Neurocognitive disorders after thyroid surgery: a randomized controlled trial

Objective. To improve the outcomes after thyroid surgery in female patients by identifying the optimal anesthetic options with minimal impact on cognitive potential. Material and methods. A single-center randomized longitudinal parallel-group controlled study included 120 female patients (aged 32—72 years, ASA II—III) who underwent thyroid surgery. Randomization was performed using the envelope method. In the SEVO group (n=40), anesthesia induction and maintenance were provided with sevoflurane; in the PROP group (n=40) — with propofol. In the COA group (n=40), induction was performed with propofol and anesthesia maintenance — with sevoflurane. The control group (for dichotomous Z-score of cognitive status) included 40 women (ASA I—II) without thyroid diseases. Monitoring: Harvard standard; anesthetic gas mixture analysis; consciousness depression degree (BIS); heart rate variability. We assessed cognitive status using the Montreal Cognitive Assessment Scale (MoCA test) before surgery, in 7 and 30 days after surgery. Results. In thyroid diseases, preoperative cognitive impairment was observed in 11.7% of patients. In patients with thyroid cancer, the risk of preoperative cognitive dysfunction was 11 times higher (p< 0.0001). The incidence of delayed neurocognitive recovery did not differ between groups (p=0.621). Delayed neurocognitive recovery increased the risk of prolonged hospital-stay by 3 times (OR 3.0248; 95% CI 1.3433—6.8114). The incidence of verified postoperative neurocognitive impairment was 50%, 45% and 15%, respectively (p=0.0002). COA reduced the risk of cognitive dysfunction by 5.1 times (OR 0.1950; 95% CI 0.0783—0.5158; p=0.001). Conclusion. In surgical treatment of thyroid diseases, the optimal option for anesthetic management regarding neuropsychological status is general anesthesia (induction with propofol, maintenance of anesthesia with sevoflurane).