GFR VS. CREATININEMeredith Mills, Corrie Phillips, Karen Porter and Andrea Sheley

College of Nursing, University of Oklahoma - 2010

Identification of the Problem

With increased use of contrast media (CM) in diagnostic and interventional procedures, contrast-induced nephropathy(CIN) has become one of the leading causes of hospital-acquired acute renal failure (Solomon 2006).

CIN is a complex syndrome of acute renal failure occurring after the administration of iodinated contrast media (Pucelikova 2008).

Identification of the Problem

The incidence of CIN in the general population is <2%, however, patients at increased risk, such as patients with diabetes with renal impairment, have a substantially greater risk, as CIN occurs in 12% to 50% of these patients (Aspelin 2005).

Other nonmodifiable risk factors include older age, congestive heart failure, hemodynamic instability, and nephrotic syndrome.

PICO Question

Does monitoring Glomerular Filtration Rate (GFR) instead of creatinine decrease the incidence of contrast-induced nephropathy (CIN) in adult patients age 35-75 undergoing cardiac catheterization?

Review of Literature-National Kidney Foundation

“Estimates of GFR are the best overall indices of the level of kidney function”.

The components used to estimate GFR are serum creatinine concentration, age, gender, race and body size.

Use MDRD Study equation to estimate GFR in adults.

Review of Literature- McCullough

Creatinine level changes were compared after administration of a IOCM versus LOCM.

Occurrence of CIN was 2% higher in all patients receiving LOCM versus IOCM.

Occurrence of CIN was 12% higher in CKD/DM patients receiving LOCM versus IOCM.

Review of Literature- Solomon CIN occurred in 421 of the 3112 renally

impaired patients. 9.5% with IOCM 9.0% with LOCM 19.9% with LOCM

Patients who were pretreated with N-acetylcysteine (NAC) had a 0-6% lower incidence of CIN.

Review of Literature- Aspelin European study that looked at the cost

of using IOCM vs. LOCM contrast media.

Study found the higher unit cost of IOCM is offset by the lower cost of treating fewer adverse reactions and therefore lower the total cost to the hospital.

Review of Literature- Nyman A risk factor model was produced that

took into account dosage/volume of contrast media along with risk factors.

Patients with 1:1 ratio, the risk of CIN was 3%.

Patients with greater than 1:1 ratio, the risk of CIN was 25%.

Review of Literature- Anderson Levels of serum creatinine were

measured pre- and post catheterization.

An association was NOT found between the amount of contrast used during angiography and the incidence of CIN in patients at initial high risk.

Review of Literature- Mehran A valid risk score model was developed.

13.1% of all patients in the study developed CIN.

57.3% of high risk patients developed CIN.

Eight independent predictors for developing CIN were identified.

Review of Literature- Mehran

Recommended Protocol

Standardized methods for calculating kidney function

Consistent use of a risk assessment tool prior to procedure

IOCM or LOCM Volume of contrast

Evaluation

Contrast Media vs. Patient Risk

Decreased adverse outcomes after cardiac catheterization:• Decreased number of patients with CIN• Decreased cost and length of hospital stay

Suggestions for Further Study

What exactly is the CM doing that is so harmful to the kidneys?

More definitive research on the maximal volume of CM.

Better understanding of preventative measures.

Evaluate the accuracy of the MDRD equation.

References

Anderson, J., Bair, T., Horne, B., Lappe, D., Madsen, T., Muhlestein, J., & Pearson, R. (2009). Risk of nephropathy is not increased by the administration of larger volume of contrast during coronary angiography [Electronic version]. Critical Pathways in Cardiology, 8, 167-171.

Aspelin, P., Aubry, P., Fransson, S., Strasser, R., Willenbrock, R., & Lundkvist, J. (2005). Cost-effectiveness of Iodixanol in patients at high risk of contrast-induced nephropathy. [Electronic version]. American Heart Journal. 149(2), 298-303.

McCullough, P., Bertrand, M., Brinker, J., & Stacul, F. (2006). A Meta-Analysis of the Renal Safety of Isosmolar Iodixanol Compared with Low-Osmolar Contrast Media. Journal of the American College of Cardiology, 48(4), 692-699.

Mehran, R., and et al. (2004) A Simple Risk Score for Prediction of Contrast- Induced Nephropathy After Percutaneous Coronary Intervention [Electronic version]. Journal of American College of Cardiology, 44, 1393-1399.

National Kidney Foundation. (2002) K/DOQI clinical practice guidelines for chronic kidney disease: evaluation, classification, and stratification. [Electronic version]. American Journal of Kidney Disease, 39, S76-92.

References Continued…

Nyman, U., Bjork, J., Aspelin, P., & Marenzi, G. (2008). Contrast medium dose-to-GFR ratio: A measure of systemic exposure to predict contrast-induced nephropathy after percutaneous coronary intervention. [Electronic version]. Acta Radiologica, 49(6), 658-667.

Odden, M., Shlipak M., & Tager, I. (2009). Serum creatinine and functional limitation in elderly persons [Electronic version]. Journal of Gerontology: Medical Journals, 64, 370-376.

Pucelikova, T., Dangas, G., and Mehran, R. (2008) Contrast- Induced Nephropathy [Electronic version]. Catheterization and Cardiovascular Interventions, 71, 62-72.

Solomon, R., & DuMouchel, W. (2006). Contrast Media and Nephropathy: Findings from Systematic Analysis and Food and Drug Administration Reports of Adverse Effects. [Electronic version] Investigative Radiology, 41(8), 651-660.