12.5 - 12.7: Nephrolithiasis and Chronic Renal Failure Flashcards
UTIs are defined as an infection of what three organs?
Urethra, Bladder, or Kidney
True or false: sex is a risk factor for UTIs
True
What are the s/sx of cystitis? Are systemic signs usually present?
- Dysuria, frequency, urgency, and suprapubic pain
- Usually no systemic signs
What will a UA show with cystitis?
Cloudy urine with more than 10 WBC/hpf
What will a urine dipstick test show with a cystitis?
Positive leukocyte esterase and nitrites
What will a culture show with cystitis?
More than 100,000 colony forming units
What are the 5 bacteria that cause UTIs? Which is most common?
- E.coli
- Staph saprophyticus
- Klebsiella pneumoniae
- Proteus mirabilis
- Enterococcus faecalis
Ammonia scented urine = what infx?
Proteus mirabilis
What is sterile pyuria? What does this suggest?
Pyuria with negative urine cultures
Suggests urethritis d/t chlamydia or gonorrhea
What is a major, physiological risk factor for the development of pyelonephritis?
Vesicoureteral reflux
What are the s/sx of pyelonephritis? (4)
- Fever
- Flank pain
- WBC casts
- Leukocytosis
What causes the flank pain with pyelonephritis?
Sensitization of the nerves that innervate the capsule of the kidney
What are the three most common pathogens of pyelonephritis?
- E.coli
- Klebsiella
- Enterococcus faecalis
What is chronic pyelonephritis, and what causes it?
Interstitial fibrosis and atrophy of tubules d/t multiple bouts of acute pyelonephritis, usually coincides with vesicoureteral reflux
What is the characteristics scarring pattern in the kidneys of vesicoureteral reflux?
Scarring of upper and lower poles
What are the histological characteristics of atrophic tubules 2/2 chronic pyelonephritis?
Eosinophilic proteinaceous material within the atrophic tubules, that appear like the colloid of the thyroid
“thyroidization”
What is thyroidization?
Eosinophilic proteinaceous material within the atrophic tubules, that appear like the colloid of the thyroid
What types of casts are seen in the urine with chronic pyelonephritis?
Waxy casts
What, very generally, are the two risk factors for the development of nephrolithiasis?
- High concentration of solute
- Low urine volume
How fast are stones passed?
Within a few hours
What is the most common type of renal calculi?
Ca oxalate and/or Ca phosphate
What are the causes of Ca oxalate renal stones?
Idiopathic hypercalciuria, but also hypercalcemia and related causes
What GI disease tends to produce Ca oxalate renal calculi? Why?
- Crohn’s disease
- Damage to the enterocytes increases oxalate reabsorption, leading to Ca crystallization
What is the treatment for Ca oxalate crystals? Why?
HTZ–Ca sparing diuretic
What diuretics are absolutely contraindicated with Ca oxalate stones? Why?
Loop diuretics, since these will increase tubular Ca levels
What is the most common cause of ammonium magnesium phosphate renal calculi? Why?
Infection with urease positive organisms (e.g. proteus vulgaris or Klebsiella)
This leads to alkalinization of the urine
What is the treatment for ammonium magnesium phosphate renal calculi?
Surgical removal of stone and eradication of pathogen
What is the classic shape of ammonium magnesium phosphate renal calculi?
Staghorn
What is significant about uric acid crystals in terms of detection?
Radiolucent
What are the only radiolucent renal calculi?
Uric acid crystals
What are uric acid renal calculi associated with?
- Hot climate
- acidic pH
- Gout
- Myeloproliferative disease
Why are uric acid stones associated with myeloproliferative diseases?
Increased cellular turnover leads to increase in uric acid
What is the treatment for uric acid stones?
Hydration and alkalinization of the urine (K HCO3)
-Allopurinol with gout
In whom are Cysteine crystals usually seen? Why?
Children d/t cystinuria
What is the defect in hereditary cystinuria?
Genetic defect of tubules that results in decreased reabsorption of cystine (and COAL amino acids)
What are the characteristics of cystine calculi?
Staghorn calculi
What is the treatment for cysteine renal calculi?
Hydration and alkanization of the urine
What is a staghorn calculus? What are the two types calculi that forms these?
Renal calculus that involves the entire calyx
Cysteine
AMP stones
What types of stones are seen with alkaline urine? Acidic?
Alkaline = ammonium, magnesium, phosphate
Acidic = uric acid stones
End stage kidney failure results from damage to what part of the kidney?
Any-glomerular, tubular, inflammatory or vascular insults
What are the three most common causes of ESRD?
- DM
- HTN
- Glomerular disease
Why does uremia cause platelet dysfunction?
Uremia Inhibits platelet adhesion aggregation
What, generally, is uremia?
Increased nitrogenous waste products within the blood
What are the s/sx of uremia? (heart, hematological, CNS, skin)
- Pericarditis
- Platelet dysfunction
- Encephalopathy with asterixis
- Deposition of urea crystals in the skin
What is asterixis?
- a tremor of the hand when the wrist is extended
- caused by abnormal function of the diencephalic motor centers in the brain, which regulate the muscles involved in maintaining position.
What are the latin roots of asterixis?
a = not Asterixis = fixed position
What, generally, causes asterixis?
- Metabolic encephalopathy
- Acute respiratory failure
- Hepatic encephalopathy
Why is the HTN with uremia?
Retention of salt and water
What is the metabolic disturbance common to uremia?
Hyperkalemia with metabolic acidosis
What is the hematological abnormality with uremia? Why?
Anemia d/t loss of EPO
What cells produce EPO?
Renal peritubular, interstitial cells
Why is there hypocalcemia seen with uremia? (2)
- Decreased 1-alpha-hydroxylase
- Hyperphosphatemia will bind Ca
What are the cells that contain 1-alpha-hydroxylase?
Renal peritubular, interstitial cells
What causes the osteitis fibrosa cystica with renal failure?
Loss of Ca leads to increased PTH, which causes bone resorption
What causes osteomalacia in renal dysfunction?
Cannot mineralize the osteoid made by the osteoblasts
What is the main cause of osteoporosis with ESRD?
Leaching of Ca from bone over time d/t acidosis and the use of bone as buffer
What are the two treatment options for ESRD?
- Dialysis
- Renal transplant
What happens to the kidneys with chronic dialysis?
Shrunken kidneys with cysts
Patients who are on chronic dialysis are at an increased risk for what cancer?
Renal cell carcinoma
How can you differentiate cysts 2/2 PKD and from dialysis in ESRD?
- PKD = large kidneys with cysts
- ESRD = small, fibrotic kidney with cysts
