Study of Depressive Symptoms Predicting Postoperative Cognitive Dysfunction

The aetiology of POCD is multifactorial. One described risk factor is preoperative existing depressive symptoms in patients undergoing cardiac surgery.

A total of 300 consecutive patients and 80 healthy controls will be enrolled in this study. Patients will be followed up at 7 days, 3 months and 1 year postoperatively. The co gnitive function will be tested and compared to tests done before surgery. Postoperatively - from the day of operation until the 7th day (except day 6) - grade of sedation, agitation, signs of delirium, pain, cardiac, respiratory, renal and infectious complications will be monitored.

Next to preoperative depressive symptoms we will also evaluate a diagnosed depression, anxiety, pain, health-related quality of life, physical comorbidities, adrenal cortical insufficiency, type of anaesthesia, intraoperative blood loss, organ complications, postoperative delirium, baseline cognitive functioning and the number of operations/anaesthetics in the study period after the initial operation as further potential predictors of POCD.

In addition, laboratory values and certain medications will be documented. These include: anaemia, hypercalcaemia, thyroidal gland hormones, electrolytes, creatinine, urea, glomerular filtration rate and cortisone therapy.

Inclusion criteria

for patients and healthy controls:

• Age > 60 years
• Written informed patient's consent

Additional Inclusion Criteria for patients:

• Elective non-cardiac surgery and non-neurosurgical procedures in general anaesthesia or combined general/regional anaesthesia
• Minimum of duration of operation 120 minutes
• Baseline testing 3-14 days preoperatively

Additional Inclusion Criteria for healthy controls:

• matched for age, gender and education
• no surgery over the study period

Exclusion criteria

for patients and healthy control:

• German not mother tongue
• Illiteracy
• Mental disability
• Vision impairment not correctable
• Hearing impairment not correctable
• Illegal substance abuse (current or past history)
• Alcohol abuse (current or past history)
• Chronic benzodiazepine use
• Psychosis (current or past history)
• Parkinson Disease
• Dementia
• Multiple sclerosis
• Epilepsy (current or past history)
• Cerebral tumor (current or past history)
• Apoplexy or intracranial bleeding (current or past history)
• Severe traumatic brain injury (current or past history)
• Severe liver disease (Child Pugh B, C, liver insufficiency)
• Severe kidney disease with dialysis
• Mini Mental Status Examination < 24 points