) of the treatment courses. Hypotension (81 [53%]) and bradycardia (38 [25%]) were the most common adverse events and were deemed "probably" attributable to dexmedetomidine in 17 (11%) and 9 (6%) of the treatment courses, respectively. In 55 of the 66 treatment courses with infusions lasting longer than 24 h for which post-infusion data were available, at least one withdrawal symptom was observed; agitation (41 [62%]) and hypertension (22 [33%]) were the most common withdrawal symptoms.

CONCLUSIONS

Dexmedetomidine was commonly administered for longer than 24 h in the authors' institution. Dexmedetomidine was generally well tolerated; however, the majority of patients experienced withdrawal symptoms. Patients receiving dexmedetomidine for more than 24 h should be monitored for withdrawal following discontinuation, and interventions should be provided if needed. Prospective, controlled studies are needed to characterize the safety of long-term dexmedetomidine therapy in critically ill children.

Dexmedetomidine as a Primary Sedative Agent after Single-Stage Airway Reconstruction

Objective

To examine the outcomes of children receiving dexmedetomidine after single-stage airway reconstruction.

Study Design

Historical cohort study.

Setting

Tertiary care children’s hospital.

Subjects and Methods

Of 61 eligible patients, 50 children undergoing single-stage airway reconstruction were included in the study. Thirty children received dexmedetomidine (Dex) as a primary sedative agent, and 20 received a more traditional sedation protocol (no Dex). Primary outcomes included complications, intubation lengths, and lengths of pediatric intensive care unit (PICU)/hospital admission. Secondary analysis incorporating polypharmacy and age was performed using multivariate linear regression models.

Results

Median age was 18.0 months. Age, sex, and weight were similar between the groups. Intubation length was equal in the 2 groups, and there were no statistical differences between lengths of PICU or hospital stay after extubation. Similarly, overall and individual complications were all similar, and there was no difference between the 2 groups in the amount of polypharmacy administered. On multivariate analysis, polypharmacy and younger age were independently correlated with an increase in overall complications, and polypharmacy alone was correlated with an increased length of stay after extubation.

Conclusion

The use of dexmedetomidine as a primary sedation agent after single-stage airway surgery does not appear to improve outcomes or decrease the need for additional pharmacologic agents. Polypharmacy was associated with an increase in overall complications and an increased length of stay after extubation. Although success can be expected in greater than 90% of these surgical patients, the optimal postoperative sedation management remains challenging.

[Dexmedetomidine and clonidine: a review of their pharmacodynamy to define their role for sedation in intensive care patients]

Alpha-2 adrenergic agonists ("alpha-2 agonists") present multiple pharmacodynamic effects: rousable sedation, decreased incidence of delirium in the setting of critical care, preservation of respiratory drive, decreased whole body oxygen consumption, decreased systemic and pulmonary arterial impedance, improved left ventricular systolic and diastolic function, preserved vascular reactivity to exogenous catecholamines, preserved vasomotor baroreflex with lowered set point, preserved kidney function, decreased protein catabolism. These pharmacodynamic effects explain the interest for these drugs in the critical care setting. However, their exact role for sedation in critically ill-patients remains open for further studies. Given the few double-blind randomized multicentric trials available, the present non exhaustive analysis of the literature aims at presenting the utilization of alpha-2 agonists as potential first-line sedative agents, in the critical care setting. Suggestions regarding the use of alpha-2 agonists as sedatives are detailed.

In vitro clearance of dexmedetomidine in extracorporeal membrane oxygenation

Dexmedetomidine (DMET) is a useful agent for sedation, both alone and in combination with other agents, in critically ill patients, including those on extracorporeal membrane oxygenation (ECMO) therapy. The drug is a clonidine-like derivative with an 8-fold greater specificity for the alpha 2-receptor while maintaining respiratory and cardiovascular stability. An in vitro ECMO circuit was used to study the effects of both “new” and “old” membrane oxygenators on the clearance of dexmedetomidine over the course of 24 hours. Once primed, the circuit was dosed with 840 μg of dexmedetomidine for a final concentration of 0.9 μg/ml. Serial samples, both pre- and post-oxygenator, were taken at 5, 60, 360, and 1440 minutes. Concentrations of the drug were expressed as a percentage of the original concentration remaining at each time point, both for new and old circuits. The new circuits were run at a standard flow for 24 hours, after which time the circuit was considered old and re-dosed with dexmedetomidine and the trial repeated. Results show that dexmedetomidine losses occur early in the circuits and then continue to decline. Initial losses in the first hour were 11+-65% and 59-73% pre- and post-oxygenator in the new circuit and 36-50% and 42-72% in the old circuit. The clearance of the drug through the membrane oxygenator exhibits no statistical difference between pre and post or new and old circuits. Dexmedetomidine can be expected to exhibit concentration changes during ECMO therapy. This effect appears to be more related to adsorption to the polyvinyl chloride (PVC) tubing rather than the membrane oxygenator. Dosage adjustments during dexmedetomidine administration during ECMO therapy may be warranted in order to maintain adequate serum concentrations and, hence, the desired degree of sedation.*(Lack of equilibrium)

Dexmedetomidine sedation: uses in pediatric procedural sedation outside the operating room

As the field of pediatric procedural sedation continues to expand, so does the exploration of medications that have a role in such invasive and noninvasive procedures. One such medication that has emerged during the last decade is dexmedetomidine, a drug approved for use in the adult intensive care setting. Its role in pediatrics has varied in its use from sedation in ventilated children in the intensive care unit to treatment for emergence reactions from general anesthesia and in sedation needed for radiographic imaging studies, electroencephalography, and invasive procedures. This review article presents the pediatric studies that have been published thus far regarding dexmedetomidate in the nonventilated, spontaneously breathing patient and identifies those patients where the use of this agent may not be indicated.

Clinical report—Guidelines for the determination of brain death in infants and children: an update of the 1987 task force recommendations

OBJECTIVE

To review and revise the 1987 pediatric brain death guidelines.

METHODS

Relevant literature was reviewed. Recommendations were developed using the GRADE system.

CONCLUSIONS AND RECOMMENDATIONS

(1) Determination of brain death in term newborns, infants and children is a clinical diagnosis based on the absence of neurologic function with a known irreversible cause of coma. Because of insufficient data in the literature, recommendations for preterm infants less than 37 weeks gestational age are not included in this guideline. (2) Hypotension, hypothermia, and metabolic disturbances should be treated and corrected and medications that can interfere with the neurologic examination and apnea testing should be discontinued allowing for adequate clearance before proceeding with these evaluations. (3) Two examinations including apnea testing with each examination separated by an observation period are required. Examinations should be performed by different attending physicians. Apnea testing may be performed by the same physician. An observation period of 24 hours for term newborns (37 weeks gestational age) to 30 days of age, and 12 hours for infants and chi (> 30 days to 18 years) is recommended. The first examination determines the child has met the accepted neurologic examination criteria for brain death. The second examination confirms brain death based on an unchanged and irreversible condition. Assessment of neurologic function following cardiopulmonary resuscitation or other severe acute brain injuries should be deferred for 24 hours or longer if there are concerns or inconsistencies in the examination. (4) Apnea testing to support the diagnosis of brain death must be performed safely and requires documentation of an arterial Paco(2) 20 mm Hg above the baseline and ≥ 60 mm Hg with no respiratory effort during the testing period. If the apnea test cannot be safely completed, an ancillary study should be performed. (5) Ancillary studies (electroencephalogram and radionuclide cerebral blood flow) are not required to establish brain death and are not a substitute for the neurologic examination. Ancillary studies may be us d to assist the clinician in making the diagnosis of brain death (i) when components of the examination or apnea testing cannot be completed safely due to the underlying medical condition of the patient; (ii) if there is uncertainty about the results of the neurologic examination; (iii) if a medication effect may be present; or (iv) to reduce the inter-examination observation period. When ancillary studies are used, a second clinical examination and apnea test should be performed and components that can be completed must remain consistent with brain death. In this instance the observation interval may be shortened and the second neurologic examination and apnea test (or all components that are able to be completed safely) can be performed at any time thereafter. (6) Death is declared when the above criteria are fulfilled.

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.