IN mmol OUT mmol MB mmol Na 11296.8 11316.9 -20.1 K 235.3 272.1 -36.7 Ca 235.3 224.7 +10.6

Table 2: Same case of Table 1: example of direct measurement of electrolytes mass-balance obtained by spent dialysate partial collection. While sodium and potassium mass-balances may be considered adequate, calcium positive balance (corresponding to +424.7 mg) may be considered excessive.