Although, many of the familiar causes of hyperkalemia, including K-sparing diuretics, renal dysfunction, and adrenal insufficieny may be present in our cirrhotic patients as well, a poorly-functioning liver itself may be the culprit.

The liver, just as the muscle tissue, plays an important role in K uptake and serves as a buffer against serum K fluctuations. In a really cool experiment involving subjects given oral K supplements under controlled conditions (1), patients with cirrhosis had much greater bump in their serum K levels than normal controls despite similar weight, renal excretion of K and a significant rise in C-peptide levels. 

So even in the absence of usual risk factors, our cirrhotic patients may be more susceptible to hyperkalemia.

1. Decaux G, Soupart A, Cauchie P, et al. Potassium homeostasis in liver cirrhosis. Arch Intern Med 1988;148:547-8.