Comparison of Two Methods of Administration of a PEG Solution
Condition: Colorectal Cancer
MeSH terms: Colorectal Neoplasms
Study type: Interventional
Phase: Phase 4

Summary: 
      The purpose of this study is to compare the effectiveness (quality of bowel cleansing) and
      ease of use (patient satisfaction) of two methods of administration of a precolonoscopy PEG
      solution in hospitalized patients.
    

Detailed description: 
      Background and rationale of the research

      Colonoscopy is an endoscopic examination whereby the physician can visually inspect the
      interior lining of the colon. It is the most efficient and accurate means of identifying,
      either directly or by biopsy, neoplasms in the large intestine and inflammatory processes,
      infections, or ischemia involving the whole colon and the distal small intestines. In
      addition, during the procedure, certain endoscopic treatments may be performed, such as
      removal of precancerous polyps and cauterization of bleeding sites such as vascular
      malformations by electrocoagulation.

      Proper preparation of the bowel prior to colonoscopy is crucial to the quality of the
      examination. Suboptimal preparation can adversely affect the ability of the examiner to
      detect abnormalities in the small and large intestine or to carry out various endoscopic
      treatments. In some cases, poor preparation may necessitate canceling the procedure and
      rescheduling the patient for a repeated test.

      To properly clear the bowel, patients must strictly adhere to a special diet and drink a
      laxative solution as directed. The physician selects the specific type of laxative solution
      from among those that are currently available on the basis of the patient's age and
      underlying diseases. At present, polyethylene glycol (PEG), owing to its good safety profile
      and relative lack of complications, is recommended in older patients (65 years or more),
      patients with hypertension or renal or cardiac insufficiency, and patients being treated with
      diuretics and ACE inhibitors. However, a major disadvantage of PEG is its difficulty of use,
      which involves bad taste and drinking 3 liters within a short period of time on the day
      before the examination.

      Several recent studies in the medical literature have reported that in ambulatory patients,
      dividing the oral laxative solution into 2 doses taken at different times is more effective
      than drinking the whole amount in one session. On the basis of these findings, and given that
      the quality of the bowel preparation is known to be poorer in hospitalized than in ambulatory
      patients, we sought to determine if dividing the laxative dose will yield better results in
      hospitalized patients as well. It should be noted that laxative solutions constitute the most
      accepted method of preparing the bowel for colonoscopy and that in the present study, the
      sole difference from standard practice was the method of administration, namely a single or a
      split dose.

      Aim of the study The purpose of this study is to compare the effectiveness (quality of bowel
      cleansing) and ease of use (patient satisfaction) of two methods of administration of a
      precolonoscopy PEG solution in hospitalized patients.

      Method

      Study design: Prospective, comparative, randomized

      End points:

      Primary - Cleanliness of the bowel, as determined by the examiner, and ease of use, as
      determined by a patient satisfaction questionnaire in the two study arms Secondary - Effect
      of external factors (demographic parameters, length of hospitalization, procedural diagnosis)
      on the quality of the bowel preparation.

      Study sample: Four hundred hospitalized patients scheduled for a colonoscopy examination as
      part of their in-hospital work-up.

      Inclusion criteria: Age 18-80 years; ability to understand and complete the questionnaires;
      ability to participate in all stages of the research.

      Exclusion criteria: Previous colon surgery, previous endoscopic procedures under full
      anesthesia, known sensitivity to the PEG solution, terminal renal or cardiac insufficiency,
      inability to sign the informed consent form Colonoscopy: All patients will perform the
      precolonoscopy bowel preparation by one of two methods, according to the study design,
      followed by colonoscopy at the Gastrolenterology Institute of Rabin Medical Center

      Questionnaires:

      Demographic questionnaire - age, sex, weight, height, years of education Patient satisfaction
      questionnaire - ease of preparation and related symptoms In addition, physicians will rate
      the degree of bowel visibility after the procedure on a standard scale.

      Study design:

      The study sample will include hospitalized patients scheduled for colonoscopy. The physicians
      conducting the research will obtain informed consent from all candidates for the study prior
      to their enrollment.

      At onset of the study, the participants will complete a demographic questionnaire in the
      presence of a member of the research team. Items will include age, sex, height, weight, and
      years of education.

      Study participants will be randomly divided into 2 groups. Group 1 will receive the
      precolonoscopy PEG solution in a single dose of 3 liters in the evening preceding the test.
      Group 2 will receive half the dose (1.5 liters) of the identical solution in the evening
      preceding the test and the other half (1.5 liters) on the morning of the test. The
      randomization will be performed at the Gastroenterology Institute. The secretary of the
      Institute will then inform the nurses/attendants in the various hospitalization departments
      which of the two procedures to apply to each individual patient. Before the procedure, the
      patients will complete a demographic questionnaire in the presence of a member of research
      team. The physician performing the colonoscopies will be blinded to the group allocation.
      After completing the colonoscopy, the physician will rate the quality of the bowel
      preparation in the patient's medical file according to the Aronchick scale, as follows:

      Score Description 0 - excellent More than 95% of the intestines visible

        1. - good Large amount of transparent fluid requiring suction; more than 90% of intestines
           visible

        2. - fair Semisolid stool requiring suction/flushing; more than 90% of intestines visible

        3. - poor Semisolid stool difficult or impossible to remove; less than 90% of intestines
           visible

        4. - failed Repeated test required

      Following the procedure, study participants will be asked to rate their satisfaction with the
      ease of use of the bowel preparation and the severity of symptoms related to it (e.g.,
      stomach pain, nausea) on a VAS scale.

      Colonoscopy method:

      At the time of referral for colonoscopy, patients will receive a preliminary explanation of
      the test, of the alternative examinations currently available, and of any possible
      complications of the test. On the day of the colonoscopy, after receiving additional
      explanations from the attending gastroenterologist, patients will be asked to sign an
      informed consent form. The colonoscopy examination will be performed with patients lying on
      their left side; a sedative will be administered intravenously. During the procedure, the
      patient may feel cramping and discomfort from the infusion of air into the colon. The
      duration of the examination will about 30 minutes, depending on the structure of the colon,
      the amount of visibility consequent to the bowel preparation, and the degree of patient
      cooperation; the last two factors are essential for the success of the procedure. The
      endoscopic device will be carefully cleaned and sterilized between examinations in accordance
      with routine practice at our institute and accepted standards in developed countries.

      Statistical analysis

      On the basis of reported means and standard deviations in the medical literature, assuming a
      75% compliance rate and type 1 error (α) of 0.05, a study sample of 400 hospitalized patients
      will yield a statistical power of more than 80%. The sample will be divided into two
      treatment groups using the computerized Research Randomizer 2007 (http://www.randomizer.org/)
      Independent t test will be used to compare means of continuous variables between the two
      groups, and chi-square test will be used to compare proportions. Nonparametric Mann-Whitney
      test will be used to analyze the level of preparation and bowel cleanliness, ranked on an
      ordinal scale, between the groups. All test will be two-sided; statistical significance will
      be set at p<0.05. All analyses will be performed with SPSS software, version 15.

      Participating researchers

      Gastroenterology Institute: Dr. Ram Dickman, Dr. Gal Eyal, Dr. Zvidi Ibrahim, Dr. Ofer Ben
      Bassat, Dr. Wilkin Alexander, Dr. Zohar Levy, Dr. Michal Cohen, Dr. Gerald Fraser, Prof.
      Yaron Niv, Dr. Boris Sapoznikov, Dr. Irit Avni-Biran, Nechama Horev, Melli Mor, Negba Segal,
      Shlomit Flaut, Yafit Honen, Igor Bogoslavsky, Ilana Morad.

      Schedule

      The study is planned for a two-year period:

      Patient enrollment until mid-2009 Data collection and analysis until end 2008-beginning 2009

      Ethics

      Patient anonymity will be maintained.
    

Intervention name(s): PEG solution in a single dose of 3 liters; PEG solution
Intervention type(s): Drug; Drug
Intervention description(s): Group 1 will receive the precolonoscopy PEG solution in a single dose of 3 liters in the evening preceding the test.; PEG solution: half the dose (1.5 liters) of the identical solution in the evening preceding the test and the other half (1.5 liters) on the morning of the test
Other intervention name(s): Meroken New; Meroken New
Intervention MeSH terms: Pharmaceutical Solutions
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Colonoscopy; PEG Solution