Propofol for sedation during colonoscopy
Abstract
This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:
The primary aim of this review is to identify and summarize the available data from randomized controlled trials comparing the use of propofol to traditional agents for sedation during colonoscopy in terms of its relative effectiveness, acceptance and safety. Our secondary goal is to identify and summarize the data from randomized controlled trials comparing the administration of propofol by anesthesiologists to non‐anesthesiologists for sedation during colonoscopy.
Background
Most patients prefer the use of sedation and analgesia during colonoscopy (Subramanian 2005). Traditionally sedation during colonoscopy has been provided by the combination of a narcotic and a benzodiazepine. In recent years propofol (2, 6‐di‐isopropylphenol) has increasingly been utilized as an alternative method of sedation in endoscopy suites (Faulx 2005). Propofol was initially introduced in 1989 and has since then been widely used in critical care units and emergency departments for providing sedation. Although, propofol is associated with a more rapid onset of action and a shorter recovery time, its use by non‐anaesthologists in many parts of the world (particularly North America) has been limited by concerns of potential side‐effects. Large case series suggest that nurses and endoscopists can safely administer propofol for endoscopic procedures (Rex 2005; Walker 2003). There have been several small randomized controlled trials (RCTs) comparing propofol with traditional agents for sedation during colonoscopy (Bright 2003; Hansen 2004; Kostash 1994; Kulling 2001; Lee 2002; Lee 2002a; Moerman 2003; Ng 2001; Paspatis 2002; Reimann 2000; Roseveare 1998; Rudner 2003; Sipe 2002; Ulmer 2003). However these trials have enrolled small number of patients and could have failed to detect significant differences due to lack of adequate sample size and power.
Objectives
The primary aim of this review is to identify and summarize the available data from randomized controlled trials comparing the use of propofol to traditional agents for sedation during colonoscopy in terms of its relative effectiveness, acceptance and safety. Our secondary goal is to identify and summarize the data from randomized controlled trials comparing the administration of propofol by anesthesiologists to non‐anesthesiologists for sedation during colonoscopy.
Methods
Criteria for considering studies for this review
Types of studies
All randomized controlled studies comparing
1) Use of propofol vs. traditional agents for sedation during colonoscopy
OR
2) Delivery of propofol by anesthesiologists vs. by non‐anesthesiologists for sedation during colonoscopy
Types of participants
All adult patients undergoing colonoscopy
Types of interventions
1) Propofol vs. traditional agents for sedation during colonoscopy
2) Anesthesiologist vs. non‐anesthesiologist administration of propofol for sedation during colonoscopy.
Types of outcome measures
Patient satisfaction and pain control
Technical performance of colonoscopy: cecal intubation rate, time required for performing the procedure and post procedure recovery time
Complication rates: cardio respiratory events (hypoxia, apnea, endotracheal intubation, hypotension, arrhythmias), colonic perforations and hospital admission rate after procedure (when procedure performed in ambulatory care setting) and death
Search methods for identification of studies
The following electronic databases will be searched: MEDLINE and CANCERLIT via PubMed (National Library of Medicine), EMBASE, CINAHL, LILACS, Biological Abstracts, Web of Science and the Cochrane Central Register of Controlled Trials from January 1980 to June 2006. The year 1980 will be selected as the cut‐off as propofol was discovered in 1970's and introduced in clinical practice in 1980's (Marik 2004).
The following search strategy will be used for PubMed and adapted to suit the other databases:
1. Colonoscopy [MeSH]
2. colonoscop* OR sigmoidoscop*
3. #1 OR #2
4. Propofol [MeSH]
5. propofol OR diisoprofol OR diprivan OR disoprivan OR disoprofol OR rapinovet OR recofol OR diisopropylphenol
6. #4 OR #5
7. #3 AND #6
Owing to the relatively small number of articles in this field, we have omitted using an automated randomized control trial (RCT) filter in the search strategy; instead we choose to use the more sensitive approach of confirming RCTs manually.
Using the same terms, we will hand search the indices of conference abstracts from Digestive Diseases Week, the American College of Gastroenterology and the United European Gastroenterology Week between 1990 and 2005, published in the journals Gastroenterology, Gastrointestinal Endoscopy, American Journal of Gastroenterology, Gut and Endoscopy. We will also search reference lists of eligible RCTs.
Data collection and analysis
One investigator will review the titles and abstracts of retrieved studies to identify randomized controlled trials involving use of propofol during colonoscopy that meet the inclusion criteria for the type of interventions and participants listed above. Full text manuscripts of potentially relevant studies will then be reviewed and data abstracted by two authors working independently of each other. We will attempt to arrange for translation of potentially relevant non‐English articles through the Cochrane Colorectal Cancer Group. Any discrepancy between the reviewers will be resolved by joint re‐review of the studies and consensus. All potentially eligible, but ultimately excluded trials will be listed in the final report, along with the reasons for exclusion.
Data abstraction:
Following data will be recorded on customized paper forms:
1) Interventions evaluated
2) Sample size, number of participants randomized
3) Study site (s), including whether the colonoscopy was performed as an in‐patient or in the ambulatory care
4) Inclusion and exclusion criteria
5) Baseline characteristics of the study groups including the endoscopic findings
6) Mode of administration of the drugs‐‐‐bolus, infusion or mixture of both
7) Use of supplementary oxygen as part of the study protocol for all participants in the trial
8) Sedation level/scores‐‐‐‐
If a measurement scale was used, the scale used will be recorded as well as whether the scale had been previously validated
For the maximum levels of sedation in each group, the mean score as well as the standard deviation will be recorded
9) Overall patient satisfaction outcome‐‐‐
If a measurement scale was used, the name of the scale, whether the scale had been previously validated and the time after procedure when the scale was administered would all be noted.
Mean score in each group
Standard deviation of score in each group
10) Patient pain control outcome‐‐‐‐‐
If a measurement scale was used, the name of the scale and whether the scale had been previously validated would be noted.
Mean pain score in each group
Standard deviation of pain score in each group
11) Technical performance of colonoscopy
a) Procedural completion: Number of patients in whom cecum could be reached in each group and number of patients in whom cecum could not be reached in each group
b) Procedure duration: mean and standard deviation in each group
c) Recovery from sedation
i) How the recovery time was defined; mean time and standard deviation in each group
ii) If a measurement scale was used, the scale used will be recorded as well as whether the scale had been previously validated; time after the procedure when the testing with the measurement scale was performed; mean and standard deviation on the scale in each group
12) Complication rates: Number in each group who had the following complication and number who did not have the complication
a) Hypoxia (oxygen saturation less than 90%)
b) Apnea
c) Hypotension (systolic blood pressure less than 90)
Mean (and standard deviation) drop in Blood pressure in each group will be noted
d) Arrhythmia
e) Colonic perforations
f) Hospital admission after procedure (when procedure performed in ambulatory care setting)
g) Death
13) Data adjustment methods‐what method were used to adjust for potential confounding factors.
Study quality assessment:
1) Allocation concealment: adequate, unclear, inadequate or not used
2) Blinding: whether the patients, endoscopists and outcome assessors were unaware of assigned intervention?
3) Was there a description of withdrawals and dropouts?
Data analysis:
Overall patient satisfaction, patient pain control, procedural time and recovery time after the procedure will be evaluated as continuous outcomes. Standardized mean difference will be calculated for the overall patient satisfaction and pain control. Mean differences will be calculated for the procedural and recovery times and the maximum drops in blood pressure. Both fixed effect method (Inverse Variance approach) and random effects method (DerSimonian and Laird approach ‐ DerSimonian 1986) will be used.
Odds ratios will be calculated for the dichotomous variables: procedural completion rate and individual complications. Both fixed effects model (Mantel‐Haenszel ‐ Mantel 1959) and random effects model (DerSimonian and Laird method‐ DerSimonian 1986) will be used.
Forest plots will be used to display the (standardized) mean difference and ORs of individual studies.
Heterogeneity between the studies will be evaluated with the Q statistic. Possible sources of the encountered heterogeneity including differences in the conduct of trials will be explored.
Sensitivity analysis will be performed by excluding studies published in only abstract form and by excluding studies which had utilized non‐validated measurement scores. Sub group analysis, if possible will be performed for studies where all colonoscopies were performed as an outpatient procedure, studies where propofol was used alone without additional agents in one of the arms of the study, for each specific traditional sedative used and studies with and without patient controlled propofol administration.
