PATHO - Renal/Repro

• Risk Factors for Acute Renal Dysfunction


  • Hypo - tension
  • Excessive exposure to aminoglycosides
  • Hemoglobin - uria and myoglobin - uria
  • Dehydration
  • Pre-existing renal disease
  • Chronic hypertension
  • Exposure to radiocontrast dyes
• 62% of people with acute renal dysfunction have more than one risk factor
• Acute Renal Dysfunction

  • Sudden increase in nitrogenous waste products
  • Urea nitrogen (BUN) – from protein in diet
  • ^^normal range is <20
  • ^^however, a high BUN does not necessarily mean kidney disease
  • Creatinine (Cr) – from muscle
  • Decrease in urine output to < 1 mL/kg/hr
  • ^^Especially problematic if < 30 mL/hr in adults
• Prerenal Dysfunction


  • Any condition that directly or indirectly decreases renal perfusion
  • Can be caused by hypotension, heart failure, shock, or hemorrhage
  • May be due to reduced cardiac output or severe hypovolemia
• Causes for a reduction in cardiac output and causes of severe hypovolemia

  Burns

  hemorrhage
• Intrarenal Dysfunction


  • Direct damage to renal tissue (glomerulus)
  • Nephrotoxic medications (aminoglycosides)
  • NSAIDs such as ibuprofen
  • ^^these meds decrease prostaglandins and decrease blood flow to kidney, which can lead to ischemia.
  • Autoimmune diseases
  • Untreated hypertension
  • ^^result of overactivation of RAAS
  • Uncontrolled diabetes
• Postrenal Dysfunction


  • Obstructive uropathy preventing urine outflow from the kidney
  • Common causes include: Kidney stones in the ureter, Prostate enlargement, Bladder cancer
  • Urine backs up leading to hydronephrosis (water in kidney). The urine is toxic to nephron cells. Urine stagnation increases risk of infection.
• Acute Tubular Necrosis


  • Common cause of renal disease
  • With ischemia, cells slough into the tubular lumen blocking it, preventing fluid to flow through the lumen, reducing urine formation.
  • The blocked lumen contributes to further ischemic injury of the cells lining the tubules.
• Glomerulonephritis


  • Can start as acute, then develop into end-stage renal disease
  • Immune complexes (commonly following infections caused by streptococci) cause inflammation and membrane damage
  • Seen suddenly 7 to 21 days after strep infection
• What type of hypersensitivity reaction is acute glomerulonephritis? Type 3
• Goodpasture's Syndrome


  • Acute, rapidly progressive form of glomerulonephritis cause by circulating antibodies to the glomerular basement membrane.
  • Auto-immune disease of unknown etiology
  • Persons with particular HLA tissue types are more susceptible
  • T cells play a role in the initiation of the disorder
• Nephrolithiasis


  • Formation of kidney stones, or calculi.
  • 12% of men, 7% of women
  • Dehydration increases risk
  • Recurrence is common
• Types of Nephrolithiasis

  • Calcium Oxylate – 75-80% of all stones
  • Struvite – (magnesium, ammonium, phosphate), 15%
  • Uric Acid – 7%
  • Cystine – <1%
• Predisposing Factors for Nephrolithiasis

  • Age > 40 years
  • Gender: male
  • Dietary (purines, calcium, oxalate)
  • High sodium diet
  • Gastric bypass surgery
  • Hypercalciuria, hyperparathyroidism, hyperuricemia
  • Inflammatory bowel disease
  • Dehydration
• Pyelonephritis


  • Infection of renal pelvis and interstitium
  • Acute or chronic
  • Bacteria usually ascend from lower urinary tract
  • Most common cause is bacterial infection (E.coli, Proteus, Pseudomonas), that may result from urine reflux or obstructions
  • 250,000/yr in US of which 200,000 are hospitalized
• Uncomplicated, acute pyelonephritis

  Usually responds well to antibiotic therapy and resolves in about two weeks
• Chronic pyelonephritis

  Involves chronic inflammation, scarring and fibrosis and can lead to chronic renal failure
• Polycystic Kidney Disease


  • Most common form is autosomal-dominant
  • Most common hereditary cause of renal disease
  • Accounts for 6 to 8% of dialysis patients
  • Also susceptible to disorders of other organs including the liver, pancreas, and spleen.
  • May also experience heart valve problems and cerebral aneurysms.
• Polycystic Kidney Disease

  • Defect in polycystin-1 or plycystin-2
  • ^^these chemicals are supposed to sense changes in calcium. a defect in them malfunction, and cysts form in response.
  • Fluid-filled cysts in both kidneys proliferate within the kidneys and fibrotic changes occur over time.
  • Progression to renal failure is slow, rarely before age 40.
• Risk Factors for Chronic Renal Failure

  • Family history
  • Age > 60 years
  • Atherosclerosis
  • Chronic glomerulonephritis
  • Diabetes
  • Hypertension
  • Nephrotoxic medications
• Renal Insufficiency

  Decline in GFR to about 25% of normal.
• Renal Failure

  Decline in GRF to 15-20% of normal
• End-Stage Renal Failure

  10% or less of normal GFR
• One does not see actual symptoms of renal failure until 75% or greater of renal function is lost. Why?? Because your body can still function with about 25% or more.
• End Stage Renal Disease 


  Chronic kidney disease that has reached less than 10% of kidney function
• End-Stage Renal Disease (ESRD)

  • Requires renal replacement therapy or a kidney transplant
  • Peritoneal dialysis: catheter is inserted in abdomen
  • Hemo - dialysis: shunt or graft with venous access
  • Symptoms: nausea, vomiting, fatigue, weakness, decreased mental sharpness, persistent itching from urate crystals
• Renal Cell Carcinoma

  • 85% of all renal neoplasms
  • Associated with smoking, obesity
  • Manifestations: Hematuria, flank pain, Palpable flank mass, Weight loss, fatigue, anemia
  • 5-year survival is 60%
  • Better prognosis if confined to capsule
• Neuromuscular Bladder Control

  • Detrusor muscle fibers are arranged in spiral, longitudinal, and circular layers - they are designed to squeeze
  • Alpha adrenergic fibers relax the detrusor muscle while they tighten the internal sphincter of the bladder neck - this keeps urine in the bladder
  • Stretching of the bladder signals the parasympathetic nervous system to contract the detrusor muscle and relax the internal sphincter - aka. urination
• Bladder capacity

  Bladder usually holds 300 to 400 mL
• Micturition (urination) reflex


  Spinal cord coordinates the reflex, cortex can override it (conscious decision to urinate)
• Benign Prostatic Hypertropy

  • a type of obstructive uropathy
  • with these patients, Caution on how much urine to let out at a time following placement of a Foley catheter because it can cause hematuria and sudden hypo - tension
• Lower Urinary Tract Infections (UTIs)

  • More prevalent in women than men
  • Cloudy, strong smelling urine and hematuria
  • If untreated, can ascend resulting in pyelonephritis
  • Most commonly caused by E. coli, others may include Proteus, Pseudomonas, Streptococci, Staphylococcus, and Klebsiella
• Urolithiasis


  • Can be kidney stones that have moved and wedged themselves in the ureters
  • Can form in the bladder with low fluid intake, low urine production, leading to highly concentrated urine and may result in stone development
• Types of Urinary Incontinence

  • Stress incontinence – with coughing or sneezing or laughing
  • Urge incontinence ("overactive bladder")
  • Overflow incontinence – chronic distention, BPH is frequent cause in men
  • Neurogenic bladder – interruption of sensory nerves between bladder and spinal cord (can be caused by Multiple sclerosis and spinal cord injury)
  • Functional incontinence – Cause by CNS problems such as stroke, dementia, delirium
• Bladder Cancer

  • Although not common, is the most common type of urological cancer
  • 3x more common in men and more common in Caucasians
  • Average age at diagnosis is 73
  • Most are related to environmental exposure
  • Cigarette smoking is a major risk factor
  • Occupational exposure to various organic chemicals
• Structural Abnormalities in Children

  • Congenital abnormalities 1:500 newborns
  • Kidneys do not ascend from pelvis to abdomen
  • Kidneys fuse as they ascend – causing a single U-shaped kidney
  • Structural anomalies account for about 45% of renal failure in children, many are linked to gene defects
• Hypospadias


  • Urethral meatus is located on the ventral side (under surface) of the penis
  • Cause is multifactorial: genetics, endocrine, environmental factors, advanced maternal age, and low birth weight
• PEDIATRIC: Acute poststreptococcal glomerulonephritis


  • Immune complex mediated
  • Most common following throat or skin infection with Group A b-hemolytic streptococci (although other bacteria and viruses may be responsible)
  • Begins 1-2 weeks after infection
  • Can result in oliguria and hypertension
• PEDIATRIC: Urinary Tract Infection


  • Acute cystitis
  • Most common organism – Escherichia coli
  • Usually due to retrograde movement of gram-negative bacilli into the urethra and bladder
  • Teach child to wipe from front to back
  • More common in girls – avoid "bubble baths"
• PEDIATRIC: Wilms Tumor


  • One of the most common neoplasms in Children (most frequently diagnosed 3-5 yeard old).
  • Tumor is comprised of several embryonic cell types.
  • Other congenital deformities of the G.U. tract are often present
  • Tumors generally grow as an isolated mass and may be encapsulated to some degree.
  • Growing tumor may displace and functional renal tissues
  • Grading: (Stage I-IV)
  • Stage I – limited to kidney, excised intact
  • Stage IV – Systemic metastasis are present
  • Long Term Survival is >80% with Aggressive Treatment