1. Chapter 26 Acute Renal Failure and Chronic Kidney Disease

2. More waste remains in the blood
When Kidneys Fail
Less waste is removed
More waste remains in the blood
Nitrogenous compounds build up in the blood
BUN: Blood urea nitrogen
Creatinine
Renal function approximated by: initial creatinine level/current creatinine level

3. Author: Please add title.

4. Acute Renal Failure Prerenal Postrenal Intrinsic
Decreased blood supply
Shock, dehydration, vasoconstriction
Postrenal
Urine flow is blocked
Stones, tumors, enlarged prostate
Intrinsic
Kidney tubule function is decreased
Ischemia, toxins, intratubular obstruction

5. Question
Which type of acute renal failure (ARF) would be most likely to accompany benign prostatic hypertrophy?
Prerenal
Postrenal
Intrinsic
Extrinsic

6. Answer
b. Postrenal Postrenal ARF occurs when the flow of urine is blocked by kidney stones, tumors, or an enlarged prostate gland. Because the male utethra passes through the prostate, if it is enlarged the urethra may become blocked.

7. Radiocontrast Agents Can Cause ARF
Giving N-acetylcysteine reduces the risk of ARF by 50% in a meta-analysis
Recommended for clients at risk of renal failure who are receiving radiographic contrast media
Diabetics, clients with sepsis
Underlying vascular, renal, or hepatic disease
Receiving other nephrotoxic drugs
(Kellum, J.A. [2003]. A drug to prevent renal failure? Lancet 362, )

8. Why would leg damage cause renal failure?
Scenario
A man developed acute renal failure after emergency surgery for a severed left leg…
He came in with a serum creatinine of 1.2 mg/dL, but now it is 5.6 mg/dL
His BUN is 86 mg/dL
Question:
Why would leg damage cause renal failure?
What is his remaining kidney function?

9. Urine Containing Tubular Cell Casts
Casts are formed when cells are packed together in the tubule lumen
They block the tubule
When the mass of cells washes loose, it appears in the urine

10. Scenario
Mr. J is an alcoholic with kidney problems…
He is severely dehydrated with an infected leg ulcer, benign prostatic hypertrophy, and anemia
His urine is dark and contains myoglobin and tubular cell casts
His creatinine and BUN are both elevated
Question:
What may have caused his acute tubular necrosis?

11. Fewer nephrons are functioning Remaining nephrons must filter more
Chronic Renal Failure
Fewer nephrons are functioning
Remaining nephrons must filter more
Hyperperfusion
Hypertrophy

12. Development of CRF Diminished renal reserve
Nephrons are working as hard as they can
Renal insufficiency
Nephrons can no longer regulate urine density
Renal failure
Nephrons can no longer keep blood composition normal
End-stage renal disease

13. Uremia Uremia = “Urine in the Blood”
Renal filtering function decreases
Altered fluid and electrolyte balance
Acidosis, hyperkalemia, salt wasting, hypertension
Wastes build up in blood
Increased creatinine and BUN
Toxic to CNS, RBCs, platelets
Kidney metabolic functions decrease
Decreased erythropoietin
Decreased Vitamin D activation

14. Question
Which of the following renal disorders is characterized by increased BUN and creatinine levels?
ARF
CRF
Uremia
All of the above
b and c

15. Answer
All of the above
In each disorder listed, the ability to remove nitrogenous waste is diminished. This causes nitrogenous compounds (BUN and creatinine) to accumulate in the blood.

16. Scenario A man has chronic renal failure…
He has high creatinine and BUN, hyperkalemia, acidosis with normal pCO2, and severe anemia
His blood glucose has reached 340 mg/dL one hour after a hospital meal
He complains of having broken two toes in the last few weeks, even though he eats a lot of dairy products for calcium

17. Scenario (cont.)
Question:
What is the most likely cause of his chronic renal failure?
What caused his anemia?
Why are his bones brittle even though he eats dairy products?

18. Cardiovascular Consequences of CRF
less
Decreased blood viscosity +
Increased blood pressure
Decreased oxygen supply
erythropoietin
anemia
lower blood
viscosity
blood flows through
vessels more swiftly
heart rate increases

19. increased workload on left heart
left ventricle dilation and
hypertrophy
not enough oxygen to support LV
contraction
angina
ischemia
LHF

20. Question
Tell whether the following statement is true or false: CRF leads to decreased cardiac output (CO).

21. Answer
True The increased blood pressure (HTN) and hypoxemia that accompany CRF leads to increased myocardial work (the heart has to work harder to meet the metabolic demands of body tissues). Eventually the heart becomes unable to meet these metabolic demands, and CO will decrease.

22. Manifestations of Kidney Failure

23. Types of Dialysis