The science and politics of propofol

A Bibliometric Analysis of Endoscopic Sedation Research: 2001-2020

Background and Aims: To evaluate endoscopic sedation research and predict research hot spots both quantitatively and qualitatively using bibliometric analysis. Methods: We extracted relevant publications from the Web of Science Core Collection (WoSCC) on 13 December 2020. We examined the retrieved data by bibliometric analysis (e.g., co-cited and cluster analysis, keyword co-occurrence) using the software CiteSpace and VOSviewer and the website of bibliometrics, the Online Analysis Platform of Literature Metrology (http://bibliometric.com/), to analyse and predict the trends and hot spots in this field. Main Results: We identified 2,879 articles and reviews on endoscopic sedation published between 2001 and 2020. Although the overall trend is increasing, with slight fluctuation in some years, there were significant increases in 2007 and 2012. In respect of the contributions on endoscopic sedation research, the United States (US) had the greatest number of publications, and it was followed by Japan and China. In addition, collaboration network analysis revealed that the most frequent collaboration was between the US and China. Six of the top ten most prolific research institutions were located in the US. The most publications on endoscopic sedation research in the past two decades were found primarily in journals on gastroenterology and hepatology. Keyword co-occurrence and co-citation cluster analysis revealed the most popular terms relating to endoscopic sedation in the manner of cluster labels; these included patient anxiety, tolerance, ketamine, propofol, hypoxia, nursing shortage, endoscopic ultrasonography, colorectal cancer, carbon dioxide insufflation, and water exchange (WE). Keyword burst detection suggested that propofol sedation, adverse event, adenoma detection rate (ADR), hypoxemia, and obesity were newly-emergent research hot spots. Conclusions: Our findings showed that hypoxia, adverse event, and ADR, along with conscious sedation and propofol sedation, have been foci of endoscopic sedation research over the past 20 years. The research focus has shifted from sedative drugs to sedative complications and endoscopy quality control, which means that there will be higher requirements and standards for sedative quality and endoscopy quality in the future.

Sedation During Endoscopy in Patients with Cirrhosis: Safety and Predictors of Adverse Events

BACKGROUND

Sedation during endoscopy in cirrhotic patients is typically via moderate sedation, most commonly using a combination of a benzodiazepine (i.e., midazolam) and narcotic (i.e., fentanyl) or with propofol using monitored anesthesia care (MAC). Here, we examined the safety of moderate sedation and MAC in patients with cirrhosis.

METHODS

This retrospective cohort study of cirrhotic patients undergoing endoscopy from a large academic medical center between 2010 and 2014 examined extensive clinical data including the following: past history, physical findings, laboratory results, and procedural adverse events. Adverse events were defined a priori and included hypoxia, hypotension, bleeding, and death.

RESULTS

We identified 2618 patients with cirrhosis who underwent endoscopic procedures; the mean age was 56 years, 36% were female, the mean Child-Pugh score was 9.3 (IQR: 8, 11), and Charlson Comorbidity Index score was 3.2 (IQR: 1, 4); 1157 had MAC; and 1461 had moderate sedation. There was no difference in the frequency of adverse events in MAC and moderate sedation groups, with a total of 15 adverse events (7/1157 MAC and 8/1461 moderate sedation). The most common procedure performed was esophagogastroduodenoscopy (EGD, n = 1667) and was associated with 10 adverse events. Overall, adverse events included bradycardia (1), hypoxia (7), bleeding (5), laryngospasm (1), and perforation (1). The frequency was similar for EGD, ERCP, and colonoscopy-each at a rate of 0.6%.

CONCLUSIONS

Adverse events in cirrhotic patients undergoing endoscopy appeared to be similar with moderate sedation or MAC, and the frequency was the same for different types of procedures.

Sedation for routine gastrointestinal endoscopic procedures: a review on efficacy, safety, efficiency, cost and satisfaction

Most gastrointestinal endoscopic procedures are now performed with sedation. Moderate sedation using benzodiazepines and opioids continue to be widely used, but propofol sedation is becoming more popular because its unique pharmacokinetic properties make endoscopy almost painless, with a very predictable and rapid recovery process. There is controversy as to whether propofol should be administered only by anesthesia professionals (monitored anesthesia care) or whether properly trained non-anesthesia personnel can use propofol safely via the modalities of nurse-administered propofol sedation, computer-assisted propofol sedation or nurse-administered continuous propofol sedation. The deployment of non-anesthesia administered propofol sedation for low-risk procedures allows for optimal allocation of scarce anesthesia resources, which can be more appropriately used for more complex cases. This can address some of the current shortages in anesthesia provider supply, and can potentially reduce overall health care costs without sacrificing sedation quality. This review will discuss efficacy, safety, efficiency, cost and satisfaction issues with various modes of sedation for non-advanced, non-emergent endoscopic procedures, mainly esophagogastroduodenoscopy and colonoscopy.

Using efficiency analysis and targeted intervention to improve operational performance and achieve cost savings in the endoscopy center

BACKGROUND

With an increasing demand for endoscopy services, there is a greater need for efficiency within the endoscopy center. A validated methodology is important for evaluating efficiency in the endoscopy unit.

OBJECTIVE

To use the principles of operations management to establish a validated methodology for evaluating and enhancing operational performance in the endoscopy center.

DESIGN

Biphasic prospective study with pre-intervention and post-intervention efficiency data and analysis.

SETTING

Tertiary-care referral teaching hospital.

PATIENTS

Scheduled outpatients undergoing endoscopy.

INTERVENTION

Determination of the rate-limiting step, or bottleneck, of the endoscopy unit and reducing inefficiencies.

MAIN OUTCOME MEASUREMENTS

Staffing costs and a novel performance metric, True Completion Time (TCT).

RESULTS

Data were prospectively recorded for 2248 patients undergoing a total of 2713 procedures (phase I: 255 EGD, 305 colonoscopy, 91 EGD/colonoscopy, 375 EUS, 44 ERCP, 75 EUS/ERCP; phase II: 243 EGD, 328 colonoscopy, 99 EGD/colonoscopy, 335 EUS, 38 ERCP, 109 EUS/ERCP). The bottleneck of the operation was identified as the 10-bed communal pre-procedure/recovery room. On-time procedure starts increased by 51% (P < .001), and TCT was reduced by 12.2% (P < .001) across all cases studied. Overtime and per diem nursing costs were reduced by 30%, whereas full-time employee staff was reduced by 0.85. Annual cost savings were calculated as $312,618 or 11.02% of total operating expenses.

LIMITATIONS

This study is not directly tied to quality outcomes, and inpatient procedures transported to the endoscopy unit were not directly studied.

CONCLUSION

Room turnover time and room-to-endoscopist ratio are not necessarily the driving parameters behind endoscopy unit efficiency. A focus on developing a methodology for identifying factors constraining operational efficiency can improve performance and reduce costs in the endoscopy center.

Regional variation in anesthesia assistance during outpatient colonoscopy is not associated with differences in polyp detection or complication rates

BACKGROUND & AIMS

We investigated the rate and predictors of anesthesia assistance during outpatient colonoscopy and whether anesthesia assistance is associated with colonoscopy interventions and outcomes.

METHODS

We performed a retrospective cohort study using a 20% sample of Medicare administrative claims submitted during the 2003 calendar year. We analyzed data from 328,177 adults, 66 years old or older, who underwent outpatient colonoscopy examinations.

RESULTS

Overall, 8.7% of outpatient colonoscopies were performed with anesthesia assistance. In multivariate analysis, independent predictors of anesthesia assistance included black race, female sex, and a nonscreening indication; anesthesia assistance increased with median income and comorbidities. General and colorectal surgeons, fewer years in their practice, and nonhospital site of service were also significantly associated with anesthesia assistance. The strongest predictor of anesthesia assistance was the Medicare carrier, with odds ratios ranging from 0.22 (95% confidence interval: 0.12-0.43) for the Arkansas carrier (crude rate 0.9%) to 9.90 (95% confidence interval: 7.92-12.39) for the Empire carrier in New York area (crude rate 35.3%) compared with the Wisconsin carrier (crude rate 4.3%). There was also considerable variation among endoscopists; 75% of providers had no colonoscopies with anesthesia assistance recorded in their dataset, and 4.5% of providers had anesthesia assistance in at least three quarters of their examinations. Anesthesia assistance was not associated with the diagnosis of polyps, the performance of biopsy or polypectomy, or complications in multivariate analyses.

CONCLUSIONS

There are significant variations among regions and sites of service in anesthesia assistance during outpatient colonoscopies of Medicare beneficiaries. Although this variation has considerable economic implications, it was not associated with measures of patient risk or outcomes, such as polyp detection or procedure-related complications.

Sedation issues in quality colonoscopy

The subject of endoscopic sedation for colonoscopy remains controversial because of unresolved questions concerning the relative benefits, risks, and cost of service. There is also disagreement about the most appropriate sedation drug(s), delegation of responsibility for drug administration, and patient monitoring. This article examines recent trends in endoscopic sedation; the impact of sedation on the quality, safety, and patient tolerability of colonoscopy; and reviews the economic implications of current sedation practices.

Comparison of differing sedation practice for upper endoscopic ultrasound using expert observational analysis of the procedural sedation

AIM

To compare the quality between 2 commonly used sedation practices for upper endoscopic ultrasound (EUS) by using expert observational analysis of the sedation practice.

METHODS

After institutional review board approval, 50 adults undergoing EUS had videotape observation of the procedural sedation: 25 received benzodiazepine/opiate administered by the endoscopy team as per the standard protocol at our institution, and 25 received propofol administered by a dedicated anesthesiologist. Quantitative analysis of the video was performed using the Dartmouth Operative Conditions Scale (DOCS). The DOCS is a tool previously developed to quantify the adequacy of procedural sedation through an objective measurement of the patient state during the sedation process. In this study, the DOCS was used in a novel way to compare the quality of sedation provided by different sedation protocols. Data were collected on patient demographics, patient and provider satisfaction, efficiency, side effects, and safety measures.

RESULTS

Videotape analysis using the DOCS revealed that 52% (13/25) of the standard group exhibited an uncontrolled patient state (significant undersedation and/or oversedation) on 1 or more occasion during their EUS procedure compared with 28% (7/25) of the propofol group. Patients in the standard group spent 7.1% of the procedure in an uncontrolled patient state, whereas patients in the propofol group experienced an uncontrolled state approximately 1.0% of the procedure time. Overall efficiency as measured by time in both the procedure room and in recovery was superior in the propofol group. These patients spent 12 less minutes on average in the procedure room and were ready for discharge in about half the time (56 minutes versus 109 minutes). The propofol group experienced significantly less in-hospital and at-home nausea and vomiting and felt back to baseline status more quickly. Finally, patient satisfaction was improved in the propofol group: 60% felt the procedure was better than anticipated versus 21% in the standard group.

CONCLUSIONS

Expert videotape analysis of the patient state during procedural sedation allows direct comparison of sedation methodologies using small numbers of patients. In our institution, endoscopist-directed sedation using a midazolam/narcotic combination for EUS proved inferior to sedation using propofol given by an anesthesiologist. Specifically, a midazolam/narcotic combination provided less effective intraprocedural conditions, was less efficient both before and after the procedure, and was less satisfactory to patients as compared with propofol. Results of this type of analysis can be used to drive appropriate system redesign and improve patient care.

Anesthesiology and gastroenterology

A successful population-based colorectal cancer screening requires efficient colonoscopy practices that incorporate high throughput, safety, and patient satisfaction. There are several different modalities of nonanesthesiologist-administered sedation currently available and in development that may fulfill these requirements. Modern-day gastroenterology endoscopic procedures are complex and demand the full attention of the attending gastroenterologist and the complete cooperation of the patient. Many of these procedures will also require the anesthesiologist's knowledge, skills, abilities, and experience to ensure optimal procedure results and good patient outcomes. The goal of this review is (1) to provide a gastroenterology perspective on the use of propofol in gastroenterology endoscopic practice, and (2) to describe newer GI endoscopy procedures that gastroenterologists perform that might involve anesthesiologists.

Clinical trial: a randomized, study comparing meperidine (pethidine) and fentanyl in adult gastrointestinal endoscopy

BACKGROUND

There is little evidence to guide choice between meperidine (pethidine) and fentanyl for sedation for gastrointestinal endoscopy.

AIM

To compare meperidine with fentanyl in terms of procedure time and analgesia.

METHODS

Single centre randomized controlled trial. Patients received narcotic doses and midazolam at the discretion of the attending endoscopist who was unaware of narcotic assignment. Endoscopy and recovery times were then recorded. The main outcome was total procedure time, defined as endoscopy time plus recovery time. Patient discomfort was assessed prior to discharge via visual analogue scale (VAS).

RESULTS

In total, 55 patients were randomized to meperidine [44 colonoscopy and 11 esophagogastroduodenoscopy (EGD)] and 56 to fentanyl (45 colonoscopy and 11 EGD). Total procedure time was shorter for those receiving fentanyl (mean = 87.7 min) than for those receiving meperidine (mean = 102.9 min) (P = 0.05). The difference between the groups was explained by a shorter mean recovery time in the fentanyl group (63.0 min) than in the meperidine group (76.2 min) (P = 0.07). Based on post procedure pain scores, examinations with meperidine (mean = 1.99) were less painful when compared with those receiving fentanyl (mean = 2.86, P = 0.03).

CONCLUSIONS

Fentanyl shortened total procedure time by reducing recovery time. A simple change in narcotic choice could increase endoscopy unit efficiency.

Propofol use by gastroenterologists-the European experience

The administration of propofol as a sedative in gastrointestinal endoscopies became very popular in many European countries during the last years. Nevertheless there are huge regional differences in the way that the drug is used. Switzerland, the country with highest propagation of gastroenterologist guided propofol sedation, serves as a case study of its safe use in daily practice. The experiences of this spread are summarized in this article.

Endoscopic sedation: medicolegal considerations

The availability of endoscopy as a diagnostic and therapeutic tool has caused the number of procedures performed in the United States to greatly increase; additionally, the volume and complexity of endoscopic procedures performed under sedation, including difficult procedures performed on frail and severely ill patients, has increased. The goals of endoscopic sedation are to provide patients with a successful procedure and to ensure that they remain safe and are relieved from anxiety and discomfort; agents should provide efficient, appropriate sedation and allow patients to recover rapidly. Sedation is usually both safe and effective; however, complications may ensue. This article will explore medicolegal aspects of sedation, such as the importance of informed consent for sedation, the difficulties of assessing withdrawal of consent in a sedated patient, and the need for sedation monitoring which meets accepted standard of care. Controversies involving GI directed propofol and the use of anesthesia personnel to deliver sedation for endoscopy are also discussed.

Remifentanil compared with midazolam and pethidine sedation during colonoscopy: a prospective, randomized study

PURPOSE

The objective of our study was to compare the safety and efficacy of remifentanil during colonoscopy with those of the standard combination of midazolam and pethidine.

METHODS

One-hundred and sixteen consecutive patients scheduled for colonoscopy were randomly assigned to groups A or B. Patients in group A (n = 56) received intravenous (IV) midazolam and pethidine. Patients in group B (n = 60) received IV remifentanil.

RESULTS

Recovery was faster in group B (0 min) than in group A (56 +/- 11.3 min) (P < 0.001). There was a marked difference between groups B and A with regard to the time of hospital discharge-28.7 +/- 4.3 and 148.9 +/- 34 min, respectively (P < 0.001). Patients in group A rated the procedure as comfortable, as also did those in group B. A combination of midazolam and pethidine had a greater affect on patients' cardiorespiratory characteristics.

CONCLUSION

Remifentanil during colonoscopy provides sufficient pain relief with better hemodynamic stability, less respiratory depression, and significantly faster recovery and hospital discharge than moderate sedation with midazolam and pethidine.

Sedation for gastrointestinal endoscopy: the changing landscape

PURPOSE OF REVIEW

Most patients require sedation for gastrointestinal endoscopy. Moderate sedation for these procedures has traditionally been provided by the endoscopist with benzodiazepine and/or a narcotic. As endoscopy has increased in numbers and complexity, however, more effective sedation and analgesia is frequently required. Controversy has ensued over safe and efficient sedation practice. This review seeks to delineate what has been learned about this topic in the recent literature.

RECENT FINDINGS

There has been an increase both in the number of endoscopic procedures performed and in the use of propofol for endoscopic sedation. Studies have focused on several basic issues: alternatives to anesthesiologist-supervised propofol, other sedation regimens, and complications related to sedation.

SUMMARY

Alternatives to anesthesiologist-supervised propofol include nurse-administered propofol sedation supervised by the endoscopist, and patient controlled sedation. While other sedative regimens continue to be examined, the use of propofol for gastrointestinal endoscopy will continue to increase. Structured nurse-administered propofol programs appear to be safe, but the occurrence of severe respiratory depression and the ability to rescue remain concerns. Further study into appropriate sedation training, patient selection, ability to rescue, complications and value of anesthesiologist-directed sedation is necessary.

Practice efficiency and economics: the case for rapid recovery sedation agents for colonoscopy in a screening population

GOAL

To determine rapidly acting agents' impact on practice efficiency and cost for outpatient colonoscopy in a screening population.

BACKGROUND

Propofol-mediated endoscopic sedation is popular due to rapid sedation onset and superior recovery profile compared with sedation with an opioid and benzodiazepine. There are few data on the impact of this type of sedation on the economics and efficiency of an endoscopy unit.

STUDY

A provider-perspective economic model assessed the ability of propofol and fospropofol disodium (Aquavan, GPI 15715, MGI Pharma) to increase practice efficiency and determined break-even costs based on current colonoscopy reimbursement levels. Reimbursement inputs by practice setting, costs, and recovery profiles-taken from published literature examining time to discharge-were used to populate the model. To measure robustness of model results to changes in base case inputs, sensitivity analyses were performed. Using a Monte Carlo simulation, inputs were varied simultaneously and randomly for 1000 iterations to determine 95% confidence intervals (CI) for break-even costs.

RESULTS

In the time to complete 1 colonoscopy with midazolam/meperidine, 1.76 colonoscopies can be completed with propofol and 1.91 colonoscopies can be completed with fospropofol disodium. This efficiency benefit produced a break-even cost for rapid recovery agents of $71.53 (95% CI: $38.39, $105.67) in a hospital outpatient clinic and $61.48 (95% CI: $41.33, $108.99) in an ambulatory surgical center. One-way sensitivity analyses indicated the break-even cost of these agents was most sensitive to operating costs and time to discharge ratio.

CONCLUSIONS

Rapid recovery agents for colonoscopy can improve practice efficiency and offer economic advantages over traditional sedation.

Sedation in endoscopic practice

Sedation impacts every aspect of endoscopy practice--the quality fo the examination, the satisfaction of endoscopist and of patient, the efficiency and cost of delivering services, and the compliance of patients with surveillance guidelines. New sedation agents and improved patient-monitoring and drug-delivery technologies are challenging traditional practices. Increasing demand for endoscopic services, shrinking reimbursements, and competing diagnostic technologies are prompting recognition that new approaches to sedation can improve practice efficiency and patient outcome. This article discusses new developments in endoscopic sedation and their implications for practice management.

Sedation for endoscopic procedures: not as simple as it seems

The Bispectral Index (BIS) is a processed electroencephalogram, which has been evaluated as an automated monitoring technique for patients receiving sedation for endoscopic procedures. BIS monitoring has not been shown to be of significant clinical benefit, but the need for an objective quantitative measure of the depth of sedation in patients undergoing endoscopy remains.

The evolution of nurse-monitored sedation

The practice of nurse-administered sedation has evolved over the past decade. As the use of sedation increased and adverse events were reported, the need for guidelines to benefit patient safety became crucial. Guidelines have been issued from nursing organizations, medical organizations, and accrediting agencies that have the patient's safety as a priority. This article looks at the history of sedation and discusses how practice issues have evolved to the present day.

Anaesthesia and sedation for gastrointestinal endoscopy

PURPOSE OF REVIEW

Wide variations exist around the world in the practice of sedation for endoscopy, in terms of the depth of sedation, drug choices, delivery methods and the practitioners involved. These variations are driven by historical, cultural and economic factors. Professional bodies have promulgated guidelines in an attempt to unify and raise standards for sedation and monitoring. Nevertheless, preventable morbidity associated with sedation still occurs. A review of the recent literature is therefore justified.

RECENT FINDINGS

The main themes in this literature are the advent of the widespread use of propofol by non-anaesthesiologists, and particularly non-medical staff; novel methods for administering propofol; the acceptability of endoscopy without sedation; and emerging technologies that obviate the need for endoscopy.

SUMMARY

There is still much scope to research and refine sedation techniques for endoscopy. We believe that the involvement of anaesthesiologists in this research is vital.

Sedation and analgesia for gastrointestinal endoscopy during pregnancy

Endoscopy during pregnancy raises the unique issue of fetal safety. Endoscopic medications comprise a significant component of fetal risks from endoscopy. Before endoscopy, the gastroenterologist or anesthesiologist should evaluate the potential fetal risks of sedation and analgesia, identify any contraindications to endoscopy, stabilize the maternal medical status as necessary, and correct maternal hypoxia or hypotension. The mother should be informed about the potential teratogenic risks of endoscopic medications during pregnancy. Patients who receive sedation and analgesia should be monitored during endoscopy by continuous electrocardiography, continuous pulse oximetry, and intermittent sphygmomanometry, as well as by the pulse and respiratory rate. General principles of sedation and analgesia during pregnancy include use of the minimal effective dose, avoidance of unnecessary medications, and preferable use of Food and Drug Administration category B medications.

Propofol versus traditional sedative agents for gastrointestinal endoscopy: a meta-analysis

BACKGROUND & AIMS

Even though propofol has better recovery profile than traditional agents, its use is limited because of the perception of increased complication rates. Because an adequately powered trial comparing risk of propofol with traditional agents is lacking, we performed a meta-analysis of the current literature.

METHODS

We searched Medline (1966-October 2004), EMBASE (1980-October 2004), and Cochrane controlled trials registry. The following 4 cardiopulmonary complications were assessed: hypoxia, hypotension, arrhythmias, and apnea. Procedures were divided into 3 groups: esophagogastroduodenoscopy group, colonoscopy group, and endoscopic retrograde cholangiopancreatography/endoscopic ultrasonography group. Pooled odds ratios for complications were calculated for all the procedures combined and then separately for the 3 groups. Random effects models were used for 2-proportion comparisons.

RESULTS

Of the 90 citations identified, 12 original studies qualified for this meta-analysis and included 1161 patients. Of these, 634 received propofol, and 527 received midazolam, meperidine, and/or fentanyl. Most of the included studies were randomized trials of moderate quality and nonsignificant heterogeneity (Cochran Q = 4.81, P = .90). Compared with traditional sedative agents, the pooled odds ratio with the use of propofol for developing hypoxia or hypotension for all the procedures combined was 0.74 (95% confidence interval [CI], 0.44-1.24); for EGD, 0.85 (95% CI, 0.33-2.17); for colonoscopy, 0.4 (95% CI, 0.2-0.79); and for ERCP/EUS, 1.07 (95% CI, 0.38-3.01).

CONCLUSIONS

Propofol sedation during colonoscopy appears to have lower odds of cardiopulmonary complications compared with traditional agents, but for other procedures, the risk of complications is similar.