Clinical management of kidney disease
The treatment goal for early-stage kidney disease is to address the risk factors that contribute to the progression of kidney disease: hypertension, heart disease, stroke, diabetes, and dyslipidemia. The TABLE reviews clinical management areas by disease stage.
Prescribe angiotensin antagonists. Angiotensin II receptor blockers (ARBs) and angiotensin-converting enzyme (ACE) inhibitors antagonize the toxic effects of increases in circulating angiotensin II and are therefore a key component of a therapeutic strategy to halt progressive kidney disease.2,21
Review medications, promote a healthier lifestyle. In addition to prescribing ARBs or ACE inhibitors, the family physician should review the CKD patient’s current medications to eliminate nephrotoxic drugs and adjust other medications on the basis of the patient’s creatinine clearance. Other measures include making sure vaccinations for influenza, pneumococcal pneumonia, and hepatitis B are up to date and emphasizing the importance of smoking cessation and exercise.
Treat comorbid conditions. Hypertension and diabetes must be treated aggressively. Patients with dyslipidemia should be managed with statins.2 Certain complications of progressive kidney disease, such as anemia, bone/mineral metabolic disease, and metabolic disorders, are typically treated by a nephrologist. Nevertheless, primary care providers need to understand these conditions in order to work together with the nephrologist in managing the CKD patient.
Check thyroid hormone and vitamin D levels. Understanding which factors predict disease progression or poor outcome is particularly useful. Most patients with CKD have low T3 syndrome, that is, low serum triiodothyronine levels in the absence of a thyroidal illness. In a recent paper, Song and colleagues showed that low T3 syndrome was common in early CKD and that estimated GFR was positively related with T3, independent of age and serum albumin.22
In another recent study, Ravani et al showed that plasma 25-hydroxyvitamin D is an independent, inverse predictor of disease progression and death in patients with stage 2 to 5 CKD.23 Vitamin D deficiency has been linked to CVD and early mortality in patients on hemodialysis.23 Checking for these 2 markers—low T3 syndrome and vitamin D deficiency—should therefore be part of your screening process for early stage CKD.
Refer to a dietitian. Dietary modification is another important component of the treatment plan. Dietary modifications are often needed to protect against CVD, help control blood pressure, reduce proteinuria, and improve metabolic control in patients with diabetes.2,24 Dietary modifications for CKD patients may go well beyond standard recommendations for a heart-healthy diet.2,24 Calcium, sodium, phosphorus, and potassium may need to be restricted according to laboratory values and stage of the disease.25 The KDOQI guidelines recommend referring CKD patients to a registered dietitian with experience in CKD for a complete nutritional assessment, comprehensive education on dietary restrictions and guidelines, and detailed dietary instruction.2
Manage CKD-associated anemia. Current guidelines do not propose normalizing hemoglobin in patients with renal disease, because lower levels of hemoglobin probably represent an adaptive response and correction to a “normal” level may disturb that response and lead to worse outcomes.26 For a discussion of management of anemia associated with CKD, see “Anemia and chronic kidney disease: What’s the connection?” in the January 2010 issue of this journal.27
Refer to a nephrologist early. A recent study by Chan et al demonstrates the beneficial effects of early referral to a nephrologist.28 There is no clear definition of early vs late referral and, at times, the only criterion is how much time elapsed before the patient was put on dialysis. Referral is considered “late” when management could have been improved by earlier contact with a specialist. It is probably prudent to refer stage 3 and 4 patients, at least for initial consultation. Chan’s meta-analysis found that patients referred late had nearly a 2-fold risk of death compared with those with early referrals. This risk persists at least up to 1 year after the initiation of renal replacement therapy.
Prepare patients for dialysis. It is very important that new hemodialysis patients present for initial treatment with an arteriovenous fistula in place, as first access for hemodialysis. Fistula placement is one of the most important reasons for timely referral to a nephrologist. Later referral is associated with a significantly prolonged hospital stay for initial renal replacement therapy. Late-referred patients are sicker, and many of the complications discussed here have not been optimally treated.
The optimal time to start preparing your patient for dialysis is when GFR measures between 15 and 29 mL/min/1.73 m2. Preparation includes counseling on nutrition and exercise, hepatitis B vaccination if needed, and scheduling for fistula placement.29