Effect of Preoperative Oral Saline Administration on Postoperative Delirium in Older Persons: A Randomized Controlled Trial

OBJECTIVE: Postoperative delirium (POD) seriously affects recovery of older persons, increasing their mortality rate after surgery. We aimed to evaluate preoperative oral saline administration on postoperative delirium in older persons undergoing spinal decompression. DESIGN: A randomised controlled trial in a large tertiary hospital. SETTING AND PARTICIPANTS: A total of 76 older persons (≧65 years old) undergoing spinal surgery from May 2020 to January 2021. METHODS: Older persons (65–83 years old) who underwent elective spinal canal decompression were randomly grouped into either the control group (n = 38) or the intervention group (n = 38). The control group was forbidden from drinking 8 hours prior to the operation while the intervention group was administered 5 mL·kg(−1) of normal saline 2 hours before anesthesia. Hemodynamic indicators, diagnostic biomarkers, preoperative mini-mental status scores, and intraoperative fluid dynamics were recorded at baseline and at various postoperative timepoints. Subjects were then scored for POD and postoperative pain. RESULTS: S100β protein was lowered in S(1) (F(S1) = 12.289, P <0.001) and S(2) (F(S2) = 12.440, P <0.001) in the intervention group while mean arterial blood pressure (F(T1)= 42.997, P<0.001) and heart rate (F(T1)= 8.974, P=0.004) were increased. The Ln c-reactive protein of the intervention group was lowered 1 day postoperatively (F(S2) = 6.305, P = 0.014). The incidence of postoperative delirium in the control group was higher than in the intervention group (27.8% vs 8.3%, χ(2) = 4.547, P = 0.033). CONCLUSION: Preoperative oral saline can reduce the incidence of postoperative delirium in older persons by minimizing perioperative hemodynamic fluctuations and central nervous system damage.