Systemic Levels of Cystatin C in Critically Ill Patients at risk for Acute Renal Failure.

Critically ill patients admitted in ICU are at high risk for developing acute
renal failure and 4-6% will require some form of renal replacement therapy.
Until now it is difficult to predict witch patient will develop acute renal
failure. Presently, the detection of ARF is primarily based on an increase of
serum creatinine concentration.
Cystatin C is a protein produced by all nucleated cells at a constant rate,
independent of age, gender and musclemass. It is completely filtrated in the
glomerulus and metabolized, but not secreted in the tubulus.
The serum CysC concentration has therefore been advocated as a marker of renal
function in non-ICU patients.

To evaluate whether (changes in) serum CysC concentration can be used as a
marker of renal function in a large cohort of critically ill patients, and to
describe the kinetics of CysC in these patients.

Prospective, observational, multi-center study.

Blood specimens are collected on the day of admission, every second day during
the first week, and 3-4 times per week thereafter until end of stay in ICU; per
sample 5 cc of blood is obtained. urine samples are collected at the same time
points