The influence of dexamethasone administration in spinal anesthesia for femur fracture on postoperative cognitive dysfunction

Background and purpose: Cognitive side-effects often complicate postoperative care especially in elderly and fragile patients.The aim of this research is to establish the influence of intrathecal dexamethasone administration in spinal anesthesia with levobupivacaine on postoperative pain, consciousness and values of cortisol levels for patients with femur fracture. Methods: The study is planned as a prospective, interventional, randomized clinical trial. A total of 60 patients ASA2 and ASA3 status, scheduled for surgical procedures will be sorted into two groups and undergo surgery. One group will have spinal anesthesia with levobupivacaine, SA group, and the other study group will have spinal anesthesia with addition of dexamethasone, DSA group. The primary outcome measure is the occurrence of postoperative disturbance of consciousness and plasma cortisol levels. As a secondary outcome measure, we are following pain intensity, blood glucose levels and recovery. Cortisol and glucose are analysed in five measurements. Peripheral venous blood samples are collected before anesthesia, one hour after surgery, third, fifth and on the tenth day after surgery. Postoperative cognitive dysfunction is defined by using Confusion Assessment Method (CAM) criteria. Visual analog scale (VAS) is used to record pain severity among patients. Results: We collected data for 28 patients so far. Preoperative cortisol levels were 713,25nmol/L,pain intensity(VASscore) 8,3. Postoperative cortisol plasma levels in 17 patients in DSA group were significantly lower 384(184-511) nmol/L in comparison to 11 patients in SA group with postoperative cotisol plasma levels 551(397-753) nmol/L. The duration of analgesia in DSA group was 428(350-510) minutes and in SA group 212(183- 254) minutes. According to CAM criteria, postoperative cognitive disturbances were seen in 8 (72%) patients in SA group, and 3 (17%) patients in DSA group. Conclusion: The addition of dexamethasone to the local anesthetic has proven so far that it significantly prolongs the duration of sensory block and, thus, decreases opioid requirements and postoperative cognitive disturbances