Proatrial natriuretic peptide (1-98), but not cystatin C, is predictive for occurrence of acute renal insufficiency in critically ill septic patients.

INTRODUCTION: N-terminal prohormone of atrial natriuretic peptide ((proANP(1-98)) has been extensively analyzed in patients with chronic renal failure. It has been found to be closely related to the renal function and to interdialytic hydration status. The clinical relevance of proANP(1-98) and cystatin C, a novel marker of glomerular filtration, has not been investigated in the subgroup of critically ill septic patients with no history of chronic renal impairment. METHODS: We measured plasma level ofproANP(1-98) and cystatin C in 29 critically ill septic patients on admittance to the surgical intensive care unit and correlated it with the occurrence of acute renal failure. RESULTS: The proANP(1-98) plasma level was significantly higher in the group of patients who developed renal failure (12,722 +/- 12,421 vs. 2,801+/- 2,023 fmol/ml, p < 0.05). Multiple regression analysis shows that proANP(1-98) on the first day in the intensive care unit has a superior predictive value for the occurrence of renal failure to diuresis, calculated creatinine clearance or cystatin C (r = 0.42, p < 0.039). proANP(1-98) is also higher in non-survivors (9,303.8 +/- 11,053 vs. 2,448.5 +/- 1,803 fmol/ml, p < 0.018). CONCLUSION: proANP(1-98) is possibly a better predictor of acute renal failure to calculated creatinine clearance or diuresis among critically ill septic patients. Cystatin C was not correlated with occurrence of acute renal failure in this subgroup of patients.