A safe citrate anticoagulation protocol with variable treatment efficacy and excellent control of the acid–base status*

Abstract

We provide a safe and an easy-to-handle citrate anticoagulation protocol that allows an excellent acid-base and electrolyte control in critically ill patients with acute renal failure. The protocol can be adapted to patients' need, allowing a wide spectrum of treatment doses.

Regional Citrate Anticoagulation for RRTs in Critically Ill Patients with AKI

“…Therefore, in these protocols, the optimization of acid-base status and prevention/ treatment of metabolic alkalosis can be achieved by enhancing the diffusive removal of citrate and bicarbonate through increased flow rates of a low-bicarbonate dialysate. Conversely, as in the case of metabolic acidosis, an increase in the buffer supply to the patient can be achieved by increasing the citrate load throughout a parallel rise of blood and citrate flow rates (46). This approach permits flexibility in the management of acid-base status, but it may result in the development of metabolic acidosis if a high dialysis dose is required (high diffusive removal of buffers related to the increase of low-bicarbonate dialysate flow rate) (46,49).…”

“…RCA protocols based on hypertonic citrate solutions use citrate as the primary buffer, regardless of CRRT modality. In the case of continuous venovenous hemodialysis (CVVHD), a custom-made or commercially available low-bicarbonate concentration dialysate is commonly used to obtain a negative bicarbonate mass balance to compensate for the indirect bicarbonate load derived from citrate (46). Therefore, in these protocols, the optimization of acid-base status and prevention/ treatment of metabolic alkalosis can be achieved by enhancing the diffusive removal of citrate and bicarbonate through increased flow rates of a low-bicarbonate dialysate.…”

“…with exposure of patients to different electrolyte and buffer combinations, significantly affecting acid-base status and electrolyte balance during RCA (46,62,65,66). For the sake of simplicity, RCA solutions may be classified on the basis of citrate concentration as high-and lowconcentration solutions, with high citrate concentrations corresponding to hypertonicity with regard to sodium.…”

“…Although the use of standard sodium concentration CRRT solutions has also been reported in RCA protocols adopting hypertonic citrate formulations (68,69), these solutions are usually combined with customized low-sodium dialysis/replacement fluids to prevent hypernatremia. As long as a well designed protocol is implemented, hypertonic citrate solutions can be used to perform RCA with all modalities of CRRT ( Figure 2, Table 1) (15,16,18,46,47,49). RCA protocols based on hypertonic citrate solutions use citrate as the primary buffer, regardless of CRRT modality.…”

“…Citrate accumulation represents the most common complication of RCA, with a reported incidence of 0%-12% of patients depending on the RCA protocol used and the patient case mix (14,16,18,19,(44)(45)(46)(47)(48)(49)(50)(51). Because hepatic clearance represents the main metabolic fate of endogenous and exogenous citrate, citrate metabolism may be significantly slowed in clinical conditions where liver function is impaired, with a higher risk of citrate accumulation and consequent acid-base and electrolyte complications.…”