8.6 Chronic Kidney Disease
Chronic kidney disease (CKD) refers to the gradual, progressive loss of kidney function over time. As kidney function declines, the ability to remove excess fluids and filter wastes from the blood becomes impaired. Additionally, electrolyte imbalance and hormone production may also be compromised.
CKD typically progresses slowly over months or years and is asymptomatic in the early stages. As kidney function continues to decline, symptoms like fatigue, swelling in the legs and ankles, difficulty concentrating, decreased appetite, and changes in urination patterns may begin to emerge.
Pathophysiology and Risk Factors
There are many potential risk factors for developing CKD. Older adults, individuals with a family history of CKD, and certain ethnic groups such as African Americans, Hispanics, and Native Americans have an increased risk of developing CKD. Factors that decrease blood flow to the kidneys, such as atherosclerosis, diabetes, and high blood pressure, can damage the kidneys. Urinary tract disorders like glomerulonephritis (inflammation of the kidneys’ filtering units), polycystic kidney disease, kidney stones, prolonged urinary tract obstruction, and recurrent urinary tract infections can also cause damage. Other risk factors include autoimmune diseases and chronic long-term use of certain medications such as nonsteroidal anti-inflammatory medications and antibiotics.[1]
CKD is classified by health care providers by stages according to the individual’s glomerular filtration rate (GFR). The stage of CKD guides medical treatment. See Table 8.6a for an overview of the stages of CKD.[2]
Table 8.6a. Stages of CKD
| Stage | Description | GFR (mL/min/1.73 m²) |
|---|---|---|
| 1 | Normal GFR | 90 or higher |
| 2 | Mild reduction in GFR | 60 – 89 |
| 3 | Moderate reduction in GFR | 30 – 59 |
| 4 | Severe reduction in GFR | 15 – 29 |
| 5 | Kidney failure (End-stage) | Less than 15 |
Assessment
CKD affects multiple body systems due to the kidneys’ crucial role in regulating fluids, electrolytes, and hormone levels. See Table 8.6b for an overview of clinical manifestations of CKD by body system.
Table 8.6b. Signs and Symptoms of CKD by Body System[3],[4],[5]
| Body System | Clinical Manifestations |
|---|---|
| Urinary | Oliguria, anuria, proteinuria, and hematuria |
| Cardiovascular | Edema, hypertension and heart murmurs (due to fluid overload), dysrhythmias (due to hyperkalemia), and pericarditis (in advanced stages) |
| Respiratory | Dyspnea (difficulty breathing) due to fluid overload |
| Neurological | Confusion or cognitive changes due to uremic toxins affecting the brain (called cerebral encephalopathy) |
| Gastrointestinal | Anorexia, nausea, metallic taste in mouth (uremic taste), gastritis or peptic ulcer disease, and gastrointestinal bleeding due to uremic platelet dysfunction |
| Integumentary | Pallor, pruritus, and uremic frost (rare, indicates severe uremia) |
| Musculoskeletal | Bone pain or fractures due