Jejunal dialysis in man using mannitol as the perfusate.

In four normal subjects a 50-cm segment of the jejunum was perfused through a multilumen tube with either hypertonic (1300 mOsm/kg) or isotonic mixtures of mannitol and water at rates between 18 and 70 ml/min. There was no difference in the solute clearances produced by the two solutions. Mean clearances (ml/min) were urea 23, creatinine 8, urate 4. Ninety-five mmol of sodium and 3.8 mmol of potassium were removed during a 1-h perfusion period. Clearances of glucose, calcium, phosphate and protein were negligible. Mean free water clearance was 0.5 ml/min during isotonic perfusion and 22.4 ml/min during hypertonic perfusion. These clearances of urea and creatinine are similar to those previously reported during perfusion of the whole bowel in uraemic patients with isotonic mannitol and during segmental jejunal perfusion with glucose/sodium mixtures. Over the range of flow rates studied there was a positive linear relationship between perfusate flow rates might achieve clinically useful solute clearance. However, the efficacy of the method in prolonged perfusion of uraemic patients may be different from that seen in normal subjects.