Effect Of Different Administration Routes Of Dexmedetomidine On Postoperative Delirium In Elderly Patients Undergoing Spinal Surgery

Objective To compare the effect of different administration routes of dexmedetomidine on postoperative delirium in elderly patients undergoing spinal surgery.Methods A total of 150 patients(ASA class I-III,age ≥ 60 years)who were scheduled to undergo spinal surgery in the Third Affiliated Hospital of Anhui Medical University(The First People’s Hospital of Hefei)from June 2021 to March 2022 were selected.They were randomly divided into an IV group,an IN group and an IE group,with 50 people in each group.The three groups respectively received intravenous dexmedetomidine(0.6μg/kg),intranasal dexmedetomidine(1 μg/kg)before anesthesia induction,or intratracheal dexmedetomidine(0.6μg/kg)after anesthesia induction.Normal saline in the same volume was administered in the same way for patients in each group as the other two administration routes.The preoperative cognitive function of patients was assessed by Mini-Cog.The 3-Minute Diagnostic Interview for CAM-defined Delirium Chinese version(3D-CAM-CN)was used to evaluate the incidence of delirium during the first 3 postoperative days.The quality of sleep were assessed before the operation and on the first,second and third mornings after surgery by the Pittsburgh Sleep Quality Index(PSQI).Record the intraoperative hemodynamic changes,the incidence rates of postoperative sore throat(POST)at 2 h and 24 h after surgery,adverse events from the start of study drug administration until 2 h after surgery.Results Within 3 days after surgery,the incidence of POD was significantly lower in the IV group than that in the IN group(OR=0.17,95% CI 0.05-0.63;P < 0.017),and the incidence of delirium was lower in the IE group than that in the IN group(OR =0.29,95% CI 0.10-0.89;P < 0.017).Whereas,there was no difference between the intratracheal and intravenous groups(OR = 1.74,95% CI 0.40-7.73;P > 0.017).The rate of POST was lower in the intratracheal group than that in the other two groups at 2h after surgery(7 of 49 [14.3%] vs 12 of 49 [24.5%] vs 18 of 50 [36.0%],P < 0.017,respectively).Intravenous dexmedetomidine had the lowest Pittsburgh Sleep Quality Index score on the second morning after surgery(median [IQR]: 4 [3-5] vs 6 [4-7] vs 6[4-7],P < 0.017,respectively).Compared with the intranasal group,the intravenous group had a higher rate of bradycardia(OR=5.40,95% CI 1.10-26.44;P < 0.017)and a lower incidence of postoperative nausea and vomiting(OR=0.11,95% CI 0.01-0.91;P < 0.017).The intranasal group was associated with the highest incidence of hypertension(P < 0.017).The IV group and the IE group exhibited more stable hemodynamics during intubation and surgery.Conclusion For patients aged ≥ 60 years undergoing spinal surgery,compared with the intranasal route of dexmedetomidine,intravenous and intratracheal dexmedetomidine reduced the incidence of early POD.Meanwhile,intravenous dexmedetomidine was associated with better sleep quality after surgery,and intratracheal dexmedetomidine resulted in a lower incidence of POST.