No benefit of active preparations vs clear fluids before capsule endoscopy

Last Updated: 2016-08-01

By David L. Levine

NEW YORK (Reuters Health) - A clear-fluid diet is just as effective as polyethylene glycol (PEG) or sodium picosulfate plus magnesium (P/MC) as preparation for video capsule endoscopy, and the clear-fluids regimen is better tolerated, researchers say.

Dr. Lawrence C. Hookey of Queen's University and Hotel Dieu Hospital in Kingston Ontario, the lead author of the study, told Reuters Health by phone that in earlier studies, purgative preparations had been found to enhance visualization of the distal small bowel.

"Our findings dispute this as no significant benefit from active preparation was seen when the distal quarter of examinations were compared," he said.

As reported online July 20th in Gastrointestinal Endoscopy, Hookey and colleagues randomly assigned 198 adults with clinical indications for capsule endoscopy to preparation before the procedure with either clear fluids, two sachets of P/MC, or two liters of PEG.

All patients were instructed to stop any iron supplements five days before the examination. The day before, they were to have a light breakfast and lunch and then have clear fluids until midnight, and they were encouraged to consume at least eight 8-oz glasses of clear liquids over the day. After an overnight fast, the capsule was ingested in the morning between 8:00 and 8:30 am.

Outcome measures included scores on a 5-point ordinal cleanliness scale (the primary outcome), the percentage of time the small bowel view was clear, and a validated computerized assessment of cleansing "based on the intensities in the red and green channel of the tissue color bar of the reading station for each (capsule endoscopy)," according to the report.

In the 175 patients who completed the study, there was no clear benefit of either P/MC or PEG over clear fluids in the overall 5-point rating scale or in the distal quarter of each examination. Additionally, there was no difference in diagnostic yield between groups.

Compared with clear fluids, the average scores on the 5-point cleanliness scale in both the PEG and P/MC arms were lower by 0.4. Furthermore, there was no difference in time to first appearance of turbid fluid or degree of bubbles between the groups.

The computed analysis of cleansing of the preparations was not statistically significant between arms. However, when the examinations were divided into quarters, the score for P/MC was significantly lower than the scores for clear fluids only and PEG in the distal quarter (p=0.009).

The percent of time the view was clear was similar in the three groups.

There were, however, significant differences in tolerance of the preparations. The process was rated as easy or very easy by 93% in the clear fluids-only group compared to 67% in the P/MC group and 13% in the PEG group (p<0.0001).

P/MC was better tolerated than PEG (p<0.001). But the patients in the clear fluid-only group rated their preparation as having better taste than the other preparations, and they reported less nausea, abdominal pain, and bloating.

Dr. Hookey told Reuters Health, "Ours was one of the first studies to use a computerized assessment of cleansing, which we measured against traditional ways of studying using the 5-point scale. We found virtually no difference, meaning in the future clinicians may be able to just (use) computerized assessments which (are) less time intensive."

Still, he said, active preparation may be necessary for certain patients.

"We excluded patients likely to have a poor prep or incomplete examination, such as diabetics, inpatients, patients on narcotics, and those with severe motility issues," he said. "So we don't know about those patients. And there are limitations to visualization under ideal circumstances. Both in our study and in previous research the percent time obscured was still an average of 15% to 25%. This suggests that improvement in preparation regimens is still necessary."

Dr. Jonathan A. Leighton, vice-chair of the Department of Medicine at Mayo Clinic in Scottsdale, Arizona, told Reuters Health by phone, "This is a well done study that should make clinicians think twice about giving patients additional preps in addition to clear liquids."

At his institution, he said, "We have been using a 2L prep for patients undergoing small-bowel video capsule endoscopy based on previous studies that showed an advantage, including an increase in diagnostic yield. In my view, doctors should only be giving their patients additional preps if it improves diagnostic yield. This study suggests that there was no improvement in diagnostic yield with an additional prep. These results may influence clinicians to change their clinical practice and allow patients to be spared having to undergo preps for small-bowel video capsule endoscopy."

SOURCE: http://bit.ly/2ar20vJ

Gastrointest Endosc 2016.