Dexmedetomidine for neurosurgery


Dexmedetomidine
 (DEX) is a anesthetic and belongs to high selective alpha 2 adrenergic receptor (α2AR) agonist.

Dexmedetomidine has 8 times more affinity than clonidine for α-2 receptors is bringing newer concepts in anesthesia and intensive care practice. It was approved by the Food and Drug Administration (FDA) in 1999 for use in humans for short term sedation in intensive care unit. Initially used for sedation and analgesia in intensive care, its use has been extended to other various clinical situations as well as in regional anesthesia as a useful adjunct.

Metaanalysis shows evidence that Dexmedetomidine DEX as an anesthetic adjuvant during intracranial procedures leads to better perioperative hemodynamic control, less intraoperative opioid consumption, and fewer postoperative antiemetic requests 1).

A safe and acceptable analgesic/amnestic state for these procedures can be provided by the use of dexmedetomidine, with or without the addition of remifentanil 2).

Dexmedetomidine is beginning to be used more commonly outside of Europe. Personal experience, careful planning, and attention to detail are the basis for obtaining good awake craniotomy 3).

Dexmedetomidine can be used singly for sedation in awake craniotomy requiring ECoG. Individual dose ranges vary, but a bolus of 0.3 mcg kg-1 with an infusion of 0.2 mcg kg-1 min-1 is a good starting point, allowing accurate mapping of epileptic foci and subsequent resection 4).

Dexmedetomidine, with concurrent scalp block, is an effective and safe anesthetic approach for awake craniotomy. Dexmedetomidine facilitates the extension procedure complexity and duration in patients who might traditionally not be considered to be candidates for this procedure 5).

Either dexmedetomidine (DEX) or propofol (PRO) can be effectively and safely used for conscious sedation in awake craniotomy. Comparing the two, DEX produced a shorter arousal time and a higher degree of surgeon satisfaction 6).

Dexmedetomidine is safer and equally effective agent compared to propofol and midazolam for sedation of neurosurgical mechanically ventilated patients with good hemodynamic stability and extubation time as rapid as propofol. Dexmedetomidine also reduced postoperative fentanyl requirements 7).

DEX sedation for interventional pain management during procedures such as gasserian ganglion block may be useful 8).

Intravenous DEX exhibits synergism with regional anesthesia and facilitates postoperative pain control 9) 10).

Monitored anesthesia care using dexmedetomidine without loading dose for embolization of intracranial aneurysms appeared to be a safe and effective alternative to general anesthesia 11).

Dexmedetomidine is useful during intraoperative electrocorticography (ECoG) recording in epilepsy surgery as it enhances or does not alter spike rate in most of the cases, without any major adverse effects.

Dexmedetomidine is a option for treatment of acute severe baclofen withdrawal 12).

Microelectrode recordings in pediatric DBS can be preserved with a combination of dexmedetomidine and ketamine, remifentanil, and nicardipine. This preservation of MERs is particularly crucial in electrode placement in children 13).

There are few side-effects of dexmedetomidine, which should always be kept in mind before choosing the patients for its use. The various side-effects associated with dexmedetomidine include, but are not limited to hypotension, bradycardia, worsening of heart block, dry mouth, and nausea14) 15).

1) Peng K, Wu S, Liu H, Ji F. Dexmedetomidine as an anesthetic adjuvant for intracranial procedures: Meta-analysis of randomized controlled trials. J Clin Neurosci. 2014 Nov;21(11):1951-8. doi: 10.1016/j.jocn.2014.02.023. Epub 2014 Jun 25. PubMed PMID: 24974190.

2) Frost EA, Booij LH. Anesthesia in the patient for awake craniotomy. Curr Opin Anaesthesiol. 2007 Aug;20(4):331-5. Review. PubMed PMID: 17620841.
3) Piccioni F, Fanzio M. Management of anesthesia in awake craniotomy. Minerva Anestesiol. 2008 Jul-Aug;74(7-8):393-408. Review. PubMed PMID: 18612268.
4) Souter MJ, Rozet I, Ojemann JG, Souter KJ, Holmes MD, Lee L, Lam AM. Dexmedetomidine sedation during awake craniotomy for seizure resection: effects on electrocorticography. J Neurosurg Anesthesiol. 2007 Jan;19(1):38-44. PubMed PMID: 17198099.
5) Garavaglia MM, Das S, Cusimano MD, Crescini C, Mazer CD, Hare GM, Rigamonti A. Anesthetic approach to high-risk patients and prolonged awake craniotomy using dexmedetomidine and scalp block. J Neurosurg Anesthesiol. 2014 Jul;26(3):226-33. doi: 10.1097/ANA.0b013e3182a58aba. PubMed PMID: 24064713.
6) Shen SL, Zheng JY, Zhang J, Wang WY, Jin T, Zhu J, Zhang Q. Comparison of dexmedetomidine and propofol for conscious sedation in awake craniotomy: a prospective, double-blind, randomized, and controlled clinical trial. Ann Pharmacother. 2013 Nov;47(11):1391-9. doi: 10.1177/1060028013504082. Epub 2013 Nov 5. PubMed PMID: 24259599.
7) Srivastava VK, Agrawal S, Kumar S, Mishra A, Sharma S, Kumar R. Comparison of dexmedetomidine, propofol and midazolam for short-term sedation in postoperatively mechanically ventilated neurosurgical patients. J Clin Diagn Res. 2014 Sep;8(9):GC04-7. doi: 10.7860/JCDR/2014/8797.4817. Epub 2014 Sep 20. PubMed PMID: 25386451; PubMed Central PMCID: PMC4225903.
8) Kido H, Komasawa N, Fujiwara S, Hyoda A, Morimoto K, Minami T. [Gasserian ganglion block for trigeminal neuralgia under dexmedetomidine sedation]. Masui. 2014 Aug;63(8):901-3. Japanese. PubMed PMID: 25199328.
9) Adams R, Brown GT, Davidson M, Fisher E, Mathisen J, et al. (2013) Efficacy of dexmedetomidine compared with midazolam for sedation in adult intensive care patients: a systematic review. British journal of anaesthesia 111: 703–710
10) Abdallah FW, Abrishami A, Brull R (2013) The facilitatory effects of intravenous dexmedetomidine on the duration of spinal anesthesia: a systematic review and meta-analysis. Anesthesia and analgesia 117: 271–278
11) Lee HH, Jung YJ, Choi BY, Chang CH. Usefulness of Dexmedetomidine during Intracerebral Aneurysm Coiling. J Korean Neurosurg Soc. 2014 Apr;55(4):185-9. doi: 10.3340/jkns.2014.55.4.185. Epub 2014 Apr 30. PubMed PMID: 25024820; PubMed Central PMCID: PMC4094741.
12) Morr S, Heard CM, Li V, Reynolds RM. Dexmedetomidine for Acute Baclofen Withdrawal. Neurocrit Care. 2014 Nov 18. [Epub ahead of print] PubMed PMID: 25403764.
13) Hippard HK, Watcha M, Stocco AJ, Curry D. Preservation of microelectrode recordings with non-GABAergic drugs during deep brain stimulator placement in children. J Neurosurg Pediatr. 2014 Sep;14(3):279-86. doi: 10.3171/2014.5.PEDS13103. Epub 2014 Jul 4. PubMed PMID: 24995822.
14) Bajwa S, Kulshrestha A. Dexmedetomidine: an adjuvant making large inroads into clinical practice. Ann Med Health Sci Res. 2013 Oct;3(4):475-83. doi: 10.4103/2141-9248.122044. Review. PubMed PMID: 24379995; PubMed Central PMCID: PMC3868110.
15) Sakaguchi Y, Takahashi S. [Dexmedetomidine]. Masui. 2006 Jul;55(7):856-63.Review. Japanese. PubMed PMID: 16856546.

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