Incidence of Dexmedetomidine Withdrawal in Adult Critically Ill Patients: A Pilot Study

Alpha2 Agonist Use in Critically Ill Adults: A Focus on Sedation and Withdrawal Prevention

The management of sedation in critically ill adults poses a unique challenge to clinicians. Dexmedetomidine, an α2 agonist, has a unique mechanism and favorable pharmacokinetics, making it an attractive intravenous option for sedation and delirium in the intensive care unit. However, patients may be at risk for withdrawal with prolonged use, adding to the complexity of sedation and agitation management in this patient population. Enteral α2 agents have the benefit of cost savings and ease of administration, thus playing a role in the ability to decrease intravenous sedative use and prevent dexmedetomidine withdrawal. Clonidine and guanfacine are the two most common enteral α2 agents utilized for this purpose, however, there is a paucity of evidence regarding the comparative benefit between the two agents. The decision to use one vs the other agent should be determined based on their differing pharmacology, pharmacokinetics, and side effect profile. The most effective dosing strategy for these agents is also unknown. Ultimately, more robust literature is required to determine enteral α2 agonists place in therapy. This narrative review evaluates the currently available literature on the use of α2 agonists in critically ill adults with an emphasis on sedation, delirium, and withdrawal.

Optimal strategies for assessing and managing pain, agitation, and delirium in the critically ill surgical patient: What you need to know

ABSTRACT

Pain, agitation, and delirium (PAD) are primary drivers of outcome in the ICU, and expertise in managing these entities successfully is crucial to the intensivist's toolbox. In addition, there are unique aspects of surgical patients that impact assessment and management of PAD. In this review, we address the continuous spectrum of assessment, and management of critically ill surgical patients, with a focus on limiting PAD, particularly incorporating mobility as an anchor to ICU liberation. Finally, we touch on the impact of PAD in specific populations, including opioid use disorder, traumatic brain injury, pregnancy, obesity, alcohol withdrawal, and geriatric patients. The goal of the review is to provide rapid access to information regarding PAD and tools to assess and manage these important elements of critical care of surgical patients.

Clonidine use during dexmedetomidine weaning: A systematic review

BACKGROUND

Dexmedetomidine is a centrally acting alpha-2A adrenergic agonist that is commonly used as a sedative and anxiolytic in the intensive care unit (ICU), with prolonged use increasing risk of withdrawal symptoms upon sudden discontinuation. As clonidine is an enterally available alpha-2A adrenergic agonist, it may be a suitable agent to taper off dexmedetomidine and reduce withdrawal syndromes. The appropriate dosing and conversion strategies for using enteral clonidine in this context are not known. The objective of this systematic review is to summarize the evidence of enteral clonidine application during dexmedetomidine weaning for prevention of withdrawal symptoms.

AIM

To systematically review the practice, dosing schema, and outcomes of enteral clonidine use during dexmedetomidine weaning in critically ill adults.

METHODS

This was a systematic review of enteral clonidine used during dexmedetomidine weaning in critically ill adults (≥ 18 years). Randomized controlled trials, prospective cohorts, and retrospective cohorts evaluating the use of clonidine to wean patients from dexmedetomidine in the critically ill were included. The primary outcomes of interest were dosing and titration schema of enteral clonidine and dexmedetomidine and risk factors for dexmedetomidine withdrawal. Other secondary outcomes included prevalence of adverse events associated with enteral clonidine use, re-initiation of dexmedetomidine, duration of mechanical ventilation, and ICU length of stay.

RESULTS

A total of 3427 studies were screened for inclusion with three meeting inclusion criteria with a total of 88 patients. All three studies were observational, two being prospective and one retrospective. In all included studies, the choice to start enteral clonidine to wean off dexmedetomidine was made at the discretion of the physician. Weaning time ranged from 13 to 167 h on average. Enteral clonidine was started in the prospective studies in a similar protocolized method, with 0.3 mg every 6 h. After starting clonidine, patients remained on dexmedetomidine for a median of 1-28 h. Following the termination of dexmedetomidine, two trials tapered enteral clonidine by increasing the interval every 24 h from 6 h to 8h, 12h, and 24 h, followed by clonidine discontinuation. For indicators of enteral clonidine withdrawal, the previously tolerable dosage was reinstated for several days before resuming the taper on the same protocol. The adverse events associated with enteral clonidine use were higher than patients on dexmedetomidine taper alone with increased agitation. The re-initiation of dexmedetomidine was not documented in any study. Only 17 (37%) patients were mechanically ventilated with median duration of 3.5 d for 13 patients in one of the 2 studies. ICU lengths of stay were similar.

CONCLUSION

Enteral clonidine is a strategy to wean critically ill patients from dexmedetomidine. There is an association of increased withdrawal symptoms and agitation with the use of a clonidine taper.

Could dexmedetomidine be repurposed as a glymphatic enhancer?

Cerebrospinal fluid (CSF) flows through the central nervous system (CNS) via the glymphatic pathway to clear the interstitium of metabolic waste. In preclinical studies, glymphatic fluid flow rate increases with low central noradrenergic tone and slow-wave activity during natural sleep and general anesthesia. By contrast, sleep deprivation reduces glymphatic clearance and leads to intracerebral accumulation of metabolic waste, suggesting an underlying mechanism linking sleep disturbances with neurodegenerative diseases. The selective α₂-adrenergic agonist dexmedetomidine is a sedative drug that induces slow waves in the electroencephalogram, suppresses central noradrenergic tone, and preserves glymphatic outflow. As recently developed dexmedetomidine formulations enable self-administration, we suggest that dexmedetomidine could serve as a sedative-hypnotic drug to enhance clearance of harmful waste from the brain of those vulnerable to neurodegeneration.

How to Manage Withdrawal of Sedation and Analgesia in Mechanically Ventilated COVID-19 Patients?

COVID-19 patients suffering from severe acute respiratory distress syndrome (ARDS) require mechanical ventilation (MV) for respiratory failure. To achieve these ventilatory goals, it has been observed that COVID-19 patients in particular require high regimens and prolonged use of sedatives, analgesics and neuromuscular blocking agents (NMBA). Withdrawal from analgo-sedation may induce a "drug withdrawal syndrome" (DWS), i.e., clinical symptoms of anxiety, tremor, agitation, hallucinations and vomiting, as a result of adrenergic activation and hyperalgesia. We describe the epidemiology, mechanisms leading to this syndrome and our strategies to prevent and treat it.

Delirium in neurosurgery: a systematic review and meta-analysis

Delirium is a frequent occurring complication in surgical patients. Nevertheless, a scientific work-up of the clinical relevance of delirium after intracranial surgery is lacking. We conducted a systematic review (CRD42020166656) to evaluate the current diagnostic work-up, incidence, risk factors and health outcomes of delirium in this population. Five databases (Embase, Medline, Web of Science, PsycINFO, Cochrane Central) were searched from inception through March 31st, 2021. Twenty-four studies (5589 patients) were included for qualitative analysis and twenty-one studies for quantitative analysis (5083 patients). Validated delirium screening tools were used in 70% of the studies, consisting of the Confusion Assessment Method (intensive care unit) (45%), Delirium Observation Screening Scale (5%), Intensive Care Delirium Screening Checklist (10%), Neelon and Champagne Confusion Scale (5%) and Nursing Delirium Screening Scale (5%). Incidence of post-operative delirium after intracranial surgery was 19%, ranging from 12 to 26% caused by variation in clinical features and delirium assessment methods. Meta-regression for age and gender did not show a correlation with delirium. We present an overview of risk factors and health outcomes associated with the onset of delirium. Our review highlights the need of future research on delirium in neurosurgery, which should focus on optimizing diagnosis and assessing prognostic significance and management.

A Clinician's Guide to Dosing Analgesics, Anticonvulsants, and Psychotropic Medications in Continuous Renal Replacement Therapy

Acute kidney injury (AKI) requiring continuous renal replacement therapy (CRRT) is a common complication in critical illness and has a significant impact on pharmacokinetic factors determining drug exposure, including absorption, distribution, transport, metabolism, and clearance. In this review, we provide a practical guide to drug dosing considerations in critically ill patients undergoing CRRT, focusing on the most commonly used analgesic, anticonvulsant, and psychotropic medications in the clinical care of critically ill patients. A literature search was conducted to identify articles in which drug dosing was evaluated in adult patients receiving CRRT between the years 1980 and 2020. We included articles with pharmacokinetic/pharmacodynamic analyses and those that described medication clearance via CRRT. A summary of the data focused on practical pharmacokinetic and pharmacodynamic principles is presented, with recommendations for drug dosing of analgesics, anticonvulsants, and psychotropic medications. Pharmacokinetic and pharmacodynamic studies to guide drug dosing of analgesics, anticonvulsants, and psychotropic medications in critically ill patients receiving CRRT are sparse. Considering the widespread use of these medications, narrow therapeutic index of these drug classes, and risks of over- and underdosing, additional studies in patients receiving CRRT are needed to inform drug dosing.

Dexmedetomidine, Delirium, and Adverse Outcomes: Analysis of the STS Adult Cardiac Surgery Database

BACKGROUND

We tested the hypothesis that dexmedetomidine was associated with a reduced incidence of postoperative delirium (POD) and adverse outcomes in cardiac surgery patients from the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database (ACSD) including the Adult Cardiac Anesthesiology subsection.

METHODS

We identified 55905 patients in the STS ACSD who underwent cardiac surgery between July 2014 and December 2018. Using propensity score weighted regression analysis, we analyzed the effect of intraoperative dexmedetomidine (intraDex) on the primary (POD) and secondary outcomes (highest pain score on day 3 and at discharge, stroke, prolonged ventilation, postoperative intubation/reintubation, additional postoperative hours ventilated, renal failure, atrial fibrillation, and 30-day mortality). In separate propensity score weighted analyses, we examined the effect of postoperative dexmedetomidine (postopDex) on the highest postoperative pain score at discharge and 30-day mortality.

RESULTS

The rate of intraDex use was 25.5% (n=13963), and its administration was associated with increased odds for POD (odds ratio [OR], 1.85; 95% CI, 1.60-2.13), a small higher average pain score on day 3 (difference in mean [MD], 0.08; 95% CI, 0.02 to 0.14), increased odds for postoperative intubation/reintubation (OR, 1.29; 95% CI, 1.12-1.48), and a small lower average pain score at discharge (MD, -0.31; 95% CI, -0.21 to -0.41). PostDex was associated with a small higher average pain score at discharge (MD, 0.27, 95% CI, 0.21 to 0.34), and higher odds for 30-day mortality (OR, 1.25, 95% CI, 1.07-1.46).

CONCLUSIONS

In this registry of cardiac surgical patients dexmedetomidine administration was associated with POD and adverse outcomes.

Evaluation of an Enteral Clonidine Taper following Prolonged Dexmedetomidine Exposure in Critically Ill Children

The aim of the current study is to evaluate the use of an enteral clonidine transition for the prevention or management of dexmedetomidine withdrawal symptoms in critically ill children not exposed to other continuous infusion sedative agents. A retrospective, single-center study was conducted in patients ≤ 18 years of age admitted to the pediatric intensive care unit who received a continuous infusion of dexmedetomidine for ≥ 24 hours and who were prescribed enteral clonidine within 72 hours of dexmedetomidine discontinuation. Predefined withdrawal terminology was established to assess for hypertension, tachycardia, agitation, tremors, and decreased sleep. A total of 105 patients were included and received enteral clonidine for prevention or management of dexmedetomidine withdrawal symptoms, with 13 patients (12.4%) requiring a taper modification to manage withdrawal symptoms. The median duration of dexmedetomidine infusion was 120.5 hours (95.5, 143.5) and median peak infusion rate was 1 µg/kg/h (1, 1.2). A higher cumulative dexmedetomidine dose of 119.2 µg/kg (96.6, 154.9) and duration of 142.9 hours (122.6, 158.3) were noted in patients who required a taper modification. Risk factors for dexmedetomidine withdrawal such as dexmedetomidine duration and cumulative dose may help predict patients at the highest risk of withdrawal that would benefit from an enteral clonidine taper to prevent dexmedetomidine withdrawal symptoms. An enteral clonidine taper can be effective in the prevention and management of dexmedetomidine withdrawal symptoms.

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

OBJECTIVES

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

DESIGN

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

SETTING

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

PATIENTS

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

INTERVENTIONS

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

MEASUREMENTS AND MAIN RESULTS

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

CONCLUSIONS

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

Sedation, Analgesia, and Paralysis in COVID-19 Patients in the Setting of Drug Shortages

The rapid spread of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has led to a global pandemic. The 2019 coronavirus disease (COVID-19) presents with a spectrum of symptoms ranging from mild to critical illness requiring intensive care unit (ICU) admission. Acute respiratory distress syndrome is a major complication in patients with severe COVID-19 disease. Currently, there are no recognized pharmacological therapies for COVID-19. However, a large number of COVID-19 patients require respiratory support, with a high percentage requiring invasive ventilation. The rapid spread of the infection has led to a surge in the rate of hospitalizations and ICU admissions, which created a challenge to public health, research, and medical communities. The high demand for several therapies, including sedatives, analgesics, and paralytics, that are often utilized in the care of COVID-19 patients requiring mechanical ventilation, has created pressure on the supply chain resulting in shortages in these critical medications. This has led clinicians to develop conservation strategies and explore alternative therapies for sedation, analgesia, and paralysis in COVID-19 patients. Several of these alternative approaches have demonstrated acceptable levels of sedation, analgesia, and paralysis in different settings but they are not commonly used in the ICU. Additionally, they have unique pharmaceutical properties, limitations, and adverse effects. This narrative review summarizes the literature on alternative drug therapies for the management of sedation, analgesia, and paralysis in COVID-19 patients. Also, this document serves as a resource for clinicians in current and future respiratory illness pandemics in the setting of drug shortages.