PathoPhysiology Chapter 27

1. CHAPTER 27
INTRARENAL DISORDERS

2. COMMON MANIFESTATIONS OF
KIDNEY DISEASE
Pain
• Renal pain generally felt at costovertebral
angle
• Pain transmitted to the spinal cord between
T10 and L1 by sympathetic afferent neurons;
may be felt throughout dermatomes of T10-L1
• Due to distention and inflammation of the
renal capsule, has a dull, constant character

3. COMMON MANIFESTATIONS OF
KIDNEY DISEASE (CONT.)
Abnormal Urinalysis Findings
• Provides a foundation for the differential
diagnosis of renal dysfunction
• Dipstick and microscopic urinalysis results
provide clues to intrarenal pathologies

4. COMMON MANIFESTATIONS OF
KIDNEY DISEASE (CONT.)

5. COMMON MANIFESTATIONS OF
KIDNEY DISEASE (CONT.)
Other Diagnostic Tests
• KUB identifies gross abnormalities related to size,
position, and shape (may show renal calculi)
• Renogram/renal scan shows renal vasculature
• Ultrasonography differentiates tissue
characteristics
• CT/MRI used to provide detailed information
about the vasculature and tissue

6. CONGENITAL ABNORMALITIES
Renal Agenesis and Hypoplasia
• Relatively rare; associated with other
congenital abnormalities
• Bilateral renal agenesis not compatible with life
• Unilateral renal agenesis results in
compensatory hypertrophy of functional
kidney
• A single normal kidney is sufficient to maintain
normal renal function

7. CONGENITAL ABNORMALITIES
(CONT.)
Cystic Kidney Diseases
• Genetically transmitted renal disorder resulting
in cysts that can expand and disrupt urine
formation and flow; may be localized to one
area or affect both kidneys
• Autosomal recessive forms are evident at birth
• Autosomal dominant types cause symptoms
later in life
• Renal failure necessitates dialysis or
transplantation

8. NEOPLASMS
Benign Renal Neoplasms
• Symptoms depend on the size; may be
asymptomatic until large enough to form
palpable abdominal mass, hematuria, and
flank pain
• Usually diagnosed with renal ultrasound
and/or CT scan
• Nephrectomy remains treatment of choice

9. NEOPLASMS (CONT.)
Renal Cell Carcinoma
• May have familial pattern
• Risk factors include smoking and obesity
• Usually asymptomatic until advanced;
presenting S/S include CVA tenderness,
hematuria, palpable mass
• Nephrectomy is typical treatment;
metastases may be particularly resistant to
radiation, immunotherapy and
chemotherapy

10. NEOPLASMS (CONT.)

11. NEOPLASMS (CONT.)
Nephroblastoma (Wilms Tumor)
• Most common kidney cancer in children
• Identified by palpable abdominal mass; may
also have pain, hypertension, and/or
hematuria
• Nephrectomy, radiation therapy, and
chemotherapy are used for treatment;
excellent cure rate

12. INFECTION
Acute Pyelonephritis
• Infection of renal pelvis and parenchyma
usually due to an ascending urinary tract
infection
• CVA tenderness a classic sign
• Accompanied by fever, chills, N/V, anorexia
• Presence of WBC casts is indicative of upper
UTI
• Should be promptly managed with
antimicrobials to avoid decreased renal
function

13. INFECTION (CONT.)

14. INFECTION (CONT.)
Chronic Pyelonephritis
• Can result in chronic kidney disease
• Usually associated with vesicoureteral reflux
or obstructive process leading to persistent
urine stasis
• Ongoing inflammation causes fibrosis and
scarring and loss of functional nephrons
• Diagnosed by renal imaging
• Treatment includes correction of underlying
processes and extended antimicrobial
therapy

15. OBSTRUCTION
Renal Calculi (Nephrolithiasis)
• Obstructive processes result in urine stasis,
predisposing to infection and structural
damage
• Common causes include stones, tumors,
prostatic hypertrophy, and strictures of the
ureters or urethra
• Renal stones are most common

16. OBSTRUCTION (CONT.)

17. OBSTRUCTION (CONT.)
Renal Calculi (Nephrolithiasis)
• Complete obstruction leads to
hydronephrosis, decreased GFR, and
ischemic damage due to increased
intraluminal pressure
• Prolonged postrenal ARF may result in ATN
and CKD
• Stones tend to form in urinary tract due to
solute supersaturation, low urine volume, and
abnormal urine pH

18. OBSTRUCTION (CONT.)
Renal Calculi (Nephrolithiasis)
• Most stones composed of calcium crystals;
others include uric acid, struvite, cystine, and
stones associated with certain medications
• Stationary stones usually asymptomatic; stone
migration causes intense renal colic pain
abrupt in onset and may radiate; N/V,
diaphoresis is common

19. OBSTRUCTION (CONT.)
Renal Calculi (Nephrolithiasis)
• Most stones pass spontaneously
• Other interventions may be necessary
including lithotripsy or endoscopic
approaches
• Stones tend to recur; prevention enhanced
by high fluid intake to dilute the urine and
dietary changes based on the type of stone

20. GLOMERULAR DISORDERS
• Glomerulopathies alter glomerular capillary
structure and function
• Damage mediated by immune processes
• May result in some combination of hematuria,
proteinuria, abnormal casts, decreased GFR,
edema, and hypertension

21. GLOMERULAR DISORDERS
(CONT.)
Glomerulonephritis
• Immune response to variety of potential
triggers; may have primary or secondary
etiology
• Attraction of immune cells to the area of
inflammation results in lysosomal degradation
of the basement membrane
• GFR may fall due to contraction of mesangial
cells resulting in decreased surface area for
filtration

22. GLOMERULAR DISORDERS
(CONT.)
Glomerulonephritis
• Treatment may include steroids,
plasmapheresis, and supportive measures
such as dietary and fluid management
• Management of systemic and renal
hypertension
• ESRD is a common outcome of chronic
glomerulonephritis; dialysis or kidney
transplantation may be necessary

23. GLOMERULAR DISORDERS
(CONT.)

24. GLOMERULAR DISORDERS
(CONT.)
Nephrotic Syndrome
• Occurs due to increased glomerular
permeability to proteins
• Urinary loss of 3 to 3.5 g of protein per day
• Proteinuria leads to hypoalbuminemia and
generalized edema; decreased blood colloid
osmotic pressure; increase in liver activity can
cause hyperlipidemia and hypercoagulability

25. GLOMERULAR DISORDERS
(CONT.)

26. GLOMERULAR DISORDERS
(CONT.)
Nephrotic Syndrome
• Treatment is conservative; consists of
symptom management
• Management of underlying process when
identified
• Many cases resolve spontaneously but can
progress to ESRD