Evaluation of the efficacy of oral rehydration solutions using human whole gut perfusion.

Whole gut perfusion in humans was used to compare the effect on intestinal water and electrolyte transport of the World Health Organisation oral rehydration solution (solution II, composition in mmol/l: glucose 111, sodium 90, bicarbonate 30, potassium 20; 308 mOsm/kg); a hypertonic commercial oral rehydration solution (solution III, glucose 188, sodium 50, bicarbonate 20, potassium 20 mmol/l; 335 mOsm/kg); and three experimental bicarbonate free, hypotonic oral rehydration solutions: solution IV (glucose 111, sodium 60, potassium 20 mmol/l; 260 mOsm/kg), solution V (glucose 80, sodium 60, potassium 20 mmol/l; 219 mOsm/kg), and solution VI (glucose 80, sodium 30, potassium 20 mmol/l; 177 mOsm/kg). Perfusion of the intestine with a standard cleansing solution (solution I, sodium 125, potassium 10, bicarbonate 20, sulphate 40, mannitol 80 mmol/l; 275 mOsm/kg) confirmed published data on minimal water and sodium absorption. Experimental solution VI produced maximum water absorption (mean (SE) +1660.0 (29.8) ml/h) significantly greater than solution II (+1195.3 (79.5) ml/h), III (+534.7 (140.3) ml/h), IV (+1498.0 (42.7) ml/h), and V (+1327.7 (24.4) ml/h; p less than 0.05). Sodium absorption was significantly greater with solution II (+97.4 (7.9) mmol/h) compared to VI (+43.3 (7.8) mmol/h; p less than 0.01) but not compared to IV (+67.2 (13.0) mmol/h). A hypotonic oral rehydration solution such as solution VI may provide optimal replacement treatment for patients with acute diarrhoea.