To investigate the effect of subanesthetic dose esketamine hydrochloride injection combined with midazolam injection on hip replacement in elderly patients.

The elderly patients undergoing hip replacement were divided into control group and treatment group. The control group was given 0.02 mg·kg^-1 midazolam injection; the treatment group was given 0.02 mg·kg^-1 midazolam injection combined with 0.25 mg·kg^-1 esketamine hydrochloride injection. Anesthesia (sedation, analgesic effect), hemodynamic indexes, and safety evaluation.

There were 90 cases in the treatment group and 90 cases in the control group. The scores of sedation in the treatment group and the control group were (1.54±0.28) and (1.67±0.35) points, respectively; the scores of pain simulation at 2 h after operation were (3.16±0.47) and (3.38±0.59) points, respectively; at the end of the operation, the mean arterial pressure of the treatment group and the control group were (83.06±2.47) and (82.15±2.94) mmHg, respectively; the heart rate were (82.04±3.25) and (80.75±3.32) time·min^-1, respectively, and the difference was statistically significant (all P<0.05). The total incidence of adverse drug reactions in the treatment group and the control group was 8.89% (8 cases /90 cases) and 13.33% (12 cases /90 cases), respectively, with no statistical significance (P>0.05).

The subanesthetic dose of esketamine hydrochloride injection combined with midazolam hydrochloride injection can effectively stabilize the hemodynamic level of the body and reduce postoperative pain in elderly patients with hip replacement with good safety.