Effects Of Lower Level Controlled Hypotension On Postoperative Cognitive Dysfunction In Patients Affer Spinal Surgery

Objective To investigate the effect of lower level controlled hypotension(MAP 45-50mmhg) on postoperative cognitive dysfunction in patients affer spinal surgery and provide a reference for clinical applicationMethods Sixty ASAⅠ-Ⅱadult patients aged 18-59 yr weighing 45-85 kg undergoing lumbar decompression and bone graft fixation operation under general anesthesia were randomly divided into three groups (n=20 each):normal blood pressure group(C group),clinical level controlled hypotension group(D1 group:55-65mmhg) and lower level controlled hypotension group(D2 group:45-50mmhg).With no treatment given to C group,D1 and D2 groups were infused with sodium nitroprusside(SNP) continuously at 0.5-6μg/kg·min from the beginning of operation to reach mean arterial pressure (MAP) at target blood pressure (D1 group:55-65mmHg, D2 group:45-50mmHg) in 30min. The MAP was.maintained at this level Blood samples were taken for detecting SjvO2,NSE,S100βprotein at 10 min before depressurization, the time reaching target BP,60 min after reaching target BP, the time to recover BP, upon completion of surgery.The postoperative cognitive dysfunction was assessed 1 day before (base line) and at 1d,2d,3d,5d after surgery using Minimental State examination (MMSE) and scored.Results 1. Compared with group C, the changes of SjvO2,NSE,S100βprotein in groups D1 and D2 were not significant(P>0.05).2.The MMSE scores at 1d,2d,3d,5d after operation were not significantly different from the baseline values before anesthesia in three groups(P>0.05).There was no significant difference in MMSE scores after operation among three groups(P>0.05). The postoperative cognitive dysfunction was not observed after operation in three groups.Conclusion lower level controlled hypotension (MAP 45-50mmhg) induced by SNP has no significant influence on on postoperative cognitive dysfunction in patients affer spinal surgery...