Hemodynamic response to fluid removal during hemodialysis: categorization of causes of intradialytic hypotension.

Background: Intradialytic hypotension is a clinically significant problem, however, the hemodynamics that underlie ultrafiltration and consequent hypotensive episodes has not been studied comprehensively.

Methods: Intradialytic cardiac output, cardiac power and peripheral resistance changes from pretreatment measurements were evaluated using a novel regional impedance cardiographic device (NICaS, NI Medical, Peta Tikva, Israel) in 263 hemodialysis sessions in 54 patients in dialysis units in the USA and Brazil with the goal of determining the various hemodynamic trends as blood pressure decreases.

Results: Hypotensive episodes occurred in 99 (13.