Bispectral index monitoring of conscious sedation with the combination of meperidine and midazolam during endoscopy

γ-Aminobutyric acid type A receptor β1 subunit gene polymorphisms are associated with the sedative and amnesic effects of midazolam

Midazolam is widely used for intravenous sedation. However, wide interindividual variability is seen in the sensitivity to midazolam. The association between genetic factors and interindividual differences in midazolam sensitivity remains unclear. The present study explored the association between common genetic variants and sedative and amnesic effects of midazolam. This prospective study included patients who were scheduled to undergo dental procedures under intravenous sedation. The sedative effect was evaluated using the Ramsay sedation scale 5 min after midazolam (0.05 mg/kg) administration. We employed two parallel approaches in this study: genome-wide approach and candidate gene approach. The γ-aminobutyric acid type A receptor subunit genes were selected as candidate genes. Multivariate linear regression analyses were performed to investigate the association between the Ramsay sedation scale and genetic variants. We also analyzed the association between the presence of anterograde amnesia and genetic variants using multivariate binominal logistic regression analyses. The analyses were adjusted for potential confounding factors. A total of 191 patients were included in the analyses. In the genome-wide association analyses, no significant association was found between the genetic variants and Ramsay scores. In the candidate gene analyses, the rs73247636 (dominant model: β = 0.72 [95% confidence interval, 0.34 to 1.10], P < 0.001) and rs56278524 (dominant model: β = 0.73 [0.37 to 1.10], P < 0.001) polymorphisms of the GABRB1 gene were significantly associated with Ramsay scores. Additionally, the rs73247636 (dominant model: odds ratio [OR] = 8.39 [2.36 to 29.85], P = 0.001) and rs56278524 (dominant model: OR = 15.26 [3.42 to 68.07], P < 0.001) polymorphisms were also significantly associated with the presence of anterograde amnesia. The rs73247636 and rs56278524 single-nucleotide polymorphisms of GABRB1 were associated with the sedative and amnesic effects of midazolam.

Analgesia nociception index is an indicator of laparoscopic trocar insertion-induced transient nociceptive stimuli

Objective

This study aimed to investigate whether analgesia nociception index (ANI) could be an indicator of perioperative pain during laparoscopic trocar insertion.

Methods

A total of 280 participants of anesthesia receiving laparoscopic surgery were enrolled. Anesthesia induction and maintenance were performed using the Marsh model for target propofol and the Minto model for remifentanil. Systolic blood pressure (SBP), heart rate (HR), and ANI were recorded at skin incision, the first-, second, the last-trocar insertion, and 5 min after the last trocar insertion.

Results

ANI was significantly different among the five groups in the last four time points (all P < 0.05). Pearson's correlation showed that ANI was negatively correlated with SBP (r = -0.114, P = 0.077) and HR (r = -0.247, P < 0.001). The area under the curve of ANI was positively correlated with those of SBP (r = 0.493, P < 0.001) and HR (r = -0.420, P < 0.001). Multivariate logistic regression showed that the ANI was an independent factor associated with intraoperative hemodynamic adverse events only at 5 min after the last trocar insertion.

Conclusions

Under general anesthesia, the change in ANI was consistent with changes in the balance between analgesia and nociceptive stimuli. The ANI can reflect the extent of transient pain but had a poor predictive performance for hemodynamic adverse events.

Bispectral index monitoring for sedation in scheduled adult colonoscopy: A randomized controlled trial

BACKGROUND

Patients should be closely monitored during procedures under sedation outside the operating room, but it is unclear which type of monitoring is best. We investigated the efficacy and safety of BIS monitoring vs conventional monitoring for sedation during colonoscopy.

METHODS

We performed a double-blind clinical trial in 180 patients undergoing elective colonoscopy. Patients were randomized to 1) the BIS group or 2) a control group, in which sedation was monitored with a BIS monitor or the Ramsay Sedation Score, respectively. The primary outcome was the rate of sedation-induced adverse events in both groups. Secondary outcomes were the characteristics of patients who developed adverse events, and time during colonoscopy when these events occurred, propofol and remifentanil dosage, and patient satisfaction.

RESULTS

Univariate analysis showed fewer cardiopulmonary complications in the BIS group (41.11% vs 57.78% in controls; p = 0.02). Multivariate analysis found a significantly higher risk of adverse events in older patients (95% CI, 1.013-1.091; p = 0.0087) and in men (95% CI, 1.129-7.668; p = 0.0272). These events were observed at the hepatic flexure. No significant differences between propofol or remifentanil dosage, use of rescue medication, and patient satisfaction were observed between groups.

CONCLUSIONS

Our data suggest that BIS monitoring during sedation in scheduled colonoscopies reduces adverse respiratory events. Although its routine use in sedation does not appear to be warranted, clinicians should take steps to identify patients with a higher risk of complications who might benefit from this type of monitoring.

Safety and efficacy of a low-dose combination of midazolam, alfentanil, and propofol for deep sedation of elderly patients undergoing ERCP

BACKGROUND

Proper sedation of patients, particularly elderly individuals, who are more susceptible to sedation-related complications, is of significant importance in endoscopic retrograde cholangiopancreatography (ERCP). This study aims to assess the safety and efficacy of a low-dose combination of midazolam, alfentanil, and propofol for deep sedation in elderly patients undergoing ERCP, compared to a group of middle-aged patients.

METHODS

The medical records of 610 patients with common bile duct stones who underwent elective ERCP under deep sedation with a three-drug regimen, including midazolam, alfentanil, and propofol at Shandong Provincial Third Hospital from January 2023 to September 2023 were retrospectively reviewed in this study. Patients were categorized into three groups: middle-aged (50-64 years, n = 202), elderly (65-79 years, n = 216), and very elderly (≥ 80 years, n = 192). Intraoperative vital signs and complications were compared among these groups.

RESULTS

The three groups showed no significant difference in terms of intraoperative variation of systolic blood pressure (P = 0.291), diastolic blood pressure (P = 0.737), heart rate (P = 0.107), peripheral oxygen saturation (P = 0.188), bispectral index (P = 0.158), and the occurrence of sedation-related adverse events including hypotension (P = 0.170) and hypoxemia (P = 0.423).

CONCLUSION

The results suggest that a low-dose three-drug regimen consisting of midazolam, alfentanil, and propofol seems safe and effective for deep sedation of elderly and very elderly patients undergoing ERCP procedures. However, further studies are required to verify these findings and clarify the benefits and risks of this method.

Efficacy of capnographic and bispectral index monitoring on trans-oral therapeutic endoscopy: A prospective observational study

BACKGROUND AND AIM

Oral therapeutic and invasive endoscopy requires deep sedation to reduce patient distress due to prolonged examination and procedures. The usefulness of capnography and bispectral index (BIS) monitoring in the early hypoxia detection in oral therapeutic and invasive endoscopy has yet to be evaluated. This study aimed to investigate the clinical impact of capnography and BIS monitoring on hypoxic events during oral therapeutic and invasive endoscopic procedures.

METHODS

This is a prospective observational study. Trans-oral non-intubated therapeutic and/or invasive endoscopic procedures were performed with conventional monitoring (pulse oximetry, pulse, and blood pressure) as well as additional monitoring (BIS and end-tidal CO₂ concentration). Hypoxia is defined as oxygen saturation of <90% that lasts >15 s. The clinical impact of capnography and BIS monitoring on hypoxic events during oral therapeutic and invasive endoscopic procedures were investigated with the risk factors for hypoxia in each patient.

RESULTS

Patients with hypoxia had significantly more apneas detected using capnography than other patients. The multivariate analysis revealed the detected apnea by capnography as an independent risk factor for hypoxia (odds ratio: 3.48[95% confidence interval: 1.24-9.78], P = 0.02). The BIS was not significantly different as a risk factor for hypoxia; however, per-event analysis revealed significantly decreased BIS values over time in 3 min before hypoxic events.

CONCLUSIONS

Apnea detected by capnography was an independent predictor of hypoxia. The BIS value was not associated with hypoxia events; however, it showed a significant downward trend before hypoxia events.

Identifying Recall Under Sedation by a Novel EEG Based Index of Attention—A Pilot Study

Overview

Recall is an accepted consequence of sedation. But due to the very low prevalence of the more devastating awareness under anesthesia (AUA), it might be of value to assess first the efficacy of new markers for AUA by their efficacy in discovering the more prevalent recall under sedation (RUS). In this pilot study we assessed whether a novel index for attentional effort, the cognitive effort index (CEI), derived in real-time from one forehead EEG channel, could differentiate between patients with or without RUS.

Methods

EEG was sampled from 2 groups: (1) Patients who underwent deep sedation (n = 25) (using drugs according to the anesthesiologist preference, but generally combining either Midazolam or Propofol together with either Fentanyl or Remifentanil). (2) Patients who underwent general anesthesia (GA, n = 13, a negative control for recall). In recovery, recall was assessed using the BRICE questionnaire.

Results

Of the 25 sedated patients, 11 experienced recall. The CEI marker was high during significantly longer periods in patients with recall, compared to sedated patients, or patients under GA, without recall. Moreover, the increase in CEI was evident mainly toward the end of the procedure.

Conclusion

RUS seems to associate with higher level of attention, which is identified in real-time by the easy-to-extract CEI marker.

Target-controlled propofol infusion with or without bispectral index monitoring of sedation during advanced gastrointestinal endoscopy

BACKGROUND AND AIM

Target-controlled infusion (TCI) uses averaged pharmacokinetic datasets derived from population samples to automatically control the infusion rate. Bispectral index (BIS) technology non-invasively measures levels of consciousness during surgical procedures. We compared the efficacy and safety of propofol TCI with or without BIS monitoring for sedation during advanced gastrointestinal endoscopy.

METHODS

This prospective study enrolled 200 patients who were premedicated with midazolam 2 mg and alfentanil 0.4 mg before undergoing advanced gastrointestinal endoscopy. The initial target blood concentration of propofol was set at 1.0 μg/mL, and adjustments of 0.2 μg/mL were made as necessary to maintain moderate-to-deep sedation. Patients were randomized to either the BIS-blind group and evaluated for depth of anesthesia by monitoring scores of 1-2 on the Modified Observer's Assessment of Alertness/Sedation scale (n = 100) or to the BIS-open group and monitored by BIS scores of 60-80 (n = 100). The primary outcome was the total amount of propofol required to maintain anesthesia. Secondary outcomes were sedation-induced adverse events, recovery, and quality of sedation (endoscopist and patient satisfaction).

RESULTS

The mean propofol infusion rate was significantly higher in patients not monitored by BIS scores than in those who were (5.44 ± 2.12 vs 4.76 ± 1.84 mg/kg/h; P = 0.016). Levels of satisfaction were higher for endoscopists who used BIS monitoring than in those who did not.

CONCLUSIONS

Mean infusion rates were higher in propofol TCI without BIS monitoring compared with propofol TCI with BIS during advanced gastrointestinal endoscopy. Endoscopists expressed satisfaction with BIS monitoring.

Evaluation of bispectral index monitoring efficacy in endoscopic patients who underwent retrograde cholangiopancreatography and received sedoanalgesia

INTRODUCTION

Bispectral index (BIS) monitoring provides an objective, non-invasive measurement of the level of consciousness in a sedated patient.

AIM

In this prospective study, we aimed to investigate the hypothesis that risk of respiratory depression could be reduced and the desired level of sedation with minimal doses of propofol could be achieved by using BIS monitoring in endoscopic retrograde cholangiopancreatography (ERCP) procedures.

MATERIAL AND METHODS

Sixty patients in the ASA 1-2 category, who were scheduled for an ERCP with sedation, were randomly divided into two groups. The procedure was performed, and sedation was administered so that the patient's Ramsay Sedation Score (RSS) would be 4-5 in the first group (group 1) and the patient's BIS value would be 65-75 in the second group (group 2). Cardiopulmonary complications, the total duration of the procedure, and the total amount of propofol administered were recorded.

RESULTS

The mean SpO2 measurements at the third minute, fifth minute, and 10th minute were higher in the BIS group (p < 0.001) (p < 0.05). The mean number of respirations during the third, fifth, 10th, and 15th minute of sedation was significantly higher in the RSS group than in the BIS group (p < 0.05). There was no difference between the groups in terms of recovery time, total propofol amount, and additional doses of bolus propofol.

CONCLUSIONS

BIS monitoring during sedation with propofol for ERCP did not reduce total propofol use, but it may be an efficient guide for the timing of additional dose administration, which could reduce the risk of respiratory depression, and it could be used safely as an objective method in the follow-up of level of sedation.

SEDATION IN COLONOSCOPY BY USING THREE DIFFERENT PROPOFOL INFUSION METHODS AND ANALYSIS OF PLASMA CONCENTRATION LEVELS: A PROSPECTIVE COMPARATIVE STUDY

Background

The propofolemia becomes directly linked to the clinical effects of this anesthetic and is the focus for studies comparing propofol clinical use, in different administration methods routinely used in endoscopy units where sedation is widely administered to patients.

Aim

To evaluate the effects of three different regimens of intravenous propofol infusion in colonoscopies.

Methods

A total of 50 patients that underwent colonoscopies were consecutively assigned to three groups: 1) intermittent bolus infusion; 2) continuous manually controlled infusion; 3) continuous automatic infusion. Patients were monitored with Bispectral IndexTM (BIS) and propofol serum levels were collected at three different timepoints. The development of an original dilution of propofol and an inventive capnography catheter were necessary.

Results

Regarding clinical outcomes, statistical differences in agitation (higher in group 1, p=0.001) and initial blood pressure (p=0.008) were found. As for propofol serum levels, findings were similar in consumption per minute (p=0.748) and over time (p=0.830). In terms of cost analysis, group 1 cost was R$7.00 (approximately US$2,25); group2, R$17.50 (approximately US$5,64); and group 3, R$112.70 (approximately US$36,35, p<0.001). Capnography was able to predict 100% of the oxygen saturation drop (below 90%).

Conclusion

The use of propofol bolus administration for colonoscopies, through continuous manually controlled infusion or automatic infusion are similar regarding propofolemia and the clinical outcomes evaluated. The use of an innovative capnography catheter is liable and low-cost solution for the early detection of airway obstruction.

Extended Monitoring during Endoscopy

Gastrointestinal endoscopic sedation has improved procedural and patient outcomes but is associated with attendant risks of oversedation and hemodynamic compromise. Therefore, close monitoring during endoscopic procedures using sedation is critical. This monitoring begins with appropriate staff trained in visual assessment of patients and analysis of basic physiologic parameters. It also mandates an array of devices widely used in practice to evaluate hemodynamics, oxygenation, ventilation, and depth of sedation. The authors review the evidence behind monitoring practices and current society recommendations and discuss forthcoming technologies and techniques that are poised to improve noninvasive monitoring of patients under endoscopic sedation.

Sedation in the Endoscopy Suite

OPINION STATEMENT

Sedation practices in the endoscopy suite have changed dramatically in the decades since the introduction of routine colonoscopy and esophagogastroduodenoscopy (EGD). Patients initially received moderate sedation (or even no sedation), but now frequently receive monitored anesthesia care (MAC). This significant shift has introduced anesthesiologists to the endoscopy suite along with new sedative medications and safety concerns. Appreciating the ramifications of this change requires an understanding of sedation depth, patient selection, drug use, sedation delivery, patient monitoring, recovery from sedation, and patient outcomes. Furthermore, the changing landscape of healthcare quality and reimbursement challenges us to provide the best possible care for our patients in the most economical way possible. The endoscopy suite is a unique sedation environment, and it is the purpose of this article to review those elements that contribute to a uniquely demanding work environment.

Determination of the appropriate propofol infusion rate for outpatient upper gastrointestinal endoscopy-a randomized prospective study

Background

Pain and discomfort related to endoscopy sessions can be alleviated by sedation, which minimizes anxiety and allows safe examination. For outpatient endoscopy, reliable short-term sedation without secondary effects is required. This study aimed to assess the effects of intravenous propofol rates on sedation in outpatients undergoing upper gastrointestinal endoscopy.

Methods

This randomized prospective study evaluated 300 outpatients submitted to upper gastrointestinal endoscopy. Patients received propofol at 500, 1000 or 2000 ml/h. The primary outcome assessed was hypoxemia incidence. In addition, time to sedation and incidence of hypotension, deep sedation, extremity motor activity, cough, nausea, hiccough, and awareness were evaluated.

Results

Recovery time and incidence of hypoxemia, hypotension, and deep sedation were significantly increased in individuals treated at 2000 ml/h in comparison with values obtained for 500 and 1000 ml/h groups (P < 0.01). Compared with the 500 ml/h group, motor activity of the extremities, cough, nausea, hiccough, and awareness were significantly decreased and the mean scores for endoscopist’s and patients’ satisfaction were significantly increased in the 1000 and 2000 ml/h groups (P < 0.01).

Conclusion

Propofol infused at 1000 ml/h appeared to be the most suitable infusion rate for outpatient upper gastrointestinal endoscopy.

Trial registration

Registration number: ChiCTR-TRC-14004786; Registration date: 2014-06-04

Efficacy Outcome Measures for Procedural Sedation Clinical Trials in Adults: An ACTTION Systematic Review

Successful procedural sedation represents a spectrum of patient- and clinician-related goals. The absence of a gold-standard measure of the efficacy of procedural sedation has led to a variety of outcomes being used in clinical trials, with the consequent lack of consistency among measures, making comparisons among trials and meta-analyses challenging. We evaluated which existing measures have undergone psychometric analysis in a procedural sedation setting and whether the validity of any of these measures support their use across the range of procedures for which sedation is indicated. Numerous measures were found to have been used in clinical research on procedural sedation across a wide range of procedures. However, reliability and validity have been evaluated for only a limited number of sedation scales, observer-rated pain/discomfort scales, and satisfaction measures in only a few categories of procedures. Typically, studies only examined 1 or 2 aspects of scale validity. The results are likely unique to the specific clinical settings they were tested in. Certain scales, for example, those requiring motor stimulation, are unsuitable to evaluate sedation for procedures where movement is prohibited (e.g., magnetic resonance imaging scans). Further work is required to evaluate existing measures for procedures for which they were not developed. Depending on the outcomes of these efforts, it might ultimately be necessary to consider measures of sedation efficacy to be procedure specific.

Effects of bispectral index monitoring as an adjunct to nurse-administered propofol combined sedation during colonoscopy: a randomized clinical trial

BACKGROUND/AIMS

The efficacy of bispectral index (BIS) monitoring during colonoscopic sedation is debated. We aimed to determine whether BIS monitoring was useful for propofol dose titration, and to evaluate differences in sedative administration between expert and inexperienced medical personnel during colonoscopy procedures that required moderate sedation.

METHODS

Between February 2012 and August 2013, 280 consecutive patients scheduled to undergo a screening colonoscopy participated in this study and were randomly allocated to the expert or inexperienced endoscopist group. Each group was further divided into either a BIS or a modified Observer's Assessment of Alertness/Sedation Scale (MOAA/S) subgroup. Trained nurses administered combined propofol sedation and monitored sedation using either the BIS or MOAA/S scale.

RESULTS

The mean BIS value throughout the procedure was 74.3 ± 6.7 for all 141 patients in the BIS group. The mean total propofol dose administered in the BIS group was higher than that in the MOAA/S group, independently of the endoscopists' experience level (36.9 ± 29.6 and 11.3 ± 20.7, respectively; p < 0.001). The total dose of propofol administered was not significantly different between the inexperienced endoscopist group and the expert endoscopist group, both with and without the use of BIS (p = 0.430 and p = 0.640, respectively).

CONCLUSIONS

Compared with monitoring using the MOAA/S score alone, BIS monitoring was not effective for titrating the dose of propofol during colonoscopy, irrespective of colonoscopist experience.

A randomized controlled trial of light versus deep propofol sedation for elective outpatient colonoscopy: recall, procedural conditions, and recovery

PURPOSE

This study aimed to determine if the incidence of recall was equivalent between light and deep sedation for colonoscopy. Secondary analysis included complications, patient clinical recovery, and post-procedure cognitive impairment.

METHODS

Two hundred patients undergoing elective outpatient colonoscopy were randomized to light (bispectral index [BIS] 70-80) or deep (BIS < 60) sedation with propofol and fentanyl. Recall was assessed by the modified Brice questionnaire, and cognition at baseline and discharge was assessed using a Cogstate test battery.

RESULTS

The median (interquartile range [IQR]) BIS values were different in the two groups (69 [65-74] light sedation vs 53 [46-59] deep sedation; P < 0.0001). The incidence of recall was 12% in the light sedation group and 1% in the deep sedation group. The risk difference for recall was 0.11 (90% confidence interval, 0.05 to 0.17) in the intention-to-treat analysis, thus refuting equivalence in recall between light and deep sedation (0.05 significance level; 10% equivalence margin). Overall sedation-related complications were more frequent with deep sedation than with light sedation (66% vs 47%, respectively; P = 0.008). Recovery was more rapid with light sedation than with deep sedation as determined by the mean (SD) time to reach a score of 5 on the Modified Observer's Assessment of Alertness/Sedation Scale [3 (4) min vs 7 (4) min, respectively; P < 0.001] and by the median [IQR] time to readiness for hospital discharge (65 [57-80] min vs 74 [63-86] min, respectively; P = 0.001). The incidence of post-procedural cognitive impairment was similar in those randomized to light (19%) vs deep (16%) sedation (P = 0.554).

CONCLUSION

Light sedation was not equivalent to deep sedation for procedural recall, the spectrum of complications, or recovery times. This study provides evidence to inform discussions with patients about sedation for colonoscopy. This trial was registered at the Australian and New Zealand Clinical Trials Registry, number 12611000320954.

Deep sedation during gastrointestinal endoscopy: propofol-fentanyl and midazolam-fentanyl regimens

AIM

To compare deep sedation with propofol-fentanyl and midazolam-fentanyl regimens during upper gastrointestinal endoscopy.

METHODS

After obtaining approval of the research ethics committee and informed consent, 200 patients were evaluated and referred for upper gastrointestinal endoscopy. Patients were randomized to receive propofol-fentanyl or midazolam-fentanyl (n = 100/group). We assessed the level of sedation using the observer's assessment of alertness/sedation (OAA/S) score and bispectral index (BIS). We evaluated patient and physician satisfaction, as well as the recovery time and complication rates. The statistical analysis was performed using SPSS statistical software and included the Mann-Whitney test, χ² test, measurement of analysis of variance, and the κ statistic.

RESULTS

The times to induction of sedation, recovery, and discharge were shorter in the propofol-fentanyl group than the midazolam-fentanyl group. According to the OAA/S score, deep sedation events occurred in 25% of the propofol-fentanyl group and 11% of the midazolam-fentanyl group (P = 0.014). Additionally, deep sedation events occurred in 19% of the propofol-fentanyl group and 7% of the midazolam-fentanyl group according to the BIS scale (P = 0.039). There was good concordance between the OAA/S score and BIS for both groups (κ = 0.71 and κ = 0.63, respectively). Oxygen supplementation was required in 42% of the propofol-fentanyl group and 26% of the midazolam-fentanyl group (P = 0.025). The mean time to recovery was 28.82 and 44.13 min in the propofol-fentanyl and midazolam-fentanyl groups, respectively (P < 0.001). There were no severe complications in either group. Although patients were equally satisfied with both drug combinations, physicians were more satisfied with the propofol-fentanyl combination.

CONCLUSION

Deep sedation occurred with propofol-fentanyl and midazolam-fentanyl, but was more frequent in the former. Recovery was faster in the propofol-fentanyl group.

Sedation and monitoring for gastrointestinal endoscopy

The safe sedation of patients for diagnostic or therapeutic procedures requires a combination of properly trained physicians and suitable facilities. Additionally, appropriate selection and preparation of patients, suitable sedative technique, application of drugs, adequate monitoring, and proper recovery of patients is essential. The goal of procedural sedation is the safe and effective control of pain and anxiety as well as to provide an appropriate degree of memory loss or decreased awareness. Sedation practices for gastrointestinal endoscopy (GIE) vary widely. The majority of GIE patients are ambulatory cases. Most of this procedure requires a short time. So, short acting, rapid onset drugs with little adverse effects and improved safety profiles are commonly used. The present review focuses on commonly used regimens and monitoring practices in GIE sedation. This article is to discuss the decision making process used to determine appropriate pre-sedation assessment, monitoring, drug selection, dose of sedative agents, sedation endpoint and post-sedation care. It also reviews the current status of sedation and monitoring for GIE procedures in Thailand.

Bispectral index monitoring as an adjunct to nurse-administered combined sedation during endoscopic retrograde cholangiopancreatography

AIM: To determine whether bispectral index (BIS) monitoring is useful for propofol administration for deep sedation during endoscopic retrograde cholangiopancreatography (ERCP).

METHODS: Fifty-nine consecutive patients with a variety of reasons for ERCP who underwent the procedure at least twice between 1 July 2010 and 30 November 2010. This was a randomized cross-over study, in which each patient underwent ERCP twice, once with BIS monitoring and once with control monitoring. Whether BIS monitoring was done during the first or second ERCP procedure was random. Patients were intermittently administered a mixed regimen including midazolam, pethidine, and propofol by trained nurses. The nurse used a routine practice to monitor sedation using the Modified Observer’s Assessment of Alertness/Sedation (MOAA/S) scale or the BIS monitoring. The total amount of midazolam and propofol used and serious side effects were compared between the BIS and control groups.

RESULTS: The mean total propofol dose administered was 53.1 ± 32.2 mg in the BIS group and 54.9 ± 30.8 mg in the control group (P = 0.673). The individual propofol dose received per minute during the ERCP procedure was 2.90 ± 1.83 mg/min in the BIS group and 3.44 ± 2.04 mg in the control group (P = 0.103). The median value of the MOAA/S score during the maintenance phase of sedation was comparable for the two groups. The mean BIS values throughout the procedure (from insertion to removal of the endoscope) were 76.5 ± 8.7 for all 59 patients in using the BIS monitor. No significant differences in the frequency of < 80% oxygen saturation, hypotension (< 80 mmHg), or bradycardia (< 50 beats/min) were observed between the two study groups. Four cases of poor cooperation occurred, in which the procedure should be stopped to add the propofol dose. After adding the propofol, the procedure could be conducted successfully (one case in the BIS group, three cases in the control group). The endoscopist rated patient sedation as excellent for all patients in both groups. All patients in both groups rated their level of satisfaction as high (no discomfort). During the post-procedural follow-up in the recovery area, no cases of clinically significant hypoxic episodes were recorded in either group. No other postoperative side effects related to sedation were observed in either group.

CONCLUSION: BIS monitoring trend to slighlty reduce the mean propofol dose. Nurse-administered propofol sedation under the supervision of a gastroenterologist may be considered an alternative under anesthesiologist.

Efficacy of Bispectral Index Monitoring for Midazolam and Meperidine Induced Sedation during Endoscopic Submucosal Dissection: A Prospective, Randomized Controlled Study

BACKGROUND/AIMS

Propofol induced sedation with bispectral index (BIS) monitoring has been reported to lead to higher satisfaction in patients and endoscopists during endoscopic submucosal dissection (ESD) procedures. There are no data, however, regarding the efficacy of midazolam and meperidine (M/M) induced sedation with BIS monitoring during ESD. The purpose of this study was to evaluate whether M/M induced sedation with BIS monitoring could improve satisfaction and reduce the dose of M/M required during ESD.

METHODS

Between September 2009 and January 2010, 56 patients were prospectively enrolled and randomly assigned to a BIS group (n=28) and a non-BIS group (n=28). Patient and endoscopist satisfaction scores were assessed using the visual analog scale (0 to 100) following the ESD.

RESULTS

The mean satisfaction scores did not significantly differ between the BIS and non-BIS groups (92.3±16.3 vs 93.3±15.5, p=0.53) or endoscopists (83.1±15.4 vs 80.0±16.7, p=0.52). Although the mean meperidine dose did not differ (62.5±27.6 vs 51.0±17.3, p=0.18) between the two groups, the mean dose of midazolam in the non-BIS group was lower than in the BIS group (6.8±2.0 vs 5.4±2.1, p=0.01).

CONCLUSIONS

BIS monitoring during ESD did not increase the satisfaction of endoscopists or patients and did not lead to an M/M dose reduction. These results demonstrate that BIS monitoring provides no additional benefit to M/M induced sedation during ESD.

General anesthesia occurs frequently in elderly patients during propofol-based sedation and spinal anesthesia

STUDY OBJECTIVE

To test the hypothesis that sedation in elderly patients is often electrophysiologically equivalent to general anesthesia (GA).

DESIGN

Prospective, observational study.

SETTING

Operating room of a university medical center.

PATIENTS

40 elderly patients (>or=65 yrs of age) undergoing hip fracture repair with spinal anesthesia and propofol-based sedation.

INTERVENTIONS

In the routine practice group (RP; n = 15), propofol sedation was administered per the usual routine of the anesthesiologist. In the targeted sedation group (TS; n = 25), sedation was titrated to an observer's assessment of alertness/sedation (OAA/S) score of 4 (ie, lethargic in response to name called) to 5 (ie, awake and alert).

MEASUREMENTS

Both patient groups underwent processed electroencephalographic monitoring using bispectral index (BIS) intraoperatively. BIS levels were compared between groups to determine amount of surgical time spent in GA (BIS <or= 60).

MAIN RESULTS

In the RP group, subjects spent 32.2% of surgical time at BIS levels consistent with GA. Although averaged BIS values during surgery increased from (mean +/- SD) 71 +/- 16 to 88 +/- 9 (P < 0.001), GA was still observed during 5% of surgical time in the TS group. Overall, 13 of 15 (87%) RP group patients and 11 of 25 (44%) TS group patients (P < 0.010) experienced some period of GA.

CONCLUSIONS

BIS levels consistent with GA occur frequently in elderly patients during propofol-based sedation for spinal anesthesia. Altering routine practice such that sedation is titrated to a targeted clinically-determined sedation level reduces - but does not eliminate - this incidence.

Sedation during upper GI endoscopy in cirrhotic outpatients: a randomized, controlled trial comparing propofol and fentanyl with midazolam and fentanyl

BACKGROUND

Patients with liver cirrhosis frequently undergo diagnostic or therapeutic upper GI endoscopy (UGIE), and the liver disease might impair the metabolism of drugs usually administered for sedation.

OBJECTIVE AND SETTING

To compare sedation with a combination of propofol plus fentanyl and midazolam plus fentanyl in cirrhotic outpatients undergoing UGIE.

DESIGN

A prospective, randomized, controlled trial was conducted between February 2008 and February 2009.

MAIN OUTCOMES MEASUREMENTS

Efficacy (proportion of complete procedures using the initial proposed sedation scheme), safety (occurrence of sedation-related complications), and recovery time were measured.

RESULTS

Two hundred ten cirrhotic patients referred for UGIE were randomized to 2 groups: midazolam group (0.05 mg/kg plus fentanyl 50 μg intravenously) or propofol group (0.25 mg/kg plus fentanyl 50 μg intravenously). There were no differences between groups regarding age, sex, weight, etiology of cirrhosis, and Child-Pugh or American Society of Anesthesiologists classification. Sedation with propofol was more efficacious (100% vs 88.2%; P < .001) and had a shorter recovery time than sedation with midazolam (16.23 ± 6.84 minutes and 27.40 ± 17.19 minutes, respectively; P < .001). Complication rates were similar in both groups (14% vs 7.3%; P = .172).

LIMITATIONS

Single-blind study; sample size.

CONCLUSION

Both sedation schemes were safe in this setting. Sedation with propofol plus fentanyl was more efficacious with a shorter recovery time compared with midazolam plus fentanyl. Therefore, the former scheme is an alternative when sedating cirrhotic patients undergoing UGIE.

Optimal sedation for gastrointestinal endoscopy: review and recommendations

Sedation practices for endoscopy vary widely. The present review focuses on the commonly used regimens in endoscopic sedation and the associated risks and benefits together with the appropriate safety measures and monitoring practices. In addition, alternatives and additions to intravenous sedation are discussed. Personnel requirements for endoscopic sedation are reviewed; there is evidence presented to indicate that non-anesthetists can administer sedative drugs, including propofol, safely and efficaciously in selected cases. The development of endoscopic sedation as a multi-disciplinary field is highlighted with the formation of the Australian Tripartite Endoscopy Sedation Committee. This comprises representatives of the Australian and New Zealand College of Anaesthetists, the Gastroenterological Society of Australia and the Royal Australasian College of Surgeons. Possible future directions in this area are also briefly summarized.

Incidence of sedation-related complications with propofol use during advanced endoscopic procedures

BACKGROUND & AIMS

Propofol is an effective sedative in advanced endoscopy. However, the incidence of sedation-related complications is unclear. We sought to define the frequency of sedation-related adverse events, particularly the rate of airway modifications (AMs), with propofol use during advanced endoscopy. We also evaluated independent predictors of AMs.

METHODS

Patients undergoing sedation with propofol for advanced endoscopic procedures, including endoscopic retrograde cholangiopancreatography, endoscopic ultrasound, and small-bowel enteroscopy, were studied prospectively. Sedative dosing was determined by a certified registered nurse anesthetist with the goal of achieving deep sedation. Sedation-related complications included AMs, hypoxemia (pulse oximetry [SpO(2)] < 90%), hypotension requiring vasopressors, and early procedure termination. AMs were defined as chin lift, modified face mask ventilation, and nasal airway. We performed a regression analysis to compare characteristics of patients requiring AMs (AM+) with those who did not (AM-).

RESULTS

A total of 799 patients were enrolled over 7 months. Procedures included endoscopic ultrasound (423), endoscopic retrograde cholangiopancreatography (336), and small-bowel enteroscopy (40). A total of 87.2% of patients showed no response to endoscopic intubation. Hypoxemia occurred in 12.8%, hypotension in 0.5%, and premature termination in 0.6% of the patients. No patients required bag-mask ventilation or endotracheal intubation. There were 154 AMs performed in 115 (14.4%) patients, including chin lift (12.1%), modified face mask ventilation (3.6%), and nasal airway (3.5%). Body mass index, male sex, and American Society of Anesthesiologists class of 3 or higher were independent predictors of AMs.

CONCLUSIONS

Propofol can be used safely for advanced endoscopic procedures when administered by a trained professional. Independent predictors of AMs included male sex, American Society of Anesthesiologists class of 3 or higher, and increased body mass index.

Procedural sedation and obesity: waters left uncharted

BACKGROUND

Moderate sedation during endoscopy may pose increased risks among obese patients.

OBJECTIVE

To review the literature that considers aspects of sedation within the obese population and to identify gaps in our knowledge.

DESIGN

Literature-based review.

RESULTS

There may be increased risks among obese patients undergoing moderate sedation. In particular, the presence of obstructive sleep apnea may identify a subset of patients at higher risk for complications.

LIMITATIONS

English language literature only.

CONCLUSIONS

Although obesity may be associated with increased risks of procedural sedation, future studies should better clarify such risks to better inform clinical decision making.

Risk factors for hypoxemia during ambulatory gastrointestinal endoscopy in ASA I-II patients

BACKGROUND

Most studies identify the American Society of Anesthesiology (ASA) classification as the most significant risk factor for hypoxemia. The risk factors operative within ASA I and II patients are not well defined. Therefore, we analyzed prospectively collected data to identify the risk factors of hypoxemia in such patients.

METHODS

A combination of a narcotic and benzodiazepine was used for sedation and oxygen was supplemented if hypoxemia (oxygen saturation <or=90%) developed. Univariate and multivariate analyses were performed and correlations estimated for predetermined clinical variables.

RESULTS

40 of 79 patients (51%) developed hypoxemia, which occurred more frequently in the obese (71%; 10/14) than the nonobese (46%; 30/65) group (P=0.08). On multivariate analysis, the odds ratios (OR) and 95% confidence intervals (CI) for developing hypoxemia were age >or= 60 years 4.5 (1.4-14.3) P=0.01, and incremental 25-mg doses of meperidine 2.6 (1.02-6.6) P = 0.04. Body mass index (BMI) significantly correlated with the number of hypoxemic episodes (rho 0.26, 95% CI 0.04-0.48, P=0.02).

CONCLUSION

In ASA I and II patients, BMI significantly correlated with the number of hypoxemic episodes, whereas age >or= 60 years and meperidine dose were significant risk factors for hypoxemia.

Capnographic monitoring of respiratory activity improves safety of sedation for endoscopic cholangiopancreatography and ultrasonography

BACKGROUND & AIMS

The Joint Commission on the Accreditation of Healthcare Organizations recommends ventilation monitoring during procedural sedation for gastrointestinal endoscopy. We sought to determine whether intervention, based on a microstream capnography-based ventilation monitoring system that has been shown to function as an early warning system for hypoxemia, would decrease hypoxemia during endoscopy.

METHODS

Subjects undergoing elective endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasonography (EUS) under procedural sedation with a combination of opioid and benzodiazepine were randomly assigned to either a study arm in which the endoscopy team was blinded to capnography or an open arm in which the endoscopy team was prompted of capnographic changes. The primary end point was the occurrence of hypoxemia; secondary end points were the occurrences of severe hypoxemia, apnea, and oxygen supplementation.

RESULTS

A total of 263 subjects were enrolled; 247 were analyzed for efficacy. The numbers of hypoxemic events in the blinded and open arms were 132 and 69, respectively (P < .001). Thirty-five percent of all hypoxemic events occurred with completely normal ventilation. Hypoxemia developed in 69% of patients in the blinded arm compared with 46% in the open arm (P < .001). Severe hypoxemia percentages in the blinded and open arms were 31% and 15% (P = .004), for apnea were 63% and 41% (P < .001), for oxygen supplementation were 67% and 52% (P = .02), and for recurrent hypoxemia after oxygen supplementation were 38% and 18% (P = .01), respectively.

CONCLUSIONS

Capnographic monitoring of respiratory activity improves patient safety during procedural sedation for elective ERCP/EUS by reducing the frequency of hypoxemia, severe hypoxemia, and apnea.

Auditory evoked potentials compared with bispectral index for monitoring of midazolam and propofol sedation during colonoscopy

OBJECTIVES

The purpose of this study was to evaluate and compare Bispectral index (BIS) and A-line auditory evoked potential index (AAI) for monitoring depth of low-dose midazolam and propofol sedation during colonoscopy.

METHODS

A total of 115 consecutive patients (ASA I-IV), receiving low-dose midazolam and propofol sedation for colonoscopy, were evaluated. BIS and AAI levels, Observer's Assessment of Alertness/Sedation (OAA/S) scores, blood pressure, heart rate, oxygen saturation, as well as the presence or absence of eyelash reflex, patient reaction to an external noxious stimulus and to procedure-related pain were recorded every 1-3 min by a single trained observer.

RESULTS

There was a positive correlation between BIS and OAA/S scores (correlation coefficient=0.77) and to a lesser extent AAI and OAA/S scores (correlation coefficient=0.47). BIS and AAI showed significant differences between subsequent levels of sedation (P<0.001). The clustered receiver operating characteristic curve estimate of BIS for the detection of deep sedation was significantly better than that of AAI (P<0.001). Regarding the presence or absence of eyelash reflex and patient reaction to an external noxious stimulus and to procedure-related pain, significant different levels were found for BIS as well as AAI, respectively. Only small changes were observed in hemodynamic variables and oxygen saturation. Overall, our data suggest target BIS levels of slightly above 73 for moderate sedation (defined as OAA/S scores 2 and 3).

CONCLUSIONS

BIS and AAI correlated with the level of sedation. Hemodynamic variables were poor indicators of the hypnotic-anesthetic status of the patient. BIS discriminated best between moderate and deep sedation and could complement clinical observation for guidance of moderate sedation.

A study to assess the value of bispectral analysis in intravenous sedation with midazolam during third molar surgery under local anaesthesia

This study aimed to determine whether bispectral index (BIS) can be used as an indicator of sedation and recovery with intravenous midazolam. In Part A, 30 healthy patients undergoing third molar extraction under local anaesthesia were recruited. They were sedated with intravenous midazolam titrated to clinical endpoints. BIS values were recorded when adequately sedated (BIS(S)) and when clinical recovery criteria were met (BIS). In Part B, another 30 patients were sedated to the range of BIS(S) obtained in Part A. Recovery was assessed postoperatively when the range of BIS(R) from Part A was reached. BIS titrated patients required less midazolam (p < 0.001). Seventy percent of Part B patients required increments of midazolam during surgery, compared to 16.7% in Part A (p < 0.001). Total dose of midazolam given was lower in Part B (p = 0.025). BIS is not effective as a sole indicator of endpoint in sedation with intravenous midazolam.

Patient monitoring during gastrointestinal endoscopy: why, when, and how?

Patient monitoring is intended to reduce the risk of sedation-related cardiopulmonary complications. Physiological monitoring and visual assessment by a qualified individual should be routine during endoscopic procedures. Additionally, ventilatory monitoring should be considered for high-risk patients and those receiving sedation with propofol.