The results of our survey, consisting of responses from 288 members of the CAG and 55 members of the CSRCS, provide Canadian national data on the use of sedation for colonoscopy and concomitant monitoring practices. Information regarding the satisfaction of endoscopists with current sedative agents was also obtained. With 69% of CAG members responding to our survey, the demographics of our respondents were found to be very similar to those disclosed by CAG – the majority being men, practicing in a university- or teaching-based hospital, and based in Ontario, Alberta or Quebec. Hence, the CAG respondents were likely representative of all CAG clinician members.
An overwhelming majority of the respondents used intravenous sedation for most colonoscopies. This is consistent with the recommendations from Cancer Care Ontario’s Colonoscopy Standards Expert Panel (9
), which state that sedation should be offered to all patients undergoing colonoscopy. The Panel concluded that sedation leads to better outcomes in terms of greater patient cooperation, less patient memory of discomfort, reduction in reported pain and increase in patient tolerance of the procedure.
We found a lower use of intravenous sedation for colonoscopy at the free-standing endoscopy units than at the community hospitals. This finding may explain the higher rate of incomplete colonoscopy examinations and new/missed colorectal cancers found after colonoscopy at the free-standing endoscopy units in previous studies (8
). Although the relationship between use of sedation and rate of new/missed colorectal cancers needs to be directly evaluated in additional studies, a previous study (1
) suggested that the use of sedation can lead to higher colonoscopy completion rates and colonic polyp detection rates – surrogate markers of rates of subsequent new/missed colorectal cancers (11
). However, although we found lower use of sedation at the university hospitals, the same previous studies found no difference in outcomes for procedures performed at these facilities. These seemingly contradictory findings may be partially explained by the differences in the endoscopists practicing at university hospitals versus those at community hospitals or free-standing endoscopy units, and/or other systematic practice differences among the sites (eg, anecdotally, some university hospitals have longer slating times for each colonoscopy). We believe that individual free-standing endoscopy units can provide excellent care, but there is a need for more standardization for the care provided among different endoscopy units.
More than 80% of the respondents in the current survey used a combination of a benzodiazepine and a narcotic, of which midazolam and fentanyl were the most popular choice. This use pattern was similar to that reported in the US (3
), where more than 98% of colonoscopies are performed with intravenous sedation and more than three-quarters with a benzodiazepine and narcotic combination – midazolam and fentanyl being the most common. In contrast, fewer (only 76%) Swiss gastroenterologists used sedation for colonoscopy for more than 75% of cases (13
). The usual doses of midazolam and fentanyl used by the respondents were well within the range recommended in the US (less than 6 mg of midazolam and less than 200 μg of fentanyl) (14
) or in the UK (less than 5 mg of midazolam and less than 100 μg of fentanyl) (15
). We are not aware of similar Canadian guidelines for dosage of sedative agents for endoscopy.
We found that 13% of gastroenterologist respondents used propofol for routine colonoscopies, mostly administered by anesthesiologists. Propofol is used more frequently for colonoscopies performed in facilities other than the university hospitals. Interestingly, a geographical variation in practice was seen, with a higher proportion (23%) of respondents from Ontario using propofol for routine colonoscopies compared with 5% in the rest of the country. The use pattern for Ontario in our study was similar to that recently reported by Alharbi et al (16
) from an analysis of Ontario’s physicians’ billing claims database. They found that 19% of colonoscopies in 2005 in Ontario were performed with the assistance of anesthesiologists, which was used as a surrogate marker of the extent of propofol use. The similarity of the findings in the two studies provides face validity for our study.
The proportion of respondents (12%) in Canada in the current survey who used propofol was much lower than the 26% reported in a survey of US gastroenterologists in 2004 (3
). However, the involvement of anesthesiologists was similar to that in the US survey, in which in most instances (88%) propofol administration was directed by an anesthetist. There are obviously tremendous cost implications of this practice in both countries, especially when position statements from gastroenterology societies in both countries (17
) concluded that propofol can be safely administered by trained endoscopists.
We found that a higher proportion of adult gastroenterologists who used propofol routinely for all cases were highly satisfied compared with those using other agents. Approximately one-half of the gastroenterologists not currently using propofol would like to start using it. However, as much as Canadian endoscopists want to use propofol, and are as highly satisfied as they are with the use of the drug, a discordance remains because only one-third of adult endoscopists desired the use of the drug by itself or in combination for their own colonoscopy.
Both the CAG and the ASGE recommend that an individual in the endoscopy suite, whether an anesthetist or nurse, be solely dedicated to the monitoring of the patient if propofol is being used (18
). Our survey showed that two-thirds of adult endoscopists in Canada have only one nurse present in the endoscopy room during colonoscopy. Thus, if the CAG and the ASGE position statements were followed, wider implementation of propofol use would demand additional resources, resulting in increased costs to many health regions/hospitals because an additional individual would be required for cases involving propofol.
We are not aware of any studies comparing outcomes with different staffing patterns in endoscopy rooms. However, there is one study (involving 27,000 patients) from a group in Switzerland (20
) experienced with the use of propofol that reported an endoscopy team consisting of one physician endoscopist and one endoscopy nurse can safely administer propofol sedation for gastrointestinal endoscopy. The optimal staffing of endoscopy rooms (even in the setting of traditional sedative agents – narcotics and benzodiazepines) needs further study because there are huge cost implications with the number of health care providers in the endoscopy room. Anecdotally, administrators of some endoscopy units with more than one nurse in the endoscopy room are currently in the process of reducing staffing levels in their units purely as a cost-saving measure. We would caution against random reduction in endoscopy room staffing without concomitant careful evaluation of patient and procedural outcomes with different patterns of staffing.
Both the CAG and the ASGE recommend the use of pulse oximetry, blood pressure, continuous electrocardiogram and heart rate monitoring for patients receiving propofol (18
). Although more than 86% of adult endoscopists in our study used blood pressure and heart rate monitoring, and pulse oximetry for all colonoscopies, less than 11% used continuous electrocardiogram monitoring and less than 1% used capnography. Supplementary oxygen was provided for all colonoscopies performed by only two-thirds of the adult endoscopists. Thus, wider use of propofol, if the current guidelines are adhered to, will involve increased resource use and costs for monitoring during sedation for most endoscopy units.
Our study has many limitations. It was survey based and, hence, prone to nonresponse bias. However, the demographics of the gastroenterologist respondents were similar to those of the clinician membership of the CAG. All surveys are also subject to recall bias; however, there are no national or provincial databases in Canada that capture the information collected in the present survey. A Canadian system, similar to the Clinical Outcomes Research Initiative in the US, would provide valuable information. We have recommended that the CAG explore the feasibility of introducing such a system nationwide in Canada, which could also lead to an improvement in endoscopy reporting and allow easy, ongoing self-monitoring of their procedural process outcomes by the endoscopists. We did not have access to a database of general surgeons performing endoscopy in Canada and, therefore, did not survey most general surgeons, who are the primary providers of colonoscopy in rural Canada (21
). Our survey results, therefore, are not representative of the practice patterns of the use of sedation and concomitant monitoring in these parts of the country. The present study was descriptive in nature and, because comparisons among groups were not prespecified, the comparisons performed are subject to the fallacies of post hoc analysis and multiple statistical testing.