Consciousness, Level Altered

This research is studying changes in awareness and metabolism in the brain that may take place in various brain regions stimulated with ultrasound (low-intensity focused ultrasound pulsation or LIFUP) while undergoing magnetic resonance imaging (MRI)-based brain measurements.

This pilot study in healthy volunteers aims to determine if biological sex has an impact on recovery from dexmedetomidine-induced unconsciousness, and if transcranial magnetic stimulation combined with electroencephalography (TMS-EEG) can be used to measure brain complexity during dexmedetomidine sedation without arousing study participants.

In the field of general anesthesia research, the neural mechanism underlying the loss of consciousness has long been a highly core issue. It remains unclear what consciousness is and how it emerges from brain activity. By studying anesthesia and sleep, the investigators aim to reveal what happens in the brain when consciousness is lost and when it returns. Dexmedetomidine, a widely used drug in clinical anesthetic practice, plays an important role in the anesthetic process due to its unique pharmacological properties. It hardly causes respiratory depression during the sedative and hypnotic process, which makes it occupy an important position in clinical anesthetic regimens. The emergence of stereoelectroencephalography (SEEG) technology has brought new opportunities for research on anesthesia mechanisms. Compared with traditional electroencephalographic (EEG), SEEG can directly penetrate into deep brain structures to record electrical activities, enabling precise localization of brain regions closely related to consciousness regulation. At present, although there have been some studies on the effects of dexmedetomidine on EEG activities, there are still many deficiencies. Most studies have focused on simple spectral analysis of EEG signals or observations of limited brain regions, lacking comprehensive multi-dimensional research on functional connectivity between brain regions, microstates, and complexity. Through monitoring key brain regions, the SEEG technology can obtain more targeted and accurate information, thereby providing strong support for comprehensively revealing the neural mechanisms of dexmedetomidine-induced loss of consciousness.

Unexpected deaths and unplanned intensive care unit (ICU) admissions are common during hospital stay and are often preceded by warning abnormalities in patients' vital signs. These abnormalities trigger Medical Emergency Team (MET) activation and up to 15% of patients visited by the MET is admitted to the ICU with an overall hospital stay after the MET intervention of approximately 2 weeks. Phosphocreatine (PCr) is a natural energy-buffering molecule associated with signals of mortality reduction in patients with acute cardiac conditions (according to meta-analytic finding from our group) and with encouraging beneficial effects on other acute organ failures (e.g. brain). The investigators designed a multi-center, randomized, placebo-controlled trial to confirm the promising beneficial effects of PCr in hospitalized patients. The investigators expects a reduction in hospital stay (measured as an increase in days alive and out of hospital at 30 days) when PCr is added to standard treatment in patients requiring MET intervention.