The Influence of Propofol and Dexmedetomidine Sedation on Memory Consolidation

The study is a prospective, randomized, single blind design. Patients undergoing elective trauma surgery (arthroscopy, reconstructive foot surgery) under subarachnoidal anesthesia are enrolled in this study. All patients were randomly divided into three groups depending on the drug type: first - propofol, second - dexmedetomidine, third - control.

The Montreal cognitive assessment test (MoCA - test) is a high validity test. MoCA - test is used to determine cognitive impairments in patients in the pre-operative period. The MoCA test time is approximately 10 minutes. The maximum possible score is 30; 26 points and more are considered normal, 25 or less is evidence of cognitive impairment.

American Society of Anesthesiologists (ASA) physical status classification system is used to assess and communicate a patient's pre-anesthesia medical co-morbidities (ASA I - a normal healthy patient, ASA II - a patient with mild systemic disease, ASA III - a patient with severe systemic disease, ASA IV - a patient with severe systemic disease that is a constant threat to life, ASA V - a moribund patient who is not expected to survive without the operation, ASA VI - a declared brain-dead patient whose organs are being removed for donor purposes.

To determine the level of anxiety and depression in the preoperative period, patients are tested using the Hospital Anxiety and Depression Scale (HADS). Values on the HADS scale<7 points are interpreted as normal, with scores from 8 to 10 as subclinically expressed anxiety and/or depression, and above 10 points-clinically expressed anxiety and/or depression.

In the operating room intravenous (i.v.) peripheral canulla Vasofix Certo (B. Braun, Germany) with a diameter of 18 or 20 Gauge is inserted before the start of regional anesthesia for infusion therapy. Before spinal anesthesia an anesthesiologist inject 0.9% saline infusion (Grotex, Russia) of 6-8 ml/kg.