Background: The Genius dialysis system is a close loop dialysis batch system increasingly used as an intermittent hemodialysis device in intensive care units. The aim of this study was to test the safety and feasibility of a regional citrate anticoagulation protocol with respect to acid-base and electrolyte disarrangements in critically ill patients with acute renal failure. A standard heparin anticoagulation protocol served as control.
Methods and results: In a cross-over study design, 27 acute renal failure patients were allocated to a citrate- and heparin-anticoagulated dialysis sessions (4-6 h). For citrate anticoagulation, a 4% sodium-citrate solution was infused into the arterial line of the extracorporeal circuit. A low calcium dialysate (1 mmol/l) was used for all dialysis sessions. Citrate dosing was adjusted according to the post-filter ionized calcium concentration (targeted values 0.5-0.7 mmol/l). There was no routine calcium substitution. Heparin anticoagulation was started with a heparin-loading dose followed by an individual, patient-adjusted continuous heparin infusion. Electrolyte disarrangements, namely hypernatremia, hypo- and hypercalcemia did not occur in either group. Although the highest bicarbonate levels were achieved during citrate anticoagulation (p = 0.021 versus heparin) the acid base values remained equilibrated in both groups. Filter longevity was excellent and the targeted dialysis time was achieved in all but 1 patient. Citrate anticoagulation was well tolerated with respect to cardiovascular hemodynamics.
Conclusions: Citrate anticoagulation can be safely and effectively performed during intermittent Genius dialysis. Calcium supplementation is not routinely required.