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

Impact of Intravenous Methadone Dosing Schedule on Iatrogenic Withdrawal Syndrome in a Pediatric Intensive Care Unit

OBJECTIVE

To compare median Sophia Observation withdrawal Symptoms scale (SOS) scores between -intravenous methadone dosing scheduled every 6 hours or every 8 hours for iatrogenic withdrawal -syndrome (IWS).

METHODS

This single-center, retrospective chart review evaluated patients aged 4 weeks through 18 years treated with intravenous methadone for IWS. Children admitted to the pediatric intensive care unit (PICU) of a tertiary care children's hospital between August 2017 and July 2021 and treated for IWS for at least 48 hours were eligible for inclusion. Methadone dosing schedules were compared, with a primary outcome of median Sophia Observation withdrawal Symptoms (SOS) score during the first 24 hours after cessation of continuous fentanyl infusion. Secondary outcomes included PICU and general pediatric unit lengths of stay, extubation failure rates, and mortality.

RESULTS

Twenty patients met inclusion criteria, with 9 in the 6-hour dosing group. There was no difference in median SOS score, extubation failure, length of stay, or mortality between the 2 groups.

CONCLUSIONS

During the first 24 hours after cessation of continuous fentanyl, there appears to be no -difference in IWS severity, as determined by bedside nurse scoring, between patients treated with -intravenous methadone every 6 hours compared with every 8 hours.

Delirium in the NICU

Delirium in the NICU is an underrecognized phenomenon in infants who are often complex and critically ill. The current understanding of NICU delirium is developing and can be informed by adult and pediatric literature. The NICU population faces many potential risk factors for delirium, including young age, developmental delay, mechanical ventilation, severe illness, and surgery. There are no diagnostic tools specific to infants. The mainstay of delirium treatment is to treat the underlying cause, address modifiable risk factors, and supportive care. This review will summarize current knowledge and areas where more research is needed.

Dexmedetomidine for the prevention of delirium in adults admitted to the intensive care unit or post-operative care unit: A systematic review of randomised clinical trials with meta-analysis and Trial Sequential Analysis

OBJECTIVES

To assess any benefit or harm, we conducted a systematic review of randomised clinical trials (RCTs) allocating adults to dexmedetomidine versus placebo/no intervention for the prevention of delirium in intensive care or post-operative care units.

DATA SOURCES

We searched Medline, Embase, CENTRAL and other databases. The last search was 9 April 2022.

DATA EXTRACTION

Literature screening, data extraction and risk of bias volume 2 assessments were performed independently and in duplicate. Primary outcomes were occurrences of serious adverse events (SAEs), delirium and all-cause mortality. We used meta-analysis, Trial Sequential Analysis, and GRADE (Grading Recommendations Assessment, Development and Evaluation).

DATA SYNTHESIS

Eighty-one RCTs (15,745 patients) provided data for our primary outcomes. Results from trials at low risk of bias showed that dexmedetomidine may reduce the occurrence of the most frequently reported SAEs (relative risk [RR] 0.69; 95% CI 0.43-1.09), cumulated SAEs (RR 0.70; 95% CI 0.52-0.95) and the occurrence of delirium (RR 0.62; 95% CI 0.43-0.89). The certainty of evidence was very low for delirium. Mortality was very low in trials at low risk of bias (0.4% in the dexmedetomidine groups and 1.0% in the control groups) and meta-analysis did not provide conclusive evidence that dexmedetomidine may result in lower or higher all-cause mortality (RR 0.47; 95% CI 0.18-1.21). There was a lack of information from trial results at low risk of bias for all primary outcomes.

CONCLUSIONS

Trial results at low risk of bias showed that dexmedetomidine might reduce occurrences of SAEs and delirium, while no conclusive evidence was found for effects on all-cause mortality. The certainty of evidence ranged from very low for occurrence of delirium to low for the remaining outcomes.

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.

Biased, Bitopic, Opioid–Adrenergic Tethered Compounds May Improve Specificity, Lower Dosage and Enhance Agonist or Antagonist Function with Reduced Risk of Tolerance and Addiction

This paper proposes the design of combination opioid–adrenergic tethered compounds to enhance efficacy and specificity, lower dosage, increase duration of activity, decrease side effects, and reduce risk of developing tolerance and/or addiction. Combinations of adrenergic and opioid drugs are sometimes used to improve analgesia, decrease opioid doses required to achieve analgesia, and to prolong the duration of analgesia. Recent mechanistic research suggests that these enhanced functions result from an allosteric adrenergic binding site on opioid receptors and, conversely, an allosteric opioid binding site on adrenergic receptors. Dual occupancy of the receptors maintains the receptors in their high affinity, most active states; drops the concentration of ligand required for full activity; and prevents downregulation and internalization of the receptors, thus inhibiting tolerance to the drugs. Activation of both opioid and adrenergic receptors also enhances heterodimerization of the receptors, additionally improving each drug’s efficacy. Tethering adrenergic drugs to opioids could produce new drug candidates with highly desirable features. Constraints—such as the locations of the opioid binding sites on adrenergic receptors and adrenergic binding sites on opioid receptors, length of tethers that must govern the design of such novel compounds, and types of tethers—are described and examples of possible structures provided.

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

STUDY OBJECTIVE

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

DESIGN AND SETTING

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

PATIENTS

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

INTERVENTION

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

MEASUREMENTS

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

MAIN RESULTS

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

CONCLUSIONS

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

Incidence and clinical manifestation of iatrogenic opioid withdrawal syndrome in mechanically ventilated patients

OBJECTIVE

The incidence of iatrogenic opioid withdrawal syndrome (IOWS) in mechanically ventilated adults has been questioned in settings driven by analgosedation strategies. This study aimed to describe the incidence, risk factors and clinical impact of IOWS in mechanically ventilated adults.

METHODS

This prospective, observational study was performed between 1 January and 31 August 2018. IOWS was identified based on the presence of at least three signs or symptoms according to the Diagnostic and Statistical Manual 5th edition (DSM-5) criteria after opioid discontinuation or rate reduction. Incidence of IOWS, patient characteristics, opioid administration, and the impact of IOWS on the duration of mechanical ventilator and length of stay in the intensive care unit (ICU) were collected.

RESULTS

Thirteen out of 55 patients (23.6%) manifested withdrawal symptoms. Two patients in the non-withdrawal group also developed hypertensive urgency after opioid discontinuation. Patients who received rapid once-daily weaning, especially rate reduction more than 50 µg as fentanyl equivalent per hour, were associated with IOWS. However, there was no statistically significant difference in ventilator-free days and ICU-free days.

CONCLUSIONS

These findings showed that approximately one-fourth of mechanically ventilated patients who received opioid infusion experienced IOWS. Monitoring for IOWS is recommended especially in patients who received rapid weaning rate of opioids. Future studies to develop IOWS assessment tools with the change of hemodynamic parameters should be performed.

TRIAL REGISTRATION

This trial was registered in ClinicalTrials.gov: identifier NCT03374722, date of registration 15 December 2018.

Opioid-free anesthesia-dexmedetomidine as adjuvant in erector spinae plane block: a case series

BACKGROUND

Laparoscopic pain is related to the stretching of the peritoneum and peritoneal irritation caused by insufflation of the parietal peritoneum with carbon dioxide. In 2017, erector spinae plane block (ESPB) was described for management of postoperative pain following open and laparoscopic abdominal surgery. The use of multimodal anesthesia reduces both intraoperative and postoperative opioid use and improves analgesia. The addition of dexmedetomidine to the anesthetic mixture significantly prolongs analgesia, without clinically significant side effects.

CASE PRESENTATION

We describe a series of three Caucasian women cases that illustrate the efficacy of bilateral ESPB performed at the level of the T7 transverse process to provide intraoperative and postoperative analgesia for laparoscopic gynecological surgery.

CONCLUSION

Further investigation is recommended to establish the potential for ESPB with dexmedetomidine as adjuvant as an opioid-free anesthetic modality in laparoscopic gynecological surgery.

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.

Protocolized Sedative Weaning vs Usual Care in Pediatric Critically Ill Patients: A Pilot Randomized Controlled Trial

Aims

The prolonged use of benzodiazepines and opioids can lead to an increase in the incidence of withdrawal syndrome. One of the known risk factors is the lack of a sedative-weaning protocol. This study established a sedative-weaning protocol and compared this protocol with the usual care of weaning in high-risk critically ill children.

Materials and methods

This was an open-label, randomized controlled trial in a tertiary-care hospital. We recruited children aged 1 month to 18 years who had received intravenous sedative or analgesic drugs for at least 5 days. The exclusion criteria were patients who had already experienced the withdrawal syndrome. We established a weaning protocol. Eligible patients were randomly divided into the protocolized (intervention) and usual care (control) groups. The primary objective was to determine the prevalence of the withdrawal syndrome compared between two groups.

Results

Thirty eligible patients were enrolled (19 in the intervention and 11 in the control group). Baseline characteristics were not significantly different between both the groups. The prevalence of the withdrawal syndrome was 84% and 81% of patients in the intervention and control group, respectively. The duration of the initial weaning phase was shorter in the intervention group than in the control group (p value = 0.026). The cumulative dose of morphine solution for rescue therapy in the intervention group was statistically lower than that in the control group (p value = 0.016).

Conclusion

The implementation of the sedative-weaning protocol led to a significant reduction in the percentage of withdrawal days and length of intensive care unit stay without any adverse drug reactions. External validation would be needed to validate this protocol.

ClinicalTrials.gov identifier

NCT03018977

How to cite this article

Tiacharoen D, Lertbunrian R, Veawpanich J, Suppalarkbunlue N, Anantasit N. Protocolized Sedative Weaning vs Usual Care in Pediatric Critically Ill Patients: A Pilot Randomized Controlled Trial. Indian J Crit Care Med 2020;24(6):451–458.

Assessment and treatment of the withdrawal syndrome in paediatric intensive care units: Systematic review

BACKGROUND

Sedoanalgesia secondary iatrogenic withdrawal syndrome (IWS) in paediatric intensive units is frequent and its assessment is complex. Therapies are heterogeneous, and there is currently no gold standard method for diagnosis. In addition, the assessment scales validated in children are scarce. This paper aims to identify and describe both the paediatric diagnostic and assessment tools for the IWS and the treatments for the IWS in critically ill paediatric patients.

METHODS

A systematic review was conducted according to the PRISMA guidelines. This review included descriptive and observational studies published since 2000 that analyzed paediatric scales for the evaluation of the iatrogenic withdrawal syndrome and its treatments. The eligibility criteria included neonates, newborns, infants, pre-schoolers, and adolescents, up to age 18, who were admitted to the paediatric intensive care units with continuous infusion of hypnotics and/or opioid analgesics, and who presented signs or symptoms of deprivation related to withdrawal and prolonged infusion of sedoanalgesia.

RESULTS

Three assessment scales were identified: Withdrawal Assessment Tool-1, Sophia Observation Withdrawal Symptoms, and Opioid and Benzodiazepine Withdrawal Score. Dexmedetomidine, methadone and clonidine were revealed as options for the treatment and prevention of the iatrogenic withdrawal syndrome. Finally, the use of phenobarbital suppressed symptoms of deprivation that are resistant to other drugs.

CONCLUSIONS

The reviewed scales facilitate the assessment of the iatrogenic withdrawal syndrome and have a high diagnostic quality. However, its clinical use is very rare. The treatments identified in this review prevent and effectively treat this syndrome. The use of validated iatrogenic withdrawal syndrome assessment scales in paediatrics clinical practice facilitates assessment, have a high diagnostic quality, and should be encouraged, also ensuring nurses' training in their usage.

Antihypertensive agents: a long way to safe drug prescribing in children

Recently updated clinical guidelines have highlighted the gaps in our understanding and management of pediatric hypertension. With increased recognition and diagnosis of pediatric hypertension, the use of antihypertensive agents is also likely to increase. Drug selection to treat hypertension in the pediatric patient population remains challenging. This is primarily due to a lack of large, well-designed pediatric safety and efficacy trials, limited understanding of pharmacokinetics in children, and unknown risk of prolonged exposure to antihypertensive therapies. With newer legislation providing financial incentives for conducting clinical trials in children, along with publication of pediatric-focused guidelines, literature available for antihypertensive agents in pediatrics has increased over the last 20 years. The objective of this article is to review the literature for safety and efficacy of commonly prescribed antihypertensive agents in pediatrics. Thus far, the most data to support use in children was found for angiotensin-converting enzyme inhibitors (ACE-I), angiotensin receptor blockers (ARB), and calcium channel blockers (CCB). Several gaps were noted in the literature, particularly for beta blockers, vasodilators, and the long-term safety profile of antihypertensive agents in children. Further clinical trials are needed to guide safe and effective prescribing in the pediatric population.

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.

Acute Opiate Overdose: An Update on Management Strategies in Emergency Department and Critical Care Unit

BACKGROUND

Opioids are natural, semisynthetic, or synthetic substances that act on opioid receptors in the central nervous system. Clinically, they are prescribed for pain management. Opioid overdose (OOD) occurs when the central nervous system and respiratory drive are suppressed because of excessive consumption of the drug. Symptoms of OOD include drowsiness, slow breathing, pinpoint pupils, cyanosis, loss of consciousness, and death. Due to their addictive potential and easy accessibility opioid addiction is a growing problem worldwide. Emergency medical services and the emergency department often perform initial management of OOD. Thereafter, some patients require intensive care management because of respiratory failure, metabolic encephalopathy, acute kidney injury, and other organ failure.

AREAS OF UNCERTAINTY

We sought to review the literature and present the most up-to-date treatment strategies of patients with acute OOD requiring critical care management.

DATA SOURCES

A PubMed search was conducted to review all articles between 1950 and 2017 and the relevant articles were cited.

RESULTS & CONCLUSIONS

Worldwide, approximately 69,000 people die of OOD each year, and approximately 15 million people have opioid addiction. In the United States, death from OOD has increased almost 5-fold from 2001 to 2013. OOD leading to intensive care unit admission has increased by 50% from 2009 to 2015. At the same time, the mortality associated with these admissions has doubled. The management strategies include airway management, use of reversal agents, assessing and treating coingestions and associated complications, treatment of opioid withdrawal with alpha-agonists, and psychosocial support to help with opiate addiction and withdrawal. This warrants awareness among clinicians regarding the adverse effects associated with opioid use, management strategies, and calls for a multidisciplinary approach to treating these patients.

Dexmedetomidine for the prevention of delirium in critically ill patients - A protocol for a systematic review

BACKGROUND

Delirium is a common complication in critically ill patients and carries an increased risk of mortality and morbidity. Dexmedetomidine can potentially prevent delirium by diminishing predisposing factors. The evidence regarding the use of dexmedetomidine in preventing delirium is conflicting. This protocol aims to identify the beneficial and harmful effects of dexmedetomidine in the prevention of delirium.

METHODS

This protocol uses the recommendations of the Cochrane Collaboration, the Preferred Report Items of Systematic Reviews with Meta-Analysis Protocols, and the eight-step assessment procedure suggested by Jakobsen and colleagues. We wish to assess in critically ill patients, if dexmedetomidine versus placebo can reduce the incidence of delirium and improve clinical outcomes. We will include all randomised trials assessing the use of dexmedetomidine in the prevention of delirium. To identify trials, we will search the Cochrane Central Register of Controlled Trials, Medical Literature Analysis and Retrieval System Online, Excerpta Medica database, Latin American and Caribbean Health Sciences Literature, Science Citation Index Expanded on Web of Science, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, Chinese Science Journal Database, and BIOSIS. Two authors will screen the literature and extract data. We will use the Cochrane risk of bias tool to evaluate trials. Extracted data will be analysed using Review Manager 5 and Trial Sequential Analysis. We will create a "Summary of Findings"-table in which we will present our primary and secondary outcomes. We will assess the quality of evidence using GRADE.

DISCUSSION

This systematic review can potentially aid clinicians in decision-making and benefit the many critically ill patients at risk of delirium.

Dexmedetomidine for the management of delirium in critically ill patients-A protocol for a systematic review

BACKGROUND

Delirium is a common complication in critically ill patients and carries an increased risk of mortality and morbidity. Dexmedetomidine can potentially treat delirium by diminishing predisposing factors. The evidence regarding the use of dexmedetomidine in the management of delirium is conflicting. This protocol aims to identify the beneficial and harmful effects of dexmedetomidine in the management of delirium.

METHODS

This protocol uses the recommendations of the Cochrane Collaboration, the Preferred Report Items of Systematic reviews with Meta-Analysis Protocols, and the eight-step assessment procedure suggested by Jakobsen and colleagues. We wish to assess in critically ill patients with delirium, if dexmedetomidine vs placebo is effective in managing delirium and improving clinical outcomes. We will include all relevant randomised clinical trials assessing the use of dexmedetomidine in treating delirium. To identify trials, we will search the Cochrane Central Register of Controlled Trials, Medical Literature Analysis and Retrieval System Online, Excerpta Medica database, Latin American and Caribbean Health Sciences Literature, Science Citation Index Expanded on Web of Science, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, Chinese Science Journal Database, and BIOSIS. Two authors will screen the literature and extract data. The Cochrane risk of bias tool will be used to evaluate included trials. Extracted data will be analysed using Review Manager 5 and Trial Sequential Analysis. We will create a 'Summary of Findings'-table in which we will present our primary and secondary outcomes. We will assess the quality of evidence using GRADE assessment.

DISCUSSION

This systematic review can potentially aid clinicians in decision making and benefit the many critically ill patients developing delirium.

Interprofessional Team's Perception of Care Delivery After Implementation of a Pediatric Pain and Sedation Protocol

BACKGROUND

Pain and agitation are common experiences of patients in pediatric cardiac intensive care units. Variability in assessments by health care providers, communication, and treatment of pain and agitation creates challenges in management of pain and sedation.

OBJECTIVES

To develop guidelines for assessment and treatment of pain, agitation, and delirium in the pediatric cardiac intensive unit in an academic children's hospital and to document the effects of implementation of the guidelines on the interprofessional team's perception of care delivery and team function.

METHODS

Before and after implementation of the guidelines, interprofessional team members were surveyed about the members' perception of analgesia, sedation, and delirium management RESULTS: Members of the interprofessional team felt more comfortable with pain and sedation management after implementation of the guidelines. Team members reported improvements in team communication on patients' comfort. Members thought that important information was less likely to be lost during transfer of care. They also noted that the team carried out comfort management plans and used pharmacological and nonpharmacological therapies better after implementation of the guidelines than they did before implementation.

CONCLUSIONS

Guidelines for pain and sedation management were associated with perceived improvements in team function and patient care by members of the interprofessional team.

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.

Iatrogenic Opioid Withdrawal in Critically Ill Patients: A Review of Assessment Tools and Management

OBJECTIVE

To (1) provide an overview of the epidemiology, clinical presentation, and risk factors of iatrogenic opioid withdrawal in critically ill patients and (2) conduct a literature review of assessment and management of iatrogenic opioid withdrawal in critically ill patients.

DATA SOURCES

We searched MEDLINE (1946-June 2017), EMBASE (1974-June 2017), and CINAHL (1982-June 2017) with the terms opioid withdrawal, opioid, opiate, critical care, critically ill, assessment tool, scale, taper, weaning, and management. Reference list of identified literature was searched for additional references as well as www.clinicaltrials.gov .

STUDY SELECTION AND DATA EXTRACTION

We restricted articles to those in English and dealing with humans.

DATA SYNTHESIS

We identified 2 validated pediatric critically ill opioid withdrawal assessment tools: (1) Withdrawal Assessment Tool-Version 1 (WAT-1) and (2) Sophia Observation Withdrawal Symptoms Scale (SOS). Neither tool differentiated between opioid and benzodiazepine withdrawal. WAT-1 was evaluated in critically ill adults but not found to be valid. No other adult tool was identified. For management, we identified 5 randomized controlled trials, 2 prospective studies, and 2 systematic reviews. Most studies were small and only 2 studies utilized a validated assessment tool. Enteral methadone, α-2 agonists, and protocolized weaning were studied.

CONCLUSION

We identified 2 validated assessment tools for pediatric intensive care unit patients; no valid tool for adults. Management strategies tested in small trials included methadone, α-2 agonists, and protocolized sedation/weaning. We challenge researchers to create validated tools assessing specifically for opioid withdrawal in critically ill children and adults to direct management.

Is it prime time for alpha2-adrenocepter agonists in the treatment of withdrawal syndromes?

The need to treat withdrawal syndromes is a common occurrence in outpatient, inpatient ward, and intensive care unit (ICU) settings. A PubMed and Google Scholar search using alpha2-adrenoreceptor agonist (A2AA), specific A2AA agents, withdrawal syndrome and nicotine, and alcohol and opioid withdrawal terms was performed. A2AA agents appear to be able to modulate many of the signs and symptoms of significant withdrawal syndromes but are also capable of significant side effects, which can limit clinical use. Non-opioid oral A2AA agent use for opioid withdrawal has been well established. Pharmacologic combination therapy that utilizes A2AA agents for withdrawal syndromes appears promising but requires further formal testing to better define which other agents, under what condition(s), and at what A2AA doses are needed. The A2AA dexmedetomidine may be useful as an adjunctive agent in treating severe alcohol withdrawal syndromes in the ICU. In general, the current data does not support the routine use of A2AA as the primary or sole agent to treat ethanol/alcohol or nicotine withdrawal syndromes. Specific A2AA agents such as lofexidine has been shown to have a primary role in non-opioid-based treatment of opioid withdrawal syndrome and dexmedetomidine in combination with benzodiazepines has been shown to have potential in the treatment of severe ICU-based alcohol withdrawal syndrome.

Calcium channel blocker attenuated opioid withdrawal syndrome

Case

A 61-year-old woman was diagnosed with deep cervical abscess and enlarged mediastinal abscess. These required a protracted period of mechanical ventilation and neck and thoracic drainage surgery with daily wound lavage, necessitating the administration of large amounts of fentanyl and dexmedetomidine. After extubation, fentanyl was discontinued but dexmedetomidine was continued, and she developed hypertension, tachycardia, tachypnea, and hyperthermia within several hours; therefore, she was diagnosed with opioid withdrawal syndrome. Her symptoms failed to improve with either an increased dexmedetomidine dose or a diltiazem infusion for symptomatic management. Ultimately, 20 mg nifedipine was given through a nasogastric tube, which led to a resolution of withdrawal symptoms.

Outcome

This is the first case of calcium channel blockers attenuating opioid withdrawal syndrome symptoms in a human.

Conclusion

Calcium channel blockers might be alternative therapy to refractory opioid withdrawal syndrome. Case accumulation in the future is expected.

The pharmacologic management of delirium in children and adolescents

Delirium is a serious and common problem in severely medically ill patients of all ages. It has been less addressed in children and adolescents. Treatment of delirium is predicated on addressing its underlying cause. The management of its symptoms depends on the off-label use of antipsychotics, while avoiding agents that precipitate or worsen delirium. Olanzapine, quetiapine, and risperidone are presently considered first-line drugs, usually replacing haloperidol. Other agents have shown promise, including melatonin to address the sleep disturbance characteristic of delirium, and dexmedetomidine, an α2-agonist, that may facilitate lower doses of benzodiazepines and opioids that may worsen delirium.

Sedation and analgesia in critically ill children

The interplay of pain, discomfort, and fear can cause agitation in critically ill children. Therefore, sedation and analgesia are essential components in the intensive care unit setting and are best managed with a multidisciplinary team approach. No one standard approach exists to assess and manage pain and anxiety. Many tools are available for the assessment of pain and sedation, but each tool has its advantages and disadvantages. Clinicians should consider adopting a validated tool for routine continuous assessment. Multiple pharmacological therapies are available to manage pain, anxiety, fear, and agitation. Dosing of these agents can be influenced by age-related pharmacokinetic and pharmacodynamic changes. Agents should be selected on the basis of the child's disease state, desired level of sedation, and cardiac and respiratory status.

External Validation of the Medication Taper Complexity Score for Methadone Tapers in Children With Opioid Abstinence Syndrome

Background: Methadone is commonly prescribed for children with opioid abstinence syndrome (OAS) as a taper schedule over several days to weeks. The Medication Taper Complexity Score (MTCS) was developed to evaluate outpatient methadone tapers. Objective: To further validate the MTCS and determine if it is a reliable tool for clinicians to use to assess the complexity of methadone tapers for OAS. Methods: An expert panel of pediatric clinical pharmacists was convened. Panel members were provided 9 methadone tapers (ie, “easy,” “medium,” and “difficult”) to determine construct and face validity of the MTCS. The primary objective was to further establish reliability and construct/face validity of the MTCS. The secondary objective was to assess the reliability of the MTCS within and between tapers. Instrument reliability was assessed using a Pearson correlation coefficient; with 0.8 as the minimum acceptable coefficient. Construct (divergent) validity was assessed via a repeated-measures ANOVA analysis (Bonferroni post hoc analyses) of the mean scores provided by panel members. Results: Six panel members were recruited from various geographical locations. Panel members had 18.3 ± 5.5 years of experience, with practice expertise in general pediatrics, hematology/oncology, and the pediatric and neonatal intensive care unit. The MTCS had a reliability coefficient of .9949. There was vivid discrimination between the easy, medium, and difficult tapers; P = .001. The panel recommended minor modifications to the MTCS. Conclusions: The MTCS was found to be a reliable and valid tool. Overall, the panel felt that the MTCS was easy to use and had potential applications in both practice and research.

Babies breaking bad: neonatal and iatrogenic withdrawal syndromes

PURPOSE OF REVIEW

This review will summarize the symptoms, evaluation, and treatment of neonatal and iatrogenic withdrawal syndromes.

RECENT FINDINGS

Buprenorphine is emerging as the drug of choice for maintaining opioid-dependent women during pregnancy, because of its association with less severe withdrawal symptoms. Recent findings suggest it may be the drug of choice for treating the opioid-exposed neonate as well.

SUMMARY

Healthcare workers should be cognizant of the risk factors for neonatal abstinence syndrome (NAS), as well as its symptoms, so that nonpharmalogic and pharmacologic therapies can be initiated. With increased emphasis on pain control in children, it is likely that iatrogenic withdrawal will continue to be a concern, and healthcare workers should understand the similarities and differences between this and NAS.

Sedation for critically ill or injured adults in the intensive care unit: a shifting paradigm

As most critically ill or injured patients will require some degree of sedation, the goal of this paper was to comprehensively review the literature associated with use of sedative agents in the intensive care unit (ICU). The first and selected latter portions of this article present a narrative overview of the shifting paradigm in ICU sedation practices, indications for uninterrupted or prolonged ICU sedation, and the pharmacology of sedative agents. In the second portion, we conducted a structured, although not entirely systematic, review of the available evidence associated with use of alternative sedative agents in critically ill or injured adults. Data sources for this review were derived by searching OVID MEDLINE and PubMed from their first available date until May 2012 for relevant randomized controlled trials (RCTs), systematic reviews and/or meta-analyses and economic evaluations. Advances in the technology of mechanical ventilation have permitted clinicians to limit the use of sedation among the critically ill through daily sedative interruptions or other means. These practices have been reported to result in improved mortality, a decreased length of ICU and hospital stay and a lower risk of drug-associated delirium. However, in some cases, prolonged or uninterrupted sedation may still be indicated, such as when patients develop intracranial hypertension following traumatic brain injury. The pharmacokinetics of sedative agents have clinical importance and may be altered by critical illness or injury, co-morbid conditions and/or drug-drug interactions. Although use of validated sedation scales to monitor depth of sedation is likely to reduce adverse events, they have no utility for patients receiving neuromuscular receptor blocking agents. Depth of sedation monitoring devices such as the Bispectral Index (BIS©) also have limitations. Among existing RCTs, no sedative agent has been reported to improve the risk of mortality among the critically ill or injured. Moreover, although propofol may be associated with a shorter time to tracheal extubation and recovery from sedation than midazolam, the risk of hypertriglyceridaemia and hypotension is higher with propofol. Despite dexmedetomidine being linked with a lower risk of drug-associated delirium than alternative sedative agents, this drug increases risk of bradycardia and hypotension. Among adults with severe traumatic brain injury, there are insufficient data to suggest that any single sedative agent decreases the risk of subsequent poor neurological outcomes or mortality. The lack of examination of confounders, including the type of healthcare system in which the investigation was conducted, is a major limitation of existing pharmacoeconomic analyses, which likely limits generalizability of their results.

Replacement of fentanyl infusion by enteral methadone decreases the weaning time from mechanical ventilation: a randomized controlled trial

INTRODUCTION

Patients undergoing mechanical ventilation (MV) are frequently administered prolonged and/or high doses of opioids which when removed can cause a withdrawal syndrome and difficulty in weaning from MV. We tested the hypothesis that the introduction of enteral methadone during weaning from sedation and analgesia in critically ill adult patients on MV would decrease the weaning time from MV.

METHODS

A double-blind randomized controlled trial was conducted in the adult intensive care units (ICUs) of four general hospitals in Brazil. The 75 patients, who met the criteria for weaning from MV and had been using fentanyl for more than five consecutive days, were randomized to the methadone (MG) or control group (CG). Within the first 24 hours after study enrollment, both groups received 80% of the original dose of fentanyl, the MG received enteral methadone and the CG received an enteral placebo. After the first 24 hours, the MG received an intravenous (IV) saline solution (placebo), while the CG received IV fentanyl. For both groups, the IV solution was reduced by 20% every 24 hours. The groups were compared by evaluating the MV weaning time and the duration of MV, as well as the ICU stay and the hospital stay.

RESULTS

Of the 75 patients randomized, seven were excluded and 68 were analyzed: 37 from the MG and 31 from the CG. There was a higher probability of early extubation in the MG, but the difference was not significant (hazard ratio: 1.52 (95% confidence interval (CI) 0.87 to 2.64; P = 0.11). The probability of successful weaning by the fifth day was significantly higher in the MG (hazard ratio: 2.64 (95% CI: 1.22 to 5.69; P < 0.02). Among the 54 patients who were successfully weaned (29 from the MG and 25 from the CG), the MV weaning time was significantly lower in the MG (hazard ratio: 2.06; 95% CI 1.17 to 3.63; P < 0.004).

CONCLUSIONS

The introduction of enteral methadone during weaning from sedation and analgesia in mechanically ventilated patients resulted in a decrease in the weaning time from MV.

Selection of the initial methadone regimen for the management of iatrogenic opioid abstinence syndrome in critically ill children

Iatrogenic opioid abstinence syndrome (IOAS) is a common complication in critically ill infants and children receiving prolonged exposure to continuous infusions of opioids. Although no guidelines are available regarding management of IOAS in children, several treatment options are available, including clonidine, morphine, and methadone. Methadone is commonly prescribed due to its long half-life and antagonism of the N-methyl-d-aspartate receptor. Different approaches, such as weight-based and formula-based methods, have been used to determine the initial methadone dosing regimen. Because of the vast differences in the recommended dosing regimen from these sources, we conducted a literature search to identify articles evaluating the initial methadone dosing regimen for prevention and/or treatment of IOAS in children. Specifically, we evaluated the reported frequency of withdrawal and oversedation after initiation of methadone treatment. Our literature search was limited to English-language articles in the MEDLINE (1950-March 2011), EMBASE (1988-March 2011), International Pharmaceutical Abstracts (1970-March 2011), and Cochrane Library (1996-March 2011) databases. Relevant abstracts and reference citations were also reviewed. A total of eight reports representing 183 patients were included in the analysis. There was wide discrepancy in the initial methadone dosing regimen. Approximately one-third of all patients experienced withdrawal after starting methadone, and there did not appear to be a difference between weight-based and formula-based regimens. Seven patients experienced oversedation; however, not all articles reported this complication. It appears that a standard approach to initial methadone dosing does not exist because withdrawal occurred despite the regimen started. Therefore, it seems best to begin with the lowest dose possible and titrate to the child's response to avoid complications such as oversedation. Routine monitoring should be performed in all patients to guide clinicians in the management of IOAS.

A pilot study assessing the frequency and complexity of methadone tapers for opioid abstinence syndrome in children discharged to home

BACKGROUND

Methadone is often prescribed as a taper schedule to prevent/treat opioid abstinence syndrome (OAS) or neonatal abstinence syndrome (NAS).

OBJECTIVE

The objective of this study was to determine the percentage of children discharged home on methadone tapers and to develop, assess, and implement an instrument for measuring the complexity of the methadone regimens.

METHODS

This study used a descriptive retrospective design to examine patients younger than 18 years from January 1, 2008, to December 31, 2008, administered methadone for prevention/treatment of OAS/NAS and discharged home on a methadone taper. Data collection included demographics and characteristics of methadone regimen. The primary objective was to determine the percentage of children discharged on methadone. Secondary objectives included characterization (ie, number of dosage and interval changes), duration, and complexity of the methadone taper. Descriptive statistics were performed using Stata v10 (StataCorp LP, College Station, TX). Complexity was evaluated using the medication taper complexity score (MTCS) between 4 raters. Reliability of the MTCS was established using interrater correlation analyses of the regimen complexity scores.

RESULTS

Thirty-three patients (41.8%) were discharged on methadone. The median (range) age was 0.42 (0-12) years, with most patients (75.8%) initiated on methadone for prevention of OAS. Thirty-one patients were included for further analysis of medication complexity. The median (range) duration of the home taper was 8 days (2-48), which included a median (range) of 4 (1-11) dose changes and at least 1 (0-2) change in the interval. MTCS ranged from 7 to 42, with the tool demonstrating 95% interrater reliability.

CONCLUSIONS

More than one-third of patients were discharged home on methadone. The median taper duration was 8 days and included a median of 5 adjustments in either the dose or interval. The MTCS demonstrated very good interrater reliability to measure wide variability in the complexity of individual tapers. Future studies should determine the construct validity of the MTCS and the applicability of this tool for further research and clinical application.

Validity and generalizability of the Withdrawal Assessment Tool-1 (WAT-1) for monitoring iatrogenic withdrawal syndrome in pediatric patients

Critically ill pediatric patients frequently receive prolonged analgesia and sedation to provide pain relief and facilitate intensive care therapies. Iatrogenic withdrawal syndrome occurs when these drugs are stopped abruptly or weaned too rapidly. We investigated the validity and generalizability of the Withdrawal Assessment Tool-1 (WAT-1) in children during weaning of analgesics and sedatives. Of 308 children initially supported on mechanical ventilation for acute respiratory failure, 126 (41%) from 21 centers (median age 1.6 years; interquartile range 0.6-7.7 years) were exposed to 5 or more days of opioids. Subjects were assessed for withdrawal symptoms with the WAT-1, an 11-item (12-point) scale, from the first day of weaning from analgesia/sedation until 72 h after the last opioid dose. A total of 836 daily WAT-1 assessments were completed, with a median (interquartile range) WAT-1 score of 2 (0-4) over 6 (3-9) days per subject. There were no significant differences in WAT-1 scores as a function of age. Factor analyses confirmed that motor-related symptoms and behavioral state accounted for the most variance in WAT-1 scores. Supporting construct validity, cumulative opioid exposures were greater [40.2 (19.7-83.4) vs 17.6 (14.6-39.7) mg/kg, P=.004], length of opioid treatment before weaning was longer [7 (6-11) vs 5 (5-8)days, P=.004], and length of weaning from opioids was longer [10 (6-14) vs 6 (3-9)days, P=.008] in subjects with WAT-1 scores of ≥ 3 compared to subjects with WAT-1 scores of <3. The WAT-1 shows good psychometric performance and generalizability when used to assess clinically important withdrawal symptoms in pediatric intensive care and general ward settings.

Acute Pain Management in Opioid-Tolerant Patients: A Growing Challenge

In Australia and New Zealand, in parallel with other developed countries, the number of patients prescribed opioids on a long-term basis has grown rapidly over the last decade. The burden of chronic pain is more widely recognised and there has been an increase in the use of opioids for both cancer and non-cancer indications. While the prevalence of illicit opioid use has remained relatively stable, the diversion and abuse of prescription opioids has escalated, as has the number of individuals receiving methadone or buprenorphine pharmacotherapy for opioid addiction. As a result, the proportion of opioid-tolerant patients requiring acute pain management has increased, often presenting clinicians with greater challenges than those faced when treating the opioid-naïve.

Treatment aims include effective relief of acute pain, prevention of drug withdrawal, assistance with any related social, psychiatric and behavioural issues, and ensuring continuity of long-term care. Pharmacological approaches incorporate the continuation of usual medications (or equivalent), short-term use of sometimes much higher than average doses of additional opioid, and prescription of non-opioid and adjuvant drugs, aiming to improve pain relief and attenuate opioid tolerance and/or opioid-induced hyperalgesia. Discharge planning should commence at an early stage and may involve the use of a ‘Reverse Pain Ladder’ aiming to limit duration of additional opioid use. Legislative requirements may restrict which drugs can be prescribed at the time of hospital discharge. At all stages, there should be appropriate and regular consultation and liaison with the patient, other treating teams and specialist services.

The World Federation of Societies of Biological Psychiatry (WFSBP) guidelines for the biological treatment of substance use and related disorders. Part 2: Opioid dependence

OBJECTIVES

To develop evidence-based practice guidelines for the pharmacological treatment of opioid abuse and dependence.

METHODS

An international task force of the World Federation of Societies of Biological Psychiatry (WFSBP) developed these practice guidelines after a systematic review of the available evidence pertaining to the treatment of opioid dependence. On the basis of the evidence, the Task Force reached a consensus on practice recommendations, which are intended to be clinically and scientifically meaningful for physicians who treat adults with opioid dependence. The data used to develop these guidelines were extracted primarily from national treatment guidelines for opioid use disorders, as well as from meta-analyses, reviews, and publications of randomized clinical trials on the efficacy of pharmacological and other biological treatments for these disorders. Publications were identified by searching the MEDLINE database and the Cochrane Library. The literature was evaluated with respect to the strength of evidence for efficacy, which was categorized into one of six levels (A-F).

RESULTS

There is an excellent evidence base supporting the efficacy of methadone and buprenorphine or the combination of buprenorphine and naloxone for the treatment of opioid withdrawal, with clonidine and lofexidine as secondary or adjunctive medications. Opioid maintenance with methadone and buprenorphine is the best-studied and most effective treatment for opioid dependence, with heroin and naltrexone as second-line medications.

CONCLUSIONS

There is enough high quality data to formulate evidence-based guidelines for the treatment of opioid abuse and dependence. This task force report provides evidence for the efficacy of a number of medications to treat opioid abuse and dependence, particularly the opioid agonists methadone or buprenorphine. These medications have great relevance for clinical practice.

Study of adrenergic, imidazoline, and endothelin receptors in clonidine-, morphine-, and oxycodone-induced changes in rat body temperature

OBJECTIVES

The potentiation of morphine or oxycodone analgesia by endothelin-A (ET(A)) receptor antagonists and imidazoline/α(2)-adrenergic agonists is well documented. However, the effect of morphine or oxycodone in combination with an ET(A) receptor antagonist or an imidazoline/α(2) adrenergic agonist on body temperature is not known. The present study was carried out to study the role of ET(A) and imidazoline/α(2) adrenergic receptors in body temperature effects of morphine, oxycodone, and clonidine in rats.

METHODS

Body temperature was determined in male Sprague-Dawley rats treated with morphine, oxycodone, or clonidine. Yohimbine, idazoxan, and BMS182874 were used to determine the involvement of α(2)-adrenergic, imidazoline, and ET(A) receptors, respectively.

KEY FINDINGS

Morphine and oxycodone produced hyperthermia which was not affected by α(2)-adrenergic antagonist yohimbine, imidazoline/α(2)-adrenergic antagonist idazoxan, or ET(A) receptor antagonist BMS182874. Clonidine alone produced hypothermia that was comparable to the hypothermia observed with clonidine plus morphine or oxycodone. The hypothermic effect of clonidine was blocked by idazoxan and yohimbine. The blockade by idazoxan was more pronounced compared to yohimbine. Clonidine hypothermia was not affected by BMS182874.

CONCLUSIONS

This is the first report demonstrating that ET(A) receptors do not influence morphine- and oxycodone- induced hyperthermia or clonidine-induced hypothermia. Imidazoline receptors and α(2)-adrenergic receptors are involved in clonidine-induced hypothermia, but not in morphine- and oxycodone-induced hyperthermia.

Tolerance and withdrawal from prolonged opioid use in critically ill children

OBJECTIVE

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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