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).
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).
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.
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.