In 1982, approximately 20% of the general population of the United States was comprised of persons 55 years and older. It is estimated that by the year 2050, the over-55 age group will amount to 33% of me total population. This growth rate is directly attributed to an increase in the average life expectancy which rose from 47 years in 1900 to approximately 74 years in 1984.1
One major factor which has contributed to increased longevity is the treatment/control/rehabilitation of individuals with chronic health conditions. Approximately 50% of all noninstitutionalized persons over 65 years of age are limited by at least one chronic health condition.2 For example, Hayter3 noted mat 17% of 65 year olds and 26% of 85 year olds have a diagnosis of diabetes. The glucose-insulin imbalance is the primary characteristic of diabetes and is also affected by the aging process.
Aging does slow the rate that substances, such as glucose, are cleared by the kidney. As a result, the elderly have a prolonged glucose clearance time.4
Older persons with diabetes are particularly at risk for developing long-term complications.5 One such complication is chronic renal failure.6 The mean length of time mat elapses between the diagnosis of diabetes and the development of uremia is approximately 20 years.7
According to Lancaster,8 die serum level of insulin is often elevated in uremia because of its increased half-life. This is due to slowed insulin degradation by the kidney. Even though the level of insulin is elevated, its effectiveness is reduced as a result of peripheral resistance. In patients with diabetes, the capillary lumina of the kidney may be gradually obliterated. Fibrinoid necrosis narrows the lumen and weakens the wall of blood vessels causing edema around the affected artery.9
As a result, red blood cells may pass through the damaged wall causing small hemorrhages which can progress to thrombosis. This hemorrhage reduces the blood flow to the kidneys and may cause ischemia. Ischemia increases renin production which stimulates the production of angiotensin. Production of angiotensin may lead to further hypertension. In addition, hypertension may result from fluid and sodium overload or a malfunction of the renin-angiostensin system.10
The Cardiovascular System
The aging process does affect the functioning of the cardiovascular system. Some of the age-related changes include a decreased cardiac output, decreased arterial elasticity, increased peripheral resistance, myocardial valvular rigidity, and poor compensation to stress." Underhill12 stated that most people who have diabetes also are hypertensive, hyperlipidemic, and overweight. These have been identified as risk factors for developing coronary artery disease. Hypertension can produce structural changes in the arterioles throughout the body characterized by fibrosis and hyalinization (sclerosis) of die blood vessel walls.7
Schteingart13 reported that heart attacks occur at least 2Vi times more frequently in diabetic patients and that 75% of the patients wiúi this diagnosis will eventually die of vascular disease. Kannel14 noted mat evidence from the Framingham study indicated that patients with diabetes mellitus had at least a doubled risk of cardiovascular mortality.
According to Underhill12 combinations of risk factors have been proven to produce a synergistic effect. The combined effects of age-related physiological changes and kidney failure increase the likelihood mat individuals will develop cardiovascular problems. Lancaster8 noted that many uremic patients develop heart and vascular disease and die from myocardial infarction.
Treating Chronic Renal Failure
Older diabetic patients with chronic renal failure generally are unable to meet the stringent eligibility criteria established for renal transplant candidates. As a consequence, the treatment method most commonly selected by the older patient has been hemodialysis. More than 45% of the present dialysis population are over the age of 55 years.15
The nurse must understand the complex physiological processes that occur when the older diabetic patient is being dialyzed. Hemodialysis does improve but does not normalize the relationship between insulin and glucose metabolism. Unless both of these substances are appropriately balanced, predictable glucose- or insulin-treated symptomatology may result. Older patients often sustain higher baseline blood sugar levels because of their slowed rate of glucose clearance. Hemodialysis treatment may cause the blood sugar to suddenly drop to a normal or slightly below normal level.
Rapidly decreasing blood sugar levels may cause the older patient to experience insulin shock with the symptoms of diaphoresis, headache, nausea, and trembling. Older patients may exhibit these symptoms for longer periods of time even after the consumption or administration of a glucose-based product. These classic symptoms may also be present when blood sugar levels are in the "normal" range. Obviously, it is essential that baseline blood sugar levels be established for the elderly diabetic hemodialysis patient.
Characteristically, older adults display fewer symptoms of clinical problems which develop more slowly. Usually the older person is able to produce some insulin, therefore, very little fat is catabolized and ketoacidosis does not occur. Urine testing for glucose is less accurate because the renal threshold increases with advancing age and the bladder may contain some residual urine after voiding. Residual urine may cause the glucose measurement to be elevated on second- voided specimens. Drug interactions may also result in inaccurate urine glucose measurement. In addition, diabetic patients are prone to neurogenic bladder and renal vascular disease, thereby increasing their susceptibility to urinary tract infections and pyelonephritis.10
Hemodialysis can produce rapid and profound hypotension in the elderly patient. According to Bailey," the elderly patient has a slower cardiovascular response, decreased cardiac output, and a decreased elasticity of the blood vessel walls. These changes, plus the rapid fluid shifts which may occur during hemodialysis, can lead to hypotension. As a consequence, the nurse should monitor the elderly diabetic patient's blood pressure very closely during hemodialysis.
Hypotension may also be related to the use of certain dialysate solutions. Arterial blood pressure has been reported to fall twice as much during ultrafiltration with acetate as it does with bicarbonate therapy.16 Acetate may contribute to a patient's intolerance to rapid ultrafiltration by affecting the cardiovascular response.17 Using a dialysate bath of bicarbonate may cause less cardiovascular irritation and could benefit such patients.
Some dialysis centers may give a 50% dextrose solution when hypotension occurs. This solution induces a mild osmotic ultrafiltration and prevents the overly rapid correction of plasma urea.18 The nurse should consult the physician regarding the use of such alternative osmotic agents.
Symptoms of hypotension and hypoglycemia can appear to be very similar during hemodialysis treatments. They include sweating, shakiness, headache, nausea, vomiting, and palpitations.13 It is important that the nurse monitor the blood pressure and blood sugar levels of older patients before and after dialysis as well as when patients present symptoms associated with hypotension and hypoglycemia. Paulsen and Joder19 stated that with hemodialysis, carbohydrate calories may be lost if the dialysate is glucose free. In order to avoid hypoglycemia with diabetic patients, additional glucose may be added to the standard dialysate.
Hyperglycemia, aging, renal failure, and hemodialysis treatments can affect vision. Hay ter20 noted that there is overwhelming evidence that prolonged hyperglycemia is detrimental to nerves, minute vessels, and to the lens of the eye. Diabetic patients may develop retinopathy as the result of hemorrhages, neovascularization, retinal scars, cataract formation,13 retinal detachment, and glaucoma.21
The aging process also produces changes in the eye. Malasanos et al4 stated that vision changes in the elderly may range from a loss of elasticity and transparency of the lens to sclerotic changes in the iris. Glaucoma and cataracts develop more frequently in the elderly.
In general, vision problems associated with chronic renal failure are a consequence of hypertension-related changes in the vasculature. Kaplan21 stated that with hypertension, the arterioles become narrow and tortuous and that hemorrhages and exudates can ensue. As renal disease progresses, the calcium-phosphate ratio becomes disrupted. This can lead to the deposition of calcium salts in the conjunctiva and cornea of the eye. I3 These deposits can cause irritation, redness, and tearing of the eye.
Hemodialysis patients are given anticoagulants to prevent the blood from clotting in the extracorporeal system. Kaplan21 noted that anticoagulants can result in retinal hemorrhages, clotted AV shunts can embolize and travel to the eye, and patients with narrow angles may have an acute attack of glaucoma after dialysis.
One factor that has been implicated in the acceleration of retinopathy during dialysis is retinal ischemia. Rapid fluctuations in the intravascular volumes during intermittent therapy can increase retinal ischemia. Nolph22 stated that retinal ischemia is also increased by continued hypertension, hyperglycemia, and systemic heparinization.
The nurse should perform a monthly opthalmoscopic assessment as well as a routine visual inspection of the patient's eyes prior to each dialysis treatment. It is extremely important that the nurse instruct and encourage the patient to report any changes in vision. Complaints of visual distortion, blurring, redness, or pain in the eyes must be recognized as potentially serious and should be reported to the physician.
Adhering to die prescribed diet is of paramount importance for the older diabetic patient with chronic renal failure. Strict dietary compliance is required in order to minimize the sequelae associated with diabetes and renal disease. The standard renal diet is low in protein content and high in carbohydrate-based calories. Naturally, the high carbohydrate diet can lead to diabetic complications. It is critical, however, that the elderly diabetic patient eat the high biological value protein ordered in the diet. Protein loss poses special problems because the diabetic may be malnourished due to poor food intake, vomiting, and catabolic stress.
Nurses must continually support, encourage, and assist the patient to accept and conform to this rigid dietary regimen. It is important that elderly patients be provided with both oral and written instructions regarding tfieir dietary regimen, medications, and prescribed fluid restriction. Nurses must frequently stress and reinforce the importance of adhering to a low sodium and cholesterol diet so that the elderly patient will reduce the amount of fluid weight gained and the amount of nitrogenous waste products in the blood.
In addition, patients must understand the relationship between noncompliance and the potential devastating effects on the cardiovascular system and its sequelae. Complying with the prescribed dietary regimen may allow the elderly patient to delay the need for more aggressive hemodialysis treatment.
Understanding and assessing the pathophysiological changes associated with diabetes, end stage renal disease, and advanced age is a very complex process. For example, many older individuals often display slower clinical responses, less dramatic symptomatology, cardiovascular and sensory changes, as well as other sequelae that may interfere with the identification of a life-threatening situation (eg, infection).
Nurses must be able to accurately assess and establish baseline data about these patients so mat any pamological changes can be more easily identified. Frequent interactions with these patients should allow the nurse to construct individualized care and treatment regimens that provide support and encourage compliance for the growing number of elderly diabetic patients who have developed chronic renal failure.
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- 2. US Department of Commerce Statistical Abstract of the United States, ed ???, Series P-25, Nos. 802, 1980; 888.
- 3. Hay ter J: Why response to medication changes with age? Geriatric Nursing 1981; 2(6):41 1-416.
- 4. Matasanos L. Barkauskas V, Moss M. Stoltenberg-Allen K: Health Assessment, ed 2. St Louis, CV. Mosby. 1981, pp 623-631.
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- 6. Liddle VR: Nutrition for the patient with end stage renal disease, in Lancaster LE (ed): The Patient with End Stage Renal Disease, ed 2. New York. A Wiley Medical Publication, 1984, pp 92-105.
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- 11. Bailey P: Physical assessment of the elderly. Topics ? Clinical Nursing 1981: 3(l):15-19.
- 12 . Underhill S: Coronary artery disease risk factors, in Underhill S. Woods S. Silvarajan E, Halpenny CJ (eds): Cardiac Nursing. Philadelphia, JB Lippincon, 1982, pp 124-148.
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- 17. Graefe V. Milutinovic!! J, Follette WC, Vizzo JC, et al: Less dialysis-induced morbidity and vascular instability with bicarbonate in dialysis. Ann Intern Med 1978; 88(3):332-336.
- 18. Schoengmnd L: Nursing management of the hemodialysis patient, in Schoengmnd L. Balzer P (eds): Renal Problems in Critical Care. New York, John Wiley and Sons. 1985, p 117.
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- 21. Kaplan LJ: Ophthalmic Manifestations of renal disease. Journal of Nephrology Nursing 1985; 2(2):74-76.
- 22. Nolph KD: Chronic peritoneal dialysis in a patient with diabetes mellitus and heart disease. Kidnev lnt 1979; 15:698-708.