Effect Of Controlled Hypotension On Early Cognitive Function In Elderly Patients After Transsphenoidal Pituitary Tumor Resection

BACKGROUND:Recently studies and clinical applications showed that hypotensive anaesthesia could reduce blood loss, which decreased the rate of blood transfusion during operation. At the same time, the reduce of blood loss can also improve surgical field, which provide convenient to operators and reduce operative time. Hypotension may cause hypoperfusion of vital organs. Brain is the most sensitive organ to ischemia and hypoxia. But, brain has a good ability of self-regulation in blood perfusion. So, it is unknown whether controlled hypotension could cause cerebral damage. We also don’t understand the effect of controlled hypotension on post-operative cognitive function(POCD).OBJECTIVE:To observe the effect of controlled hypotension on early cognitive function in elderly patients after transsphenoidal pituitary tumor resection.METHODS:50patients undergoing transsphenoidal pituitary tumor resection, including33male cases,17female cases, from October2012to March2013, in the operative room of Shandong Provincial Hospital. All patients meet the following requirements:ASA Ⅰ-Ⅱ,junior high school and above degree, normal blood coagulation function, no obvious heart, lung, liver or kidney function damage, no definite neurological or psychiatric history before operation, no alcohol or drug dependence history, no serious vision or hearing barrier or unable to communicate with visitors for other reasons.50patients were randomly divided into group C and group CP. The2groups received the same induction of general anaesthesia, group CP started controlled hypotension by infusion of sodium nitroprusside at the beginning of the operation, the mean arterial pressure (MAP) was decreased about30%, and the MAP is not less than60mmHg,group C did not use controlled hypotension. Maintain the two groups of patients’end-tidal carbon dioxide partial pressure in the normal range during operation, maintain anaesthesia by infusion of propofol and cisatracurium. Continuous monitoring the heart rate(HR), MAP and pulse oxygen saturation (SPO2) in the operation. Assess the cognitive function of all the patients with MMSE, on the day before operation and4days after operation respectively. Extract peripheral venous blood3ml at these4time points:the beginning of anaesthesia (TO), the end of operation (T1),6hours after operation (T2),24hours after operation (T3) and then monitor the content of S-100(3protein and neuron specific enolase (NSE) respectively.RESULTS:There are total5cases of POCD occurred in the2groups of patients. Group C has2cases with the incidence of8%, and group CP has3cases with the incidence of12%, the incidence of POCD between the groups had no significant difference (P>0.05). There is no statistical significance of S-100β protein and NSE level between the2groups at each time point(P>0.05). The S-100β protein and NSE level of the2groups after operation are both higher than before, the difference is statistically significant (P<0.05). The S-100β protein and NSE level of patients with POCD are significantly higher than the normal(P<0.05).CONCLUSIONS:It doesn’t increase the incidence of POCD and aggravate brain damage, with controlled hypotension by using sodium nitroprusside, during transsphenoidal pituitary tumor resection. Aneasthesia and operation can raise the S-100(3protein and NSE level in patients after operation. The increasing of S-100β protein and NSE content in serum may reflect the occurrence of POCD.