Objective To investigate the effect of preoperative dexmedetomidine(DEX)combined with fascia iliac compartment block(FICB)analgesia on perioperative sleep quality and delirium in elderly patients with hip fracture.Methods A total of 90 elderly patients who received total hip replacement(THA)for hip fracture in our hospital from January 2021 to June 2023 were selectively included,and all patients were randomly divided into control group(n=30),FICB group(n=30)and combination group(n=30).Patients in control group were prepared according to routine surgical procedures before surgery.Patients in combination group and FICB group were given continuous ultrasus-guided iliofascial space block and analgesia two days before surgery after admission.Patients in combination group were given dexmedetomidine nose drops on the night before surgery,the day after surgery and the night after surgery.Visual analogue pain(VAS)scores were recorded at admission(Tl),30 minutes after nasal drops(T2),immediately after entry to the operating table(T3),and at the position of intraspinal anesthesia(T4).Hamilton Anxiety(HAM-A)score and Athens Insomnia Scale(AIS)score were recorded 1 day before surgery,1 day after surgery and 1 day after surgery.Adverse reactions and postoperative delirium(POD)were recorded one week after surgery.Results There were no significant differences in age,sex,body mass index(BMI),fracture type,anesthesia duration,operation time,blood loss and adverse reactions(except daytime sleepiness)among all groups(P＞0.05).The VAS scores of T2,T3 and T4 in the combination group were significantly lower than those in the other two groups.HAM-A and AIS scores were significantly lower than those of the other two groups(P＜0.05).The incidence and duration of postoperative delirium were significantly lower than those in the other two groups(P＜0.05).Conclusion Prospective randomized controlled trials show that FICB combined with DEX can relieve pain,improve perioperative sleep quality and relieve postoperative delirium in patients with THA.