1. Chapter 33 Disorders of Renal Function

2. Disorders of the Kidneys
Subject to many of the same types of disorders that affect other body structures
Developmental defects
Infections
Altered immune responses
Neoplasms

3. Fetal Anomalies Most common: anomalies in shape and position
Less common are disorders involving:
A decrease in renal mass (e.g., agenesis, hypogenesis)
A change in renal structure (e.g., renal cysts)

4. Organ Development Dysgenesis Failure of an organ to develop normally
Agenesis
Complete failure of an organ to develop
Hypoplasia
Failure of an organ to reach normal size

5. Potter Syndrome
Characteristic facial features of newborns with renal agenesis:
Eyes widely separated and have epicanthic folds
Ears low set
Nose broad and flat
Chin receding
Limb defects often present

6. Causes of Neonatal Renal Failure With Potter Phenotype
Cystic renal dysplasia
Obstructive uropathy
Autosomal-recessive polycystic disease
Unilateral agenesis (uncommon)

7. Cystic Disease of the Kidney
Definition
Fluid-filled sacs or segments of a dilated nephron
Causes
Tubular obstructions that increase intratubular pressure
Changes in the basement membrane of the renal tubules that predispose to cystic dilation

8. Types of Cystic Disease of the Kidney
Simple and acquired renal cysts
Medullary cystic disease
Polycystic kidney disease
Autosomal-recessive polycystic kidney disease
Autosomal-dominant polycystic kidney disease

9. Causes of Urinary Tract Obstruction
Developmental defects
Calculi (stones)
Pregnancy
Benign prostatic hyperplasia
Scar tissue resulting from infection and inflammation
Tumors
Neurologic disorders such as spinal cord injury

10. Damaging Effects of Urinary Obstruction
Stasis of urine
Predisposes to infection and stone formation
Development of backpressure
Interferes with renal blood flow and destroys kidney tissue

11. Manifestations of Urinary Obstruction
Depend on
Site of obstruction
Cause
Rapidity with which the condition developed
Common symptoms
Pain
Signs and symptoms of UTI
Manifestations of renal dysfunction

12. Kidney Stones Definition
Crystalline structures that form from components of the urine
Requirements for formation
Nidus formation
Urinary environment that supports continued crystallization of stone components

13. Factors Influencing the Formation of Kidney Stones
Concentration of stone components in the urine
Ability of stone components to complex and form stones
Presence of substances that inhibit stone formation

14. Question
Which of the following conditions does not lead to stone formation?
Acidic pH
Supersaturated urine
Urine stasis
High Na+ concentration

15. Answer Acidic pH Supersaturated urine Urine Stasis
High Na+: Sodium concentration has nothing to do with stone formation, but all the other factors listed can lead to kidney stone development.

16. Types of Kidney Stones Calcium stones Oxalate or phosphate
Magnesium ammonium phosphate stones
Uric acid stones
Cystine stones

17. Kidney Stone Treatment
Preventive
Dietary restriction
Calcium salt supplementation
Thiazide diuretics
Cellulose phosphate
Treatment for pain
Antibiotic for infection
Removing stones
Ureteroscopic removal
Percutaneous removal
Extracorporeal lithotripsy
Diagnosis
Urinalysis
Radiography
Intravenous pyelography
Ultrasonography

18. Types of Urinary Tract Infections
Asymptomatic bacteriuria
Symptomatic infections
Lower UTIs
Cystitis
Upper UTIs
Pyelonephritis

19. Protective Mechanisms
Washout phenomenon
Mucin layer
Local immune responses
Normal flora of the periurethral area in women
Prostate secretions in men

20. Causes of UTIs Most uncomplicated UTIs caused by Escherichia coli
Other uropathic pathogens include:
Staphylococcus saprophyticus in uncomplicated UTIs
Non-E. coli gram-negative rods (Proteus mirabilis, Klebsiella pneumoniae, Enterobacter, Pseudomonas, and Serratio)
Gram-positive cocci (Staphylococcus aureus, Group B Streptococcus) in complicated UTIs
Most caused by bacteria that enter through the urethra

21. Causes of UTIs Associated With Stasis of Urine Flow
Anatomic obstructions
Urinary tract stones
Prostatic hyperplasia
Pregnancy
Malformations of the ureterovesical junction
Increased pressure resulting in reflux

22. Causes of UTIs Associated With Stasis of Urine Flow (cont.)
Functional obstructions
Neurogenic bladder
Infrequent voiding
Detrusor (bladder) muscle instability
Constipation

23. Characteristics of Acute Episode of Cystitis
Frequency of urination (as often as every 20 minutes)
Lower abdominal or back discomfort
Burning and pain on urination (dysuria)
Cloudy and foul-smelling urine on occasion

24. Special Considerations of UTI Patients
Sexually active women
Pregnant women
Age-related effects
Infants
Toddlers
Adolescents
Adults
Elderly

25. Diagnosis and Treatment of UTIs
Diagnosis based on symptoms and on examination of the urine for the presence of microorganisms
X-ray films, ultrasonography, CT, and renal scans are used to identify contributing factors.
Urine dipstick
Treatment of UTI is based on the pathogen causing the infection

26. Question Is the following statement true or false?
Static urine flow will predispose a patient to development of a UTI.

27. Answer
True: Static urine flow will predispose a patient to development of a UTI.

28. Characteristics of Glomerulonephritis
Immune mechanisms
Glomerular antibodies
Circulating antigen–antibody complexes
Characteristics
Hematuria with red cell casts
Diminished glomerular filtration rate (GFR)
Azotemia (presence of nitrogenous wastes in the blood)
Oliguria
Hypertension

29. Causes of Glomerulonephritis
Diseases that provoke a proliferative inflammatory response of the endothelial, mesangial, or epithelial cells of the glomeruli
The inflammatory process:
Damages the capillary wall
Permits red blood cells to escape into the urine
Produces hemodynamic changes that decrease the GFR

30. Types of Glomerular Diseases
Acute proliferative glomerulonephritis
Rapidly progressive glomerulonephritis
Nephrotic syndrome
Membranous glomerulonephritis
Minimal change disease (lipoid nephrosis)
Focal segmental glomerulosclerosis
IgA nephropathy
Chronic glomerulonephritis

31. Cellular Changes in Glomerular Disease
Proliferative
Endothelial
Mesangial
Leukocyte
Crescent formation
Basement membrane thickening
Sclerosis
Fibrosis
Diffuse glomerular changes
Focal glomerular changes
Segmental glomerular changes
Mesangial changes

32. Urinary Changes in Glomerulonephritis
Proteinuria
Hematuria
Pyuria
Oliguria
Edema
Hypertension
Azotemia

33. Tubulointerstitial Disorders
Damage to the proximal, loop, or distal portion of the nephron
Acute tubular necrosis
Renal tubular acidosis
Pyelonephritis
Effects of drugs and toxins

34. Proximal and Distal Tubular Acidosis
Renal tubular acidosis
Proximal tubular disorders that affect bicarbonate reabsorption
Distal tubular defects that affect the secretion of fixed metabolic acids

35. Major Groups of Renal Neoplasms
Embryonic kidney tumors occurring during childhood
Wilms tumor
Onset at 3–5 years
In one or both kidneys
Wt1 mutation on chromosome 11
Adult kidney cancers
Renal cell carcinoma

36. Question Glomerulonephritis will result from which of the following?
Basement membrane thickening
Sclerosis
Fibrosis
Hypercellularity
All of the above

37. Answer Basement membrane thickening Sclerosis Fibrosis
Hypercellularity
All of the above: Each of these changes can lead to glomerulonephritis.