Chapter 25 Disorders of Renal Function

1. Essentials of Pathophysiology Chapter 25Disorders of Renal Function

2. The kidneys do not begin to develop until the 12th week of gestation and start to function approximately 6 weeks later. • There is just a single theory that applies to kidney stone formation. • Most uncomplicated urinary tract infections (UTIs) are caused by Escherichia coli. • Upper urinary tract infections differ from those of lower urinary tract infections in that they incite an acute inflammatory response with marked systemic manifestations of infection. • Catheter-associated bacteriuria remains the most frequent cause of gram-negative septicemia in hospitalized patients. Pre lecture quiz true/false F F T T T

3. Autosomal dominant polycystic kidney disease (ADPKD) is a systemic disorder that primarily affects the kidneys, resulting in the formation of fluid-filled __________ in both kidneys with the threat of progression to chronic renal failure. • ____________ refers to urine-filled dilatation of the renal pelvis and calices associated with progressive atrophy of the kidney due to obstruction of the outflow of urine. • Most kidney stones are composed of __________. • Nephrotic syndrome is associated with increased glomerular permeability to the plasma __________, resulting in generalized edema. • The __________ phenomenon, the process by which the urine released from the bladder washes out the bacteria out of the urethra, aids in maintaining the sterility of the urine formed in the kidneys and found in the bladder. Pre lecture quiz calcium Hydronephrosis protein sacs washout

4. Cystic disease of the kidney • Simple and acquired renal cysts • Medullary cystic disease • Autosomal dominant polycystic kidney disease • Obstructive disorders • Hydronephrosis • Renal calculi Cystic and Obstructive Disorders

5. Expansion of the kidney with urine (hydronephrosis) • Increased pressure inside the renal capsule • Compartment syndrome compresses blood vessels inside kidney • Renal ischemia • Stasis of urine • Risk of infection • Stones Consequences of Dilation of Renal Tubules or Tract

6. Hydronephrosis

7. Tell whether the following statement is true or false. Hydronephrosis is categorized as a disorder of glomerular function. Question

8. False Rationale:Hydronephrosis is caused by a urinary obstruction, so it is considered an obstructive disorder. The glomerulus is not involved. Answer

9. Saturation theory: urine is supersaturated with stone components • Matrix theory: organic materials act as a nidus for stone formation • Inhibitor theory: a deficiency of substances that inhibit stone formation • Four types of kidney stones: • Calcium stones (i.e., oxalate or phosphate) • Magnesium ammonium phosphate stones • Uric acid stones • Cystine stones Renal Calculi

11. Bacteria usually enter through the urethra • Host defenses include: • Washout phenomenon • Protective mucus • Local immune responses and IgA • Normal bacterial flora Urinary Tract Infections

12. Mr. K is paraplegic. • When in the hospital, he had a catheter • Now he has a high fever and complains of joint and back pain • He has pyuria and reports urgency • BUN is 78 mg/dL(Normal 8-20 mg/dL) • PCR is 4.7 mg/dL (Normal 0.6-1.2 mg/dL) Question: • What complication are you most worried about? Why? Scenario:

13. Tell whether the following statement is true or false: Urinary tract infections (UTIs) are usually caused by a virus. Question

14. False Rationale: UTIs are most often caused by bacteria that enter through the urethra (most common) or the bloodstream. Answer

15. Glomerular capillaries and Bowman’s capsule are both made of epithelial cells sitting on a basement membrane They are so tightly attached to each other that they share one basement membrane The epithelial cells of Bowman’s capsule stand up from the basement membrane on foot processes, leaving pores between the feet for filtration Structure of the Glomerulus Urine Epithelial cell Foot processes Basement membrane Blood in capillary

16. Immune Damage to the Glomerulus Circulating immune complexes lodge in glomerulus Antibodies to glomerular proteins

17. Proliferative: number of cells increase Sclerotic: amount of extracellular matrix increases Membranous: thickness of glomerular capillary wall increases All can decrease the efficiency of filtration Allow blood cells, lipids, or proteins to pass into the urine Glomerular Damage

18. Nephritic syndromes • Proliferative inflammatory response • Nephrotic syndrome • Increased permeability of glomerulus • Mixed nephritic and nephrotic responses • Chronic glomerulonephritis • Glomerular lesions associated with systemic disease Disorders of Glomerular Function Glomerular Problems Tubular Problems

19. Proliferative inflammatory response • RAA pathway activated; hypertension • Inflammatory process damages the capillary wall • Red blood cells escape into the urine • Hematuria with red cell casts • Hemodynamic changes decrease the GFR • Azotemia (presence of nitrogenous wastes in the blood), oliguria NephriticSyndromes

20. Other proteins lost in urine: • Immunoglobulins and complement  immune suppression • Clotting and anticlotting proteins  thrombosis • Proteins that carry other blood components  imbalances in blood components; altered drug dosages NephroticSyndrome

21. Tell whether the following statement is true or false: Nephritic syndromes are characterized by blood in the urine. Question

22. True Nephritic syndromes decrease the permeability of the glomerular capillary membrane, which results in hematuria, HTN, oliguria, and ↓ GFR. Answer

23. A woman has diabetes mellitus • She has severe edema and frothy, cola-colored urine • She has difficulty breathing, with crackles in both lungs • She just finished a course of antibiotics for strep throat • She is also taking corticosteroids for lupus-related arthritis Question: • What are three reasons for her renal problems? Scenario:

24. A woman has diabetes mellitus and lupus and recently had strep throat. • She has severe edema and frothy, cola-colored urine Question: • The doctor says the only way to determine what has caused her glomerular disease is a renal biopsy. Why? Scenario (cont.)

25. Urinalysis show that she is producing: • Urine with 500 mg protein/ day • Contains blood and RBC casts • High level of K+ • Blood tests show: • Hypoalbuminemia • Slightly decreased K+ • She has borderline hypertension Question: • Does she have nephritic syndrome or nephrotic syndrome? Scenario (cont.)

26. Acute tubular necrosis • Pyelonephritis • Acute pyelonephritis • Acute hypersensitivity to drugs • Chronic pyelonephritis • Drug-related nephropathies Tubulointerstitial Disorders

28. Malignant Tumors of the Kidney

29. Mike’s Kidneys