Evaluating the use of dexmedetomidine in neurocritical care patients

Patient-Specific Factors Associated with Dexmedetomidine Dose Requirements in Critically Ill Children

The objective of this study was to evaluate patient-specific factors associated with dexmedetomidine dose requirements during continuous infusion. A retrospective cross-sectional analysis of electronic health record-derived data spanning 10 years for patients admitted with a primary respiratory diagnosis at a quaternary children's hospital and who received a dexmedetomidine continuous infusion (n = 346 patients) was conducted. Penalized regression was used to select demographic, clinical, and medication characteristics associated with a median daily dexmedetomidine dose. Identified characteristics were included in multivariable linear regression models and sensitivity analyses. Critically ill children had a median hourly dexmedetomidine dose of 0.5 mcg/kg/h (range: 0.1–1.8), median daily dose of 6.7 mcg/kg/d (range: 0.9–38.4), and median infusion duration of 1.6 days (range: 0.25–5.0). Of 26 variables tested, 15 were selected in the final model with days of dexmedetomidine infusion (β: 1.9; 95% confidence interval [CI]: 1.6, 2.3), median daily morphine milligram equivalents dosing (mg/kg/d) (β: 0.3; 95% CI: 0.1, 0.5), median daily ketamine dosing (mg/kg/d) (β: 0.2; 95% CI: 0.1, 0.3), male sex (β: −1.1; 95% CI: −2.0, −0.2), and non-Black reported race (β: −1.2; 95% CI: −2.3, −0.08) significantly associated with median daily dexmedetomidine dose. Approximately 56% of dose variability was explained by the model. Readily obtainable information such as demographics, concomitant medications, and duration of infusion accounts for over half the variability in dexmedetomidine dosing. Identified factors, as well as additional environmental and genetic factors, warrant investigation in future studies to inform precision dosing strategies.

Weaning from mechanical ventilation in neurocritical care

In the intensive care unit (ICU), weaning from mechanical ventilation follows a step-by-step process that has been well established in the general ICU population. However, little data is available in brain injury patients, who are often intubated to protect airways and prevent central hypoventilation. In this narrative review, we describe the general principles of weaning and how these principles can be adapted to brain injury patients. We focus on three major issues regarding weaning from mechanic ventilation in brain injury patients: (1) sedation protocol, (2) weaning and extubation protocol and criteria, (3) criteria, timing and technique for tracheostomy.

Therapeutic options for agitation in the intensive care unit

Agitation is common in the intensive care unit (ICU). There are numerous contributing factors, including pain, underlying disease, withdrawal syndrome, delirium and some medication. Agitation can compromise patient safety through accidental removal of tubes and catheters, prolong the duration of stay in the ICU, and may be related to various complications. This review aims to analyse evidence-based medical literature to improve management of agitation and to consider pharmacological strategies. The non-pharmacological approach is considered to reduce the risk of agitation. Pharmacological treatment of agitated patients is detailed and is based on a judicious choice of neuroleptics, benzodiazepines and α2 agonists, and on whether a withdrawal syndrome is identified. Specific management of agitation in elderly patients, brain-injured patients and patients with sleep deprivation are also discussed. This review proposes a practical approach for managing agitation in the ICU.

DEXmedetomidine compared to PROpofol in NEurocritical Care [DEXPRONE]: A multicenter retrospective evaluation of clinical utility and safety

PURPOSE

Although guidelines recommend dexmedetomidine (DEX) or propofol (PRO) as preferred sedatives in critically ill adults, comparisons in neurocritical care (NCC) are limited. We aimed to evaluate the clinical utility and safety of DEX compared with PRO in NCC setting.

MATERIALS AND METHODS

This retrospective, multicenter, observational cohort study conducted at three tertiary academic hospitals with Level 1 Trauma Center and Comprehensive Stroke Center designations, compared the clinical indication and safety of DEX vs PRO in patients in NCC setting.

RESULTS

179 patients were included (94 DEX and 85 PRO), median age of 58, 49% were male (DEX) and 58% were male (PRO). PRO was more commonly used to manage agitation. DEX was more commonly used for facilitating extubation, alcohol withdrawal, and sedation during frequent neurologic assessments. Mean Glasgow Coma Scale scores were higher in DEX group (11 vs. 9; p = .04). The duration of either infusions, mechanical ventilation, and lengths of stay were similar. No difference was observed in hypotension or bradycardia rates. Death was significantly higher with PRO (DEX 10% vs. PRO 22%; p = .02).

CONCLUSIONS

DEX and PRO were used for distinct indications in our cohort. Adverse effect profiles and clinical outcome, in the cohorts are largely similar.

Safety and efficacy of applying sufficient analgesia combined with a minimal sedation program as an early antihypertensive treatment for spontaneous intracerebral hemorrhage: a randomized controlled trial

Background

Spontaneous intracerebral hemorrhage (ICH) is a serious threat to human health. Although early blood pressure (BP) elevation is closely associated with a poor prognosis, the optimal antihypertensive regimen for acute-phase ICH remains controversial. In ICH, pain, sleep deprivation, and stress are usually the main causes of dramatic BP increases. While traditional antihypertensive treatment resolves the increased BP, it does not address the root cause of the disease. Remifentanil relieves pain and, when combined with dexmedetomidine’s antisympathetic action, can restore elevated BP to normal levels. Here, we seek to validate the efficacy and safety of applying sufficient analgesia in combination with a minimal sedation program versus antihypertensive drug therapy for the early and rapid stabilization of BP in ICH patients.

Methods/design

We are conducting a multicenter, prospective, randomized controlled, single-blinded, superiority clinical trial across 15 hospitals. We will enroll 354 subjects in mainland China, and all subjects will be randomized into experimental and control groups in which they will be given remifentanil combined with dexmedetomidine or antihypertensive drugs (urapidil, nicardipine, and labetalol). The primary endpoint will be the systolic BP control rate within 1 h of treatment initiation, and the efficacy and safety of the antihypertensive regimens will be compared between the two groups. Secondary endpoints include the incidence rate of early hemorrhage growth, neurological function, duration of intensive care unit (ICU) stay, and staff satisfaction with the treatment process.

Discussion

We hypothesize that applying sufficient analgesia in combination with minimal sedation will act as an effective and safe antihypertensive strategy in ICH and that this treatment strategy could, therefore, be widely used as an ICH acute-phase therapy.

Trial registration

ClinicalTrials.gov, ID: NCT03207100. Registered on 22 July 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2943-6) contains supplementary material, which is available to authorized users.

Emergency Neurological Life Support: Airway, Ventilation, and Sedation

Airway management and ventilation are central to the resuscitation of the neurologically ill. These patients often have evolving processes that threaten the airway and adequate ventilation. Furthermore, intubation, ventilation, and sedative choices directly affect brain perfusion. Therefore, Airway, Ventilation, and Sedation was chosen as an Emergency Neurological Life Support protocol. Topics include airway management, when and how to intubate with special attention to hemodynamics and preservation of cerebral blood flow, mechanical ventilation settings and the use of sedative agents based on the patient's neurological status.

Neuroprotective effect of dexmedetomidine in a murine model of traumatic brain injury

No FDA approved pharmacological therapy is available that would reduce cell death following traumatic brain injury (TBI). Dexmedetomidine (Dex) is a highly selective agonist of alpha-2 adrenergic receptors and has demonstrated neuroprotective effects in hippocampal slice cultures undergoing direct impact. However, no one has tested whether Dex, in addition to its sedative action, has neuroprotective effects in an animal model of TBI. Thus, in the present study, we investigated the effects of Dex on an animal model of TBI. Mice received different doses of Dex (1, 10, or 100 µg/kg bodyweight, n = 10 each group) or saline as control at 1 hour and 12 hours following TBI. The mice treated with Dex lost less cortical tissue than the control mice. Further analysis found that Dex treatment reduced cell death in the cortex and the hippocampus measured by Fluoro-Jade B (FJB) staining, prevented axonal degeneration detected by immunostaining with antibody against β-amyloid precursor protein (β-APP), and protected synapses from elimination with synaptophysin staining. Taken together, in an in vivo murine model of TBI, Dex at the dose of 100 µg/kg not only prevented tissue lesion and cell death, but also reduced axonal injury and synaptic degeneration caused by TBI.

Use of Dexmedetomidine in Cardiothoracic and Vascular Anesthesia

Dexmedetomidine is a highly selective α₂-adrenergic agonist with analgesic and sedative properties. In the United States, the Food and Drug Administration approved the use of the drug for short-lasting sedation (24 h) in intensive care units (ICUs) in patients undergoing mechanical ventilation and endotracheal intubation. In October 2008, the Food and Drug Administration extended use of the drug for the sedation of nonintubated patients before and during surgical and nonsurgical procedures. In the European Union, the European Medicine Agency approved the use of dexmedetomidine in September 2011 with a single recognized indication: ICU adult patients requiring mild sedation and awakening in response to verbal stimulus. At present, the use of dexmedetomidine for sedation outside the ICU remains an off-label indication. The benefits of dexmedetomidine in critically ill patients and in cardiac, electrophysiology-related, vascular, and thoracic procedures are discussed.

Use of Dexmedetomidine for Prophylactic Analgesia and Sedation in Patients With Delayed Extubation After Craniotomy: A Randomized Controlled Trial

Background:

We conducted a randomized trial to evaluate the efficacy and safety of dexmedetomidine for prophylactic analgesia and sedation in patients with delayed extubation after craniotomy.

Methods:

From June 2012 to July 2014, 150 patients with delayed extubation after craniotomy were randomized 1:1 and were assigned to the dexmedetomidine group that received a continuous infusion of 0.6 μg/kg/h (10 μg/mL) or the control group that received a maintenance infusion of 0.9% sodium chloride for injection. The mean percentage of time under optimal sedation (SAS3-4), the percentage of patients who required rescue with propofol/fentanyl, and the total dose of propofol/fentanyl required throughout the course of drug infusion, as well as VAS, HR, MAP, and SpO₂ were recorded.

Results:

The percentage of time under optimal sedation was significantly higher in the dexmedetomidine group than in the control group (98.4%±6.7% vs. 93.0%±16.2%, P=0.008). The VAS was significantly lower in the dexmedetomidine group than in the control group (1.0 vs. 4.0, P=0.000). The HR and mean BP were significantly lower in the dexmedetomidine group than in the control group at all 3 time points (before endotracheal suctioning, immediately after extubation, and 30 min after extubation). No significant difference in SpO₂ was observed between the 2 groups. For hemodynamic adverse events, patients in the dexmedetomidine group were more likely to develop bradycardia (5.3% vs. 0%, P=0.043) but had a lower likelihood of tachycardia (2.7% vs. 18.7%, P=0.002).

Conclusions:

Dexmedetomidine may be an effective prophylactic agent to induce sedation and analgesia in patients with delayed extubation after craniotomy. The use of dexmedetomidine (0.6 μg/kg/h) infusion does not produce respiratory depression, but may increase the incidence of bradycardia.

Dexmedetomidine for Refractory Intracranial Hypertension

Dexmedetomidine (DEX) is a selective α₂ adrenergic agonist that is commonly used for sedation in the intensive care unit (ICU). The role of DEX for adjunctive treatment of refractory intracranial hypertension is poorly defined. The primary objective of this study was to determine the effect of DEX on the need for rescue therapy (ie, hyperosmolar boluses, extraventricular drain [EVD] drainages) for refractory intracranial hypertension. Secondary objectives included the number of intracranial pressure (ICP) excursions, bradycardic, hypotensive, and compromised cerebral perfusion pressure episodes. This retrospective cohort study evaluated patients admitted to the neurosurgical ICU from August 1, 2009, to July 29, 2015, and who received DEX for refractory intracranial hypertension. The objectives were compared between the 2 time periods-before (pre-DEX) and during therapy (DEX). Twenty-three patients with 26 episodes of refractory intracranial hypertension met the inclusion criteria. The number of hyperosmolar boluses was decreased after DEX therapy was initiated. Mannitol boluses required were statistically reduced (1 vs 0.5, P = .03); however, reduction in hypertonic boluses was not statistically significant (1.3 vs 0.9, P = .2). The mean number of EVD drainages per 24 hours was not significantly different between the time periods (15.7 vs 14.0, P = .35). The rate of ICP excursions did not differ between the 2 groups (24.3 vs 22.5, P = .62). When compared to pre-DEX data, there was no difference in the median number of hypotensive (0 vs 0), bradycardic (0 vs 0), or compromised cerebral perfusion pressure episodes (0.5 vs 1.0). Dexmedetomidine may avoid increases in the need for rescue therapy when used as an adjunctive treatment of refractory intracranial hypertension without compromising hemodynamics.

Role of Dexmedetomidine for Sedation in Neurocritical Care Patients: A Qualitative Systematic Review and Meta-analysis of Current Evidence

INTRODUCTION

This systematic review appraises the clinical evidence on efficacy and safety of dexmedetomidine (DEX), as a sole sedative or as sedative adjunct in adult neurocritical care (NCC) patients.

MATERIALS AND METHODS

A database search was conducted to identify randomized clinical trials and observational studies reporting the use of DEX alone or as adjunct for sedation in NCC setting. The primary outcome was the occurrence of hemodynamic changes, whereas the secondary outcomes were sedative and analgesic efficacy, quality and time to awakening, and development of adverse events.

RESULTS

Eight trials including 3 randomized controlled trials and 5 observational studies, enrolling 650 patients, were selected. All the retrieved studies had a high risk of bias and a low to moderate quality. Dexmedetomidine provided a better sedation score and reduced analgesic requirements when compared to propofol or midazolam sedation. No statistically significant difference in the combined hemodynamic effect (hypotension or bradycardia) between DEX and controls (risk ratio, 1.50; 95% confidence interval, 0.65-3.48; P = 0.34; I = 56%) was identified. Adverse events were not consistently reported.

CONCLUSIONS

Available clinical literature supporting the efficacy and safety of DEX use in adult NCC setting is of limited quantity and quality. However, from the current evidence on the use of DEX in NCC, as sole sedative agent or as an adjunct, seems to be both efficient and safe.

Emergency Neurological Life Support: Airway, Ventilation, and Sedation

Airway management and ventilation are central to the resuscitation of the neurologically ill. These patients often have evolving processes that threaten the airway and adequate ventilation. Furthermore, intubation, ventilation, and sedative choices directly affect brain perfusion. Therefore, airway, ventilation, and sedation was chosen as an emergency neurological life support protocol. Topics include airway management, when and how to intubate with special attention to hemodynamics and preservation of cerebral blood flow, mechanical ventilation settings, and the use of sedative agents based on the patient's neurological status.

ICU sedation with dexmedetomidine after severe traumatic brain injury

OBJECTIVE

To comprehensively describe the use of dexmedetomidine in a single institutional series of adult ICU patients with severe TBI. This study describes the dexmedetomidine dosage and infusion times, as well as the physiological parameters, neurological status and daily narcotic requirements before, during and after dexmedetomidine infusion.

METHODS

This study identified 85 adult patients with severe TBI who received dexmedetomidine infusions in the Trauma ICU at Vanderbilt University Medical Center between 2006-2010. Demographic, haemodynamic, narcotic use and sedative use data were systematically obtained from the medical record and analysed for changes associated with dexmedetomidine infusion.

RESULTS

During infusion with dexmedetomidine, narcotic and sedative use decreased significantly (p < 0.001 and p < 0.05). Median MAP, SBP, DBP and HR also decreased significantly during infusion when compared to pre-infusion values (p < 0.001). Despite the use of dexmedetomidine, RASS and GCS scores improved from pre-infusion to infusion time periods.

CONCLUSIONS

The findings demonstrate that initiation of dexmedetomidine infusion is not associated with a decline in neurological functioning in adults with severe TBI. Although there was an observed decrease in haemodynamic parameters during infusion with dexmedetomidine, the change was not clinically significant and the requirements for narcotics and additional sedatives were minimized.

Dexmedetomidine for the treatment of alcohol withdrawal syndrome: rationale and current status of research

Dexmedetomidine is currently used in the US in the treatment of alcohol withdrawal syndrome (AWS) in the intensive care unit (ICU) setting, although data to support this practice are limited. Dexmedetomidine targets the noradrenergic system, an important but frequently overlooked secondary mechanism in the development of AWS, and, in doing so, may reduce the need for excessive benzodiazepine use which can increase the risk of γ-aminobutyric acid (GABA)-mediated deliriogenesis and respiratory depression. The purpose of this narrative review is to evaluate available literature reporting on the safety and efficacy of dexmedetomidine for AWS in the ICU setting. An English-language MEDLINE search (1966 to July 2013) was performed to identify articles evaluating the efficacy and safety of dexmedetomidine for AWS. Case series, case reports and controlled trials were evaluated for topic relevance and clinical applicability. Reference lists of articles retrieved through this search were reviewed to identify any relevant publications. Studies focusing on the safety and efficacy of dexmedetomidine for AWS in humans were selected. Studies were included if they were published as full articles; abstracts alone were not included in this review. Eight published case studies and case series were identified. Based on a limited body of evidence, dexmedetomidine shows promise as a potentially safe and possibly effective adjuvant treatment for AWS in the ICU. Prospective, well-controlled studies are needed to confirm the safety and efficacy of the use of dexmedetomidine in AWS.

[Sedation and weaning in neurocritical care: can concepts from general critical care be applied?]

The translation of modern principles of sedation and weaning from mechanical ventilation from general intensive care to neurocritical care has to take into account specific aspects of brain-injured patients. These include interactions with intracranial hypertension, disturbed autoregulation, a higher frequency of seizures and an increased risk of delirium. The advantages of sedation protocols, scoring tools to steer sedation and analgesia and an individualized choice of drugs with emphasis on analgesia gain more interest and importance in neurocritical care as well, but have not been thoroughly investigated so far. When weaning neurological intensive care unit (ICU) patients from the ventilator and approaching extubation it has to be acknowledged that conventional ICU criteria for weaning and extubation can only have an orienting character and that dysphagia is much more frequent in these patients.

Research studies that have influenced practice of neuroanesthesiology in recent years: A literature review

Through evolving research, recent years have witnessed remarkable achievements in neuromonitoring and neuroanesthetic techniques, with a huge body of literature consisting of excellent studies in neuroanaesthesiology. However, little of this work appears to be directly important to clinical practice. Many controversies still exist in care of patients with neurologic injury. This review discusses studies of great clinical importance carried out in the last five years, which have the potential of influencing our current clinical practice and also attempts to define areas in need of further research. Relevant literature was obtained through multiple sources that included professional websites, medical journals and textbooks using key words “neuroanaesthesiology,” “traumatic brain injury,” “aneurysmal subarachnoid haemorrhage,” “carotid artery disease,” “brain protection,” “glycemic management” and “neurocritical care.” In head injured patients, administration of colloid and pre-hospital hypertonic saline resuscitation have not been found beneficial while use of multimodality monitoring, individualized optimal cerebral perfusion pressure therapy, tranexamic acid and decompressive craniectomy needs further evaluation. Studies are underway for establishing cerebroprotective potential of therapeutic hypothermia. Local anaesthesia provides better neurocognitive outcome in patients undergoing carotid endarterectomy compared with general anaesthesia. In patients with aneurysmal subarachnoid haemorrhage, induced hypertension alone is currently recommended for treating suspected cerebral vasospasm in place of triple H therapy. Till date, nimodipine is the only drug with proven efficacy in preventing cerebral vasospasm. In neurocritically ill patients, intensive insulin therapy results in substantial increase in hypoglycemic episodes and mortality rate, with current emphasis on minimizing glucose variability. Results of ongoing multicentric trials are likely to further improvise our practice.

[Indications of dexmedetomidine in the current sedoanalgesia tendencies in critical patients]

Recently, dexmedetomidine has been marketed in Spain and other European countries. The published experience regarding its use has placed dexmedetomidine on current trends in sedo-analgesic strategies in the adult critically ill patient. Dexmedetomidine has sedative and analgesic properties, without respiratory depressant effects, inducing a degree of depth of sedation in which the patient can open its eyes to verbal stimulation, obey simple commands and cooperate in nursing care. It is therefore a very useful drug in patients who can be maintained on mechanical ventilation with these levels of sedation avoiding the deleterious effects of over or infrasedation. Because of its effects on α2-receptors, it's very useful for the control and prevention of tolerance and withdrawal to other sedatives and psychotropic drugs. The use of dexmedetomidine has been associated with lower incidence of delirium when compared with other sedatives. Moreover, it's a potentially useful drug for sedation of patients in non-invasive ventilation.

Emergency neurological life support: airway, ventilation, and sedation

Airway management is central to the resuscitation of the neurologically ill. These patients often have evolving processes that threaten the airway and adequate ventilation. Therefore, airway, ventilation, and sedation were chosen as an Emergency Neurological Life Support (ENLS) protocol. Reviewed topics include airway management; the decision to intubate; when and how to intubate with attention to cardiovascular status; mechanical ventilation settings; and the use of sedation, including how to select sedative agents based on the patient's neurological status.

Sedation in traumatic brain injury

Several different classes of sedative agents are used in the management of patients with traumatic brain injury (TBI). These agents are used at induction of anaesthesia, to maintain sedation, to reduce elevated intracranial pressure, to terminate seizure activity and facilitate ventilation. The intent of their use is to prevent secondary brain injury by facilitating and optimising ventilation, reducing cerebral metabolic rate and reducing intracranial pressure. There is limited evidence available as to the best choice of sedative agents in TBI, with each agent having specific advantages and disadvantages. This review discusses these agents and offers evidence-based guidance as to the appropriate context in which each agent may be used. Propofol, benzodiazepines, narcotics, barbiturates, etomidate, ketamine, and dexmedetomidine are reviewed and compared.

A critical appraisal of sedation, analgesia and delirium in neurocritical care

Administering analgesics, sedatives and antipsychotics is challenging in the Neurological Intensive Care Unit (NICU). We reviewed this literature and our current practice to better inform the critical care practitioner and to identify gaps for future research. We electronically searched observational, intervention and outcome studies addressing sedation, analgesia and delirium in the NICU, and their bibliographies. Practice patterns were assessed in three critical care units with specialized neurological care in Montreal. Bedside pain assessment tools are psychometrically validated in the neuro-critically ill but sedation and delirium tools are not. Rigorous pain and sedation assessments appear feasible; delirium screening has not been tested. Publications addressing outcomes and responses to pharmacologic treatment lack consistency, rigor or both. In daily practice, pharmacologic management varies greatly. Clearly, little information exists on analgesia, sedation and delirium in the NICU. Systematic evaluation of pain improves outcome. No evidence-based therapeutic recommendations can be proffered.

Pediatric traumatic brain injury: an update

PURPOSE OF REVIEW

The developing brain is particularly vulnerable to traumatic brain injury (TBI), leading to frequent disability or death. This article is an update of the pediatric specificities of TBI management.

RECENT FINDINGS

We review the evidences with regards to general management and therapeutic goals to prevent secondary injuries in pediatric TBI patients. Recent controversies in neurocritical care, such as multimodal neuromonitoring, hyperventilation, barbiturate coma, hypothermia, and decompressive surgery, are also highlighted.

SUMMARY

Many therapeutic modalities in pediatric TBI have a low level of evidence. Further research is needed to establish clear resuscitation goals. Universal objectives may not be suitable for all patients; intensive neuromonitoring may help in identifying individual therapeutic goals and guiding the selection of treatments.