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Related Concept Videos

General Anesthesia: Overview01:24

General Anesthesia: Overview

Anesthesia is a medical procedure that uses drugs for CNS suppression to enable painless surgeries and procedures. The selection of anesthetics is influenced by their pharmacokinetic properties, side effects, and patient characteristics. Various types of anesthesia include general, local, regional, spinal, and inhalational.
General anesthesia induces unconsciousness in the whole body, while the others target specific areas or sensations. It is administered to minimize adverse effects, maintain...
Stages of General Anesthesia01:22

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Various sedation levels offer significant advantages in facilitating procedural interventions for patients undergoing medical or invasive surgical procedures. These levels span from anxiolysis to general anesthesia, providing a spectrum of sedative effects to cater to specific patient needs. Anxiolysis reduces anxiety and is achieved through minimal sedation, enabling patients to remain awake and responsive while feeling more at ease during the procedure. This level can benefit minor...
Subconsciousness and No Awareness01:15

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Parenteral Anesthetics: Overview01:24

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Intravenous anesthetics are drugs administered parenterally to induce anesthesia or sedation. Propofol is a widely used agent formulated as a 1% emulsion in soybean oil, glycerol, and egg phosphatide. It induces rapid anesthesia primarily due to its rapid distribution from the bloodstream to target tissues and is metabolized in the liver. However, it can cause significant pain on injection and hypertriglyceridemia. Fospropofol, a water-based prodrug of propofol, lacks these adverse effects.
Inhalational Anesthetics: Overview01:20

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Local Anesthetics: Clinical Application as Spinal Anesthesia01:11

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Related Experiment Video

Updated: Jun 4, 2026

Recording Brain Electromagnetic Activity During the Administration of the Gaseous Anesthetic Agents Xenon and Nitrous Oxide in Healthy Volunteers
14:52

Recording Brain Electromagnetic Activity During the Administration of the Gaseous Anesthetic Agents Xenon and Nitrous Oxide in Healthy Volunteers

Published on: January 13, 2018

Awareness under general anesthesia.

Petra Bischoff1, Ingrid Rundshagen

  • 1Klinik für Anästhesiologie, Intensivmedizin und Schmerztherapie, Knappschaftskrankenhaus Bochum-Langendreer, Klinikum der Ruhr Universität Bochum, In der Schornau 23–25, 44892 Bochum, Germany.

Deutsches Arzteblatt International
|February 3, 2011
PubMed
Summary
This summary is machine-generated.

This review examines the rare but distressing phenomenon of patients remaining conscious during surgery. It highlights risk factors, potential long-term mental health impacts, and strategies for prevention and post-event care.

Keywords:
perioperative medicinepatient safetypsychological traumasedation protocols

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Published on: July 23, 2020

Area of Science:

  • Clinical outcomes research within anesthesia awareness medicine
  • Psychological trauma studies in perioperative care

Background:

No prior work had fully synthesized the complex psychological aftermath of surgical consciousness. It was already known that patients sometimes retain sensory perceptions during medical procedures. This gap motivated a comprehensive look at how such events manifest. Prior research has shown that these experiences often trigger severe emotional distress. That uncertainty drove the need to clarify the link between surgical awareness and psychiatric disorders. Researchers have long recognized that certain patient groups face heightened vulnerability. This review addresses the clinical reality of these rare occurrences. Understanding these outcomes remains a priority for improving patient safety and mental health support.

Purpose Of The Study:

The aim of this review is to synthesize current knowledge regarding the phenomenon of awareness during general anesthesia. Researchers sought to clarify why some patients retain consciousness while others do not. The study addresses the psychological impact of these events, which can range from mild distress to severe trauma. By examining existing literature, the authors intended to identify the primary risk factors associated with surgical consciousness. This work also explores the effectiveness of various preventative measures currently employed in clinical practice. The motivation stems from the need to reduce the incidence of these horrific events for surgical patients. Furthermore, the authors aimed to provide guidance on managing patients who experience such consciousness during their procedures. This synthesis serves to inform medical staff about the importance of depth-of-anesthesia management.

Main Methods:

The review approach involved a selective examination of existing clinical literature regarding surgical consciousness. Investigators synthesized data from various studies to identify common risk factors and patient outcomes. The team evaluated both patient-related and surgery-related variables to categorize potential triggers. Researchers assessed the effectiveness of current preventative strategies, including pharmacological interventions and monitoring tools. This methodology focused on gathering evidence from diverse medical settings to provide a broad overview. The authors systematically compared different anesthesia protocols to determine their impact on patient safety. They analyzed reported incidence rates across different age groups to highlight specific vulnerabilities. This synthesis provides a structured look at how clinical practices influence the occurrence of these rare events.

Main Results:

Key findings from the literature indicate that awareness occurs in approximately 0.1% to 0.2% of operations. This equates to one or two instances for every 1000 procedures performed under general anesthesia. The data show that children are 8 to 10 times more likely to experience these events than adults. Researchers identified that patient-related factors include high ASA physical status and history of medication abuse. Surgery-related risks encompass emergency procedures, night-time operations, and specific interventions like Caesarean sections. The evidence confirms that anesthesia-related factors involve the omission of benzodiazepines or the administration of muscle relaxants. While monitoring tools like electroencephalography provide some utility, the findings confirm they do not eliminate all risks. The literature highlights that these events can lead to severe psychiatric conditions, including post-traumatic stress disorder and depression.

Conclusions:

The authors propose that awareness during surgery represents a significant clinical challenge requiring proactive management. Synthesis and implications suggest that training staff on these risks helps reduce occurrence rates. Experts emphasize that benzodiazepines serve as a protective measure against incomplete unconsciousness. The literature indicates that avoiding muscle relaxants when possible lowers the likelihood of these events. Researchers note that electroencephalography monitoring provides utility but cannot fully prevent every instance of consciousness. If these events occur, the team must provide rapid, interdisciplinary support to mitigate long-term psychiatric damage. The review highlights that children face substantially higher risks compared to adult populations. Clinicians should prioritize early intervention to prevent the development of chronic post-traumatic stress symptoms.

The researchers propose that awareness arises from insufficient anesthetic depth, leading to incomplete unconsciousness. This state allows patients to experience auditory or tactile sensations, which contrasts with the intended total loss of awareness during surgical procedures.

The authors identify benzodiazepines as a protective pharmacological agent. In contrast, the use of muscle relaxants is cited as a potential risk factor that may mask the signs of inadequate anesthesia depth.

The review suggests that emergency procedures, night surgeries, and Caesarean sections are surgery-related conditions that increase risk. These situations differ from elective, daytime operations where anesthesia management is typically more controlled and predictable.

The authors note that electroencephalography monitoring is an effective tool for tracking brain activity. However, they clarify that this technology offers no absolute guarantee against awareness, unlike the more reliable use of specific sedative protocols.

The researchers report that children experience these events at a rate 8 to 10 times higher than adults. This demographic disparity highlights a significant difference in vulnerability compared to the general surgical population.

The authors state that rapid, interdisciplinary treatment is necessary to minimize long-term sequelae. This approach is preferred over delayed care, which may allow psychopathological phenomena like depression or suicidality to become more entrenched.