The optimal dose of dexmedetomidine as a 0.59% ropivacaine adjuvant for epidural anesthesia in great saphenous varicose vein surgery, based on hemodynamics and anesthesia efficacy: a randomized, controlled, double-blind clinical trial.

OBJECTIVE

This study aimed to explore the optimal dose of dexmedetomidine as a 0.59% ropivacaine adjuvant for epidural anesthesia on perioperative hemodynamics and anesthesia efficacy in patients undergoing great saphenous varicose vein surgery.

METHODS

A total of 90 patients were randomly divided into three groups: 0.25 μg/kg dexmedetomidine combined with 0.59% ropivacaine epidural infusion group (ED group), 0.5 μg/kg dexmedetomidine combined with 0.59% ropivacaine epidural infusion group (ED group), and 0.75 μg/kg dexmedetomidine combined with 0.59% ropivacaine epidural infusion group (ED group). Hemodynamics, anesthesia efficiency, and adverse reactions were recorded.

MAIN RESULTS

Compared with the ED group, the ED group had lower systolic blood pressure at T (T, 95%CIs, 6.52-21.93,  < 0.001; T, 95%CIs, 2.88-18.21,  = 0.004; T, 95%CIs, 0.49-18.17,  = 0.035), and the diastolic blood pressure at T was decreased (T, 95%CIs, 4.55-14.36,  < 0.001; T, 95%CIs, 0.37-12.17,  = 0.033). Compared with the ED group, the ED group had higher systolic blood pressure at T (T, 95%CIs, 5.90-21.46,  < 0.001; T, 95%CIs, 2.07-17.55,  = 0.008) and higher diastolic blood pressure at T (T, 95%CIs, 2.91-12.81,  = 0.001; T, 95%CIs, 1.32-13.23,  = 0.011; T, 95%CIs, 0.14-11.52,  = 0.043). Compared with the ED group, the heart rate was significantly decreased at T in the ED group (T, 95%CIs, 2.25-15.72,  = 0.005; T, 95%CIs, 2.35-13.82,  = 0.003; T, 95%CIs, 0.50-9.79,  = 0.025; T, 95%CIs, 1.46-10.36,  = 0.005). The myocardial oxygen consumption in all three groups was significantly decreased at each time point compared to T ( < 0.05 or < 0.001), and no significant between-group differences were detected (>0.05). Compared with the ED group, the anesthesia efficiency of ED and ED groups was markedly enhanced, but the risk of bradycardia in ED and ED groups was dramatically increased (6 of 28 [21.4%] vs. 14 of 30 [46.7%] and 14 of 27 [51.9%],  = 0.023), one patient in the ED group experienced difficulty urinating, and remaining adverse reactions were mild in all three groups.

CONCLUSION

A measure of 0.5 μg/kg dexmedetomidine is the optimal dose as a 0.59% ropivacaine adjuvant for epidural anesthesia in patients undergoing great saphenous varicose vein surgery.

CLINICAL TRIAL REGISTRATION

http://www.chictr.org.cn/, registration number: ChiCTR2200060619.