The accuracy of a continuous volumetric balancing system in pediatric continuous renal replacement therapy

Background: In pediatric continuous renal replacement therapy (CRRT) patients, accurate ultrafiltration (UF) measurement is essential, as both over-and under-UF may result in suboptimal outcomes. Traditionally, CRRT has relied on scale-based UF measurements; however, the recent development of a continuous volumetric balancing system has allowed for the advent of scale-less CRRT. Methods: To assess the accuracy of the volumetric balancing system, we designed a continuously measuring digital scale, which accounted for dialysate use and collected effluent, allowing us to independently measure UF volume and compare it with the machine reported UF volume. Results: In four low weight (6.9-16.7 kg) pediatric CRRT patients, we measured the UF volume over 20 separate runs, comprising a total of 318 hours. Over this time, the total measured UF volume was 50,550 mL +/- 296 mL, whereas the total reported UF volume was 50,733 mL, a difference of 183 mL +/- 296 mL (0.6 +/- 0.9 ml/h), or 0.4 +/- 0.6%. For each patient, over 48-112 hours per patient, the differences between the total measured and total reported UF volumes ranged from -7.8 +/- 1.7 ml/h to + 9.7 +/- 1.8 ml/h, or -6.0 +/- 1.3% to + 5.4 +/- 1.0%. Conclusions: In low-weight, pediatric CRRT patients, the scale-less continuous volumetric balancing system delivers accurate ultrafiltration.