Effect of lidocaine on prevention of postoperative delirium in elderly patients with intrathecal anesthesia:A randomized, controlled, double-blind prospective study

Abstract

Abstract Background Earlier findings have shown that elderly individuals are at high risk for postoperative delirium. Although the pathogenesis of this disease is still under study, it has been suggested that the release and inhibition of inflammatory factors contribute to its pathogenesis. Lidocaine is considered to have outstanding anti-inflammatory properties. The aim of this study was to observe changes in cognitive function after intraoperative lidocaine pump placement in elderly patients who underwent hip replacement surgery after intrathecal anesthesia. Methods Patients aged 60 to 80 years were selected as study subjects and randomly divided into a lidocaine group and a saline group. The Mini Mental State Examination(MMSE) score was assessed on the day before surgery (T1) and the third day after surgery (T2) for comparison. Venous blood samples were taken on T1, T2 and the fifth day after surgery (T3) for the detection of inflammatory factors. Results Statistical analysis of the data showed that, compared with those in the lidocaine group, the saline group had a lower MMSE score at T2 (26.6 ± 1.5 vs. 28.0 ± 0.9, P < 0.01) and a greater concentration of the proinflammatory factor interleukin-6 (172.4 ± 85 vs. 129.4 ± 46, P = 0.018). In addition, the concentration of the S100β protein in the lidocaine group decreased after reaching a peak at T2, which was not evident in the saline group. Conclusions These findings suggest that lidocaine may protect the nervous system by reducing the release of proinflammatory factors rather than increasing the release of anti-inflammatory factors. Trial registration This study was registered at ChineseClinicalTrials.gov ChiCTR2000039540 (30/10/2020).