Nierenersatztherapie

Abstract

The clinical indications for initiating acute renal replacement therapy (ARRT) include life-threatening refractory disturbances of electrolyte, acid-base and fluid balances as well as severe clinical symptoms of the uremic syndrome. In most other cases a watch and wait strategy is justified; however, a consistent (at least daily) re-evaluation is mandatory. In intensive care patients with persistent oliguria or anuria for > 72 h despite stable hemodynamics and adequate volume status, initiation of RRT should be considered even in the absence of urgent clinical indications. For continuous RRT the guidelines recommend a total effluent volume (dialysate plus filtrate) of 20–25 ml/kg body weight/h which usually requires a higher prescription of effluent volume. The treatment duration and frequency of intermittent RRT should primarily be tailored to the patients’ individual needs regarding fluid, electrolyte, and acid-base balances. Treatment sessions every 2 days will usually be sufficient to achieve adequate solute clearance. Basic prerequisites for attempts at weaning from ARRT are stable hemodynamics, adequate fluid, electrolyte, and acid-base statuses and a urine output of at least 500 ml/24 h or a positive response to a furosemide stress test. The successful recovery of kidney solute clearance can be demonstrated by performing an endogenous creatinine clearance or quantification of the kinetic estimated glomerular filtration rate (KeGFR).