The Relationship Between Postoperative Pain And Early Postoperative Cognitive Function After Surgery In The Elderly

Background : With the aging of the population and the improvement of the people's quality of life and with the progress of surgical technique and anesthesia level ,there are more elderly people to accept various kinds of operations.Changes of postoperative cognitive function in elderly patients ,especially postoperative cognitive dysfunction impact the postoperative quality of life. It is significant to reduce incidence of change postoperative cognitive dysfunction in elderly patients with early identification of this state,and thus intervention measures.Objective : The present study aims to evaluate the early cognitive function of the elderly patients'after operations by making use of three different kinds of neuropsychological scales, and to evaluate the postoperative pain through visual analogue scale by the method of neuropsychology. This study intends to tentatively discuss the influence of postoperative travenous analgesia on the early cognitive function of the elderly patients'after operations, as well as the relativity between the grade of postoperative pain and the change of the early cognitive function of the elderly patients. Thus a clue for explaining relation between the postoperative pain and cognitive function of the elderly patients'after operations can be obtained.Methods:1. All the elderly patients adopt target-conrtolled infusion .The depth of anesthesia is evaluated by bispectral index. Vasoactive agent can used to keep stable hemodynamic necessarily.2. Congnitive function is assessed preoperatively and 6hr,24hr,72hr,7days postoperatively using three neuropsychological scales .They are MMSE,CDT,AFT.3. Patients access to patient-controlled in travenous analagesia for 48hr. The degree of pain is evaluated 24hr,48hr postoperatively using visual analogue scale .Results:1. The cognitive function scores of the three scales during four time periods after surgery are not distinct different compared with the preoperative baseline (P>0.05).2. Cases whose postoperative cognitive function scores of the three scales have decreased≥20% by comparing with the preoperative ones are considered to be significant changes in cognitive function. Some cases whose scores of cognitive function decreased by 20% are found by means of analyzing preoperative and postoperative scores of three scale. But cases in PCIA group are less than in the control group .There are significant statistical differences in cognitive function scores between the two groups.3. It is found that the cases in PCIA group are better than in the control group in postoperative cognitive function recovery 24hr, 72hr and 7 days after surgery through analyzing scores of MMSE scale(P<0.05). But they are not distinct different through analyzing scores of CDT and AFT scale at the same time.4. It has non-statistical significance that the scores of MMSE scale 24hr and 48hr after surgery is related with the ones of VAS scale (P>0.05).And it has non-statistical significance that the scores of AFT scale 24hr and 48hr after surgery is related with the ones of VAS scale (P>0.05). But it has statistical significance that the scores of CDT scales 24hr and 48hr after surgery is related with the ones of VAS scale(P<0.05),and it can be considered that there is inverse relationship between scores of CDT scales and VAS scale 24hr and 48hr after surgery .Conclusion:1. The change of the cognitive function after operations is related to the postoperative pain. Relieving the postoperative pain may reduce the bad mood caused by pain, and improve the scope of behavior and cognitioin significantly.2. The way of putting the pain under the lasting and effective control by postoperative intravenous analgesia is obviously useful for decrease the occurrence of postoperative cognitive dysfunction.3. As for the cognitive function in general, the evaluation of the cognitive function have something to do with the pain grade, but there is no absolute relativity between them.