How Effective Are Dexmedetomidine Routes of Administration for Postoperative Delirium?

Intravenous or intratracheal administration of dexmedetomidine, compared with an intranasal route, reduces rates of postoperative delirium (POD) following spinal surgery among patients aged 60 years and older, according to study findings published in Anesthesia & Analgesia.

Absorption of dexmedetomidine differs across administration routes, and previous studies have reported variation in rates of adverse outcomes on the basis of delivery route.

Patients (N=150) aged 60 years and older scheduled to undergo spinal surgery with general anesthesia were enrolled for this study. Researchers randomly assigned patients 1:1:1 to receive 0.6 mg/kg intravenous dose of dexmedetomidine 10 minutes before anesthesia (n=49), 0.5 mL of 1 mg/kg intranasal dexmedetomidine in both nostrils 30 minutes before anesthesia (n=50), or 0.6 mg/kg dexmedetomidine with 0.8% ropivacaine administered intratracheally 3 minutes after assisted breathing (n=49). The outcome of interest was the incidence of POD during the first 3 days after surgery.

The 3 treatment arms were well-balanced at baseline and had a mean age of 70.1 to 70.8 years, 50.0% to 55.1% were women, they had a median Mini-Cog score of 4, and 39 to 43 in each group had American Society of Anesthesiologists (ASA) score of II.

The rates of POD during the first 3 days were 28.0% for the intranasal group, 10.2% for the intratracheal group, and 6.1% for the intravenous group. Risk for POD was decreased for the intravenous route (odds ratio [OR], 0.17; 95% CI, 0.05-0.63; P <.017) and intratracheal route (OR, 0.29; 95% CI, 0.10-0.89; P <.017) compared with intranasal route.

For secondary outcomes, the intratracheal route was associated with a lower rate of postoperative sore throat at 2 hours compared with intranasal (OR, 0.30; 95% CI, 0.11-0.80; P <.017) or intravenous (OR, 0.44; 95% CI, 0.14-0.94; P <.017) routes. Pittsburgh Sleep Quality Index (PSQI) scores were lower for the intravenous recipients compared with intranasal group (median difference [MD], -1; 95% CI, -2 to -1; P <.017) and higher for the intratracheal recipients compared with intravenous group (MD, 1; 95% CI, 1-2; P <.017) on the second morning after surgery.

The intravenous route was associated with a higher rate of bradycardia and lower rate of postoperative nausea and vomiting compared with the intranasal route (both P <.017). The intranasal route was associated with a higher rate of hypertension than the other groups (both P <.017).

These findings may not be generalizable for younger patients or for other types of surgery.

The study authors concluded, “[F]or patients aged ≥60 years undergoing spinal surgery, compared with intranasal dexmedetomidine (1 μg/kg), both intravenous dexmedetomidine (0.6 μg/kg) and intratracheal dexmedetomidine (0.6 μg/kg) resulted in a lower incidence of POD within 3 days. Meanwhile, intravenous dexmedetomidine improved sleep quality, and intratracheal dexmedetomidine reduced the incidence of [postoperative sore throat] 2 hours after surgery.”