The Effect of Different Anesthesia Depths on Postoperative Cognitive Function of Tumor Patients Monitored by...

Objectives  The study aimed to examine the influence of different anesthesia depths monitored by Narcotrend on postoperative cognitive dysfunction (POCD) in elderly patients undergoing radical resection of gastrointestinal malignancies. Methods  Individuals in the control group ( n  = 40) maintained the Narcotrend index (NTI) at 50 to 59 monitored by Narcotrend, whereas the experimental group at 30 to 39. The mini-mental state examination (MMSE) scale and serum S100β concentration were used to evaluate the cognitive function. Cerebral oxygen metabolism and inflammation were evaluated, presenting as regional oxygen saturations of brain (rSO ₂ ) and cerebral oxygen uptake rate (CERO2), serum tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6). Results  Experimental group presented prominently high levels of rSO2 and low levels of CERO2 relative to controls, meanwhile with reduced serum TNF-α and IL-6. Individuals receiving deep anesthesia owned low levels of S100β and enhanced MMSE score, which showed negative correlation. Low incidence rate of POCD was detected in the experimental group. Both age (hazard ratio = 5.219, 95% confidence interval = 1.813-15.025) and NTI score (hazard ratio = 3.707, 95% confidence interval = 1.292-10.633) were independent influence factors for the onset of POCD. Conclusion  NTI maintained at 30 to 39 can reduce the incidence of POCD in the early postoperative period for elderly patients receiving gastrointestinal tumors surgery, the contribution might be attributed to the improvement of perioperative cerebral oxygen metabolism and inflammatory stress response.