This study evaluates the influence of premedication on cognitive functions in patients undergoing transurethral resection of bladder tumor under spinal anesthesia. The aims of premedication are anxiolysis, analgesia and the reduction of perioperative risk among the patients with comorbidities. The patients will be randomly allocated to receive premedication either with opioid solely or with benzodiazepine combined with opioid. The anesthetic technique is standardized.

Trans-urethral resection of bladder tumor (TURBT) is the basic endoscopic procedure for management of bladder cancer and if there are no contraindications, it is performed under spinal anesthesia. The condition usually occurs among elderly patients, every 9 of 10 is older than 55 years. At this age the postoperative cognitive dysfunction (POCD) is a common complication as the risk increases with age. There are some studies indicating that using benzodiazepines during the perioperative period can also increase the number of registered POCD in patients undergoing anesthesia. Postoperative cognitive dysfunction (POCD) occurs after operations under regional and general anesthesia as well. The study was planed to evaluate the risk of POCD among urological patients and to asses whether combining benzodiazepines with opioids for premedication increases this risk.

The participants after giving the informed consent can participate in the study. The Beck Depression Inventory is performed to rule out the patients with depression. The cognitive functions are tested with Montreal Cognitive Assessment before the surgery and subsequently in the first 24 hours after surgery, three weeks later (while patients come back to receive histopathological examination), and finally six months after surgery (during control cystoscopy).

During anesthesia, the patients will be randomly allocated to receive premedication either with opioid solely or with benzodiazepine combined with opioid. The anesthetic technique is standardized. If the premedication is needed before the surgery the hydroxyzine will be administrated.

Inclusion Criteria:

• informed consent
• transurethral resection of the bladder tumor
• spinal anesthesia

Exclusion Criteria:

Exclusion Criteria:

• patients' refusal
• contraindications for spinal anesthesia
• skin lesions at injection site
• depression

the participant is not performed about the type of premedication performed