Author: V. Dimov, M.D., Department of General Internal Medicine, Cleveland Clinic
76 yo male with DM2 on insulin, COPD, HTN, CKD is diagnosed with severe triple-vessel CAD and is here for preoperative evaluation for CABG. Serum creatinine has been 1.4-1.6 mg/dL for the last 2 years. The patient and his family are worried about worsening of his kidney function after the surgery.
What is his risk for developing ARF after cardiac surgery?
You can use a clinical score to predict the risk for ARF after cardiac surgery (Thakar et al, 2005).
Table 1. ARF score after cardiac surgery, modified from the original source. Used with author's permission.
|Risk Factor || |
| Female || 1 |
| CHF || 1 |
|LVEF <35%|| 1 |
| Preoperative use of IABP || 2 |
| COPD || 1 |
| Insulin-requiring DM || 1 |
| Previous cardiac surgery || 1 |
| Emergency surgery || 2 |
| Valve surgery only || 1 |
| CABG + valve || 2 |
| Other cardiac surgeries || 2 |
|Preoperative Cr 1.2 to 2.1|| 2 |
| Preoperative Cr 2.1 || 5 |
Risk score / Frequency of ARF-Dialysis
0–2 / 0.4%
3–5 / 1.8%
6–8 / 7.8%
9–13 / 21.5%
Our patient's risk is:
76 yo male with DM2 on insulin (1 point), COPD (1 point), HTN, CKD is diagnosed with severe triple-vessel CAD and is here for preop eval for CABG (2 points). Serum creatinine has been 1.4-1.6 (2 points) for the last 2 years.
1+1+2+2 = 6 points --> 7.8 % risk for developing ARF after surgery. This is higher than the usually reported frequency of postoperative ARF of less than 5%.
What are the risk factors for developing ARF after noncardiac surgery?
A study by Kheterpal et al. (Anesthesiology, 2007) listed the following 7 independent preoperative predictors for postoperatve ARF: age, emergent surgery, liver disease, body mass index, high-risk surgery, peripheral vascular occlusive disease, and chronic obstructive pulmonary disease necessitating chronic bronchodilator therapy. Several intraoperative management variables were independent predictors of ARF: total vasopressor dose administered, use of a vasopressor infusion, and diuretic administration.
The Department of Hospital Medicine and the Department of Nephrology at the Cleveland Clinic are currently conducting a study to develop a risk score for acute renal failure after noncardiac surgery (RANCS).
A clinical score to predict acute renal failure after cardiac surgery. Thakar CV, Arrigain S,Worley S, Yared JP, Paganini EP. Journal of the American Society of Nephrology 16(1):162-8, 2005.
Minimizing perioperative complications in patients with renal insufficiency (PDF). Martin J. Schreiber, Jr., MD, Cleveland Clinic. Cleveland Clinic Journal of Medicine, Proceedings of the Perioperative Medicine Summit, Suppl. 1 to Vol. 73, March 2006.
Acute renal failure - definition, outcome measures, animal models, fluid therapy and information technology needs: the Second International Consensus Conference of the Acute Dialysis Quality Initiative (ADQI) Group. Bellomo R, Ronco C, Kellum JA, Mehta RL, Palevsky P; Acute Dialysis Quality Initiative workgroup. Crit Care. 2004 Aug;8(4):R204-12. Epub 2004 May 24. Review.
Derivation and Validation of a Simplified Predictive Index for Renal Replacement Therapy After Cardiac Surgery. JAMA, 2007.
Predictors of Postoperative Acute Renal Failure after Noncardiac Surgery in Patients with Previously Normal Renal Function. Anesthesiology. 107(6):892-902, December 2007.
Acute Renal Failure in a General Surgical Population: Risk Profiles, Mortality, and Opportunities for Improvement. Anesthesiology:Volume 107(6)December 2007pp 869-870.