Esketamine has promising anti-inflammatory effects in orthopedic surgery and plays a protective role in postoperative cognitive function and pain management.

objectiveTo investigate the effects of subanesthetic doses of esketamine on serum inflammatory cytokine levels and its impact on postoperative cognition and pain in patients undergoing elective orthopedic surgery.

methodsFrom November 2023 to March 2024, patients scheduled for elective orthopedic surgery were randomly divided into an observation group or a control group, with 100 patients in each group (ChiCTR2300079156). The observation group received an intravenous injection of 0.25 mg/kg esketamine before the induction of general anesthesia, while the control group was administered an equivalent volume of normal saline. Postoperative measurements included serum levels of interleukin-6 (IL-6), interleukin-1 (IL-1), and interleukin-10 (IL-10), as well as immunoglobulin levels (IgM and IgG), complete blood count (including white blood cell count, hemoglobin, and platelet count), intraoperative blood loss, cognitive function scores (assessed using the Mini-Mental State Examination [MMSE]), postoperative pain scores, and the incidence of adverse reactions (including nausea, vomiting, headache, dizziness, hallucinations, agitation, allergic reactions, and cardiovascular and respiratory responses).

resultsPostoperatively, serum levels of IL-6 and IL-1 in the observation group were significantly lower than those in the control group (P<0.05), while IL-10 levels were significantly higher (P<0.05). The control group showed a significant decrease in immunoglobulin levels (IgM and IgG) after surgery, whereas the observation group exhibited higher postoperative immunoglobulin levels compared to control group. In terms of complete blood count, the observation group had significantly better white blood cell and platelet counts compared to the control group (P<0.05), with no significant difference in hemoglobin levels. Intraoperative blood loss was significantly lower in the observation group (P<0.05). Cognitive function, as measured by the MMSE scores, was significantly better in the observation group compared to the control group at 6 and 24 hours postoperatively (P<0.05). Additionally, the observation group had significantly lower pain scores at 6 and 24 hours postoperatively and a lower incidence of adverse reactions.

conclusionSubanesthetic doses of esketamine in elective orthopedic surgery can effectively reduce postoperative inflammatory cytokine levels, improve immunoglobulin levels, reduce intraoperative blood loss, protect postoperative cognitive function, and significantly decrease the incidence of postoperative pain and adverse reactions. These findings suggest that subanesthetic dosing of esketamine has a high level of safety and efficacy in this clinical setting.