Chapter 10: Peripheral Neuropathy and Chronic Kidney Disease

Objectives

On completion of this chapter, the student/practitioner will be able to:

• Discuss renal physiology and the function of the kidneys.

• Define the possible etiologies and clinical characteristics of chronic kidney disease.

• Compare the various methods of dialysis.

• Describe the various peripheral neuropathies associated with chronic kidney disease.

Key Terms

• Capillary filtration coefficient

• Chronic kidney disease

• Glomerular filtration rate

• Hemodialysis

• Renal blood flow

Introduction

Following a brief overview of renal physiology and chronic kidney disease (CKD), this chapter discusses the interaction between kidney disease and peripheral neuropathy. With increasing life expectancy and the increased prevalence of diabetes mellitus and hypertension, CKD, also known as chronic renal failure, chronic renal insufficiency, and chronic kidney failure, now affects 26 million Americans.¹

The primary function of the kidney is to remove metabolic waste products and excess water from the body. In early stages of CKD, symptoms rarely occur. Symptoms may not appear until kidney function is less than one tenth of normal. The final stage of CKD is called end-stage renal disease (ESRD). The two most common causes of CKD are diabetes and uncontrolled high blood pressure. Less common etiologies include renal artery atherosclerotic disease, genetic diseases such as polycystic kidney disease, drug interaction, autoimmune disorders such as systemic lupus erythematosus and scleroderma, glomerulonephritis, renal calculi, and reflux nephropathy.^2–4 Culturally, African Americans, Hispanics, Pacific Islanders, American Indians, and adults older than age 60 are at greater risk for the development of CKD compared with Caucasians and northern Asian groups.^2,3

Presenting symptoms include anorexia, malaise, pruritus, dry skin, and weight loss. Later symptoms include drowsiness and confusion, changes in skin pigmentation, excessive thirst, insomnia, edema, and peripheral neuropathy.^2,3 A wide variety of neuropathies are associated with CKD because of the strong correlation of diabetes and CKD and the large amount of downstream corporal system impairment associated with CKD.

Functions of the Kidney

The kidneys serve multiple functions. The first is to rid the body of waste materials and products that are either ingested or produced by metabolism. A second function is to control the volume and composition of the body fluids. For water and virtually all electrolytes in the body, balance between intake (secondary to oral or parenteral ingestion or metabolic production) and output (secondary to excretion or metabolic consumption) is maintained largely by the kidneys. The regulatory function of the kidney allows cells to function in an optimally stable metabolic environment (Box 10-1).