Study protocol: Cerebral characterization of sensory gating in disconnected dreaming states during propofol anesthesia using fMRI.

Background: Disconnected consciousness describes a state in which subjective experience (i.e., consciousness) becomes isolated from the external world. It appears frequently during sleep or sedation, when subjective experiences remain vivid but are unaffected by external stimuli. Traditional methods of differentiating connected and disconnected consciousness, such as relying on behavioral responsiveness or on post-anesthesia reports, have demonstrated limited accuracy: unresponsiveness has been shown to not necessarily equate to unconsciousness and amnesic effects of anesthesia and sleep can impair explicit recollection of events occurred during sleep/sedation. Due to these methodological challenges, our understanding of the neural mechanisms underlying sensory disconnection remains limited. Methods: To overcome these methodological challenges, we employ a distinctive strategy by combining a serial awakening paradigm with auditory stimulation during mild propofol sedation. While under sedation, participants are systematically exposed to auditory stimuli and questioned about their subjective experience (to assess consciousness) and their awareness of the sounds (to evaluate connectedness/disconnectedness from the environment). The data collected through interviews are used to categorize participants into connected and disconnected consciousness states. This method circumvents the requirement for responsiveness in assessing consciousness and mitigates amnesic effects of anesthesia as participants are questioned while still under sedation. Functional MRI data are concurrently collected to investigate cerebral activity patterns during connected and disconnected states, to elucidate sensory disconnection neural gating mechanisms. We examine whether this gating mechanism resides at the thalamic level or results from disruptions in information propagation to higher cortices. Furthermore, we explore the potential role of slow-wave activity (SWA) in inducing disconnected consciousness by quantifying high-frequency BOLD oscillations, a known correlate of slow-wave activity. Discussion: This study represents a notable advancement in the investigation of sensory disconnection. The serial awakening paradigm effectively mitigates amnesic effects by collecting reports immediately after regaining responsiveness, while still under sedation. Ultimately, this research holds the potential to understand how sensory gating is achieved at the neural level. These biomarkers might be relevant for the development of sensitive anesthesia monitoring to avoid intraoperative connected consciousness and for the assessment of patients suffering from pathologically reduced consciousness. Clinical trial registration: European Union Drug Regulating Authorities Clinical Trials Database (EudraCT), identifier 2020-003524-17.

Propofol sedation in routine endoscopy: A case series comparing target controlled infusion vs manually controlled bolus concept.

BACKGROUND: Many studies have addressed safety and effectiveness of non-anaesthesiologist propofol sedation (NAPS) for gastrointestinal (GI) endoscopy Target controlled infusion (TCI) is claimed to provide an optimal sedation regimen by avoiding under- or oversedation. AIM: To assess safety and performance of propofol TCI sedation in comparison with nurse-administered bolus-sedation. METHODS: Fouty-five patients undergoing endoscopy under TCI propofol sedation were prospectively included from November 2016 to May 2017 and compared to 87 patients retrospectively included that underwent endoscopy with NAPS. Patients were matched for age and endoscopic procedure. We recorded time of sedation and endoscopy, dosage of medication and adverse events. RESULTS: There was a significant reduction in dose per time of propofol administered in the TCI group, compared to the NAPS group (8.2 ± 2.7 mg/min vs 9.3 ± 3.4 mg/min; P = 0.046). The time needed to provide adequate sedation levels was slightly but significantly lower in the control group (5.3 ± 2.7 min vs 7.7 ± 3.3 min; P < 0.001), nonetheless the total endoscopy time was similar in both groups. No differences between TCI and bolus-sedation was observed for mean total-dosage of propofol rate as well as adverse events. CONCLUSION: This study indicates that sedation using TCI for GI endoscopy reduces the dose of propofol necessary per minute of endoscopy. This may translate into less adverse events. However, further and randomized trials need to confirm this trend.

Recovery of driving skills after endoscopy under propofol sedation: a prospective pilot study to assess the driving skills after endoscopic sedation using driving simulation.

BACKGROUND: Patients are recommended not to drive for at least the first 24 h after endoscopy with propofol sedation. However, the evidence underlying these recommendations is scarce. We hypothesized that after endoscopic procedures performed under propofol sedation, the subject's driving ability was restored in less than 24 h. METHODS: We prospectively enrolled thirty patients between 20 and 70 years possessing a legitimate driver's license scheduled for endoscopy at our hospital. The sample chosen was a convenience sample. Gastroscopy or colonoscopy was performed with propofol sedation. Before and after endoscopy, the investigator drove the subjects to the laboratory to assess their driving skills using a driving simulation system, which employs 3 driving scenarios designed by professional transportation researchers. The blood propofol concentration was estimated before endoscopy, and 2 and 4 h after endoscopy. The primary outcome was the time required for subjects to recover their driving ability after propofol sedation. The secondary outcome was the blood propofol concentration before and after endoscopic procedures under propofol anesthesia. RESULTS: Thirty volunteers participated in the study and 18 of them completed all the interventions. In the low-risk S-curve scene, the mean acceleration, lane deviation, and number of deviations from the path at baseline (0.016 cm/s2, 42.50 cm, and 0.83, respectively) were significantly less than that at post-2 h (0.029 cm/s2, P = 0.001; 53.80 cm, P = 0.014; 2.06, P = 0.022). In the moderate-(overtaking) and high-risk (emergency collision avoidance) scenes, the tested parameters at baseline and post-2 h were statistically comparable. In the low-, moderate-, and high-risk scenes the tested parameters at baseline and post-4 h were statistically comparable. The total range of propofol was 120-280 mg.The mean blood concentration of propofol at post-2 h was 0.81 ± 0.40 µg/mL, and at post-4 h was below the limit of detection. CONCLUSION: After endoscopy performed under propofol sedation, subjects' driving abilities were completely restored at 4 h when tested on a simulator.

To ascertain the plasma concentration of propofol to achieve bispectral index-guided sedation using a target-controlled infusion in patients undergoing elective surgeries under neuraxial anaesthesia.

Background and Aims: Sedation improves patient satisfaction, comfort and acceptance of regional anaesthesia. Propofol using bispectral index (BIS)/target-controlled infusion (TCI) system can be an optimal method of sedation, as it combines objective measurement of sedation using BIS along with maintenance of a steady plasma concentration of propofol with the TCI device. The aim of this study was to ascertain the dose and safety of propofol using BIS/TCI system for sedation in patients undergoing surgeries under neuraxial anaesthesia. Methods: One hundred and seven adult patients, undergoing elective surgical procedures under spinal or combined spinal epidural anaesthesia, were recruited. Propofol infusion was started with TCI at an initial target plasma concentration (Cpt) of 1.2 µg/mL, and after equilibration between Cpt and effect site concentration (Ce), propofol was then adjusted in increments and/or decrements of 0.2 µg/mL in order to maintain a BIS value between 60 and 80. The average time to reach BIS = 80 after starting infusion was 7.32 ± 3.13 minutes. The objective was to calculate mean Cpt value maintaining BIS between 60 and 80 and to observe recovery time and complications. Results: Mean Cpt value was 1.13 ± 0.17 mg/mL with 95% confidence interval (1.10-1.16 µg/mL). In 85% of patients, a BIS value of 60-80 was maintained at Cpt ≤ 1.2 µg/mL. No patient had severe complications requiring stoppage of infusion. Conclusion: Propofol sedation using BIS/TCI system can provide safe and convenient sedation during neuraxial anaesthesia at very low plasma concentration, Cpt ≤ 1.2 µg/mL in majority of patients. There were no periprocedural complications, and recovery was rapid.

Patient Satisfaction of Propofol Versus Midazolam and Fentanyl Sedation During Colonoscopy in Inflammatory Bowel Disease.

BACKGROUND & AIMS: Colonoscopy is essential for optimal management of inflammatory bowel disease. However, many patients opt out due to unpleasantness related to this procedure. We investigated if Nurse Administered Propofol Sedation (NAPS) would improve patient satisfaction and attitude towards future colonoscopies. METHODS: Randomized clinical trial of deep sedation with NAPS (n = 63) versus moderate midazolam and fentanyl sedation (n = 67). To assess the primary end point of patient satisfaction at discharge, we developed a Satisfaction Questionnaire comprising 13 items each rated by a 5-point Likert scale and with higher scores reflecting more positive outcomes (13-65 points). RESULTS: Fifty-six patients (43%) with ulcerative colitis, 48 (37%) with Crohn's disease, and 26 (20%) with high suspicion of inflammatory bowel disease were included. Most (88%) had previously had a colonoscopy and pre-procedure expectations were similar between groups. Patients receiving deep sedation had significantly higher satisfaction score (mean 60.1, SD 3.4) than those receiving moderate sedation (51.2, 8.4; P < .001). This was driven especially by less pain, more amnesia, sedation more to their liking, and better experience with the current than previous sedations. Importantly, these patients significantly more often preferred the same sedation for a future colonoscopy and were also inclined to accept more frequent colonoscopies. Assistance from another colonoscopist and disruption of the procedure due to pain occurred significantly more frequent in the moderate sedation group. There were no safety signals associated with NAPS. CONCLUSIONS: Patients with inflammatory bowel disease favor deep propofol sedation over moderate midazolam and fentanyl sedation. Availability of NAPS may facilitate patient adherence to endoscopy-based monitoring programs. Clinicaltrials.gov NCT01934088.

Impact of High-Flow Nasal Cannula Oxygenation on the Prevention of Hypoxia During Endoscopic Retrograde Cholangiopancreatography in Elderly Patients: A Randomized Clinical Trial.

BACKGROUND: Hypoxia is the most frequently occurring adverse effect during endoscopic retrograde cholangiopancreatography (ERCP) under sedation; thus, oxygen must be properly supplied to prevent a reduction of oxygen saturation. In this study, we intend to verify the preventive effect for hypoxia during ERCP, using a high-flow nasal cannula (HFNC), in elderly patients. METHODS: As a multicenter prospective randomized trial, patients who underwent ERCP with propofol-based sedation were randomly assigned into two groups: Patients in the HFNC group were supplied with oxygen via an HFNC, and those in the standard nasal cannula group were supplied with oxygen via a low-flow nasal cannula. The co-primary end points were the lowest oxygen saturation rate and hypoxia during the overall procedure. RESULTS: A total of 187 patients (HFNC group: 95; standard nasal cannula group: 92) were included in the analysis. Unexpected hypoxia events were more frequently observed among patients in the standard nasal cannula group than among patients in the HFNC group (13% vs. 4%, odds ratio 3.41, 95% confidence interval 1.06-11.00, p = 0.031). The mean of the lowest oxygen saturation rate during ERCP was significantly lower in the standard nasal cannula group than in the HFNC group (95% vs. 97%, p = 0.002). CONCLUSION: Oxygen supplementation with an HFNC can prevent oxygen desaturation and hypoxia events in patients undergoing ERCP under sedation. Trial registration Clinical Research Information Service (CRIS; KCT0004960).

Capability of processed EEG parameters to monitor conscious sedation in endoscopy is similar to general anaesthesia.

BACKGROUND: Reliable and safe sedation is a prerequisite for endoscopic interventions. The current standard is rather safe, yet, an objective device to measure sedation depth is missing. To date, anaesthesia monitors based on processed electroencephalogram (EEG) have not been utilised in conscious sedation. OBJECTIVE: To investigate EEG parameters to differentiate consciousness in endoscopic propofol sedation. METHODS: In total, 171 patients aged 21-83 years (ASA I-III) undergoing gastrointestinal and bronchial endoscopy were enrolled. Standard monitoring and a frontotemporal two-channel EEG were recorded. The state of consciousness was identified by repeated requests to squeeze the investigator's hand. RESULTS: In total, 1132 state-of-consciousness (SOC) transitions were recorded in procedures ranging from 5 to 69 min. Thirty-four EEG parameters from the frequency domain, time-frequency domain and complexity measures were calculated. Area under the curve ranged from 0.51 to 0.82 with complexity and optimised frequency domain parameters yielding the best results. CONCLUSION: Prediction of the SOC with processed EEG parameters is feasible, and the results for sedation in endoscopic procedures are similar to those reported from general anaesthesia. These results are insufficient for a clinical application, but prediction capability may be increased with optimisation and modelling.

Use of noninvasive positive pressure ventilation in patients with severe obesity undergoing esophagogastroduodenoscopy: a randomized controlled trial.

BACKGROUND: Patients with severe obesity being considered for bariatric surgery often undergo preoperative esophagogastroduodenoscopy (EGD). Severe obesity is a risk factor for oxygen desaturation events during EGD. The use of noninvasive positive pressure ventilation (NIPPV) to reduce desaturation events during EGD among patients with severe obesity has not been studied. OBJECTIVE: To evaluate the use of NIPPV among patients with severe obesity undergoing EGD. SETTING: Community hospital endoscopy suite. METHODS: A randomized controlled trial evaluated the use of NIPPV in patients with severe obesity undergoing EGD. Patients were randomized into treatment (NIPPV) and control (nasal cannula, NIPPV for rescue) groups. Primary endpoints were oxygen desaturation events ≤94% and oxygen desaturation events <90% requiring intervention. A secondary endpoint was the use of NIPPV as a rescue maneuver. RESULTS: Fifty-six patients with a body mass index of 40 to 60 were randomized (n = 28 treatment and n = 28 control). A statistically significant difference was noted between the groups for desaturation events ≤94% (14.3% of treatment and 57.1% of control groups, P = .002). There was also a statistically significant difference in the risk of a desaturation event <90% requiring intervention (3.5% of treatment and 28.6% of control groups, P = .025). All patients in the control group who developed desaturation events requiring intervention were rescued with NIPPV. CONCLUSIONS: This study demonstrated the successful use of NIPPV as an adjunct to decrease the incidence of desaturation events in patients with severe obesity undergoing EGD.

Propofol Compared to Midazolam Sedation and to General Anesthesia for Percutaneous Microwave Ablation in Patients with Hepatic Malignancies: A Single-Center Comparative Analysis of Three Historical Cohorts.

PURPOSE: In percutaneous ablation procedures, periprocedural pain, unrest and respiratory concerns can be detrimental to achieve a safe and efficacious ablation and impair treatment outcome. This study aimed to compare the association between anesthetic technique and local disease control in patients undergoing percutaneous microwave ablation (MWA) of colorectal liver metastases (CRLM) and hepatocellular carcinoma (HCC). MATERIALS AND METHODS: This IRB-exempted single-center comparative, retrospective analysis of three cohorts analyzed 90 patients treated for hepatic malignancies from January 2013 until September 2018. The local tumor progression-free survival (LTPFS), safety and periprocedural pain perception were assessed using univariate and multivariate Cox proportional hazard regression analyses to correct for potential confounders. RESULTS: In 114 procedures (22 general anesthesia; 32 midazolam; 60 propofol), 171 liver tumors (136 CRLM; 35 HCC) were treated with percutaneous MWA. Propofol and general anesthesia were superior to midazolam/fentanyl sedation regarding LTPFS (4/94 [4.3%] vs. 19/42 [45.2%] vs. 2/35 [5.7%]; P < 0.001, respectively). Local tumor progression rate was 14.6% (25/171). Eighteen tumors (72.0%) were retreated by ablation. Of them, 14 (78%) were previously treated with midazolam. Propofol versus midazolam (P < 0.001), general anesthesia versus midazolam (P = 0.016), direct postprocedural visual analog pain score above 5 (P = 0.050) and more than one tumor per procedure (P = 0.045) were predictors for LTPFS. Multivariate analysis revealed that propofol versus midazolam (HR 7.94 [95% CI 0.04-0.39; P < 0.001]) and general anesthesia versus midazolam (HR 6.33 [95% CI 0.04-0.69; P = 0.014]) were associated with LTPFS. Pain during and directly after treatment was significantly worse in patients who received midazolam sedation (P < 0.001). CONCLUSIONS: Compared to propofol and general anesthesia, midazolam/fentanyl sedation was associated with an increased periprocedural perception of pain and lower local tumor progression-free survival. To reduce the number of repeat procedures required to eradicate hepatic malignancies, general anesthesia and propofol sedation should be favored over midazolam.

A Prototype Patient-Maintained Propofol Sedation System Using Target Controlled Infusion for Primary Lower-Limb Arthroplasty.

Each year, many operations in the UK are performed with the patient awake, without the use of general anaesthesia. These include joint replacement procedures, and in order to reduce patient anxiety, the supervising anaesthetist delivers the sedative propofol intravenously using a target-controlled infusion (TCI) device. However, it is clinically challenging to judge the required effect-site concentration of sedative for an individual patient, resulting in patient care issues related to over or under-sedation. To improve the process, patient-maintained propofol sedation (PMPS), where the patient can request an increase in concentration through a hand-held button, has been considered as an alternative. However, due to the proprietary nature of modern TCI pumps, the majority of PMPS research has been conducted using prototypes in research studies. In this work, a PMPS system is presented that effectively converts a standard infusion pump into a TCI device using a laptop with TCI software. Functionally, the system delivers sedation analogous to a modern TCI pump, with the differences in propofol consumption and dosage within the tolerance of clinically approved devices. Therefore, the Medicines and Healthcare products Regulatory Agency (MHRA) has approved the system as a safe alternative to anaesthetist-controlled TCI procedures. It represents a step forward in the consideration of PMPS as a sedation method as viable alternative, allowing further assessment in clinical trials.

Seguridad de la sedación con propofol administrado por gastroenterólogos en endoscopia digestiva / Safety of propofol sedation administered by gastroenterologists in digestive endoscopy

Resumen Objetivo: tradicionalmente, la sedación con propofol ha estado a cargo de especialistas en anestesiología; sin embargo, una extensa cantidad de información publicada ha demostrado que la sedación con propofol administrado por no anestesiólogos, es segura y eficaz. El estudio se realizó con el objetivo de evaluar la seguridad en la administración de propofol por gastroenterólogos, para la realización de procedimientos en endoscopia digestiva. Métodos: se hizo un estudio retrospectivo en el cual se revisaron los expedientes de 1135 pacientes sometidos a endoscopias digestivas diagnósticas y terapéuticas, en el período comprendido entre enero de 2016 y marzo de 2017. Los pacientes se organizaron por su: edad, género, clasificación de riesgo de la Sociedad Americana de Anestesiólogos, indicación para la endoscopia, y dosis utilizada de propofol. Se registraron los efectos adversos asociados al uso de Propofol, tales como: episodios de hipoxemia transitoria, complicaciones cardiopulmonares serias y muerte. Resultados: se incluyeron los datos de 1135 pacientes (56 % fueron mujeres) que se practicaron endoscopia digestiva bajo sedación con propofol administrado por gastroenterólogos, en un período de 14 meses. La dosis promedio utilizada de propofol fue de 154 +/- 66 mg. Según la clasificación de riesgo de la Sociedad Americana de Anestesiólogos, el 84 % de los pacientes corresponde a las clasificaciones I y II, un 14,8 % a pacientes con clasificación de riesgo III y un 1,1 %, riesgo IV. Los estudios efectuados fueron mayoritariamente gastroscopias (52,6 %) y según la indicación, el 79,6 % corresponde a estudios diagnósticos, seguido de un 12,1% para los sangrados digestivos altos de emergencia. En cuanto a las complicaciones documentadas, se identificaron 70 episodios de hipoxemia que corresponden a un 6,2 % de las sedaciones realizadas. (IC 95%, 4,7-7,6). Solamente un 3,7 % de los pacientes presentó un episodio de hipoxemia por debajo del 80 %. Todos los episodios de hipoxemia, excepto uno, resolvieron con maniobras simples, como la elevación del mentón. Durante el estudio no se presentaron complicaciones cardiopulmonares serias o muertes. Se identificaron, como factores de riesgo para la aparición de hipoxemia, una clasificación de riesgo de la Sociedad Americana de Anestesiólogos mayor a 3, y la realización del estudio endoscópico para dilatación esofágica o colocación de gastrostomía percutánea. Conclusiones: el uso de sedación con propofol administrado por no anestesiólogos en el estudio, no evidenció incremento en la aparición de complicaciones cardiopulmonares serias, ni en los episodios de hipoxemia.

Abstract Aim: Traditionally, sedation with propofol has been approved exclusively for use by anethesiologists, however, an extensive amount of published information has shown that sedation with propofol administered by non-anesthesiologists is safe and effective. The present study was conducted with the objective of evaluating the safety in the administration of propofol by gastroenterologists for the performance of procedures in digestive endoscopy. Methods: A retrospective study was conducted in which the records of 1135 patients who underwent digestive and therapeutic digestive endoscopies were reviewed in the period between January 2016 and March 2017. The patients were classified by age, gender, risk classification of the American Society of Anesthesiologists (ASA), indication for endoscopy, and dose of propofol. The adverse effects associated with the use of propofol were recorded, such as episodes of transient hypoxemia, serious cardiopulmonary complications and death. Results: We included data from 1135 patients (56% were women) who underwent gastrointestinal endoscopy under sedation with propofol administered by gastroenterologist in a period of 14 months. The average dose used for propofol was 154 +/- 66 mg of propofol. According to the American Society of Anesthesiologists risk classification, 84% of the patients correspond to risk I and II, 14.8% to risk level III and 1.1% to risk level IV. The study carried out the most were gastroscopies (52.6%) and according to the indication, 79.6% corresponded to diagnostic studies, followed by 12.1% for upper gastrointestinal bleeding. Regarding the documented complications,70 episodes of hypoxemia were identified, corresponding to 6.2% of the sedations performed. (95% CI, 4.7-7.6). Only 3.7% of patients had an episode of hypoxemia below 80%. All episodes of hypoxemia, except one, resolved with simple maneuvers such as chin elevation. There were no serious cardiopulmonary complications or deaths during the study. We identified as risk factors for the appearance of hypoxemia a risk classification of the American Society of Anesthesiologists greater than 3 and performance of the endoscopic study for esophageal dilation or percutaneous gastrostomy placement. Conclusions: The use of sedation with propofol administered by non-anesthesiologists in the present study did not show an increase in the appearance of serious cardiopulmonary complications, or in episodes of hypoxemia.

Safety and efficacy of endoscopist-directed balanced propofol sedation during endoscopic retrograde cholangiopancreatography.

BACKGROUND: Endoscopist-directed balanced propofol sedation (BPS) appears to be safe and effective for routine endoscopy. However, there are limited data on its use in endoscopic retrograde cholangiopancreatography (ERCP). We evaluated the safety and efficacy of endoscopist-directed BPS for ERCP, and compared patient outcomes with anesthesiologist-administered moderate sedation. METHODS: This was a retrospective cohort study, using prospectively collected endoscopy data from a tertiary care medical center where endoscopist-directed BPS during ERCP is routine practice. Adverse outcomes included need for bag-mask ventilation or intubation, aborted ERCP due to sedation, hospital admission post-ERCP (outpatients)/change in the level of care (inpatients), and death within 24 h. RESULTS: A total of 501 patients underwent ERCP with the use of endoscopist-directed BPS: Cohort 1 - 380 (76%) inpatients, mean age 64.1, 46% male, 24% American Society of Anesthesiologists physical status (ASA) score I, 65% ASA II, 11% ASA III. Concurrently, 24 patients received anesthesiologist-administered moderate sedation: Cohort 2 - 19 (79%) inpatients, mean age 65.0, 67% male, 12% ASA I, 25% ASA II, 38% ASA III, 25% ASA IV. In Cohort 1, none of the adverse outcomes were observed. Propofol dose was inversely correlated with age (r=-0.42, P<0.001), ASA score (r=-0.19, P<0.001), and Mallampati score (r=-0.24, P<0.001). One patient in Cohort 2 who received anesthesiologist-administered BPS required bag-mask ventilation and the ERCP was prematurely aborted because of the sedation. There were no deaths from any cause within 24 h of ERCP. CONCLUSION: Endoscopist-directed BPS appears safe, efficacious, and feasible for ASA I-III patients undergoing inpatient or ambulatory ERCP.

Propofol sedation without endotracheal intubation is safe for endoscopic submucosal dissection in the esophagus and stomach.

Background: Endoscopic submucosal dissection (ESD) for early esophageal and stomach cancer is usually performed under general anesthesia. However, propofol sedation without endotracheal intubation has been suggested as a viable alternative. Objective: The objective of this study was to evaluate the safety of propofol sedation without endotracheal intubation during ESD in the upper gastrointestinal tract. Methods: We performed a retrospective cohort study of patients who underwent ESD for upper gastrointestinal tumors with propofol-remifentanil analgosedation in a tertiary referral center in the Netherlands between October 2013 and February 2018. Primary endpoints were the rates of intraprocedural endoscopy- and anesthesia-related complications. Secondary endpoints were the postprocedural complication rates within 30 days and endotracheal intubation conversion rates. Results: Of 88 patients, intraprocedural ESD-related complications occurred in three patients (3.4%). Intraprocedural anesthesia-related complications occurred in two patients (2.3%), one of whom required conversion to endotracheal intubation. Postprocedural ESD-related complications occurred in 14 patients (15.9%), and minor postprocedural complications occurred in two patients (2.3%). Eighty-two (93.2%) patients were discharged within one day after ESD. No patient was readmitted for anesthesia-related complications. Conclusion: Propofol-based sedation without endotracheal intubation is safe for ESD procedures in the esophagus and stomach with low anesthesia-related complication rates and short hospital stay.

Anaesthetist-controlled versus patient-maintained effect-site targeted propofol sedation during elective primary lower-limb arthroplasty performed under spinal anaesthesia (ACCEPTS): study protocol for a parallel-group randomised comparison trial.

BACKGROUND: The clinical efficacy of effect-site targeted patient-maintained propofol sedation (PMPS) compared to anaesthetist-controlled propofol sedation (ACPS) for patients undergoing awake joint replacement surgery is currently unknown. There is no commercially available medical device capable of delivering PMPS so we have designed and built such a device. We plan a clinical trial to compare PMPS to ACPS and to collect data relating to the safety of our prototype device in delivering sedation. METHODS: The trial is an open-label, randomised, controlled superiority trial recruiting adults who are undergoing elective primary lower-limb arthroplasty with sedation by propofol infusion by effect-site targeting into two equal-sized parallel arms: PMPS and ACPS. The primary research objective is to compare the body-weight-normalised rate of propofol consumption when sedation for surgery on adults undergoing elective primary lower-limb arthroplasty under spinal anaesthesia is patient-maintained versus when it is anaesthetist-controlled. The study primary null hypothesis is that there is no difference in the rate of propofol consumption when sedation is patient-maintained versus anaesthetist-controlled. DISCUSSION: This is the first trial to test the superiority of effect-site-targeted patient-maintained propofol sedation versus anaesthetist-controlled propofol sedation in terms of total propofol consumption during the sedation period. The results of this trial will help inform clinicians and device manufacturers of the clinical efficacy and safety of patient-maintained propofol sedation applied to a common operative setting. TRIAL REGISTRATION: International Standard Randomised Controlled Trial Number Registry, ISRCTN29129799 . Prospectively registered on 12 June 2018.

Regional entropy of functional imaging signals varies differently in sensory and cognitive systems during propofol-modulated loss and return of behavioral responsiveness.

The level and richness of consciousness depend on information integration in the brain. Altered interregional functional interactions may indicate disrupted information integration during anesthetic-induced unconsciousness. How anesthetics modulate the amount of information in various brain regions has received less attention. Here, we propose a novel approach to quantify regional information content in the brain by the entropy of the principal components of regional blood oxygen-dependent imaging signals during graded propofol sedation. Fifteen healthy individuals underwent resting-state scans in wakeful baseline, light sedation (conscious), deep sedation (unconscious), and recovery (conscious). Light sedation characterized by lethargic behavioral responses was associated with global reduction of entropy in the brain. Deep sedation with completely suppressed overt responsiveness was associated with further reductions of entropy in sensory (primary and higher sensory plus orbital prefrontal cortices) but not high-order cognitive (dorsal and medial prefrontal, cingulate, parietotemporal cortices and hippocampal areas) systems. Upon recovery of responsiveness, entropy was restored in the sensory but not in high-order cognitive systems. These findings provide novel evidence for a reduction of information content of the brain as a potential systems-level mechanism of reduced consciousness during propofol anesthesia. The differential changes of entropy in the sensory and high-order cognitive systems associated with losing and regaining overt responsiveness are consistent with the notion of "disconnected consciousness", in which a complete sensory-motor disconnection from the environment occurs with preserved internal mentation.

Propofol sedation during gastrointestinal endoscopy arouses euphoria in a large subset of patients.

BACKGROUND: Propofol is recommended for sedation in gastrointestinal endoscopy (GE), but preliminary data suggest addictive potentials. OBJECTIVE: The objective of this article is to evaluate the frequency of predominantly euphoric reaction after GE and patients' subsequent reminiscences. METHODS: Eighty-two patients undergoing elective GE under propofol sedation were enrolled in a prospective observational study. The grade of anxiety, expectation or relief about the examination's result and affective state in terms of cheerfulness, relaxation, activation, sedation and anxiety were surveyed using a numeric rating scale (1 to 10) immediately before (t1), after GE (t2) and seven days (t3) later. Statistics: hierarchical cluster analysis, heat map, χ2 test and paired t test. RESULTS: Mean propofol dosage was 264 ± 120 mg. Two clusters of mood changes emerged (t1 vs. t2). One (n = 46, 56.1%) was characterized by an unease reaction pattern with equal values regarding cheerfulness, relaxation and anxiety, while relaxation decreased; the other cluster showed a euphoric reaction pattern (n = 36, 43.9%) with markedly increased cheerfulness, relaxation and decreased anxiety. These effects intensified at recall (t3). Despite similar endoscopy results, euphoric cluster patients rated these more positively. CONCLUSION: Propofol induces euphoria in nearly half of the patients undergoing elective GE with persisting, even enhanced reminiscence (germanctr.de, trial number DRKS00011202).

Judicial Precedent-Based Clinical Practice Guidelines of Propofol in Sedative Esthetic Surgery.

BACKGROUND: Propofol is has been widely used for sedation in the field of esthetic surgery because of its favorable pharmacokinetic profile. Propofol sedation-induced side effects are rare. However, when present, they can be serious. The number of malpractice claims associated with propofol sedation has increased in recent years. This study aims to show which procedures lead to the most claims in the field of esthetic surgery through a review of Korean precedents. METHODS: Thirteen precedent cases of propofol sedation in the field of esthetic surgery were collected between 2000 and 2016. We analyzed the type of procedure, administration route, anesthesia provider, complications, timing of damaging events, average indemnification, plaintiff's (patients) winning rate, ratio and the reason of limitation of liability and the key factors affecting the judgement in these cases. RESULTS: Most plaintiffs were women, and in most cases (11/13, 73.3%), the times of the damaging events were in maintenance and the anesthesia provider was the surgeon. The most common complication related to propofol sedation was hypoxic brain damage. Among the 13 cases, 12 were won by the plaintiff. The mean claim settlement was 339,455,814 KRW (USD 301,792.15). The key factors affecting the judgement were administration method and staff, monitoring method, preparation of emergency kit, response to emergencies, transfer to a higher-level hospital, detailed medical recording about event and informed consent. CONCLUSION: The number of claims owing to propofol sedation after esthetic surgery is increasing. Close monitoring during the operation, immediate reaction to an event and thorough medical records were main key factors that influenced the judgement. Preoperative explanation about the possibility of complications was important. The findings will help surgeons achieve high patient satisfaction and reduce liability concerns. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Propofol for implantable cardioverter defibrillator implantation in patients with Brugada syndrome.

AIMS: Avoiding propofol in patients with Brugada syndrome has been suggested because of the theoretical risk of provoking ventricular arrhythmias, although propofol may be selected for conscious sedation during electrophysiological procedures in catheterization laboratories. This study aimed to document periprocedural electrocardiographic changes and adverse events in patients with Brugada syndrome undergoing implantable cardioverter defibrillator (ICD) implantation using propofol sedation. METHODS: We reviewed the clinical data of 53 consecutive patients who underwent ICD implantation during 1998-2011. Sedation was achieved by combining propofol with either midazolam or fentanyl, and a bolus propofol dose (0.5-1 mg/kg) was administered to induce deep sedation. Periprocedural events, including arrhythmias, defibrillations, and hyperthermia episodes, were evaluated, and electrocardiogram (ECG) variables were measured. The need for emergency anesthetic support/intubation and incidence of perioperative complications or mortality were analyzed. RESULTS: Procedure time and cumulative propofol dose for each patient was 125.2 (42.8) min and 204.6 (212.7) mg, respectively. During deep sedation, blood pressure, heart rate, and oxygen saturation were significantly decreased (P < 0.001) such that eight (15.1%) patients required manual ventilation and one (1.9%) needed atropine injection. No significant ECG changes were observed. Only two (3.7%) patients showed newly developed ST elevation in the anterior precordial lead, whereas three (5.6%) had isolated premature ventricular contractions. CONCLUSION: ICD implantation without significant ECG changes or adverse outcomes is feasible under propofol sedation in patients with Brugada syndrome. However, because of significant hemodynamic changes and respiratory compromise, close monitoring and meticulous propofol dose titration is warranted.

No increased risk of perforation during colonoscopy in patients undergoing propofol versus traditional sedation: A meta-analysis.

BACKGROUND AND AIMS: The safety of propofol sedation during colonoscopy remains unclear, and we performed a meta-analysis to assess the risk of perforation in patients undergoing propofol vs. traditional sedation. METHODS: MEDLINE, CBM, VIP, CNKI, and Wanfang databases were searched up to December 2016. Two reviewers independently assessed abstract of those searched articles. Data about perforation condition in propofol and traditional sedation groups were extracted and combined using the random effects model. RESULTS: A total of 19 studies were included in the current meta-analysis. Compared to traditional sedation, propofol sedation did not increase the risk of perforation (RD = - 0.00, 95% CI - 0.00~0.00, p = 0.98; subgroup analysis: OR = 1.30, 95% CI 0.83~2.05, p = 0.25). CONCLUSION: This meta-analysis suggested that propofol sedation did not increase the risk of perforation compared to traditional sedation during colonoscopy.