Renal failure, also called kidney disease, can be defined as damage to the kidneys the reduces the functioning of the kidneys. (1) This disease can be acute or chronic. In acute renal failure (ARF) the onset is rapid, causing an abrupt decline in the kidneys ability to excrete waste products and maintain fluid and electrolyte balance. This can be seen as a rise in the persons blood urea nitrogen and/or creatinine levels. It can be accompanied by a decrease or cease in the production of urine. (2) ARF can be reversed, meaning it can be considered temporary. It also can be more fatal than chronic renal failure.
Chronic renal failure (CRF) is an onset of symptoms over a longer span of time. Renal function declines more slowly, with the persons glomerular filtration rate (GFR) remaining under 60 ml/min for three months or more. (3) This is also accompanied by a decrease or cease in urine production. CRF cannot be reversed, leading to dialysis and end stage renal disease (ESRD). ESRD is the total and permanent loss of kidney function. (4) CRF can be classified in stages, 1-5. (5)
The population most affected by kidney disease is the elderly (persons 65 and older). (4) the growing numbers can be attributed to people living longer and as we age, our kidney function decreases. Changes in aging kidney function include a decrease in blood flow to the kidneys, impaired renal auto regulation, a decrease in GFR and a decrease in ability to concentrate urine. (2) As we age or kidneys actually decrease in size. (2) Other changes in the kidneys involve atrophy, decreased number of glomeruli and proximal tubule numbers, increased sclerosis, fibrosis, and glomerular volume and the thickening of arteries and arterioles. (2) In general, we are more medicated as we age due to other aliments and conditions and as we grow older, our kidneys are less able to excrete these medications due to these functional and anatomical changes. This causes medications that should be excreted by the kidneys to back-up in our system and damage them. The elderly are written 30% of all prescriptions and purchase 40% of all over the counter medicines. (2)
ARF usually occurs in people that are already renally impaired. Acute tubular necrosis (ATN) is the most common cause of intrarenal ARF. Factors leading up to ATN include infections, inflammation, antibiotic and NSAID use, cancer and other obstructions. (5) Prerenal ARF is caused by acute ischaemic (lack of blood flow) or toxic (sepsis) event and is the second most common cause of ARF in the elderly. (2) The second most common cause for prerenal ARF is uremia. (2) Causes of this include lack of fluid intake, use of diuretics ACE inhibitors, ARBs and NSAIDs, poor cardiac output, and GI fluid loss. (2) The elderly are at a greater risk for developing prerenal ARF because they lose the sensation of thirst resulting in a low fluid intake leading to hypovolemia. An elderly person is at greater risk for developing hypovolemia due to the kidneys decreased ability to conserve sodium which results in water loss as well. (2) Benign prostatic hypertrophy, prostatic carcinoma and pelvic malignancies may lead to a blockage of the outflow of urine. This situation put a person at greater risk of developing postrenal ARF. (2) This risk increases with age. (2)
The leading risk factor for developing CRF is diabetes mellitus and hypertension is the second most common cause. (3) Other risk factors include diseases of the glomerulus, tubules, urinary tract, and cardio vascular system, infections, and genetic conditions. (5) Most people with CRF develop anemia, anorexia, N/V, peptic ulcers, hypertension, hyperlipidemia, heart failure, and pericarditis.
The prevention of developing CRF is centered on the diagnosis of diseases that lead to it and keeping those diseases under control. (5) It is helpful to know your blood pressure…