Defining Chronic Kidney Disease in Primary Care: Management, Complications, Risk, Referral
Primary care clinicians have an essential role in the diagnosis and treatment of chronic kidney disease. Click through a review of the basics.
The prevalence of chronic kidney disease (CKD), estimated at more than 10% of the general population, is greater than the availability of nephrology specialists. For many patients, care is provided by primary care physicians (PCPs).
CKD care presents a number of challenges, but guidance geared to primary care physicians is offered by the National Kidney Disease Education Program, the Kidney Disease Outcomes Quality Initiative, and the Journal of Family Practice.
Click through the slides below for a brief overview of basics drawn from these resources.
Gaining clarity. A updated guideline in 2012 added care refinements based on cause, estimated glomerular filtration rate (eGFR), and albuminuria categories. CKD is defined as reduction of kidney function (eGFR of <60 mL/min/1.73 m2 for >3 months) OR evidence of kidney damage, including persistent albuminuria (>30 mg of urine albumin per gram of urine creatinine for >3 months). Defining CKD based on abnormalities in kidney function or albuminuria for ≥3 months distinguishes it from potentially preventable or reversible acute kidney injury for <3 months.
Disease difficulties. Outcomes can improve if CKD is addressed early, but CKD is underdiagnosed. Patients are unaware they have CKD, and conflicting guidelines may complicate physicians’ understanding of the disease. The biggest challenges primary care physicians face in providing CKD care: a broad range in disease severity and significant heterogeneity in the risks of progression to end-stage renal disease (ESRD), morbidity, and mortality. Overlap of care issues with those of type 2 diabetes (T2D) and hypertension present another challenge.
Key issues in CKD management. Guidelines provide primary care physicians with information and decision making assistance for optimal monitoring and management of CKD. The main management issues include ensuring the etiology is correct, implementing appropriate therapy, monitoring the patient, screening for CKD complications, and providing patient education.
Slowing CKD disease progression. Disease progression in CKD may be associated with high levels of albuminuria, progressive decrease in eGFR, and poorly controlled blood pressure. Identifying and slowing progression in high-risk patients is important even though patients with decreased eGFR or low grade albuminuria may not progress to kidney failure. With imprecise biomarkers for kidney function and damage, and variability among patients in disease progression, physicians are advised to predict prognosis based on a variety of clinical characteristics rather than a single measurement.
Common complications. Low eGFR increases the risk of systemic complications, mortality, and progression to ESRD. Common complications include cardiovascular disease (CVD) and dyslipidemia; anemia resulting from impaired erythropoiesis and low iron stores; mineral imbalance and bone disorder; hyperkalemia; metabolic acidosis; malnutrition; and fluid and salt retention. Complications occur more frequently and are more severe as eGFR declines.
CKD, CVD, and risk. For all patients with CKD, mortality risk from cardiovascular complications is 10-fold greater than the risk of reaching ESKD. All persons who have CKD should be considered at increased risk for CVD. Low eGFR and albuminuria are reported to be independently predictive of CVD and CVD mortality in addition to well-known Framingham risk factors for CVD. Anemia, mineral and bone disease, vascular calcification, and other CKD–specific risk factors seem to play a role in CVD in patients with CKD.
CKD and diabetes. CKD develops in about 40% of patients with T2DM, the leading cause of dialysis or kidney transplantation in the United States. Patients with diabetic kidney disease—CKD secondary to microvascular changes associated with diabetes—often present with long-standing T2DM, retinopathy, albuminuria without gross hematuria, and gradually progressive eGFR loss. In patients with diabetes and moderate to severe CKD, only about one-fourth are aware of their kidney disease.
