Transmembrane pressure modulation in high-volume mixed hemodiafiltration to optimize efficiency and minimize protein loss

The aim of the present study was transmembrane pressure (TMP) modulation in high-volume mixed hemodiafiltration (HDF) to optimize efficiency and minimize protein loss. The optimal flow/pressure conditions in on-line mixed HDF assisted with a feedback control of TMP were defined in this prospective randomized study in order to obtain maximal efficiency in solute removal while minimizing potential side effects. Two different TMP profiles in mixed HDF were compared in 12 unselected patients who underwent two study periods of 2 weeks each in cross-over randomized sequence: (A) constant TMP at around 300 mmHg and (B) profiled TMP, in which TMP was slowly increased from a low initial value to the maximal value. In both procedures, the mean volume exchange was 10.6±1.4 l/h. Mean filtration fraction was 53%. Instantaneous β 2-microglobulin ( β 2-m) clearance was higher at the start of the session with profiled TMP (207±35 vs 194±28 ml/min, P β 2-m clearance of the session (97.0±15.4 vs 87.8±18.3 ml/min, P P P