The clinical cases below illustrate specific teaching points in the preoperative care of patients with kidney disease:
Case 1: Does this patient need a stress test?
Case 2: Does this patient need a beta-blocker?
Case 3: When to correct hyperkalemia before surgery?
Case 4: When to do hemodialysis before surgery in patients with ESRD?
Case 5: Does this patient need an antibiotic before surgery?
Case 6: Does this patient need a blood transfusion?
Case 7: Which blood pressure medications to take on the morning of surgery?
Case 8: What is the risk for developing ARF after surgery?
Background information on preoperative care of patients with kidney disease
Why to do a preoperative evaluation?
More than 33 million surgeries are performed annually in the U.S., with 1 million patients sustaining medical complications after surgery, such as MI, CHF, stroke, pneumonia, respiratory failure, DVT, PE, delirium, or renal failure. Preoperative evaluation can save lives by preventing such complications.
What is the goal of the preoperative evaluation?
The goal of preoperative evaluation is to:
- determine the risk factors for increased cardiovascular mortality in the perioperative period
- modify the risk
- decrease morbidity and mortality
Preoperative evaluation follows the standard AHA/ACC algorithm, published on the website of the American College of Cardiology. There are 2 mnemonics that can be used to recall the main points in the algorithm: PAST and HIP.
There are 4 variables in the preoperative evaluation, remembered by the mnemonic PAST:
Activity level - measured in METs
Test (stress test) or Treat (beat-blocker)?
A patient with DM2, HTN, CAD s/p CABG with CHF is clearly at a higher risk than a patient who has only HTN.
Patient risk is assessed with the modified Revised Cardiac Risk Index (RCRI, Circulation, 1999;100:1043-1049):
Ischemic heart disease
History of congestive heart failure
History of cerebrovascular disease
Insulin therapy for diabetes
Preoperative serum creatinine higher than 2.0 mg/dL
4CD is a mnemonic to remember the risk factors in RCRI:
How well is the patient prepared for surgery? What is his activity level (measured in METs)?
The most useful question is "can you climb a flight of stairs without SOB or CP?" Going up the stairs, gives the patient a MET of 4, which is the dividing point in the algorithm to consider cardiac testing.
Just remember: "stairs = MET 4".
Distinguish between a high risk procedure, like AAA repair and a low risk procedure, like breast biopsy. Surgical procedures are classified in 3 groups according to the combined risk of cardiac death and nonfatal MI:
High surgical risk, cardiac risk more than 5%
Aortic and other vascular surgery
Prolonged procedures with large fluid shift/blood loss
Intermediate, cardiac risk less than 5% but more than 1%
Head and neck
Intraperitoneal and intrathoracic
Low, cardiac risk less than 1%
Even with the PAST mnemonic, the algorithm can still look complicated. Is there anything simpler?
Take the "HIP" Shortcut
Many patients have 1 or 2 risk factors from the RCRI and you can use the following shortcut to determine who needs a non-invasive cardiac testing, which in most cases is a stress test.
The shortcut to noninvasive testing is remembered by the mnemonic HIP:
H igh risk surgery, e.g. vascular surgery
I ndex risk factors -- 4CD (CAD, CHF, CVA, CKD, DM)
P oor functional class (METs less than 4)
If a patient has 2 out of 3 of the above variables, a stress test can be considered.
Note: The "HIP" shortcut is valid for patients who are scheduled to have high risk or intermediate risk surgery. Patients scheduled for low risk surgery can usually proceed with the operation without the need to have a stress test first.
Three Stress Tests
There are 3 stress test modalities which can be remembered by the mnemonic is EDD:
Exercise stress testing - without imaging or pharmacologic induction (both are used in the other 2 stress tests below)
Dipyridamole-thallium imaging (DTI)
Dobutamine stress echo (DSE)
Exercise stress testing limitations:
- OA patient who is unable to exercise
- Resting EKG abnormalities
DTI prognostic accuracy is 81%.
DSE has the additional advantage of showing the systolic function, the accuracy is similar to DTI.
Cut-off Numbers in the Algorithm
Remember the cut-off numbers 2-4-5 in the algorithm:
- 2 years of the last catheterization or a stress test - safe to proceed with surgery, if no symptoms
- 4 METs
- 5 years of the last coronary revascularization - safe to proceed with surgery, if no symptoms
Patients with Kidney Disease
How is their perioperative risk different from the "regular" patients?
We feature 8 short cases, each illustrating a specific teaching point. See the list at the top of the page.
CKD with Cr higher than 2 mg/dL is a part of the Revised Cardiac Risk Index that helps determine which patient may benefit from a beta-blocker.
No recommendation exists for a safe potassium level before surgery. Potassium less than 5.5 mEq/L is generally advisable.
Hemodialysis should be done the day before the surgery.
Antibiotic prophylaxis is recommended for several months after the placement of a synthetic graft.
Hemoglobin needs to be monitored and increased to a reasonable level (Hgb 10 mg/dL) preferably through the use of Epo. Blood transfusions may be needed.
ACEi, ARB and diuretics may lead to intraoperative hypotension, which subsequently may worsen renal function. Patients should not take these medications on the morning of the surgery.
Use a clinical score to predict ARF after cardiac surgery.
ACC/AHA Guideline Update for Perioperative Cardiovascular Evaluation for Noncardiac Surgery, 2007. Compare to 2002 version.
Perioperative Evaluation. Christopher M. Whinney. Cleveland Clinic Disease Management Project, 2009.
Preoperative Care of Patients with Kidney Disease. Mahesh Krishnan, M.D., M.P.H. Am Fam Physician 2002;66:1471-6.
Perioperative Management of the Patient With Chronic Renal Failure. Kenneth E Otah, MD, MSc, Moro O Salifu, MD, MPH, Eseroghene Otah, MD. eMedicine.com, last accessed 3/7/06
Minimizing perioperative complications in patients with renal insufficiency (PDF). Martin J. Schreiber, Jr., MD, The Cleveland Clinic. Cleveland Clinic Journal of Medicine, Proceedings of the Perioperative Medicine Summit, Suppl. 1 to Vol. 73, March 2006.
Perioperative medication management. Visala Muluk, MD, David S Macpherson, MD, MPH. UpToDate, 2006 (subscription required).
ABC of intensive care. Renal support. Clinical review. Alasdair Short, Allan Cumming. BMJ 1999;319:41-44 ( 3 July).
Preoperative Renal Risk Stratification. Glenn M. Chertow, MD, MPH; J. Michael Lazarus, MD; Cindy L. Christiansen, PhD; E. Francis Cook, ScD; Karl E. Hammermeister, MD; Frederick Grover, MD; Jennifer Daley, MD. Circulation. 1997;95:878-884.
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.
The Perioperative Management of Patients with CRF and ESRD. A Common Sense Approach. WalterReed.army.mil.
Medical management of the dialysis patient undergoing surgery. Ramesh Soundararajan, MD, FACP, Thomas A Golper, MD. UpToDate 14.1, 2006 (subscription required).
Anesthetic considerations for the patient with renal failure. Robert N. Sladen MB, ChB, MRCP, FRCP. Anesthesiology Clinics of North America, Volume 18, Number 4, December 2000. Link via MDConsult.com (subscription required).
Perioperative management of patients with chronic renal failure and postoperative acute renal failure. Kasiske BL. Urol Clin North Am - 01-FEB-1983; 10(1): 35-50. Link via MDConsult.com (subscription required).
Preoperative evaluation - 2010 National Guideline Clearinghouse.
New Risk Calculator for Prediction of Cardiac Risk After Surgery http://goo.gl/ayTv5 - Surpasses Revised Cardiac Risk Index (RCRI)?