What the Primary Care Doctor Needs to Know About CKD

Chronic kidney disease is very common in clinical medicine, especially in patients with diabetes and hypertension. Recent evidence suggests that by the time overt findings such as proteinuria are present, the disease has advanced significantly. The presence of an elevated urine albumin creatinine ratio already signifies the presence of endothelial dysfunction and the potential for worsening kidney disease in non diabetics as well as in diabetics.

Though there are an estimated 19 million patients with chronic kidney disease, roughly 300,000 will require dialysis. The majority will succumb during earlier stages, predominantly due to a cardiovascular event. One health plan has documented that circulatory causes account for the majority of hospital charges in the six months prior to the initiation of dialysis.(Personal communication) Congestive heart failure is almost always associated with decreased renal function, and thus vigilant prevention of cardiovascular disease will reduce the risk of kidney disease and vice versa.

This is a synopsis of what primary care physicians can do to correctly manage patients with chronic kidney disease.

1. There are five stages of kidney disease. These are determined by successive measurements of the MDRD GFR over a three month period. Table 1 highlights these stages and Table 2 defines CKD. The MDRD GFR should be performed on each patient, and is based on the age, race, gender and serum creatinine. It is no longer necessary to include the albumin or the BUN. The formula is present at http://mdrd.com, and at http://nephron.com . http://nephron.com/physician has links to the NKF website, where physicians can download the GFR software for their PDA. These resources are based upon the Kidney Disease Outcomes Quality Initiative (K/DOQI) of the National Kidney Foundation.
2. All patients should be assessed for risk factors. Part 4 of the Guidelinesdiscuss the potential risk factors for developing CKD. Patients should be screened with a blood pressure, creatinine, urinalysis and urine albumin creatinine ratio. If CKD is suspected a renal ultrasound should be performed. The nephrologist and primary care physician should work together to determine a diagnosis, particularly if other than hypertension or diabetes, and if the disease can be treatable. The patient with documented CKD should always be questioned about relatives who may also have the disease.
3. After identifying and staging a patient, an action plan should be developed. The action plans for stages 1 and 2 (GFR > 60 cc/min) should emphasize preventive measures, maximize the use of ACE and ARB therapy, and strictly manage blood pressure and diabetes. Addition measures during this phase include determining and managing the underlying diseases, emphasize avoidance of nephrotoxic medications, and underscoring the institution of a program to reduce cardiovascular risk factors and their associated co-morbidities. Proteinuria has been documented to be toxic to the kidney, and evidence shows that titrating the urine proteinuria is possible with an ACE and/or an ARB. Though protein restriction is ideal, it is seldom possible in the real world, but education by a dietitian should help the patient avoid excessive portions of protein containing foods. In addition patients and members of the hospital phlebotomy team should work together to avoid damage to veins that might be the future site of an AV fistula. "Please be careful with my veins" is a simple handout developed for patients about to have blood drawn or an IV started.
4. Stage 3 (GFR < 60 cc/min) reflects advancing disease. Here there is a greater likelihood that the patient will have progressive disease, and it is in this phase that the morbidities and complications associated with decreased kidney function start to manifest. Patients in Stage 3 should be seen and co-managed by a nephrologist. Anemia, acidosis, low serum albumin and MBD (mineral and bone disease) develop during this and the next stage, and thus the primary care physician should be attentive to these problems, but work closely with the nephrologyst, who has a great deal of experience in dealing with each of the above issues. The primary care physician should continue to manage the patient with respect to diabetes, blood pressure, cardiovascular disease and as well other general medical conditions.

Clinical Performance Measures

The clinical performance of the primary care physician should include:

Stage 1 and 2

Screening patients at high risk - blood pressure, creatinine, MDRD GFR, UA, urine albumin creatinine ratio. The following patients should be referred to the nephrologist for consultation if:

• Stage 3 CKD
• The GFR is rapidly progressing
• One is uncertain of the etiology
• Overt proteinuria
• An active urinary sediment (casts, cells, crystals)
• Any autoimmune disease
• Malignant or refractory hypertension

All patients who have Stage 1 or 2 CKD (GFR > 60 cc/min) and beyond should have the objectives of:

• BP < 130/80
• HgbA1c < 7.0
• ACE or an ARB medications
• Titration of the urine protein albumin ratio to less than 30
• LDL and HDL management per ACC Guidelines

• Dietitian consultation (education regarding excess proteins, saturated fats, excess carbohydrates, sodium restriction, calorie restriction, health food substitutions)
• Renal education program that includes
  • Lecture on How the Kidney Works, What the Kidneys Do and What happens when kidneys fail
  • Medications to avoid
  • Vein preservation
  • Diabetes management
  • Cardiovascular risk factor management

• Pneumococcal vaccine and yearly flu shot
• Vitamin D level > 50 (may use ergosterol)
• Diabetic retina examination (if diabetic)
• Baseline KD Quality of Life Survey
• Echocardiogram
• Referral to nephrology when the MDRD GFR is less than 60 cc minute Stage 3)

Stage 3

Clinical performance measures by the nephrologists inlcude:

• Assessment for anemia - CBC, ferritin, iron saturation - Target Hgb 11 - 12 d/dL and institution of appropriate management
• Serum albumin of 4 g/dL
• Electrolytes - for metabolic acidosis and hyperkalemia (medications and diabetes)
• iPTH level in < href="">KDOQI range for stage (Stage 3 - 35-70, Stage 4 - 70 - 110)
• Vitamin D analog at stage IV
• Titration of proteinuria with an ACE or an ARB
• Follow up visits for renal education
• Dietitian consult
• Review of dialysis modalities
• Vein preservation education
• Education regarding the avoidance of toxic medications and substances
• Encourage exercise, cardiovascular risk factor prevention
• Diabetes management coordinated with the primary care physician

Stage 4

Continued management by the nephrologist of the above plus

Electrolytes (K and C0₂ in range)

A tour of the dialysis center - Modality education, including transplantation and home dialysis (PD and hemo)

KDQOL repeat

Vein mapping and referral to a surgeon experienced in placing AV fistulae

CKD-MBD management - PTH level, serum Ca and P management

Repeat echocardiogram

Disease manager

1. Review of blood pressure medications and patient follow-up to make sure BP < 130/80
2. Review of nutrition, medication, and education objectives, making sure they are being met
3. Follow up assessment of cardiovascular (and diabetes) status, diet and sodium status
4. Follow up and arrangement of KDQOL
5. Modality selection and tour of a dialysis center
6. Liaison between patient, primary physician, nephrologist, health plan medical director