Postoperative cognitive dysfunction after inhalational anesthesia in elderly patients undergoing major surgery: the influence of anesthetic technique, cerebral injury and systemic inflammation.
BACKGROUND
Elderly patients are reportedly at higher risk of postoperative cognitive dysfunction (POCD) after inhalational anesthesia with sevoflurane. We hypothesized that the incidence of POCD would be higher in elderly patients undergoing major surgery under inhalational rather than intravenous anesthesia. We also measured plasma S-100β protein concentration as a biomarker of central nervous system injury, and plasma interleukin (IL)-6 and tumor necrosis factor (TNF)-α concentrations to judge the contribution of systemic inflammation to POCD.


METHODS
Ninety patients aged 65-75 years scheduled for resection of an esophageal carcinoma were randomly assigned to one of three groups (n = 30) as follows: a group receiving sevoflurane anesthesia (Group S); a group receiving preoperative methylprednisolone before sevoflurane anesthesia (Group S + MP); and a control group maintained with intravenous propofol (Group C). The mini-mental state examination (MMSE) and Montreal cognitive assessment (MoCA) were used to measure patients' cognitive function the day before surgery, and on the first, third and seventh postoperative days. The plasma concentrations of TNF-α, IL-6 and S-100β protein were measured 10 min before anesthesia, and on the first, third and seventh postoperative days.


RESULTS
There were no significant differences in the demographic or clinical characteristics, or perioperative hemodynamic status, of the three groups. The MMSE and MoCA scores were significantly lower in Group S than in the propofol control (Group C) and Group S + MP on the first, third and seventh postoperative days (P <0.05). Throughout the first postoperative week the plasma concentrations of TNF-α, IL-6, and S-100β protein were significantly elevated in Group S compared with Group C (P <0.05), but were significantly lower in Group S + MP than Group S (P <0.05).


CONCLUSIONS
The incidence of POCD was higher in elderly patients undergoing major surgery under inhalational anesthesia with sevoflurane than those maintained on intravenous propofol, and lower in elderly patients pro-treating with methylprednisolone. Furthermore, we found elevated plasma concentrations of S-100β protein, TNF-α and IL-6 in those receiving sevoflurane anesthesia.


BACKGROUND
ChiCTR-IOR-15007007 (02-09-2015).
Department of Anesthesiology, the Second Affiliated Hospital of Shandong University, Ji'nan, Shandong, 250033, China. qiaoyong.75@163.com.
Yong
Y
Qiao
Department of Anesthesiology, the Second Affiliated Hospital of Shandong University, Ji'nan, Shandong, 250033, China. fengh112002@163.com.
Hao
H
Feng
Department of Anesthesiology, Rizhao People's Hospital, Ri'zhao, 276000, Shandong, China. feishi_xin@126.com.
Tao
T
Zhao
Department of Anesthesiology, the Second Affiliated Hospital of Shandong University, Ji'nan, Shandong, 250033, China. yh75952@163.com.
Heng
H
Yan
Department of Anesthesiology, the Second Affiliated Hospital of Shandong University, Ji'nan, Shandong, 250033, China. 411296366@qq.com.
He
H
Zhang
Department of Anesthesiology, the Second Affiliated Hospital of Shandong University, Ji'nan, Shandong, 250033, China. lujnzx@sohu.com.
Xin
X
Zhao
D000368:Aged; D018685:Anesthetics, Inhalation / Q000008:administration & dosage* / Q000009:adverse effects; D018686:Anesthetics, Intravenous / Q000008:administration & dosage / Q000009:adverse effects; D003072:Cognition Disorders / Q000453:epidemiology* / Q000209:etiology; D004311:Double-Blind Method; D004938:Esophageal Neoplasms / Q000601:surgery; D005260:Female; D006801:Humans; D007249:Inflammation / Q000453:epidemiology*; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D008738:Methyl Ethers / Q000008:administration & dosage / Q000009:adverse effects; D008775:Methylprednisolone / Q000008:administration & dosage; D009483:Neuropsychological Tests; D011183:Postoperative Complications / Q000453:epidemiology* / Q000209:etiology; D015742:Propofol / Q000008:administration & dosage / Q000009:adverse effects; D011446:Prospective Studies; D064568:S100 Calcium Binding Protein beta Subunit / Q000097:blood; D000077149:Sevoflurane; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; C508600:IL6 protein, human; D015850:Interleukin-6; D008738:Methyl Ethers; D064568:S100 Calcium Binding Protein beta Subunit; D014409:Tumor Necrosis Factor-alpha; D000077149:Sevoflurane; D008775:Methylprednisolone; D015742:Propofol