Management of acute renal replacement therapy in critically ill cirrhotic patients

Abstract

Renal replacement therapy (RRT) in cirrhotic patients encompasses a number of issues related to the particular characteristics of this population, especially in the intensive care unit (ICU) setting. The short-term prognosis of cirrhotic patients with acute kidney injury is poor, with a mortality rate higher than 65% in patients with RRT requirement, raising questions about the futility of its initiation. Regarding the management of the RRT itself, there is still no consensus with respect to the modality (continuous versus intermittent) or the anticoagulation required to improve the circuit life, which is shorter than similar at-risk populations, despite the altered haemostasis in traditional coagulation tests frequently found in these patients. Furthermore, volume management is one of the most complex issues in this cohort, where tools used for ambulatory dialysis have not yet been successfully reproducible in the ICU setting. This review attempts to shed light on the management of acute RRT in the critically ill cirrhotic population based on the current evidence and the newly available tools. We will discuss the timing of RRT initiation and cessation, the modality, anticoagulation and fluid management, as well as the outcomes of the RRT in this population, and provide a brief review of the albumin extracorporeal dialysis from the point of view of a nephrologist.

Keywords: AKI; cirrhosis; critical care; dialysis; epidemiology.

FIGURE 1:

Kaplan– Meier curve for 28-day mortality in critically ill cirrhotic patients requiring RRT compared with patients without RRT. Source: Reproduction of Figure of Staufer et al. [5]. Used with permission of the publisher.

FIGURE 2:

Components of CLIF-C-ACLF score, adjusted by age and white-cell count. Forty-eight hours after admission, a CLIF-C-ACLF score of ≥59.5 can predict ICU mortality with a sensitivity of 83.3% and a specificity of 85.7% [5] INR: international normalized ratio.

FIGURE 3:

Summary of RRT management in the critically ill cirrhotic patient. RRT: renal replacement therapy, sK: serum potassium, sHCO3: serum bicarbonate, AKI: acute kidney injury, uNGAL: urinary neutrophil gelatinase–associated lipocalin, PaFi: ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen, HRS: hepatorenal syndrome, BIS: bioimpedance spectroscopy, RBVM: relative blood volume monitoring, IRRT: intermittent renal replacement therapy, CRRT: continuous renal replacement therapy, INR: international normalized ratio, RCA: regional citrate anticoagulation.

FIGURE 4:

Differences between expected and occurred complications in patients with impaired liver function undergoing RRT with regional citrate anticoagulation. The incidence of the expected complication was based on the current knowledge of the metabolism of citrate, and was not estimated. Source: Adaptation of Figure of Klingele et al. [58].