Anesthesia & AnalgesiaNovember 24, 2025Donggeon Lee, Hayoung Lee, Cheol-Hyeong Lee et al.
BACKGROUND: Drug-induced dreams during intravenous sedation vary by pharmacological agent and influence patient experiences, yet the role of preoperative positive suggestions in modulating these dreams is unclear. This study aimed to investigate the impact of preoperative positive suggestions on drug-induced dream recall (DIDR) frequency, dream content, and subjective perceptions during...
Low-dose ketamine may have an opioid-sparing effect in critically ill patients but may also predispose them to traumatic memories. We evaluated the effects of low-dose ketamine infusion in the intensive care unit (ICU) on fentanyl consumption and traumatic memories after hospital discharge. This randomized, double-blind, controlled trial was conducted at a university-based surgical ICU. 118...
The aim of this study was to investigate the effects of esketamine on the risk of postoperative delirium (POD) in adults undergoing on-pump cardiac valve surgery. In this randomized, triple-blind, controlled trial, 116 adult patients with an American Society of Anesthesiologists (ASA) grade Ⅱ or Ⅲ and a New York Heart Association (NYHA) grade Ⅱ or Ⅲ who underwent cardiac valve surgery with...
Concerns regarding the perioperative management of acute psychostimulant intoxication have been recognized for decades, but novel and diverse substances in this class continue to be developed. Despite the similarities in mechanisms of action among psychostimulants, each subclass within this broad category has unique receptor specificity and different mechanisms that play a role in patient...
Preoperative anxiety is widespread among patients scheduled for surgery, and pharmacologic anxiolysis has become a standard in the preoperative setting. The readily available drugs are effective and consistent with our tendency in modern medicine to treat problems pharmacologically. In addition, while hypnosis and contemplative techniques are emerging in some clinical settings,...
Ketamine anesthesia increased glucose metabolism in most brain regions compared to another intravenous anesthetic propofol. However, whether the changes in cerebral metabolic networks induced by ketamine share the same mechanism with propofol remains to be explored. The purpose of the present study was to identify specific features of metabolic network in rat brains during ketamine-induced...
Neurophysiologic complexity has been shown to decrease during states characterized by a depressed level of consciousness, such as sleep or anesthesia. Conversely, neurophysiologic complexity is increased during exposure to serotonergic psychedelics or subanesthetic doses of dissociative anesthetics. However, the neurochemical substrates underlying changes in neurophysiologic complexity are...
It is tough to write about psychedelics without a few gratuitous puns. Regardless, Michael Pollan’s “How to Change Your Mind” is definitely “mind expanding” and deserves my “highest” recommendation. Published in 2019, this book comprehensively and presciently covers a topic of increasing interest: whether psychedelic agents can revolutionize mental health. Pollan is not a Medical Doctor but is...
A quest for a systems-level neuroscientific basis of anesthetic-induced loss and return of consciousness has been in the forefront of research for the past 2 decades. Recent advances toward the discovery of underlying mechanisms have been achieved using experimental electrophysiology, multichannel electroencephalography, magnetoencephalography, and functional magnetic resonance imaging. By the...
BACKGROUND: In the immature brain, neuronal Ca2+ oscillations are present during a time period of high plasticity and regulate neuronal differentiation and synaptogenesis. In this study we examined the long-term blockade of hippocampal Ca2+ oscillations, the role of the N-methyl-D-aspartate (NMDA) receptors and the effects of S(+)-ketamine on neuronal synapsin expression. METHODS: Hippocampal...
From Joseph in the book of Genesis to the 2010 blockbuster Inception, dreams have been a source of fascination. The attraction seems to derive, in part, from their bizarreness. Indeed, it is rare to hear someone muse that “I had the craziest wakefulness last night.” But we are also compelled by the allure that dreams are imbued with meaning or that they reveal something about our psyche....
The use of ketamine may be associated with the recall of unpleasant dreams after sedation. We hypothesized that a positive suggestion before sedation could reduce the incidence of ketamine-induced unpleasant dreams. To test this hypothesis, we randomized 100 patients receiving sedation with ketamine for their procedure into 2 groups with 1 group having an anesthesiologist provide a...
The nature and mechanism of human consciousness is emerging as one of the most important scientific and philosophical questions of the 21st century. Disregarded as a subject of serious inquiry throughout most of the 20th century, it has now regained legitimacy as a scientific endeavor. The investigation of consciousness and the mechanisms of general anesthesia have begun to converge. In the...
UNLABELLED: We evaluated reports of randomized clinical trials in the perioperative and intensive care setting concerning ketamine's effects on the brain in patients with, or at risk for, neurological injury. We also reviewed other studies in humans on the drug's effects on the brain, and reports that examined ketamine in experimental brain injury. In the clinical setting, level II evidence...
Ketamine has a special position among anesthetic drugs. It was introduced into clinical practice >30 yr ago with the hope that it would function as a "monoanesthetic" drug: inducing analgesia, amnesia, loss of consciousness, and immobility. This dream was not fulfilled because significant side effects were soon reported. With the introduction of other IV anesthetic drugs, ketamine's role...
The neurophysiological effects of ketamine were studied at the single-neuron level in the somatosensory cortex of unanesthetized rats behaving in a treadmill movement paradigm. Chronically implanted 25-microns microwire electrodes were used to record spontaneous discharge, sensory responses, and sensorimotor-correlated activity of single neurons before and after ketamine administration....
*Associate Attending, Division of Anesthesiology, Cook County Hospital and Hektoen Institute for Medical Research; Assistant Professor of Medicine and Psychiatry, Chicago Medical School, Chicago, Illinois. †Chairman, Division of Anesthesiology, Cook County Hospital and Hektoen Institute for Medical Research; Associate Professor of Surgery (Anesthesiology), Northwestern University, School of...