Snapshot A 56-year-old man presents to his primary care physician with shortness of breath and fatigue. He denies any chest pain but states that his wife noticed his legs appear swollen. Medical history is significant for hypertension and obesity. On physical exam there is dullness to percussion, decreased tactile fremitus, and dullness to percussion in the chest wall. There is pitting edema in the lower extremities. On laboratory testing, his glomerular filtration rate (GFR) 45 mL/minute/1.73 m2. Summary Clinical definition chronic kidney disease (CKD) describes abnormalities in kidney structure or function occuring for > 3 months e.g., glomerular filtration rate (GFR) < 60 mL/minute/1.73 m2 for > 3 months when CKD requires renal transplantation or dialysis, the patient is said to have end-stage renal disease (ESRD) Epidemiology incidence 1 in 10 American adults have some form of CKD risk factors older age diabetes mellitus hypertension acute kidney injury microalbuminuria or proteinuria overweight or obesity smoking, alcohol, and drug abuse Etiology insults that result in renal damage e.g., diabetes mellitus, autoimmune disease (such as lupus), and hypertension Pathogenesis in normal conditions the kidneys have the ability to maintain glomerular filtration rate (GFR) in the setting of nephron loss this is accomplished by hyperfiltration and hypertrophy of the remaining nephrons when GFR decreases to 50% there will be an increase plasma substances such as creatinine and urea a number of sequela occur as the GFR continues to decrease such as hyperkalemia metabolic acidosis normochromic normocytic anemia secondary to decreased synthesis of erythropoietin secondary hyperparathyroidism hyperphosphatemia hypocalcemia secondary to decreased hydroxylation of 25-hydroxyvitamin D to calcitriol impairment of sodium and free water excretion this results in extracellular fluid (ECF) expansion and total body volume overload this leads to peripheral and pulmonary edema and hypertension Presentation Symptoms typically asymptomatic in early stages of the disease clinical presentation secondary to uremia include fatigue nausea and vomiting pruritis chest pain secondary to pericarditis or pleuritis seizure Physical exam hypertension uremic frost growth retardation in children peripheral edema osteitis fibrosa cystica osteomalacia "renal rickets" Differential Acute on chronic kidney disease Studies Labs complete blood count (CBC) can see normochromic, normocytic anemia basic metabolic panel ↑ blood urea nitrogen (BUN), creatinine, and potassium ↑ phosphate ↑ parathyroid hormone ↓ calcium ↓ calcitriol cystatin C it is secreted but not reabsorbed an endogenous marker of renal function urine studies to assess for proteinuria can see waxy-casts on urinalysis in patients with ESRD and CKD Biopsy percutaneous renal biopsy is typically performed when there is renal impairment (or nephrotic range proteinuria) and the diagnosis is unclear after extensive workup Imaging Renal ultrasound indication considered the first-line imaging modality when working up a patient with CKD used to evaluate between obstructive and intrinsic parenchymal disease to assess for retroperitoneal involvement and renal cysts Treatment Conservative protein restriction indication a method of managing dietary protein that may reduce the rate of renal decline Medical ACE inhibitors or ARBs indications considered first-line for strict blood pressure control blood pressure goal of < 130/80 mmHg blood pressure control can help delay worsening of CKD to manage proteinuria in patients with diabetic kidney disease can worsen hyperkalemia vitamin D supplementation indication for prevention and treatment of secondary hyperparathyroidism erythropoiesis-stimulating agent indication can be considered to manage anemia in patients with CKD hemoglobin goal is 10-12 g/dL a complication from erythropoiesis-stimulating agents include hypertension headache phosphate binders indication to treat hyperphosphatemia in patients with CKD statins indication used as cholesterol lowering therapy in patients with CKD dialysis indication in patients with severe metabolic acidosis, hyperkalemia, pericarditis, intractable volume overload, and encephalopathy cardiovascular disease is the most common cause of death in patients on dialysis Operative renal transplant indication a treatment option for patients with CKD Complications Anemia Mineral and bone disease Hypertension Hypervolemia Depression Cardiovascular disease Prognosis typically progressive loss of renal function and may result in ESRD