AbstractsMedical & Health Science

Continuous renal replacement therapy (CRRT) is increasingly applied in critically ill patients with acute kidney injury who requires renal support. CRRT is often preferred to intermittent dialysis because of better hemodynamic stability and metabolic control. Regional citrate anticoagulation (RCA) during CRRT (RCA-CRRT) is a common alternative to systemic heparin anticoagulation, especially by patients with increased bleeding risk. Indeed, in recently published guidelines RCA is now recommended as the anticoagulation strategy of choice in patients undergoing CRRT without contraindication to citrate. According to KDIGO guidelines, the major contraindications for RCA are: severely impaired liver function or shock with muscle hypoperfusion, both representing a risk of citrate accumulation. Citrate accumulation is a serious complication of CRRT with RCA. It could cause severe metabolic acidosis, decrease cardiac contractility or cause arrhythmias, as symptoms of systemic ionized hypocalcemia. Acute or chronic impaired liver function, shock with arterial hypoxia and reduced tissue perfusion are the major risk factors for citrate accumulation. Unfortunately measurement of citrate concentration in blood is not available on a daily routine basis, and, at least in Germany, available test kits are not approved for clinical use. There are however commonly accepted markers for citrate accumulation, such as: metabolic acidosis with or without increased anion gap, ionized hypocalcemia with simultaneous increased levels of total calcium and, an increased total calcium to ionized calcium ratio (tCa/iCa). Those laboratory parameters do not confirm citrate accumulation in all cases, and often lead to false positive results, what makes the diagnosis of citrate accumulation a complex clinical issue. More over, information about the incidence of citrate accumulation in general cohort of ICU patients undergoing RCA-CRRT is relatively limited, due to the fact that patients with risk factors for citrate accumulation were usually whether excluded from the prospective trials, or the observation of those patients were limited to the study period. In this monocentric retrospective study we collected and analyzed all patients on RCA-CRRT over a three-year period (from 2008 to 2010) to identify risk factors for citrate accumulation. The primary objective was to reveal the incidence rate of citrate accumulation in cohort of non-selected critically ill patients receiving RCA-CRRT. The secondary objective was to assess the clinical characteristics and outcome related to citrate accumulation based on a representative population of patients. The results of the present research show that the incidence of metabolic disarrangements consistent with citrate accumulation was rather low since it affected only 2.99% of all RCA-CRRT patients. Our findings show that RCA during CRRT is feasible and complications are uncommon independently of a liver function, shock or presented muscle hypoperfusion. Diagnosis of citrate accumulation was found exclusively in…