Comparison of the Effects of Dexmedetomidine and Lidocaine on Stress Response and Postoperative Delirium of Older Patients Undergoing Thoracoscopic Surgery: A Randomized Controlled Trial.

PURPOSE

We investigated the effects of intraoperative intravenous lidocaine or dexmedetomidine infusion on inflammatory factors and cognitive function in patients undergoing thoracoscopic surgery.

PATIENTS AND METHODS

Patients aged >65 years undergoing elective thoracoscopic lobectomy or segmentectomy were randomly grouped as dexmedetomidine group (group D), lidocaine group (group L), and control group (group C). The plasma cortisol, interleukin-6, and tumor necrosis factor-α concentrations were measured before anesthesia (T0) and immediately (T1), 24 h (T2), and 48 h postoperatively (T3). Postoperative delirium (POD) was assessed by 3D-CAM on days 2 and 7.

RESULTS

The cortisol concentrations decreased for all groups at T1 from T0 although they were significantly higher at T2. Group L had significantly lower interleukin-6 concentrations at T1 and T2 than the other groups (<0.05). The interleukin-6 concentrations were significantly higher at T1, T2, and T3 than at T0 for all the groups, significantly lower for groups D and L than for group C at T1 and T2 (<0.05), and significantly lower for group L than for group D at T2 (<0.05). The tumor necrosis factor-α concentrations were significantly higher at T1, T2, and T3 than at T0 for all the groups and significantly lower for groups D and L than for group C at T1 and T2 (<0.05), although they were not statistically significantly different for groups D and L. There were no statistically significant differences in the postoperative incidence of POD between the three groups on days 2 and day 7.

CONCLUSION

Intraoperative continuous intravenous lidocaine or dexmedetomidine infusion reduced surgical stress and inflammatory responses. The inhibitory effect of lidocaine on surgical stress remained significant for up to 24 h postoperatively without affecting patient awakening. However, the administration of either drug failed to prevent postoperative POD.