Colonic cleansing with sodium phosphate causes intravascular volume contraction in some patients.
In this study, researchers from Queen's University, Kingston, Canada, tested whether carbohydrate-electrolyte oral rehydration would attenuate the hypovolemic changes associated with administration of sodium phosphate.
The research team randomized 168 outpatients to ingest either regular clear fluids (n = 81), or a carbohydrate-electrolyte rehydration solution (n = 87), during precolonoscopy purgation by ingestion of aqueous sodium phosphate.
The investigators were blinded to the treatment assignment of patients.
They obtained clinical hemodynamic measurements and biochemical tests, both at baseline and after bowel preparation.
|Rehydration results in significantly less intravascular volume contraction.|
In addition, tolerability and colonoscopic visualization were assessed with questionnaires.
The research team discovered that rehydration resulted in significantly less intravascular volume contraction, when compared with clear fluids.
They also found that changes in estimated central venous pressure and orthostatic pulse were significantly greater in the clear fluid group versus the rehydration group.
Furthermore, changes in biochemical parameters after purgation also suggested a greater degree of volume contraction in the clear fluid group.
In addition, the team found colonoscopic visualization to be superior in the rehydration group.
However, the tolerability of the preparations was similar between groups.
Dr Robert Barclay's team concluded, "Carbohydrate-electrolyte rehydration protects against intravascular volume contraction during preparation for colonoscopy by ingestion of sodium phosphate".
In addition, "This approach is well tolerated by patients and improves colonic cleansing".