Dreaming in Sedation During Spinal Anesthesia: A Comparison of Propofol and Midazolam Infusion

Dreaming during gastrointestinal endoscopy under propofol, ciprofol, or remimazolam anesthesia: study protocol for a parallel-design double-blind, single-center trial

BACKGROUND

Dreaming sometimes occurs during sedation. It has been reported that factors such as different anesthetics, depth of anesthesia, age, sex, and preoperative psychological state may affect dreams. Ciprofol and remimazolam are novel choices for painless endoscopy. Herein, we aimed to investigate dreaming during gastrointestinal endoscopy under propofol, ciprofol, and remimazolam anesthesia respectively.

METHODS

This is a prospective, parallel-design double-blind, single-center clinical trial. Three hundred and sixty subjects undergoing elective painless gastroscopy, colonoscopy, or gastroenteroscopy will be enrolled. Eligible subjects will undergo propofol-, ciprofol-, or remimazolam-induced anesthesia to finish the examination. Interviews about the modified Brice questionnaire will be conducted in the recovery room. Incidence of dreaming is set as the primary outcome. Secondary outcomes include type of dreams, improvement of sleep quality, evaluation of patients, incidence of insufficient anesthesia, and intraoperative awareness. Safety outcomes are the incidences of hypotension and hypoxia during examination and adverse events during recovery.

DISCUSSION

This study may observe different incidences of dreaming and diverse types of dreams, which might lead to different evaluations to the anesthesia procedure. Based on the coming results, anesthesiologists can make a better medication plan for patients who are going to undergo painless diagnosis and treatment.

TRIAL REGISTRATION

This trial was registered at the Chinese Clinical Trial Registry on May 18, 2023 (registration number ChiCTR2300071565).

Subjective experiences during dexmedetomidine- or propofol-induced unresponsiveness and non-rapid eye movement sleep in healthy male subjects

BACKGROUND

Anaesthetic-induced unresponsiveness and non-rapid eye movement (NREM) sleep share common neural pathways and neurophysiological features. We hypothesised that these states bear resemblance also at the experiential level.

METHODS

We compared, in a within-subject design, the prevalence and content of experiences in reports obtained after anaesthetic-induced unresponsiveness and NREM sleep. Healthy males (N=39) received dexmedetomidine (n=20) or propofol (n=19) in stepwise doses to induce unresponsiveness. Those rousable were interviewed and left unstimulated, and the procedure was repeated. Finally, the anaesthetic dose was increased 50%, and the participants were interviewed after recovery. The same participants (N=37) were also later interviewed after NREM sleep awakenings.

RESULTS

Most subjects were rousable, with no difference between anaesthetic agents (P=0.480). Lower drug plasma concentrations were associated with being rousable for both dexmedetomidine (P=0.007) and propofol (P=0.002) but not with recall of experiences in either drug group (dexmedetomidine: P=0.543; propofol: P=0.460). Of the 76 and 73 interviews performed after anaesthetic-induced unresponsiveness and NREM sleep, 69.7% and 64.4% included experiences, respectively. Recall did not differ between anaesthetic-induced unresponsiveness and NREM sleep (P=0.581), or between dexmedetomidine and propofol in any of the three awakening rounds (P>0.05). Disconnected dream-like experiences (62.3% vs 51.1%; P=0.418) and memory incorporation of the research setting (88.7% vs 78.7%; P=0.204) were equally often present in anaesthesia and sleep interviews, respectively, whereas awareness, signifying connected consciousness, was rarely reported in either state.

CONCLUSIONS

Anaesthetic-induced unresponsiveness and NREM sleep are characterised by disconnected conscious experiences with corresponding recall frequencies and content.

CLINICAL TRIAL REGISTRATION

Clinical trial registration. This study was part of a larger study registered at ClinicalTrials.gov (NCT01889004).

Risk factors for dexmedetomidine-associated bradycardia during spinal anesthesia: A retrospective study

Sedation with dexmedetomidine is needed for patients undergoing spinal anesthesia. However, dexmedetomidine sedation increases the incidence of bradycardia. We aimed to identify and to evaluate risk factors for bradycardia in patients undergoing spinal anesthesia with dexmedetomidine sedation. The records of 91 patients who underwent spinal anesthesia with sedation using dexmedetomidine were reviewed retrospectively. For this study, we identified 15 characteristics of included patients from this group who underwent lower leg surgery and had an estimated blood loss of <300 mL. We collected details on potential risk factors for bradycardia from their clinical records. These factors included age, American Society of Anesthesiologists classification, height, weight, sensory level of spinal anesthesia, history of hypertension, diabetes mellitus, loading, and maintenance dose of dexmedetomidine, tourniquet time, initial diastolic and systolic blood pressure, initial heart rate (HR), and anesthesia and surgery duration. The primary endpoint of this study was the occurrence of bradycardia. We identified potential risk factors using logistic regression analysis. The incidence of bradycardia was obtained in 23 (25%) of 91 patients. Initial HR and tourniquet time were significant individual predictive factors for the occurrence of bradycardia. Logistic regression analysis showed that adjusted baseline HR and duration of tourniquet use were risk factors for bradycardia. Patients should be monitored when undergoing spinal anesthesia with sedation using dexmedetomidine for bradycardia when they have a long tourniquet time. A low initial HR could also be a predictive factor for bradycardia.

On no man's land: Subjective experiences during unresponsive and responsive sedative states induced by four different anesthetic agents

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.

Psychological impact of unexpected explicit recall of events occurring during surgery performed under sedation, regional anaesthesia, and general anaesthesia: data from the Anesthesia Awareness Registry

BACKGROUND

Anaesthetic awareness is a recognized complication of general anaesthesia (GA) and is associated with post-traumatic stress disorder (PTSD). Although complete amnesia for intraprocedural events during sedation and regional anaesthesia (RA) may occur, explicit recall is expected by anaesthesia providers. Consequently, the possibility that there could be psychological consequences associated with unexpected explicit recall of events during sedation and RA has not been investigated. This study investigated the psychological sequelae of unexpected explicit recall of events during sedation/RA that was reported to the Anesthesia Awareness Registry.

METHODS

The Registry recruited subjects who self-identified as having had anaesthetic awareness. Inclusion criteria were a patient-reported awareness experience in 1990 or later and availability of medical records. The sensations experienced by the subjects during their procedure and the acute and persistent psychological sequelae attributed to this explicit recall were assessed for patients receiving sedation/RA and those receiving GA.

RESULTS

Among the patients fulfilling the inclusion criteria, medical record review identified 27 sedation/RA and 50 GA cases. Most patients experienced distress (78% of sedation/RA vs 94% of GA). Approximately 40% of patients with sedation/RA had persistent psychological sequelae, similar to GA patients. Some sedation/RA patients reported an adverse impact on their job performance (15%), family relationships (11%), and friendships (11%), and 15% reported being diagnosed with PTSD.

CONCLUSIONS

Patients who self-reported to the Registry unexpected explicit recall of events during sedation/RA experienced distress and persistent psychological sequelae comparable with those who had reported anaesthetic awareness during GA. Further study is warranted to determine if patients reporting distress with explicit recall after sedation/RA require psychiatric follow-up.

Ketamine/propofol admixture (ketofol) is associated with improved hemodynamics as an induction agent: a randomized, controlled trial

BACKGROUND

Critically ill patients may require emergent intubations, and the use of some induction agents can lead to undesirable effects on hemodynamics. The use of "ketofol" (ketamine/propofol admixture) may allow for improved hemodynamic control. The primary aim of this study was to assess the hemodynamic effects of "ketofol" in a fixed-dose combination during induction of general anesthesia in a controlled environment.

METHODS

This was a randomized, double-blinded, placebo-controlled trial conducted at the Dartmouth Hitchcock Medical Center. American Society of Anesthesiology physical status I and II patients undergoing general anesthesia were randomly assigned to standardized induction with propofol alone or with "ketofol." Baseline noninvasive hemodynamic measurements were obtained and continuously monitored throughout the study period. Our hypothesis assumed that "ketofol" as an induction alternative would produce stable hemodynamics as referenced from baseline compared with propofol alone. The primary outcome was a systematic randomized assessment of changes in systolic blood pressure from baseline measurements for 30 minutes after induction. The primary comparisons were the frequency of a 20% change in systolic blood pressure at 5 minutes, 10 minutes, and 30 minutes after induction.

RESULTS

Baseline patient demographics and intraoperative characteristics were equivalent in both groups. Propofol was more likely to generate a 20% reduction in systolic blood pressure from baseline at 5 minutes (48.8% vs. 12%, odds ratio: 6.87, 95% confidence interval: 2.07-26.15, p = < 0.001) and 10 minutes (67.4% vs. 39%, odds ratio: 3.24, 95% confidence interval: 1.21-8.75, p = < 0.01) as compared with "ketofol." This difference remained significant after adjustment for potentially confounding variables.

CONCLUSION

"Ketofol" is associated with improved hemodynamic stability during the first 10 minutes after induction. Further study is needed to assess the efficacy of "ketofol" in critically ill patients and those with significant comorbidities. This combination has the potential to be used as an alternative agent for emergency induction during which time stable hemodynamics are desirable.

Dreaming during sevoflurane or propofol short-term sedation: a randomised controlled trial

Prior reports suggest that dreaming during anaesthesia is dependent on recovery time. Dreaming during sedation may impact patient satisfaction. The current study explores the incidence and content of dreaming during short-term sedation with sevoflurane or propofol and investigates whether dreaming is affected by recovery time. A total of 200 women undergoing first trimester abortion (American Society of Anesthesiologists physical status I) participated in the study. Patients were randomly assigned to receive either sevoflurane or propofol for short-term sedation. Patients were interviewed upon emergence with the modified Brice questionnaire. The results showed the incidence of dreaming was significantly different between anaesthesia groups with 60% (60/100) of the sevoflurane group and 33% (33/100) of the propofol group (P=0.000). However, recovery time did not significantly differ between groups. In the sevoflurane group, a greater number of dreamers could not recall what they had dreamed about (P=0.02) and more patients reported dreams that had no sound (P=0.03) or movement (P=0.001) compared with dreamers in the propofol group. Most participants reported dreams with positive emotional content and this did not significantly differ between groups. Anaesthesia administered had no effect on patient satisfaction. The results suggest that the incidence of dreaming was not affected by recovery time. Patient satisfaction was not influenced by choice of sedative and/or by the occurrence of dreaming during sevoflurane or propofol short-term sedation.