On no man's land: Subjective experiences during unresponsive and responsive sedative states induced by four different anesthetic agents.
Linda Radek, Lauri Koskinen, Nils Sandman, Lauri Laaksonen, Roosa E Kallionpää, Annalotta Scheinin, Ville Rajala, Anu Maksimow, Timo Laitio, Antti Revonsuo, Harry Scheinin, Katja Valli
Consciousness and Cognition November 1, 2021 DOI: 10.1016/j.concog.2021.103239 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Randomized controlled trial Peer reviewed |
|---|---|
| Sample size | 140 |
| Population | Healthy male participants |
| Interventions | Dexmedetomidine Propofol Sevoflurane S-ketamine |
| Duration | One-hour administration |
| Topics | Dreaming Ketamine |
| Keywords | Anesthesia Awareness Consciousness Dexmedetomidine Propofol Responsiveness Sevoflurane Subjective experiences |
| Key findings | Subjective experiences during sedation are common, with 46.9% of arousable participants reporting experiences, and the type of anesthetic may have minor effects on prevalence and complexity. |
Abstract
To understand how anesthetics with different molecular mechanisms affect consciousness, we explored subjective experiences recalled after responsive and unresponsive sedation induced with equisedative doses of dexmedetomidine, propofol, sevoflurane, and S-ketamine in healthy male participants (N = 140). The anesthetics were administered in experimental setting using target-controlled infusion or vapouriser for one hour. Interviews conducted after anesthetic administration revealed that 46.9% (n = 46) of arousable participants (n = 98) reported experiences, most frequently dreaming or memory incorporation of the setting. Participants receiving dexmedetomidine reported experiences most often while S-ketamine induced the most multimodal experiences. Responsiveness at the end of anesthetic administration did not affect the prevalence or content of reported experiences. These results demonstrate that subjective experiences during responsive and unresponsive sedation are common and anesthetic agents with different molecular mechanisms of action may have different effects on the prevalence and complexity of the experiences, albeit in the present sample the differences between drugs were minute.