Clinical Studies Of Elderly Non-cardiac Surgery In Patients With Postoperative Delirium

Part 1The epidemiological survey of postoperative delirium in elderly noncardiac surgical patientsObjective To observe the incidence rate of postoperative delirium in elderly noncardiac surgical patients in Peking Medical college Hospital (PUMCH) and analyze the perioperative risk factors. Methods A cluster sampling method was adopted in this cross-sectional study. 718 patients, aged 65 or older, undergoing elective noncardiac surgeries were recruited during the period of August to December, 2006. The enrolled patients were interviewed at the day before surgery and an informed consent was obtained. The same interviewer evaluated the patients prospectively for delirium with the Confusion Assessment Method (CAM)during the first three postoperative days. Other information including previous medical history, comorbidities, anesthetics, perioperative medications and so on, were also recorded.Results Delirium occurred in 80 patients at some time-points during the first three postoperative days. The Logistic stepwise regression analysis indicated that the perioperative risk factors of delirium included advanced age, cerebrovascular accident history, medications such as meperidine or scopolamine, hypotention during the operation, long duration operations(＞3h) and ICU admission after surgeries.Conclusion Advanced aged or previous history of cerebrovascular accident are risk factors to postoperative delirium. The incidence rate of postoperative delirium can be decreased by avoiding perioperative hypotension, mediacations of meperidine and scopolamine as well as by shortening of duration of operation. Part 2Perioperative melatonin and cortisol levels versus postoperative sleep disturbances in eldly patientsObjective To investigate the perioperative nocturnal melatonin and cortisol levels and the sleep disturbances in eldly patients. Methods Thirty two inpatients, ASAⅡ～Ⅲ, aged 65yr or older, undergoing lower extremity joint replacement or peripheral vascular surgeries were enrolled into general anesthesia group (group GA: n=16) and regional anesthesia group (group RA: n=16). Preoperative and postoperative day 1 to day 3 nocturnal (8pm～8am) urine samples were collected from all patients. Sixteen healthy volunteers with the same age as group GA from community inhabitants were recruited as a control group (group C: n=16). All subjects were asked to collect nocturnal urine samples for 4 consecutive days.. The melatonin sulfate and cortisol concentration of the urine samples were determined by ELISA and RIA respectively. A simple sleep disorder questionnaire were used to evaluate the sleep qualities every morning. Results Compared with group C, the perioperative nocturnal urine melatonin levels were decreased significantly in both group GA and group RA(P＜0.01). The preoperative nocturnal urine cortisol levels were not different among the three groups, but elevated significantly postoperatively in group GA and group RA(P＜0.01). Both the nocturnal urine melatonin and cortisol levels correlated well with sleep disorders(r=0.8574, P＜0.01 and r=0. 2667,p=0.0002, respectively). Conclusion In elderly surgical patients, the nocturnal urine melatonin levels are decreased perioperativly, while the cortisol levels are increased postoperativly. The decreased melatonin level may be one of the reasons of postoperative sleep disorders. Part 3Apolipoprotein E polymorphism vs postoperative deliriumObjective To investigate whether apolipoprotein E (APOE) genotypes associate with postoperative delirium in old noncardiac surgical patients. Methods Two hundred and twelve inpatients, aged 65yr or older, undergoing selective noncardiac surgeries were enrolled in this prospective observational cohort study. The patients were frequently interviewed and evaluated prospectively for delirium with the Confusion Assessment Method (CAM)during the first three postoperative days. DNA was extracted from whole blood samples obtained before surgery, and APOE genotype was determined using multiplex amplification refractory mutation system polymerase chain reaction(multi-ARMS PCR) technique. Results Delirium occurred in 45 patients during the first three postoperative days. Of the 212 patients, 18 (8.5%) possessed an APOEε4 allele (APOE4＋). There was no significant difference between delirious patients and non-delirious patients(6.7%: 9.0%, P=0.2622) in the presence of APOEε4 allele. Conclusion The presence ofAPOEε4 allele may not be associate with postoperative. APOE4＋might not be a predictator of postoperative delirium.