Dexmedetomidine: A Review of Its Use for Sedation in the Intensive Care Setting

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.

Exploring Opioid-Sparing Multimodal Analgesia Options in Trauma: A Nursing Perspective

Challenges with opioids (e.g., adverse events, misuse and abuse with long-term administration) have led to a renewed emphasis on opioid-sparing multimodal management of trauma pain. To assess the extent to which currently available evidence supports the efficacy and safety of various nonopioid analgesics and techniques to manage trauma pain, a literature search of recently published references was performed. Additional citations were included on the basis of authors' knowledge of the literature. Effective options for opioid-sparing analgesics include oral and intravenous (IV) acetaminophen; nonsteroidal anti-inflammatory drugs available via multiple routes; and anticonvulsants, which are especially effective for neuropathic pain associated with trauma. Intravenous routes (e.g., IV acetaminophen, IV ketorolac) may be associated with a faster onset of action than oral routes. Additional adjuvants for the treatment of trauma pain are muscle relaxants and alpha-2 adrenergic agonists. Ketamine and regional techniques play an important role in multimodal therapy but require medical and nursing support. Nonpharmacologic treatments (e.g., cryotherapy, distraction techniques, breathing and relaxation, acupuncture) supplement pharmacologic analgesics and can be safe and easy to implement. In conclusion, opioid-sparing multimodal analgesia addresses concerns associated with high doses of opioids, and many pharmacologic and nonpharmacologic options are available to implement this strategy. Nurses play key roles in comprehensive patient assessment; administration of patient-focused, opioid-sparing, multimodal analgesia in trauma; and monitoring for safety concerns.

Clinical Assessment and Management of Delirium in the Palliative Care Setting

Delirium is a neurocognitive syndrome arising from acute global brain dysfunction, and is prevalent in up to 42% of patients admitted to palliative care inpatient units. The symptoms of delirium and its associated communicative impediment invariably generate high levels of patient and family distress. Furthermore, delirium is associated with significant patient morbidity and increased mortality in many patient populations, especially palliative care where refractory delirium is common in the dying phase. As the clinical diagnosis of delirium is frequently missed by the healthcare team, the case for regular screening is arguably very compelling. Depending on its precipitating factors, a delirium episode is often reversible, especially in the earlier stages of a life-threatening illness. Until recently, antipsychotics have played a pivotal role in delirium management, but this role now requires critical re-evaluation in light of recent research that failed to demonstrate their efficacy in mild- to moderate-severity delirium occurring in palliative care patients. Non-pharmacological strategies for the management of delirium play a fundamental role and should be optimized through the collective efforts of the whole interprofessional team. Refractory agitated delirium in the last days or weeks of life may require the use of pharmacological sedation to ameliorate the distress of patients, which is invariably juxtaposed with increasing distress of family members. Further evaluation of multicomponent strategies for delirium prevention and treatment in the palliative care patient population is urgently required.

The Benefit of Neuromuscular Blockade in Patients with Postanoxic Myoclonus Otherwise Obscuring Continuous Electroencephalography (CEEG)

Introduction. Myoclonus status epilepticus is independently associated with poor outcome in coma patients after cardiac arrest. Determining if myoclonus is of cortical origin on continuous electroencephalography (CEEG) can be difficult secondary to the muscle artifact obscuring the underlying CEEG. The use of a neuromuscular blocker can be useful in these cases. Methods. Retrospective review of CEEG in patients with postanoxic myoclonus who received cisatracurium while being monitored. Results. Twelve patients (mean age: 53.3 years; 58.3% male) met inclusion criteria of clinical postanoxic myoclonus. The initial CEEG patterns immediately prior to neuromuscular blockade showed myoclonic artifact with continuous slowing (50%), burst suppression with myoclonic artifact (41.7%), and continuous myogenic artifact obscuring CEEG (8.3%). After intravenous administration of cisatracurium (0.1 mg–2 mg), reduction in artifact improved quality of CEEG recordings in 9/12 (75%), revealing previously unrecognized patterns: continuous EEG seizures (33.3%), lateralizing slowing (16.7%), burst suppression (16.7%), generalized periodic discharges (8.3%), and, in the patient who had an initially uninterpretable CEEG from myogenic artifact, continuous slowing. Conclusion. Short-acting neuromuscular blockade is useful in determining background cerebral activity on CEEG otherwise partially or completely obscured by muscle artifact in patients with postanoxic myoclonus. Fully understanding background cerebral activity is important in prognostication and treatment, particularly when there are underlying EEG seizures.

Comparative evaluation of midazolam, dexmedetomidine, and propofol as Intensive Care Unit sedatives in postoperative electively ventilated eclamptic patients

Background and Aims:

Eclampsia is a common hypertensive disorder of pregnancy and treatment often includes termination of pregnancy with elective postoperative mechanical ventilation. The present study was aimed to compare midazolam, propofol, and dexmedetomidine for sedation and antihypertensive requirements of such patients admitted to Intensive Care Unit (ICU) after termination of pregnancy.

Material and Methods:

A total of ninety eclamptic patients administered general anesthesia for the termination of pregnancy through cesarean section and who also required postoperative ventilation were taken up for the study and were randomly allocated into three groups. All patients received MgSO4 (loading dose, 4 g intravenous) following first seizure episode followed by a continuous infusion for next 24 h. Midazolam group (GrM) received 0.05 mg/kg loading dose of midazolam, followed by infusion of 0.05–0.3 mg/kg/h, propofol group (GrP) received 1 mg/kg loading dose of propofol followed by infusion of 2–8 mg/kg/h, and dexmedetomidine group (GrD) received dexmedetomidine loading dose at 1 mcg/kg followed by infusion of 0.2–1.2 mcg/kg/h. Postoperatively, patients were assessed for hemodynamic stability, requirement of antihypertensive and analgesics, duration of sedation and stop sedation-discharge, and total time spent in the ICU.

Results:

Mean heart rate and mean arterial pressure recorded at different time intervals were lowest in GrD. Nearly 70% (n = 21) patients in the GrM required antihypertensive, 50% (n = 15) in GrP, and 36.6% (n = 11) in the GrD (P < 0.05). Duration of stop sedation-discharge from ICU was least in GrD. A number of patients demanding additional analgesics was also least in GrD.

Conclusion:

Sedation with dexmedetomidine produced better hemodynamic stability in eclamptic patients, and there was a significant reduction in requirement of additional analgesics (P = 0.035) and antihypertensive (P = 0.004). Total duration of ICU stay was also less in this group of patients.

The protective and hemodynamic effects of dexmedetomidine on hypertensive cerebral hemorrhage patients in the perioperative period

The aim of the present study was to analyze the protective and hemodynamic effects of dexmedetomidine in hypertensive cerebral hemorrhage (HCH) patients during perioperative period. In total, 50 HCH patients were selected and randomly divided into two groups, one group was administered with dexmedetomidine and the other groups with midazolam. The mean arterial pressure (MAP), heart rate (HR) and blood oxygen saturation (SpO₂) were monitored in the two groups of patients before and during the operation. The MAP, HR, SpO₂ and P_ETCO₂ recorded 5 min after admission into the operation room was considered T₁, the same parameters recorded 10 min after drug administration were considered T₂, just after starting the operation were considered T₃ and 30 min after start of operation were considered T₄. The preoperative sedation and analgesia were evaluated by the Ramsay scoring method and the neuron-specific enolase (NSE) and S100 protein (S100β) were estimated using ELISA. The patients of the midazolam group experienced mild respiratory depression during the period of sedation. Levels of, MAP, HR and P_ETCO₂ were significantly increased whereas SPO₂ was decreased (P<0.05). The MAP, HR, SPO₂ and P_ETCO₂ were stable during the period of sedation (P>0.05). The plasma concentrations of epinephrine and norepinephrine at T₁ were similar in the two groups (P>0.05), but decreased after drug administration. This decrease was more prominent in the dexmedetomidine group patients (P<0.05) than midazolam group patients. The epinephrine and norepinephrine concentrations just after starting operation (T₃) were higher than the basal level (T₁) in the midazolam group, but close to the basal level in the dexmedetomidine group (P<0.05). The serum concentration of NSE and S100β in the two groups showed no difference (P>0.05) at the end of operation (T₅), but after 24 h of operation (T₇) NSE and S100β in the dexmedetomidine group were significantly lower compared to the midazolam group (P<0.05). In conclusion, the administration of dexmedetomidine for patients with HCH during perioperative period is safe and serves as an effective sedative, without causing respiratory depression and does not influence stable haemodynamics with certain brain protective effect.

Pharmacy-Driven Dexmedetomidine Stewardship and Appropriate Use Guidelines in a Community Hospital Setting

BACKGROUND

Dexmedetomidine is a widely utilized agent in the intensive care unit (ICU) because it does not suppress respiratory drive and may be associated with less delirium than midazolam or propofol. Cost of dexmedetomidine therapy and debate as to the proper duration of use has brought its use to the forefront of discussion.

OBJECTIVE

To validate the efficacy and cost savings associated with pharmacy-driven dexmedetomidine appropriate use guidelines and stewardship in mechanically ventilated patients.

METHODS

This was a retrospective cohort study of adult patients who received dexmedetomidine for ICU sedation while on mechanical ventilation at a 433-bed not-for-profit community hospital. Included patients were divided into pre-enactment (PRE) and postenactment (POST) of dexmedetomidine guideline groups.

RESULTS

A total of 100 patients (50 PRE and 50 POST) were included in the analysis. A significant difference in duration of mechanical ventilation (11.1 vs 6.2 days, P = 0.006) and incidence of reintubation (36% vs 18% of patients, P = 0.043) was seen in the POST group. Aggregate use of dexmedetomidine 200-µg vials (37.1 vs 18.4 vials, P = 0.010) and infusion days (5.4 vs 2.5 days, P = 0.006) were significantly lower in the POST group. Dexmedetomidine acquisition cost savings were calculated at $374 456.15 in the POST group. There was no difference between the PRE and POST groups with regard to ICU length of stay, expected mortality, and observed mortality.

CONCLUSIONS

Pharmacy-driven dexmedetomidine appropriate use guidelines decreased the use of dexmedetomidine and increased cost savings at a community hospital without adversely affecting clinical outcomes.

Post-operative cardiac arrest induced by co-administration of amiodarone and dexmedetomidine: a case report

We firstly report a postoperative hemodialysis patient who was co-administered with amiodarone and dexmedetomidine and developed severe bradycardia followed by cardiac arrest. A 79-year-old male patient underwent an amputation of the right lower extremity. The electrocardiogram of the patient showed a complete right bundle branch block with left anterior fascicular block before the anesthesia, and paroxysmal atrial tachycardia over 200 beats/min lasting 15 min was observed during surgery. After admission to the intensive care unit, the intensivist and the consultant cardiologist decided to treat tachycardia using amiodarone. The initial dosing of amiodarone and the maintenance infusion succeeded to decrease the heart rate. Approximately 2 h and a half after the start of dexmedetomidine infusion for sedation, the heart rate gradually declined and severe bradycardia suddenly followed by cardiac arrest was observed. Resuscitation was promptly initiated and the patient regained sinus rhythm without delay. In retrospective analysis, the monitoring record of the electrocardiogram revealed the marked atrioventricular conduction abnormalities. This is the first case report concerning a cardiac arrest induced by amiodarone and dexmedetomidine.