Coronary Angiography | Risk Equation for Contrast Associated Nephropathy

 

Definition of contrast-associated nephrotoxicity: increase in serum creatinine by >= 0.5 mg/dL (>= 44 µmol/L) during the 48 hours following administration

 

Contrast medium used: low osmolar nonionic

 

Parameters:

(1) hydration fluid

(2) initial serum creatinine

(3) gender of the patient

Parameter	Finding	Points
hydration fluid	isotonic normal saline (0.9 % sodium chloride)	1
	hypotonic saline (0.45% sodium chloride)	0
gender	male	0
	female	1

 

Z =

= (1.36 * (points for gender)) + (1.89 * (baseline serum creatinine in mg/dL)) – (1.18 * (points for hydration fluid)) – 4.9

 

probability of contrast media-associated nephropathy =

= 1 / (1+ EXP((-1) * Z))

 

Limitations:

• The upper limit of normal for serum creatinine was not given.

• The use of a contrast medium with a higher-osmolarity would be expected to increase the risk of nephropathy.

• Hydration fluids other than isotonic normal saline and half-normal saline are not represented. In light of the findings, it would seem that isotonic normal saline or its equivalent should be used as the hydration fluid.