Strategies for the Prevention and Treatment of Iatrogenic Withdrawal from Opioids and Benzodiazepines in Critically Ill Neonates, Children and Adults: A Systematic Review of Clinical Studies

Pharmacologic Management of Pediatric Burns

Many pediatric patients with burn injuries may be initially treated in a hospital where pediatric specialized care, including resources and trained personnel may be limited. This includes resuscitation in adult emergency departments and inpatient care in mixed adult-pediatric burn units. The intent of this review is to provide a compilation of topics for the adult trained pharmacist or another healthcare practitioner on the management of pediatric patients with burn injuries. This article focuses on several key areas of pharmacologic burn management in the pediatric patient that may differ from the adult patient, including pain and sedation, fluid resuscitation, nutrition support, antimicrobial selection, anticoagulation, and inhalation injury. It is important that all clinicians have resources to help optimize the management of burn injuries in the pediatric population as, in addition to burn injury itself, pediatric patients have different pharmacokinetics and pharmacodynamics affecting which medications are used and how they are dosed. This article highlights several key differences between pediatric and adult patients, providing an additional resource to assist adult-trained pharmacists or other healthcare practitioners with making clinical decisions in the pediatric burn population.

Seizures in 3 juvenile dogs after intravenous anesthetic drug withdrawal during weaning from mechanical ventilation suspected to be a sign of iatrogenic withdrawal syndrome

OBJECTIVE

To describe seizure activity in juvenile dogs successfully weaned from long-term mechanical ventilation.

CASE SERIES SUMMARY

Three juvenile dogs (all approximately 3 months old) underwent long-term mechanical ventilation with IV anesthesia for suspected noncardiogenic pulmonary edema. Within 24 hours of extubation and within 10 hours of discontinuing midazolam continuous infusions, all dogs experienced seizures, which is 1 sign of iatrogenic withdrawal syndrome. Each dog was treated with an anticonvulsant protocol, and none experienced seizures after being discharged.

NEW OR UNIQUE INFORMATION PROVIDED

Each dog received IV anesthesia, including fentanyl, dexmedetomidine, midazolam, and propofol, during mechanical ventilation and subsequently experienced seizures after successful weaning from mechanical ventilation. Juvenile dogs may be at risk for seizures after weaning from mechanical ventilation and IV anesthesia. Neurological monitoring and further research into an appropriate weaning protocol may prove beneficial in juvenile dogs requiring prolonged anesthesia.

International Analgesia and Sedation Weaning and Withdrawal Practices in Critically Ill Adults: The Adult Iatrogenic Withdrawal Study in the ICU

OBJECTIVES

Iatrogenic withdrawal syndrome (IWS) associated with opioid and sedative use for medical purposes has a reported high prevalence and associated morbidity. This study aimed to determine the prevalence, utilization, and characteristics of opioid and sedative weaning and IWS policies/protocols in the adult ICU population.

DESIGN

International, multicenter, observational, point prevalence study.

SETTING

Adult ICUs.

PATIENTS

All patients aged 18 years and older in the ICU on the date of data collection who received parenteral opioids or sedatives in the previous 24 hours.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

ICUs selected 1 day for data collection between June 1 and September 30, 2021. Patient demographic data, opioid and sedative medication use, and weaning and IWS assessment data were collected for the previous 24 hours. The primary outcome was the proportion of patients weaned from opioids and sedatives using an institutional policy/protocol on the data collection day. There were 2,402 patients in 229 ICUs from 11 countries screened for opioid and sedative use; 1,506 (63%) patients received parenteral opioids, and/or sedatives in the previous 24 hours. There were 90 (39%) ICUs with a weaning policy/protocol which was used in 176 (12%) patients, and 23 (10%) ICUs with an IWS policy/protocol which was used in 9 (0.6%) patients. The weaning policy/protocol for 47 (52%) ICUs did not define when to initiate weaning, and the policy/protocol for 24 (27%) ICUs did not specify the degree of weaning. A weaning policy/protocol was used in 34% (176/521) and IWS policy/protocol in 9% (9/97) of patients admitted to an ICU with such a policy/protocol. Among 485 patients eligible for weaning policy/protocol utilization based on duration of opioid/sedative use initiation criterion within individual ICU policies/protocols 176 (36%) had it used, and among 54 patients on opioids and/or sedatives ≥ 72 hours, 9 (17%) had an IWS policy/protocol used by the data collection day.

CONCLUSIONS

This international observational study found that a small proportion of ICUs use policies/protocols for opioid and sedative weaning or IWS, and even when these policies/protocols are in place, they are implemented in a small percentage of patients.

Critical care nurses' experiences of caring for patients with iatrogenic opioid withdrawal in the intensive care unit: A qualitative study

OBJECTIVES

To explore critical care nurses' experiences of caring for adult patients experiencing iatrogenic opioid withdrawal in the intensive care unit.

RESEARCH METHODOLOGY/DESIGN

A qualitative study with an explorative and descriptive design was conducted. Data were collected through semi-structured interviews and systematic text condensation was used to analyse the data. The study was reported according to the consolidated criteria for reporting qualitative research checklist.

SETTING AND PARTICIPANTS

Ten critical care nurses, working at three different intensive care units in two university hospitals in Norway.

FINDINGS

Three categories were identified in the data analysis. "Subtle signs and symptoms of opioid withdrawal", lack of a systematic approach to opioid withdrawal, and the prerequisites for appropriate management of opioid withdrawal. Critical care nurses experienced challenges in identifying opioid withdrawal due to subtle and vague signs and symptoms, especially when not knowing their patient or when difficulties were encountered with patient communication. A systematic approach to opioid withdrawal and increased knowledge, definitive plans for weaning, as well as interdisciplinary unity and collaboration, could improve the management of opioid withdrawal.

CONCLUSION

Validated assessment tools, systematic strategies, and guidelines are essential for the management of opioid withdrawal in opioid naïve patients in intensive care units. The prerequisites for an appropriate management of opioid withdrawal are an accurate and effective communication among critical care nurses and other healthcare professionals involved in patient care.

IMPLICATIONS FOR CLINICAL PRACTICE

There is a need for a validated assessment tool, systematic strategies, and guidelines for the management of opioid withdrawal in opioid naïve patients in intensive care units. Increased emphasis needs to be placed on the process of identifying iatrogenic opioid withdrawal and improving opioid withdrawal management in the education system and clinical practice.

Opioid, sedative, preadmission medication and iatrogenic withdrawal risk in UK adult critically ill patients: a point prevalence study

BACKGROUND

Iatrogenic withdrawal syndrome, after exposure medication known to cause withdrawal is recognised, yet under described in adult intensive care.

AIM

To investigate, opioid, sedation, and preadmission medication practice in critically ill adults with focus on aspects associated with iatrogenic withdrawal syndrome.

METHOD

One-day point prevalence study in UK intensive care units (ICUs). We collected ICU admission medication and/or substances with withdrawal potential, sedation policy, opioid and sedative use, dose, and duration.

RESULTS

Thirty-seven from 39 participating ICUs contributed data from 386 patients. The prevalence rate for parenteral opioid and sedative medication was 56.1% (212 patients). Twenty-three ICUs (59%) had no sedation/analgesia policy, and no ICUs screened for iatrogenic withdrawal. Patient admission medications with withdrawal-potential included antidepressants or antipsychotics (43, 20.3%) and nicotine (41, 19.3%). Of 212 patients, 202 (95.3%) received opioids, 163 (76.9%) sedatives and 153 (72.2%) both. Two hundred and two (95.3%) patients received opioids: 167 (82.7%) by continuous infusions and 90 (44.6%) patients for longer than 96-h. One hundred and sixty-three (76.9%) patients received sedatives: 157 (77.7%) by continuous infusions and 74 (45.4%) patients for longer than 96-h.

CONCLUSION

Opioid sedative and admission medication with iatrogenic withdrawal syndrome potential prevalence rates were high, and a high proportion of ICUs had no sedative/analgesic policies. Nearly half of patients received continuous opioids and sedatives for longer than 96-h placing them at high risk of iatrogenic withdrawal. No participating unit reported using a validated tool for iatrogenic withdrawal assessment.

Assessment and management of iatrogenic withdrawal syndrome and delirium in pediatric intensive care units across Europe: An ESPNIC survey

INTRODUCTION

Analgesia and sedation are essential for the care of children in the pediatric intensive care unit (PICU); however, when prolonged, they may be associated with iatrogenic withdrawal syndrome (IWS) and delirium. We sought to evaluate current practices on IWS and delirium assessment and management (including non-pharmacologic strategies as early mobilization) and to investigate associations between the presence of an analgosedation protocol and IWS and delirium monitoring, analgosedation weaning, and early mobilization.

METHODS

We conducted a multicenter cross-sectional survey-based study collecting data from one experienced physician or nurse per PICU in Europe from January to April 2021. We then investigated differences among PICUs that did or did not follow an analgosedation protocol.

RESULTS

Among 357 PICUs, 215 (60%) responded across 27 countries. IWS was systematically monitored with a validated scale in 62% of PICUs, mostly using the Withdrawal Assessment Tool-1 (53%). The main first-line treatment for IWS was a rescue bolus with interruption of weaning (41%). Delirium was systematically monitored in 58% of PICUs, mostly with the Cornell Assessment of Pediatric Delirium scale (48%) and the Sophia Observation Scale for Pediatric Delirium (34%). The main reported first-line treatment for delirium was dexmedetomidine (45%) or antipsychotic drugs (40%). Seventy-one percent of PICUs reported to follow an analgosedation protocol. Multivariate analyses adjusted for PICU characteristics showed that PICUs using a protocol were significantly more likely to systematically monitor IWS (odds ratio [OR] 1.92, 95% confidence interval [CI] 1.01-3.67) and delirium (OR 2.00, 95% CI 1.07-3.72), use a protocol for analgosedation weaning (OR 6.38, 95% CI 3.20-12.71) and promote mobilization (OR 3.38, 95% CI 1.63-7.03).

CONCLUSIONS

Monitoring and management of IWS and delirium are highly variable among European PICUs. The use of an analgosedation protocol was associated with an increased likelihood of monitoring IWS and delirium, performing a structured analgosedation weaning and promoting mobilization. Education on this topic and interprofessional collaborations are highly needed to help reduce the burden of analgosedation-associated adverse outcomes.

The Neonatal Withdrawal Assessment Tool (NWAT): pilot inter-rater reliability and content validity

OBJECTIVE

There is no validated tool to assess iatrogenic opioid withdrawal in preterm infants in the newborn intensive care unit (NICU).

STUDY DESIGN

The Neonatal Withdrawal Assessment Tool (NWAT) was developed to address this gap in clinical practice. In this pilot study, the NWAT was assessed for inter-rater reliability (IRR) and content validity.

RESULT

Fifty-one NICU providers scored two standardized simulated cases, then 20 paired provider assessments were completed on 5 preterm infants. The overall IRR was 95.6% on the simulated cases, and 98.8% on the 5 pilot infants. A provider survey assessed for content validity; all of the provider participants strongly agreed/agreed that the NWAT adequately measures withdrawal in critically ill infants.

CONCLUSION

The NWAT demonstrated high IRR and content validity for assessment of iatrogenic opioid withdrawal in preterm infants in this pilot study. Further studies in a larger more diverse patient population are needed before wider adoption into clinical practice.

Mechanical ventilation in snake envenomation of dogs and cats

Envenomation by snakes in Elapidae and Viperidae families have been associated with respiratory failure in dogs and cats. Mechanical ventilation may be required for hypoventilation due to neuromuscular paralysis or hypoxemia due to pulmonary hemorrhage or aspiration pneumonia. Median incidence of dogs and cats with snake envenomation that require mechanical ventilation is 13% (0.06-40%). Standard treatment of snake envenomation in dogs and cats includes prompt administration of appropriate antivenom and management of envenomation complications such as coagulopathy, rhabdomyolysis and acute kidney injury. When mechanical ventilation is required, overall prognosis is good with appropriate treatment. Standard anesthetic protocols and mechanical ventilator settings are generally appropriate, with lung protective ventilation strategies typically reserved for patients with pulmonary disease. Median survival to discharge for cats and dogs with elapid envenomation is 72% (76-84%) with 33 h (19.5-58 h) median duration of mechanical ventilation and 140 h (84-196 h) median hospitalization. This article reviews indications for mechanical ventilation in cats and dogs with snake envenomation, and discusses ventilator settings, anesthetic and nursing considerations, complications and outcomes specific to this disease.

Implementation of an Opioid Weaning Protocol at a Tertiary Care Children's Hospital

OBJECTIVES

Evaluate the implementation of a pharmacist-managed opioid weaning regimen and objective opioid withdrawal assessment tool in pediatric patients requiring an opioid wean. We hypothesized that this combination would be associated with a reduction in the wean duration and length of stay and decrease episodes of opioid withdrawal.

METHODS

Retrospective cohort study utilizing pediatric inpatients requiring an inpatient opioid medication wean. The study was conducted in 3 phases from chart review of patients admitted from 2012 to 2020: baseline preintervention (phase 1), pharmacist-managed weaning regimen (phase 2), and addition of an objective assessment tool, the Withdrawal Assessment Tool-1 (phase 3). Data collection included the total wean duration, total duration of hospital admission, and number of episodes of opioid withdrawal.

RESULTS

The study included 115 patients with 36 patients in phases 1 and 3 and 43 patients in phase 2. Median age ranged from 0.46 to 0.84 years and the majority of children were males. No significant differences in patient characteristics such as age, weight, sex, and previous opioid exposure were found between phases. Length of stay, wean duration, and episodes of withdrawal with need for rescue dose all decreased significantly from phase 1 to phase 3.

CONCLUSIONS

Use of a pharmacist-managed weaning regimen combined with the Withdrawal Assessment Tool-1 tool was associated with significantly shorter methadone weans and overall length of stay. This has implications for wide spread dissemination and standardization of this approach in tertiary care children's hospitals caring for patients after ICU admission.

Strategies for the management and prevention of withdrawal syndrome in critically ill pediatric patients: a systematic review

OBJECTIVE

To verify strategies for the prevention and treatment of abstinence syndrome in a pediatric intensive care unit.

METHODS

This is a systematic review in the PubMed database®, Lilacs, Embase, Web of Science, Cochrane, Cinahl, Cochrane Database Systematic Review and CENTRAL. A three-step search strategy was used for this review, and the protocol was approved in PROSPERO (CRD42021274670).

RESULTS

Twelve articles were included in the analysis. There was great heterogeneity among the studies included, especially regarding the therapeutic regimens used for sedation and analgesia. Midazolam doses ranged from 0.05mg/kg/hour to 0.3mg/kg/hour. Morphine also varied considerably, from 10mcg/kg/hour to 30mcg/kg/hour, between studies. Among the 12 selected studies, the most commonly used scale for the identification of withdrawal symptoms was the Sophia Observational Withdrawal Symptoms Scale. In three studies, there was a statistically significant difference in the prevention and management of the withdrawal syndrome due to the implementation of different protocols (p < 0.01 and p < 0.001).

CONCLUSION

There was great variation in the sedoanalgesia regimen used by the studies and the method of weaning and evaluation of withdrawal syndrome. More studies are needed to provide more robust evidence about the most appropriate treatment for the prevention and reduction of withdrawal signs and symptoms in critically ill children.

PROSPERO REGISTER

CRD 42021274670.

Strategies for the management and prevention of withdrawal syndrome in critically ill pediatric patients: a systematic review

OBJECTIVE

To verify strategies for the prevention and treatment of abstinence syndrome in a pediatric intensive care unit.

METHODS

This is a systematic review in the PubMed database®, Lilacs, Embase, Web of Science, Cochrane, Cinahl, Cochrane Database Systematic Review and CENTRAL. A three-step search strategy was used for this review, and the protocol was approved in PROSPERO (CRD42021274670).

RESULTS

Twelve articles were included in the analysis. There was great heterogeneity among the studies included, especially regarding the therapeutic regimens used for sedation and analgesia. Midazolam doses ranged from 0.05mg/kg/hour to 0.3mg/kg/hour. Morphine also varied considerably, from 10mcg/kg/hour to 30mcg/kg/hour, between studies. Among the 12 selected studies, the most commonly used scale for the identification of withdrawal symptoms was the Sophia Observational Withdrawal Symptoms Scale. In three studies, there was a statistically significant difference in the prevention and management of the withdrawal syndrome due to the implementation of different protocols (p < 0.01 and p < 0.001).

CONCLUSION

There was great variation in the sedoanalgesia regimen used by the studies and the method of weaning and evaluation of withdrawal syndrome. More studies are needed to provide more robust evidence about the most appropriate treatment for the prevention and reduction of withdrawal signs and symptoms in critically ill children.

PROSPERO REGISTER

CRD 42021274670.

Opioid Weaning Protocol Using Morphine Compared With Nonprotocolized Methadone Associated With Decreased Dose and Duration of Opioid After Norwood Procedure

OBJECTIVES

Opioids are used to manage pain, comfort, maintain devices, and decrease oxygen consumption around Norwood palliation (NP), but in high dose and prolonged exposure, they increase risk of tolerance and iatrogenic withdrawal syndrome (IAWS). Variability in practice for IAWS prevention potentially increases opioid dose and duration. We hypothesize that protocolized weaning with morphine (MOR) versus nonprotocolized methadone (MTD) is associated with reduction in opioid exposure.

DESIGN

A before-versus-after study of outcomes of patients weaned with protocolized MOR versus nonprotocolized MTD including subset analysis for those patients with complications postoperatively. Primary endpoints include daily, wean phase, and total morphine milligram equivalent (MMEq) dose, duration, and, secondarily, length of stay (LOS).

SETTING

Quaternary-care pediatric cardiac ICU.

PATIENTS

Neonates undergoing single-ventricle palliation.

INTERVENTIONS

Introduction of IAWS prevention protocol.

MEASUREMENTS AND MAIN RESULTS

Analysis included 54 patients who underwent the NP in 2017-2018 including the subset analysis of 34 who had a complicated postoperative course. The total and wean phase opioid doses for the MTD group were significantly higher than that for the MOR group: 258 versus 22 and 115 versus 6 MMEq/kg; p < 0.001. Duration of opioid exposure was 63 days in the MTD group and 12 days in MOR group (p < 0.001). Subanalysis of the complicated subset also identifies higher total and wean dose for MTD group (293 vs 41 and 116 vs 7 MMEq/kg; p < 0.001) with a longer duration (65 vs 22 days; p = 0.001). Within the subset, LOS was 55% longer in the MTD group than that in the MOR group (150 vs 67 d; p = 0.01) and not different in the uncomplicated group.

CONCLUSIONS

After complex NP, a protocolized opioid weaning using MOR versus MTD is associated with 65% shorter opioid duration, 10-fold decreased dose, and shortened LOS.

Intravenous opioids for chemotherapy-induced severe mucositis pain in children: Systematic review and single-center case series of management with patient- or nurse-controlled analgesia (PCA/NCA)

BACKGROUND

Chemotherapy-induced oral mucositis can result in severe pain. Intravenous (IV) opioids are recommended, but management protocols vary. We systematically reviewed studies reporting IV opioid use for pain related to chemotherapy-induced severe oral mucositis in children and conducted a large single-center case series.

METHODS

Ovid MEDLINE, PubMed, and Cochrane databases were searched for studies reporting IV opioid duration and/or dose requirements for severe mucositis. Secondly, our pain service database was interrogated to describe episodes of opioid administration by patient- or nurse-controlled analgesia (PCA/NCA) for children with mucositis and cancer treatment-related pain.

RESULTS

Seventeen studies (six randomized trials, two prospective observational, three retrospective cohort, six retrospective case series) included IV opioid in 618 patients (age 0.3-22.3 years), but reported parameters varied. Mucositis severity and chemotherapy indication influenced IV opioid requirements, with duration ranging from 3 to 68 days and variable dose trajectories (hourly morphine or equivalent 0-97 mcg/kg/h). Our 7-year series included PCA/NCA for 364 episodes of severe mucositis (302 patients; age 0.12-17.2 years). Duration ranged from 1 to 107 days and dose requirements in the first 3 days from 1 to 110 mcg/kg/h morphine. Longer PCA/NCA duration was associated with: higher initial morphine requirements (ρ = 0.46 [95% CI 0.35, 0.57]); subsequent increased pain and need for ketamine co-analgesia (118/364 episodes with opioid/ketamine 13.9 [9.8-22.2] days vs opioid alone 6.0 [3.9-10.8] days; median [IQR]); but not with age or sex.

CONCLUSIONS

Management of severe mucositis pain can require prolonged IV opioid therapy. Individual and treatment-related variability in analgesic requirements highlight the need for regular review, titration, and management by specialist services.

Suspected benzodiazepine withdrawal-associated seizures in 3 young dogs undergoing mechanical ventilation

OBJECTIVE

To describe new onset of generalized seizures in 3 young dogs following cessation of a benzodiazepine-containing sedation protocol to facilitate mechanical ventilation (MV) for hypoxemia.

SERIES SUMMARY

Three dogs under 5 months of age underwent MV due to severe hypoxemia. All 3 dogs were sedated with a constant rate infusion of benzodiazepines as part of their sedation protocol to facilitate MV. All 3 dogs had an acute onset of generalized seizures within 36 hours of sedation cessation and weaning from MV. All 3 dogs' seizures were successfully managed with a slow, tapering course of benzodiazepines. One dog was additionally treated with levetiracetam at the time of initial seizure activity, which was discontinued 1 year following discharge and absence of ongoing seizure activity. All 3 dogs were discharged successfully with no reports of ongoing seizures or neurologic deficits after discharge.

NEW OR UNIQUE INFORMATION PROVIDED

Young dogs managed with benzodiazepines to facilitate MV may have acute onset of generalized seizures following cessation, which can be successfully managed with short-term benzodiazepine therapy. The 3 cases in this series demonstrated a positive outcome and were successfully managed following acute onset of generalized seizure activity post-MV.

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.

Weaning Analgosedation in Patients Requiring Prolonged Mechanical Ventilation

Although research supports the minimization of sedation in mechanically ventilated patients, many patients with severe acute respiratory distress syndrome (ARDS) receive prolonged opioid and sedative infusions. ICU teams face the challenge of weaning these medications, balancing the risks of sedation with the potential to precipitate withdrawal symptoms. In this article, we use a clinical case to discuss our approach to weaning analgosedation in patients recovering from long-term mechanical ventilation. We believe that a protocolized, multimodal weaning strategy implemented by a multidisciplinary care team is required to reduce potential harm from both under- and over-sedation. At present, there is no strong randomized clinical trial evidence to support a particular weaning strategy in adult ICU patients, but appraisal of the existing literature in adults and children can guide decision-making to enhance the recovery of these patients.

Analysis of fentanyl pharmacokinetics, and its sedative effects and tolerance in critically ill children

INTRODUCTION

Fentanyl pharmacokinetic and pharmacodynamic data are limited in mechanically ventilated children. This study aimed to assess the fentanyl pharmacokinetics (PK), the sedation outcome, and the development of tolerance in children receiving fentanyl continuous infusion.

METHODS

This study included children admitted to the pediatric or cardiovascular intensive care unit between January 1 and October 31, 2016, who were >30 days to <18 years of age, receiving ventilatory support via endotracheal tube or tracheostomy, and receiving a fentanyl infusion. Population PK analysis was performed using a nonlinear mixed-effects model. The relationship between initial sedation outcome using State Behavioral Scale (SBS) and fentanyl exposure was assessed, and the observations consistent with tolerance were described.

RESULTS

Seventeen children, with a median age of 0.83 years (range: 0.1-12) and weight of 8.7 kg (range: 3.4-52), were included. The fentanyl PK was adequately described by a weight-based allometry model with the power of 0.75 for clearance (CL=89.8 L/hr/70 kg) and distributional CL, and 1 for volumes of distribution. In infants <6.6 months, age was an additional factor for CL (31.4 L/h/70 kg) to account for age-related maturation. Seven of twelve nonparalyzed patients achieved goal sedation, defined as >80% of SBS scores ≤0 per 24 h, on the first day of fentanyl infusion with a median plasma concentration of 1.29 ng/ml (interquartile range: 0.78-2.05). Eight of the nine tolerant patients developed tolerance within a day of reaching goal sedation.

CONCLUSION

Different weight-based fentanyl dosing rates may be required for infants and children of different ages to achieve similar plasma concentrations. Using SBS scores may guide the dosing titration of fentanyl that resulted in plasma concentrations within the therapeutic range of 1-3 ng/ml. For those who developed tolerance to fentanyl and/or a sedative, it was noted one day after goal sedation was achieved.

Maternal and iatrogenic neonatal opioid withdrawal syndrome: Differences and similarities in recognition, management, and consequences

Opioids are potent analgesics used to manage pain in both young and old, but the increased use in the pregnant population has significant individual and societal implications. Infants dependent on opioids, either through maternal or iatrogenic exposure, undergo neonatal opioid withdrawal syndrome (NOWS), where they may experience withdrawal symptoms ranging from mild to severe. We present a detailed and original review of NOWS caused by maternal opioid exposure (mNOWS) and iatrogenic opioid intake (iNOWS). While these two entities have been assessed entirely separately, recognition and treatment of the clinical manifestations of NOWS overlap. Neonatal risk factors such as age, genetic predisposition, drug type, and clinical factors like type of opioid, cumulative dose of opioid exposure, and disease status affect the incidence of both mNOWS and iNOWS, as well as their severity. Recognition of withdrawal is dependent on clinical assessment of symptoms, and the use of clinical assessment tools designed to determine the need for pharmacotherapy. Treatment of NOWS relies on a combination of non-pharmacological therapies and pharmacological options. Long-term consequences of opioids and NOWS continue to generate controversy, with some evidence of anatomic brain changes, but conflicting animal and human clinical evidence of significant cognitive or behavioral impacts on school-age children. We highlight the current knowledge on clinically relevant recognition, treatment, and consequences of NOWS, and identify new advances in clinical management of the neonate. This review brings a unique clinical perspective and critically analyzes gaps between the clinical problem and our preclinical understanding of NOWS.