Effect of peritoneal fluid on whole body and segmental multiple frequency bioelectrical impedance in patients an peritoneal dialysis

Objective: We investigated the ability of whole body and segmental multiple frequency bioelectrical impedance (MFBIA) to detect peritoneal fluid in peritoneal dialysis patients. Design: Prospective study. Setting: Teaching hospital renal unit. Subjects: Patients on regular peritoneal dialysis. Interventions: Whole body and segmental MFBIA measurements before and after drainage of peritoneal fluid. Results: Changes estimated by MFBIA in total body water( - 0.4 (0.8) litres) and extracellular water(- 0.3 (0.3) litres) were much lower than the actual changes (2.0 (0.4) litres), P < 0.0001. Derived resistances R-ecf and R-icf increased significantly for the trunk but not for total body measurements and changes did not correlate with volumes of fluid drained. Conclusions: MFBIA is limited in its ability to detect intraperitoneal fluid, using both whole body and segmental techniques.