Plasmatic cystatin C for the estimation of glomerular filtration rate in intensive care units

OBJECTIVE: To compare the sensitivity of cystatin C and creatinine in detecting decreased glomerular filtration rate. DESIGN: Prospective observational study. SETTING: Medical intensive care unit at a university hospital. PATIENTS AND PARTICIPANTS: Fourteen patients hospitalised in a medical intensive care unit. INTERVENTIONS: Cystatin C and creatinine plasmatic levels were measured in 40 blood samples taken with an interval of at least 24 h. MEASUREMENTS AND RESULTS: Glomerular filtration rate was estimated by creatinine clearance using 24-h urine collection and the classical Cockcroft-Gault equation. The ability of cystatin C to detect a glomerular filtration rate under 80 ml/min per 1.73 m(2) was significantly better than that of creatinine ( p<0.05). CONCLUSIONS: Cystatin C, a new plasmatic marker of renal function, could be used to detect renal failure in intensive care in the future.