Dexmedetomidine


Article Author:
Bradley Reel


Article Editor:
Christopher Maani


Editors In Chief:
Anantha Padmanabhan
Aakash Gajjar
Burt Cagir


Managing Editors:
Avais Raja
Orawan Chaigasame
Carrie Smith
Abdul Waheed
Khalid Alsayouri
Frank Smeeks
Kristina Soman-Faulkner
Trevor Nezwek
Radia Jamil
Patrick Le
Sobhan Daneshfar
Anoosh Zafar Gondal
Saad Nazir
William Gossman
Pritesh Sheth
Hassam Zulfiqar
Navid Mahabadi
Steve Bhimji
John Shell
Matthew Varacallo
Heba Mahdy
Ahmad Malik
Mark Pellegrini
James Hughes
Beata Beatty
Nazia Sadiq
Hajira Basit
Phillip Hynes
Tehmina Warsi


Updated:
6/18/2019 2:22:23 AM

Indications

The FDA-approved indications for dexmedetomidine are sedation of intubated and mechanically ventilated patients in the intensive care unit (ICU), and peri-procedural (or peri-operative) sedation of non-intubated patients. Over time, usage has expanded to off-label uses including treatment and prevention of delirium, adjunctive analgesia, therapy for insomnia in the ICU, and treatment of alcohol withdraw. This is because it commonly produces a sedated state allowing patients to be both comfortable and cooperative during mechanical ventilation. Additionally, it does not require stoppage to accomplish extubation and is safe to use in non-intubated patients. This is because it does not produce significant respiratory depression. Given inherent analgesic properties which are rare to most sedatives, dexmedetomidine produces an opioid-sparing effect.[1]

ICU sedation with dexmedetomidine has been shown to decrease the incidence and duration of delirium, as well as delay the onset of delirium when compared with other sedatives.[2] Evidence also exists that in patients with delirium, the time to extubation and the number of ventilator-dependent hours is reduced.[3] This may be related to the ability of dexmedetomidine to reduce the need for other medications (for examples, propofol, benzodiazepines, opioids) to promote a comfortable/cooperative patient. This effect has been particularly useful in the treatment of elderly post-cardiac surgery patients.[4] The beneficial effects in this particular patient population extend into longer outcomes, including survival at 2 years and improved cognitive function and quality of life. It has also become common to treat poor sleep in the ICU with dexmedetomidine infusions at doses as high as 1.5 mcg/kg per hr. This practice is supported by research showing dexmedetomidine often yields sleep quality closely related to stage 2 non-REM sleep.[5] However, it is also important to note that there is data showing that normal sleep patterns are altered, and no restorative rapid-eye-movement or slow-wave sleep is achieved. Additionally, studies demonstrating benefit in clinical outcomes related to improved sleep generated by dexmedetomidine are sparse.[6]

Dexmedetomidine is commonly used in anesthesia practice as well. It is used for procedural sedation for a variety of operations. It is also used frequently for sedation during the performance of awake intubation. It is ideally suited for this indication for the reasons stated above. Dexmedetomidine is also used as an adjunct infusion during general anesthesia. There is evidence that dexmedetomidine decreases postoperative pain, postoperative opioid usage, and nausea.[7] This effect has also been shown to be present when dexmedetomidine is used for sedation during procedures performed under spinal anesthesia.[8] However, at least one recent study has called into question this opioid-sparing effect for a cohort of patients undergoing major spine surgery.[9] There has been interest in using dexmedetomidine as an adjunct to prevent emergence agitation, post-operative delirium, and postoperative cognitive dysfunction. There is evidence for prevention of emergence agitation in both children and adults.[10] [11]Because of enthusiasm over apparent prevention/treatment of delirium with dexmedetomidine when used for ICU sedation, it was hoped this benefit would be reproduced for postoperative delirium if an intraoperative infusion of dexmedetomidine was used; however, a recent randomized trial did not show a statistically significant benefit in this post-operative population.[12] Dexmedetomidine has also been used in peripheral nerve blocks to prolong the duration of analgesia. Research suggests the dexmedetomidine may prolong the duration of a peripheral nerve block for approximately 3 hours.[13]

Mechanism of Action

Dexmedetomidine is an alpha agonist having sedative, anxiolytic, hypnotic, analgesic, and sympatholytic properties. It produces these effects by inhibition of central sympathetic outflow by blocking the alpha receptors in the brainstem, thereby inhibiting the release of norepinephrine. It has a selectivity of 1600:1 for the alpha2 receptor as compared to alpha1. This is especially significant when comparing this to another alpha agonist, clonidine, with a selectivity of 220:1. The mechanism by which dexmedetomidine may increase the duration of a peripheral nerve block is not fully understood but is believed to most likely be a perineural mechanism rather than a systemic or central mechanism. It is thought to prolong the duration by blocking the cation current.[14]

Administration

For ICU sedation, the typical dosage range is 0.2 to 0.7 mcg/kg per hour. However, the dose can be increased to 1.5 mcg/kg per hour to achieve the desired sedation level. Doses as high as 2.5 mcg/kg per hour have been described, but it is unlikely that doses higher than 1.5 mcg/kg per hour achieve any further therapeutic benefit in the absence of increased side effects. Dosage adjustments for renal or hepatic impairment are not required but should be considered, especially for hepatic impairment. The manufacturer does not recommend durations longer than 24 hours; however, longer durations have been shown to be safe and effective. A loading dose of 0.5 to 1.0 mcg/kg can be administered. It is usually avoided if the medication is to be used for labile critically ill patients or those with tenuous hemodynamics.

When used in anesthesia, a loading dose of 0.5 to 1.0 mcg/kg is usually followed by continuous infusion of 0.2 to 0.7 mcg/kg per hour titrated to desired sedation goals. As mentioned, higher infusion doses can be used to achieve the desired effect.

When used as an adjunct for peripheral nerve block the dose of dexmedetomidine is usually 1 mcg/kg to achieve the desired prolongation.[15]

Adverse Effects

The most common adverse effects of dexmedetomidine are hypotension, bradycardia, and hypertension. Hypertension is produced by stimulation of alpha subtypes of receptors in vascular smooth muscles. Hypertension usually does not require treatment and can be avoided by the slow administration or omission of the loading dose. Hypotension and bradycardia are produced by stimulation of presynaptic alpha receptors, which leads to a decreased release of norepinephrine; this is in addition to the decrease in the central sympathetic outflow. These are concerns regardless of the route of administration.[16]

Contraindications

There are no absolute contraindications to use of dexmedetomidine. However, it should be used cautiously in patients with bradycardia and hypotension as the medication may exacerbate these findings. Additionally, it should be used cautiously in patients with known heart failure as there is level B evidence showing dexmedetomidine can potentially exacerbate myocardial dysfunction.

Monitoring

There are no specific drug monitoring requirements. The level of sedation, heart rate/rhythm, blood pressure, and pulse oximetry should be monitored closely.

Toxicity

At present, there is no chemical reversal or antidote for dexmedetomidine. Supportive care and close monitoring are the staples of treatment for overdose.


Interested in Participating?

We are looking for contributors to author, edit, and peer review our vast library of review articles and multiple choice questions. In as little as 2-3 hours you can make a significant contribution to your specialty. In return for a small amount of your time, you will receive free access to all content and you will be published as an author or editor in eBooks, apps, online CME/CE activities, and an online Learning Management System for students, teachers, and program directors that allows access to review materials in over 500 specialties.

Improve Content - Become an Author or Editor

This is an academic project designed to provide inexpensive peer-reviewed Apps, eBooks, and very soon an online CME/CE system to help students identify weaknesses and improve knowledge. We would like you to consider being an author or editor. Please click here to learn more. Thank you for you for your interest, the StatPearls Publishing Editorial Team.

Dexmedetomidine - Questions

Take a quiz of the questions on this article.

Take Quiz
Dexmedetomidine acts on what receptor?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
Which of the following side effects is not associated with dexmedetomidine?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
How does dexmedetomidine cause hypertension?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
What is the maximum dose of a dexmedetomidine infusion?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
What is the beneficial effects of dexmedetomidine on delirium?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
What evidence supports the use of dexmedetomidine as an adjunctive medication for patients undergoing surgery with general anesthesia?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
An 80-year-old female is in the intensive care unit (ICU) on postoperative day 2 after aortic valve replacement. She was extubated 4 hours after completion of surgery. Her hemodynamics, renal function, and hepatic function are normal. Her electrolytes are within normal limits. Her invasive lines have been removed. However, she appears to be delirious based on periodic agitation and inattention, particularly late in the evening. You believe this to be related to poor sleep from the prior 2 nights. You choose to use dexmedetomidine infusion to a maximum of 1.5 mcg/kg/hr to control agitation and to induce sleep. Which of following is correct in regards to the use of dexmedetomidine for insomnia in the ICU?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
A 50-year-old male with a past medical history of obstructive sleep apnea, hypertension, and hyperlipidemia is scheduled to undergo a laparoscopic sigmoidectomy for recurrent diverticulitis. The anesthesia provider is considering using dexmedetomidine as an adjunctive medication to a volatile anesthetic. What is the unique property of dexmedetomidine when compared with other sedative medications that make this a logical choice?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
A 68-year-old female is scheduled for right carotid endarterectomy. She has a history of a difficult airway, and awake fiberoptic intubation is planned. The patient’s preoperative blood pressure is 145/85 mmHg. The patient is given a bolus of 1 mcg/kg of dexmedetomidine over 5 minutes in preparation for the intubation. Just before intubation the patient’s blood pressure is noted to be 180/100 mmHg. The patient denies anxiety and is cooperative. What is a potential mechanism of hypertension in this patient?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
An 18-year-old male with severe acute respiratory distress syndrome due to influenza requires venovenous Extracorporeal membrane oxygenation (ECMO) for refractory hypoxemia and hypercarbia. The intensive care unit team wishes to have a cooperative patient that is not completely sedated. They elect to trial dexmedetomidine for sedation and analgesia. Despite a dose of 0.7 mcg/kg/hr, the patient is agitated, tachycardic, and hypertensive. The resident elects to continue to increase the dose of dexmedetomidine. What is the maximum dose of a dexmedetomidine infusion?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
A 72-year-old male is undergoing a 3-vessel coronary artery bypass grafting for severe three-vessel coronary artery disease. The intensivist asked the anesthesia team if they planned to use dexmedetomidine at any point during the anesthesia care to prevent intensive care unit delirium in this elderly patient? Which is an appropriate answer to the intensivist’s question?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up

Dexmedetomidine - References

References

Dexmedetomidine and delirium in the ICU., McLaughlin M,Marik PE,, Annals of translational medicine, 2016 Jun     [PubMed]
Dexmedetomidine versus Propofol Sedation Reduces Delirium after Cardiac Surgery: A Randomized Controlled Trial., Djaiani G,Silverton N,Fedorko L,Carroll J,Styra R,Rao V,Katznelson R,, Anesthesiology, 2016 Feb     [PubMed]
Reade MC,Eastwood GM,Bellomo R,Bailey M,Bersten A,Cheung B,Davies A,Delaney A,Ghosh A,van Haren F,Harley N,Knight D,McGuiness S,Mulder J,O'Donoghue S,Simpson N,Young P, Effect of Dexmedetomidine Added to Standard Care on Ventilator-Free Time in Patients With Agitated Delirium: A Randomized Clinical Trial. JAMA. 2016 Apr 12     [PubMed]
Zhang DF,Su X,Meng ZT,Li HL,Wang DX,Li XY,Maze M,Ma D, Impact of Dexmedetomidine on Long-term Outcomes After Noncardiac Surgery in Elderly: 3-Year Follow-up of a Randomized Controlled Trial. Annals of surgery. 2018 May 8     [PubMed]
Alexopoulou C,Kondili E,Diamantaki E,Psarologakis C,Kokkini S,Bolaki M,Georgopoulos D, Effects of dexmedetomidine on sleep quality in critically ill patients: a pilot study. Anesthesiology. 2014 Oct     [PubMed]
Goucher Miranda H,Krystal AD,Fierro MA, Nocturnal Dexmedetomidine in Nonintubated, Critically Ill Patients: Sleep or Sedation? Anesthesiology. 2017 Aug     [PubMed]
Blaudszun G,Lysakowski C,Elia N,Tramèr MR, Effect of perioperative systemic α2 agonists on postoperative morphine consumption and pain intensity: systematic review and meta-analysis of randomized controlled trials. Anesthesiology. 2012 Jun     [PubMed]
Chan IA,Maslany JG,Gorman KJ,O'Brien JM,McKay WP, Dexmedetomidine during total knee arthroplasty performed under spinal anesthesia decreases opioid use: a randomized-controlled trial. Canadian journal of anaesthesia = Journal canadien d'anesthesie. 2016 May     [PubMed]
    [PubMed]
    [PubMed]
    [PubMed]
    [PubMed]
    [PubMed]
    [PubMed]
    [PubMed]
    [PubMed]

Disclaimer

The intent of StatPearls is to provide practice questions and explanations to assist you in identifying and resolving knowledge deficits. These questions and explanations are not intended to be a source of the knowledge base of all of medicine, nor is it intended to be a board or certification review of Surgery-Colon and Rectal. The authors or editors do not warrant the information is complete or accurate. The reader is encouraged to verify each answer and explanation in several references. All drug indications and dosages should be verified before administration.

StatPearls offers the most comprehensive database of free multiple-choice questions with explanations and short review chapters ever developed. This system helps physicians, medical students, dentists, nurses, pharmacists, and allied health professionals identify education deficits and learn new concepts. StatPearls is not a board or certification review system for Surgery-Colon and Rectal, it is a learning system that you can use to help improve your knowledge base of medicine for life-long learning. StatPearls will help you identify your weaknesses so that when you are ready to study for a board or certification exam in Surgery-Colon and Rectal, you will already be prepared.

Our content is updated continuously through a multi-step peer review process that will help you be prepared and review for a thorough knowledge of Surgery-Colon and Rectal. When it is time for the Surgery-Colon and Rectal board and certification exam, you will already be ready. Besides online study quizzes, we also publish our peer-reviewed content in eBooks and mobile Apps. We also offer inexpensive CME/CE, so our content can be used to attain education credits while you study Surgery-Colon and Rectal.