Delayed Neurocognitive Recovery

With aging population, more older patients will receive major surgery for cancer. Older patients are at increased risk of postoperative neurocognitive complications including delayed neurocognitive recovery (dNCR), which is associated with prolonged hospital stay, raised complications, and impaired quality of life. Intraoperative hypothermia occurs in 57.1%-78.6% of patients undergoing major cancer surgery, especially in the elderly. Studies show that intraoperative hypothermia suppresses immune function, interferes with anesthetic metabolism, and delays anesthesia emergence. All these may be correlated with the occurrence of early postoperative dNCR. This study aims to verify whether intraoperative targeted temperature management (target core temperature: 36.8°C) compared with conventional temperature management (core temperature: 35.5°C) can reduce the incidence of dNCR in older patients undergoing major cancer surgery.

In this study, the investigators want to examine the effects of intravenous anesthetic drugs and gases on cognitive functions in the postoperative period in individuals who will undergo surgery for obesity. The investigators believe that the anesthesia method we apply with inhalation gases is also as reliable method as total intravenous anesthesia for postoperative cognitive functions in these patients who undergoe sleeve gastrectomy. The anesthesia method applied intravenously and with inahalational gases have been applied safely for many years. Comparisons between these two anesthesia technics in obese individuals and for postoperative cognitive dysfunctions are limited. Studies on the examination of cognitive functions in postoperative patients have gained momentum with the use of neuropsychiatric tests performed on patients who have undergone cardiac surgery and these tests have also been performed on individuals who have undergone non-cardiac surgery. And yet, similar declines in cognitive functions have been observed. For these reasons, the effects of surgery itself and anesthesia methods on cognitive functions have been studied up to date. In this study, the investigators plan to evaluate patients who will undergo obesity surgery in both anesthesia methods by the recovery times from anesthesia and the residual effects of anesthesia, and after awakening they plan to evaluate their cognitive functions with neuropsychiatric tests that will be performed at certain intervals.

The Sleep Optimization for Brain Health Outcomes in Older Surgical Patients (SLEEP-BOOST) is a pilot randomized, controlled, singled-blinded (participant) trial in major orthopedic joint surgery patients that will build on a previously clinically tested cognitive behavioral therapy for insomnia (CBT-I) mobile application paired with a wearable device (wrist actigraphy).

Esketamine is frequently used during the perioperative period for supplemental analgesia. Small sample size trials showed that subanesthetic dose esketamine may decrease postoperative neurocognitive complications. However, conflicting results exist and optimal dose of esketamine remains to be determined. This dose-exploring pilot trial is designed to evaluate the safety and efficacy of three different perioperative esketamine dosing regimens in older patients undergoing major non-cardiac surgery. The primary purpose is to explore the optimal dosing strategy that produce maximal neurocognitive benefits with minimal adverse neuropsychiatric symptoms.

The impact of anesthesia depths on early postoperative neurocognitive complications after total intravenous anesthesia (TIVA) remains controversial. In some studies investigating TIVA, anesthesiologists mainly achieve the target depth of anesthesia by adjusting the dose of propofol, whereas the doses of opioids remains comparable between different anesthetic depth groups, possibly resulting inadequate analgesia. This study is aimed to investigate the impact of different anesthesia depths maintained by target-controlled infusion of propofol and remifentanil at a fixed ratio on the incidence of early postoperative neurocognitive complications in older patients undergoing noncardiac surgery.

Patients with preoperative cognitive impairment are at increased risks of delayed neurocognitive recovery (DNR) and postoperative neurocognitive disorder (POCD). Repetitive transcranial magnetic stimulation (rTMS) has been used to improve cognitive function in patients with cognitive impairement. This trial is designed to compare the effects of rTMS versus sham intervention on postoperative neurocognitive function in patients with preoperative cognitive impairment.