Hemodynamic Effects of Preoperative Dexmedetomidine use in Older Adults

Preoperative anxiety is a common problem for patients undergoing general anesthesia and can create untoward hemodynamic effects for patients in the operating room. Dexmedetomidine is an Alpha-2 adrenergic agonist commonly used for sedation by continuous infusion. Dexmedetomidine is now used for preoperative anxiolysis, however, there are no clinical recommendations for dosing and appropriate patient selection. Due to the hemodynamics of the medication, administration can result in the adverse effects of hypotension and bradycardia.
The Quality Improvement project consisted of a retrospective chart review of 100 patients. 50 patients were aged 65-85 at a large urban trauma center and 50 patients were aged 45-64 at a smaller affiliate site. The dose of dexmedetomidine ranged from 4 to 20 micrograms.
At both sites, heart rate change was not significantly associated with age, ASA status, or dexmedetomidine dose. Blood pressure change was not significantly associated with age, ASA, or dexmedetomidine dose.
This project found that in patients aged 46-85 at both sites doses of 4-20mcg for anxiolysis did not commonly result in bradycardia or hypotension. This suggests that it is safe to administer small doses of dexmedetomidine up to 20 mcg without the need for vasopressor support to lessen preoperative anxiety.