Intrathecal Dexmedetomidine For Sedation And Anesthesia During Lower Limb Fracture Surgery

Objective: To explore the analgesic and sedative effects of intrathecal dexmedetomidine (DEX) during lower limb fracture surgery. Methods: We prospectively studied 88 patients undergoing elective lower limb fracture surgery and divided them into the DEX group (n=44) and midazolam (MID) group (n=44) by a random number table. Either dexmedetomidine infusion (DEX group) at a dose of 1 mu g/kg, or midazolam infusion (MID group) at a dose of 0.05 mg/kg was used for the patients who received successful intrathecal anesthesia to maintain the anesthetic effect. The levels of sedation and anesthesia and parameters of stress reactions, hemodynamic, respiratory and circulatory functions were compared perioperatively at different time points between the two groups, and the post-operative mental status, cognitive function and incidence of adverse reactions were compared between the two groups. Results: At T2 and T3, the mean arterial pressure, heart rate and arterial partial pressure of carbon dioxide showed significantly better results in the DEX group than in the MID group (all P<0.05). The pressure pain threshold was significantly higher (P<0.001), and the auditory evoked potential index, Ramsay Sedation Score (P<0.05 or P<0.001), and serum levels of norepinephrine, epinephrine and cortisol (P<0.001) were significantly lower in the DEX group than in the MID group. After the surgery, the Mini-Mental State Examination scores were significantly higher (P<0.01), and the total incidence of adverse reactions such as agitation and respiratory depression were significantly lower in the DEX group than in the MID group (P<0.05). Conclusion: Intrathecal DEX is ideal for procedural anesthesia and sedation during lower limb fracture surgery, which reduces intraoperative stress reactions significantly, maintains respiratory and circulatory stability, and exerts mild postoperative effects on mental and cognitive functions, with few adverse reactions such as respiratory depression.