Question

CASE STUDY A Nephrosclerosis and Chronic Renal Failure Mr. H., age 68 years, has a long history of hypertension. He has had more headaches recently, his legs and feet are swollen, and he has noticed that more frequent voiding, both during the day and at night, is necessary. He constantly feels tired and does not feel hungry. Mr. H.s blood pressure is 170/110, his pulse is 94, and he has gained 12 pounds in the last 2 months. Diagnostic test findings related to the blood and urine include elevated serum creatinine and urea levels, low serum bicarbonate, low hemoglobin and hematocrit, and low serum sodium. The urine contains protein and has a very low specific gravity. The diagnosis is renal insufficiency, or chronic renal failure, due to nephrosclerosis. 1. Describe how nephrosclerosis leads to chronic renal failure. 2. Explain the cause of the edema and the weight gain. 3. State three factors contributing to fatigue. 4. Explain why Mr. H.: a. is voiding frequently. b. has a very dilute urine. 5. Explain why Mr. H. has: a. high blood pressure. . anemia. 6. List the signs indicating that Mr. H. has progressed into 7. List three reasons why development of pneumonia is a c. metabolic acidosis. uremia, or end-stage renal failure. high risk in Mr. H.

Answer 1

1 Nephrosclerosis consists of sclerosis of the small arteries and arterioles of the kidney.There is decreased blood flow ,which results in patchy blood flow necrosis of the renal parenchyma .Ischaemic necrosis and destruction of glomeruli with subsequent fibrosis also may occur.

2 The main cause of the edema and the weight gain are increase in the renin-angitensin -aldosterone system increases fluid retention and therefore increases weight.Excess fluid alsocauses his feet and legs to swell.

3 The patients heart has to work harder to pump blood because he has a greater blood volume .The kidney has failed therefore it is not producing erythropoietin and this causes a deficiency in redcell production causing less oxygen to circulate.

4 Stage 2 and 3 ,75%nephrons are lost,renal insufficiency,is indicated by change in blood chemistry .GRF is 20% of normal and significant retention of nitrogen wastes in blood.Tubule function is decreased,causing failure to concentrate urine and control secretion and exchange of acids and electrolytes.Osmotic diuresis occurs as the remaining functional nephrons filter increased solute load.This stage marked by excretion of large volumes of dilute urine.

5a High blood pressure is due to renin-angiotensin-aldosterone system causes water and sodium retention which increases blood pressure.

b Anaemia-kidneys are damaged and are not producing erythropoeitin.

c Metabolic acidosis-kidneys arent filtering wastes.

6 Increased blood pressure indicates reduced blood supply to kidney and ischaemia/atropy,stimulating renin secretion.Damage is symptomatic,indicating a late stage of the disease.

7 Decreased erythropoiesis,weakened immune system,susceptible to systemic infection such as pneumonia due to poor tissue resistance related to anaemia,fluid retention and low protein levels.