Low-Dose Dexmedetomidine Reduces Postoperative Delirium in Older Patients

A low dose of dexmedetomidine may reduce the incidence of postoperative delirium in older adults.
A low dose of dexmedetomidine may reduce the incidence of postoperative delirium in older adults.

In a randomized, double-blind, placebo-controlled trial published in The Lancet, a prophylactic low dose of dexmedetomidine was found to reduce the incidence of delirium in older adults following surgery.1

Postoperative delirium is the top surgical complication in elderly patients, affecting approximately 5% to 50% of individuals in this age group who undergo an operation.2 Older adults are particularly vulnerable to the consequences of delirium, which can include a multitude of negative effects such as additional postoperative complications, longer hospital stays, loss of independence and cognitive function, and death. Additionally, it is estimated that delirium results in an annual cost of $150 billion in the United States.

Adults aged 65 and older comprise more than one-third of inpatient operations in the United States, further underscoring the importance of identifying preventive solutions to this problem. Since delirium is preventable in up to 40% of cases, it “is an ideal candidate for preventive interventions targeted to improve the outcomes of older adults in the perioperative setting,” according to a best practice statement by the American Geriatrics Society.2

To that end, the researchers in the current study compared the outcomes of patients given dexmedetomidine (0.1 μg/kg per h) intravenously with those of patients given a placebo (intravenous saline). The 700 participants, adults aged 65 and older who were admitted to the intensive care unit after undergoing noncardiac surgery, were randomly assigned to either the treatment group or the control group. They received dexmedetomidine or placebo upon admission to the intensive care unit (ICU) until 0800 h on the day after surgery. Twice daily for 7 days post-surgery, delirium was assessed using the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU).

The study findings show the following significant associations:

  • A lower incidence of delirium in the dexmedetomidine group vs the placebo group (9% vs 23%; odds ratio [OR] 0.35, 95% CI, 0.22-0.54; P <0.0001)
  • A higher incidence of hypertension in the placebo group vs the dexmedetomidine group (18% vs 10%; OR 0.50, 95% CI, 0.32-0.78; P =0.002)
  • A higher incidence of tachycardia in the placebo group vs the dexmedetomidine group (14% vs 7%; OR 0.44, 95% CI, 0.26-0.75; P =0.02)
  • No between-groups difference in the incidence of hypotension and bradycardia

A study published last year in Anesthesiology similarly found that dexmedetomidine reduced postoperative delirium by 14% in elderly patients following cardiac surgery, and it also led to delayed onset and shorter duration of delirium compared to propofol.3

These findings suggest that the incidence of postoperative delirium in older adults may be reduced with a low-dose of dexmedetomidine, which appears to have an excellent safety profile.

References

  1. Su X, Meng ZT, Wu XH, et al. Dexmedetomidine for prevention of delirium in elderly patients after non-cardiac surgery: a randomised, double-blind, placebo-controlled trial. Lancet. 2016; 388(10054):1893-1902.
  2. American Geriatrics Society Expert Panel on Postoperative Delirium in Older Adults. Postoperative delirium in older adults: best practice statement from the American Geriatrics Society. J Am Coll Surg. 2015; 220(2):136-148.e1.
  3. Djaiani G, Silverton N, Fedorko L, et al. Dexmedetomidine versus propofol sedation reduces delirium after cardiac surgery: a randomized controlled trial. Anesthesiology. 2016; 124(2):362-368.

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