Although post-op renal function decrease is determined by serum creatinine, serum creatinine has disadvantages that it increases a long time after renal function decrease and it has various increasing time based on the level of renal function. Neutrophil Gelatinase-associated Lipocalin (NGAL's) usefulness as an evidence for acute kidney damage occurring from post-op cardiac surgery, being critical patients and contrast medium use is already proven.

But NGAL's usefulness for renal function after non-cardiac surgery is not proven and especially, NGAL's usefulness for renal injury after non-cardiac surgery in chronic renal disease patients is not proven.Therefore, the investigators will study about renal function decrease after non-cardiac surgery with NGAL and serum creatinine.

Inclusion Criteria:

• 43 patients who had non-cardiac surgery in Seoul Paik Hospital.

Exclusion Criteria:

• have viral hepatitis and Aspartate aminotransferase, Alanine aminotransferase > 2 time of normal level
• severe lung disease
• severe heart failure ( Ejection Fraction < 40% )
• pregnancy

43 patients who had non-cardiac surgery in Seoul Paik Hospital.