Dreaming during anesthesia and sedation

The relationship between different bispectral index and the occurrence of dreams in elective surgery under general anesthesia: protocol for a randomized controlled clinical trial

INTRODUCTION

Dreaming reported after anesthesia remains a poorly understood phenomenon. At present, there is a hypothesis that dreaming occurs intraoperatively and is related to light or inadequate anesthesia; thus, in order to further verify the hypothesis, we choose elective surgery under general anesthesia to observe whether the generation of dreams is related to the dose of general anesthetics maintenance.

METHODS AND ANALYSIS

This randomized, double-blind controlled trial to observe whether the generation of dreams is related to the dose of general anesthetics maintenance in the elective surgery under general anesthesia. A total of 124 participants will be randomly allocated to a low bispectral index or high bispectral index group at a ratio of 1:1. The Hospital Anxiety and Depression Scale (HADS) is used to assess the anxiety and depression status of participants during the perioperative period. Ramsay score is used to assess patients' sedation level after surgery in the PACU. Modified Brice questionnaire and awareness classification are used to assess whether patients experienced dreaming during the surgery.

ETHICS AND DISSEMINATION

This randomized, double-blind controlled trial received prospective ethics committee approval at the Human Research Ethical Committee of Shengjing Hospital, Shenyang, Liaoning Province, China (Institutional Review Board registration number 2021PS664K), and was compliant with the Declaration of Helsinki. Written informed consent was obtained from all subjects participating in the trial.

Complexities of human memory: relevance to anaesthetic practice

Mechanisms of anaesthetic actions on memory have largely focused on easily definable aspects of episodic memory, with emphasis on particular drug interactions on specific memory processes. However, the memory landscape of the perioperative experience includes many facets that lie outside these conceptualisations. These include patient recall of preoperative conversations, patient beliefs regarding allergies and unusual/uncommon anaesthetic events, memories of awareness, and particularly vivid dreams during anaesthesia. In no small part, memories are influenced by a patient's interpretations of events in light of their own belief systems. From the practitioner's point of view, relating fully to the patient's experience requires some framework of understanding. The purpose of this review is to highlight research over the previous decades on belief systems and their interactions with autobiographical memory, which organises episodic memories into a personally relevant narrative. As a result, memory is a set of continuously malleable processes, and is best described as a (re)constructive rather than photographic instantiation. Belief systems are separate but closely interacting processes with autobiographical memory. The interaction of a constantly evolving set of memories with belief systems can explain phenomena such as illusions, distortions, and (re)constructions of factitious events. How anaesthetics and our patient interactions influence these behaviours, and vice versa, will be important questions to explore and define with future research.

Intraoperative awareness and experience with a ketamine-based anaesthesia package to support emergency and essential surgery when no anaesthetist is available

INTRODUCTION

Five of the 7.2 billion people on earth have limited access to emergency and essential surgical procedures. The lack of safe, affordable and timely anaesthesia services are primary barriers to universal surgical coverage. The objective of this study was to assess intraoperative awareness when the 'Every Second Matters for Emergency and Essential Surgery - Ketamine' (ESM-Ketamine) package was used to support emergency and essential surgeries and painful procedures in rural Kenya when no anaesthetist was available.

METHODS

Forty-seven consecutive adult patients that underwent an operative procedure under ESM-Ketamine at Sagam Community Hospital in Luanda, Kenya were enrolled. Participants underwent two semi-structured interviews that explored the patient's experience with ESM-Ketamine both after the operative procedure and four to six weeks after surgery.

RESULTS

Forty-seven participants completed the first interview and 37 (78.7%) the second interview. Thirty-seven (78.7%) cases were procedural sedations and ten were (21.3%) emergency surgeries. Intraoperative awareness occurred in nine (24.3%) participants who underwent procedural sedation and two (20%) who underwent emergency surgery. Twenty-six (55.3%) participants reported dreams during the procedure. Thirty-two (86.5%) participants considered their experience positive, and 35 (95%) would recommend a procedure supported by ketamine to a friend.

DISCUSSION

Most patients whose painful procedures and emergency operations were supported by the ESM-Ketamine package when no anaesthetist was available reported favourable experiences.

Anesthetic dreaming, anesthesia awareness and patient satisfaction after deep sedation with propofol target controlled infusion: A prospective cohort study of patients undergoing day case breast surgery

Background

Anesthetic dreaming and anesthesia awareness are well distinct phenomena. Although the incidence of intraoperative awareness is more common among patients who reported a dream after surgery, the exact correlation between the two phenomena remains an unsolved rebus. The main purpose of this study was to investigate anesthetic dreaming, anesthesia awareness and psychological consequences eventually occurred under deep sedation. Intraoperative dreaming experiences were correlated with dream features in natural sleep.

Methods

Fifty-one patients, undergoing surgical excision of fibroadenomas under a Bispectral index-guided deep sedation anesthesia with propofol target controlled infusion, were enrolled into this prospective study. Psychological assessment was performed through the State Trait Anxiety Inventory. A questionnaire was adopted to register dreaming and anesthesia awareness. Data were collected after emergence (t0), 24 hours (t1), 1 month (t2), 6 months (t3).

Results

Six patients (12%) reported anesthetic dreaming at t0 confirming the response at each subsequent evaluation. One patient (2%) confirmed dreaming during anesthesia in all, but denied it at t0. There was a high correlation between the intraoperative dream contents and the features of dreams in natural sleep. No cases of anesthesia awareness were detected. A similar level of satisfaction was observed in dreaming and no-dreaming patients.

Conclusions

Anesthetic dreaming does not seem to influence satisfaction of patients undergoing deep sedation with propofol target controlled infusion. A psychological assessment would seem to improve the evaluation of possible psychological consequences in dreamer patient.

5th National Audit Project (NAP5) on accidental awareness during general anaesthesia: patient experiences, human factors, sedation, consent, and medicolegal issues

The 5th National Audit Project (NAP5) of the Royal College of Anaesthetists and the Association of Anaesthetists of Great Britain and Ireland into accidental awareness during general anaesthesia (AAGA) yielded data related to psychological aspects from the patient, and the anaesthetist, perspectives; patients' experiences ranged from isolated auditory or tactile sensations to complete awareness. A striking finding was that 75% of experiences were for <5 min, yet 51% of patients [95% confidence interval (CI) 43-60%] experienced distress and 41% (95% CI 33-50%) suffered longer term adverse effect. Distress and longer term harm occurred across the full range of experiences but were particularly likely when the patient experienced paralysis (with or without pain). The patient's interpretation of what is happening at the time of the awareness seemed central to later impact; explanation and reassurance during suspected AAGA or at the time of report seemed beneficial. Quality of care before the event was judged good in 26%, poor in 39%, and mixed in 31%. Three-quarters of cases of AAGA (75%) were judged preventable. In 12%, AAGA care was judged good and the episode not preventable. The contributory and human factors in the genesis of the majority of cases of AAGA included medication, patient, and education/training. The findings have implications for national guidance, institutional organization, and individual practice. The incidence of 'accidental awareness' during sedation (~1:15,000) was similar to that during general anaesthesia (~1:19,000). The project raises significant issues about information giving and consent for both sedation and anaesthesia. We propose a novel approach to describing sedation from the patient's perspective which could be used in communication and consent. Eight (6%) of the patients had resorted to legal action (12, 11%, to formal complaint) at the time of reporting. NAP5 methodology provides a standardized template that might usefully inform the investigation of claims or serious incidents related to AAGA.

Acceptably aware during general anaesthesia: 'dysanaesthesia'--the uncoupling of perception from sensory inputs

This review makes the case for 'dysanaesthesia', a term encompassing states of mind that can arise in the course of anaesthesia during surgery, characterised by an uncoupling of sensation and perceptual experience. This is reflected in a macroscopic, functional model of anaesthetically-relevant consciousness. Patients in this state can be aware of events but in a neutral way, not in pain, sometimes personally dissociated from the experiences. This makes events associated with surgery peripheral to their whole experience, such that recall is less likely and if it exists, makes any spontaneous report of awareness unlikely. This state of perception-sensation uncoupling is therefore broadly acceptable (a minimum requirement for acceptable anaesthesia) but since it is likely a dose-related phenomenon, may also represent a precursor for awareness with adverse recall. This hypothesis uniquely explains the often inconsistent responses seen during the experimental paradigm of the 'isolated forearm technique', wherein apparently anaesthetised patients exhibit a positive motor response to verbal command, but no spontaneous movement to surgery. The hypothesis can also explain the relatively high incidence of positive response to relatively direct questions for recall (e.g., using the Brice questionnaire; ∼1:500; the vast majority of these being neutral reports) versus the very low incidence of spontaneous reports of awareness (∼1:15,000; a higher proportion of these being adverse recollections). The hypothesis is consistent with relevant notions from philosophical discussions of consciousness, and neuroscientific evidence. Dysanaesthesia has important implications for research and also for the development of appropriate monitoring.