Intranasal dexmedetomidine in perioperative orthopedic anesthesia: Pharmacodynamic and harmacokinetic studies in adult patients

Abstract

Effective pain management is critical to ensure optimal recovery after orthopedic procedures, but postoperative pain remains an issue despite the use of multimodal analgesia. Alpha-2-agonist dexmedetomidine could be a valuable adjunct in orthopedic anesthesia due to its sedative, analgesic, anxiolytic, and antiemetic properties. Compared with other administration routes, intranasal administration of dexmedetomidine is advantageous due to favorable pharmacokinetics, noninvasiveness, and attenuated hemodynamic effects.

The present series examines intranasal dexmedetomidine as an adjunct in orthopedic anesthesia from different viewpoints. Specifically, we aim to characterize the effect of intranasally administered dexmedetomidine on postoperative pain and opioid consumption in patients undergoing total knee arthroplasty. We also aim to describe the population pharmacokinetics of intranasal dexmedetomidine on adult patients under general anesthesia for total joint arthroplasty and the effect of intranasal dexmedetomidine on perioperative hemodynamics, bleeding, and blood count; the feasibility of intranasal dexmedetomidine in treating postoperative restlessness, agitation, and pain in geriatric orthopedic patients are also evaluated.

Our results suggest that perioperative intranasal dexmedetomidine reduces postoperative pain and opioid consumption in patients undergoing total knee arthroplasty under general anesthesia, but the difference is not statistically significant in patients under spinal anesthesia. The bioavailability of intranasal dexmedetomidine was as good as observed in earlier studies, but the absorption half- time was longer than in prior pharmacokinetic investigations on adult subjects. The use of intranasal dexmedetomidine in geriatric orthopedic patients to treat postoperative restlessness, agitation, and pain seems feasible, but close observation of hemodynamic effects is warranted.

Our findings indicate that intranasal dexmedetomidine can be a safe and effective adjuvant in orthopedic surgery.