Does bioimpedance analysis or measurement of natriuretic peptides aid volume assessment in peritoneal dialysis patients?

Cardiovascular mortality remains the commonest cause of death for peritoneal dialysis patients. As such, preventing persistent hypervolemia is important. On the other hand, hypovolemia may potentially risk episodes of acute kidney injury and loss of residual renal function, a major determinant of peritoneal dialysis technique survival. Bioimpedance has developed from a single-frequency research tool to a multi-frequency bioelectrical impedance analysis readily available in the clinic and capable of measuring extracellular, intracellular, and total body water. Similarly, natriuretic peptides released from the heart because of myocardial stretch and increased intracardiac volume have also been variously reported to be helpful in assessing volume status in peritoneal dialysis patients. The question then arises whether these newer technologies and biomarkers have supplanted the time-honored clinical assessment of hydration status or whether they are merely adjuncts that aid the experienced clinician.