Effect of Transcutaneous Electrical Acupoint Stimulation on Postoperative Delirium in Older Patients Undergoing...

Postoperative delirium (POD) is an acute and transient brain dysfunction in older patients, associated with multiple adverse outcomes and even increased mortality. This study aimed to evaluate the efficacy of transcutaneous electrical acupoint stimulation (TEAS) in preventing POD in older patients undergoing carotid endarterectomy (CEA) and to preliminarily explore the correlative factors associated with its clinical benefits.

Sixty-five geriatric patients undergoing CEA were enrolled and randomly assigned to a control group and a TEAS group. TEAS was applied to Baihui (GV20), Sanyinjiao (SP6), and Zusanli (ST36) acupoints from 30 minutes before anesthesia induction until the end of surgery. Patients in the control group were only connected to the electrodes at the same acupoints without electrical stimulation. The primary outcome was the incidence of POD during the first three postoperative days. The severity of POD and sleep quality were evaluated using Memorial Delirium Assessment Scale (MDAS) and Athens Insomnia Scale (AIS) scores, respectively. Perioperative optic nerve sheath diameter (ONSD) was measured via ultrasound at T0 (before anesthesia induction), T1 (two minutes after tracheal intubation), T2 (at the end of surgery), and T3 (24 hours after surgery). Meanwhile, perioperative plasma concentrations of tumor necrosis factor-alpha (TNF-α) and brain-derived neurotrophic factor (BDNF) were detected by enzyme-linked immunosorbent assay (ELISA).

Compared with the control group, TEAS significantly reduced the incidence and severity of POD within the first three postoperative days (all p < 0.05). Patients in the TEAS group had lower ONSD at T2 and T3 than those in the control group. Besides, TEAS decreased the AIS scores, the incidence of sleep disturbance, and TNF-α levels, while increasing the BDNF levels on the first day after surgery (all p < 0.05). Spearman correlation analyses revealed that MDAS scores were strongly positively correlated with ONSD (r = 0.631, p < 0.001), AIS scores (r = 0.522, p < 0.001), and TNF-α levels (r = 0.592, p < 0.001), as well as moderately negatively correlated with BDNF levels (r = -0.332, p = 0.007).

TEAS reduced the incidence and severity of POD in older patients undergoing CEA. Exploratory correlational analyses suggested potential links between this clinical benefit and relieved intracranial hypertension, improved early postoperative sleep quality, and suppressed inflammation; however, further large-cohort validation with rigorous mediation analyses is still warranted.

Chinese Clinical Trial Registry (ChiCTR2300076868, registration date: 23/10/2023).