Application Of Subanesthetic Dose Of Esketamine Combined With Dexmedetomidine In Elderly Patients Undergoing Hip Fracture Surgery

Objective To investigate whether subanesthetic dose of esketamine combined with dexmedetomidine has more advantages in sedative effect,hemodynamics and perioperative analgesia than traditional dexmedetomidine in elderly patients with hip fracture undergoing lumbosacral plexus block guided by ultrasound and nerve stimulator.Methods A total of 80 elderly patients undergoing unilateral hip fracture surgery from June 2021 to June 2022 were selected and divided into two groups according to the random number method(40 cases in each group): Group DK(sub-anesthetic dose of esketamine combined with dexmedetomidine)and group D(dexmedetomidine).Lumbosacral plexus block was used under the guidance of ultrasound and nerve stimulator in both groups.In group D,a loading dose of dexmedetomidine 1μg/kg was infused intravenously over 10 min before nerve block,followed by a continuous infusion of 0.5μg/kg/h until 20 min before the end of surgery.In group DK,on the basis of group D,esketamine 0.2mg/kg was injected intravenously before the nerve block operation,and then 0.2mg/kg/h was maintained until 20 min before the end of the operation.During the operation,the nasopharyngeal airway was connected to the anesthesia machine,and the patients in both groups retained spontaneous breathing.The sedation(Ramsay sedation score),MAP,HR and Sp O2 were recorded at five different time points: the time of entering the operating room(T0),the time of skin incision(T1),the time of intramedullary nail implantation(T2),the end of operation(T3),and 30 min after operation(T4).The onset time of sedation,VAS score when changing position,and adverse cardiovascular events were recorded in the two groups.VAS scores were recorded at 4h,8h,12 h,24h and 48 h after operation.The occurrence of perioperative adverse reactions(intraoperative respiratory depression,excessive salivation,postoperative nausea and vomiting,dizziness,and hallucinations)was recorded.Results There were no significant differences in gender,age,BMI,ASA classification,operation time and blood loss between the two groups(P > 0.05).Compared with T0,MAP was significantly decreased at T1 and T2,and HR was decreased at T1-T4 in group D(P < 0.05).In group DK,MAP at T2 was significantly lower than that at T0(P< 0.05),and HR at T1-T4 was not significantly different from that at T0(P > 0.05).There was a significant difference in MAP at T2 between the two groups(P < 0.05).There was a significant difference in HR at T1 and T2 between the two groups(P <0.05).Compared with group D,the onset time of sedation was significantly shortened(P< 0.05),and the Ramsay scores at T1,T2 and T3 were significantly increased in group DK(P < 0.05).The VAS score and the incidence of bradycardia during postural change were significantly decreased in group DK(P < 0.05).The VAS scores at 4h,8h and 12 h after operation and the number of presses at 48 h after operation in group DK were significantly lower than those in group D(P < 0.05).There was no statistical difference in the incidence of perioperative adverse reactions between the two groups(P < 0.05).Conclusions On the basis of lumbosacral plexus block guided by ultrasound and nerve stimulator,compared with dexmedetomidine alone,subanesthetic dose of esketamine combined with lumbosacral plexus block can shorten the onset time of sedation,improve the sedation effect,maintain more stable hemodynamics,and provide more perfect perioperative analgesia without obvious adverse reactions in elderly patients undergoing hip fracture surgery.