Briefly describe a specific question, or set of related questions, about a health care test or treatment that this program should consider.

a. For patients undergoing elective colon and rectal surgery, what is the role of oral mechanical bowel preparation?

• It has been “historically proven” that mechanical bowel preparation is necessary to cleanse feces from the bowel and decrease the bacterial load thereby decreasing wound infection and anastomotic leak rates. Over the last 20 years many small, randomized prospective trials have challenged this dogma. Meta-analyses of these trials indicate that oral mechanical bowel preparation is at best equal to no oral mechanical bowel preparation and may be harmful. Despite the data, surgeons have been reluctant to change their practices. Bowel preparation has been eliminated in some centers in Canada, Europe and the United States. The lowest risk anastomoses are those involving an ileo-colonic anastomosis and bowel preparation has been eliminated most readily for those operations with surgeons being most reluctant to eliminate bowel preparation for colo-colonic and colorectal anastmoses. This is due to the belief that the bacterial load in small bowel is lower than that in colon so that ileocolonic anastomoses are “safer”. There is no data comparing indications for surgery so that colectomies for inflammatory bowel disease have not been differentiated from colectomies for cancer or diverticular disease. There is data from the trauma literature that indicates that repair of colonic injuries in the setting of an acute injury is safe. There does not appear to be a difference between preparation types and impact on benefit of mechanical bowel preparation, or lack thereof, in Canada or Europe compared to the United States.

Does your question include a comparison of different health care approaches? (If no, your topic will still be considered.)

yes

If yes, explain the specific technologies, devices, drugs, or interventions you would like to see compared:

Oral mechanical bowel preparation versus no oral mechanical bowel preparation in elective colon and rectal surgery.

What patients or group(s) of patients does your question apply to? (Please include specific details such as age range, gender, coexisting diagnoses, and indications for therapy.)

This question applies to all patients undergoing elective colon and rectal surgery. There are no studies in children. The lack of information in children is a knowledge gap. All races and both genders are included. Conditions requiring surgical intervention include inflammatory bowel disease (Crohn’s and ulcerative colitis), diverticular disease of the colon, colon and rectal cancer, and ischemic and infectious colidites.

Are there subgroups of patients that your question might apply to? (For example, an ethnic group, stage or severity of a disease.)

Yes. Elderly patients and patients with chronic disease may be more susceptible to the electrolyte disturbances and dehydration engendered by mechanical bowel preparation. Further, the elderly, infirm and non-compliant are less able to self administer the preparation and may require admission preoperatively for placement of a nasogastric tube for delivery of the preparation.

Describe the health-related benefits you are interested in. (For example, improvements in patient symptoms or problems from treatment or diagnosis.)

a. Avoidance of unnecessary stomas (ileostomies/colostomies), avoidance of reoperation for stoma closure

• Decrease in surgical cancellation rates, which currently happens when a patient has not taken the prescribed oral bowel prep.
• Fewer nausea, vomiting, dehydration, electrolyte abnormalities and possible secondary cardiopulmonary complications.
• Lower requirement for intra-operative fluid resuscitation of the dehydrated patient leading to less bowel edema, less hypothermia and possibly fewer leaks.
• Easier on patient – quality of life improvement the night before surgery and potentially shorter lengths of stay

Describe any health-related risks, side effects, or harms that you are concerned about.

a. Anastomotic leak, wound infections, pneumonia, prolonged hospital stay

• Decrease in bowel preparation related nausea, vomiting dehydration and electrolyte abnormalities

Appropriateness for EHC Program

Does your question include a health care drug, intervention, device, or technology available (or likely to be available) in the U.S.?

yes

Which priority area(s) and population(s) does this topic apply to? (check all that apply)

EHC Priority Conditions (updated in 2008)

• Cancer
• Infectious diseases, including HIV/AIDS

AHRQ Priority Populations

• Low income groups
• Minority groups
• Women
• Children
• Elderly
• Individuals with special health care needs, including individuals with disabilities or who need chronic care or end-of-life health care

Federal Health Care Program

• Medicaid
• Medicare
• Other

Importance

Describe why this topic is important.

Patients undergoing elective colon and rectal surgery are typically prescribed an oral mechanical bowel preparation prior to surgery. This preparation has been “historically proven” to be necessary. Patients report that it is unpleasant and is associated with nausea and vomiting. Clinical side effects include electrolyte abnormalities and dehydration and can contribute to cardiopulmonary complications in the postoperative period. Over the last 20 years, multiple small, randomized prospective trials, primarily conducted in Europe, and at least three meta-analyses have suggested that the practice is at best equal to no oral mechanical bowel preparation, and in fact may be harmful. Despite mounting evidence North American surgical practices have not changed. Furthermore, patients undergoing surgery on other organ systems (gynecology, urology, vascular surgery) are often prescribed oral mechanical bowel preparation as well. Surgeons performing these operations, which involve risk of inadvertent injury to the colon and rectum, believe that repair of an injury in unprepared bowel is unsafe and would require a stoma.

What specifically motivated you to ask this question? (For example, you are developing a clinical guideline, working with a policy with large uncertainty about the appropriate approach, costly intervention, new research you have read, items in the media you may have seen, a clinical practice dilemma you know of, etc.)

Some surgeons have been swayed by the meta-analysis that oral mechanical bowel preparation should be discontinued. Mark Welton presented at national meetings regarding this and the audience seemed to agree the data behind no oral mechanical bowel preparation is convincing. However, very minimal practice change has been seen. A great majority does not want to change their practices until a large randomized prospective North American trial is conducted or other more compelling evidence is presented. Dr. Welton proposed to our society, The American Society of Colon and Rectal Surgeons that we nominate this topic for an AHRQ EPC evidence review and we have received agreement that a practice parameter will be published citing the results of this review.

Does your question represent uncertainty for clinicians and/or policy-makers? (For example, variations in clinical care, controversy in what constitutes appropriate clinical care, or a policy decision.)

yes

If yes, please explain:

North American surgeons do not trust European studies for “historical” reasons and fears of poorly done studies. These physicians are struggling with the historical dogma surrounding the utility of oral mechanical bowel preparation. They await validation in a population that may be generalized to their own.

Potential Impact

How will an answer to your research question be used or help inform decisions for you or your group?

The ASCRS has agreed to publish a new practice recommendation or guideline citing the results of this review and other studies as supporting evidence to abandon oral mechanical bowel preparation. We will use this data to support funding of a large multicenter randomized prospective trial should that be suggested.

Describe the timeframe in which an answer to your question is needed.

Small prospective clinical trials continue to be published that challenge the issue without definitively answering the question due to lack of statistical power. Elective colon and rectal surgery and all the other procedures for which patients receive either an oral mechanical bowel preparation or a stoma, are common procedures performed daily across the country. If the leak rate or wound infection rate is altered positively or negatively we are actively harming patients because some surgeons have eliminated bowel preparation, while others have not and one group of surgeons is incorrect. Thus, this issue should be addressed in a short time frame. Further, since the adverse sequelae related to oral mechanical bowel preparation typically occur within 30 days of the index operation, if a large multi-center trial is proposed, a one-year period of study should suffice to demonstrate changes in anastamotic leak rates; wound infection rates; consequences of dehydration and electrolyte disturbances.

Describe any health disparities, inequities, or impact on vulnerable populations your question applies to.

Minority patients and under-insured patients tend to cluster for care in hospitals, which are under resourced and possibly understaffed. There may be no fellowship-trained specialists in these community hospitals. In some cases, particularly in non-academic settings, practitioners may be less likely to follow evidence based practice guidelines.

Nominator Information

Other Information About You: (optional)

Please choose a description that best describes your role or perspective: (you may select more than one category if appropriate)

The ASCRS has agreed to publish a new practice recommendation or guideline citing the results of this review and other studies as supporting evidence to abandon oral mechanical bowel preparation. We will use this data to support funding of a large multicenter randomized prospective trial should that be suggested.

Are you making a suggestion as an individual or on behalf of an organization?

Organization

Please tell us how you heard about the Effective Health Care Program

Kathryn McDonald