Understanding modes of moderate sedation during gastrointestinal procedures: a current review of the literature

The efficacy of on-demand sedation colonoscopy: a STROBE-compliant retrospective cohort study

BACKGROUND

Colonoscopy has been routinely performed with sedation. Previous studies showed that on-demand sedation colonoscopy is acceptable in patients. We aim to compare the clinical outcomes of patients undergoing colonoscopy with and without sedation.

METHODS

A prospectively collected retrospective matched cohort study was performed. 290 consecutive patients who underwent colonoscopy without sedation were included into the study. Another 290 patients who underwent colonoscopy with sedation were then selected based on matched sex and age group distribution. Data were collected in a prospective database. Age, sex, race, and procedural variables were collected. Outcomes analyzed included adenoma detection rate, Boston bowel preparation scores, time spent in the recovery room, cecal intubation time, and presence of pain during colonoscopy.

RESULTS

A total of 580 patients were included in the study. Of the 290 patients who underwent colonoscopy without sedation, 10 patients (3.45%) required sedation to be administered to complete the scope. Intention-to-treat analysis was performed. Multivariate analysis demonstrated that the administration of sedation was a significant predictor of prolonged recovery time (increase in 34.76 min, 95% CI 29.56-39.55, p < 0.001). Comparing the group who underwent colonoscopy without sedation to the group who underwent colonoscopy with sedation, there was no statistically significant difference in mean cecal intubation time (11.28 vs. 10.38 min, p = 0.129), adenoma detection rates (25.1 vs. 35.8%, p = 0.060), percentage of patients who experienced no pain at all during the procedure (93.5 vs. 93.5%, p = 1.000), and Boston bowel preparation scores (2.23 vs. 2.34, p = 0.370).

CONCLUSIONS

Our data suggest that on-demand sedation colonoscopy can be performed in patients, with a significant decrease in time spent in the recovery room prior to discharge. Cecal intubation time, adenoma detection rates, and percentage of patients experiencing no pain at all during the procedure were similar in both groups of patients.

Sedation with propofol in digestive endoscopy administered by gastroenterologists. Experience in a Venezuelan hospital

OBJECTIVES

propofol is a rapid acting hypnotic that is becoming the drug of choice for sedation in digestive endoscopy worldwide. There is some controversy with regard to the use of propofol by physicians who are not anesthesiologists. We present our experience of the administration of propofol by endoscopist and nursing personnel.

METHODS

this was a retrospective study of sedation in endoscopy. Propofol was exclusively used and administered by the endoscopist who performed the procedure and the nursing staff. All patients included were of a low and moderate surgical risk (ASA I, II and III). No complementary medication was used such as benzodiazepines or opiates.

RESULTS

a total of 70,696 digestive endoscopy procedures performed between 2002 and 2017 were included in the study. Propofol was administered in an induction bolus of 10 to 50 mg, continuing with intermittent boluses of 10 to 20 mg, according to the patients' response. The incidence of complications was very low, assisted ventilation with a mask was required on 78 (0.11%) occasions. Only one case required endotracheal intubation and two patients had significant hypotension that required the administration of ephedrine. The average recovery time of all neuropsychomotor functions after the procedure was 15 minutes; 98% of patients reported a good or excellent level of tolerance and clearly remembered the details of the interview one hour after the procedure.

CONCLUSIONS

the use of propofol as a sedative in digestive endoscopy is a safe and effective technique, provided that it is administered and controlled by the endoscopist and nursing staff in properly selected patients. This allows gastroenterologists to achieve adequate sedation.

Safety of Propofol Used as a Rescue Agent During Colonoscopy

GOAL

The goal of this study was to evaluate the safety of propofol when used by gastroenterologists in patients who have an inadequate response to standard sedation (narcotics and benzodiazepines).

BACKGROUND

Many patients fail to achieve adequate sedation from narcotics and benzodiazepines during colonoscopy. The administration of propofol for colonoscopy is increasing, although its use by gastroenterologists is controversial.

STUDY

We performed a retrospective review of our hospital's colonoscopy records from January 2006 to December 2009 to identify 403 subjects undergoing screening colonoscopies who required propofol (20 to 30 mg every 3 min as needed) because of inadequate response to standard sedation. We also randomly selected 403 controls undergoing screening colonoscopies from the same time period that only required standard sedation. The incidence of adverse effects was then compared.

RESULTS

There were no major adverse events in either group. The rates of minor adverse events in the propofol and control group were 0.02 and 0.01, respectively (P=0.56). Adverse effects in the propofol group included: transient hypotension (n=1), nausea/vomiting (n=3), agitation (n=2), and rash (n=1). Adverse effects seen with standard sedation included: transient hypotension (n=2), nausea/vomiting (n=1), and oversedation (n=2). Patients who received propofol were more likely to be younger, had a history of illicit drug use, and a longer procedure time (P<0.05).

CONCLUSIONS

Adjunctive propofol administered by gastroenterologist for conscious sedation was not associated with increased incidence of adverse events. It may be of value in patients who do not respond to conventional sedation.

Effect of propofol anesthesia on force application during colonoscopy

BACKGROUND

Sedation is frequently used during colonoscopy to control patient discomfort and pain. Propofol is associated with a deeper level of sedation than is a combination of a narcotic and sedative hypnotic and, therefore, may be associated with an increase in force applied to the colonoscope to advance and withdraw the instrument.

OBJECTIVE

To compare force application to the colonoscope insertion tube during propofol anesthesia and moderate sedation.

DESIGN

An observational cohort study of 13 expert and 12 trainee endoscopists performing colonoscopy in 114 patients. Forces were measured by using the colonoscopy force monitor, which is a wireless, handheld device that attaches to the insertion tube of the colonoscope.

SETTING

Community ambulatory surgery center and academic gastroenterology training programs.

PATIENTS

Patients undergoing routine screening or diagnostic colonoscopy with complete segment force recordings.

MAIN OUTCOME MEASUREMENTS

Axial and radial forces and examination time.

RESULTS

Axial and radial forces increase and examination time decreases significantly when propofol is used as the method of anesthesia.

LIMITATIONS

Small study, observational design, nonrandomized distribution of sedation type and experience level, different instrument type and effect of prototype device on insertion tube manipulation.

CONCLUSIONS

Propofol sedation is associated with a decrease in examination time and an increase in axial and radial forces used to advance the colonoscope.

Bis(2,6-diisopropylphenyl) sulfite

In the title compound, C₂₄H₃₄O₃S, the dihedral angle between the benzene rings is 84.62 (8)°. In the crystal, inter­molecular C—H⋯O hydrogen bonds link mol­ecules into zigzag chains running parallel to the c axis. The C atoms of two isopropyl groups are disordered over two sets of sites with occupancy ratios of 0.858 (9):0.142 (9) and 0.61 (5):0.39 (5).

Perspectives on the role of fospropofol in the monitored anesthesia care setting

Monitored anesthesia care (MAC) is a safe, effective, and appropriate form of anesthesia for many minor surgical procedures. The proliferation of outpatient procedures has heightened interest in MAC sedation agents. Among the most commonly used MAC sedation agents today are benzodiazepines, including midazolam, and propofol. Recently approved in the United States is fospropofol, a prodrug of propofol which hydrolyzes in the body by alkaline phosphatase to liberate propofol. Propofol liberated from fospropofol has unique pharmacological properties, but recently retracted pharmacokinetic (PK) and pharmacodynamic (PD) evaluations make it difficult to formulate clear conclusions with respect to fospropofol's PK/PD properties. In safety and efficacy clinical studies, fospropofol demonstrated dose-dependent sedation with good rates of success at doses of 6.5 mg/kg along with good levels of patient and physician acceptance. Fospropofol has been associated with less pain at injection site than propofol. The most commonly reported side effects with fospropofol are paresthesia and pruritus. Fospropofol is a promising new sedation agent that appears to be well suited for MAC sedation, but further studies are needed to better understand its PK/PD properties as well its appropriate clinical role in outpatient procedures.

Endoscopic sedation of patients with chronic liver disease

Endoscopic procedures are often necessary in patients with chronic liver disease. The preprocedure evaluation of such patients should include an assessment of hepatic synthetic function and identification of neuropsychiatric findings suggestive of hepatic encephalopathy. It may be possible, in some cases, to perform diagnostic esophagogastroduodenoscopy without administration of sedation; this is desirable to eliminate the risks of sedation, especially encephalopathy. Nonetheless, most patients undergoing upper and lower endoscopy require sedation. Currently, the use of propofol is preferred to benzodiazepines and opioids for endoscopic sedation of patients with advanced liver disease due to its short biologic half-life and low risk of provoking hepatic encephalopathy. In appropriately selected patients, gastroenterologist-directed propofol administration seems safe.

Monitored anesthesia care (MAC) sedation: clinical utility of fospropofol

Fospropofol, a phosphorylated prodrug version of the popular induction agent propofol, is hydrolyzed in vivo to release active propofol, formaldehyde, and phosphate. Pharmacodynamic studies show fospropofol provides clinically useful sedation and EEG/bispectral index suppression while causing significantly less respiratory depression than propofol. Pain at the injection site, a common complaint with propofol, was not reported with fospropofol; the major patient complaint was transitory perianal itching during the drug's administration. Although many clinicians believe fospropofol can safely be given by a registered nurse, the FDA mandated that fospropofol, like propofol, must be used only in the presence of a trained anesthesia provider.

Fospropofol: a new sedative-hypnotic agent for monitored anesthesia care

OBJECTIVE

To summarize the published clinical data on fospropofol, critically review the safety and efficacy information, and provide pertinent information for formulary review.

DATA SOURCES

Data were collected from searches of MEDLINE (1966-June 30, 2009), EMBASE (1974-June 30, 2009), bibliographies of manuscripts, and www.fda.gov. Key search terms included fospropofol, Lusedra, Aquavan, sedative-hypnotic, and monitored anesthesia care.

STUDY SELECTION AND DATA EXTRACTION

All Phase 1, Phase 2, and Phase 3 clinical trials studying the safety and efficacy of fospropofol were reviewed.

DATA SYNTHESIS

Fospropofol is a water-soluble prodrug of propofol, a potent sedative-hypnotic agent. Propofol is highly lipophilic and is formulated in lipid-containing solvents, which have known disadvantages, including pain on injection, narrow therapeutic window with the potential to cause deep sedation, high lipid intake during long-term sedation, and risk of infection resulting from bacterial contamination. Due to its water solubility, fospropofol eliminates some of the known lipid emulsion-associated disadvantages of propofol and provides a more predictable peak onset of activity and more gradual recovery to a full state of consciousness. The pharmacokinetic and pharmacodynamic profiles of fospropofol make it an attractive agent for sedation for procedures of short duration. Unfortunately, the number of patients studied has been relatively small and the amount of safety data is limited. Of concern are reports of hypoxemia and hypotension; these reports are limited in number, but the episodes are serious and may require acute intervention. Although fospropofol holds promise for procedural sedation, due to limited safety data, the Food and Drug Administration has limited approval of fospropofol to monitored anesthesia care in patients undergoing diagnostic or therapeutic procedures.

CONCLUSIONS

Fospropofol is a viable addition to the class of sedative-hypnotic agents due to the minimization of unwanted adverse effects of propofol and maintenance of a favorable pharmacokinetic profile facilitating sedation, anxiolysis, and rapid recovery. However, there are limited safety data to justify its use without the presence of dedicated anesthesia personnel.

Endoscopist-directed administration of propofol: a worldwide safety experience

BACKGROUND & AIMS

Endoscopist-directed propofol sedation (EDP) remains controversial. We sought to update the safety experience of EDP and estimate the cost of using anesthesia specialists for endoscopic sedation.

METHODS

We reviewed all published work using EDP. We contacted all endoscopists performing EDP for endoscopy that we were aware of to obtain their safety experience. These complications were available in all patients: endotracheal intubations, permanent neurologic injuries, and death.

RESULTS

A total of 646,080 (223,656 published and 422,424 unpublished) EDP cases were identified. Endotracheal intubations, permanent neurologic injuries, and deaths were 11, 0, and 4, respectively. Deaths occurred in 2 patients with pancreatic cancer, a severely handicapped patient with mental retardation, and a patient with severe cardiomyopathy. The overall number of cases requiring mask ventilation was 489 (0.1%) of 569,220 cases with data available. For sites specifying mask ventilation risk by procedure type, 185 (0.1%) of 185,245 patients and 20 (0.01%) of 142,863 patients required mask ventilation during their esophagogastroduodenoscopy or colonoscopy, respectively (P < .001). The estimated cost per life-year saved to substitute anesthesia specialists in these cases, assuming they would have prevented all deaths, was $5.3 million.

CONCLUSIONS

EDP thus far has a lower mortality rate than that in published data on endoscopist-delivered benzodiazepines and opioids and a comparable rate to that in published data on general anesthesia by anesthesiologists. In the cases described here, use of anesthesia specialists to deliver propofol would have had high costs relative to any potential benefit.

Colonoscopy: Art or science?

The focus on colorectal neoplasia has led to an exponential increase in the use of colonoscopy in many countries. Although colonoscopy facilitates the diagnosis and treatment of colonic disease, there are public health issues that include access, training, diagnostic accuracy, complications and additions to health-care costs. Because of this, colonoscopists have a responsibility to ensure that the procedure is appropriate, safe and of high-quality. This article addresses the issue of variation in technical skills that is known to exist within the endoscopic community, even among individuals with similar experience. While some of this variation reflects innate manual dexterity, another aspect is variation in the adoption of technical manoeuvers that facilitate various aspects of the procedure including rates for cecal intubation. Although technical manoeuvers are difficult to evaluate in controlled trials, there is persuasive data that high cecal intubation rates can be achieved by minimizing inflation and looping in the sigmoid colon and by the appropriate use of positional changes and abdominal pressure. In difficult settings, there is also benefit from the use of non-standard endoscopes and various accessories including overtubes.