End-Stage Renal Disease

Article Author:
Onecia Benjamin
Article Editor:
Sarah Lappin
Updated:
10/27/2018 12:31:33 PM
PubMed Link:
End-Stage Renal Disease

Introduction

More than 500,000 people in the United States live with end-stage renal disease (ESRD). The development of chronic kidney disease (CKD) and its progression to this terminal disease remains a major source of reduced quality of life and significant premature mortality. Chronic kidney disease (CKD) is a very limiting disease and standards of medical care involve aggressive monitoring for signs of disease progression as well as early referral to specialists for dialysis or possible renal transplant. KDIGO guidelines define CKD using markers of kidney damage, specifically markers that determine proteinuria and glomerular filtration rate. By definition, the presence of both of these factors (glomerular filtration rate [GFR] less than 60mL/min and albumin greater than 30mg per gram of creatinine) along with abnormalities of kidney structure or function for greater than three months signifies chronic kidney disease. End-stage renal disease, moreover, is defined as a GFR less than 15mL/min.

Etiology

End-stage renal disease can be caused by many chronic diseases. In the United States, diabetes is the leading cause. Other causes include hypertension, glomerulonephritis, polycystic kidney disease, prolonged obstruction of the urinary tract, vesicoureteral reflux, recurrent pyelonephritis, and certain medications such as NSAIDs, calcineurin inhibitors, and antiretrovirals.

Epidemiology

According to the United States Renal Data System, in 2015, there were 124,411 new ESRD diagnoses, reflecting an increasing burden of kidney failure. The prevalence of the disease has been rising at a stable number of about 20,000 cases per year.

The degree of kidney failure varies widely by race in the US. In 2015, the rate of ESRD was three times higher in African Americans as compared to Caucasians (393.5 versus 139.9 per million population). In that same year, the ESRD prevalence was about ten times higher in American Indians or Alaska Natives and twice higher in Native Hawaiians or Pacific Islanders. Rates were 1.3 times higher in Asian Americans. Of note, rates in the African American population have been decreasing each year since 2006, leading to an overall decrease of 21%. This reduction has been even more pronounced in American Indians/Alaska Natives.

Pathophysiology

The decline of kidney function is gradual and initially may present asymptomatically. The natural history of renal failure depends on the etiology of the disease but ultimately involves early homeostatic mechanisms involving hyperfiltration of the nephrons. As nephrons become damaged, the kidney increases the rate of filtration in the residual normal ones. As a result, the patient with mild renal impairment can show normal creatinine values, and the disease can go undetected for some time. This adaptive mechanism will run its course and will eventually cause damage to the glomeruli of the remaining nephrons. It is at this point that antihypertensives such as ACEs or ARBs may be beneficial in slowing the progress of the disease and preserve renal function.

History and Physical

End-stage renal disease can present with a constellation of signs and symptoms. Some include volume overload refractory to diuretics, hypertension poorly responsive to medication, anemia, mineral and bone disorders, and metabolic derangements including hyperkalemia, hyponatremia, metabolic acidosis, hypo/hypercalcemia, and hyperphosphatemia. Uremic toxicity also can present as anorexia, nausea, vomiting, bleeding diatheses, pericarditis, uremic neuropathy or encephalopathy, seizure, coma, and death. Uremic toxicity is an indication for urgent dialysis.

Evaluation

Chronic kidney disease is diagnosed when there is evidence of kidney damage for at least 3 months or in any patient who has a GFR less than 60 mL/min for that same amount of time.

To calculate GFR, three equations are commonly used (the MDRD, CKD-EPI and Cockcroft-Gault formula). However, the best estimate of GFR is the CKD-EPI equation, which adjusts for age, race, and gender.  It is important to note, however, that the formula tends to underestimate the true GFR at a GFR greater than 60mL/min.

To quantitate albuminuria, a spot urine protein/creatinine ratio can be done. A value greater than 30 mg of albumin per gram of creatinine is considered abnormal while values greater than 300mg/g is considered severely impaired renal function. Additionally, a 24-hour urine protein can also be performed. A value greater than 3.5 g is concerning for nephrotic range proteinuria.

Further evaluation of kidney disease can include a renal ultrasound, CBC, BMP, urinalysis, and/or kidney biopsy. An ultrasound can provide data estimating size, obstructions, stones, cystic renal disease, mass lesions, echogenicity, and cortical thinning. Blood work will determine if there is secondary anemia and will detect evidence of electrolyte derangement. In cases of severe anemia secondary to CKD, erythropoiesis-stimulating agents should be started at a hemoglobin level below 10g/dL.

Finally, a renal biopsy may be necessary if the etiology remains unclear.

Treatment / Management

Treatment of end-stage renal disease involves correcting parameters at the level of the patient presentation. Interventions aimed at slowing the rate of kidney disease should be initiated and can include:

  • Treating the underlying cause and managing blood pressure and proteinuria. Blood pressure should be targeted to a systolic blood pressure less than 130 mmHg and diastolic blood pressure less than 80 mmHg in both diabetic and non-diabetic adults whose urine albumin excretion exceeds 30 mg for 24 hours. For diabetics with proteinuria, an ACEI or ARB should be started in cases where urine albumin values range between 30 and 300mg in 24 hours and greater than 300 mg in 24 hours. These drugs slow the disease progression, particularly when initiated before the GFR decreases to less than 60 mL/min or before plasma creatinine concentration exceeds 1.2 and 1.5 in women and men, respectively.
  • Other targets in preventive care and monitoring should include tight glycemic control, cardiovascular risk reduction, and general lifestyle recommendations such as smoking cessation and dietary restriction. Glycemic control is critical. An A1C less than 7 is generally recommended to prevent or delay microvascular complications in this population. Management with sodium glucose transporter 2 (SGLT-2) inhibitors may reduce the burden of disease in those with Type II diabetes mellitus.
  • Treatment of chronic metabolic acidosis with supplemental renal bicarbonate also may slow the progression of end-stage renal disease.
  • Patients with CKD tend to have dyslipidemia, particularly hypertriglyceridemia. So monitoring with lipid panels and initiation of statins or other hypoglycemic agents can be started.  
  • Lifestyle modification and dietary restriction are recommended. Adhering to a low salt diet (less than 2 g/day), a renal diet (avoiding foods that are high in phosphorus), and restricting daily protein to 0.8g per kg body weight per day are essential to managing disease burden.
  • Hypocalcemia should also be monitored. A 25-OH vitamin D level less than 10 ng/mL warrants initiation of ergocalciferol 50,000 IU weekly for 6 to 8 weeks before switching to cholecalciferol 800 to 1000 IU daily.

Staging

KDIGO 2012: CKD classification takes into account the GFR level as well as the severity of albuminuria. It can be found on the KDIGO guidelines website.

Complications

Coronary Heart Disease is an important complication of chronic kidney disease and is the most common cause of death in this population. Patients on dialysis have a 10 to 30 times higher cardiovascular mortality risk than in the general population. The peripheral vascular disease is also commonly seen. It is associated with the following:

  • Hypertension
  • Mineral and bone disorders (secondary to hyperparathyroidism, vitamin D deficiency)
  • Hyperuricemia (urate concentration greater than 7) has been associated with adverse cardiovascular outcomes
  • Metabolic acidosis
  • Hyperphosphatemia
  • Hypoalbuminemia
  • Anemia

Pearls and Other Issues

  • ESRD is a terminal illness defined as having a glomerular filtration rate less than 15 mL/min.
  • The most common cause in the US is diabetic nephropathy followed by hypertension.
  • Other etiologies can include glomerulonephritis, cystic kidney disease, recurrent kidney infection, chronic obstruction, etc.
  • The disease can present with nausea, vomiting, metabolic, hematologic, electrolyte derangements, seizures, coma, bleeding diathesis, refractory fluid overload and hypertension unresponsive to pharmacotherapy, uremic pericarditis, etc.
  • Vigilant monitoring of GFR and proteinuria in diabetics and non-diabetics is essential for management of progression of disease in patients with chronic kidney disease.
  • Early referral to specialists is necessary as dialysis or renal transplant planning can be started immediately.